本文建立了PSCAD/EMTDC下基于电压源型换流器的多端直流(VSC-MTDC)输电系统模型。每个换流站采用基于IGBT三相桥型拓扑结构,设计了定有功功率控制器、定无功功率控制器和定直流电压控制器。分析了VSC中的电压偏差控制和直流电压–有功...本文建立了PSCAD/EMTDC下基于电压源型换流器的多端直流(VSC-MTDC)输电系统模型。每个换流站采用基于IGBT三相桥型拓扑结构,设计了定有功功率控制器、定无功功率控制器和定直流电压控制器。分析了VSC中的电压偏差控制和直流电压–有功功率下降控制的工作原理,指出了电压偏差控制存在的问题,提出了一种综合直流电压控制策略。仿真结果表明综合电压控制方式响应迅速,功率潮流自动调整且超调量小,稳定性增强。>A multi-terminal HVDC system (MTDC) based on voltage source converter (VSC) is built in PSCAD/ EMTDC in this paper. Each converter station has three-phase bridge topology with IGBT. Its control system is designed to realize the real power control, reactive power control and DC voltage control. The principles of voltage deviation control and voltage-power drop control in VSC are analyzed. Considering the problems of voltage deviation control, an improved DC voltage control strategy is put forward. Simulation results show that integrated voltage control has quick response, power flow self-regulation, small overshoot and enhanced stability.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
文摘本文建立了PSCAD/EMTDC下基于电压源型换流器的多端直流(VSC-MTDC)输电系统模型。每个换流站采用基于IGBT三相桥型拓扑结构,设计了定有功功率控制器、定无功功率控制器和定直流电压控制器。分析了VSC中的电压偏差控制和直流电压–有功功率下降控制的工作原理,指出了电压偏差控制存在的问题,提出了一种综合直流电压控制策略。仿真结果表明综合电压控制方式响应迅速,功率潮流自动调整且超调量小,稳定性增强。>A multi-terminal HVDC system (MTDC) based on voltage source converter (VSC) is built in PSCAD/ EMTDC in this paper. Each converter station has three-phase bridge topology with IGBT. Its control system is designed to realize the real power control, reactive power control and DC voltage control. The principles of voltage deviation control and voltage-power drop control in VSC are analyzed. Considering the problems of voltage deviation control, an improved DC voltage control strategy is put forward. Simulation results show that integrated voltage control has quick response, power flow self-regulation, small overshoot and enhanced stability.
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.
