风电场柔性直流输电的故障穿越方法对风电机组的影响

柔性直流输电(VSC-HVDC)系统是大型风电场并网的较好选择,当发生交流系统故障时,故障穿越控制器可维持该系统的稳定性。然而,控制器会对风电机组造成一定影响。针对大型风电场VSC-HVDC系统接入的故障穿越问题,文中首先在PSCAD/EMTDC中建立了含有普通异步/双馈风电场详细模型的两端VSC-HVDC系统仿真模型,并验证了升频法和降压法两种典型的故障穿越方法。然后进一步研究了不同类型风电机组在不同的故障穿越方法下的特性和差异,从而得出风电场VSC-HVDC系统的故障穿越方法对风电机组的影响规律。研究得出的结论可以为不同类型的风电机组接入VSC-HVDC系统时故障穿越方法的选择提供一定的参考依据。

Impact of Fault Ride-through Methods on Wind Power Generators in a VSC-HVDC System

Voltage source converter based high voltage direct current (VSC-HVDC) system is a relatively good choice for the grid integration of large-scale wind farms. When faults occur in the AC grid, the fault ride-through (FRT) controller of wind power generators can maintain the stability of the system. However, the controller will have impact on the wind power generators performance. To study on the FRT problem for wind power generators in a VSC-HVDC system, this paper develops a simulation model of the two terminal VSC-HVDC system including detailed models of wind farms with conventional asynchronous generators and doubly fed induction generators (DFIGs) using PSCAD/EMTDC. Two typical FRT methods, i.e., frequency increase method and voltage reduction method are verified. Furthermore, the characteristics of different wind power generators with different FRT methods are studied. The typical impact of FRT methods on the wind power generators in a VSC HVDC system is obtained. The conclusions can provide a reliable reference for choosing appropriate FRT methods for different wind power generators integrated into a VSC HVDC system.