Research on the Solution of Voltage Stability in Shenzhen during the Asynchronous Interconnection Construction of Guangdong

This paper analyzes the mechanism of voltage stability in Shenzhen after Guangdong back-to-back flexible DC project operated in order to keep the voltage stability in Shenzhen during the Asynchronous Interconnection construction of Guangdong and improve the stability of Shenzhen power grid under serious AC fault. After that, the paper puts forward the adaptive switching VDCOL strategy and applies it to Xindong and Xing'an HVDC projects. At last, the paper verifies its effectiveness through RTDS simulation. The main conclusions are as follows: (1) The voltage stability problem in Shenzhen may be caused by the insufficient dynamic reactive power support capacity of the power grid and the rapid increase of reactive power consumption demand of HVDC system after AC fault; (2) The adaptive switching VDCOL strategy can switch the optimization parameters in the case of serious AC fault on the inverter side, which has a great influence on the power recovery characteristics of Xindong HVDC stations, while its slow power recovery characteristics will not cause the frequency of Yunnan power grid to exceed the limit; (3) After Xindong and Xing 'an HVDC implement the adaptive switching VDCOL strategy, there is rare voltage stability problems in Shenzhen power grid due to serious AC faults, which fully proving the effectiveness of the proposed strategy.