Protective system for a high‐power capacitor bank

Abstract

AbstractA new protection system for capacitor banks in the case of a short‐circuiting accident is described. A pulsed power system composed of many capacitor units and closing switches is well known for producing a controlled pulse current of high power as for the power source of a plasma experimental device, etc. According to the increase of capacity of a bank system, it becomes important to protect the whole bank system from a short‐circuiting accident in a capacitor unit.Although some protective ideas have been proposed, these conventional ideas have not been sufficient to absorb the energy flowing into the failure unit from other normal units. Constructing the new 1‐MJ capacitor bank for a plasma experimental device, a newly conceived protective device is designed. The new protection system can absorb the bank energy and suppress the short‐circuiting current flowing into the failure capacitor units, and overcomes the defect in former protection systems. To confirm the utility of a new protection system, a test of a protection resistor imitating the actual bank circuit was made. The test result showed that absorbable energy for the unit ceramic resistor amounted to 1500 Joule/cc. The new system is adopted to the bank system of the TPE‐1RM15 plasma experimental device.