Drive Circuit For Electrical Load

摘要

A circuit for an electrical load comprises a passive transformer, the secondary of which is connected to power cells for each phase according to the transformer tappings. Each power cell comprises a low cost but efficient power factor correction circuit to produce lower harmonics on the transformer.

主权项

1. A drive circuit for an electrical load comprising: a multi-tap transformer, a set of switchable power cells connected to the output of the or each phase of the transformer for the or each tap, each power cell being switchable to provide electrical power to an output of the circuit, each power cell comprising a rectifier circuit having an AC input and being connected across serially connected DC link capacitors, an inverter connected across the DC link capacitors and a bi-directional switch connected from the DC link capacitors to between the or each phase of the AC input.