Research on influencing factors and changes of DC current after commutation failure

Commutation failure is one of the most common faults in HVDC operation, and the DC current surge caused by it is not only one of the characteristics of commutation failure, but also an important basis for overcurrent protection of DC systems. This paper introduces the factors that affect the DC current change after commutation failure in the DC system, makes some modification to the simplified mathematical model of the DC system, and compares the theoretical calculation results with the simulation results. Finally, an extreme case is considered, so that the calculation result covers the most serious fault situation, which provides a reference for the protection of the DC system.