High Frequency Grounding Analysis of Capacitor Bank Switching

摘要

The back to back capacitor bank switching phenomena has been the subject of many studies (1) (2) (3). This work demonstrates the need for a reliable grounding system for transients caused by capacitor bank switching to avoid insulation failures in a substation. When much of the work was done in analyzing the back to back capacitor bank switching phenomena, few tools were available to calculate ground grid voltage at high frequencies. Computer programs now availabel allow the engineer to determine voltage magnitudes caused by high frequency transietn inrush currents injected into a ground grid. The CEDGS program (4) was used in this study to analyze the buried conductor arrangement.In a paper by Daily and Dwalibi (5) the basic method of analyzing the back to back switching phenomena was fully developed. This study will describe two aspects of the problem: (i) How a sparse grid although adequately designe for step and touch voltage was not acceptable for ocntorlling high frequency overvoltages, and (ii) How a mesh design would reduce excessive voltages at different points in the ground grid.