Power transformer switching-on current transient suppression system - pre-magnetises transformer core before switching to supply network with secondary load disconnected.

摘要

The current transient suppression system feeds a pre-magnetisation current to a transformer drive winding (3) having a defined phase relationship to an AC supply voltage. A load (9) is disconnected from the transformer secondary winding (8), with a signal delay stage for time-delayed connection of the transformer to the supply network (6, 7), relative to the pre-magnetisation. The load is pref. connected across the transformer secondary upon the transformer primary circuit attaining the load condition. ADVANTAGE - Relatively simple circuit preventing high switching-on current transients with high network loading.