Research on Transient Overvoltage Control Strategy of UHVDC with Photovoltaic Power Plant

In the process of commutation failure and restart of UHVDC system with hierarchical, the reactive power consumption of converter is reduced. The reactive power of system is seriously surplus before AC filter is cut off, and different degrees of overvoltage appear on AC bus of UHVDC and photovoltaic power station, which may cause the disconnection of photovoltaic and other new energy equipment. This paper analyzes the mechanism of over-voltage when the power of UHVDC system is blocked. Based on this mechanism, a coordinated control strategy of transient overvoltage with reactive power surplus of UHVDC system and photovoltaic power station is proposed. The simulation results show that the proposed strategy can reduce the transient overvoltage during commutation failure of UHVDC system with hierarchical.