Verfahren zum Unterdruecken eines Einschaltstromstosses beim Anschalten eines Leistungstransformators
The core (2) of an idling power transformer (1) is premagnetizable via a current limiting device (100) by means of a premagnetizing current in the driver coil (3) corresponding in general to the idling current of the power transformer (1) at a much lower power than the current drain of the power transformer (1) in load mode in a prescribed time sequence. The power transformer (1) is offset in time compared with the premagnetization by means of a signal delay circuit (57) and is switchable in idle by a switching unit (26, 27) to the power supply network (6, 7) in load mode in an uncritical phase without inrush currents occurring. The current limiting device can also consist of a pretransformer with which smaller switching voltages are generatable at a high supply alternating current.
DE 1993-4309484 A: 19930324