This paper proposes a coordinated switching power system stabilizer(SPSS)to enhance the stability of multimachine power systems.The SPSS switches between a bang-bang power system stabilizer(BPSS)and a conventional pow...This paper proposes a coordinated switching power system stabilizer(SPSS)to enhance the stability of multimachine power systems.The SPSS switches between a bang-bang power system stabilizer(BPSS)and a conventional power system stabilizer(CPSS)based on a state-dependent switching strategy.The BPSS is designed as a bang-bang constant funnel controller(BCFC).It is able to provide fast damping of rotor speed oscillations in a bang-bang manner.The closed-loop stability of the power system controlled by the SPSSs and the CPSSs is analyzed.To verify the control performance of the SPSS,simulation studies are carried out in a 4-generator 11-bus power system and the IEEE 16-generator 68-bus power system.The damping ability of the SPSS is evaluated in aspects of small-signal oscillation damping and transient stability enhancement,respectively.Meanwhile,the coordination between different SPSSs and the coordination between the SPSS and the CPSS are investigated therein.展开更多
This paper presented a novel wide-area nonlinear excitation control strategy for multi-machine power systems. A simple and effective model transformation method was proposed for the system's mathematical model in ...This paper presented a novel wide-area nonlinear excitation control strategy for multi-machine power systems. A simple and effective model transformation method was proposed for the system's mathematical model in the COI (center of inertia) coordinate system. The system was transformed to an uncertain linear one where deviation of generator terminal voltage became one of the new state variables. Then a wide-area nonlinear robust voltage controller was designed utilizing a LMI (linear matrix inequality) based robust control theory. The proposed controller does not rely on any preselected system operating point, adapts to variations of network parameters and system operation conditions, and assures regulation accuracy of generator terminal voltages. Neither rotor angle nor any variable's differentiation needs to be measured for the proposed controller, and only terminal voltages, rotor speeds, active and reactive power outputs of generators are required. In addition, the proposed controller not only takes into account time delays of remote signals, but also eliminates the effect of wide-area information's incompleteness when not all generators are equipped with PMU (phase measurement unit). Detailed tests were conducted by PSCAD/EMTDC for a three-machine and four-machine power systems respectively, and simulation results illustrate high performance of the proposed controller.展开更多
In this paper we construct an energy function for multi-machine power systems with doubly-fed induction generator-based wind turbine(DFIGWT)according to a synchronous-generator-mimicking(SGM)model of the DFIGWT.An SGM...In this paper we construct an energy function for multi-machine power systems with doubly-fed induction generator-based wind turbine(DFIGWT)according to a synchronous-generator-mimicking(SGM)model of the DFIGWT.An SGM model is proposed to approximate the dynamics of a DFIGWT.Similar to the modelling of a synchronous generator(SG),the internal dynamics of a DFIGWT are also described with differential equations of newly constructed virtual rotor angle and internal electromotive force(EMF)in the SGM model.Moreover,the power flow of a DFIGWT is expressed by nonlinear functions of its virtual rotor angle and internal EMF.The SGM model bridges the gap between the irregular and complex modelling of DFIGWTs and the well-developed energy function construction techniques for SG models.Based on the SGM model,a numerical energy function is constructed for power systems with DFIGWT generation.Both theoretical analysis and numerical studies were undertaken to validate that the proposed energy function satisfies the necessary conditions for an energy function of a power system.展开更多
An advanced nonlinear robust control scheme is proposed for multi-machine power systems equipped with thyristor-controlled series compensation (TCSC). First, a decentralized nonlinear robust control approach based on ...An advanced nonlinear robust control scheme is proposed for multi-machine power systems equipped with thyristor-controlled series compensation (TCSC). First, a decentralized nonlinear robust control approach based on the feedback linearization and H∞ theory is introduced to eliminate the nonlinearities and interconnections of the studied system, and to attenuate the exogenous disturbances that enter die system. Then, a system model is built up, which has considered all the generators’ and TCSC’s dynamics, and the effects of uncertainties such as disturbances. Next, a decentralized nonlinear robust coordinated control law is developed based on this model. Simulation results on a six-machine power system show that the transient stability of the power system is obviously improved and die power transfer capacity of long distance transmission lines is enhanced regardless of fault locations and system operation points. In addition, the control law has engineering practicality since all the variables in the expression of he control strategy can be measured locally.展开更多
This paper proposes a switching structure excitation controller(SSEC)to enhance the transient stability of multimachine power systems.The SSEC switches between a bangbang funnel excitation controller(BFEC)and a conven...This paper proposes a switching structure excitation controller(SSEC)to enhance the transient stability of multimachine power systems.The SSEC switches between a bangbang funnel excitation controller(BFEC)and a conventional excitation controller(CEC),based on an appropriately designed state-dependent switching strategy.Only the tracking error of rotor angle is required to realize the BFEC in a bang-bang manner with two control values.If the feasibility assumptions of the BFEC are satisfied,the tracking error of rotor angle can be regulated within the predefined error funnels.The power system having the SSEC installed can achieve faster convergence performance compared to that having the CEC implemented only.Simulation studies are carried out in the New England 10-generator 39-bus power system.The control performance of the SSEC is evaluated in the cases that three-phase-to-ground fault and transmission line outage occur in the power system,respectively.展开更多
Using an energy-based Hamiltonian function method,this paper investigates the robust excitation control of multi-machine multi-load power systems described by a set of uncertain differential algebraic equations.First,...Using an energy-based Hamiltonian function method,this paper investigates the robust excitation control of multi-machine multi-load power systems described by a set of uncertain differential algebraic equations.First,we complete the dissipative Hamiltonian realization of the power system and adjust its operating point by the means of pre-feedback control.Then,based on the obtained Hamiltonian realization,we discuss the robust excitation control of the power system and put forward an H1 excitation control strategy.Simulation results demonstrate the effectiveness of the control scheme.展开更多
基金funded by State Key Program of National Natural Science of China(No.51437006)Guangdong Innovative Research Team Program(No.201001N0104744201),China.
文摘This paper proposes a coordinated switching power system stabilizer(SPSS)to enhance the stability of multimachine power systems.The SPSS switches between a bang-bang power system stabilizer(BPSS)and a conventional power system stabilizer(CPSS)based on a state-dependent switching strategy.The BPSS is designed as a bang-bang constant funnel controller(BCFC).It is able to provide fast damping of rotor speed oscillations in a bang-bang manner.The closed-loop stability of the power system controlled by the SPSSs and the CPSSs is analyzed.To verify the control performance of the SPSS,simulation studies are carried out in a 4-generator 11-bus power system and the IEEE 16-generator 68-bus power system.The damping ability of the SPSS is evaluated in aspects of small-signal oscillation damping and transient stability enhancement,respectively.Meanwhile,the coordination between different SPSSs and the coordination between the SPSS and the CPSS are investigated therein.
文摘This paper presented a novel wide-area nonlinear excitation control strategy for multi-machine power systems. A simple and effective model transformation method was proposed for the system's mathematical model in the COI (center of inertia) coordinate system. The system was transformed to an uncertain linear one where deviation of generator terminal voltage became one of the new state variables. Then a wide-area nonlinear robust voltage controller was designed utilizing a LMI (linear matrix inequality) based robust control theory. The proposed controller does not rely on any preselected system operating point, adapts to variations of network parameters and system operation conditions, and assures regulation accuracy of generator terminal voltages. Neither rotor angle nor any variable's differentiation needs to be measured for the proposed controller, and only terminal voltages, rotor speeds, active and reactive power outputs of generators are required. In addition, the proposed controller not only takes into account time delays of remote signals, but also eliminates the effect of wide-area information's incompleteness when not all generators are equipped with PMU (phase measurement unit). Detailed tests were conducted by PSCAD/EMTDC for a three-machine and four-machine power systems respectively, and simulation results illustrate high performance of the proposed controller.
基金This work was supported in part by the National Natural Science Foundation of China under Grant No.51807067the State Key Program of National Natural Science Foundation of China under Grant No.U1866210the Young Elite Scientists Sponsorship Program by CSEE under Grant No.CSEE-YESS-2018.
文摘In this paper we construct an energy function for multi-machine power systems with doubly-fed induction generator-based wind turbine(DFIGWT)according to a synchronous-generator-mimicking(SGM)model of the DFIGWT.An SGM model is proposed to approximate the dynamics of a DFIGWT.Similar to the modelling of a synchronous generator(SG),the internal dynamics of a DFIGWT are also described with differential equations of newly constructed virtual rotor angle and internal electromotive force(EMF)in the SGM model.Moreover,the power flow of a DFIGWT is expressed by nonlinear functions of its virtual rotor angle and internal EMF.The SGM model bridges the gap between the irregular and complex modelling of DFIGWTs and the well-developed energy function construction techniques for SG models.Based on the SGM model,a numerical energy function is constructed for power systems with DFIGWT generation.Both theoretical analysis and numerical studies were undertaken to validate that the proposed energy function satisfies the necessary conditions for an energy function of a power system.
基金This work was supported by Chinese National Natural Science Foundation(No.50377018)Chinese National Key Basic Research Fund(No.G1998020309)by New Energy and Industrial Technology Development Organization of Japan.
文摘An advanced nonlinear robust control scheme is proposed for multi-machine power systems equipped with thyristor-controlled series compensation (TCSC). First, a decentralized nonlinear robust control approach based on the feedback linearization and H∞ theory is introduced to eliminate the nonlinearities and interconnections of the studied system, and to attenuate the exogenous disturbances that enter die system. Then, a system model is built up, which has considered all the generators’ and TCSC’s dynamics, and the effects of uncertainties such as disturbances. Next, a decentralized nonlinear robust coordinated control law is developed based on this model. Simulation results on a six-machine power system show that the transient stability of the power system is obviously improved and die power transfer capacity of long distance transmission lines is enhanced regardless of fault locations and system operation points. In addition, the control law has engineering practicality since all the variables in the expression of he control strategy can be measured locally.
基金funded by State Key Program of National Natural Science of China(NO.51437006)Guangdong Innovative Research Team Program(NO.201001N0104744201),China。
文摘This paper proposes a switching structure excitation controller(SSEC)to enhance the transient stability of multimachine power systems.The SSEC switches between a bangbang funnel excitation controller(BFEC)and a conventional excitation controller(CEC),based on an appropriately designed state-dependent switching strategy.Only the tracking error of rotor angle is required to realize the BFEC in a bang-bang manner with two control values.If the feasibility assumptions of the BFEC are satisfied,the tracking error of rotor angle can be regulated within the predefined error funnels.The power system having the SSEC installed can achieve faster convergence performance compared to that having the CEC implemented only.Simulation studies are carried out in the New England 10-generator 39-bus power system.The control performance of the SSEC is evaluated in the cases that three-phase-to-ground fault and transmission line outage occur in the power system,respectively.
基金supported by the National Natural Science Foundation of China(Grant No.60974005)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20094101120008)the Nature Science Foundation of Henan Province(No.092300410201).
文摘Using an energy-based Hamiltonian function method,this paper investigates the robust excitation control of multi-machine multi-load power systems described by a set of uncertain differential algebraic equations.First,we complete the dissipative Hamiltonian realization of the power system and adjust its operating point by the means of pre-feedback control.Then,based on the obtained Hamiltonian realization,we discuss the robust excitation control of the power system and put forward an H1 excitation control strategy.Simulation results demonstrate the effectiveness of the control scheme.
