针对并网风电场故障期间无功不足的问题,采用新型动态无功补偿装置是必然趋势。根据异步风力发电机模型、统一潮流控制器(UPFC)的工作原理与控制策略,建立了含UPFC装置的风电场并网系统仿真模型。仿真对比分析了异步风电场安装SVC和安装UPFC装置时发生短路故障后的故障穿越能力;分析了暂态过程风电机组超速的原因,并研究了异步风力电机组成的风电场故障前后电压、功率和转速变化情况。仿真结果表明,与SVC相比,新型无功补偿装置UPFC作为风电场无功电源,其响应速度更快,风电场暂态稳定性得到更好地改善。
It is an inevitable trend to compensate the reactive power deficits in wind farms during system failures with dynamic reactive power compensation devices.In this paper,a system simulation model including unified power flow controllers(UPFCs) used for wind farm access study is established based on asynchronous wind turbine generator model and the principle and control strategy of UPFC The comparison of fault ride-through capability is executed between the wind farms installed with SVC and UPFC.The reasons for wind turbine over-speed in transient process are analyzed.Moreover,the voltage,power and speed of the asynchronous wind turbine generator before and after faults are also studied.The simulation shows that,compared with SVC,the response of UPFC is faster,therefore,by using UPFC as the reactive power source,the transient stability of wind farms can be enhanced further.