电压源换相高压直流输电对改善风电场电压稳定性的作用

Effect of VSC-HVDC Applied on Improving Wind Farm Voltage Stability

并网风电场无功功率的波动会引起系统电压波动。在风电场混合并网系统中,通过电压源换相高压直流输电可以控制系统中的无功功率、抑制并网公共点的电压波动。文章研究了换流站无功功率控制器和定电压控制器对改善并网风电场电压稳定性的作用。基于电磁暂态软件PSCAD/EMTDC建立了并网风电场模型、电压源换相高压直流输电模型及其控制系统模型。仿真结果验证了上述控制器的正确性和可行性,表明采用定电压控制器的并网系统能更好地抑制电压波动,采用无功功率控制器的并网系统具有更好的风电场并网性能。

The reactive power variation of wind farm interconnected with power grid leads to voltage fluctuation of power grid. In interconnected hybrid wind farm system, the voltage fluctuation can be alleviated and the reactive power can be controlled by voltage source converter. Here the reactive power controller and stable voltage controller of VSC-HVDC are designed. Based on electromagnetic transient software PSCAD/EMTDC, the interconnected wind farm model and VSC-HVDC model as well as the model of their controllers are set up. Simulation results show that in interconnected wind farm system in which the stable voltage controller is adopted, the voltage fluctuation can be alleviated better, and yet the interconnected wind farm system in which the reactive power controller is adopted possesses better interconnection performance and the correctness and feasibility of the controllers are verified.