VERFAHREN UND VORRICHTUNG ZUR REDUZIERUNG DES EINSCHALTSTROMSTOSSES BEIM BETREIBEN EINER INDUKTIVITAETSBEHAFTETEN LAST
A device (300a) is used to prevent inrush current when a load influenced by an inductance and a magnetizable core is connected to an alternating current power supply network, whereby a phase angle is provided at least at times. Thereby, during the simultaneous measurement of at least the reactive current in the load circuit, the rms voltage into the load is raised by increasing the voltage half-wave angle until a preset current threshold occurs. At this point, the magnetizable core is magnetized to saturation range. From this point, a voltage is applied to the load, said rms voltage being greater than and of opposite polarity to the voltage which caused the occurrence of the current threshold. This achieves a synchronization between the power supply a.c. voltage and the magnetization. The process is designed for initial turn-on and operation in pulsed group mode, and in particular for transformers. As a result, small-size transformers of correspondingly higher induction can be used at identical nominal power without large current peaks occurring at turn-on. Both single-phase alternating current and multi-phase alternating current can be used. With multi-phase alternating current, the individual phases are ... depending on the related switching group of the load in different ...
DE 1991-4108106 A: 19910313