A Detection Method for Fast Electrical Impedance Imaging of Grounding Grid Based on Optimized Differential-Multigrid-Homotopy Algorithm

Efficient electrical impedance imaging fault detection in grounding grid is necessary. In this article, we propose an optimized differential-multigrid-homotopy (MG-HT) algorithm for grounding grid impedance imaging. To enhance the iteration speed, we introduced an optimized differential algorithm to obtain the Jacobian matrix and derive calculation methods for the 2-D constraint operator and interpolation operator. Moreover, we utilize multigrid fast iteration and HT methods simultaneously to improve the rapidity and ill-posedness of the inverse problem. We validate the proposed algorithm through numerical simulations and experimental studies. First, we verify the time and convergence of the optimized differential algorithm for solving the Jacobian matrix. Second, we investigate the CPU time and convergence of image reconstruction based on the Tikhonov algorithm, HT algorithm, and MG-HT algorithm under different ground grid fault scenarios and noise levels. The simulation and experimental results show that the optimized differential-MG-HT algorithm has better robustness and convergence.