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1
Bousnane, Kafiha. "Real-time power system dynamic simulation." Thesis, Durham University, 1990. http://etheses.dur.ac.uk/6623/.
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The present day digital computing resources are overburdened by the amount of calculation necessary for power system dynamic simulation. Although the hardware has improved significantly, the expansion of the interconnected systems, and the requirement for more detailed models with frequent solutions have increased the need for simulating these systems in real time. To achieve this, more effort has been devoted to developing and improving the application of numerical methods and computational techniques such as sparsity-directed approaches and network decomposition to power system dynamic studies. This project is a modest contribution towards solving this problem. It consists of applying a very efficient sparsity technique to the power system dynamic simulator under a wide range of events. The method used was first developed by Zollenkopf (^117) Following the structure of the linear equations related to power system dynamic simulator models, the original algorithm which was conceived for scalar calculation has been modified to use sets of 2 * 2 sub-matrices for both the dynamic and algebraic equations. The realisation of real-time simulators also requires the simplification of the power system models and the adoption of a few assumptions such as neglecting short time constants. Most of the network components are simulated. The generating units include synchronous generators and their local controllers, and the simulated network is composed of transmission lines and transformers with tap-changing and phase-shifting, non-linear static loads, shunt compensators and simplified protection. The simulator is capable of handling some of the severe events which occur in power systems such as islanding, island re-synchronisation and generator start-up and shut-down. To avoid the stiffness problem and ensure the numerical stability of the system at long time steps at a reasonable accuracy, the implicit trapezoidal rule is used for discretising the dynamic equations. The algebraisation of differential equations requires an iterative process. Also the non-linear network models are generally better solved by the Newton-Raphson iterative method which has an efficient quadratic rate of convergence. This has favoured the adoption of the simultaneous technique over the classical partitioned method. In this case the algebraised differential equations and the non-linear static equations are solved as one set of algebraic equations. Another way of speeding-up centralised simulators is the adoption of distributed techniques. In this case the simulated networks are subdivided into areas which are computed by a multi-task machine (Perkin Elmer PE3230). A coordinating subprogram is necessary to synchronise and control the computation of the different areas, and perform the overall solution of the system. In addition to this decomposed algorithm the developed technique is also implemented in the parallel simulator running on the Array Processor FPS 5205 attached to a Perkin Elmer PE 3230 minicomputer, and a centralised version run on the host computer. Testing these simulators on three networks under a range of events would allow for the assessment of the algorithm and the selection of the best candidate hardware structure to be used as a dedicated machine to support the dynamic simulator. The results obtained from this dynamic simulator are very impressive. Great speed-up is realised, stable solutions under very severe events are obtained showing the robustness of the system, and accurate long-term results are obtained. Therefore, the present simulator provides a realistic test bed to the Energy Management System. It can also be used for other purposes such as operator training.
2
Demiray, Turhan Hilmi. "Simulation of power system dynamics using dynamic phasor models /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17607.
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Geitner, Gert-Helge, and Guven Komurgoz. "Power Flow Modelling of Dynamic Systems." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-171305.
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As tools for dynamic system modelling both conventional methods such as transfer function or state space representation and modern power flow based methods are available. The latter methods do not depend on energy domain, are able to preserve physical system structures, visualize power conversion or coupling or split, identify power losses or storage, run on conventional software and emphasize the relevance of energy as basic principle of known physical domains. Nevertheless common control structures as well as analysis and design tools may still be applied. Furthermore the generalization of power flow methods as pseudo-power flow provides with a universal tool for any dynamic modelling. The phenomenon of power flow constitutes an up to date education methodology. Thus the paper summarizes fundamentals of selected power flow oriented modelling methods, presents a Bond Graph block library for teaching power oriented modelling as compact menu-driven freeware, introduces selected examples and discusses special features.
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McCoy, Timothy J. (Timothy John). "Dynamic simulation of shipboard electric power systems." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12495.
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Roa-Sepulveda, C. A. "Dynamic simulation of voltage instability phenomena in power systems." Thesis, Imperial College London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390456.
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Yang, Dan. "Power system dynamic security analysis via decoupled time domain simulation and trajectory optimization." [Ames, Iowa : Iowa State University], 2006.
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7
Abed, Nagy Youssef. "Physical dynamic simulation of shipboard power system components in a distributed computational environment." FIU Digital Commons, 2007. http://digitalcommons.fiu.edu/etd/1100.
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Shipboard power systems have different characteristics than the utility power systems. In the Shipboard power system it is crucial that the systems and equipment work at their peak performance levels.
One of the most demanding aspects for simulations of the Shipboard Power Systems is to connect the device under test to a real-time simulated dynamic equivalent and in an environment with actual hardware in the Loop (HIL). The real time simulations can be achieved by using multi-distributed modeling concept, in which the global system model is distributed over several processors through a communication link. The advantage of this approach is that it permits the gradual change from pure simulation to actual application.
In order to perform system studies in such an environment physical phase variable models of different components of the shipboard power system were developed using operational parameters obtained from finite element (FE) analysis.
These models were developed for two types of studies low and high frequency studies. Low frequency studies are used to examine the shipboard power systems behavior under load switching, and faults. High-frequency studies were used to predict abnormal conditions due to overvoltage, and components harmonic behavior. Different experiments were conducted to validate the developed models. The Simulation and experiment results show excellent agreement.
The shipboard power systems components behavior under internal faults was investigated using FE analysis. This developed technique is very curial in the Shipboard power systems faults detection due to the lack of comprehensive fault test databases.
A wavelet based methodology for feature extraction of the shipboard power systems current signals was developed for harmonic and fault diagnosis studies.
This modeling methodology can be utilized to evaluate and predicate the NPS components future behavior in the design stage which will reduce the development cycles, cut overall cost, prevent failures, and test each subsystem exhaustively before integrating it into the system.
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Zhang, Peng. "Shifted frequency analysis for EMTP simulation of power system dynamics." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/7727.
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Electromagnetic Transients Program (EMTP) simulators are being widely used in power
system dynamics studies. However, their capability in real time simulation of power systems is
compromised due to the small time step required resulting in slow simulation speeds.
This thesis proposes a Shifted Frequency Analysis (SFA) theory to accelerate EMTP
solutions for simulation of power system operational dynamics. A main advantage of the SFA is
that it allows the use of large time steps in the EMTP solution environment to accurately
simulate dynamic frequencies within a band centered around the fundamental frequency.
The thesis presents a new synchronous machine model based on the SFA theory, which
uses dynamic phasor variables rather than instantaneous time domain variables. Apart from using
complex numbers, discrete-time SFA synchronous machine models have the same form as the
standard EMTP models. Dynamic phasors provide envelopes of the time domain waveforms and
can be accurately transformed back to instantaneous time values. When the frequency spectra of
the signals are close to the fundamental power frequency, the SFA model allows the use of large
time steps without sacrificing accuracy. Speedups of more than fifty times over the traditional
EMTP synchronous machine model were obtained for a case of mechanical torque step changes.
This thesis also extends the SFA method to model induction machines in the EMTP. By
analyzing the relationship between rotor and stator physical variables, a phase-coordinate model
with lower number of equations is first derived. Based on this, a SFA model is proposed as a
general purpose model capable of simulating both fast transients and slow dynamics in induction
machines. Case study results show that the SFA model is in excess of seventy times faster than
the phase-coordinate EMTP model when simulating the slow dynamics.
In order to realize the advantage of SFA models in the context of the simulation of the
complete electrical network, a dynamic-phasor-based EMTP simulation tool has been developed.
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Kook, Kyung Soo Soo. "Dynamic Model Based Novel Findings in Power Systems Analysis and Frequency Measurement Verification." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/27761.
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This study selects several new advanced topics in power systems, and verifies their usefulness using the simulation. In the study on ratio of the equivalent reactance and resistance of the bulk power systems, the simulation results give us the more correct value of X/R of the bulk power system, which can explain why the active power compensation is also important in voltage flicker mitigation. In the application study of the Energy Storage System(ESS) to the wind power, the new model implementation of the ESS connected to the wind power is proposed, and the control effect of ESS to the intermittency of the wind power is verified. Also this study conducts the intensive simulations for clarifying the behavior of the wide-area power system frequency as well as the possibility of the on-line instability detection.
In our POWER IT Laboratory, since 2003, the U.S. national frequency monitoring network (FNET) has been being continuously operated to monitor the wide-area power system frequency in the U.S. Using the measured frequency data, the event of the power system is triggered, and its location and scale are estimated. This study also looks for the possibility of using the simulation technologies to contribute the applications of FNET, finds similarity of the event detection orders between the frequency measurements and the simulations in the U.S. Eastern power grid, and develops the new methodology for estimating the event location based on the simulated N-1 contingencies using the frequency measurement.
It has been pointed out that the simulation results can not represent the actual response of the power systems due to the inevitable limit of modeling power systems and different operating conditions of the systems at every second. However, in the circumstances that we need to test such an important infrastructure supplying the electric energy without taking any risk of it, the software based simulation will be the best solution to verify the new technologies in power system engineering and, for doing this, new models and better application of the simulation should be proposed.
Conducting extensive simulation studies, this dissertation verified that the actual X/R ratio of the bulk power systems is much lower than what has been known as its typical value, showed the effectiveness of the ESS control to mitigate the intermittence of the wind power from the perspective of the power grid using the newly proposed simulation model of ESS connected to the wind power, and found many characteristics of the wide-area frequency wave propagation. Also the possibility of using the simulated responses of the power system for replacing the measured data could be confirmed and this is very promising to the future application of the simulation to the on-line analysis of the power systems based on the FNET measurements.Ph. D.
10
Pearmine, Ross Stuart. "Review of primary frequency control requirements on the GB power system against a background of increasing renewable generation." Thesis, Brunel University, 2006. http://bura.brunel.ac.uk/handle/2438/724.
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The system frequency of a synchronous power system varies with the imbalance of energy supplied and the electrical energy consumed. When large generating blocks are lost, the system undergoes a frequency swing relative to the size of the loss. Limits imposed on the magnitude of frequency deviation† prevent system collapse. Operation of frequency responsive plant to control frequency, results in lower machine efficiencies. Changes to the generation mix on the British transmission system have occurred in the past ten years, when the response requirement was last reviewed. Future increased levels of wind turbines‡ will alter the operational characteristics of the system and warrant investigation. A process to optimise the response requirements while maintaining statutory limits on frequency deviation has been identified. The method requires suitable load and generator models to replicate transmission system performance. A value to substitute for current load sensitivity to frequency has been presented from empirical studies. Traditional coal fired generator models have been improved with additional functions to provide a comparable response with existing units. A novel combined cycle gas turbine model using fundamental equations and control blocks has also been developed. A doubly fed induction generator model, based on existing literature, has been introduced for representing wind turbine behaviour in system response studies. Validation of individual models and the complete system against historic loss events has established confidence in the method. A review of the current system with the dynamic model showed that current primary response requirements are inadequate. The secondary response requirements generally show a slight reduction in the holding levels. Simulations including extra wind generation have shown that there is potential to reduce the primary response requirement in the future. The secondary response requirements are maintained with added wind farms.
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Garcia-Valle, Rodrigo Joel. "Dynamic modelling and simulation of electric power systems using the Newton-Raphson method." Thesis, University of Glasgow, 2007. http://theses.gla.ac.uk/435/.
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The research work presented in this thesis is concerned with the development of a dynamic power flow computer algorithm using Newton's method. It addresses both the development of a positive sequence dynamic power flow algorithm for the dynamic study of balanced power systems and a fully-fledged three-phase dynamic power flow algorithm for the dynamic study of power systems exhibiting a significant degree of either structural or operational unbalance. As a prelude to the research work on dynamic power flows, a three-phase Newton-Raphson power flow algorithm in rectangular co-ordinates with conventional HVDC power plant modelling is presented in this thesis, emphasising the representation of converter control modes. The solution approach takes advantage of the strong numerical solutions for combined HVAC-HVDC systems, where power plant and operational imbalances are explicitly taken into account. The dynamic algorithm is particularly suited to carrying out long-term dynamic simulations and voltage stability assessments. Dynamic model representations of the power plants components and the load tap changing transformer are considered, and to widen the study range of dynamic voltage phenomena using this method, extensions have been made to include induction motor and polynomial load modelling features. Besides, reactive power compensators that base their modus operandi on the switching of power electronic valves, such as HVDC-VSC and the STATCOM are taken into account. The dynamic power flow algorithm has primarily been developed making use of the positive sequence and [dq] representations. Extensions are made to developing a three-phase power flows dynamic algorithm. Test cases for the various dynamic elements developed in this research are presented to show the versatility of the models and simulation tool, including a trip cascading event leading up to a wide-area voltage collaps. Comparisons with the output of a conventional transient stability program carried out where appropriate.
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Jain, Himanshu. "Dynamic Simulation of Power Systems using Three Phase Integrated Transmission and Distribution System Models: Case Study Comparisons with Traditional Analysis Methods." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/74234.
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Solar PV-based distributed generation has increased significantly over the last few years, and the rapid growth is expected to continue in the foreseeable future. As the penetration levels of distributed generation increase, power systems will become increasingly decentralized with bi-directional flow of electricity between the transmission and distribution networks. To manage such decentralized power systems, planners and operators need models that accurately reflect the structure of, and interactions between the transmission and distribution networks. Moreover, algorithms that can simulate the steady state and dynamics of power systems using these models are also needed. In this context, integrated transmission and distribution system modeling and simulation has become an important research area in recent years, and the primary focus so far has been on studying the steady state response of power systems using integrated transmission and distribution system models.
The primary objective of this dissertation is to develop an analysis approach and a program that can simulate the dynamics of three phase, integrated transmission and distribution system models, and use the program to demonstrate the advantages of evaluating the impact of solar PV-based distributed generation on power systems dynamics using such models. To realize this objective, a new dynamic simulation analysis approach is presented, the implementation of the approach in a program is discussed, and verification studies are presented to demonstrate the accuracy of the program. A new dynamic model for small solar PV-based distributed generation is also investigated. This model can interface with unbalanced networks and change its real power output according to the incident solar irradiation. Finally, application of the dynamic simulation program for evaluating the impact of solar PV units using an integrated transmission and distribution system model is discussed.
The dissertation presents a new approach for studying the impact of solar PV-based distributed generation on power systems dynamics, and demonstrates that the solar PV impact studies performed using the program and integrated transmission and distribution system models provide insights about the dynamic response of power systems that cannot be obtained using traditional dynamic simulation approaches that rely on transmission only models.Ph. D.
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Hrag, Margossian. "VALIDATION OF THE PSS/E MODEL FOR THE GOTLAND NETWORKR." Thesis, KTH, Elektriska energisystem, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-119577.
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The aim of the project is to revise the load flow and dynamic PSS/E models of the Gotland network and validate them against a set of measurements collected during a major disturbance, a three phase short circuit in the 70 kV system. The main task in revising the model is to convert the induction machine models of the wind turbines into user and manufacturer wind turbine models. The validation of the model is divided into two phases. The first is to use the measurements as well as some assumptions on the wind power generation and load distribution from the time of the fault to validate the dynamic behaviour of the system. The second is to use new measurements during a normal operation day. The latter would not be very helpful to illustrate the dynamic behaviour of the system, because of the lack of a major fault that would drastically affect the system, but it would nevertheless be useful to validate the load flow with greater accuracy.
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Arsoy, Aysen. "Electromagnetic Transient and Dynamic Modeling and Simulation of a StatCom-SMES Compensator in Power Systems." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/27225.
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Electromagnetic transient and dynamic modeling and simulation studies are presented for a StatCom-SMES compensator in power systems. The transient study aims to better understand the transient process and interaction between a high power/high voltage SMES coil and its power electronics interface, dc-dc chopper. The chopper is used to attach the SMES coil to a StatCom. Following the transient study, the integration of a StatCom with SMES was explored to demonstrate the effectiveness of the combined compensator in damping power oscillations. The transient simulation package PSCAD/EMTDC has been used to perform the integrated modeling and simulation studies.
A state of the art review of SMES technology was conducted. Its applications in power systems were discussed chronologically. The cost effective and feasible applications of this technology were identified. Incorporation of a SMES coil into an existing StatCom controller is one of the feasible applications, which can provide improved StatCom operation, and therefore much more flexible and controllable power system operation.
The SMES coil with the following unique design characteristics of 50MW (96 MW peak), 100 MJ, 24 kV interface has been used in this study. As a consequence of the high power/ high voltage interface, special care needs to be taken with overvoltages that can stress the insulation of the coil. This requires an investigation of transient overvoltages through a detailed modeling of SMES and its power electronics interface. The electrical model for the SMES coil was developed based on geometrical dimensions of the coil. The interaction between the SMES coil and its power electronics interface (dc-dc chopper for the integration to StatCom) was modeled and simulated to identify transient overvoltages. Transient suppression schemes were developed to reduce these overvoltages. Among these are MOV implementation, surge capacitors, different configurations of the dc-dc chopper.
The integration of the SMES coil to a StatCom controller was developed, and its dynamic behavior in damping oscillations following a three-phase fault was investigated through a number of simulation case studies. The results showed that the addition of energy storage to a StatCom controller can improve the StatCom-alone operation and can possibly reduce the MVA rating requirement for the StatCom operating alone. The effective location selection of a StatCom-SMES controller in a generic power system is also discussed.Ph. D.
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Whitlock, Rogers Jr. "Identification of Power System Stability Using Relevant Modes." ScholarWorks@UNO, 2011. http://scholarworks.uno.edu/td/1384.
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The purpose of this investigation is to identify appropriate location of capacitor banks and sources of reactive power by studying power system stability in the vicinity of system equilibrium states. The locations for reactive power sources are determined by identifying those modes of the system that participate most in the system behavior in general and in dictating the final state of the system after experiencing faults or disturbances. To identify the relevant modes of the system that participate most in the system dynamic, we shall make use of modal and participation analysis for different system conditions. We also apply modal and participation analysis to a system in order to identify the components of greatest impact that result in the most efficient system control. The ideas developed in this study are used to analyze and identify weak boundaries of the IEEE 39- Bus system that contribute to the system’s instability.
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Qiu, Qun. "Risk Assessment of Power System Catastrophic Failures and Hidden Failure Monitoring & Control System." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/11075.
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One of the objectives of this study is to develop a methodology, together with a set of software programs that evaluate, in a power system, the risks of catastrophic failures caused by hidden failures in the hardware or software components of the protection system.
The disturbance propagation mechanism is revealed by the analysis of the 1977 New York Blackout. The step-by-step process of estimating the relay hidden failure probability is presented. A Dynamic Event Tree for the risk-based analysis of system catastrophic failures is proposed. A reduced 179-bus WSCC sample system is studied and the simulation results obtained from California sub-system are analyzed. System weak links are identified in the case study. The issues relating to the load and generation uncertainties for the risk assessment of system vulnerabilities are addressed.
A prototype system - the Hidden Failure Monitoring and Control System (HFMCS) - is proposed to mitigate the risk of power system catastrophic failures. Three main functional modules - Hidden Failure Monitoring, Hidden Failure Control and Misoperation Tracking Database - and their designs are presented. Hidden Failure Monitoring provides the basis that allows further control actions to be initiated. Hidden Failure Control is realized by using Adaptive Dependability/Security Protection, which can effectively stop possible relay involvement from triggering or propagating disturbance under stressed system conditions.
As an integrated part of the HFMCS, a Misoperation Tracking Database is proposed to track the performance of automatic station equipment, hence providing automatic management of misoperation records for hidden failure analysis.Ph. D.
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Amaya, Gonzalez Hernan Andres. "Power Consumption Analysis of Rotorcraft Environmental Control Systems." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/9231.
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Helicopters have now become an essential part for civil and military activities, for the next few years a significant increase in the use of this mean of transportation is expected. Unlike many fixed-wing aircraft, helicopters have no need to be pressurized due to their operating at low altitudes. The Environmental Control Systems (ECS) commonly used in fixed-wing aircraft are air cycle systems, which use the engine compressor’s bleed flow to function. These systems are integrated in the aircraft from inception. The ECS in helicopters is commonly added subsequently to an already designed airframe and power plant or as an additional development for modern aircraft. Helicopter engines are not designed to bleed air while producing their rated power, due to this a high penalty in fuel consumption is paid by such refitted systems. A detailed study of the different configurations of ECS for rotorcraft could reduce this penalty by determining the required power resulting from each of the system configurations, and therefore recommend the most appropriate one to be implemented for a particular flight path and aircraft.
This study presents the conducted analysis and subsequent simulation of the environmental control system in a selected representative rotorcraft: the Bell206L-4. This investigation seeks to optimize the rotorcraft’s power consumption and energy waste; by taking into consideration the cabin heat load. It consequently aims to minimize these penalties, achieving passenger comfort, an optimally moist air for equipment and a reduction in the environmental impact.
For the purpose of this analysis a civil aircraft was chosen for a rotary-wing type. This helicopter was analysed with different air-conditioning packs complying with the current airworthiness requirements. These systems were optimized with the inclusion of different environmental control models, and the cabin heat load model, which provided the best air-conditioning for many conditions and mission scopes, thus reducing the high fuel consumption in engines and hence the emission of gases into the environment. Each of the models was computed in the Matlab-simulink® software.
Different case studies were carried out by changing aircraft, the system’s configurations and flight parameters. Comparisons between the different systems and sub-systems were performed. The results of these simulations permitted the ECS configuration selection for optimal fuel consumption. Once validated the results obtained through this model were included in Rotorcraft Mission Energy Management Model (RMEM), a tool designed to predict the power requirements of helicopter systems.
The computed ECS model shows that favourable reductions in fuel burn may be achievable if an appropriated configuration of ECS is chosen for a light rotorcraft. The results show that the VCM mixed with engine bleed air is the best configuration for the chosen missions. However, this configuration can vary according to the mission and environment.
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Josefsson, Andreas. "Identification and Simulation Methods for Nonlinear Mechanical Systems Subjected to Stochastic Excitation." Doctoral thesis, Karlskrona : Blekinge Institute of Technology, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-00507.
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With an ongoing desire to improve product performance, in combination with the continuously growing complexity of engineering structures, there is a need for well-tested and reliable engineering tools that can aid the decision making and facilitate an efficient and effective product development. The technical assessment of the dynamic characteristics of mechanical systems often relies on linear analysis techniques which are well developed and generally accepted. However, sometimes the errors due to linearization are too large to be acceptable, making it necessary to take nonlinear effects into account. Many existing analysis techniques for nonlinear mechanical systems build on the assumption that the input excitation of the system is periodic and deterministic. This often results in highly inefficient analysis procedures when nonlinear mechanical systems are studied in a non-deterministic environment where the excitation of the system is stochastic. The aim of this thesis is to develop and validate new efficient analysis methods for the theoretical and experimental study of nonlinear mechanical systems under stochastic excitation, with emphasis on two specific problem areas; forced response simulation and system identification from measurement data. A fundamental concept in the presented methodology is to model the nonlinearities as external forces acting on an underlying linear system, and thereby making it possible to use much of the linear theories for simulation and identification. The developed simulation methods utilize a digital filter to achieve a stable and condensed representation of the linear subparts of the system which is then solved recursively at each time step together with the counteracting nonlinear forces. The result is computationally efficient simulation routines, which are particularly suitable for performance predictions when the input excitation consist of long segments of discrete data representing a realization of the stochastic excitation of the system. Similarly, the presented identification methods take advantage of linear Multiple-Input-Multiple-Output theories for random data by using the measured responses to create artificial inputs which can separate the linear system from the nonlinear parameters. The developed methods have been tested with extensive numerical simulations and with experimental test rigs with promising results. Furthermore, an industrial case study of a wave energy converter, with nonlinear characteristics, has been carried out and an analysis procedure capable of evaluating the performance of the system in non-deterministic ocean waves is presented.
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Daepp, Hannes Gorkin. "Development of a multi-platform simulation for a pneumatically-actuated quadruped robot." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/45927.
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Successful development of mechatronic systems requires a combination of targeted hardware and software design. The compact rescue robot (CRR), a quadruped pneumatically-actuated walking robot that seeks to use the benefits garnered from pneumatic power, is a prime example of such a system. This thesis discusses the development and testing of a simulation that will aid in further design and development of the CRR by enabling users to examine the impacts of pneumatic actuation on a walking robot. However, development of an entirely new dynamic simulation specific to the system is not practical. Instead, the simulation combines a MATLAB/Simulink actuator simulation with a readily available C++ dynamics library. This multi-platform approach results in additional incurred challenges due to the transfer of data between the platforms. As a result, the system developed here is designed in the fashion that provides the best balance of realistic behavior, model integrity, and practicality. An analytically derived actuator model is developed using classical fluid circuit modeling together with nonlinear area and pressure curves to model the valve and a Stribeck-Tanh model to characterize the effects of friction on the cylinder. The valve model is designed in Simulink and validated on a single degree-of-freedom test rig. This actuator model is then interfaced with SrLib, a dynamics library that computes dynamics of the robot and interactions with the environment, and validated through comparisons with a CRR prototype. Conclusions are focused on the final composition of the simulation, its performance and limitations, and the benefits it offers to the system as a whole.
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Venturi, Elisa. "Dynamic simulation and analysis of a Passive House case study with direct PV system for heating and domestic hot water production." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16590/.
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Different heating systems for space heating and domestic hot water (DHW) preparation are investigated with respect to their energy efficiency. In particular, a case study of a multi-storey Passive House (called An-der-Lan) is analysed by means of dynamic simulations.
The first part of dynamic simulations focuses on the comparison of the UA and RC models for a simple office located in Rome. This is a case study from the project IEA SHC T56 – System Simulation Models. In particular, attention is put on the influence of the thermal capacity. Assuming the RC model as the reference case, variants of the UA model with different percentages of the thermal capacity are simulated, in order to find out the most similar to the RC model. The same investigation is carried out for the An-der-Lan building. In general, it is not possible to identify the best UA model, because for every considered quantity, the minimum difference between the UA and RC model is got for a different percentage of the thermal mass.
The second part of dynamic simulation focuses on the comparison among different systems for heating and DHW preparation. The realized system is direct electric heating for both space heating and DHW preparation. It is denoted as the reference Case1 and it is compared against alternative solutions. Case2 is based on a central air/water heat pump system for both heating and DHW production. A sensitivity analysis study is conducted. Finally, Case3 and Case4 are a mix of the previous two cases.
Results show that Case2 is the best in terms of electric energy required from the grid, although it is the system with the highest thermal losses. Furthermore, the PV system only in the south façade is not sufficient to cover the energy required in neither of the cases.
Finally, annual, monthly, daily, hourly and 10 minutes balances are compared. Results show the importance of smaller time step in balances between required and produced energy, in order to have more precise results.
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Munukuntla, Sowmya. "Sensitivity Analysis of Synchronous Generators for Real-Time Simulation." ScholarWorks@UNO, 2016. http://scholarworks.uno.edu/td/2172.
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The purpose of this thesis is to validate generator models for dynamic studies of power systems using PSS/E (Power System Simulator for Engineering), EMTP (ElectroMagnetic Transient Program), and Hypersim. To thoroughly evaluate the behavior of a power system in the three specified software packages, it is necessary to have an accurate model for the power system, especially the generator which is of interest. The effect of generator modeling on system response under normal conditions and under faulted conditions is investigated in this work. A methodology based on sensitivity analysis of generator model parameters is proposed aiming to homogenize the behavior of the same power system that is modeled in three software packages. Standard IEEE 14-Bus system is used as a test case for this investigation. Necessary changes in the exciter parameters are made using the proposed methodology so that the system behaves identical across all three software platforms.
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Soltani, Amirmasoud. "Low cost integration of Electric Power-Assisted Steering (EPAS) with Enhanced Stability Program (ESP)." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/8829.
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Vehicle Dynamics Control (VDC) systems (also known as Active Chassis systems) are mechatronic systems developed for improving vehicle comfort, handling and/or stability. Traditionally, most of these systems have been individually developed and manufactured by various suppliers and utilised by automotive manufacturers. These decentralised control systems usually improve one aspect of vehicle performance and in some cases even worsen some other features of the vehicle. Although the benefit of the stand-alone VDC systems has been proven, however, by increasing the number of the active systems in vehicles, the importance of controlling them in a coordinated and integrated manner to reduce the system complexity, eliminate the possible conflicts as well as expand the system operational envelope, has become predominant. The subject of Integrated Vehicle Dynamics Control (IVDC) for improving the overall vehicle performance in the existence of several VDC active systems has recently become the topic of many research and development activities in both academia and industries Several approaches have been proposed for integration of vehicle control systems, which range from the simple and obvious solution of networking the sensors, actuators and processors signals through different protocols like CAN or FlexRay, to some sort of complicated multi-layered, multi-variable control architectures. In fact, development of an integrated control system is a challenging multidisciplinary task and should be able to reduce the complexity, increase the flexibility and improve the overall performance of the vehicle. The aim of this thesis is to develop a low-cost control scheme for integration of Electric Power-Assisted Steering (EPAS) system with Enhanced Stability Program (ESP) system to improve driver comfort as well as vehicle safety. In this dissertation, a systematic approach toward a modular, flexible and reconfigurable control architecture for integrated vehicle dynamics control systems is proposed which can be implemented in real time environment with low computational cost. The proposed control architecture, so named “Integrated Vehicle Control System (IVCS)”, is customised for integration of EPAS and ESP control systems. IVCS architecture consists of three cascade control loops, including high-level vehicle control, low-level (steering torque and brake slip) control and smart actuator (EPAS and EHB) control systems. The controllers are designed based on Youla parameterisation (closed-loop shaping) method. A fast, adaptive and reconfigurable control allocation scheme is proposed to coordinate the control of EPAS and ESP systems. An integrated ESP & ESP HiL/RCP system including the real EPAS and Electro Hydraulic Brake (EHB) smart actuators integrated with a virtual vehicle model (using CarMaker/HiL®) with driver in the loop capability is designed and utilised as a rapid control development platform to verify and validate the developed control systems in real time environment. Integrated Vehicle Dynamic Control is one of the most promising and challenging research and development topics. A general architecture and control logic of the IVDC system based on a modular and reconfigurable control allocation scheme for redundant systems is presented in this research. The proposed fault tolerant configuration is applicable for not only integrated control of EPAS and ESP system but also for integration of other types of the vehicle active systems which could be the subject of future works.
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Andrade, José Geraldo Barreto Monteiro de. "Uma contribuição ao estudo da estabilidade de tensão em sistemas elétricos de potência: novos aspectos relacionados à representação da carga." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-08012008-120024/.
Full textAbstract:
Esse trabalho investiga o impacto do comportamento transitório e em regime permanente da carga sobre a estabilidade de tensão do sistema elétrico. Para isso, utiliza-se uma modelagem detalhada da rede elétrica, capaz de representar os principais eventos inerentes aos fenômenos de instabilidade e colapso de tensão. A simulação numérica do sistema algébrico-diferencial resultante é realizada utilizando-se o solver DASSLC. Ao final desse trabalho, faz-se uma análise da resposta dos diferentes modelos de carga sobre a estabilidade de tensão do sistema de 14 barras do IEEE.This work investigates the impact of transient and steady state load behavior on power systems voltage stability. In order to do this, a detailed electric power system model is used to reproduce the main aspects of voltage instability and collapse phenomena. The numerical solution of the resulting non-linear differential-algebraic equations is carried out by using the DASSLC solver. An analysis of different load models behaviour for some voltage instability situations is presented for IEEE 14 bus system.
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Blervaque, Hubert. "Règles de modélisation des systèmes énergétiques dans les bâtiments basse consommation." Thesis, Paris, ENMP, 2014. http://www.theses.fr/2014ENMP0032/document.
Full textAbstract:
La réduction des besoins dans les bâtiments à basse consommation d'énergie (BBC) nécessite un réexamen de l'approche de modélisation des systèmes énergétiques dans les outils de simulation. L'approche proposée repose sur une modélisation plus fine des phénomènes physiques incluant la régulation en boucle fermée du système énergétique couplé au bâtiment. A partir de l'identification des phénomènes propres au comportement énergétique des BBC, des recommandations, ou règles de modélisation, sont établies pour le développement des modèles de leurs systèmes énergétiques. Ces recommandations sont mises en application dans deux études. Tout d'abord, une simulation dynamique d'un bâtiment et de son système conduit à un dimensionnement plus adapté comparé aux méthodes classiques dans le cas de BBC avec des répercussions sur les appels de puissance et la consommation d'énergie. Ensuite, une analyse de sensibilité par la méthode de Morris sur une représentation générique du système énergétique a permis d'identifier les paramètres nécessitant d'être connus avec précision. La différence entre l'approche développée et la simulation horaire avec régulation idéale n'est que de quelques pourcents en besoins énergétiques pour un bâtiment existant mais elle passe à plus de 20% dans un bâtiment BBC. Un écart du même ordre de grandeur peut être identifié pour la détermination de la performance énergétique globale du système par une prise en compte plus détaillée des phénomènes de cyclage, de charge partielle ou de consommation des auxiliairesThe decrease of heat demands in low energy buildings requires to examine again modeling approaches in building energy simulation tools. The developed approach is based on a more accurate modeling of physical phenomena including the closed loop control between the HVAC system and the building. From the identification of the phenomena that specifically impact the energy behavior of the low energy buildings, some recommendation, or modeling rule, are established for the development of their HVAC systems. Those recommendations are applied in two case studies. Firstly, a dynamic simulation of a building and its system offers a better evaluation of the design power for a low energy building, affecting power demands and energy consumption. Then, a sensitivity analysis from Morris method on a generic representation of the HVAC system identifies the parameters to be accurately known. The difference between the developed approach and an hourly simulation with an ideal control is low for the evaluation of the heat load in an existing building but it is more than 20% in a low energy buildings. A difference of the same order of magnitude can be identified in the determination of the overall energy performance of the system by a more detailed consideration of the phenomena of cycling, the part load or the consumption of auxiliaries
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Thornström, Axel. "Strömbegränsare i synkrongeneratorer : En studie av strömbegränsarmodeller i PSS/E." Thesis, Uppsala universitet, Elektricitetslära, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-282507.
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It is well known that a crucial factor determining the transmission capacity with regards to the voltage stability limit of a stressed power system, is the limitation of field and stator current of overexcited generators. These limiters are commonly referred to as overexcitation limiters (OEL) and stator current limiters (SCL). This thesis investigates the representation of overexcitation limiters and stator current limiters in the Swedish power system and how they could be implemented in the power system simulator PSS/E. Dynamic simulations in PSS/E are performed to investigate and validate differences between model types and parameters. The thesis compares different types of limiters and presents a representative set of parameters based on the documentation and implements them into PSS/E. The result from the study is a recommendation to migrate to limiter model MAXEX2 for generators without stator current limiters. The MAXEX2 model uses an inverse time characteristic which is becoming more common in installed voltage regulators. This feature makes it possible for extended use of generators before limiter action is applied. The MAXEX2 model is also possible to tune into a fixed time delay to represent older types of limiters.
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Al-Ani, Jonathan. "Development of a Nordic BWR plant model in APROS and design of a power controller using the control rods." Thesis, KTH, Fysik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-289560.
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In this master thesis an input-model of a Nordic BWR power plant has been developed in APROS. The plant model contains key systems and major thermohydraulic components of the steam cycle, including I&C systems (i.e. power, pressure, level and flow controls). The plant model is primarily designed for balance of plant studies at discrete power levels. The input-model of the power plant focuses especially on the steam cycle which is crucial for analysing water and steam behaviour and its influence on the reactor power. At the current stage, the model primarily handles steady-state conditions of full-power operation, which has been the design point. It has also been shown that reduced-power operation can be simulated with a reasonable trendline of pressure and temperature progression over facility components.Inom ramen för examensarbete har en indatafil (modell) av en nordisk kokvattenreaktor, BWR, utvecklats i simuleringsverktyget APROS. Anläggningsmodellen är främst utformad för att simulera diskreta effektnivåer och innehåller viktiga system och termohydrauliska komponenter som ingår i ångcykeln, inklusive instrumenterings- och kontrollutrustning (dvs. effekt-, tryck-, nivå- och flödesreglering). Fokus har lagts särskilt på att få till en bra representation av ångcykeln, vilket är avgörande för analys av vatten- och ångbeteendet och dess påverkan på reaktoreffekten. Modellen kan främst användas för simulering av jämviktstillstånd vid full effektdrift och till en viss grad även reducerad effektdrift.
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Delille, Gauthier Marc Aimé. "Contribution du Stockage à la Gestion Avancée des Systèmes Électriques : approches Organisationnelles et Technico-économiques dans les Réseaux de Distribution." Phd thesis, Ecole Centrale de Lille, 2010. http://tel.archives-ouvertes.fr/tel-00586088.
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Des solutions innovantes doivent être développées pour envisager l'avenir des systèmes électriques face à un nombre grandissant de contraintes. En particulier, le stockage d'énergie est pressenti comme un soutien indispensable à l'essor massif dans les réseaux de distribution de sources de production exploitant les énergies renouvelables. Les présents travaux visent à apporter des éléments de réflexion sur cette option technique qui arrive à maturité et suscite l'intérêt. Dans un premier temps, des méthodes d'étude sont proposées pour cerner le potentiel et les opportunités du stockage distribué. Une grille de caractérisation des technologies est introduite et sa mise en œuvre souligne des performances intéressantes à des coûts qui, cependant, demeurent élevés. Pour rendre leur utilisation réaliste, la valeur de ces dispositifs pour les systèmes électriques est donc critique. Nous l'analysons en deux étapes : une classification de leurs services pour les différents acteurs en présence est définie avant d'aborder la mutualisation de fonctions, requise pour favoriser l'atteinte d'une rentabilité, via une approche originale. Cette démarche aboutit à l'identification de configurations porteuses qui méritent des études plus poussées. Pour ce faire, un modèle général de comportement des unités de stockage est développé dans un second temps. Interfacé à un logiciel de simulation dynamique des réseaux, il permet d'évaluer l'utilisation de telles installations pour diverses offres de services. Ces outils sont appliqués et validés expérimentalement sur la caractérisation d'une réserve impulsionnelle fournie par le stockage pour réduire les délestages dans les systèmes insulaires
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Zambelli, Monica de Souza. "Planejamento da operação energetica via curvas-guias de armazenamento." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259877.
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Orientadores: Secundino Soares Filho, Marcelo Agusto CicognaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: O setor elétrico brasileiro vem passando por sucessivas reformas na busca por um modelo institucional que permita a otimização do uso dos recursos energéticos, conciliada com o objetivo de se alcançar um desenvolvimento sustentável. O planejamento energético tem um papel fundamental neste contexto, de modo que estudos e pesquisas que forneçam suporte ao planejamento do setor energético e à elaboração de políticas energéticas de médio e longo prazo têm ganhado destaque entre as prioridades do setor elétrico brasileiro. A proposta deste trabalho é apresentar uma política operativa baseada no conceito de curvas-guias de armazenamento para o planejamento da operação energética de médio prazo. Essa política determina que, a cada estágio do período de planejamento, as decisões de vazão turbinada por cada usina hidrelétrica devem ser tais que mantenham seus reservatórios em níveis pré-estabelecidos por curvas-guias de armazenamento. A análise de desempenho dessa política operativa foi feita através de simulações da operação hidrotérmica, para sistemas de único reservatório e uma cascata do sistema elétrico brasileiro. Os resultados das simulações foram também comparados aos de políticas operativas mais robustas, incluindo o uso de programação dinâmica estocástica, técnica de solução já consolidada para o problema e utilizada atualmente no setor elétrico brasileiro. Os resultados demonstram que, apesar de simples e transparente, essa política operativa apresenta um desempenho competitivo para o planejamento da operação energética
Abstract: The Brazilian electric sector has been passing through successive reforms in the search for an institutional model that allows the optimization of the use of the energetic resources, concealed with the goal of achieving a sustaining development. The energetic planning plays a fundamental roll in this context, thus studies and researches designated to support planning in the energetic sector and elaboration of long term energetic policies have been gaining space among the Brazilian electric sector priorities. The proposal of this work is to present an operating policy based on the concept of storage guide-curves for the mid term hydrothermal scheduling. This policy determines that, at each stage of the planning period, the decisions of water discharged from each hydro plant must be such that keep their reservoirs at levels pre-determined by storage guide-curves. The performance analysis of this operating policy was done through operation simulation, considering different hydro plants of the Brazilian system. The simulation results were also compared to more robust operative policies, including the use of stochastic dynamic programming, a consolidated solution technique for the problem witch is actually in use by the Brazilian electric sector. The results demonstrate that, despite of simple and transparent, this operating policy presents a competitive performance for the hydrothermal scheduling
Mestrado
Energia Eletrica
Mestre em Engenharia Elétrica
29
Lee, Jae Ryong. "Analysis and simulation of dynamics of spacecraft power systems." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/53568.
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Comprehensive analyses, including dc, small-signal and large-signal analyses, of the dynamics of various spacecraft power systems are performed. Systems' dynamics are analyzed for various operating modes, such as the shunt, battery-charge and battery-discharge modes, as well as the transition mode. Computer models using the EASY5 program are developed for the Direct Energy Transfer (DET) system, solar array switching system and partial shunt system to facilitate design, analysis and performance verification.
Large-signal analyses are performed to identify stability conditions and to predict large-signal dynamic behavior for each mode of operation. The equivalent source and load characteristics of a solar array power system with a constant-power load, shunt regulator, battery charger and discharger, are identified to predict large-signal dynamic behavior. Employing the equivalent source and load, the state trajectories of shunt failure, battery discharger failure and solar array/battery lockup are predicted and verified through time-domain simulations.
Small-signal analyses of the DET system are performed for the three modes of operation. The system loop gain is defined. Design guidelines for the feedback control loop of the shunt regulator, battery charger and discharger are developed to shape the system loop gain for the optimum bus dynamic performance and stability of the system. Designed subsystems are simulated both in frequency-domain and time-domain to verify the design concept.
Various spacecraft power systems, such as solar array switching systems, a partial shunt system, a peak power tracking system and the COBE (Cosmic Background Explorer) power system are analyzed and simulated. Design guidelines of the power conditioning equipment for each system are provided.Ph. D.
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Geitner, Gert-Helge. "Modellbildung dynamischer Systeme mittels Leistungsfluß." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-97096.
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Im Beitrag wird zunächst die konventionelle auf Signalflüssen basierte Modellbildung mit modernen leistungsflussbasierten Methoden, die auf dem Prinzip von Aktion und Reaktion aufbauen, verglichen. BG (Bond Graph), POG (Power Oriented Graph) und EMR (Energetic Macroscopic representation) sind solche modernen Methoden die den Leistungsaustausch zwischen Teilsystemen als Grundlage für den Modellbildungsansatz nutzen. Diese Werkzeuge erhalten die physikalische Struktur, erlauben es in das dynamische System hineinzuschauen und unterstützen das Verständnis des Leistungsflusses. Unterschiede werden anhand verschiedener Eigenschaften in einer Tabelle angegeben. Nach Erläuterung der Grundlagen zu POG und BG erfolgt die Vorstellung einer Freeware Zusatzbibliothek zur Simulation von Bondgraphen. Spezielle Eigenschaften werden kurz umrissen. Diese Blockbibliothek läuft unter Simulink, besteht aus nur 9 mittels Menü konfigurierbaren Blöcken und realisiert bidirektionale Verbindungen. Die Beispiele Gleichstrommotor, Pulssteller und elastische Welle demonstrieren die Vorteile der leistungsflussorientierten Modellbildung. Zustandsregelung, Energieeffizienz und Simulink LTI Analysewerkzeuge führen in die Anwendung der vorgestellten Simulink Zusatzbibliothek für Bondgraphen einThe paper starts with a comparison of the conventional modelling method based on signal flow and modern power flow oriented modelling methods based on the principle of action and reaction. BG (Bond Graph), POG (Power Oriented Graph) and EMR (Energetic Macroscopic representation) are such modern methods based on the power exchange between partial systems as a key element for the basic modelling approach. These tools preserve the physical structure, enable a view inside dynamical systems and support understanding the power flow. Relationships between these graphical representations will be given. After the explanation of basics for POG and BG an overview and special features of a freeware add-on library for simulation of BGs will be outlined. The block library runs under Simulink, consists of nine menu-driven customised blocks only and realises bidirectional connections. Examples DC motor, chopper and elastic shaft demonstrate the advantages of power flow oriented modelling. State space control, energy efficiency and Simulink LTI analysis tools exemplify the application of the presented Simulink add-on BG library
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Silva, Thayze D'Martin Costa da 1988. "Princípio do equivalente certo no planejamento da operação de sistemas hidrotérmicos." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259879.
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Orientadores: Secundino Soares Filho, Mônica de Souza ZambelliDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
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Resumo: O Princípio do Equivalente Certo (PEC) garante que as abordagens determinística e estocástica são equivalentes na otimização de sistemas dinâmicos estocásticos quando satisfeitas certas condições. É possível que o problema de planejamento da operação energética (POE) se aproxime de satisfazer as condições do PEC, apesar de não atendê-las teoricamente. Assim, o objetivo desta dissertação é analisar a validade do PEC no âmbito da Programação Dinâmica aplicado ao POE de sistemas hidrotérmicos constituídos de um único reservatório e avaliar o impacto da violação de cada condição. As hipóteses do PEC foram analisadas progressivamente por meio da comparação dos resultados dos modelos considerados, desde o ideal que atende teoricamente às condições, até o mais próximo da realidade. Foram observadas diferenças pouco significativas entre as políticas de operação determinística e estocástica, indicando que o modelo de POE se aproxima de atender às condições do PEC. Uma consequência imediata deste estudo seria que a abordagem determinística do problema de POE para sistemas hidrotérmicos com um único reservatório pode ser tão eficaz quanto as abordagens estocásticas
Abstract: Certainty Equivalence Principle (CEP) ensures that deterministic and stochastic approaches are equivalent in stochastic dynamic systems optimization when some assumptions hold. It is possible that Long Term Hydrothermal Scheduling (LTHS) problem is close to attaining CEP¿s assumptions, although it does not attain them theoretically. Thus, the objective of this dissertation is to analyze the validity of CEP in Dynamic Programming framework applied to single reservoir LTHS problem and to evaluate the impacts of each CEP¿s condition violation. The CEP¿s conditions were progressive analyzed by comparison of the considered models results from an ideal case where theoretically assumptions hold until a case study closer to reality. Slight differences were observed between deterministic and stochastic operation policies, indicating that LTHS model is close to attain the CEP¿s conditions. An immediate consequence of this study would be that deterministic approach for the single reservoir LTHS problem can be as effective as stochastic ones
Mestrado
Energia Eletrica
Mestra em Engenharia Elétrica
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VISCONTI, IGOR FERREIRA. "MEASUREMENT-BASED LOAD MODELING FOR DYNAMIC SIMULATIONS ON ELECTRIC POWER SYSTEMS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2010. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=16417@1.
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CENTRO DE PESQUISA DE ENERGIA ELÉTRICAEste trabalho descreve uma metodologia para modelagem de cargas elétricas, utilizando dados de tensão e corrente registrados durante distúrbios no sistema de potência. Estes modelos são utilizados na representação de subsistemas da rede elétrica em simulações computacionais que preveem o comportamento dinâmico do sistema de potência após perturbações em suas condições normais de operação.São apresentados resultados práticos da metodologia proposta, onde a carga é definida como um sistema cuja saída é a variação da potência consumida e a entrada é a variação da tensão, ambas medidas em barramentos de 69 kV da Companhia Hidroelétrica do São Francisco (CHESF), ponto de entrega de energia para concessionárias distribuidoras de energia do nordeste brasileiro. Estas distribuidoras são modeladas como cargas, supridas pelo sistema de transmissão da CHESF e todos os elementos consumidores de energia são agregados nestes modelos equivalentes, parametrizados para simular o maior número de contingências típicas medidas em cada um destes barramentos de carga.A técnica de estimação de parâmetros dos modelos de cargas é o Algoritmo Genético (AG) cujos resultados apresentaram precisão para a simulação de contingências de características bem distintas, caracterizando a abrangência alcançada no processo de identificação de sistemas.Ao final do trabalho são apresentadas curvas de desvios de potência ativa e reativa causadas por afundamentos de tensão, ambos registrados nos barramentos das subestações da CHESF. Estas curvas foram utilizadas para estimar os parâmetros dos modelos, obtidos individualmente para cada uma das subestações estudadas.
This work describes a measurement-based load modeling methodology, using voltage and current data registered during power system disturbances. These load models are used on computational simulations for predicting power system stability after disturbances of system operational points. Practical results are presented of the proposed methodology, defining load as a system whose output is power deviation from its operational state and input is voltage sags, both measured at 69 kV bus bars of São Francisco Hydroelectric Company (CHESF), points of common coupling (PCC) between CHESF and local distribution utilities. Therefore, distribution utilities are seen as loads supplied by CHESF’s transmission system. All devices consuming power from the PCC are aggregated into an equivalent model, parameterized to simulate most typical contingencies measured by these 69kV load bars. Optimization technique used for load model parameter estimation is Genetic Algorithm (GA), showing his flexibility on implementation and good coverage and accuracy in the final results. At the end, it will be presented a set of active and reactive power curves during and after voltages sags, measured on CHESF’s substations. These curves were used as estimation data to parameterize load models for each substation chosen.
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Hockenberry, James Richard. "Power system dynamic load modeling." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42594.
Full text
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Flaxman, J. W. "Multi-microprocessor power system simulation." Thesis, Durham University, 1987. http://etheses.dur.ac.uk/6762/.
Full textAbstract:
This thesis presents the results of research performed into the simulation of electrical power systems using a set of microprocessors operating in parallel , The uses and methods of simulation on analog and single processor computers are discussed as well as on multiple processor machines . It then considers various methods already used in the field of simulation for both the dynamic and network sets of equations in detail and the problems of using them on parallel processors . Several possible methods of parallel simulation are proposed and the best of these developed into a detailed algorithm for simulating both the dynamic and network portions of the power system .The different types of multiprocessor system are looked at , both in terms of physical configuration and the type of hardware used to implement the different types of system .The problems inherent in parallel computing are discussed and a form of multiprocessor, suitable for the simulation algorithm, is then developed taking these problems Into account. The hardware is developed using widely available hardware and the algorithm Is then Implemented upon this hardware .The results obtained using the simulator show that the proposed system provides a more economical solution, both in terms of the time taken in producing results and in the cost of the system, when compared with a conventional single processor computing system such as a mini computer.
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Geitner, Gert-Helge. "Modellbildung dynamischer Systeme mittels Leistungsfluß." Technische Universität Dresden, 2009. https://tud.qucosa.de/id/qucosa%3A26149.
Full textAbstract:
Im Beitrag wird zunächst die konventionelle auf Signalflüssen basierte Modellbildung mit modernen leistungsflussbasierten Methoden, die auf dem Prinzip von Aktion und Reaktion aufbauen, verglichen. BG (Bond Graph), POG (Power Oriented Graph) und EMR (Energetic Macroscopic representation) sind solche modernen Methoden die den Leistungsaustausch zwischen Teilsystemen als Grundlage für den Modellbildungsansatz nutzen. Diese Werkzeuge erhalten die physikalische Struktur, erlauben es in das dynamische System hineinzuschauen und unterstützen das Verständnis des Leistungsflusses. Unterschiede werden anhand verschiedener Eigenschaften in einer Tabelle angegeben. Nach Erläuterung der Grundlagen zu POG und BG erfolgt die Vorstellung einer Freeware Zusatzbibliothek zur Simulation von Bondgraphen. Spezielle Eigenschaften werden kurz umrissen. Diese Blockbibliothek läuft unter Simulink, besteht aus nur 9 mittels Menü konfigurierbaren Blöcken und realisiert bidirektionale Verbindungen. Die Beispiele Gleichstrommotor, Pulssteller und elastische Welle demonstrieren die Vorteile der leistungsflussorientierten Modellbildung. Zustandsregelung, Energieeffizienz und Simulink LTI Analysewerkzeuge führen in die Anwendung der vorgestellten Simulink Zusatzbibliothek für Bondgraphen ein.:Modellbildung dynamischer Systeme mittels Leistungsfluß
1. Leistungsfluß versus Signalfluß
2. Konjugierte Leistungsvariablen und Kausalität
3. Grundlagen Leistungsfluß orientierter Modellierung
3.1 Definitionen zum POG (Power Oriented Graph)
3.2 Definitionen zu Grundelementen für Bondgraphen (BG)
4. Freeware Bibliothek zur Simulation von Bondgraphen
4.1 Übersicht und Nutzerfreundlichkeit
4.2 Besonderheiten
5. Beispiele
5.1 Gleichstrommotor mit starrer Welle
5.2 Elastische Welle
5.3 Eingangsfilter und Pulssteller
5.4 Vereinfachter Antriebsstrang
6. Anwendung der Simulink Bondgraph Blockbibliothek
6.1 Beispiel elastische Welle
6.2 Zustandsregelung
6.3 Energieeffizienz
6.4 Simulink Analysewerkzeuge
7. Vorteile im ÜberblickThe paper starts with a comparison of the conventional modelling method based on signal flow and modern power flow oriented modelling methods based on the principle of action and reaction. BG (Bond Graph), POG (Power Oriented Graph) and EMR (Energetic Macroscopic representation) are such modern methods based on the power exchange between partial systems as a key element for the basic modelling approach. These tools preserve the physical structure, enable a view inside dynamical systems and support understanding the power flow. Relationships between these graphical representations will be given. After the explanation of basics for POG and BG an overview and special features of a freeware add-on library for simulation of BGs will be outlined. The block library runs under Simulink, consists of nine menu-driven customised blocks only and realises bidirectional connections. Examples DC motor, chopper and elastic shaft demonstrate the advantages of power flow oriented modelling. State space control, energy efficiency and Simulink LTI analysis tools exemplify the application of the presented Simulink add-on BG library.:Modellbildung dynamischer Systeme mittels Leistungsfluß 1. Leistungsfluß versus Signalfluß 2. Konjugierte Leistungsvariablen und Kausalität 3. Grundlagen Leistungsfluß orientierter Modellierung 3.1 Definitionen zum POG (Power Oriented Graph) 3.2 Definitionen zu Grundelementen für Bondgraphen (BG) 4. Freeware Bibliothek zur Simulation von Bondgraphen 4.1 Übersicht und Nutzerfreundlichkeit 4.2 Besonderheiten 5. Beispiele 5.1 Gleichstrommotor mit starrer Welle 5.2 Elastische Welle 5.3 Eingangsfilter und Pulssteller 5.4 Vereinfachter Antriebsstrang 6. Anwendung der Simulink Bondgraph Blockbibliothek 6.1 Beispiel elastische Welle 6.2 Zustandsregelung 6.3 Energieeffizienz 6.4 Simulink Analysewerkzeuge 7. Vorteile im Überblick
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Svensson, Oskar. "Electrohydraulic Power Steering Simulation : Dynamic, thermal and hydraulic modelling." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-265674.
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There are several benets of electrohydraulic power steering systems, as compared to hydraulicpower steering systems where the pump is driven directly by the engine of the vehicle. Someof these benets are increased eciency and improved steering performance. The purpose ofthis project is to create a simulation model of the electrohydraulic power steering system inSimulink, excluding the hydraulic circuit. The model should thus consist of the electric motor,the drive electronics, the control system, the hydraulic pump as well as the communication andinterface to the master simulation system in which the model will be used.As a start a mathematical model of the motor is derived. Then the motor controller includingtwo current controllers and a speed controller is developed. The switching signals for the threephase bridge that drives the motor are calculated using space vector modulation. The motordrives a hydraulic pump, which is modeled using data sheet eciency curves. Finally a thermalmodel of the drive is developed. To fulll real time requirements, a lumped parameter approachis chosen. The nal model is exported as a Functional Mock-up Unit, which is a black-boxencapsulation of the complete simulation model.The simulation model is compared to measurement data to conrm its validity. Thesecomparisons shows that the dynamic response of the motor and its controller are close to themeasured values and that the thermal model adequately corresponds to the thermal tests. Thehydraulic pump model varied from measurements more than the other sub-modules. It was,however, seen as acceptable. Overall the system response was satisfactory, but naturally a lotof future improvements and new features could be made to improve the model.Det finns flera fördelar med elektrohydraulisk servostyrning, där hydraulpumpen drivs av en el-motor, jämfört med hydraulisk servostyrning, där pumpen drivs direkt av fordonets förbränningsmotor. Några av dessa fördelar är ökad effektivitet och förbättrad styrprestanda. Syftet med detta projekt är att skapa en Simulink-modell av ett elektrohydraulisk system för servostyrning, exklusive hydraulkretsen. Modellen ska alltså bestå av delmodeller för elmotorn, drivelektroniken, styrsystemet, hydraulpumpen samt kommunikation med den övergripande simuleringsplattformen.Inledningsvis beskrivs en matematisk modell av elmotorn och efter det utvecklas motorstyrningen, bestående av två strömregulatorer samt en hastighetsregulator. Spänningen från strömregulatorerna uppnås genom space vector-modulation, som beräknar de pulskvoter som krävs för att uppnå denna spänning. Elmotorn driver en pump. Denna pump modelleras med hjälp av data från pumpens datablad. Slutligen modelleras drivelektronikens termiska egenskaper med ett termiskt nätverk. Den slutliga modellen omsluts av en Functional Mock-up Unit somintegreras i den övergripande simuleringsplattformen.
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Song, Xuefeng. "Dynamic modeling issues for power system applications." Texas A&M University, 2003. http://hdl.handle.net/1969.1/1591.
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Power system dynamics are commonly modeled by parameter dependent nonlinear differential-algebraic equations (DAE) x p y x f ) and 0 = p y x g ) . Due to
(,, (,, the algebraic constraints, we cannot directly perform integration based on the DAE. Traditionally, we use implicit function theorem to solve for fast variables y to get a reduced model in terms of slow dynamics locally around x or we compute y numerically at each x . However, it is well known that solving nonlinear algebraic equations analytically is quite difficult and numerical solution methods also face many uncertainties since nonlinear algebraic equations may have many solutions, especially around bifurcation points. In this thesis, we apply the singular perturbation method to model power system dynamics in a singularly perturbed ODE (ordinary-differential equation) form, which makes it easier to observe time responses and trace bifurcations without reduction process. The requirements of introducing the fast dynamics are investigated and the complexities in the procedures are explored. Finally, we propose PTE (Perturb and Taylors expansion) technique to carry out our goal to convert a DAE to an explicit state space form of ODE. A simplified unreduced Jacobian matrix is also introduced. A dynamic voltage stability case shows that the proposed method works well without complicating the applications.
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Singhavilai, Thamvarit. "Identification of electric power system dynamic equivalent." Thesis, University of Strathclyde, 2011. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=15647.
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Tsai, Shu-Jen Steven. "Study of Global Power System Frequency Behavior Based on Simulations and FNET Measurements." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/28303.
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A global view of power system's frequency opens up a new window to the "world" of large system's dynamics. With the aid of global positioning system (GPS), measurements from different locations can be time-synchronized; therefore, a system-wide observation and analysis would be possible. As part of the U.S. nation-wide power frequency monitoring network project (FNET), the first part of the study focuses on utilizing system simulation as a tool to assess the frequency measurement accuracy needed to observe frequency oscillations from events such as remote generation drops in three U.S. power systems. Electromechanical wave propagation phenomena during system disturbances, such as generation trip, load rejection and line opening, have been observed and discussed. Further uniform system models are developed to investigate the detailed behaviors of wave propagation. Visualization tool is developed to help to view frequency behavior simulations. Frequency replay from simulation data provides some insights of how these frequency electromechanical waves propagate when major events occur. The speeds of electromechanical wave propagation in different areas of the U.S. systems, as well as the uniform models were estimated and their characteristics were discussed. Theoretical derivation between the generator's mechanical powers and bus frequencies is provided and the delayed frequency response is illustrated.
Field-measured frequency data from FNET are also examined. Outlier removal and wavelet-based denoising signal processing techniques are applied to filter out spikes and noises from measured frequency data. System's frequency statistics of three major U.S. power grids are investigated. Comparison between the data from phasor measurement unit (PMU) at a high voltage substation and from FNET taken from 110 V outlets at distribution level illustrates the close tracking between the two. Several generator trip events in the Eastern Interconnection System and the Western Electricity Coordinating Council system are recorded and the frequency patterns are analyzed. Our trigger program can detect noticeable frequency drop or rise and sample results are shown in a 13 month period. In addition to transient states' observation, the quasi-steady-state, such as oscillations, can also be observed by FNET. Several potential applications of FNET in the areas of monitoring & analysis, system control, model validation, and others are discussed. Some applications of FNET are still beyond our imagination.Ph. D.
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Huynh, Quoc T. "Dynamic system simulation using graphically defined models." Thesis, Swansea University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637363.
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This thesis describes an approach to the digital simulation of dynamic systems in which the behaviour occurs continuously in time. Dynamic systems are modelled and synthesised in graphical forms, such as block diagrams and signal flow graph. The emphasis in this thesis has been on the block diagram form. A block diagram representation of a system model is graphically defined in the Control Engineering workStation (CES). Blocks in the block diagram can have realistic graphical symbols and meanings. Block operations can be defined in mathematical form, parameter-based form or text-based form. The graphically defined model in the form of a block diagram can be simulated using existing commercial simulation packages. For this purpose interfaces have been developed to allow CES to be integrated with two commercial simulation packages, ACSL and SIMNON, and can be extended to other packages if required. The user interaction with a simulation package has been carried out by graphical means, with the generation of simulation codes and the driving of the package being done automatically. Simulation results can be inspected in the graphical environment of CES. To exploit the topological and dynamic structures of system models represented in the form of block diagrams, for the purpose of parallel simulation, a graphical approach has been developed. This approach allows a concurrent simulation model to be expressed in a relatively simple manner, similar to that used with analog computers. Blocks and connections in the block diagram are considered to be separate communicating processes and communicative channels. Furthermore, these processes are considered as basic units to be allocated to processors. Based on this approach, a parallel transputer-based simulator has been developed. The transputer-based simulator has been linked to CES, using a mechanism similar to that used for linkage to commercial simulation packages.
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Donolo, Marcos A. "A continuum Approach to Power system simulation." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/29002.
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The behavior of large and tightly interconnected power systems resembles, in certain circumstances, the behavior of a continuously distributed system. This resemblance motivated the derivation of continuum models, which were used to explain and predict disturbance propagation, un-damped power oscillations, and the stability of power systems. In this dissertation, we propose a one-dimensional continuum representation suitable for meshed power systems. Previous continuous representations of meshed power systems used two-dimensional spatial domains. Thus our approach has the potential to provide better resolution for comparable computational burden. It is important to note that, the computational burden required to obtain solutions for PDEs involved in the continuum representation varies notably with the solver implementation.
The contributions of this dissertation are: a) Reviewing a previous continuum model and providing a detailed derivation for the one-dimensional version of it. b) Providing and describing in detail a parameter distribution technique adequate for the continuum approach. c) Identifying and documenting limitations on the continuum model voltage calculation. e) Providing a procedure to simulate the behavior of meshed power systems using the one dimensional continuum model. And f) Identifying and applying a numerical PDE solver for the continuum approach.Ph. D.
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Deoss, Dister Leroy. "A simulation model for dynamic system availability analysis." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/26241.
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Grygier, Paul Arthur. "Distributed Dynamic System Simulation Using a Computer Network." The Ohio State University, 1988. http://rave.ohiolink.edu/etdc/view?acc_num=osu1391676035.
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Thoret-Bauchet, Quentin. "Simulations du comportement vibratoire de réducteurs d'entrainement pour machine-outil : Applications à la détection et à l'identification de défauts." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI099.
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Ces travaux de thèse sont le résultat de la collaboration entre la société REDEX et le Laboratoire de Mécanique des Contacts et des Structures de l’INSA de Lyon. Ces travaux s’intéressent aux éléments de transmission de puissance du système de guidage d’une machine-outil, dont la conception va naturellement chercher à minimiser les erreurs de fabrication que la machine-outil pourrait générer. Dans le cadre de cette étude, un modèle dynamique de transmission pour machine-outil a été développé, comprenant un couple d’engrenages spiroconiques et un train épicycloïdal, incorporant de nombreuses erreurs d’assemblages et de forme des différents engrenages du système. Ce modèle mathématique à paramètres concentrés exploite des éléments d’engrenages cylindriques, d’engrenages coniques, d’arbres et de paliers. Les arbres sont modélisés par des poutres de Timoshenko, et les éléments de paliers se basent sur une linéarisation des relations effort-déplacement de Palmgren. Les surfaces de contact entre engrenages sont discrétisées en cellules élémentaires, auxquelles sont attribués une raideur élémentaire et un écart normal initial. Les écarts normaux initiaux des éléments d’engrenages sont mis à jour à chaque pas de temps pour prendre en compte les nouvelles positions angulaires relatives des composants et les potentielles erreurs de forme et d’assemblage. Les équations du mouvement sont résolues pas à pas dans le temps à l’aide d’un schéma de Newmark, couplé à un algorithme de gestion des contacts venant s’assurer de la bonne détermination des efforts de contact et des raideurs élémentaires des éléments d’engrenages. Les raideurs élémentaires des engrenages cylindriques sont déterminées suivant la méthode de Weber et Banaschek afin de prendre en compte la contribution des déformations de contact, de la flexion des dentures et de la fondation. Les raideurs élémentaires des engrenages spiroconiques sont déterminées à l’aide d’un élément de coque afin de rendre compte de la flexion de la dent, ainsi qu’à l’aide des théories de Boussinesq pour obtenir la contribution des déformations de contact. Un algorithme de calcul de distance de séparation tridimensionnel de type point sur plan est implémenté afin d’obtenir les écarts normaux initiaux des engrenages spiroconiques. Différents éléments de validation du modèle sont ensuite présentés afin de juger de l’exactitude du modèle et de ses limitations sur certains aspects de modélisation. Enfin, une étude du comportement dynamique du train épicycloïdal seul, du couple d’engrenages spiroconiques et du système complet est proposée, s’intéressant aux couplages existants entre ces deux éléments de la transmission, ainsi qu’à l’impact de différentes erreurs d’assemblages individuelles sur les erreurs de transmission et le coefficient de surcharge dynamique. Pour une même amplitude d’erreur, différents niveaux de criticité sont ainsi mis en valeur selon la nature de l’erreur et le mobile impactéThis research work has been conducted at the Contact and Structural Mechanics Laboratory (LaMCoS) of LaMCoS - INSA Lyon, in collaboration with REDEX. The very nature of machine-tools is to answer a need for automation and reliability of the manufacturing process of mechanical parts. The design stage of a machine-tool will therefore seek to minimise the manufacturing errors that the machine-tool could generate, in particular through the power transmission elements of the system guiding the relative displacements of the tool and the machined part. This work focuses on such power transmission elements. The present work introduces a dynamic model for geared machine-tool transmissions, comprising a pair of spiral bevel gears and an epicyclic gear train, and incorporating numerous shape and assembly errors of the various gears and rotating bodies of the system. This mathematical model adopts a lumped parameters approach, and employs specific elements of cylindrical gears and bevel gears, as well as shafts and bearings elements. The shafts are modelled using Timoshenko beams, and the bearing elements are based on a linearization of Palmgren force-displacement relations. The contact areas between gears are discretised into elemental cells, which are all attributed a local time-varying mesh stiffness element and an initial equivalent normal separation accounting for tooth flank faults and modifications. The initial equivalent normal separations of the gear elements are updated at each time step to account for the new relative angular positions of the components. The equations of motion are solved step-by-step over time using a Newmark integration scheme coupled with a normal contact algorithm to ensure that the contact efforts and the elemental mesh stiffness functions of the various gear elements are consistent. The elemental mesh stiffness functions of cylindrical gears are determined using the Weber and Banaschek approach account for the contribution of contact deformation, tooth bending and foundation displacements. The elemental mesh stiffness function of spiral bevel gears is determined using a shell element to account for tooth bending, and Boussinesq contact theory to account for the contribution of contact deformation. Various experimental and theoretical results are then presented and confronted with the model results to assess the accuracy and limitations of certain aspects of the model. Finally, a study of the dynamic behaviour of the epicyclic gear train, of the spiral bevel gear pair and of the complete system is proposed, focusing on the couplings between these two elements of the transmission, as well as on the impact of different individual assembly errors on the transmission errors and the dynamic overload coefficients. Different levels of criticality are thus highlighted depending on the nature of the error and the rotating body carrying the error
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Khamis, Ibrahim Ahmad 1956. "DYNAMIC SIMULATION OF A PROCESS INHERENT ULTIMATE SAFETY POWER PLANT (PIUS)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/275565.
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Scruggs, James N. "Power system availability determination through Petri net simulation." Ohio : Ohio University, 1995. http://www.ohiolink.edu/etd/view.cgi?ohiou1178910568.
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Taylor, Alistair James Eden. "Techniques for power system simulation using multiple processors." Thesis, Durham University, 1990. http://etheses.dur.ac.uk/5963/.
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The thesis describes development work which was undertaken to improve the speed of a real-time power system simulator used for the development and testing of control schemes. The solution of large, highly sparse matrices was targeted because this is the most time-consuming part of the current simulator. Major improvements in the speed of the matrix ordering phase of the solution were achieved through the development of a new ordering strategy. This was thoroughly investigated, and is shown to provide important additional improvements compared to standard ordering methods, in reducing path length and minimising potential pipeline stalls. Alterations were made to the remainder of the solution process which provided more flexibility in scheduling calculations. This was used to dramatically ease the run-time generation of efficient code, dedicated to the solution of one matrix structure, and also to reduce memory requirements. A survey of the available microprocessors was performed, which concluded that a special-purpose design could best implement the code generated at run-time, and a design was produced using a microprogrammable floating-point processor, which matched the code produced by the earlier work. A method of splitting the matrix solution onto parallel processors was investigated, and two methods of producing network splits were developed and their results compared. The best results from each method were found to agree well, with a predicted three-fold speed-up for the matrix solution of the C.E.G.B. transmission system from the use of six processors. This gain will increase for the whole simulator. A parallel processing topology of the partitioned network and produce the necessary structures for the remainder of the solution process.
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Kulasza, Matthew. "Generalized dynamic phasor-based simulation for power systems." 2015. http://hdl.handle.net/1993/30217.
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This thesis presents a new general purpose power system simulation technique based on dynamic phasors and conventional power system simulation methods. The method developed in this work converts time-domain circuits to equivalent dynamic phasor representations. These dynamic phasor equivalents are then simulated using nodal analysis and numerical integrator substitution. Simple linear circuit models are presented first in order to demonstrate that the new method is capable of accurately simulating small systems. The method developed in this work is then expanded to include control systems, power electronic converters, and synchronous machines. Visual comparisons with simulation results obtained using time-domain electromagnetic transient simulators demonstrate that the new dynamic phasor-based technique is capable of accurately simulating power system components.
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Nguyen, Hoai-Nam, and Nguyen H. N. "Study of Dynamic Simulation of Hybrid Pneumatic Power System." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/69344h.
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碩士國立臺北科技大學
車輛工程系所
97
The automotive manufacturing industry has been under tremendous pressure to develop high-efficiency power-train systems because of the considerations of protection of the global environment from vehicle pollution, reduction in fuel consumption, and maintenance of a high level of performance by end-user vehicles. Besides the conventional hybrid electric vehicles, an innovative hybrid pneumatic power system (HPPS) is undergoing research and considered to be a promising technology; it replaces the battery’s electrochemical energy with a high-pressure air storage tank and enables the internal combustion engine (ICE) to function at its sweet spot. The HPPS, which effectively merges both the high-pressure air flow from the storage tank and the recycled exhaust flow from the ICE, thereby increases the thermal efficiency of the ICE and transforms the merged flow energy into mechanical energy using a high efficiency turbine. This research focuses on the major research process into HPPSs, including overall dynamic simulation and experimental validation. By using the latest simulation tool ITI-Sim, this research demonstrates an experiment which can be operated precisely according to the requirements of various driving conditions under which a car actually runs on the road in accordance with the regulated running vehicle test mode. HPPS is expected to increase the energy, and therefore the performance, of the entire system from originally 15% to approximately 39%, and is likely to replace the traditional system in the coming years.
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Konara, Mudiyanselage Harshani Koushalya Konara. "Interfacing dynamic phasor based system equivalents to an electromagnetic transient simulation." 2016. http://hdl.handle.net/1993/31030.
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This thesis presents a method to do transient simulation of a large power system using dynamic phasors and electromagnetic transient simulation. A novel hybrid simulation technique using dynamic phasor equivalent is presented to analyse a part of a large power system. Electromagnetic transient simulation is used to model the part of the network that needs detailed simulation. The synchronous reference frame phase locked loop is implemented as the interface between the electromagnetic transient model and the dynamic phasor model. Two types of positive sequence filters i) sinusoidal signal integrator phase locked loop ii) extended phase locked loop are presented to eliminate the voltage unbalance effect in a phase locked loop. A comparison of the performance of the two filters is presented. The validation of the proposed interface is done using EMT simulation on real time digital simulator. Finally the numerical problems involved in this hybrid method are discussed.February 2016