Method and device for suppressing parasite values contained in an output valves system of a control device and in a direct cyclo-converter with three-phase current output

摘要

The system produces an angle signal having a frequency that is a given multiple of the fundamental and defining, in a spatially fixed reference system, one coordinate axis of a coordinate subsystem rotating in the opposed sense to the fundamental formed and transformed into components in the subsystem by demodulation using the angle signal. The differences between averages of the transofmred vector components and desired zero are used to form the components of a correction vector in the subsystem. Back-modulation using the angle signal transforms the correction vector into the fixed reference system where it is used to produce a control vector.