Research on the Mathematical Model of Cable Single-Phase Ground Fault Arc Simplified from MHD Simulation

Single-phase grounding faults rank as the most prevalent and challenging failures within distribution networks, with arc grounding faults making up the majority of these incidents, especially in three-core cable. In order to realize the rapid identification of grounding fault in cable distribution network, an arc model of cable grounding fault arc based on magnetohydrodynamics (MHD) simulation is established. By outputting and observing the physical change, the arc-burning phenomenon during the process of single-phase grounding fault is analyzed. Through the MHD simulation, the arc time constant and heat dissipation power are obtained. The function relationship between the above key parameters and arc conductance is established through parameter fitting, and then the improved Mayr arc of medium voltage distribution network cable grounding fault arc model is obtained. Finally, the reliability of the model is verified by comparing the simulation results with the measured fault current and voltage waveforms.