Research of Synchronous condenser and UHVDC Reactive voltage coordinate control strategy for ± 800kV Xiangtan Converter Station

In order to improve the dynamic reactive power support capability and suppress the DC commutation failure, it is a new trend to configure synchronous condenser at the DC converter station for emergency control. However, at present, the synchronous condenser is only used for transient support, the reactive power output is basically zero during steady-state operation, ignoring its steady-state reactive power adjustment capability, and failing to fully utilize the reactive support of the new generation of synchronous condenser. Based on the current UHVDC reactive voltage and synchronous condenser control strategy, this paper proposes a UHV DC reactive voltage coordinated control strategy based on voltage-reactive matching to achieve voltage fluctuations suppression during filter bank switching and Reactive power compensation during fixed capacitor switching, effectively reducing the risk of commutation failure caused by voltage fluctuations to UHVDC operation, and improving the economics of AC filter bank operation.