Статті в журналах: "SIZING OF SVC"

1

Mohd Ali, Nur Zahirah, Ismail Musirin, and Hasmaini Mohamad. "Effect of SVC installation on loss and voltage in power system congestion management." Indonesian Journal of Electrical Engineering and Computer Science 14, no. 1 (April 1, 2019): 428. http://dx.doi.org/10.11591/ijeecs.v14.i1.pp428-435.

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In this paper, a new hybrid optimization technique is proposed namely Adaptive Embedded Clonal Evolutionary Programming (AECEP). This idea comes from the combination part of the clone in an Artificial Immune System (AIS) and then combined with Evolutionary Programming (EP). This technique was implemented to determine the optimal sizing of Flexible AC Transmission Systems (FACTS) devices. This study focused on the ability of Static Var Compensator (SVC) is used for the optimal operation of the power system as well as in reducing congestion in power system. In order to determine the location of SVC, the previous study has been done using pre-developed voltage stability index, Fast Voltage Stability Index (FVSI). Congested lines or buses will be identified based on the highest FVSI value for the purpose of SVC placement. The optimizations were conducted for the SVC sizing under single contingency, where SVC was modeled in steady state analysis. The objective function of this study is to minimize the power loss and improve the voltage profile along with the reduction of congestion with the SVC installation in the system. Validation on the IEEE 30 Bus RTS and IEEE 118 Bus RTS revealed that the proposed technique managed to reduce congestion in power system.

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Abdullah, Ali Najim, Ahmed Majeed Ghadhban, Hayder Salim Hameed, and Husham Idan Hussein. "Enhancement the stability of power system using optimal location of FACTS devices." Indonesian Journal of Electrical Engineering and Computer Science 18, no. 2 (May 1, 2020): 648. http://dx.doi.org/10.11591/ijeecs.v18.i2.pp648-655.

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This paper proposes a steady-state of the Static Var Compensator (SVC) & Thyristor Controlled Series Capacitor (TCSC) set up for enhancing the damping overall performance and growing the integral clearing time (CCT) of a power network. The indispensable clearing time is carried out through increasing the time fault interval until the gadget loses stability. Increasing the CCT can be contribute to reliability of the safety gadget, decrease the protection machine ranking and cost. In order to attain most enhancement of machine stability via optimizing location, sizing and control modes of SVC and TCSC. Models and methodology for putting and designing shunt FACT’s units SVC (injected reactive strength Q) and series FACT’s devices TCSC (chose capacitive region) are examined in a 6-bus system. Performance factors are described to show validation of SVC and TCSC on extraordinary conditions. It is proven that the SVC is better than TCSC.

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Duraisamy, Prasanth, and Arul Ponnusamy. "Power System Performance Improvement by Optimal Placement and Sizing of SVC using Genetic Algorithm." International Journal of Applied Power Engineering (IJAPE) 6, no. 2 (August 1, 2017): 55. http://dx.doi.org/10.11591/ijape.v6.i2.pp55-62.

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The power system loss minimization becomes more important as the need of power generation is more recent days. The loss minimization improves the voltage profile which improves the loadability of the system. In many types of flexible AC transmission system (FACTS) devices static var compensators (SVC) are cost vise it is affordable and it improves the system performance with lesser size. Here SVC is optimally placed in a test system of 30 bus system. Genetic algorithm is used to find the optimal results.

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Duraisamy, Prasanth, and Arul Ponnusamy. "Power System Performance Improvement by Optimal Placement and Sizing of SVC using Genetic Algorithm." International Journal of Applied Power Engineering (IJAPE) 6, no. 2 (August 1, 2017): 56. http://dx.doi.org/10.11591/ijape.v6.i2.pp56-63.

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The power system loss minimization becomes more important as the need of power generation is more recent days. The loss minimization improves the voltage profile which improves the loadability of the system. In many types of Flexible AC Transmission System (FACTS) devices Static Var Compensators (SVC) are cost vise it is affordable and it improves the system performance with lesser size. Here SVC is optimally placed in a test system of 30 bus system. Genetic algorithm is used to find the optimal results.

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5

Suyono, Hadi, Rini Nur Hasanah, and Paramita Dwi Putri Pranyata. "Optimization of the Thyristor Controlled Phase Shifting Transformer using PSO Algorithm." International Journal of Electrical and Computer Engineering (IJECE) 8, no. 6 (December 1, 2018): 5472. http://dx.doi.org/10.11591/ijece.v8i6.pp5472-5483.

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The increase of power system demand leads to the change in voltage profile, reliability requirement and system robustness against disturbance. The voltage profile can be improved by providing a source of reactive power through the addition of new power plants, capacitor banks, or implementation of Flexible AC Transmission System (FACTS) devices such as Static VAR Compensator (SVC), Unified Power Flow Control (UPFC), Thyristor Controlled Series Capacitor (TCSC), Thyristor Controlled Phase Shifting Transformer (TCPST), and many others. Determination of optimal location and sizing of device injection is paramount to produce the best improvement of voltage profile and power losses reduction. In this paper, optimization of the combined advantages of TCPST and TCSC has been investigated using Particle Swarm Optimization (PSO) algorithm, being applied to the 30-bus system IEEE standard. The effectiveness of the placement and sizing of TCPST-TCSC combination has been compared to the implementation of capacitor banks. The result showed that the combination of TCPST-TCSC resulted in more effective improvement of system power losses condition than the implementation of capacitor banks. The power losses reduction of 46.47% and 42.03% have been obtained using of TCPST-TCSC combination and capacitor banks respectively. The TCPST-TCSC and Capacitor Bank implementations by using PSO algorithm have also been compared with the implementation of Static VAR Compensator (SVC) using Artificial Bee Colony (ABC) Algorithm. The implementation of the TCSC-TCPST compensation with PSO algorithm have gave a better result than using the capacitor bank with PSO algorithm and SVC with the ABC algorithm.

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6

Santamaria-Henao, Nicolas, Oscar Danilo Montoya, and César Leonardo Trujillo-Rodríguez. "Optimal Siting and Sizing of FACTS in Distribution Networks Using the Black Widow Algorithm." Algorithms 16, no. 5 (April 27, 2023): 225. http://dx.doi.org/10.3390/a16050225.

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The problem regarding the optimal placement and sizing of different FACTS (flexible alternating current transmission systems) in electrical distribution networks is addressed in this research by applying a master–slave optimization approach. The FACTS analyzed correspond to the unified power flow controller (UPFC), the thyristor-controlled shunt compensator (TCSC, also known as the thyristor switched capacitor, or TSC), and the static var compensator (SVC). The master stage is entrusted with defining the location and size of each FACTS device using hybrid discrete-continuous codification through the application of the black widow optimization (BWO) approach. The slave stage corresponds to the successive approximations power flow method based on the admittance grid formulation, which allows determining the expected costs of the energy losses for a one-year operation period. The numerical results in the IEEE 33-, 69-, and 85-bus grids demonstrate that the best FACTS device for locating in distribution networks is the SVC, given that, when compared to the UPFC and the TCSC, it allows for the best possible reduction in the equivalent annual investment and operating cost. A comparative analysis with the General Algebraic Modeling System software, with the aim to solve the exact mixed-integer nonlinear programming model, demonstrated the proposed BWO approach’s effectiveness in determining the best location and size for the FACTS in radial distribution networks. Reductions of about 12.63% and 13.97% concerning the benchmark cases confirmed that the SVC is the best option for reactive power compensation in distribution grids.

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7

Thasnas, Natakorn, and Apirat Siritaratiwat. "Static Voltage Stability Margin Enhancement Using Shunt Capacitor, SVC and STATCOM." Applied Mechanics and Materials 781 (August 2015): 288–91. http://dx.doi.org/10.4028/www.scientific.net/amm.781.288.

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This paper presents the study of static voltage stability margin enhancement using shunt capacitor, SVC and STATCOM. AC and DC representations of shunt compensation devices are used in the continuation power flow process in static voltage stability study. Various performance measures including PV curves, voltage profiles, and power losses are compared. Placement and sizing techniques of shunt compensation devices are proposed for loading margin enhancement. The study has been carried out on the IEEE 14 bus test system.

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Hasma Abdullah, Nor Rul, Mahaletchumi A. P Morgan, Mahfuzah Mustafa, Rosdiyana Samad, and Dwi Pebrianti. "Multi-Objective Evolutionary Programming for Static VAR Compensator (SVC) in Power System Considering Contingencies (N-m)." International Journal of Power Electronics and Drive Systems (IJPEDS) 9, no. 2 (June 1, 2018): 880. http://dx.doi.org/10.11591/ijpeds.v9.i2.pp880-888.

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Static VAR Compensators (SVCs) is a Flexible Alternating Current Transmission System (FACTS) device that can control the power flow in transmission lines by injecting capacitive or inductive current components at the midpoint of interconnection line or in load areas. This device is capable of minimizing the overall system losses and concurrently improves the voltage stability. A line index, namely SVSI becomes indicator for the placement of SVC and the parameters of SVCs are tuned by using the multi-objective evolutionary programming technique, effectively able to control the power. The algorithm was tested on IEEE-30 Bus Reliability Test System (RTS). Comparative studies were conducted based on the performance of SVC in terms of their location and sizing for installations in power system.

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9

Mohd Ali, N. Z., I. Musirin, and H. Mohamad. "Clonal evolutionary particle swarm optimization for congestion management and compensation scheme in power system." Indonesian Journal of Electrical Engineering and Computer Science 16, no. 2 (November 1, 2019): 591. http://dx.doi.org/10.11591/ijeecs.v16.i2.pp591-598.

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This paper presents computational intelligence-based technique for congestion management and compensation scheme in power systems. Firstly, a new model termed as Integrated Multilayer Artificial Neural Networks (IMLANNs) is developed to predict congested line and voltage stability index separately. Consequently, a new optimization technique termed as Clonal Evolutionary Particle Swarm Optimization (CEPSO) was developed. CEPSO is initially used to optimize the location and sizing of FACTS devices for compensation scheme. In this study, Static VAR Compensator (SVC) and Thyristor Control Static Compensator (TCSC) are the two chosen Flexible AC Transmission System (FACTS) devices used in this compensation scheme. Comparative studies have been conducted between the proposed CEPSO and traditional Particle Swarm Optimization (PSO). Results obtained by the developed IMLANNs demonstrated high accuracy with respect to the targeted output. Consequently, the proposed CEPSO implemented for single objective in single unit of SVC and TCSC has resulted superior results as compared to the traditional PSO in terms of achieving loss reduction and voltage profile improvement.

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10

Prasath, R. Arun, M. Vimalraj, M. Riyas Ahamed, and K. Srinivasa Rao. "Power System Loadability Maximization by Optimal Placement of Multiple-Type FACTS Devices Using PSO Based GUI." Advanced Materials Research 984-985 (July 2014): 1286–94. http://dx.doi.org/10.4028/www.scientific.net/amr.984-985.1286.

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This paper presents a graphical user interface (GUI) uses Particle Swarm Optimization (PSO), which is used to find the optimal locations and sizing parameters of multi type Flexible AC transmission systems (FACTS) devices in complex power systems. The GUI toolbox, offers user to choose a power system network, PSO settings and the type and number of FACTS devices for the selected network. In this paper, three different FACTS devices are implemented: SVC, TCSC and TCPST. FACTS devices are used to increase the system loadability, by reducing power flow on overloaded lines, transmission line losses, improving system stability and security. With this can make the transmission system more energy-efficient. PSO used here for optimally allocating and sizing the multiple type FACTS in a standardized power network (IEEE 30 bus system) in order to improve voltage profile, minimizing power system total losses and maximizing system loadability with respect to the size of FACTS.

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Pană, Adrian, Alexandru Băloi, and Florin Molnar-Matei. "Iterative Method for Determining the Values of the Susceptances of a Balancing Capacitive Compensator." Energies 11, no. 10 (October 12, 2018): 2742. http://dx.doi.org/10.3390/en11102742.

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To increase the electrical power quality, in the last decades, an intense development in the last decades of high-performance equipment built as advanced power electronics applications, such as the compensators from Switching Power Converter category, has taken place. For all that, Reactive Power Compensators (RPC) based on passive circuit elements, such as Static var Compensators (SVCs), still occupy a wide range of applications in customer and installations of the distribution system installations. The functions of power factor (PF) improvement and load balancing in a three-phase distribution network can be achieved with an unbalanced SVC, known as the Adaptive Balancing Reactive Compensator (ABRC). Presenting first the mathematical model of the initial sizing and the working mechanism of a Balancing Reactive Compensator (BRC) for a three-phase four-wire network, this article develops a compensator resizing algorithm through an iterative change of the initial sizing to transform the compensator into a Balancing Capacitive Compensator (BCC), which keeps the same functions. By using two computational and modeling software tools, a case study on the application of the method was carried out, demonstrating the availability of the sizing problem solution and validating the unbalanced capacitive compensation as an efficient way to PF improving and load balancing in a PCC (Point of Common Coupling).

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M. Kanaan, H., M. EL-Gazaar, and M. A. Mehanna. "OPTIMAL LOCATION AND SIZING OF SVC CONSIDERING SYSTEM LOSSES, VOLTAGE DIVISION AND SYSTEM OVERLOAD." Journal of Al-Azhar University Engineering Sector 15, no. 57 (October 1, 2020): 1040–51. http://dx.doi.org/10.21608/auej.2020.120371.

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A. HEMA, SEKHAR, and DEVI A. LAKSHMI. "Optimal Sizing and Placement of Advanced SVC in Transmission System by Using Evolutionary Algorithms." i-manager’s Journal on Electrical Engineering 10, no. 3 (2017): 30. http://dx.doi.org/10.26634/jee.10.3.13412.

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Jaramillo, Manuel Dario, Diego Francisco Carrión, and Jorge Paul Muñoz. "A Novel Methodology for Strengthening Stability in Electrical Power Systems by Considering Fast Voltage Stability Index under N − 1 Scenarios." Energies 16, no. 8 (April 12, 2023): 3396. http://dx.doi.org/10.3390/en16083396.

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An electrical power system (EPS) is subject to unexpected events that might cause the outage of elements such as transformers, generators, and transmission lines. For this reason, the EPS should be able to withstand the failure of one of these elements without changing its operational characteristics; this operativity functionality is called N−1 contingency. This paper proposes a methodology for the optimal location and sizing of a parallel static Var compensator (SVC) in an EPS to reestablish the stability conditions of the system before N−1 contingencies take place. The system’s stability is analyzed using the fast voltage stability index (FVSI) criterion, and the optimal SVC is determined by also considering the lowest possible cost. This research considers N−1 contingencies involving the disconnection of transmission lines. Then, the methodology analyzes every scenario in which a transmission line is disconnected. For every one of them, the algorithm finds the weakest transmission line by comparing FVSI values (the higher the FVSI, the closer the transmission line is to instability); afterward, when the weakest line is selected, by brute force, an SVC with values of 5 Mvar to 100 Mvars in steps of 5 Mvar is applied to the sending bus bar of this transmission line. Then, the SVC value capable of reestablishing each line’s FVSI to its pre-contingency value while also reestablishing each bus-bar’s voltage profile and having the lowest cost is selected as the optimal solution. The proposed methodology was tested on IEEE 14, 30, and 118 bus bars as case studies and was capable of reestablishing the FVSI in each contingency to its value prior to the outage, which indicates that the algorithm performs with 100% accuracy. Additionally, voltage profiles were also reestablished to their pre-contingency values, and in some cases, they were even higher than the original values. Finally, these results were achieved with a single solution for a unique SVC located in one bus bar that is capable of reestablishing operational conditions under all possible contingency scenarios.

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Buraimoh, Elutunji, Funso Kehinde Ariyo, Micheal Omoigui, and Innocent Ewaen Davidson. "Investigation of Combined SVC and TCSC versus IPFC in Enhancing Power System Static Security." International Journal of Engineering Research in Africa 40 (December 2018): 119–35. http://dx.doi.org/10.4028/www.scientific.net/jera.40.119.

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Electrical power systems are often required to operate at full loading capacity due to ever increasing demand and transmission line contingencies with limited grid expansion. This results in line overload and operating near system limit, thereby threatening system security. Utilization of existing system can be achieved using Flexible Alternating Current Transmission System (FACTS) devices without violating system limits. This research investigation involves static security assessment of a modelled IEEE 30-bus test system in MATLAB/SIMULINK/PSAT environment. The security status with the incorporation of combined Static Var Compensator (SVC), Thyristor Controlled Series Compensator (TCSC) and Interline Power Flow Controller (IPFC) were determined. Prior to this, Contingency Severity Index (CSI) based on Performance Index (PI) of Voltage and Active Power was employed to determine the optimal location of the FACTS devices. Sequential Quadratic Programming (SQP) was applied to determine the optimal sizing/percentage compensation of FACTS. Subsequently, power system with and without the incorporation of FACTS devices were modelled. The ability of the compensated system to withstand credible transmission line contingencies without violating the normal operating limits (bus voltage and line thermal) was examined and presented. The paper presents how combined SVC/TCSC and an IPFC aided the power system to boost its steady state security in the face of possible line contingencies.

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Wang, Lina, Kamel Kerrouche, Abdelkader Mezouar, Alex Van Den Bossche, Azzedine Draou, and Larbi Boumediene. "Feasibility Study of Wind Farm Grid-Connected Project in Algeria under Grid Fault Conditions Using D-Facts Devices." Applied Sciences 8, no. 11 (November 15, 2018): 2250. http://dx.doi.org/10.3390/app8112250.

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The use of renewable energy such as wind power is one of the most affordable solutions to meet the basic demand for electricity because it is the cleanest and most efficient resource. In Algeria, the highland region has considerable wind potential. However, the electrical power system located is this region is generally not powerful enough to solve the problems of voltage instability during grid fault conditions. These problems can make the connection with the eventual installation of a wind farm very difficult and inefficient. Therefore, a wind farm project in this region may require dynamic compensation devices, such as a distributed-flexible AC transmission system (D-FACTS) to improve its fault ride through (FRT) capability. This paper investigates the implementation of shunt D-FACTS, under grid fault conditions, considering the grid requirements over FRT performance and the voltage stability issue for a wind farm connected to the distribution network in the Algerian highland region. Two types of D-FACTSs considered in this paper are the distribution static VAr compensator (D-SVC) and the distribution static synchronous compensator (D-STATCOM). Some simulation results show a comparative study between the D-SVC and D-STATCOM devices connected at the point of common coupling (PCC) to support a wind farm based on a doubly fed induction generator (DFIG) under grid fault conditions. Finally, an appropriate solution to this problem is presented by sizing and giving the suitable choice of D-FACTS, while offering a feasibility study of this wind farm project by economic analysis.

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17

Nadeem, Muhammad, Kashif Imran, Abraiz Khattak, Abasin Ulasyar, Anamitra Pal, Muhammad Zulqarnain Zeb, Atif Naveed Khan, and Malhar Padhee. "Optimal Placement, Sizing and Coordination of FACTS Devices in Transmission Network Using Whale Optimization Algorithm." Energies 13, no. 3 (February 8, 2020): 753. http://dx.doi.org/10.3390/en13030753.

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Flexible AC Transmission Systems (FACTS) play an important role in minimizing power losses and voltage deviations while increasing the real power transfer capacity of transmission lines. The extent to which these devices can provide benefits to the transmission network depend on their optimal location and sizing. However, finding appropriate locations and sizes of these devices in an electrical network is difficult since it is a nonlinear problem. This paper proposes a technique for the optimal placement and sizing of FACTS, namely the Thyristor-Controlled Series Compensators (TCSCs), Shunt VARs Compensators (SVCs), and Unified Power Flows Controllers (UPFCs). To find the optimal locations of these devices in a network, weak buses and lines are determined by constructing PV curves of load buses, and through the line stability index. Then, the whale optimization algorithm (WOA) is employed not only to find an ideal ratings for these devices but also the optimal coordination of SVC, TCSC, and UPFC with the reactive power sources already present in the network (tap settings of transformers and reactive power from generators). The objective here is the minimization of the operating cost of the system that consists of active power losses and FACTS devices cost. The proposed method is applied to the IEEE 14 and 30 bus systems. The presented technique is also compared with Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). The findings showed that total system operating costs and transmission line losses were considerably reduced by WOA as compared to existing metaheuristic optimization techniques.

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Mangaiyarkarasi, S. P., and T. Sree Renga Raja. "PSO Based Optimal Location and Sizing of SVC for Novel Multiobjective Voltage Stability Analysis during N – 2 Line Contingency." Archives of Electrical Engineering 63, no. 4 (December 11, 2014): 535–50. http://dx.doi.org/10.2478/aee-2014-0037.

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Abstract In this paper voltage stability is analysed based not only on the voltage deviations from the nominal values but also on the number of limit violating buses and severity of voltage limit violations. The expression of the actual state of the system as a numerical index like severity, aids the system operator in taking better security related decisions at control centres both during a period of contingency and also at a highly stressed operating condition. In contrary to conventional N – 1 contingency analysis, Northern Electric Reliability Council (NERC) recommends N – 2 line contingency analysis. The decision of the system operator to overcome the present contingency state of the system must blend harmoniously with the stability of the system. Hence the work presents a novel N – 2 contingency analysis based on the continuous severity function of the system. The study is performed on 4005 possible combinations of N – 2 contingency states for the practical Indian Utility 62 bus system. Static VAr Compensator is used to improve voltage profile during line contingencies. A multi- objective optimization with the objective of minimizing the voltage deviation and also the number of limit violating bus with optimal location and optimal sizing of SVC is achieved by Particle Swarm Optimization algorithm.

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Mohamed, Amal Amin, Salah Kamel, Mohamed H. Hassan, Mohamed I. Mosaad, and Mansour Aljohani. "Optimal Power Flow Analysis Based on Hybrid Gradient-Based Optimizer with Moth–Flame Optimization Algorithm Considering Optimal Placement and Sizing of FACTS/Wind Power." Mathematics 10, no. 3 (January 25, 2022): 361. http://dx.doi.org/10.3390/math10030361.

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Optimal power flow (OPF) is one of the most significant electric power network control and management issues. Adding unreliable and intermittent renewable energy sources to the electrical grid increase and complicates the OPF issue, which calls for using modern optimization techniques to solve this issue. This work presents the optimal location and size of some FACTS devices in a hybrid power system containing stochastic wind and traditional thermal power plants considering OPF. The FACTS devices used are thyristor-controlled series compensator (TCSC), thyristor-controlled phase shifter (TCPS), and static var compensator (SVC). This optimal location and size of FACTS devices was determined by introducing a multi-objective function containing reserve costs for overestimation and penalty costs for underestimating intermittent renewable sources besides active power losses. The uncertainty in the wind power output is predicted using Weibull probability density functions. This multi-objective function is optimized using a hybrid technique, gradient-based optimizer (GBO), and moth–flame optimization algorithm (MFO).

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Merah, Hana, Abdelmalek Gacem, Djilani Ben Attous, Abderezak Lashab, Francisco Jurado, and Mariam A. Sameh. "Sizing and Sitting of Static VAR Compensator (SVC) Using Hybrid Optimization of Combined Cuckoo Search (CS) and Antlion Optimization (ALO) Algorithms." Energies 15, no. 13 (July 1, 2022): 4852. http://dx.doi.org/10.3390/en15134852.

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Анотація:

Worldwide, due to the abrupt growth of population, the load demand has been rising dramatically in the last few years. This led to an increase in branch overloads, voltage deviations, and power losses. These problems may result in line outages or the occurrence of blackouts. Flexible AC transmission system (FACTS) devices can be installed in the power system to ensure increased power flow capability and flexible voltage control to address these issues. In this paper, one of the most used FACTS is utilised. It is called Static VAR Compensator (SVC). This controller is one of the most commonly used shunt FACTS controllers due to its low cost in comparison to others, ease of operation, and integration into the power grid. Two Optimization algorithms are combined to form a hybrid optimization approach: Cuckoo Search (CS) and Antlion Optimization (ALO). This hybrid approach employs the exploration of ALO to adjust the optimum allocation and size for SVCs in the power system. This study proposes the IEEE 57 bus scheme as a fairly large structure, with the 50 and 41 branch outages considered the worst-case scenarios for line outages in this system. The simulation results show that the proposed methodology balances exploring the research space and exploiting the best existing solutions compared to some of the other introduced approaches in the literature.

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Moustafa, Ghareeb, Mostafa Elshahed, Ahmed R. Ginidi, Abdullah M. Shaheen, and Hany S. E. Mansour. "A Gradient-Based Optimizer with a Crossover Operator for Distribution Static VAR Compensator (D-SVC) Sizing and Placement in Electrical Systems." Mathematics 11, no. 5 (February 21, 2023): 1077. http://dx.doi.org/10.3390/math11051077.

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A gradient-based optimizer (GBO) is a recently inspired meta-heuristic technique centered on Newton’s gradient-based approach. In this paper, an advanced developed version of the GBO is merged with a crossover operator (GBOC) to enhance the diversity of the created solutions. The merged crossover operator causes the solutions in the next generation to be more random. The proposed GBOC maintains the original Gradient Search Rule (GSR) and Local Escaping Operator (LEO). The GSR directs the search to potential areas and aids in its convergence to the optimal answer, while the LEO aids the searching process in avoiding local optima. The proposed GBOC technique is employed to optimally place and size the distribution static VAR compensator (D-SVC), one of the distribution flexible AC transmission devices (D-FACTS). It is developed to maximize the yearly energy savings via power losses concerning simultaneously different levels of the peak, average, and light loadings. Its relevance is tested on three distribution systems of IEEE 33, 69, and 118 nodes. Based on the proposed GBOC, the outputs of the D-SVCs are optimally varying with the loading level. Furthermore, their installed ratings are handled as an additional constraint relating to two compensation levels of 50% and 75% of the total reactive power load to reflect a financial installation limit. The simulation applications of the proposed GBOC declare great economic savings in yearly energy losses for the three distribution systems with increasing compensation levels and iterations compared to the initial case. In addition, the effectiveness of the proposed GBOC is demonstrated compared to several techniques, such as the original GBO, the salp swarm algorithm, the dwarf mongoose algorithm, differential evolution, and honey badger optimization.

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Rao, B. Venkateswara, and G. V. Nagesh Kumar. "A Comparative Study of BAT and Firefly Algorithms for Optimal Placement and Sizing of Static VAR Compensator for Enhancement of Voltage Stability." International Journal of Energy Optimization and Engineering 4, no. 1 (January 2015): 68–84. http://dx.doi.org/10.4018/ijeoe.2015010105.

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Анотація:

Modern electric power utilities are facing many challenges due to increasing power demand but the growth of power generation and transmission has been limited due to limited resources, environmental restrictions and right-of-way problems. These problems can be minimized by installing Flexible Alternating Current Transmission System (FACTS) devices in modern electric utilities to optimize the existing transmission system. Most effective use of the FACTS devices depend on the fact, how these devices are placed in the power system, i.e. the location and size. An optimal location and size of FACTS devices allows controlling its power flows and thus enhances the stability and reliability of the power systems. In this paper, Firefly Algorithm (FA) and BAT Algorithm (BAT) have been applied and compared to determine the optimal location and size of Static VAR Compensator (SVC) in a power system to improve voltage stability subjected to minimize the active power losses, fuel cost, branching loading and voltage deviation. The effectiveness of the proposed algorithms and improvement of power system stability has been demonstrated on IEEE 57 bus system using fast voltage stability index. The results obtained with variation of parameters of Firefly and BAT Algorithms has been studied and compared with Genetic Algorithm. The results are presented and analyzed.

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Savić, Aleksandar, and Željko Đurišić. "Optimal sizing and location of SVC devices for improvement of voltage profile in distribution network with dispersed photovoltaic and wind power plants." Applied Energy 134 (December 2014): 114–24. http://dx.doi.org/10.1016/j.apenergy.2014.08.014.

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24

Gao, Yang, Changhong Liu, Yuan Liang, Sadegh Kouhestani Hamed, Fuwei Wang, and Bo Bi. "Minimizing Energy Consumption and Powertrain Cost of Fuel Cell Hybrid Vehicles with Consideration of Different Driving Cycles and SOC Ranges." Energies 15, no. 17 (August 25, 2022): 6167. http://dx.doi.org/10.3390/en15176167.

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Hydrogen consumption is an important performance indicator of fuel cell hybrid vehicles (FCHVs). Previous studies have investigated fuel consumption minimization both under different driving cycles and using various power management strategies. However, different constrains on battery state of charge (SOC) ranges can also affect fuel consumption dramatically. In this study, we develop a power-source sizing model based on the Pontryagin’s Minimum Principle (PMP) to minimize the fuel consumption of FCHVs, considering different driving cycles (i.e., FTP-72 and US06) and SOC ranges (conservative 50–60% and aggressive 20–80%). The different driving cycles and SOC ranges present the real-world circumstances of driving FCHVs to some extent. Fuel consumptions are compared both under different driving cycles and using different SOC ranges. The simulation results show an effective power size map, with outlines of an ineffective sizing zone and an inefficient sizing zone based on vehicle performance requirements (e.g., maximum speed and acceleration) and fuel consumption, respectively. Based on the developed model, an optimal power-source size map can be determined while minimizing both fuel consumption and powertrain cost as well as considering different driving cycles and SOC ranges.

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MONDA, Tomoko, and Satoshi SOMIYA. "A Study of Sizing in SMC (2nd Report, Effect of Sizing on Strength)." Transactions of the Japan Society of Mechanical Engineers Series A 71, no. 703 (2005): 551–58. http://dx.doi.org/10.1299/kikaia.71.551.

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26

Cai, Wenlu, Cherdpong Jomdecha, Yingsong Zhao, Li Wang, Shejuan Xie, and Zhenmao Chen. "Quantitative evaluation of electrical conductivity inside stress corrosion crack with electromagnetic NDE methods." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 378, no. 2182 (September 14, 2020): 20190589. http://dx.doi.org/10.1098/rsta.2019.0589.

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This paper presents a comparison of studies on the local distributed electrical conductivity in stress corrosion crack (SCC) from signals of eddy current testing (ECT) and direct current potential drop (DCPD) aiming to improve SCC sizing accuracy when using electromagnetic non-destructive testing (NDT) methods. Experimental setups of ECT and DCPD were established, respectively, to collect measurement signals due to artificial SCCs in a plate of austenitic stainless steel. The local conductivity in the SCC region was reconstructed from the feature parameters extracted from the measured ECT and DCPD signals through inverse analyses. The inversion strategies for ECT and DCPD, each including an efficient forward simulation and an optimization scheme, were introduced from the viewpoint of conductivity reconstruction. Inversion results obtained from the measured ECT and DCPD signals showed the consistent trend which proved the validity of the predicted electrical conductivity indirectly. It is clarified that the electrical conductivity in a SCC is relatively high at the crack tip area and may become as high as 17% of that of the base material. These results provide a good reference to enhance the sizing accuracy of SCC with an electromagnetic NDT method such as ECT by updating the conductive crack model based on the results of this work. This article is part of the theme issue ‘Advanced electromagnetic non-destructive evaluation and smart monitoring’.

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27

Kumar, Anish S., M. Pawan Kumar, Srinivasan Murali, V. Kamakoti, Luca Benini, and Giovanni De Micheli. "A Buffer-Sizing Algorithm for Network-on-Chips with Multiple Voltage-Frequency Islands." Journal of Electrical and Computer Engineering 2012 (2012): 1–12. http://dx.doi.org/10.1155/2012/537286.

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Buffers in on-chip networks constitute a significant proportion of the power consumption and area of the interconnect, and hence reducing them is an important problem. Application-specific designs have nonuniform network utilization, thereby requiring a buffer-sizing approach that tackles the nonuniformity. Also, congestion effects that occur during network operation need to be captured when sizing the buffers. Many NoCs are designed to operate in multiple voltage/frequency islands, with interisland communication taking place through frequency converters. To this end, we propose a two-phase algorithm to size the switch buffers in network-on-chips (NoCs) considering support for multiple-frequency islands. Our algorithm considers both the static and dynamic effects when sizing buffers. We analyze the impact of placing frequency converters (FCs) on a link, as well as pack and send units that effectively utilize network bandwidth. Experiments on many realistic system-on-Chip (SoC) benchmark show that our algorithm results in 42% reduction in amount of buffering when compared to a standard buffering approach.

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28

Liu, Kenan, Bugong Sun, Xiaoyang Gao, Yang Zhang, Wei Sun, Quan Feng, and Wanxia Yang. "Optimal Sizing of the Stand-Alone Photovoltaic System for a Solar-Powered Translational Sprinkler Irrigation Machine considering the Loss of Power Supply Probability." Mathematical Problems in Engineering 2022 (January 19, 2022): 1–10. http://dx.doi.org/10.1155/2022/6133969.

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The translational sprinkler irrigation machine is widely used because of its high degree of automation, less manual investment, and convenient movement. However, when using the sprinkler irrigation machine, the power supply is difficult to be guaranteed in some remote power shortage areas. Solar energy has become one of the best choices for the power source of sprinkler irrigation machines. An important issue is the optimal sizing of the stand-alone photovoltaic system for a solar-powered translational sprinkler irrigation machine. This work conducts the optimal sizing of the stand-alone photovoltaic system for a solar-powered translational sprinkler irrigation machine considering the loss of power supply probability. Firstly, the self-developed translational sprinkler irrigation machine is introduced. The load power, which includes the driving power of the translational sprinkler irrigation machine, water intake pressure driving power, and the loss power of the controller and sensors, is considered in the calculation process. Subsequently, the photovoltaic generator model and the battery storage model are established. Then, the stand-alone photovoltaic system is optimized considering the loss of power supply probability (LPSP) and the life cycle cost (LCC). After the solar irradiance and ambient temperature of a typical sunny day in the test area are given, the optimal combination of the PV module and battery is obtained. The optimal sizing result is verified using the PV power, state of charge (SOC), and load power. The presented optimal sizing method is also compared with an existing method. Besides, the operation test of the sprinkler irrigation machine is also carried out to verify the optimal sizing result. The optimal sizing result is proved to be effective and applicable.

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Azeem, Fawad, Ashfaq Ahmad, Taimoor Muzaffar Gondal, Jehangir Arshad, Ateeq Ur Rehman, Elsayed M. Tag Eldin, Muhammad Shafiq, and Habib Hamam. "Load Management and Optimal Sizing of Special-Purpose Microgrids Using Two Stage PSO-Fuzzy Based Hybrid Approach." Energies 15, no. 17 (September 5, 2022): 6465. http://dx.doi.org/10.3390/en15176465.

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The sizing of microgrids depends on the type of load and its operational hours. The significance of understanding the load operational characteristics in special purpose islanded microgrids is much needed for economic system sizing. The load operation of special-purpose microgrids often consumes high power for a short duration and remains idle most of the time, thus reducing the load factor. The inclusion of such loads in microgrid sizing causes huge capital costs making islanded microgrids an unfeasible solution. The islanded microgrid under study is an agricultural microgrid in a village having a small Crab Processing Plant (CPP) and a Domestic Sector (DS). The CPP constitutes the major power consumption. The community has a unique load consumption trend that is dependent on the highly uncertain parameter of availability of the crabs. Interestingly, crab availability is an independent parameter and cannot be accurately scheduled. The existing system sizing of the microgrid is performed based on the conventional methods that consider the CPP for full-day operation. However, the microgrid sources, especially the storage system may be reflected as oversized if the crab processing plants do not operate for several days due to the uncertain behavior of CPP causing enormous power wastage. In this paper, an integrated fixed and operational mode strategy for uncertain heavy loads is formulated. The proposed algorithm is based on the optimal sizing methodology aided by the load scheduling control strategy. The Particle Swarm Optimization technique is used for the optimal sizing integrated with the fuzzy logic controller to manage the available load. The membership functions are available excess power and the state of the charge of storage that defines the operational conditions for CPP. Based on input membership functions, the fuzzy controller decides on power dispatch in DS or CPP, keeping considerable SoC available for night hours. The simulation result shows that the time-dependent fuzzy controller approach manages to provide power to both sectors under optimal sizing while reducing the overall cost by 24% less than the existing microgrid.

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30

Milićević, Stefan, and Ivan Blagojević. "Component sizing and energy management for a series hybrid electric tracked vehicle." Vojnotehnicki glasnik 70, no. 4 (2022): 877–96. http://dx.doi.org/10.5937/vojtehg70-39762.

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Introduction/purpose: The paper presents a systematic approach to the development of a series hybrid electric tracked vehicle (HETV) including powertrain sizing and adequate energy management strategy (EMS) selection. Methods: Powertrain elements were sized considering key performance requirements. Three energy management strategies were proposed: Thermostat Control Strategy (TCS), Power Follower Control Strategy (PFCS), and Optimal Power Source Strategy (OPSS). The evaluation of the powertrain configuration and the three proposed EMSs was performed in the Simulink environment using a driving cycle containing significant acceleration, braking and steering. Results: The results showed that the OPSS proved to be the best due to increased fuel economy and a low battery state of charge (SOC) variation. Compared to the previous research of the same vehicle with a parallel hybrid configuration, significantly better results were achieved. The investigation of the results indicates that the proposed powertrain and control strategy offer 53.79% better fuel economy which indicates that the powertrain sizing was properly performed. Conclusions: The results of this work are of great importance for understanding the effect of proper powertrain sizing on fuel economy. Compared to the reference vehicle, the proposed configuration achieves significant improvement, most of which is attributed to adequate sizing. The OPSS proved to be the best strategy, thus confirming the theoretical hypothesis. The series hybrid configuration with the OPSS as the EMS proved to be a major candidate for use in HETVs.

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31

Aleid, L., and P. Pilidis. "Variable cycle jet engines for a Mach 2·7 supersonic civil transport." Aeronautical Journal 102, no. 1011 (January 1998): 31–36. http://dx.doi.org/10.1017/s0001924000065714.

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AbstractThe aim of the work outlined in this paper is to compare three different variable cycle jet engine concepts for future SSTs. These engines are: the turbofan-turbojet, the mid-tandem fan engine and the double bypass engine. The comparison is carried out on the basis of unin-stalled and installed performance, handling and sizing issues.This preliminary analysis compares SFC, size, variable geometry and cycle changes for each engine. The installed performance was estimated by calculating the air friction, the pre-entry and the afterbody drags, together with the wave drag due to the shock waves. A sizing calculation was carried out for the whole nacelle. The uninstalled and installed fuel bill, for two standard missions, is also estimated.These preliminary results indicate that the turbofan-turbojet and the mid-tandem fan engines are quite similar in terms of general suitability. The mid-tandem fan appears to be an attractive proposition from the point of view of sizing, however, this comes with a small penalty in fuel consumption. The present double bypass engine was found to be the least attractive for the application, although the differences are small.

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32

Wu, De Hui, Zhong Yuan Zhang, Zhen Liang Liu, and Xiao Hao Xia. "3-D Simulation of Remote Field Eddy Current Detection for Stress Corrosion Cracks in Pipeline." Advanced Materials Research 760-762 (September 2013): 1154–58. http://dx.doi.org/10.4028/www.scientific.net/amr.760-762.1154.

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Three-dimensional (3-D)finite element simulation models are conducted to simulate the in-serviceinspection of the axial stress corrosion cracking (SCC) in ferromagneticpipeline using remote field eddy current (RFEC) probes. In this paper, atypical remote field eddy current probe which is internal to and coaxial withthe pipe is firstly introduced. Then a 3-D finite element simulation model isestablished in ANSYS to analyze the detection of RFEC technology. Finally theRFEC signals are observed when changing the geometric parameters, and thedefinite influences of crack size on the amplitude and phase lag of REFCsignals are evaluated. The results of the investigations are beneficial to thedetection and sizing of SCC in pipelines

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33

Li, Xiu Qian, Hai Peng Qiu, Jian Jiao, Jing Hua Luo, and Yu Wang. "Effect of Interfacial Treatment Process on the Microstructure and Properties of C_f/SiC Ceramic Matrix Composites." Key Engineering Materials 519 (July 2012): 277–80. http://dx.doi.org/10.4028/www.scientific.net/kem.519.277.

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Abstract. This paper investigated the Cf/SiC ceramic matrix composites. By utilizing different interfacial treatment processes to prepare carbon-fiber preform, the preform was then densified by infiltration and pyrolysis(PIP) with polycarbosilan/xylene solution as precursor, and the Cf/SiC ceramic matrix composite specimens were fabricated. Mechanical tests such as bending test and fracture toughness were performed for Cf/SiC samples. The results show that the interfacial bonding strength in the sample with high-temperature treatment process was improved due to removing surface sizing. The samples which were treated up to 1400°C exhibited the highest three-point flexural strength, up to 595MPa; The samples which were treated up to 1400°C and deposited by pyrolytic carbon(PyC) coating shows the highest fracture toughness value which was 20.70MPa•m1/2.

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34

IUCHI, Keiji, and Satoshi SOMIYA. "The effect of sizing on fatigue residual strength on SMC." Proceedings of the JSME annual meeting 2000.1 (2000): 573–74. http://dx.doi.org/10.1299/jsmemecjo.2000.1.0_573.

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35

Sharma, Sidharth, Anna Engelmann, Admela Jukan, and Ashwin Gumaste. "VNF Availability and SFC Sizing Model for Service Provider Networks." IEEE Access 8 (2020): 119768–84. http://dx.doi.org/10.1109/access.2020.3005287.

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36

Alizadeh, Seyed Morteza, Sakineh Sadeghipour, Cagil Ozansoy, and Akhtar Kalam. "Developing a Mathematical Model for Wind Power Plant Siting and Sizing in Distribution Networks." Energies 13, no. 13 (July 6, 2020): 3485. http://dx.doi.org/10.3390/en13133485.

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Wind Power Plants (WPPs) are generally located in remote areas with weak distribution connections. Hence, the value of Short Circuit Capacity (SCC), WPP size and the short circuit impedance angle ratio (X/R) are all very critical in the voltage stability of a distribution system connected WPP. This paper presents a new voltage stability model based on the mathematical relations between voltage, the level of wind power penetration, SCC and X/R at a given Point of Common Coupling (PCC) of a distribution network connected WPP. The proposed model introduces six equations based on the SCC and X/R values seen from a particular PCC point. The equations were developed for two common types of Wind Turbine Generators (WTGs), including: the Induction Generator (IG) and the Double Fed Induction Generator (DFIG). Taking advantage of the proposed equations, design engineers can predict how the steady-state PCC voltage will behave in response to different penetrations of IG- and DFIG-based WPPs. In addition, the proposed equations enable computing the maximum size of the WPP, ensuring grid code requirements at the given PCC without the need to carry out complex and time-consuming computational tasks or modelling of the system, which is a significant advantage over existing WPP sizing approaches.

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37

Mejía-Giraldo, Diego, Gregorio Velásquez-Gomez, Nicolás Muñoz-Galeano, Juan Cano-Quintero, and Santiago Lemos-Cano. "A BESS Sizing Strategy for Primary Frequency Regulation Support of Solar Photovoltaic Plants." Energies 12, no. 2 (January 20, 2019): 317. http://dx.doi.org/10.3390/en12020317.

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This paper proposes a strategy for sizing a battery energy storage system (BESS) that supports primary frequency regulation (PFR) service of solar photo-voltaic plants. The strategy is composed of an optimization model and a performance assessment algorithm. The optimization model includes not only investment costs, but also a novel penalty function depending on the state of charge (SoC). This function avoids the existence of a potential inappropriate SoCtrajectory during BESS operation that could impede the supply of PFR service. The performance assessment algorithm, fed by the optimization model sizing results, allows the emulation of BESS operation and determines either the success or failure of a particular BESS design. The quality of a BESS design is measured through number of days in which BESS failed to satisfactorily provide PFR and its associated penalization cost. Battery lifetime, battery replacements, and SoC are also key performance indexes that finally permit making better decisions in the election of the best BESS size. The inclusion of multiple BESS operational restrictions under PFR is another important advantage of this strategy since it adds a realistic characterization of BESS to the analysis. The optimization model was coded using GAMS/CPLEX, and the performance assessment algorithm was implemented in MATLAB. Results were obtained using actual frequency data obtained from the Colombian power system; and the resulting BESS sizes show that the number of BESS penalties, caused by failure to provide PFR service, can be reduced to zero at minimum investment cost.

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38

IUCHI, Keiji, and Satoshi SOMIYA. "K-0930 Influence amount of sizing for strand-shape in SMC." Proceedings of the JSME annual meeting V.01.1 (2001): 93–94. http://dx.doi.org/10.1299/jsmemecjo.v.01.1.0_93.

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39

Nguyen-Huu, Thien-An, Van Thang Nguyen, Kyeon Hur, and Jae Woong Shim. "Coordinated Control of a Hybrid Energy Storage System for Improving the Capability of Frequency Regulation and State-of-Charge Management." Energies 13, no. 23 (November 29, 2020): 6304. http://dx.doi.org/10.3390/en13236304.

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The paper proposes a coordinated operation method of two independent storages for managing state-of-charge (SOC) and for providing ancillary service concerning frequency regulation (FR); furthermore, this article also introduces the power allocation scheme between two storages in consideration of the coverage of the frequency band for each storage along with the SOC management scheme of the supercapacitor and battery. We also provide a guideline for the storage sizing on the basis of the smoothing time constant. Additionally, we verify the advantage of the HESS in extending the lifetime of the battery, which is estimated by a real-time state-of-health (SOH) calculation method. The Bode plot of the proposed method is analyzed to observe the power spectrum coverage in the frequency domain through the case studies using PSCAD/EMTDC and MATLAB.

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40

Kumar, Chandan, Rongwu Zhu, Giampaolo Buticchi, and Marco Liserre. "Sizing and SOC Management of a Smart-Transformer-Based Energy Storage System." IEEE Transactions on Industrial Electronics 65, no. 8 (August 2018): 6709–18. http://dx.doi.org/10.1109/tie.2017.2784389.

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41

Li, Zongjian, Jun Wang, Bing Ji, and Z. John Shen. "Power Loss Model and Device Sizing Optimization of Si/SiC Hybrid Switches." IEEE Transactions on Power Electronics 35, no. 8 (August 2020): 8512–23. http://dx.doi.org/10.1109/tpel.2019.2954288.

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42

ABE, Shihomi, and Wataru NAKAO. "J0405-5-4 Increase in speed of self-crack healing ofAl_2O_3/SiC composite by SiC nano sizing." Proceedings of the JSME annual meeting 2009.6 (2009): 399–400. http://dx.doi.org/10.1299/jsmemecjo.2009.6.0_399.

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43

Espinasse, Benjamin, Manali Joglekar, Giancarlo Valiente, and Gowthami M. Arepally. "Novel Techniques for Measurement of Variable Sized PF4/H Complexes." Blood 120, no. 21 (November 16, 2012): 2204. http://dx.doi.org/10.1182/blood.v120.21.2204.2204.

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Abstract Abstract 2204 Electrostatic interactions between Platelet factor 4 (PF4), a cationic protein, and heparin, an anionic carbohydrate result in the formation of ultra-large complexes (ULCs) that are immunogenic in mice (Suvarna, Blood 2007) and contribute to the immune pathogenesis of Heparin-induced thrombocytopenia (HIT). Previous studies (Rauova, Blood 2005; Greinacher, Arterioscler Thromb Vasc Biol, 2006) have shown that the size of ULCs is determined by the concentration and the molar ratios of PF4:H (PHRs) of each compound. Size determination of PF4/H complexes has been problematic due to technical limitations of two commonly employed methods for sizing complexes, photon correlation spectroscopy (PCS) and size exclusion chromatography (SEC). PCS is a technique for measuring particles in solution using laser illumination is based on principles of Brownian motion. PCS performs optimally with monodisperse populations and is biased by the presence of large aggregates. SEC, a liquid chromatography method, is technically cumbersome, requires sample labeling and not feasible for measuring large numbers of samples. To address these limitations, we examined two novel approaches for measuring a broad range of PF4/H complex size (100–3000 nm) in vitro: Nanosight and flow cytometry (FC). Nanosight (Nanosight Ltd, Wiltshire, United Kingdom),was employed for measuring small-sized complexes using physiologic concentrations of hPF4 (10 ug/mL). Nanosight uses proprietary software to track nanoparticles (range 10–1000nm) in solution by laser illumination with real-time tracking of the motion of individual particles by a camera. Analysis parameters provided by the software include: 1) Particle size distributions displayed as histograms 2) direct visualization of particles 3) particle counting and sizing and 4) particle scatter intensity vs. count and size. For measuring intermediate to large sized particles, formed at high hPF4 concentrations (95 ug/mL), we used flow cytometry calibrated with sizing beads on side scatter channel (SSC). FC was performed using a BD LSRII cell analyzer (Becton Dickinson, Franklin Lakes, NJ), a high throughput flow analyzer with the threshold channel for SSC set to 200 and a flow rate of 1 ul per second. The instrument was calibrated using sizing beads ranging from 0.3–6 μm in size (Figure A). For both techniques, PF4/H ULCs were formed by adding hPF4 (10 or 95 ug/mL)and various UFH concentrations in HBSS to yield the indicated PHRs. Complexes were incubated for 60 minutes and measured by NanoSight or FC. Results of experiments using Nanosight are shown in Table 1 with results showing size and particle counts for each PHR. Results of FC are shown in Figure B and Table 2 (median, 5% and 95% size in nm). Both studies showed reproducibility for measurements for a given concentration and showed changes in complex size as a function of PHR (Figure B). Both methodologies are technically simple and provide complementary approaches to PCS for PF4/H complex size determination. Disclosures: No relevant conflicts of interest to declare.

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44

V, Shreya. "Comparative Study on SOC Estimation Techniques for Optimal Battery Sizing for Hybrid Vehicles." International Journal on Recent and Innovation Trends in Computing and Communication 3, no. 4 (2015): 1957–63. http://dx.doi.org/10.17762/ijritcc2321-8169.150444.

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45

Comte, E., D. Merhi, V. Michaud, and J. A. E. Månson. "Void formation and transport during SMC manufacturing: Effect of the glass fiber sizing." Polymer Composites 27, no. 3 (2006): 289–98. http://dx.doi.org/10.1002/pc.20193.

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46

Fan, Fulin, Giorgio Zorzi, David Campos-Gaona, Graeme Burt, Olimpo Anaya-Lara, John Nwobu, and Ander Madariaga. "Sizing and Coordination Strategies of Battery Energy Storage System Co-Located with Wind Farm: The UK Perspective." Energies 14, no. 5 (March 6, 2021): 1439. http://dx.doi.org/10.3390/en14051439.

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The rapid development and growth of battery storage have heightened an interest in the co-location of battery energy storage systems (BESS) with renewable energy projects which enables the stacking of multiple revenue streams while reducing connection charges of BESS. To help wind energy industries better understand the coordinated operation of BESS and wind farms and its associated profits, this paper develops a simulation model to implement a number of coordination strategies where the BESS supplies enhanced frequency response (EFR) service and enables the time shift of wind generation based on the UK perspective. The proposed model also simulates the degradation of Lithium-Ion battery and incorporates a state of charge (SOC) dependent limit on the charge rate derived from a constant current-constant voltage charging profile. In addition, a particle swarm optimisation-based battery sizing algorithm is developed here on the basis of the simulation model to determine the optimal size of the co-located BESS along with SOC-related strategy variables that maximise the net present value of the wind + BESS system at the end of the EFR contract.

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47

Worighi, Imane, Thomas Geury, Mohamed El Baghdadi, Joeri Van Mierlo, Omar Hegazy, and Abdelilah Maach. "Optimal Design of Hybrid PV-Battery System in Residential Buildings: End-User Economics, and PV Penetration." Applied Sciences 9, no. 5 (March 12, 2019): 1022. http://dx.doi.org/10.3390/app9051022.

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This paper proposes an optimal design for hybrid grid-connected Photovoltaic (PV) Battery Energy Storage Systems (BESSs). A smart grid consisting of PV generation units, stationary Energy Storage Systems (ESSs), and domestic loads develops a multi-objective optimization algorithm. The optimization aims at minimizing the Total Cost of Ownership (TCO) and the Voltage Deviation (VD) while considering the direct and indirect costs for the prosumer, and the system stability with regard to intermittent PV generation. The optimal solution for the optimization of the PV-battery system sizing with regard to economic viability and the stability of operation is found while using the Genetic Algorithm (GA) with the Pareto front. In addition, a fuzzy logic-based controller is developed to schedule the charging and discharging of batteries while considering the technical and economic aspects, such as battery State of Charge (SoC), voltage profile, and on/off-peak times to shave the consumption peaks. Thus, a hybrid approach that combines a Fuzzy Logic Controller (FLC) and the GA is developed for the optimal sizing of the combined Renewable Energy Sources (RESs) and ESSs, resulting in reductions of approximately 4% and 17% for the TCO and the VD, respectively. Furthermore, a sensitivity cost-effectiveness analysis of the complete system is conducted to highlight and assess the profitability and the high dependency of the optimal system configuration on battery prices.

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Ahmad, Husam, Jonas Stiller, Erik Päßler, Daisy Nestler, Guntram Wagner, and Lothar Kroll. "Influence of Initial Fibre Length and Content Used in the Injection Moulding of CFRP on the Properties of C/C and C/C-SiC Composites." Key Engineering Materials 809 (June 2019): 171–79. http://dx.doi.org/10.4028/www.scientific.net/kem.809.171.

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The production of C/C-SiC composites comprises a three-stage process: forming (CFRP-composite), pyrolysis (C/C-composite) and liquid silicon infiltration (C/C-SiC). A new promising approach for the manufacturing of CFRP intermediate composites is the injection moulding of customised granulates (novolac resin, hardener, processing additives and short carbon fibre) produced by compounding technique. To date, a direct dosing of short carbon fibre into the compounder was technically not realisable due to fibre separation and electrostatic charging in the hopper. A possible substitute solution has been the direct feeding of a carbon fibre bundle from a roving into the compounder. However, this is associated with a severe damage of the fibres and an inaccurate adjustment of the fibres content. In the present article, new chopped carbon fibres provided with an adapted sizing to be directly dosed into the compounder are used. The fibres possess a predefined length of 3 and 6 mm and their content amounts to 50 and 58 wt.%. The influence of the initial fibre length and fibre content on the physical and mechanical properties of the resulting CFRP-, C/C-and C/C-SiC-composites is presented and discussed. In addition, the impact of fibre feeding procedure at the compounding stage on the microstructure is considered

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49

Beyoud, Abdelkader, and Ahmed Bouhaouss. "An investigation into the feasibility of a hybrid generator–photovoltaic–wind farm with variable load profile: case of headland south-west of Morocco." Clean Energy 6, no. 3 (June 1, 2022): 484–95. http://dx.doi.org/10.1093/ce/zkac025.

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Abstract A hybrid system proposed by three different specifications for the equipment of a tourist lodge in the headland of south-west Morocco was sized by analysing the limits of load profile constraints, such as hour-to-hour variability (HHR), day-to-day variability (DDR) and the operating reserve rate (ROR). Based on the three-factor Doehlert matrix recommendations, the simulations employed an energy-sizing tool for hybrid renewable-energy systems. Testing was conducted with DDR at 5–30%, HHR at 10–30% and ROR at 0–20%. Under these conditions, a second-order polynomial relationship with a correlation rate of ~90% was found between the net present cost (NPC) of the system, the levelized cost of electricity and the various constraint factors. The first specification, SPC(1), composed of generators and batteries, was introduced to control and validate the simulation independently of renewable energy, which showed a positive manifestation with the imposed constraints. The analysis expanded by introducing solar and wind energy resources. The SPC(2) configuration added PV modules to the SPC(1) and the SPC(3) configuration added wind turbines to SPC(2). The effect of DDR, HHR and ROR in the trials was significant by linear regression. At the same time, only DDR had a significant quadratic regression. The others, with their pairwise interactions, were insignificant. The desirability procedure made it possible to calculate the maximum limits of load profile constraint variables leading to targets of LCOE = 0.41 US$/kWh and NPC = US$320 080.1 of the load profile constraints: the DDR = 15.47% and the HHR = 26.55% at an ROR rate of 17.77%.

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Bai, Na, Rui Xing Li, Zhan Li Gong, and Shou Biao Tan. "A High Robust SRAM Bitcell under Optimum-Energy Supply Voltage." Applied Mechanics and Materials 121-126 (October 2011): 1332–37. http://dx.doi.org/10.4028/www.scientific.net/amm.121-126.1332.

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Simulation results illustrate that there is an optimum-energy supply voltage point (Vopt) for SoC. And these voltage points normally lie in weak sub-threshold or near-threshold region. Considering about the degraded robustness under this low supply voltage, structural change instead of the sizing change is considered in proposed design. Different from conventional 6T SRAM design, the trip point voltage of proposed design changes according to bit-line voltage values. In this way, its read margin is 45% greater than conventional 6T SRAM. The proposed bit-cell exhibits wide hysteresis effect, making the design less vulnerable to process variation. Its hold margin is 30.2% greater than conventional 6T SRAM. The optimum-energy supply voltage of proposed array (256×16) is 400 mV. At the same time, the power consumption at 400 mV decreases to 16% compared to that at 1200 mV.

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