电网故障时风电场基于STATCOM的无功协调控制策略

摘要

为充分发挥双馈感应风力发电机组(DFIG)在电网故障时的无功功率调节能力,采用静止无功补偿器(STATCOM)进行补偿,建立风电场无功实时协调控制系统(CRRCS).CRRCS可通过监测电网故障状态、撬棍保护((crowbar)动作状态、风电机组运行状态及公共连接点(PCC)电压水平等信息,实时协调处理风电场各机组、STATCOM及PCC的无功电压控制策略.同时进一步采用故障时刻的极限功率控制模式,以降低crowbar动作概率,保障机组的无功功率调节能力.仿真分析证明,该方法可有效保证电网故障时DFIG的无功调节能力,并控制补偿单元及风电场,为电网提供无功和电压支撑,协助实现风电场的故障穿越运行.%To fully employ the reacctive power generation capability of DFIGs under grid faults,a coordinated real-time reactive power control system (CRRCS)for wind farms with a STATCOM was built.By monitoring slystem fault conditions,crowbar actions ,wind turbine operation status and voltage levels of the point of the common coupling (PCC),the CRRCS can coordinate the control of reactive power for the wind turbines,STSTCOM and PCC.In addition,by adoptiong of limit power control mode,the CRRCS can reduce the possibility of crowbar action and ensure the reactive power supply from DFIGs.Simulation results indicate that under grid faults the proposed system can secure the reactive power generation capability of DFIGs,provide reactive power and voltage supports for the system and realize fault ride-through of wind farms.