Energy Storage Active and Reactive Power Coordinated Control Considering DC Commutation Failue Voltage Recovery and Restraining AC Line Active Power Fluctuation

Commutation failure is one of the common faults of high-voltage DC system. With the rapid commissioning of UHVDC project, the risk of commutation failure is greater. Commutation failure causes the power interaction between DC system and AC system to fluctuate greatly. The time scale of AC bus voltage recovery during continuous commutation failure is about hundreds of milliseconds, and the time scale of AC line active power fluctuation after commutation failure recovery is about seconds to tens of seconds. In this paper, it is proposed that energy storage gives priority to dynamic reactive power to support voltage recovery of AC bus after commutation failure, and to suppress subsequent commutation failure of DC. When the DC commutation failure is recovered, the energy storage starts to output active power reversely to stabilize the fluctuation of AC line active power. Finally, through the actual power grid simulation example, the effectiveness of coordinated control of active and reactive energy storage, suppression of subsequent commutation failure for AC bus voltage recovery and optimization of AC/DC power grid operation characteristics to stabilize AC line active power fluctuation is verified.