高压直流输电系统出现闭锁、换相失败等故障时,会引起送端换流站附近新能源电站的瞬时电压波动并易导致其脱网.首先,分析了构网型储能开环控制策略的运行原理、响应特性和关键参数影响.然后,分析了调相机的无功响应特性,并将构网型储能无功控制模型与调相机的励磁调节控制模型进行对比.最后,搭建了包含特高压直流、光伏、调相机、构网型储能的半实物仿真系统,进行了直流换相失败故障下的交流暂态过电压抑制效果对比试验.结果表明,容量相同的构网型储能和分布式调相机在无功瞬时响应速度、抑制交流暂态过电压能力方面可以实现相近的效果.
When faults such as blocking and commutation failure occur in a high-voltage direct current(HVDC)transmission system,they can cause transient voltage fluctuations near the sending-side converter station and lead to the disconnection with power grid.Firstly,the operating principles,response characteristics,and key parameter in-fluences of the grid-forming energy storage open-loop control strategy are analyzed.Then,the reactive response char-acteristics of the synchronous condenser are analyzed,and a comparison is made between the grid-forming energy storage reactive power control model and the excitation regulation control model.Finally,a semi-physical simulation system is established,including EHVDC,photovoltaics,synchronous condenser,and grid-forming energy storage,to conduct comparative experiments on the effect of suppressing AC transient overvoltage under DC commutation failure.The results indicate that grid-forming energy storage and distributed synchronous condenser with the same capacity can achieve similar effects in terms of reactive transient response speed and the ability to suppress AC tran-sient overvoltage.