OPENING/CLOSING DEVICE FOR PHASE CONDITIONING EQUIPMENT

PURPOSE: To suppress the rush current which flows when the capacitor bank of the opening/closing device of phase modifying equipment which opens/closes the electrical circuit connecting a capacitor bank circuit composed of a capacitor C and reactor which is connected in series with the capacitor C to a power source is turned on and, at the same time, to relieve the di/dt. CONSTITUTION: A reactor l is constituted of a reactor having a capacity which is 15-18% of the capacitance of a capacitor and a switch 2 is connected in parallel with the reactor. The switch 2 is closed when resonance quiets down after a circuit breaker CB is turned on. The rush current which flows when the circuit breaker CB is turned on is remarkably suppressed as compared with the conventional example, because the rush current becomes about 2.6-2.36 times as large as a rated current. Since the resonance frequency becomes lower, in addition, the di/dt at the time of turning on the circuit breaker CB is remarkably relieved. When the switch 2 is closed, no voltage drop occurs, because the reactor l is short-circuited. Therefore, the whole capacitance of a capacitor contributes to the improvement of the power factor.