New model of corrosion diagnosis for grounding grids based on constrained total least squares algorithm

A discrepancy between the actual installation of substation grounding grids and the design drawings often leads to bigger error in the diagnostic results. Based on the traditional circuit method, the corrosion diagnosis algorithm is improved to take the corrosion characteristics into account, which means that the branches connected to the same node have the similar corrosion extent range. Therefore, an augmented linear model is proposed with localized difference corrosion index. And the best reduced-rank approximation theorem is adopted to ensure the compatibility of the equations. To solve the novel model, the total least squares algorithm is chosen to reduce the deviation carried by the disturbance factors in the model. The simulation results show the validity of this approach.