Magnetizing inrush current suppression device and suppression method therefor

摘要

This magnetizing inrush current suppression unit (6) measures respective phase voltages of single-phase alternating-current-side buses by means of a bus voltage measurement unit (601), and single-phase-side voltages of a transformer by means of a transformer voltage measurement unit (603). With a phase detection unit (605), the magnetizing inrush current suppression unit (6) detects a shutoff phase, that is, a phase detected when a switch (2) is shut off by being opened, from the respective phase voltages which are measured by the bus voltage measurement unit (601) and the single-phase-side voltages which are measured by the transformer voltage measurement unit (603), retains the shutoff phase, and obtains a phase which is identical to the retained shutoff phase. Through a close command output unit (606), the magnetizing inrush current suppression unit (6) closes the switch (2) on the single-phase alternating-current side at a voltage phase identical to the phase obtained by the phase detection unit (605).