A method of enhancing power system stability for a single machine to infinite bus power system is presented. The technique used compromises the effectiveness of Proportional-Integral-Derivative controller （PID）. In ...A method of enhancing power system stability for a single machine to infinite bus power system is presented. The technique used compromises the effectiveness of Proportional-Integral-Derivative controller （PID）. In order to satisfy the damping characteristics for the proposed power system over a wide range of operating interval, rotational speed, torque angle and terminal voltage signals of the synchronous machine are utilized as control signals of the system. It is well known that these variables have significant effects on damping the generators shaft mechanical oscillations, it＇ll be so easy to validate the most suitable controller as seen from the simulation results.展开更多
Suppression of the dynamic oscillations of tie-line power exchanges and frequency in the affected interconnected power systems due to loading-condition changes has been assigned as a prominent duty of automatic genera...Suppression of the dynamic oscillations of tie-line power exchanges and frequency in the affected interconnected power systems due to loading-condition changes has been assigned as a prominent duty of automatic generation control(AGC). To alleviate the system oscillation resulting from such load changes, implementation of flexible AC transmission systems(FACTSs) can be considered as one of the practical and effective solutions. In this paper, a thyristor-controlled series compensator(TCSC), which is one series type of the FACTS family, is used to augment the overall dynamic performance of a multi-area multi-source interconnected power system. To this end, we have used a hierarchical adaptive neuro-fuzzy inference system controller-TCSC(HANFISC-TCSC) to abate the two important issues in multi-area interconnected power systems, i.e., low-frequency oscillations and tie-line power exchange deviations. For this purpose, a multi-objective optimization technique is inevitable. Multi-objective particle swarm optimization(MOPSO) has been chosen for this optimization problem, owing to its high performance in untangling non-linear objectives. The efficiency of the suggested HANFISC-TCSC has been precisely evaluated and compared with that of the conventional MOPSO-TCSC in two different multi-area interconnected power systems, i.e., two-area hydro-thermal-diesel and three-area hydro-thermal power systems. The simulation results obtained from both power systems have transparently certified the high performance of HANFISC-TCSC compared to the conventional MOPSO-TCSC.展开更多
Quickly getting back the synchronism of a disturbed interconnected multi-area power system due to variations in loading condition is recognized as prominent issue related to automatic generation control(AGC).In this r...Quickly getting back the synchronism of a disturbed interconnected multi-area power system due to variations in loading condition is recognized as prominent issue related to automatic generation control(AGC).In this regard,AGC system based on fuzzy logic,i.e.,so-called FLAGC can introduce an effectual performance to suppress the dynamic oscillations of tie-line power exchanges and frequency in multi-area interconnected power system.Apart from that,simultaneous coordination scheme based on particle swarm optimization(PSO)along with real coded genetic algorithm(RCGA)is suggested to coordinate FLAGCs of the all areas.To clarify the high efficiency of aforementioned strategy,two different interconnected multi-area power systems,i.e.,three-area hydro-thermal power system and five-area thermal power system have been taken into account for relevant studies.The potency of this strategy has been thoroughly dealt with by considering the step load perturbation(SLP)in both the under study power systems.To sum up,the simulation results have plainly revealed dynamic performance of FLAGC as compared with conventional AGC(CAGC)in each power system in order to damp out the power system oscillations.展开更多
voltage direct current(HVDC)transmission lines are being constructed throughout the world,aided by advancements in power electronics and the potential value to transfer power between distant areas and off-shore locati...voltage direct current(HVDC)transmission lines are being constructed throughout the world,aided by advancements in power electronics and the potential value to transfer power between distant areas and off-shore locations.Multiple HVDC lines within and across large AC interconnections could bring about economic benefits such as interregional capacity exchange and transfer of low-cost,distant electric energy directly to load centers.In addition,network configuration of HVDC lines could result in additional benefits that have not been deeply studied.This paper describes the modeling process for continentallevel power system interconnections with the addition of multiple HVDC lines configured as a macrogrid.The models used for study are based on industry-accepted power-flow and dynamic system models for the North American Eastern and Western Interconnections.The model provides insight on feasibility and initial steady-state and stability tests of the HVDC macrogrid and its interactions with the existing electricity infrastructure,opening the door to analysis of the technical value of such a macrogrid.展开更多
The Brazilian transmission system is facing challenging problems with the distance between its generation areas and consumer centers that will be partly solved by the use of HVDC point-to-point systems.In the near fut...The Brazilian transmission system is facing challenging problems with the distance between its generation areas and consumer centers that will be partly solved by the use of HVDC point-to-point systems.In the near future,the southeast subsystem will have a large amount of power injected through HVDC Systems in multiple points with relatively close electrical proximity.Therefore,the effects of a multi-infeed system are expected to influence the performance and operation of the network.Extensive studies and simulations will play an important role in determining the extension of the interactions among HVDC converters and determine if such interactions cause multiple commutation failures,thus disturbing the dynamic stability of the system.The use of CCC(Capacitor Commutated Converter)HVDC systems will also be assessed and is expected to diminish the need for a strong AC network(high short circuit level)and,therefore,mitigate multi-infeed interactions.The southeast subsystem of the Brazilian Power System currently has four LCC inverters,two of them belong to the Madeira power plant and the other two are from the Itaipu power plant.By the year 2024,four other HVDC systems will be arriving in the same region.This paper discusses the HVDC multi-infeed phenomena regarding the relevance of using synchronous machine models to represent important power plants and the application of mitigation methods regarding the 2020 network model,where six HVDC links will be present.展开更多
文摘A method of enhancing power system stability for a single machine to infinite bus power system is presented. The technique used compromises the effectiveness of Proportional-Integral-Derivative controller （PID）. In order to satisfy the damping characteristics for the proposed power system over a wide range of operating interval, rotational speed, torque angle and terminal voltage signals of the synchronous machine are utilized as control signals of the system. It is well known that these variables have significant effects on damping the generators shaft mechanical oscillations, it＇ll be so easy to validate the most suitable controller as seen from the simulation results.
文摘Suppression of the dynamic oscillations of tie-line power exchanges and frequency in the affected interconnected power systems due to loading-condition changes has been assigned as a prominent duty of automatic generation control(AGC). To alleviate the system oscillation resulting from such load changes, implementation of flexible AC transmission systems(FACTSs) can be considered as one of the practical and effective solutions. In this paper, a thyristor-controlled series compensator(TCSC), which is one series type of the FACTS family, is used to augment the overall dynamic performance of a multi-area multi-source interconnected power system. To this end, we have used a hierarchical adaptive neuro-fuzzy inference system controller-TCSC(HANFISC-TCSC) to abate the two important issues in multi-area interconnected power systems, i.e., low-frequency oscillations and tie-line power exchange deviations. For this purpose, a multi-objective optimization technique is inevitable. Multi-objective particle swarm optimization(MOPSO) has been chosen for this optimization problem, owing to its high performance in untangling non-linear objectives. The efficiency of the suggested HANFISC-TCSC has been precisely evaluated and compared with that of the conventional MOPSO-TCSC in two different multi-area interconnected power systems, i.e., two-area hydro-thermal-diesel and three-area hydro-thermal power systems. The simulation results obtained from both power systems have transparently certified the high performance of HANFISC-TCSC compared to the conventional MOPSO-TCSC.
文摘Quickly getting back the synchronism of a disturbed interconnected multi-area power system due to variations in loading condition is recognized as prominent issue related to automatic generation control(AGC).In this regard,AGC system based on fuzzy logic,i.e.,so-called FLAGC can introduce an effectual performance to suppress the dynamic oscillations of tie-line power exchanges and frequency in multi-area interconnected power system.Apart from that,simultaneous coordination scheme based on particle swarm optimization(PSO)along with real coded genetic algorithm(RCGA)is suggested to coordinate FLAGCs of the all areas.To clarify the high efficiency of aforementioned strategy,two different interconnected multi-area power systems,i.e.,three-area hydro-thermal power system and five-area thermal power system have been taken into account for relevant studies.The potency of this strategy has been thoroughly dealt with by considering the step load perturbation(SLP)in both the under study power systems.To sum up,the simulation results have plainly revealed dynamic performance of FLAGC as compared with conventional AGC(CAGC)in each power system in order to damp out the power system oscillations.
基金This work was supported by the Pacific Northwest National Laboratory operated by Battelle for the U.S.Department of Energy under contract DE-AC05-76RL01830.
文摘voltage direct current(HVDC)transmission lines are being constructed throughout the world,aided by advancements in power electronics and the potential value to transfer power between distant areas and off-shore locations.Multiple HVDC lines within and across large AC interconnections could bring about economic benefits such as interregional capacity exchange and transfer of low-cost,distant electric energy directly to load centers.In addition,network configuration of HVDC lines could result in additional benefits that have not been deeply studied.This paper describes the modeling process for continentallevel power system interconnections with the addition of multiple HVDC lines configured as a macrogrid.The models used for study are based on industry-accepted power-flow and dynamic system models for the North American Eastern and Western Interconnections.The model provides insight on feasibility and initial steady-state and stability tests of the HVDC macrogrid and its interactions with the existing electricity infrastructure,opening the door to analysis of the technical value of such a macrogrid.
基金This research was supported by ANEEL(Brazilian Energy Regulatory Agency)and the State Grid Brazilian Holding,as well as the University of Sao Paulo.
文摘The Brazilian transmission system is facing challenging problems with the distance between its generation areas and consumer centers that will be partly solved by the use of HVDC point-to-point systems.In the near future,the southeast subsystem will have a large amount of power injected through HVDC Systems in multiple points with relatively close electrical proximity.Therefore,the effects of a multi-infeed system are expected to influence the performance and operation of the network.Extensive studies and simulations will play an important role in determining the extension of the interactions among HVDC converters and determine if such interactions cause multiple commutation failures,thus disturbing the dynamic stability of the system.The use of CCC(Capacitor Commutated Converter)HVDC systems will also be assessed and is expected to diminish the need for a strong AC network(high short circuit level)and,therefore,mitigate multi-infeed interactions.The southeast subsystem of the Brazilian Power System currently has four LCC inverters,two of them belong to the Madeira power plant and the other two are from the Itaipu power plant.By the year 2024,four other HVDC systems will be arriving in the same region.This paper discusses the HVDC multi-infeed phenomena regarding the relevance of using synchronous machine models to represent important power plants and the application of mitigation methods regarding the 2020 network model,where six HVDC links will be present.
