Modeling and Application of Ring Return Electrode for Impulse Test of Transmission Tower Grounding Device

The selection of the return path in impulse test of transmission tower grounding device is significant for the optimal design of grounding device and the safe and stable operation of the power system. In order to find out the optimal layout of the ring return electrode, the optimal layout determination process is established. Simultaneously, a test parameter calculation model in consideration of the ring return electrode is established, the correctness of the model is verified by finite element simulation. The proposed model is used to analyze the measurement error and the optimal radii of the ring return electrode for different test targets are studied. Studies have shown that: The application of the proposed calculation model and process can determine the optimal layout of the ring return electrode automatically and quickly, eliminating the trial of the impulse test and complexity of a large number of simulations, which greatly reduces the labor consumption and time cost, and completes the design task in test planning phase efficiently and accurately; the optimal radius of the return electrode increases with the increase of the farthest target measuring distance, and there exists a clear linear relationship between the above parameters.