计及动态无功控制影响的风电汇集地区高电压脱网原因分析

Analysis on High-voltage Trip-off Causation of Dense Wind Power Areas Considering Impact of Dynamic Reactive Power Control

回顾电网实际发生的某次风电机组高电压脱网事故典型特征,总结提出:研究导致事故深层原因应充分考虑风电场汇集地区动态无功补偿控制的影响。基于简单系统推导出计及风电场感性支路恒无功控制影响的无功功率—电压灵敏度表达式,从原理上阐明目前动态无功补偿装置所广泛采用的感性支路恒无功控制方式将导致大规模风电汇集地区电网无功功率—电压灵敏度增大,其增大的幅度取决于感性支路的初值,并最终指出风电场感性支路恒无功控制方式导致的无功功率—电压灵敏度增大是导致"5·14"风电大规模脱网的主要原因之一。最后,结合实际系统的典型案例进行了仿真验证。

The typical characteristics of a certain high-voltage trip-off accident of wind turbines that does happen in a power system are reviewed.It is concluded that in learning about the root cause of the accident,we need to give careful consideration of the impact of dynamic reactive compensation control.Based on a simple equivalent system,the reactive power-voltage sensitivity expression considering the influence of constant reactive power control of inductive branch in dense wind power areas is derived.It is proved in principle that constant reactive power control on the inductive branch adopted by a static reactive compensator will cause an increase in reactive power-voltage sensitivity.And the growth rate depends on the initial value of the inductive branch.Further,it is pointed out that the increase in reactive power-voltage sensitivity due to constant reactive power control on the inductive branch is one of the main causes that leads to the“5 ·14＂ high-voltage trip-off accident.Finally,the typical case of an actual system is verified by simulation.