Arc Modelling and Simulation Analysis of Resonant Grounding System with High Impedance Arcing Faults

U nderground cables are susceptible to chemical corrosion and physical damage from the surrounding environment, and often high impedance arcing faults occur at the interface. Fault characteristics are weak, conventional zero sequence protection actions fail, and fault detection is poor. Early arc dynamic model were based on the the principle of thermal equilibrium, and the arc voltage distortion is not obvious, so it is ineffectively to describe the whole combustion of the arc. To address this problem, this paper introduces the arc length variable based on the thermal balance principle of the traditional Mayr model, proposes an improved “cybernetic” nonlinear arc model, analyzes the nonlinear fault characteristics and waveform changes of high impedance arcing faults, and extracts the fault characteristics from the perspective of the frequency domain features by using the ensemble empirical modal decomposition method. The accuracy of the algorithm is simulated and analyzed under different fault conditions, and the simulation data proves that the fault model is more accurate than the traditional model, and the proposed detection algorithm has high reliability.