Optimization of Grid-Forming Energy Storage Systems to Enhance Sending-end Power System Stability

The transient voltage rise in the vicinity of the sending-end converter station and the insufficient reactive power support at voltage weak points after a DC fault seriously affect the safe and stable operation of the power grid and also limit the transmission capacity of the DC line. Grid-forming energy storage system(GFM-ESS) has a rapid reactive power response capability and can provide reactive power or absorb reactive power for the system in a short time, accelerating the recovery speed of bus voltage and contributing to the stable operation of the power system. Therefore, using GFM-ESS to regulate voltage at transient voltage rise points and voltage valleys can effectively solve the problem of voltage stability. This paper analyzes the working mechanism and location basis of GFM-ESS and proposes a site and capacity configuration method for GFM-ESS based on the comprehensive voltage trajectory sensitivity index(TSI) of multiple stations. The impact of this method on the voltage stability of the power system and the DC transmission capacity is also studied. Finally, the effectiveness of the proposed method is verified through a practical power grid example.