Abstract：To address the issue of transient overvoltage at the sending end of the wind farm caused by faults in

conventional high-voltage direct current systems system，the impact mechanism of DC faults on transient voltage

changes at the sending end was analyzed. It was discovered that the reactive power surplus of the AC system after

the fault was the root cause of the sudden voltage rise. To address this，a reactive power coordination control

strategy based on distributed synchronous condensers and doubly fed induction generators（DFIG）was proposed. A distributed synchronous condenser was installed at the grid-connected bus of the wind farm to stabilize the gridconnected voltage and improve the low-voltage or high-voltage ride-through capability of the wind farm using its unique reactive power regulation characteristics. During various severe fault scenarios in the DC system，the DFIG

participated in reactive power regulation by changing the reactive power reference value，and improved system

voltage during the fault period with the distributed synchronous condenser. The DFIG wind farm was controlled to

exit reactive power regulation during steady-state after the fault，to ensure economic operation after fault recovery.

Simulation results using PSCAD software demonstrate that the proposed reactive power coordination control

strategy effectively suppress transient voltage variations of the wind farm after faults，improving the reliability and

economy of the wind farm，particularly during commutation failure and direct current blocking in the system.

      Key words：high-voltage direct current（HVDC）；wind farm；distributed synchronous condenser；reactive

power compensation；coordination control