考虑源网协调的风电场动态无功补偿装置控制策略

Dynamic reactive power compensator control considering source-grid coordination for wind farm

通过分析动态无功补偿装置感性支路恒无功控制对地区电网无功电压灵敏度的作用机理,指出该控制容易造成扰动后系统电压的大幅波动,从而从原理上指明风电场动态无功补偿装置采用恒电压辅助控制的必要性,并从源网协调的角度提出一种动态无功补偿装置主/辅协调控制策略。该协调控制策略可实现系统运行工况变化时感性支路恒无功控制与低压侧恒电压控制间的灵活切换,从而避免了扰动后系统电压的大幅波动,进而降低了风机高电压脱网事故风险。借助PSS/E搭建风机脱网事故地区风电汇集系统模型模拟风机高电压脱网过程,验证了所提控制策略避免扰动后风机高电压脱网的效果。

The affect of constant reactive power control tot the inductive branch oI dynamic reactive power compensator on the reactive voltage sensitivity of regional grid is analyzed,which shows that it may easily lead to the substantial voltage fluctuation after disturbance,and the necessity for applying the constant voltage auxiliary control in the dynamic reactive power compensator of wind farm is pointed out. A strategy of main/auxiliary coordinated control is proposed from the source-grid coordination for the dynamic reactive power compensator,which,when the operating condition of system changes,realizes the flexible switchover between the constant reactive power control in inductive branch and the constant voltage control at low- voltage side to avoid the substantial voltage fluctuation after disturbance and reduce the risk of wind turbine high-voltage trip-off accident. A model of grid-connected wind power system is built with PSS/E to simulate the process of wind turbine high-voltage trip-off accident,which verifies the effect of the proposed control strategy in avoiding the wind turbine high-voltage trip-off accident after disturbance.