PULSWEITENMODULATIONSVERFAHREN FÜR IN SERIE GESCHALTETE UMRICHTER

摘要

The method involves combining voltage pulses (U1,U2) of first and second converters with first and second degrees of modulation (m1,m2) so that a common voltage pulse (U1+U2) without gaps is produced. Preferably, during generation of the pulse width modulation using an undershoot method, the carrier signal of the first converter is shifted through an angle alpha with respect to the unchanged carrier signal of the second converter, where alpha is + or - half the sum of the degrees of modulation times 180 degrees. The combined voltage pulses are symmetrical to the previous and following combined voltage pulses. The carrier signals of the first converter with the first modulation degree are shifted by a first angle and the carrier signals of the second converter with the second modulation degree are shifted by a second angle.