Research On Failure Diagnosis Of Substation Grounding Grid

Substation grounding grid plays an important role in maintaining safe and reliable operation of power systems, and the existence of grounding grid can guarantee the safety of staff and electrical equipment. Grounding grids buried in the ground, and easy to be eroded by soil, resulting in the branch of the grounding grid tapering and even fracture. There will bring immeasurable loss to the power system If we can not Diagnosis of the grounding grid fault. Therefore of great significance for the study of the grounding grid fault diagnosis.This paper studies the fault diagnosis problem of the partial branch of substation grounding grid. Through in-depth study of the substation grounding grid fault diagnosis theory, reasonable simplifications and assumptions on the grounding grid, ignore the capacitance and inductance in each branch of the grounding grid equivalent to a purely resistive network. Incentives through the ground deflectors to inject a constant DC source, measuring the voltage value of the remaining ground deflectors, combined with the ground network topology, and the establishment of a grounding grid fault diagnosis incremental equation based on the electrical network theory. In order to effectively utilize the known ground deflectors, using the method of multiple transform the excitation position and each place inspire many measurement, Get the grounding grid fault diagnosis mathematical model based on the augmented matrix equations.The mathematical model of the grounding grids corrosion diagnosis established above is a non-linear equation. In-depth study on the problem of grounding grids corrosion diagnosis, proposed a new method for solving the problem of combination of grounding grids corrosion diagnosis based on the root of the query sequence algorithms and simulated annealing algorithm. The method to solve the grounding grids corrosion diagnosis underdetermined of the nonlinear mathematical model, greatly improving the diagnostic accuracy of the algorithm.In this paper, Using MATLAB software compiled grounding grid fault diagnosis software that based on the new algorithm which combined with the root of the order of queries and the simulated annealing algorithm. The software can be run independently from the MATLAB environment, and has a strong versatility.In this paper the application of PSCAD software to build simulation grounding grid, testing grounding grid fault diagnosis software through application of the above simulation of the grounding grid model; In addition, application field measurement data of a traction substation grounding grids for engineering testing the fault diagnosis software. Results show that the software can accurately diagnose the location of the fault branch in the grounding grid, and has a high diagnostic accuracy, that can avoid the process of fault diagnosis in the grounding grid inaccuracy and blindness, with a certain engineering value in use.