MAGNETIZING INRUSH CURRENT SUPPRESSION DEVICE

摘要

Provided is a magnetizing inrush current suppression device that is capable of accurately computing residual fluxes of a three-phase transformer and suppressing a magnetizing inrush current. The magnetizing inrush current suppression device (10) is equipped with: a voltage measurement unit (1) for measuring respective phase voltages of the transformer (23) and system voltages of the respective phases; an effective opening timing computation unit (2) for computing effective opening timing at which instantaneous values of the phase voltages of the three phases all converge to a value of zero; a core flux computation unit (3) for computing fluxes of the respective phases of the core of the transformer (23) by means of integration of the respective phase voltages; an effective residual flux computation unit (4) that takes, among the fluxes of the respective phases, the fluxes of the respective phases obtained at the effective opening point as effective residual fluxes in order to compute effective residual fluxes of the respective phases; a closing phase angle computation unit (5) for computing a closing phase angle for a system-side breaker (21) on the basis of the effective residual fluxes of the respective phases; and a closing phase angle control unit (6) for closing the system-side breaker (21) on the basis of the system voltages of the respective phases and the closing phase angle.