ANALYSIS OF OVERVOLTAGES DUE TO CAPACITOR BANK SWITCHING and SURGE ARRESTER APPLICATIONS

摘要

Energization of high voltage shunt capacitor banks on power systems can create significant overvoltages both at the location of the switched capacitor bank and other locations in the power system. In many applications, shunt capacitor banks are often switched on a daily basis to maintain/control the system voltage levels during load changes. The shunt capacitor banks are installed at a substation that contains equipment already protected by surge arresters. The proper application of surge arresters near a shunt capacitor bank requires careful analysis of the power system, the switching devices and their arrangements, the insulation level of nearby equipment, the type of grounding and the arrester energy dissipation duty. This paper deals with the sudden voltage and current variations generated by switching of a capacitor bank in a 230kV substation of an Indian electrical system. The configuration of the system is studied and the ovevoltages are simulated using Electromagnetic Transient program. The field measurements of energizing and de-energising transients due to capacitor bank switching are compared with simulated values.