Дисертації: "Power management technique"

1

Rinaldy. "A technique to incorporate the impacts of demand side management on generation expansion planning." Diss., Virginia Tech, 1992. http://hdl.handle.net/10919/40021.

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2

Acharya, Subrata. "A dynamic slack management technique for real-time distributed embedded systems." Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/3173.

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This work presents a novel slack management technique, the Service Rate Based Slack Distribution Technique, for dynamic real-time distributed embedded systems targeting the reduction and management of energy consumption. Energy minimization is critical for devices such as laptop computers, PCS telephones, PDAs and other mobile and embedded computing systems simply because it leads to extended battery lifetime. Such systems being power hungry rely greatly upon the system design and algorithms for processing, slack and power management. This work presents an effcient dynamic slack management scheme for an energy aware design of such systems. The proposed Service Rate Based Slack Distribution Technique has been considered with two static(FCFS, WRR) and two dynamic(EDF, RBS) scheduling schemes used most commonly in distributed systems. A fault tolerance mechanism has also been incorporated into the proposed technique inorder to use the available dynamic slack to maintain checkpoints and provide for rollbacks on faults. Results show that in comparion to contemporary techniques, the proposed Service Rate Based Slack Distribution Technique provides for about 29% more perfor-mance/overhead savings when validated with real world and random benchmarks.

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3

Chen, Quan. "Risk Management of Cascading Failure in Composite Reliability of a Deregulated Power System with Microgrids." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/52980.

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Due to power system deregulations, transmission expansion not keeping up with the load growth, and higher frequency of natural hazards resulting from climate change, major blackouts are becoming more frequent and are spreading over larger regions, entailing higher losses and costs to the economy and the society of many countries in the world. Large-scale blackouts typically result from cascading failure originating from a local event, as typified by the 2003 U.S.-Canada blackout. Their mitigation in power system planning calls for the development of methods and algorithms that assess the risk of cascading failures due to relay over-tripping, short-circuits induced by overgrown vegetation, voltage sags, line and transformer overloading, transient instabilities, voltage collapse, to cite a few. How to control the economic losses of blackouts is gaining a lot of attention among power researchers. In this research work, we develop new Monte Carlo methods and algorithms that assess and manage the risk of cascading failure in composite reliability of deregulated power systems. To reduce the large computational burden involved by the simulations, we make use of importance sampling techniques utilizing the Weibull distribution when modeling power generator outages. Another computing time reduction is achieved by applying importance sampling together with antithetic variates. It is shown that both methods noticeably reduce the number of samples that need to be investigated while maintaining the accuracy of the results at a desirable level. With the advent of microgrids, the assessment of their benefits in power systems is becoming a prominent research topic. In this research work, we investigate their potential positive impact on power system reliability while performing an optimal coordination among three energy sources within microgrids, namely renewable energy conversion, energy storage and micro-turbine generation. This coordination is modeled when applying sequential Monte Carlo simulations, which seek the best placement and sizing of microgrids in composite reliability of a deregulated power system that minimize the risk of cascading failure leading to blackouts subject to fixed investment budget. The performance of the approach is evaluated on the Roy Billinton Test System (RBTS) and the IEEE Reliability Test System (RTS). Simulation results show that in both power systems, microgrids contribute to the improvement of system reliability and the decrease of the risk of cascading failure.
Ph. D.

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4

Forghani-zadeh, Hassan Pooya. "An Integrated, Lossless, and Accurate Current-Sensing Technique for High-Performance Switching Regulators." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/16164.

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Switching power converters are an indispensable part of every battery-operated consumer electronic product, nourishing regulated voltages to various subsystems. In these circuits, sensing the inductor current is not only necessary for protection and control but also is critical to be done in a lossless and accurate fashion for state-of-the-art advanced control techniques, which are devised to optimize transient response, increase the efficiency over a wide range of loads, eliminate off-chip compensation networks, and integrate the power inductor. However, unavailability of a universal, integrable, lossless, and accurate current-sensing technique impedes the realization of those advanced techniques and limit their applications. Unfortunately, use of a conventional series sense resistor is not recommended in high-performance, high-power switching regulators where more than 90% efficiency is required because of their high current levels. A handful of lossless current-sensing techniques are available but their accuracies are significantly lower than the traditional sense resistor scheme. Among available lossless but not accurate techniques, an off-chip, filter-based method that uses a tuned filter across the inductor to estimate current flow and its accuracy is dependent on the inductance and its equivalent series resistance (ESR) was selected for improvement because of its inherent continuous and low-noise operation. A schemes is proposed to adapt the filter technique for integration by automatically adjusting bandwidth and gain of an on-chip programmable gm-C filter to the off-chip power inductor during the system start-up through measuring the inductance and its ESR with on-chip generated test currents. The IC prototype in AMI s 0.5-um CMOS process achieved overall DC and AC gain errors of 8% and 9%, respectively, at 0.8 A DC load and 0.2 A ripple currents for inductors from 4 uH-14 uH and ESR from 48 mOhm to 384 mOhm when lossless, state-of-the-art schemes achieve 20 40% error and only when the nominal specifications of power component (power MOSFET or inductor) are known. Moreover, the proposed circuit improved the efficiency of a test bed current-mode controlled switching regulator by more than 2.6% at 0.8 A load compared to the traditional sense resistor technique with a 50 mOhm sense resistor.

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5

Yarlagadda, Sriram. "A Battery Management System Using an Active Charge Equalization Yechnique Based on DC-DC Converter Topology." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1306852610.

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6

Somov, Andrey. "Power Management and Power Consumption Optimization Techniques in Wireless Sensor Networks." Doctoral thesis, Università degli studi di Trento, 2009. https://hdl.handle.net/11572/367818.

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A Wireless Sensor Network (WSN) is a distributed collection of resource constrained tiny nodes capable of operating with minimal user attendance. Due to their flexibility and low cost, WSNs have recently become widely applied in traffic regulation, fire alarm in buildings, wild fire monitoring, agriculture, health monitoring, building energy management, and ecological monitoring. However, deployment of the WSNs in difficult-to-access areas makes it difficult to replace the batteries - the main power supply of a sensor node. It means that the power limitation of the sensor nodes appreciably constraints their functionality and potential applications. The use of harvesting components such as solar cells alone and energy storage elements such as super capacitors and rechargeable batteries is insufficient for the long-term sensor node operation. With this thesis we are going to show that long-term operation could be achieved by adopting a combination of hardware and software techniques along with energy efficient WSN design. To demonstrate the hardware power management, an energy scavenging module was designed, implemented and tested. This module is able to handle both alternating current (AC) based and direct current (DC) based ambient sources. The harvested energy is stored in two energy buffers of different kind, and is delivered to the sensor node in accordance with an efficient energy supply switching algorithm. The software part of the thesis presents an analytical criterion to establish the value of the synchronization period minimizing the average power dissipated by a WSN node. Since the radio chip is usually the most power hungry component on a board, this approach can help one to decrease the amount of power consumption and prolong the lifetime of the entire WSN. The following part of the thesis demonstrates a methodology for power consumption evaluation of WSN. The methodology supports the Platform Based Design (PBD) paradigm, providing power analysis for various sensor platforms by defining separate abstraction layers for application, services, hardware and power supply modules. Finally, we present three applications where we use the designed hardware module and apply various power management strategies. In the first application we apply the WSN paradigm to the entertainment area, and in particular to the domain of Paintball. The second one refers to a wireless sensor platform for monitoring of dangerous gases and early fire detection. The platform operation is based on the pyrolysis product detection which makes it possible to prevent fire before inflammation. The third application is connected with medical research. This work describes the powering of wireless brain-machine interfaces.

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7

McGlen, Ryan James. "Advanced thermal management techniques for high power electronics devices." Thesis, University of Newcastle Upon Tyne, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533697.

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8

Davidson, Jonathan. "Advanced thermal modelling and management techniques to improve power density in next generation power electronics." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/8419/.

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This thesis sets out a series of new techniques to improve the thermal management of power electronics. The work is motivated by the increasing impetus to design smaller, more energy efficient electronic power systems for a range of applications, notably electric vehicles. Thermal management is an increasingly important tool which can facilitate improvements in power density through better monitoring and control of system temperatures. This thesis seeks to deliver improvements in implementing this strategy. A review of the state of the art in thermal management is reported, focussing on temperature measurement, thermal characterisation and system modelling techniques. In addition, novel techniques for arbitrary dissipation control and die temperature measurements in semiconductor devices are presented. A novel analysis of the limitations of low-order thermal models is also described. Improvements and applications of these techniques form the basis of this thesis. The pseudorandom binary sequence (PRBS) technique for system identification is applied throughout the thesis to characterise thermal systems. A mathematical analysis is provided, together with a novel technique to determine the minimum gain which can be identified by PRBS techniques in the presence of noise. A novel improvement to the PRBS technique for typically ten times more noise resilient measurements is then developed based on mathematical mixing of different frequency PRBS signals. In parallel, a novel technique is formulated to estimate the temperature throughout a multiple device system using digital IIR filters and PRBS thermal characterisation, which achieves errors of 3-5% when demonstrated practically. By combining these techniques, a comprehensive temperature estimation and control methodology is implemented for a multiple device system under active cooling. Finally, the expansion of the proposed methodologies to steady-state die temperature estimation is presented with comparable accuracy to surface temperature measurements, increasing the usefulness of the developed techniques in a practical setting.

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9

Wang, Xing. "Market-based transmission congestion management using extended optimal power flow techniques." Thesis, Brunel University, 2001. http://bura.brunel.ac.uk/handle/2438/4804.

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This thesis describes research into the problem of transmission congestion management. The causes, remedies, pricing methods, and other issues of transmission congestion are briefly reviewed. This research is to develop market-based approaches to cope with transmission congestion in real-time, short-run and long-run efficiently, economically and fairly. Extended OPF techniques have been playing key roles in many aspects of electricity markets. The Primal-Dual Interior Point Linear Programming and Quadratic Programming are applied to solve various optimization problems of congestion management proposed in the thesis. A coordinated real-time optimal dispatch method for unbundled electricity markets is proposed for system balancing and congestion management. With this method, almost all the possible resources in different electricity markets, including operating reserves and bilateral transactions, can be used to eliminate the real-time congestion according to their bids into the balancing market. Spot pricing theory is applied to real-time congestion pricing. Under the same framework, a Lagrangian Relaxation based region decomposition OPF algorithm is presented to deal with the problems of real-time active power congestion management across multiple regions. The inter/intra-regional congestion can be relieved without exchanging any information between regional ISOs but the Lagrangian Multipliers. In day-ahead spot market, a new optimal dispatch method is proposed for congestion and price risk management, particularly for bilateral transaction curtailment. Individual revenue adequacy constraints, which include payments from financial instruments, are involved in the original dispatch problem. An iterative procedure is applied to solve this special optimization problem with both primal and dual variables involved in its constraints. An optimal Financial Transmission Rights (FTR) auction model is presented as an approach to the long-term congestion management. Two types of series F ACTS devices are incorporated into this auction problem using the Power Injection Model to maximize the auction revenue. Some new treatment has been done on TCSC's operating limits to keep the auction problem linear.

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10

Eriksson, Simon. "System Analysis of Energy-Constrained Quality of Service and Power Management Techniques." Thesis, KTH, Maskinkonstruktion (Inst.), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99457.

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This master’s thesis is a part of the GEODES project, Global Energy Optimization for Distributed Embedded Systems, and deals with the issues regarding energy-constrained Quality of Service , QoS, in real time embedded systems. Due to the development in the areas of embedded systems, new demands have arisen. Especially for mobile devices, the increase of functionality has overrun the development of batteries. To deal with these kinds of problems a new aspect of QoS has become of interest. The new aspect is to bring power awareness into the system. Power awareness means to enable enhancements or guarantees for the lifetime of a device through intelligent software. For online decision making a software component, an energy-constrained QoS manager, is needed. The manager module may be distributed in a system or dispatched locally. The mission is to decrease power consumption by the cost of lesser performance of the system. This procedure is called to introduce system degradation into the system. A lot the research in the power management field targets single components. This thesis aims to investigate the possibilities in system level management. An analysis of existing energy-constrained QoS and power management frameworks and techniques has been made, both on system level and on component level. As a result of the analysis a specification for the interface and policies of an energy-constrained QoS power manager is presented. A fundamental choice in the specification and design was that the system in hand consist of power manageable components , PMCs, which can be seen as atomic black boxes. This modeling choice was shown to be complicated to apply in real life systems and a solution proposal for interdependencies of PMCs is discussed. A design and a prototype, the Power Manager E , PME, module, has been implemented that tries to fulfill the specifications created from the analysis. The design handles both hardware and software as PMCs and optimizes for system performance under an energy constraint, expressed through desired system runtime, set by the user of the system. The prototype is implemented on an i.MX31 platform from Freescale and runs as a module to operating system OSE 5.4 Delta provided by ENEA.
Examensarbetet är en del av GEODES projektet, Global Energy Optimization for Distributed Embedded Systems. Arbetet hanterar frågor som rör energistyrd Quality of Service , QoS, i inbyggda realtidssystem. Genom den senaste utvecklingen inom området inbyggda system har nya krav introducerats. Speciellt för mobila enheter, där tillkomsten av ny funktionalitet har gått snabbare än utvecklingen av batterikapacitet. För att hantera detta så har en ny aspekt av QoS fått större intresse. Den nya aspekten är att utveckla system med en medveten energikonsumtion. Energimedvetenhet innebär mjukvara som möjliggör förbättringar eller garantier för körtiden av systemet, online eller offline. För beslut online krävs en mjukvarukomponent, en mjukvarumodul för energistyrd QoS. Uppdraget för mjukvarumodulen är att minska strömförbrukningen till kostnaden av lägre prestanda hos systemet. Detta förfarande kallas för att införa kontrollerad system degradering i systemet. Forskningen inom området koncentrerar sig mest på att minska energikonsumtionen för enskilda komponenter. I detta examensarbete så är siktet ställt på att hitta metoder som fungerar på systemnivå. En analys av befintliga ramverk och tekniker för mjukvarukontrollerad energikonsumtion samt energistyrd QoS har genomförts, både på systemnivå och på komponentnivå. Resultatet av analysen presenteras av en specifikation för en energistyrd QoS styrmodul anpassad för kontroll på systemnivå. Ett grundläggande antagande i specifikationen och implementeringen var att systemet i fråga består av komponenter med ställbar energiförbrukning. Dessa komponenter kan ses som fristående oberoende funktionaliteter. Modellantagande visade sig vara komplicerat att tillämpa på verkliga system och ett lösningsförslag vid beroenden mellan komponenter diskuteras. En design och en prototyp Power Manager E , PME, har skapats enligt den specifikation som tagits fram i rapporten. Den hanterar både hårdvara och mjukvara som ställbara komponenter och försöker optimera systemets prestanda under krav på energikonsumtion. Kravet ställs av användaren genom en önskad körtid av systemet. Protoypen är byggd på en i.MX31-plattform från Freescale och är en tilläggsmodul till OSE5.4 Delta från ENEA.

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11

Kreinar, David J. "Energy Management Techniques for Hybrid Electric Unmanned Aircraft Systems." University of Dayton / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=dayton159640308960136.

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12

AbuAli, Mohamed. "Techniques for Non-Intrusive Machine Energy and Health Modeling." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1282056290.

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13

Li, Chenxi. "Advanced Load Management Techniques with the Inclusion of Distributed Energy Resources in a Smart Grid." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/17855.

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Smart grid has been under continuous development since 2008. It requires the re-construction of traditional power systems. As an important component of a smart grid, load management has been diffusely known as a bright solution to enhance the demand side energy efficiency and optimize energy consumption. In this project, load management techniques on the demand side are studied at two levels in a smart grid: the smart home level and the load aggregator level. At the smart home level, this project studies the development of home energy management systems (HEMSs), which optimally schedule home energy resources to minimize home electricity costs. The potential of plug-in electric vehicles (EVs) is harnessed by the developed HEMS to supply power to the home and absorb surplus residential renewable power output. At the load aggregator level, this project studies the feasibility of aggregating thermostatically controlled loads (TCLs) in multiple buildings to bid in the wholesale power market. An optimal scheduling model for TCLs is proposed in this project to minimize imbalance costs of the load aggregators in the power market. To address the uncertainties in imbalance penalty prices, this project introduces the rolling horizon optimization (RHO) technique to continuously update TCL ON/OFF plans with the realization of imbalance prices. This research also includes techniques for solving load management optimization models. A new heuristic optimization method, Natural Aggregation Algorithm (NAA), is used to solve the aforementioned HEMSs and TCLs scheduling models. The encoding scheme and constraint handling strategies are studied, and the efficiency of NAA in solving the models is also investigated.

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14

Wang, Yuchang. "Decision-making techniques for smart grid energy management." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/28970.

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This thesis has contributed to the design of suitable decision-making techniques for energy management in the smart grid with emphasis on energy efficiency and uncertainty analysis in two smart grid applications. First, an energy trading model among distributed microgrids (MG) is investigated, aiming to improve energy efficiency by forming coalitions to allow local power transfer within each coalition. Then, a more specific scenario is considered that is how to optimally schedule Electric Vehicles (EV) charging in a MG-like charging station, aiming to match as many as EV charging requirements with the uncertain solar energy generation. The solutions proposed in this thesis can give optimal coalition formation patterns for reduced power losses and achieve optimal performance for the charging station. First, several algorithms based on game theory are investigated for the coalition formation of distributed MGs to alleviate the power losses dissipated on the cables due to power transfer. The seller and buyer MGs can make distributed decisions whether to form a coalition with others for energy trading. The simulation results show that game theory based methods that enable cooperation yield a better performance in terms of lower power losses than a non-cooperative approach. This is because by forming local coalitions, power is transferred within a shorter distance and at a lower voltage. Thus, the power losses dissipated on the transmission lines and caused by power conversion at the transformer are both reduced. However, the merge-and-split based cooperative games have an inherent high computational complexity for a large number of players. Then, an efficient framework is established for the power loss minimization problem as a college admissions game that has a much lower computational complexity than the merge-and-split based cooperative games. The seller and buyer MGs take the role of colleges and students in turn and apply for a place in the opposite set following their preference lists and the college MGs’ energy quotas. The simulation results show that the proposed framework demonstrates a comparable power losses reduction to the merge-and-split based algorithms, but runs 700 and 18000 times faster for a network of 10 MGs and 20 MGs, respectively. Finally, the problem of EV charging using various energy sources is studied along with their impact on the charging station’s performance. A multiplier k is introduced to measure the effect of solar prediction uncertainty on the decision-making process of the station. A composite performance index (the Figure of Merit, FoM) is also developed to measure the charging station’s utility, EV users charging requirements and the penalties for turning away new arrivals and for missing charging deadlines. A two-stage admission and scheduling mechanism is further proposed to find the optimal trade-off between accepting EVs and missing charging deadlines by determining the best value of the parameter k under various energy supply scenarios. The numerical evaluations give the solution to the optimization problem and show that some of the key factors such as shorter and longer deadline urgencies of EVs charging requirements, stronger uncertainty of the prediction error, storage capacity and its initial state will not affect significantly the optimal value of the parameter k.

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15

Ge, Rong. "Theories and Techniques for Efficient High-End Computing." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/28863.

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Today, power consumption costs supercomputer centers millions of dollars annually and the heat produced can reduce system reliability and availability. Achieving high performance while reducing power consumption is challenging since power and performance are inextricably interwoven; reducing power often results in degradation in performance. This thesis aims to address these challenges by providing theories, techniques, and tools to 1) accurately predict performance and improve it in systems with advanced hierarchical memories, 2) understand and evaluate power and its impacts on performance, 3) control power and performance for maximum efficiency. Our theories, techniques, and tools have been applied to high-end computing systems. Our theroetical models can improve algorithm performance by up to 59% and accurately predict the impacts of power on performance. Our techniques can evaluate power consumption of high-end computing systems and their applications with fine granularity and save up to 36% energy with little performance degradation.
Ph. D.

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16

Žák, Jaromír. "Návrh a optimalizace senzorických systémů využívajících malovýkonových napájecích generátorů." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-234527.

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Dissertation thesis is focused on using alternative energy sources called energy harvesting. This thesis offers a solution to problems with autonomous powering of sensor networks if primary power source recovery is impossible. In these cases, energy of the external power (e.g. temperature, light, motion) should be used. Proposed solution should be especially used in the field of medical applications (e.g. cochlear implants, pacemakers, insulin pumps). Long time monitoring of the personal health status is also possible when employing automated sensor systems. In this work, there is state of art review relating to the low power energy sources for an alternative powering of sensor systems. It was observed that existing systems are almost prepared for the implementation of energy harvesting power sources. The energy harvesting power sources have been developed by numerous researcher teams around the world, but there are only a few variants of power management circuits for effective energy gaining, storing and using. This area has a huge potential for the next research. The issues regarding to the distribution of gained energy are solved on the complex level in the thesis. For these purposes, a new simulation model of the whole system (fully implantable artificial cochlea) including its subcircuits was developed in the SPICE environment. It connects independent subcircuits into a single comprehensive model. Using this model, a few novel principles for energy distribution (e.g. Charge Push Through technique) was developed. In the near future, these techniques are also applicable to the design of versatile sensor systems.

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17

Ng, Chik-wai, and 吳植偉. "Design techniques of advanced CMOS building blocks for high-performance power management integrated circuits." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B45896926.

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18

Dolan, Michael James. "The application and assessment of active network management techniques for distribution network power flows." Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=17815.

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Анотація:

The UK Government regards renewable energy technology deployment to be crucial in successfully meeting reduced greenhouse gas emission targets. As such, incentives promoting the connection of clean energy sources to the UK's electricity infrastructure are influencing a significant increase of distributed generation (DG) planning applications. With an abundance of the UK's indigenous energy resources being either rural or coastal large volumes of DG are seeking connection at the lower voltage distribution networks. Connecting large quantities of intermittent generation, to distribution networks, presents significant problems to the planning and operation of these traditionally passive networks due to bi-directional power flows creating voltage fluctuations and uncertainty in power flow magnitudes. In addition, conventional planning methods results in financial barriers that are preventing DG connections due to the high cost of reinforcing the existing infrastructure. One method of avoiding, or at least deferring, this high capital costs is to adopt an Active Network Management (ANM) approach. This thesis presents and evaluates two novel ANM approaches that manage the real power output of multiple DG units, in real-time, such that distribution networks operate within thermal limits. Studies are conducted in a closed-loop simulation environment, with actual hardware, on two topologically different networks to demonstrate the flexibility of the novel application of the Optimal Power Flow (OPF) and the Constraint Satisfaction Problem (CSP) when applied to the Power Flow Management (PFM) problem. The performance of these model-based algorithms is assessed against their ability to detect thermal excursions, their solution computation time, their resilience to measurement error, their real power curtailment, their ability to conform to current DG commercial connection agreements and their ability to adapt to changes in network topology. Results reported in this thesis demonstrate the feasibility of these novel ANM approaches for PFM, and their applicability in terms of incorporating intelligence into the UK's future smart grids.

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19

Shao, Hui. "System design and power management for ultra low energy applications using energy harvesting techniques /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20SHAO.

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20

Singh, Manmeet. "Switching Power Converter Techniques for Server and Mobile Applications." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu159486698396321.

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21

Mallangi, Siva Sai Reddy. "Low-Power Policies Based on DVFS for the MUSEIC v2 System-on-Chip." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-229443.

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Анотація:

Multi functional health monitoring wearable devices are quite prominent these days. Usually these devices are battery-operated and consequently are limited by their battery life (from few hours to a few weeks depending on the application). Of late, it was realized that these devices, which are currently being operated at fixed voltage and frequency, are capable of operating at multiple voltages and frequencies. By switching these voltages and frequencies to lower values based upon power requirements, these devices can achieve tremendous benefits in the form of energy savings. Dynamic Voltage and Frequency Scaling (DVFS) techniques have proven to be handy in this situation for an efficient trade-off between energy and timely behavior. Within imec, wearable devices make use of the indigenously developed MUSEIC v2 (Multi Sensor Integrated circuit version 2.0). This system is optimized for efficient and accurate collection, processing, and transfer of data from multiple (health) sensors. MUSEIC v2 has limited means in controlling the voltage and frequency dynamically. In this thesis we explore how traditional DVFS techniques can be applied to the MUSEIC v2. Experiments were conducted to find out the optimum power modes to efficiently operate and also to scale up-down the supply voltage and frequency. Considering the overhead caused when switching voltage and frequency, transition analysis was also done. Real-time and non real-time benchmarks were implemented based on these techniques and their performance results were obtained and analyzed. In this process, several state of the art scheduling algorithms and scaling techniques were reviewed in identifying a suitable technique. Using our proposed scaling technique implementation, we have achieved 86.95% power reduction in average, in contrast to the conventional way of the MUSEIC v2 chip’s processor operating at a fixed voltage and frequency. Techniques that include light sleep and deep sleep mode were also studied and implemented, which tested the system’s capability in accommodating Dynamic Power Management (DPM) techniques that can achieve greater benefits. A novel approach for implementing the deep sleep mechanism was also proposed and found that it can obtain up to 71.54% power savings, when compared to a traditional way of executing deep sleep mode.
Nuförtiden så har multifunktionella bärbara hälsoenheter fått en betydande roll. Dessa enheter drivs vanligtvis av batterier och är därför begränsade av batteritiden (från ett par timmar till ett par veckor beroende på tillämpningen). På senaste tiden har det framkommit att dessa enheter som används vid en fast spänning och frekvens kan användas vid flera spänningar och frekvenser. Genom att byta till lägre spänning och frekvens på grund av effektbehov så kan enheterna få enorma fördelar när det kommer till energibesparing. Dynamisk skalning av spänning och frekvens-tekniker (såkallad Dynamic Voltage and Frequency Scaling, DVFS) har visat sig vara användbara i detta sammanhang för en effektiv avvägning mellan energi och beteende. Hos Imec så använder sig bärbara enheter av den internt utvecklade MUSEIC v2 (Multi Sensor Integrated circuit version 2.0). Systemet är optimerat för effektiv och korrekt insamling, bearbetning och överföring av data från flera (hälso) sensorer. MUSEIC v2 har begränsad möjlighet att styra spänningen och frekvensen dynamiskt. I detta examensarbete undersöker vi hur traditionella DVFS-tekniker kan appliceras på MUSEIC v2. Experiment utfördes för att ta reda på de optimala effektlägena och för att effektivt kunna styra och även skala upp matningsspänningen och frekvensen. Eftersom att ”overhead” skapades vid växling av spänning och frekvens gjordes också en övergångsanalys. Realtidsoch icke-realtidskalkyler genomfördes baserat på dessa tekniker och resultaten sammanställdes och analyserades. I denna process granskades flera toppmoderna schemaläggningsalgoritmer och skalningstekniker för att hitta en lämplig teknik. Genom att använda vår föreslagna skalningsteknikimplementering har vi uppnått 86,95% effektreduktion i jämförelse med det konventionella sättet att MUSEIC v2-chipets processor arbetar med en fast spänning och frekvens. Tekniker som inkluderar lätt sömn och djupt sömnläge studerades och implementerades, vilket testade systemets förmåga att tillgodose DPM-tekniker (Dynamic Power Management) som kan uppnå ännu större fördelar. En ny metod för att genomföra den djupa sömnmekanismen föreslogs också och enligt erhållna resultat så kan den ge upp till 71,54% lägre energiförbrukning jämfört med det traditionella sättet att implementera djupt sömnläge.

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22

Robertson, James George. "New optimal power flow techniques to improve integration of distributed generation in responsive distribution networks." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/10528.

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Climate change has brought about legally-binding targets for Scotland, the U.K. and the E.U. to reduce greenhouse gas emissions and source a share of overall energy consumption from renewable energy resources by 2020. With severe limitations in the transport and heating sectors the onus is on the electricity sector to provide a significant reduction in greenhouse gas emissions and introduce a substantial increase in renewable energy production. The most attractive renewable energy resources are located in the geographic extremes of the country, far from the large population densities and high voltage, high capacity transmission networks. This means that the majority of renewable generation technologies will need to connect to the conventionally passive, lower voltage distribution networks. The integration of Distributed Generation (DG) is severely restricted by the technical limitations of the passively managed lower voltage infrastructure. Long lead times and the capital expenditure of traditional electricity network reinforcement can significantly delay or make the economics of some renewable generation schemes unviable. To be able to quickly and cost-effectively integrate significant levels of DG, the conventional fit-and-forget approach will have to be evolved into a ‘connect-and-manage’ system using active network management (ANM) techniques. ANM considers the real-time variation in generation and demand levels and schedules electricity network control settings to alleviate system constraints and increase connectable capacity of DG. This thesis explores the extent to which real time adjustments to DG and network asset controller set-points could allow existing networks to accommodate more DG. This thesis investigates the use of a full AC OPF technique to operate and schedule in real time variables of ANM control in distribution networks. These include; DG real and reactive power output and on-load-tap-changing transformer set-points. New formulations of the full AC OPF problem including multi-objective functions, penalising unnecessary deviation of variable control settings, and a Receding-Horizon formulation are assessed. This thesis also presents a methodology and modelling environment to explore the new and innovative formulations of OPF and to assess the interactions of various control practices in real time. Continuous time sequential, single scenario, OPF analyses at a very short control cycle can lead to the discontinuous and unnecessary switching of network control set-points, particularly during the less onerous network operating conditions. Furthermore, residual current flow and voltage variation can also gave rise to undesirable network effects including over and under voltage excursion and thermal overloading of network components. For the majority of instances, the magnitude of constraint violation was not significant but the levels of occurrence gave occasional cause for concern. The new formulations of the OPF problem were successful in deterring any extreme and unsatisfactory effects. Results have shown significant improvements in the energy yield from non-firm renewable energy resources. Initial testing of the real time OPF techniques in a simple demonstration network where voltage rise restricted the headroom for installed DG capacity and energy yield, showed that the energy yield for a single DG increased by 200% from the fit-and-forget scenario. Extrapolation of the OPF technique to a network with multiple DGs from different types of renewable energy resources showed an increase of 216% from the fit-and-forget energy yield. In a much larger network case study, where thermal loading limits constrained further DG capacity and energy yield, the increase in energy yield was more modest with an average increase of 45% over the fit-and-forget approach. In the large network where thermal overloading prevailed there was no immediate alternative to real power curtailment. This work has demonstrated that the proposed ANM OPF schemes can provide an intelligent, more cost effective and quicker alternative to network upgrades. As a result, DNOs can have a better knowledge and understanding of the capabilities and technical limitations of their networks to absorb DG safely and securely, without the expense of conventional network reinforcement.

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23

Gopalakrishnan, Chandramouli. "High Level Techniques for Leakage Power Estimation andOptimization in VLSI ASICs." Scholar Commons, 2003. https://scholarcommons.usf.edu/etd/1376.

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As technology scales down and CMOS circuits are powered by lower supply voltages, standby leakage current becomes significant. A behavioral level framework for the synthesis of data-paths with low leakage power is presented. There has been minimal work done on the behavioral synthesis of low leakage datapaths. We present a fast architectural simulator for leakage (FASL) to estimate the leakage power dissipated by a system described hierarchically in VHDL. FASL uses a leakage power model embedded into VHDL leafcells. These leafcells are characterized for leakage accurately using HSPICE. We present results which show that FASL measures leakage power significantly faster than HSPICE, with less than a 5% loss in accuracy, compared to HSPICE. We present a comprehensive framework for synthesizing low leakage power data-paths using a parameterized Multi-threshold CMOS (MTCMOS) component library. The component library has been characterized for leakage power and delay as a function of sleep transistor width. We propose four techniques for minimization of leakage power during behavioral synthesis: (1) leakage power management using MTCMOS modules; (2) an allocation and binding algorithm for low leakage based on clique partitioning; (3) selective binding to MTCMOS technology, allowing the designer to have control over the area overhead; and (4) a performance recovery technique based on multi-cycling and introduction of slack, to alleviate the loss in performance attributed to the introduction of MTCMOS modules in the data-path. Finally, we propose two iterative search based techniques, based on Tabu search, to synthesize low leakage data-paths. The first technique searches for low leakage scheduling options. The second technique simultaneously searches for a low leakage schedule and binding. It is shown that the latter technique of unified search is more robust. The quality of results generated bytabu-based technique are superior to those generated by simulated annealing (SA) search technique.

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24

Adhinarayanan, Vignesh. "Models and Techniques for Green High-Performance Computing." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/98660.

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High-performance computing (HPC) systems have become power limited. For instance, the U.S. Department of Energy set a power envelope of 20MW in 2008 for the first exascale supercomputer now expected to arrive in 2021--22. Toward this end, we seek to improve the greenness of HPC systems by improving their performance per watt at the allocated power budget. In this dissertation, we develop a series of models and techniques to manage power at micro-, meso-, and macro-levels of the system hierarchy, specifically addressing data movement and heterogeneity. We target the chip interconnect at the micro-level, heterogeneous nodes at the meso-level, and a supercomputing cluster at the macro-level. Overall, our goal is to improve the greenness of HPC systems by intelligently managing power. The first part of this dissertation focuses on measurement and modeling problems for power. First, we study how to infer chip-interconnect power by observing the system-wide power consumption. Our proposal is to design a novel micro-benchmarking methodology based on data-movement distance by which we can properly isolate the chip interconnect and measure its power. Next, we study how to develop software power meters to monitor a GPU's power consumption at runtime. Our proposal is to adapt performance counter-based models for their use at runtime via a combination of heuristics, statistical techniques, and application-specific knowledge. In the second part of this dissertation, we focus on managing power. First, we propose to reduce the chip-interconnect power by proactively managing its dynamic voltage and frequency (DVFS) state. Toward this end, we develop a novel phase predictor that uses approximate pattern matching to forecast future requirements and in turn, proactively manage power. Second, we study the problem of applying a power cap to a heterogeneous node. Our proposal proactively manages the GPU power using phase prediction and a DVFS power model but reactively manages the CPU. The resulting hybrid approach can take advantage of the differences in the capabilities of the two devices. Third, we study how in-situ techniques can be applied to improve the greenness of HPC clusters. Overall, in our dissertation, we demonstrate that it is possible to infer power consumption of real hardware components without directly measuring them, using the chip interconnect and GPU as examples. We also demonstrate that it is possible to build models of sufficient accuracy and apply them for intelligently managing power at many levels of the system hierarchy.
Doctor of Philosophy
Past research in green high-performance computing (HPC) mostly focused on managing the power consumed by general-purpose processors, known as central processing units (CPUs) and to a lesser extent, memory. In this dissertation, we study two increasingly important components: interconnects (predominantly focused on those inside a chip, but not limited to them) and graphics processing units (GPUs). Our contributions in this dissertation include a set of innovative measurement techniques to estimate the power consumed by the target components, statistical and analytical approaches to develop power models and their optimizations, and algorithms to manage power statically and at runtime. Experimental results show that it is possible to build models of sufficient accuracy and apply them for intelligently managing power on multiple levels of the system hierarchy: chip interconnect at the micro-level, heterogeneous nodes at the meso-level, and a supercomputing cluster at the macro-level.

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25

Bass, Jeremy Hugh. "The potential of combined heat and power generation, wind power generation and load management techniques for cost reduction in small electricity supply systems." Thesis, University of Strathclyde, 1987. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21484.

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An evaluation is made of the potential fuel and financial savings possible when a small, autonomous diesel system sized to meet the demands of an individual, domestic consumer is adapted to include: (1) combined heat and power (CUP) generation. (2) wind turbine generation. (3) direct load control. The potential of these three areas is investigated by means of time-step simulation modelling on a microcomputer. Models are used to evaluate performance and a Net Present Value analysis used to assess costs. A cost/benefit analysis then enables those areas, or combination of areas, that facilitate the greatest savings to be identified. The modelling work is supported by experience gained from the following: (1) field study of the Lundy Island wind/diesel system. (2) laboratory testing of a small diesel generator set. (3) study of a diesel based CUP unit. (4) study of a diesel based direct load control system. (5) statistical analysis of data obtained from the long-term monitoring of a large number of individual household's electricity consumption. Rather than consider the consumer's electrical demand in isolation, a more flexible approach is adopted, with consumer demand being regarded as the sum of primarily two components: a small, electricity demand for essential services and a large, reschedulable demand for heating/cooling. The results of the study indicate that: (1) operating a diesel set in a CUP mode is the best strategy for both financial and fuel savings. A simple retrofit enables overall conversion efficiencies to be increased from 25% to 60%, or greater, at little cost. (2) wind turbine generation in association with direct load control is a most effective combination. (3) A combination of both the above areas enables greatest overall financial savings, in favourable winds resulting in unit energy costs around 20% of those of diesel only operation.

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26

Seelhof, Michael. "Long term infrastructure investments under uncertainty in the electric power sector using approximate dynamic programming techniques." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90724.

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Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 179-183).
A computer model was developed to find optimal long-term investment strategies for the electric power sector under uncertainty with respect to future regulatory regimes and market conditions. The model is based on a multi-stage problem formulation and uses approximate dynamic programming techniques to find an optimal solution. The model was tested under various scenarios. The model results were analyzed with regards to the optimal first-stage investment decision, the final technology mix, total costs, the cost of ignoring uncertainty and the cost of regulatory uncertainty.
by Michael Seelhof.
S.M. in Engineering and Management

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27

Ghosh, Mrinmoy. "Microarchitectural techniques to reduce energy consumption in the memory hierarchy." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28265.

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Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Lee, Hsien-Hsin S.; Committee Member: Cahtterjee,Abhijit; Committee Member: Mukhopadhyay, Saibal; Committee Member: Pande, Santosh; Committee Member: Yalamanchili, Sudhakar.

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28

Tegen, Suzanne Isabel Helmholz. "Electricity decision-making: New techniques for calculating statewide economic impacts from new power supply and demand-side management programs." Diss., Connect to online resource, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3239449.

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29

García, Elvira David. "Contributions on DC microgrid supervision and control strategies for efficiency optimization through battery modeling, management, and balancing techniques." Doctoral thesis, Universitat Rovira i Virgili, 2021. http://hdl.handle.net/10803/672010.

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Aquesta tesi presenta equips, models i estratègies de control que han estat desenvolupats amb l'objectiu final de millorar el funcionament d'una microxarxa CC. Es proposen dues estratègies de control per a millorar l'eficiència dels convertidors CC-CC que interconnecten les unitats de potència de la microxarxa amb el bus CC. La primera estratègia, Control d'Optimització de Tensió de Bus centralitzat, administra la potència del Sistema d'Emmagatzematge d'Energia en Bateries de la microxarxa per aconseguir que la tensió del bus segueixi la referència dinàmica de tensió òptima que minimitza les pèrdues dels convertidors. La segona, Optimització en Temps Real de la Freqüència de Commutació, consisteix a operar localment cada convertidor a la seva freqüència de commutació òptima, minimitzant les seves pèrdues. A més, es proposa una nova topologia d'equilibrador actiu de bateries mitjançant un únic convertidor CC-CC i s'ha dissenyat la seva estratègia de control. El convertidor CC-CC transfereix càrrega cel·la a cel·la, emprant encaminament de potència a través d'un sistema d'interruptors controlats. L'estratègia de control de l'equalitzador aconsegueix un ràpid equilibrat del SOC evitant sobrecompensar el desequilibri. Finalment, es proposa un model simple de degradació d'una cel·la NMC amb elèctrode negatiu de grafit. El model combina la simplicitat d'un model de circuit equivalent, que explica la dinàmica ràpida de la cel·la, amb un model físic del creixement de la capa Interfase Sòlid-Electròlit (SEI), que prediu la pèrdua de capacitat i l'augment de la resistència interna a llarg termini. El model proposat quantifica la incorporació de liti al rang de liti ciclable necessària per a aconseguir els límits de OCV després de la pèrdua de liti ciclable en la reacció secundària. El model de degradació SEI pot emprar-se per a realitzar un control predictiu de bateries orientat a estendre la seva vida útil.
Aquesta tesi presenta equips, models i estratègies de control que han estat desenvolupats amb l'objectiu final de millorar el funcionament d'una microxarxa CC. Es proposen dues estratègies de control per a millorar l'eficiència dels convertidors CC-CC que interconnecten les unitats de potència de la microxarxa amb el bus CC. La primera estratègia, Control d'Optimització de Tensió de Bus centralitzat, administra la potència del Sistema d'Emmagatzematge d'Energia en Bateries de la microxarxa per aconseguir que la tensió del bus segueixi la referència dinàmica de tensió òptima que minimitza les pèrdues dels convertidors. La segona, Optimització en Temps Real de la Freqüència de Commutació, consisteix a operar localment cada convertidor a la seva freqüència de commutació òptima, minimitzant les seves pèrdues. A més, es proposa una nova topologia d'equilibrador actiu de bateries mitjançant un únic convertidor CC-CC i s'ha dissenyat la seva estratègia de control. El convertidor CC-CC transfereix càrrega cel·la a cel·la, emprant encaminament de potència a través d'un sistema d'interruptors controlats. L'estratègia de control de l'equalitzador aconsegueix un ràpid equilibrat del SOC evitant sobrecompensar el desequilibri. Finalment, es proposa un model simple de degradació d'una cel·la NMC amb elèctrode negatiu de grafit. El model combina la simplicitat d'un model de circuit equivalent, que explica la dinàmica ràpida de la cel·la, amb un model físic del creixement de la capa Interfase Sòlid-Electròlit (SEI), que prediu la pèrdua de capacitat i l'augment de la resistència interna a llarg termini. El model proposat quantifica la incorporació de liti al rang de liti ciclable necessària per a aconseguir els límits de OCV després de la pèrdua de liti ciclable en la reacció secundària. El model de degradació SEI pot emprar-se per a realitzar un control predictiu de bateries orientat a estendre la seva vida útil.
This dissertation presents a set of equipment, models and control strategies, that have been developed with the final goal of improving the operation of a DC microgrid. Two control strategies are proposed to improve the efficiency of the DC-DC converters that interface the microgrid’s power units with the DC bus. The first strategy is centralized Bus Voltage Optimization Control, which manages the power of the microgrid’s Battery Energy Storage System to make the bus voltage follow the optimum voltage dynamic reference that minimizes the converters’ losses. The second control strategy is Online Optimization of Switching Frequency, which consists in locally operating each converter at its optimum switching frequency, again minimizing power losses. The two proposed optimization strategies have been validated in simulations. Moreover, a new converter-based active balancing topology has been proposed and its control strategy has been designed. This equalizer topology consists of a single DC-DC converter that performs cell-to-cell charge transfer employing power routing via controlled switches. The control strategy of the equalizer has been designed to achieve rapid SOC balancing while avoiding imbalance overcompensation. Its performance has been validated in simulation. Finally, a simple degradation model of an NMC battery cell with graphite negative electrode is proposed. The model combines the simplicity of an equivalent circuit model, which explains the fast dynamics of the cell, with a physical model of the Solid-Electrolyte Interphase (SEI) layer growth process, which predicts the capacity loss and the internal resistance rise in the long term. The proposed model fine-tunes the capacity loss prediction by accounting for the incorporation of unused lithium reserves of both electrodes into the cyclable lithium range to reach the OCV limits after the side reaction has consumed cyclable lithium. The SEI degradation model can be used to perform predictive control of batteries oriented toward extending their lifetime.

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30

Brka, Adel. "Optimisation of stand-alone hydrogen-based renewable energy systems using intelligent techniques." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2015. https://ro.ecu.edu.au/theses/1756.

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Wind and solar irradiance are promising renewable alternatives to fossil fuels due to their availability and topological advantages for local power generation. However, their intermittent and unpredictable nature limits their integration into energy markets. Fortunately, these disadvantages can be partially overcome by using them in combination with energy storage and back-up units. However, the increased complexity of such systems relative to single energy systems makes an optimal sizing method and appropriate Power Management Strategy (PMS) research priorities. This thesis contributes to the design and integration of stand-alone hybrid renewable energy systems by proposing methodologies to optimise the sizing and operation of hydrogen-based systems. These include using intelligent techniques such as Genetic Algorithm (GA), Particle Swarm Optimisation (PSO) and Neural Networks (NNs). Three design aspects: component sizing, renewables forecasting, and operation coordination, have been investigated. The thesis includes a series of four journal articles. The first article introduced a multi-objective sizing methodology to optimise standalone, hydrogen-based systems using GA. The sizing method was developed to calculate the optimum capacities of system components that underpin appropriate compromise between investment, renewables penetration and environmental footprint. The system reliability was assessed using the Loss of Power Supply Probability (LPSP) for which a novel modification was introduced to account for load losses during transient start-up times for the back-ups. The second article investigated the factors that may influence the accuracy of NNs when applied to forecasting short-term renewable energy. That study involved two NNs: Feedforward, and Radial Basis Function in an investigation of the effect of the type, span and resolution of training data, and the length of training pattern, on shortterm wind speed prediction accuracy. The impact of forecasting error on estimating the available wind power was also evaluated for a commercially available wind turbine. The third article experimentally validated the concept of a NN-based (predictive) PMS. A lab-scale (stand-alone) hybrid energy system, which consisted of: an emulated renewable power source, battery bank, and hydrogen fuel cell coupled with metal hydride storage, satisfied the dynamic load demand. The overall power flow of the constructed system was controlled by a NN-based PMS which was implemented using MATLAB and LabVIEW software. The effects of several control parameters, which are either hardware dependent or affect the predictive algorithm, on system performance was investigated under the predictive PMS, this was benchmarked against a rulebased (non-intelligent) strategy. The fourth article investigated the potential impact of NN-based PMS on the economic and operational characteristics of such hybrid systems. That study benchmarked a rule-based PMS to its (predictive) counterpart. In addition, the effect of real-time fuel cell optimisation using PSO, when applied in the context of predictive PMS was also investigated. The comparative analysis was based on deriving the cost of energy, life cycle emissions, renewables penetration, and duty cycles of fuel cell and electrolyser units. The effects of other parameters such the LPSP level, prediction accuracy were also investigated. The developed techniques outperformed traditional approaches by drawing upon complex artificial intelligence models. The research could underpin cost-effective, reliable power supplies to remote communities as well as reducing the dependence on fossil fuels and the associated environmental footprint.

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31

Kingry, Nathaniel. "Heuristic Optimization and Sensing Techniques for Mission Planning of Solar-Powered Unmanned Ground Vehicles." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1523874767812408.

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32

Emelin, Samuel. "Analyse et intercomparaison des choix techniques majeurs en terme de structures de réseau et de règles d'exploitation parmi les grands distributeurs d'électricité." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT042.

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Confronté à un contexte de stagnation globale de la consommation d'électricité mais avec un potentiel important de développement de nouveaux usages, ainsi qu'à l'apparition d'unités de production dispersée sur le territoire, le principal gestionnaire de réseau de distribution français a besoin d'expliciter ce que sont ses grands choix de structure et de règles d'exploitation, et de les comparer avec les distributeurs étrangers. Les principes de construction du réseau ont un impact sur la capacité à intégrer les nouvelles installations de consommation ou de production à moindre cout, et à assurer les exigences sociétales,notamment pour ce qui concerne la continuité de fourniture. Cette thèse permet de comparer ces choix techniques majeurs avec les pratiques rencontrées à l'étranger, pour situer le réseau français et ses spécificités dans un environnement technique international.Après avoir arrêté une perspective de développement des usages et des productions en France sur la base notamment des textes législatifs, l'architecture du réseau de distribution français est décrite. Les différences fonctionnelles de choix de structure dans le monde sont alors analysés, en soulignant les conséquences dans le dimensionnement par rapport au cas français. Puis l'équilibre entre niveaux de tension est questionné, ainsi que les effet des caractéristiques du territoire sur le réseau. Enfin, des choix techniques nouveaux sont proposés après analyse des points forts et des points faibles des variantes existant dans le monde
Faced to a context of a global lack of growth in electricity consumption, but with many potential development of new uses, added with the appearance of more and more dispersed generation, the main French distribution grid utility needs to question and compare its choicesconcerning grid structure and exploitation practices. Grid building principles have a greatimpact over its capacity to integrate at low cost consumption and production facilities, whilemeeting society needs, mainly continuity of supply. This work allows to compare thosetechnical choices between France and other countries, to determine where French utilitystands and what are its specific features in a worldwide technical environment.After setting a perspective about uses and production development, mainly on the basis of French legislation, the overall distribution grid architecture is described. Functional differences in structure choices in the world are then analysed, their consequences in thesizing of equipments is underlined. Then the equilibrium between voltage levels is questioned,as the effect of territorial features on the grid. Finally, new technical choices are proposed after advantages and drawbacks analysis of existing world grids

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33

Ouni, Bassem. "Caractérisation, modélisation et estimation de la consommation d'énergie à haut-niveau des OS embarqués." Phd thesis, Université Nice Sophia Antipolis, 2013. http://tel.archives-ouvertes.fr/tel-01059814.

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La consommation énergétique est devenue un problème majeur dans la conception des systèmes aussi bien d'un point de vue de la fiabilité des circuits que de l'autonomie d'un équipement embarqué. Cette thèse vise à caractériser et modéliser le coût énergétique du système d'exploitation (OS) embarqué en vue d'explorer des solutions faibles consommation. La première contribution consiste à définir une approche globale de modélisation de la consommation des services de base de l'OS: la stimulation de l'exécution de ces services, tels que le changement de contexte, l'ordonnancement et la communication interprocessus, est effectuée à travers des programmes de test adéquats. Sur la base de mesures de la consommation d'énergie sur la carte OMAP35x EVM, des paramètres pertinents soit matériels soit logiciels ont été identifiés pour en déduire des modèles de consommation. Dans une seconde étape, la prise en compte de ces paramètres doit intervenir au plus haut niveau de la conception. L'objectif sera d'exploiter les fonctionnalités offertes par un langage de modélisation et d'analyse architecturale AADL tout en modélisant les aspects logiciel et matériel en vue d'estimer la consommation d'énergie. Ensuite, les modèles énergétiques de l'OS ont été intégrés dans un simulateur multiprocesseur de politique d'ordonnancement STORM afin d'identifier la consommation de l'OS et ceci pour des politiques d'ordonnancement mettant en œuvre des techniques de réduction de la consommation tel que le DVFS et le DPM. Enfin, la définition et vérification de certaines contraintes temps-réel et énergétiques ont été effectuées avec des langages de spécification de contraintes (QAML, RDAL).

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34

Chen, Jhih-jie, and 陳志杰. "A Novel Power Management Technique Applied in Non- Contact Vital Sign Detection System." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/63024919434872874457.

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Анотація:

碩士
國立中山大學
電機工程學系研究所
100
This paper presents a novel power management analysis method to reduce the power consumption for the non-contact vital sign sensor. The sensor consisting of the class-E power amplifier (PA), low noise amplifier (LNA), single pole double through (SPDT) switch, and circularly polarized antenna (CPA) is integrated on the Flame Retardant Class 4 (FR-4) epoxy-glass laminate substrate. The appropriate pulse width and pulse period are determined to decrease the power consumption and accurately detect the human physiological signals (respiration and heartbeat). A simple direct down-conversion architecture with a tunable phase shifter is utilized to eliminate the null detection point and the direct current (DC) offset. The overall power consumption of the proposed sensor with the novel power management technique is only 40 % of the conventional system with the DC bias, which can be utilized for the green energy application.

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35

Chen, Yu-Her, and 陳禹何. "Novel Transceiver Structure with Power Management Technique by Dynamic Supply for Non-contact Vital Sign Detection." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/12994374572764499245.

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Анотація:

碩士
國立中山大學
通訊工程研究所
100
The power management technique is employed in the direct down-conversion non-quadrature microwave Doppler radar transceiver for the non-contact vital sign detection based on 0.18 µm CMOS technology. The overshoot and undershoot types of the transient waveform distortion and the simultaneous switching noise (SSN) caused by the high speed pulse signal will severely influence the accuracy for the vital sign detection, so that this investigation clearly analyzes the pulse period, pulse width, rise/fall times and the voltage levels of the pulse bias. In the circuit design, the low power current-reused (CRU) power amplifier (PA) can maintain enough output power by using the crucial double primary transformer (DPTF) and balun. The presented LNA with a differential inductor can provide the noise matching needed and increase the transducer gain in order to achieve the optimal power consumption and the transducer gain in the Rx mode. The excellent isolation between the Tx and Rx mode is obtained with the new parallel directed switch. The overall power consumption of the presented transceiver with the optimal pulse bias is 60% lower than the conventional transceiver with the direct current (DC) bias, and the null detection point and DC offset can be eliminated by the tunable phase shifter.

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36

Paracha, Zahir Javed. "Design and development of intelligent computational techniques for power quality data monitoring and management." Thesis, 2011. https://vuir.vu.edu.au/19381/.

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The most important requirement of power system operations is sustained availability and quality supply of electric power. In Electrical Power Distribution System (EPDS), non-linear loads are the main cause of power quality (PQ) degradation. The PQ problems generated by these non-linear loads are complex and diversified in nature. The power system which is not capable to handle non-linear loads faces the problem of voltage unbalance, sag, swell, momentary or temporary interruption and ultimately complete outage of EPDS. The PQ problems have motivated power system engineers to design and develop new methodologies and techniques to enhance EPDS performance. To do so, they are required to analyse the PQ data of the system under consideration. Since, the density of the monitoring nodes in EPDS is quite high, the aggregate analysis is computationally involved. In addition, the cost involved with the PQ shortcomings is significantly high (for domestic consumers and rises exponentially for industrial consumers), hence it also becomes mandatory to project /predict the undesired PQ disturbance in EPDS. This will provides power system engineers to formulate intelligent strategy for efficient power system operations. This objective of the research is to identify and exploit the hidden correlation in PQ data with minimal computational cost and further use this knowledge to classify any PQ disturbance that may occur. ... Further this research also investigates the power distribution system behaviour considering the relationship of main PQ disturbance harmonics in conjunction with the other major PQ parameters i.e. voltage unbalance, sag, swell and frequency.

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37

Musti, S. S. Phaniram. "Development Of Algorithms For Bad Data Detection In Power System State Estimation." Thesis, 2007. http://hdl.handle.net/2005/496.

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Power system state estimation (PSSE) is an energy management system function responsible for the computation of the most likely values of state variables viz., bus voltage magnitudes and angles. The state estimation is obtained within a network at a given instant by solving a system of mostly non-linear equations whose parameters are the redundant measurements, both static such as transformer/line parameters and dynamic such as, status of circuit breakers/isolators, transformer tap positions, active/reactive power flows, generator active/reactive power outputs etc. PSSE involves solving an over determined set of nonlinear equations by minimizing a weighted norm of the measurement residuals. Typically, the L1 and L2 norms are employed. The use of L2 norm leads to state estimation based on the weighted least squares (WLS) criterion. This method is known to exhibit efficient filtering capability when the errors are Gaussian but fails in the case of presence of bad data. The method of hypothesis testing identification can be incorporated into the WLS estimator to detect and identify bad data. Nevertheless, it is prone to failure when the measurement is a leverage point. On the other hand state estimation based on the weighted least absolute value (WLAV) criterion using L1 norm, has superior bad data suppression capability. But it also fails in rejecting bad data measurements associated with leverage points. Leverage points are highly influential measurements that attract the state estimator solution towards them. Consequently, much research effort has focused recently, on producing a LAV estimator that remains robust in the presence of bad leverage measurements. This problem has been addressed in the thesis work. Two methods, which aims development of robust estimator that are insensitive to bad leverage points, have been proposed viz., (i) The objective function used here is obtained by linearizing L2 norm of the error function. In addition to the constraints corresponding to measurement set, constraints corresponding to bounds of state variables are also involved. Linear programming (LP) optimization is carried out using upper bound optimization technique. (ii) A hybrid optimization algorithm which is combination of”upper bound optimization technique” and ”an improved algorithm for discrete l1 linear approximation”, to restrict the state variables not to leave the basis during optimization process. Linear programming optimization, with bounds of state variables as additional constraints is carried out using the proposed hybrid optimization algorithm. The proposed state estimator algorithms are tested on 24-bus EHV equivalent of southern power network, 36-bus EHV equivalent of western grid, 205-bus interconnected grid system of southern region and IEEE-39 bus New England system. Performances of the proposed two methods are compared with the WLAV estimator in the presence of bad data associated with leverage points. Also, the effect of bad leverage measurements on the interacting bad data, which are non-leverage, has been compared. Results show that proposed state estimator algorithms rejects bad data associated with leverage points efficiently.

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38

Lu, Zhijian. "Runtime management techniques for power-and temperature-aware computing/." 2007. http://wwwlib.umi.com/dissertations/fullcit/3248096.

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39

Hsieh, Jing-Rong, and 謝景融. "Centralized Power Management Techniques for Wireless Local Area Networks." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/47288800153547084225.

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Анотація:

博士
國立交通大學
電信工程研究所
99
In the past decade, IEEE 802.11 wireless LANs has gained large popularity in broadband wireless access. Users are demanding high performances while keeping respectable operation time for the mobile devices. Power management (PM) is an essential technique for energy saving by putting de-vices into low power state during appropriate interval. For a multi-user and shared medium wireless network, in addition to managing power state according to readiness of traffic, it is important to separate the usage time of different users to prevent energy-consuming overhearing. Hence, in this dissertation, considering variable-bit-rate traffic and unpredictable error recovery, we focus on the scheduling algorithms to reduce the chance of service period overlapping. To support standardized power saving mechanism in IEEE 802.11e, we propose a feasible scheduling algorithm for the Scheduled Automatic Power Save Delivery. The goal is to maximize the minimum distance between the scheduled instants of new joining traffic stream (TS) and exist-ing scheduled events (SEs). By the proven periodicity of service schedules, the redundant check in the previous brute-force method can be avoided. Moreover, considering limited number of classes for TSs, we can pre-calculate and store necessary information to further reduce the implementation complexity. Extending the idea of finding the optimal service start time for new joining TS incre-mentally, we also study the rearrangement of existing SEs to further maximize the system minimum distance. We prove the upper bound of the system minimum distance and design efficient rearrang-ing algorithms to achieve satisfactory energy saving. In order to achieve higher system bandwidth utilization (BU), multi-polling mechanisms are often employed to reduce protocol overhead. However, they may require wireless stations (STAs) to spend much time in overhearing. We propose an energy-efficient multi-polling mechanism which combines PM strategy with a low overhead Medium Access Control protocol. Given a desirable guarantee of BU, an energy optimized wake-up time schedule (WTS) is devised. Significant saving of energy can be obtained with only small loss of BU as trade-off. It is the consequence of alleviat-ing the overhearing problem by well scheduled WTSs for STAs. In the end, we also study the ener-gy saving issue induced from error recovery. A WTS and a renewal algorithm in correspondence with the delay caused by retransmissions are proposed for the TDMA-like multi-polling mechanism. Simulation results show that, compared with the original setting, significant improvement can be obtained by the proposed algorithms.

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40

Wu, Tung-Yeh. "Power supply noise management : techniques for estimation, detection, and reduction." Thesis, 2010. http://hdl.handle.net/2152/ETD-UT-2010-12-2440.

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Power supply noise has become a critical issue for low power and high performance circuit design in recent years. The rapid scaling of the CMOS process has pushed the limit further and further in building low-cost and increasingly complex digital VLSI systems. Continued technology scaling has contributed to significant improvements in performance, increases in transistor density, and reductions in power consumption. However, smaller feature sizes, higher operation frequencies, and supply voltage reduction make current and future VLSI systems more vulnerable to power supply noise. Therefore, there is a strong demand for strategies to prevent problems caused by power supply noise. Design challenges exist in different design phases to reduce power supply noise. In terms of physical design, careful power distribution design is required, since it directly determines the quality of power stability and the timing integrity. In addition, power management, such as switching mode of the power gating technique, is another major challenge during the circuit design phase. A bad power gating switching strategy may draw an excessive rush current and slow down other active circuitry. After the circuit is implemented, another critical design challenge is to estimate power supply noise. Designers need to be aware of the voltage drop in order to enhance the power distribution network without wasting unnecessary design resources. However, estimating power supply noise is usually difficult, especially finding the circuit activity which induces the maximum supply noise. Blind search may be very time consuming and not effective. At post-silicon test, detecting power supply noise within a chip is also challenging. The visibility of supply noise is low since there is no trivial method to measure it. However, the supply noise measurement result on silicon is critical to debug and to characterize the chip. This dissertation focuses on novel circuit designs and design methodologies to prevent problems resulted from power supply noise in different design phases. First, a supply noise estimation methodology is developed. This methodology systematically searches the circuit activity inducing the maximum voltage drop. Meanwhile, once the circuit activity is found, it is validated through instruction execution. Therefore, the estimated voltage drop is a realistic estimation close to the real phenomenon. Simulation results show that this technique is able to find the circuit activity more efficiently and effectively compared to random simulation. Second, two on-chip power supply noise detectors are designed to improve the visibility of voltage drop during test phase. The first detector facilitates insertion of numerous detectors when there is a need for additional test points, such as a fine-grained power gating design or a circuit with multiple power domains. It focuses on minimizing the area consumption of the existing detector. This detector significantly reduces the area consumption compared to the conventional approach without losing accuracy due to the area minimization. The major goal of designing the second on-chip detector is to achieve self-calibration under process and temperature variations. Simulation and silicon measurement results demonstrate the capability of self-calibration regardless these variations. Lastly, a robust power gating reactivation technique is designed. This reactivation scheme utilizes the on-chip detector presented in this dissertation to monitor power supply noise in real time. It takes a dynamic approach to control the wakeup sequence according to the ambient voltage level. Simulation results demonstrate the ability to prevent the excessive voltage drop while the ambient active circuitry induces a high voltage drop during the wakeup phase. As a result, the fixed design resource, which is used to prevent the voltage emergency, can potentially be reduced by utilizing the dynamic reactivation scheme.
text

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41

Zhong, Guo-wei, and 鐘國維. "Campus Building Power Management Using Embedded System and Software Agent Techniques." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/73563155400006353582.

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Анотація:

碩士
逢甲大學
資訊工程所
98
In recent years, there are less and less resource available on earth. Electricity conserving has been a goal that most people would like to achieve. The electricity consumption of government units, private enterprises, hospitals, and schools are very high. And they try their best to do energy conservation. Classrooms of each building or public areas in the school has many power devices, it’s difficult to do well management. Another reasons is, Campus have many teachers and students, if some of them have bad habits of using power device or waste public power resources, it will cause management difficulties and the waste of electricity. Therefore, this research presents an power management system based on embedded system and software agent techniques. The agents can do power management for every regions by some manage policies which customized by every regions, respectively, implement the power management to every regions in campus building. The agents will also collect the information of the power device using power resources, then do some calculate and make a decision that change manage mode to reduce power consumption mode or not. In embedded systems, the various controller modules and sensor modules are distributed in the regions. By using radio control technology, there will have no trouble in wiring between modules and increasing the number of modules. Finally, for effective monitoring and measurement of large-scale power facilities, the study also included the power analyzer measurement capabilities, it can accurately understand the operation of the power status of equipment, this information will help for the agents to calculate or make a decision.

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42

Song, Ting-Chen Tom. "QoS-based power management techniques for uplink W-CDMA cellular systems." Diss., 2003. http://hdl.handle.net/2263/28078.

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In the past, the design of PC algorithms for CDMA systems has remained at the physical layer to compensate for slow and fast channel impairments (known as fast PC and slow PC). The TDMA/FDMA manages inter-cell interference at the beginning of the radio planning process. In SS technology, real time adaptive PC and power management algorithms would need to work coherently to ensure reliable multi-media services, and the need for this real-time hybrid structure of PC and power management has only been shown recently. The emphasis in this dissertation is therefore on the design of a QoS-based PC structure in W-CDMA applications, the ultimate goal being to evaluate the new QoS-based PC structure by means of a Monte Carlo computer simulation; a multi-user, multimedia W-CDMA simulation package. Before the design of the QoS-based PC structure, this dissertation examines and proposes a new power-sensitive model that addresses factors affecting the W-CDMA system capacity. Consequently, PC problems are put into a framework for various optimization criteria. Finally the design of a QoS-based PC structure by means of Monte Carlo computer simulation is described and evaluate. The first problem is closely related to the fact that W-CDMA is a design of a power management network architecture. The power management can co-exist in every layer of operation with different specific time scale and optimization objectives. The solution to this problem is therefore to introduce a general and mathematically tractable power-sensitive model to identify factors that influence the capacity of W-CDMA cellular systems and then articulate the general power sensitive model to form a PC framework aimed at finding a common systematic treatment for different schools of thought on PC algorithms. This dissertation proves the benefits of layered PC operation for guaranteed QoS transmission and also shows that this research coincides with and extend the literature on PC management by categorizing PC algorithms according to various optimization objectives and time scales. The second problem is to evaluate the new QoS-based PC structure in a channel coded and RAKE combining uplink UMTSIUTRA cellular environment using the Monte Carlo simulation package. The UMTS radio channel models are described in terms of frequency-selective Rayleigh fading: Indoor-Office, Outdoor and Pedestrian and Vehicular environments. The package is simulated in Matlab. The influence of the number of multipath components, of Doppler Spread, the number of received antenna, the coding scheme and multi-access interference are discussed in the dissertation. The performance evaluation criteria for utility-based PC structures are Bit-Error-Rate (BER) performance (robustness), outage performance (tracking ability) and rate of convergence. The first test shows that the new proposed unbalanced step-size closed-loop FPC schemes can provide better SINR tracking ability and better BER performance than conventional balanced step-size PC schemes. The unbalanced FPCs have better PC error distribution in all scenarios. The second test shows that the proposed BER-prediction distributed OPC schemes can provide better BER tracking ability. This scheme converges iteratively to an optimal SINR level under current network settings with no excessive interference to other active users.
Dissertation (M Eng (Electronics))--University of Pretoria, 2006.
Electrical, Electronic and Computer Engineering
Unrestricted

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43

Hankendi, Can. "Adaptive runtime techniques for power and resource management on multi-core systems." Thesis, 2015. https://hdl.handle.net/2144/13682.

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Energy-related costs are among the major contributors to the total cost of ownership of data centers and high-performance computing (HPC) clusters. As a result, future data centers must be energy-efficient to meet the continuously increasing computational demand. Constraining the power consumption of the servers is a widely used approach for managing energy costs and complying with power delivery limitations. In tandem, virtualization has become a common practice, as virtualization reduces hardware and power requirements by enabling consolidation of multiple applications on to a smaller set of physical resources. However, administration and management of data center resources have become more complex due to the growing number of virtualized servers installed in data centers. Therefore, designing autonomous and adaptive energy efficiency approaches is crucial to achieve sustainable and cost-efficient operation in data centers. Many modern data centers running enterprise workloads successfully implement energy efficiency approaches today. However, the nature of multi-threaded applications, which are becoming more common in all computing domains, brings additional design and management challenges. Tackling these challenges requires a deeper understanding of the interactions between the applications and the underlying hardware nodes. Although cluster-level management techniques bring significant benefits, node-level techniques provide more visibility into application characteristics, which can then be used to further improve the overall energy efficiency of the data centers. This thesis proposes adaptive runtime power and resource management techniques on multi-core systems. It demonstrates that taking the multi-threaded workload characteristics into account during management significantly improves the energy efficiency of the server nodes, which are the basic building blocks of data centers. The key distinguishing features of this work are as follows: We implement the proposed runtime techniques on state-of-the-art commodity multi-core servers and show that their energy efficiency can be significantly improved by (1) taking multi-threaded application specific characteristics into account while making resource allocation decisions, (2) accurately tracking dynamically changing power constraints by using low-overhead application-aware runtime techniques, and (3) coordinating dynamic adaptive decisions at various layers of the computing stack, specifically at system and application levels. Our results show that efficient resource distribution under power constraints yields energy savings of up to 24% compared to existing approaches, along with the ability to meet power constraints 98% of the time for a diverse set of multi-threaded applications.

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44

Pan, Chia-peng, and 潘家鵬. "Indoor Devices Power Management by using Embedded System and Software Agent Techniques - A Case Study on the Power Management of Multimedia Classrooms." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/76632045779178169121.

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Анотація:

碩士
逢甲大學
資訊工程所
96
Since the petroleum will be exhausted in tens of years and the oil price will be unavoidably going up, the country does the best to push energy-saving and to reduce carbons activity. The campus is an open space to the public, for a lot of students the insufficient awareness of treasure public resources lead to much waste of the electricity power. Therefore, this research is focused on how to design an agent-based automatic power management system to achieve the goal of energy-saving in the campus. In the past, colleges often adopt the approach of central power management for each building. Users of a classroom usually waste much electricity power because they often forget to turn off power switches or improper use of some heavy power-consumption devices, like air-conditioners, etc. Considering the classroom as the level of power management, however, the college power system manager is unable to take care of each individual classroom because there are so many classrooms. This research proposes an automatic power management system combining the characteristic of conventional central management with the ability of dynamic adjustment of individual management by using embedded system and software agent technology. This thesis proposes a classroom power management system including three main parts: a Classroom Management Server (CM Server), a Power Status Management Card (PSM Card), and a Device Control Card (DC Card). CM Server and PSM Card support the execution of a power management agent system responsible for maintaining school calendar and classroom timetable. A classroom timetable is used for the classroom reservation and task of automatic power management. DC Card is constructed by a micro controller unit responsible for controlling device power switch, detecting the temperature in a classroom and monitoring the existence of human bodies. The experimental system implemented the power management for multimedia classrooms. It controls the indoor devices, which are common in classroom, like light, fan, air-conditioner and even computer. Three kinds of power switch control methods, including relay, infrared ray, and programming control, are proposed. We propose a classroom power management scenario based on Software Agent Technology. A software agent will check for school calendar, and classroom timetable, and classroom usage table to derive a suitable power management scenario. Each power management scenario will perform different management tactic involving some situations, for example if someone in a classroom or not, the environment temperature, and soon. I hope to achieve the goal of reducing school power manager’s pressure in promoting the efficiency of power saving in campus.

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45

Zhao, April (Yang). "Efficiency Enhancement Techniques for Switched Mode Power Electronics." Thesis, 2011. http://hdl.handle.net/1807/29653.

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Анотація:

In the design of the state-of-the-art electronic products, power management circuits play a very important role for the enhancement of overall system efficiency. Switched mode DC-DC converter is an increasingly popular power management circuit due to its superior power conversion efficiency. This thesis introduces two efficiency optimization techniques for switched mode power electronic circuits. One is dead-time optimization. This technique can automatically adjust the dead-time on-the-fly according to the circuit operating conditions. Second, an energy conservation based high-efficiency dimmable multi-channel LED driver is discussed. An auxiliary power switched is use to allow free wheeling of the inductor current during the load disconnect period. The sequential burst mode PWM current sharing scheme with dimming capability can effectively reduce design complexity and cost. The proposed LED driver provides a practical solution for the realization of LED BLU in the flat panel TVs with local dimming capability according to the video content.

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46

Latheef, Mohamed Imran. "Application of optimization techniques for reservoir management in conjunction with thermal power generation." 1991. http://hdl.handle.net/1993/9769.

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47

Chen, Chih-liang, and 陳志良. "Design and Implement a Swing-Vdd Clock-Power Management Techniques in Low-Power Video Decoder for HDTV Applications." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/93310414179258825118.

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Анотація:

碩士
逢甲大學
電子工程所
94
Because the point of designing circuit still mainly focuses on the consuming products, low power design has been extensively researched and been used on various kinds of circuit. Although there is a lot of research about the low power design in recent years, most of low power design technology is very complex for designer. In the thesis, we try to utilize the principle of adiabatic charging to reduce power consumption, find the new low power design structure that can be applied to various kinds of circuit. And then, we will implement and verify the circuit design. We have reached three main goals in this thesis: First of all, we have offered a simple control circuit to produce adiabatic charging signal in power supply; The second, we combine cell-base IC design flow with the swing-Vdd clock-power management circuit and let the designer easy to produce this swing-Vdd clock-power management circuit; Finally, the simulation result of various kinds of circuit prove that the swing-Vdd clock-power management circuit can reduce a lot of power consumption.

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48

Ting, Chung-Yi, and 丁中一. "Power Management Techniques in DC-DC Converters for Low-voltage and High-current Loads." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/k339fp.

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Анотація:

博士
國立臺灣大學
電子工程學研究所
107
Science and technology rapidly progress day by day, such as 5G communication, big data, internet-of-things (IoT), artificial intelligence (AI). In the future, these computers with high-speed computing ability and high-speed data transmission are needed in various applications. Therefore, high-speed integrated circuits are very important in high-speed computing and data transmission interface. In addition, the supply voltage becomes lower and lower because the technology process is rapidly advancement based on Moore’s law. However, power consumption of electronic devices constantly increase for higher performance. Thus, these DC-DC converters in low-voltage and high-current applications are essential research topic in recent years. In low-voltage and high-current applications, these loads have two categories about high-speed digital circuits such as CPUs, GPUs, and AI chips and high-speed analog circuits such as high-speed RF transmitters, high-speed RF receivers, high-speed DACs, high-speed ADCs, and optical communication circuits. In general, these high-speed circuits need to the DC-DC converter with fast load-transient response, low EMI, high-current capability, and high-efficiency. Traditionally, low-dropout regulators (LDOs) have been used in on-chip voltage source because of load-transient response and low-ripple output voltage. However, LDOs are not suitable for high power applications because the dropout voltage leads to low efficiency in low-voltage and high-current applications. To achieve fast load-transient response, fast DVS tracking response, high-current capability, high power efficiency, and low EMI in high power application, the dissertation focuses on studying power management techniques of these DC-DC converters in low-voltage and high-current applications. The dissertation has three works: In the first work, we propose a quasi-V2 hysteretic buck converter with adaptive constant on-time (ACOT) control for fast DVS and load-transient response in RF applications. For implement adaptive constant on-time control, the work proposes adaptive constant on-time circuit with transient-enhanced technique and optimization of system compensation for fast load-transient response and fast DVS. The work uses TSMC T18 1P6M process and chip area is 1.81mm2. The measured peak efficiency is 90.1%. In 600mA step-up/down load current, the light-to-heavy/heavy-to-light recovery time is 0.6μs. In 0.6V voltage step-up/down, the up-tracking/down-tracking time of DVS is 2μs. In the second work, we propose an inductor current-balancing technique (ICBT) for fast-locking delay-locked loop (FL-DLL) based four-phase buck converter with constant on-time control to achieve high-current capability and power efficiency in low-voltage and high-current applications. The work uses quasi-V2 control and constant on-time modulator for transient response and light-load efficiency. Moreover, the work proposes a fast-locking delay-locked loop (FL-DLL) for generating four-phase control signals with phase difference 90 degree and achieving low-ripple output voltage. In FL-DLL, we proposes automatic switching single/dual triggered phase detector (ASS/DT-PD) for achieving fast load-transient response. Furthermore, non-ideal effects of active and passive components causes inductor current in-balance issue. Therefore, the work proposes pulse-width-shrunk technique (PWST) automatically calibrate four-phase control signals to achieve current balance in every phase. The work uses TSMC T18 1P6M process and chip area is 6.17mm2. Finally, these proposed techniques can be verified by post-layout simulation. In 1.4A step-up/down load current, the light-to-heavy/heavy-to-light recovery time is 2.5μs/2.5μs and undershoot/overshoot voltage is below 10mV. Because of achieving current balance and phase alignment, the proposed FL-DLL based four-phase buck converter has 85% efficiency and 4mV voltage ripple. In the third work, we propose a quasi-V2 hysteretic buck converter with EMI reducing technique using phased-locked loop with MASH 1-1 all-digital Δ-Σ modulator. The hysteretic DC-DC buck converter is viewed as voltage control oscillator (VCO). For keeping fixed-frequency, the work uses phase-locked loop to lock PWM frequency. In the EMI reducing technique, phase-locked loop with MASH 1-1 all-digital Δ-Σ modulator randomly modulates PWM control signal for spreading spectrum of output voltage. The chip uses TSMC T18 1P6M process and chip area is 1.81mm2. Moreover, the measured peak efficiency is 90%. By post-layout simulation, the low EMI reducing technique improves 20dB compared with without EMI technique. In load-transient response performance, the light-to-heavy recovery time is 4.47μs and undershoot voltage is 34.3mV and the heavy-to-light recovery time is 5.12μs and overshoot voltage is 32.3mV.

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49

Hsu, Pi-Lin, and 徐碧璘. "The Study of Applying Decision Support System Techniques in Risk Integrated Management for Nuclear Power Plants." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/98260377392435274187.

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Анотація:

碩士
國立中央大學
資訊管理學系
85
This study aims in the application of decision support system technique in risk integrated management for nuclear power plants. Both the Chinese graphic man-machine interface and the fast risk assessment model were developed and integrated. It can help plant personnel get the Probabilistic Risk Assessment (PRA) information more quickly via colorful screen display, and further be applied in monitoring the system operation and maintenance activities. The prototype demonstration system, including one of the plant system implementation, was verified by plant personnel and recommended as an efficient and useful tool in plant safety and performance improvement.

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50

Wu, Kuan-I., and 吳冠儀. "Design and Implementation of the Current-Mode Power Management Integrated Circuits with High Speed Adaptive Controlling Techniques." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/82655247546367713214.

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Анотація:

博士
國立臺灣大學
電子工程學研究所
105
As a result of the continuing growth of miniaturization and integration technologies in the semiconductor industry and the emergence of the internet of things (IoT), the continuing trend is to reduce the power supply voltage to below 1 V and increase the power supply current greatly exceed the 1000 mA per chip. Therefore, the next-generation power management integrated circuits must be able to deal with the challenge of the ultra-low voltage and fast changing load profiles. Since the traditional topology of the current-mode pulse width modulation (PWM) has its bandwidth and stability limitation, the transient response and the power quality cannot be further improved. Therefore, this dissertation is aiming at the high speed adaptive controlling techniques for current-mode PWM converters. In this dissertation, two novel high speed adaptive controlling techniques are proposed. 　　The “synchronous double-pumping (SDP) technique” can dramatically improve the transient response of the conventional current-mode PWM converters. The prototype chip was fabricated using TSMC 0.35 μm CMOS process. The experimental measured recovery time is 2.4 μs and 2.6 μs, respectively, in response to the 400mA step-up and step-down load changes. Those are improved by a factor of 8.33 and 8.23, respectively. 　　The “dynamically adjusted triple-feedback-loop controlling (DATFLC)” technique used an extra dynamic voltage adjusting feedback loop, which is comprising of a variable gain peak current sampler (VGPCS), adaptive load transient accelerator (ALTA) and a dynamic analog voltage elevator (DAVE), to accelerate the transient response of the conventional current-mode PWM converters. Besides, this technique used a transient accelerated zero-current detector (TAZCD) to further accelerate the load step-down response by means of allowing the reversed inductor current to discharge the converter output through the lower gate of the power stage at the beginning periods of the load step-down response. Moreover, the physical implementation of the proposed DATFLC technique is really compact, and the chip area overhead is only 7.41% to the core area. The prototype chip was fabricated using TSMC 0.25 μm HV CMOS process. The experimental measured recovery time is 3.2 μs and 3.0 μs, respectively, in response to the 400mA step-up and step-down load changes. Those are improved by a factor of 7.38 and 8.20, respectively.

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