Sequential Coordination Method of Multiple HVDC Commutation Failures Based on Voltage Stiffness

In a multi-infeed LCC-HVDC power system, simultaneous recovery of multiple LCC-HVDCs from commutation failures will absorb a large amount of reactive power at the same time, which is not conducive to the voltage stability of the receiving end grid. For this reason, staggered recovery of multiple LCC-HVDe commutation failures is an economical and effective means to improve the voltage stability of the receiving-end grid. First, the system model of the multi-infeed power system is introduced, and the voltage stability constraints are deduced based on the voltage stiffness. Then, the sequential coordination method of multiple HVDC systems is proposed. Finally, the modified IEEE 39-bus system is tested to verify the effectiveness of the proposed method.