Patent ID: 9170597
Filing Date: 2015-10-27
Classification: G05F,H01H,H02H

Abstract:
1. An inrush current suppressing device applied to a configuration in which a breaker is connected between a power supply and a transformer, the inrush current suppressing device suppressing an excitation inrush current in the transformer associated with a closing operation, the inrush current suppressing device comprising: a power-supply-voltage measuring unit configured to measure a power supply voltage on a side of the power supply of the breaker; a residual-magnetic-flux calculating unit configured to retain an interruption characteristic in an opening process of the breaker and an attenuation characteristic of a magnetic flux of the transformer after current interruption, calculate a magnetic flux value at a time of current interruption based on the power supply voltage and the interruption characteristic, and calculate a residual magnetic flux value based on the magnetic flux value at the time of current interruption and the attenuation characteristic; a turn-on-phase calculating unit configured to calculate a power supply voltage phase where the residual magnetic flux value and a steady magnetic flux value at a time of application of the power supply voltage match and set the power supply voltage phase as a turn-on power supply voltage phase; and a control unit configured to control closing of the breaker such that the breaker is turned on in the turn-on power supply voltage phase.