PHASE CONTROL SWITCHING DEVICE

摘要

In a phase control switchgear for controlling circuit breakers connected between power supply-side transmission lines and compensating transmission l ines, any transient voltages and currents at closing of the circuit breakers are suppressed. There are included a voltage change rate zero-point-period determining part (31) that determines the zero point period of each of phase voltage change rates obtained by time differentiating phase voltages metere d by voltage metering parts (13R,13S,13T) adapted to meter the phase voltage s of the power supply-side transmission lines; a current zero-point-period d etermining part (32) that determines the zero point period of each of phase currents metered by current metering parts (21R,21S,21T) adapted to meter th e phase currents flowing through shunt reactors (20R,20S,20T) inserted in th e respective compensating transmission lines; and a closing phase control pa rt (33) that operates based on a closing command (40) for the circuit breake rs (10) connected between the power supply-side transmission lines and the c ompensating transmission lines and that generates, for each phase, such a cl osing phase that closes the respective circuit breaker at a zero point which is one of the zero points identical to both zero points of the voltage chan ge rate and those of the shunt reactor currentand at which both the polarity of the voltage change rate and that of the shunt reactor current reverse to the same polarity, thereby controlling the respective circuit breaker.