Abstract：In DC power grid，when serious metallic short circuit fault occurs in the DC side line of voltage

source converter（VSC），the fault current has the characteristics of a fast rising speed and a large peak. The DC

circuit breaker is used to isolate the fault，which greatly increases the requirements for the quick action and

breaking capacity of the DC circuit breaker. Based on the VSC bipolar short circuit fault characteristics，a fault

current limiting scheme with residual current operated protective device（RCD）current peak suppression circuit in

series with the DC line was proposed. The current limiting circuit，which controlled the opening and closing of the

thyristor，not only interrupted the discharge loop of the DC side capacitor to the fault point，but also effectively

reduced the peak fault current and limited the fault steady state current to a given reference value.The PSCAD/

EMTDC simulation platform was used to test the VSC bipolar short circuit fault and the proposed current limiting

scheme，and the effectiveness of the proposed scheme was compared with that of the other two fault current

limiting schemes，which verified the superiority of the proposed scheme based on energy transfer circuit.

      Key words：voltage source converter（VSC）；fault current limiting；residual current operated protective device （RCD）current peak suppresses circuit