Influence Analysis of New Energy Proportion in the AC System on DC Fault Current of the MMC-HVDC System

Abstract

The paper study the influence of new energy of AC system on DC fault current characteristics in MMC-HVDC system. Analyze the equivalent method of MMC converter station when MMC-HVDC system occurs DC fault, compare the DC fault current value calculated by the two equivalent methods of the RLC series circuit and the RLC series circuit for a constant current source parallel at both sides of the capacitor with the PSCAD model simulation value, it is concluded that the fault current calculation method considering the influence of AC system is more accurate. Analyze the change of DC fault current of MMC-HVDC system under different proportions of new energy in the AC system, the results show that the proportion of new energy in the AC system has little influence on the DC fault current.