Circuit arrangement for inductive three-phase loads, especially three-phase drives

摘要

The invention relates to a circuit arrangement for inductive three-phase loads, especially three-phase drives, which is operated via an invertor in a three-phase bridge circuit and via an upstream DC intermediate circuit, the supply being effected via a DC controller from a DC network with a network capacitor. In order to improve the recovery and in order to reduce the voltage load on the components such as valves, capacitors and motor it is proposed to connect a rectifier bridge (15) to the three-phase connections of the invertor (WR), which bridge feeds back to the network capacitor (CN) via a parallel-connected buffer store (CKap), it being possible to set the mean voltage value on the buffer store (CKap) via short-circuiting DC controllers. Further advantages are a considerable reduction in the weight and the volume of the capacitors required and a reduced adjustable voltage load on the elements, with an extended frequency adjustment range of the valves. <IMAGE>