Control equipment for a pmw modulated voltage source convector, and a method for controlling the same

摘要

A time-discrete pulse-width modulation control equipment for a voltage source converter, in particular a 3-level or a 2-level converter, has means (IREG) for generation of an AC-voltage reference template ( UV a R , UV b R , UV c R , UV €¾ abc R , UV €¾ ±² R ) for a voltage ( UV €¾ ) to be generated by the converter. The control equipment has first means (48) for determination of a sample period time ( Ts ) in dependence on an input signal representative of a frequency. The control equipment comprises phase-locking means (47) for synchronising the sample instants and the reference voltage template so that for a 3-level converter the phase positions 0° and 180° of the reference voltage template each coincide with a sample instant, and for a 2-level converter the phase positions 0° and 180° of the reference voltage template each coincide with an instant in time corresponding to a sample instant that is displaced in time with half the sample period time.