基于VSC-HVDC风电并网系统风电场侧故障下系统低电压穿越能力研究

Low Voltage Ride-through Technology for Wind Farm Side Fault of VSC-HVDC Grid-Connected Wind Power System

针对经柔性直流输电(VSC-HVDC)并网的风电场,风电场侧故障易造成风机脱网的问题,提出了一种新型无功控制策略。该策略能充分利用故障两侧的无功源,即双馈风力发电机(DFIG)与VSC-HVDC风电场侧变流器(WFSVSC)来提供无功支持,实现低电压穿越。采用DIgSILENT软件进行仿真,仿真结果表明该控制策略能有效减小故障恢复期间的电压波动,缩短故障恢复时间,具有更好的低电压穿越能力。

For VSC-HVDC grid-connected wind power system,wind farm side fault often causes wind turbine grid-off.This paper proposes a new reactive power control strategy,which can make full use of both sides of the reactive power source,namely,the doubly-fed wind power generator（DFIG）and the VSC-HVDC wind farm side converter（WFSVSC）,to provide reactive power support to achieve low voltage ride-through.And the DIgSILENT software is applied for simulation,and the simulation results show that the proposed control strategy can effectively reduce the voltage fluctuation during the fault recovery,shorten recovery time,and exhibit better low voltage ride-through ability.