During normal operation of DC lines

the smoothing reactor can reduce current ripple. When a DC line fails

the rapid operation of the current limiting reactor can suppress the rising speed of the fault current. Therefore

considering the collaboration between current limiting reactors and smoothing reactors can not only suppress the rising speed of fault current

but also reduce the cutting capacity of DC circuit breakers. However

due to investment costs and system dynamic characteristics

the inductance capacity of smoothing reactors and current limiting reactors needs to be maintained within a reasonable range. Therefore

it is very meaningful to optimize the capacity configuration of smoothing reactors and current limiting reactors in the HVDC transmission system

while ensuring the current limiting capacity and reducing investment. Firstly

a fault equivalent model for the AC/DC hybrid power grid is established and the characteristics of the fault current at both ends when a bipolar short circuit occurs in the DC line are analyzed. Secondly

a mathematical model for optimizing the configuration of smoothing reactors and current limiting reactors is established. Finally

the proposed current limiting strategy is validated through MATLAB simulation experiments.