| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an excitation inrush current suppression device which can control the closing phase for suppressing the excitation inrush current of a circuit breaker which opens or closes connection between a three-phase AC power system equipped with a power supply and a transformer which converts three-phase AC voltage to single-phase AC voltage. <P>SOLUTION: In an excitation inrush current suppression device 6 which suppresses the excitation inrush current of a circuit breaker 2 of three-phase bath operation type which opens or closes connection between a power supply busbar 1 and a transformer 3 with effectively-grounded transformed wood bridge wiring, three-phase AC voltage of the power supply busbar 1 is measured, the steady magnetic flux of the transformer 3 is calculated, three-phase AC voltage on the transformer 3 side is measured and the residual magnetic flux of the transformer 3 after cut-off is calculated, and then, when the steady magnetic flux and the residual magnetic flux have their polarities matched in all phases, the circuit breaker 2 is closed. <P>COPYRIGHT: (C)2013,JPO&INPIT |
