Single Pole-to-Ground Fault Location System for MMC-HVDC Transmission Lines Based on Active Pulse and CEEMDAN

To solve the problem of the location of the fault point of single-pole-to-ground faults in the transmission lines of MMC-HVDC systems, this paper designs a fault location system based on support vector machine (SVM). The waveform of the traveling wave after the fault occurs is collected as a feature, and the regression mechanism of the SVM is utilized to achieve fault location. Because it is very difficult to locate high-resistance ground faults, this paper first analyzes the waveform characteristics of high-resistance ground faults. Next, three steps are proposed to reduce the influence of grounding resistance on fault location. These steps include using the active pulse waveform as a new feature, classifying the samples according to ground resistance values before training regression models, and a method for adaptively extracting fault distance features is proposed. Finally, a complete location system design is proposed, and its workflow is illustrated. After the simulation test, the proposed location system only needs to obtain a single-ended fault voltage waveform at a fault recording frequency of 20 kHz to achieve an accurate location of single-pole-to-ground faults for different values of grounding resistance.