When the single pole fault occurs in the DC side overhead line of system
the voltage proportion of each frequency band of the single pole line presents different situations due to the different fault pole lines. Therefore
a single pole grounding fault location method of MMC-HVDC system based on fuzzy ratio analysis is proposed in this paper. In this method
the voltage of each frequency band during fault is separated through S-transform. Depending on the different proportion of voltage of each frequency band
the fault pole of the system can be quickly located only by one side of the device
and the weight of the proportion of voltage of each frequency band in the overall ranging can be found by neural network training
so as to finally realize the accurate location of fault location. Finally
PSCAD / EMTDC electromagnetic transient simulation software is used to build the two terminal bipolar flexible DC transmission model. The simulation results verify the accuracy of the proposed identification method and ranging algorithm.