The Fault Current Limitation Method for Cascaded Hybrid HVDC

Aiming at the MMC DC overcurrent problems caused by LCC commutation failure on the receiving end, a fault ride-through method based on fault current limiter is proposed, including the topology structure, working principle, control method and parameter design method. With the help of the fault current limiter, the sub-module capacitor discharge circuit of the MMC DC-side monopole grounding fault can be blocked to protect the MMC valve set. When the receiving end LCC commutation failure leads to MMC DC overcurrent, the fault current limiter limits the MMC DC overcurrent through the input of current limiter resistor to prevent the MMC from blocking and alleviates the MMC DC overvoltage problem to a certain extent. The simulation results verify the effectiveness of the proposed fault ride-through method.