基于快速开关提升风电场低电压穿越成功率的研究

装设自动重合闸的风机馈线发生永久性故障时,并网点电压会发生两次跌落造成风机低电压穿越失败,针对上述现象提出了一种采用快速开关提升风电机组低电压穿越成功率的方法。该方法以国标为基准分析快速开关应用于风机低电压穿越场景的机理,利用快速保护断路器本体与控制系统的配合,较大程度地缩短故障电流对系统的冲击时间。以某风电场接入电力系统为例,在PSCAD/EMTDC中分别对比了采用传统断路器和快速开关的10 kV馈线发生各种短路故障时并网点电压的跌落情况。仿真结果表明:基于快速开关提升风机低电压穿越成功率的方法能够显著地缩短故障电流对系统的冲击时间,较大程度地保障风机在并网点电压两次跌落的情况下保持并网运行。

Research on improving success rate of low voltage ride-through of wind farm based on fast switch

When a permanent fault occurs in the feeder line of a wind turbine equipped with automatic reclosing,the voltage at the connecting point will drop twice,resulting in the failure of low voltage ride-through of the wind turbine.In view of the above phenomenon,a method was proposed to improve the success rate of low voltage ride-through of wind turbine by using fast switch.Based on the national standard,the mechanism of the fast switch applied to the low voltage ride-through scenario of the wind turbine was analyzed by the method.By using the coordination of the fast protection circuit breaker and the control system,the impact time of the fault current on the system was greatly reduced.Taking a wind farm connected to the power system as an example,the voltage drop of 10 kV feeder with traditional circuit breaker and fast switch were compared in PSCAD / EMTDC.The simulation results show that the method of improving the success rate of low voltage ride-through of wind turbine based on fast switching can significantly shorten the impact time of fault current on the system,and ensure the wind turbine to keep grid connected operation under the condition of voltage drop twice at the grid connection point.