The parameters of power system slowly change with time due to environmental effects or may change rapidly due to faults. It is preferable that the control technique in this system possesses robustness for various faul...The parameters of power system slowly change with time due to environmental effects or may change rapidly due to faults. It is preferable that the control technique in this system possesses robustness for various fault conditions and disturbances. The used flexible alternating current transmission system （FACTS） in this paper is an advanced super-conducting magnetic energy storage （ASMES）. Many control techniques that use ASMES to improve power system stability have been proposed. While fuzzy controller has proven its value in some applications, the researches applying fuzzy controller with ASMES have been actively reported. However, it is sometimes very difficult to specify the rule base for some plants, when the parameters change. To solve this problem, a fuzzy model reference learning controller （FMRLC） is proposed in this paper, which investigates multi-input multi-output FMRLC for time-variant nonlinear system. This control method provides the motivation for adaptive fuzzy control, where the focus is on the automatic online synthesis and tuning of fuzzy controller parameters （i.e., using online data to continually learn the fuzzy controller that will ensure that the performance objectives are met）. Simulation results show that the proposed robust controller is able to work with nonlinear and nonstationary power system （i.e., single machine-infinite bus （SMIB） system）, under various fault conditions and disturbances.展开更多
采用超导储能装置(Superconducting magnetic energy storage,SMES)的二阶模型,得到含SMES的单机无穷大电力系统模型。进而利用Lagrange化和间接Hamilton化理论,构造了该动态系统的Hamilton函数,并提出相应的SMES的稳定控制策略。最后,...采用超导储能装置(Superconducting magnetic energy storage,SMES)的二阶模型,得到含SMES的单机无穷大电力系统模型。进而利用Lagrange化和间接Hamilton化理论,构造了该动态系统的Hamilton函数,并提出相应的SMES的稳定控制策略。最后,利用Matlab进行仿真验证了笔者所提出控制律的正确性和有效性。结果表明,在大干扰的情况下,基于间接Hamilton化理论所设计的超导储能控制器能使系统快速地恢复到稳定运行状态,提高电力系统的暂态稳定性。展开更多
This paper studies how random phase （namely, noise-perturbed phase） effects the dynamical behaviours of a simple model of power system which operates in a stable regime far away from chaotic behaviour in the absence...This paper studies how random phase （namely, noise-perturbed phase） effects the dynamical behaviours of a simple model of power system which operates in a stable regime far away from chaotic behaviour in the absence of noise. It finds that when the phase perturbation is weak, chaos is absent in power systems. With the increase of disturbed intensity σ, power systems become unstable and fall into chaos as σ further increases. These phenomena imply that random phase can induce and enhance chaos in power systems. Furthermore, the possible mechanism behind the action of random phase is addressed.展开更多
This paper presents the design of a non-linear controller to prevent an electric power system losing synchronism after a large sudden fault and to achieve good post fault voltage level. By Direct Feedback Linearizatio...This paper presents the design of a non-linear controller to prevent an electric power system losing synchronism after a large sudden fault and to achieve good post fault voltage level. By Direct Feedback Linearization (DFL) technique robust non-linear excitation controller is designed which will achieve stability enhancement and voltage regulation of power system. By utilizing this technique, there is a possibility of selecting various control loops for a particular application problem. This method plays an important role in control system and power system engineering problem where all relevant variables cannot be directly measured. Simulated results carried out on a single machine infinite bus power system model which shows the enhancement of transient stability regardless of the fault and changes in network parameters.展开更多
In this paper, the Authors present the designing of power system stabilizer (PSS) and static var compensator (SVC) based on chaos, particle swarm optimization (PSO) and shuffled frog leaping (SFL) Algorithms has been ...In this paper, the Authors present the designing of power system stabilizer (PSS) and static var compensator (SVC) based on chaos, particle swarm optimization (PSO) and shuffled frog leaping (SFL) Algorithms has been presented to improve the power system stability. Single machine infinite bus (SMIB) system with SVC located at the terminal of generator has been considered to evaluate the proposed SVC and PSS controllers. The coefficients of PSS and SVC controller have been optimized by Chaos, PSO and SFL algorithms. Fi-nally the system with proposed controllers is simulated for the special disturbance in input power of genera-tor, and then the dynamic responses of generator have been presented. The simulation results show that the system composed with recommended controller has outstanding operation in fast damping of oscillations of power system and describes an application of Chaos, PSO and SFL algorithms to the problem of designing a Lead-Lag controller used in PSS and SVC in power system.展开更多
The use of power systems as close to their operating limits can cause instability if a disturbance is occurred. The damping of the system’s oscillations can be obtained by conventional means such as voltage and speed...The use of power systems as close to their operating limits can cause instability if a disturbance is occurred. The damping of the system’s oscillations can be obtained by conventional means such as voltage and speed regulation but also by Flexible AC Transmission System devices (FACTS). These devices are increasingly used in power systems. This paper presents a systematic procedure for modelling and simulation of a single-machine infinite-bus power system installed with a Static VAR Compensator (SVC). So the impact of the SVC on power system stability can be reasonably evaluated. Genetic algorithm (GA) optimization technique is applied to design robust power system stabilizer and SVC-controllers for single-machine infinite-bus (SMIB) and is employed to search for optimal controller parameters.展开更多
Selection of better optimized unified power flow controller （UPFC） control inputs along with simultaneous coordinated design of power system stabilizer （PSS） is a challenge in the present scenario of power systems...Selection of better optimized unified power flow controller （UPFC） control inputs along with simultaneous coordinated design of power system stabilizer （PSS） is a challenge in the present scenario of power systems. Hence, in this paper, four sets of experiments performed are presented. First set of experiments are without disturbance scenario where switching is done using linear quadratic regulators （LQR＇s）. Second set is for power systems with disturbances using linear quadratic gaussian （LQG）. Switching control algorithms presented here are tested on the single machine infinite bus （SMIB） linearised Phillips Heffron model of power system using MATLAB/SIMULINK~ platform.展开更多
An SMIB model in the power systems, especially that concering the effects of hard limits on bifurcations, chaos and stability is studied. Parameter conditions for bifurcations and chaos in the absence of hard limits a...An SMIB model in the power systems, especially that concering the effects of hard limits on bifurcations, chaos and stability is studied. Parameter conditions for bifurcations and chaos in the absence of hard limits are compared with those in the presence of hard limits. It has been proved that hard limits can affect system stability. We find that (1) hard limits can change unstable equilibrium into stable one; (2) hard limits can change stability of limit cycles induced by Hopf bifurcation; (3) persistence of hard limits can stabilize divergent trajectory to a stable equilibrium or limit cycle; (4) Hopf bifurcation occurs before SN bifurcation, so the system collapse can be controlled before Hopf bifurcation occurs. We also find that suitable limiting values of hard limits can enlarge the feasibility region. These results are based on theoretical analysis and numerical simulations, such as condition for SNB and Hopf bifurcation, bifurcation diagram, trajectories, Lyapunov exponent, Floquet multipliers, dimension of attractor and so on.展开更多
文摘The parameters of power system slowly change with time due to environmental effects or may change rapidly due to faults. It is preferable that the control technique in this system possesses robustness for various fault conditions and disturbances. The used flexible alternating current transmission system （FACTS） in this paper is an advanced super-conducting magnetic energy storage （ASMES）. Many control techniques that use ASMES to improve power system stability have been proposed. While fuzzy controller has proven its value in some applications, the researches applying fuzzy controller with ASMES have been actively reported. However, it is sometimes very difficult to specify the rule base for some plants, when the parameters change. To solve this problem, a fuzzy model reference learning controller （FMRLC） is proposed in this paper, which investigates multi-input multi-output FMRLC for time-variant nonlinear system. This control method provides the motivation for adaptive fuzzy control, where the focus is on the automatic online synthesis and tuning of fuzzy controller parameters （i.e., using online data to continually learn the fuzzy controller that will ensure that the performance objectives are met）. Simulation results show that the proposed robust controller is able to work with nonlinear and nonstationary power system （i.e., single machine-infinite bus （SMIB） system）, under various fault conditions and disturbances.
文摘采用超导储能装置(Superconducting magnetic energy storage,SMES)的二阶模型,得到含SMES的单机无穷大电力系统模型。进而利用Lagrange化和间接Hamilton化理论,构造了该动态系统的Hamilton函数,并提出相应的SMES的稳定控制策略。最后,利用Matlab进行仿真验证了笔者所提出控制律的正确性和有效性。结果表明,在大干扰的情况下,基于间接Hamilton化理论所设计的超导储能控制器能使系统快速地恢复到稳定运行状态,提高电力系统的暂态稳定性。
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10862001,10947011 and 70571017)
文摘This paper studies how random phase （namely, noise-perturbed phase） effects the dynamical behaviours of a simple model of power system which operates in a stable regime far away from chaotic behaviour in the absence of noise. It finds that when the phase perturbation is weak, chaos is absent in power systems. With the increase of disturbed intensity σ, power systems become unstable and fall into chaos as σ further increases. These phenomena imply that random phase can induce and enhance chaos in power systems. Furthermore, the possible mechanism behind the action of random phase is addressed.
文摘This paper presents the design of a non-linear controller to prevent an electric power system losing synchronism after a large sudden fault and to achieve good post fault voltage level. By Direct Feedback Linearization (DFL) technique robust non-linear excitation controller is designed which will achieve stability enhancement and voltage regulation of power system. By utilizing this technique, there is a possibility of selecting various control loops for a particular application problem. This method plays an important role in control system and power system engineering problem where all relevant variables cannot be directly measured. Simulated results carried out on a single machine infinite bus power system model which shows the enhancement of transient stability regardless of the fault and changes in network parameters.
文摘In this paper, the Authors present the designing of power system stabilizer (PSS) and static var compensator (SVC) based on chaos, particle swarm optimization (PSO) and shuffled frog leaping (SFL) Algorithms has been presented to improve the power system stability. Single machine infinite bus (SMIB) system with SVC located at the terminal of generator has been considered to evaluate the proposed SVC and PSS controllers. The coefficients of PSS and SVC controller have been optimized by Chaos, PSO and SFL algorithms. Fi-nally the system with proposed controllers is simulated for the special disturbance in input power of genera-tor, and then the dynamic responses of generator have been presented. The simulation results show that the system composed with recommended controller has outstanding operation in fast damping of oscillations of power system and describes an application of Chaos, PSO and SFL algorithms to the problem of designing a Lead-Lag controller used in PSS and SVC in power system.
文摘The use of power systems as close to their operating limits can cause instability if a disturbance is occurred. The damping of the system’s oscillations can be obtained by conventional means such as voltage and speed regulation but also by Flexible AC Transmission System devices (FACTS). These devices are increasingly used in power systems. This paper presents a systematic procedure for modelling and simulation of a single-machine infinite-bus power system installed with a Static VAR Compensator (SVC). So the impact of the SVC on power system stability can be reasonably evaluated. Genetic algorithm (GA) optimization technique is applied to design robust power system stabilizer and SVC-controllers for single-machine infinite-bus (SMIB) and is employed to search for optimal controller parameters.
文摘Selection of better optimized unified power flow controller （UPFC） control inputs along with simultaneous coordinated design of power system stabilizer （PSS） is a challenge in the present scenario of power systems. Hence, in this paper, four sets of experiments performed are presented. First set of experiments are without disturbance scenario where switching is done using linear quadratic regulators （LQR＇s）. Second set is for power systems with disturbances using linear quadratic gaussian （LQG）. Switching control algorithms presented here are tested on the single machine infinite bus （SMIB） linearised Phillips Heffron model of power system using MATLAB/SIMULINK~ platform.
基金Supported by The National Key Basic Research Fundation (No.G1998020307)
文摘An SMIB model in the power systems, especially that concering the effects of hard limits on bifurcations, chaos and stability is studied. Parameter conditions for bifurcations and chaos in the absence of hard limits are compared with those in the presence of hard limits. It has been proved that hard limits can affect system stability. We find that (1) hard limits can change unstable equilibrium into stable one; (2) hard limits can change stability of limit cycles induced by Hopf bifurcation; (3) persistence of hard limits can stabilize divergent trajectory to a stable equilibrium or limit cycle; (4) Hopf bifurcation occurs before SN bifurcation, so the system collapse can be controlled before Hopf bifurcation occurs. We also find that suitable limiting values of hard limits can enlarge the feasibility region. These results are based on theoretical analysis and numerical simulations, such as condition for SNB and Hopf bifurcation, bifurcation diagram, trajectories, Lyapunov exponent, Floquet multipliers, dimension of attractor and so on.
