CONTROL METHODS FOR THE SYNCHRONISATION AND PHASE SHIFT OF THE PULSE WIDTH MODULATION (PWM) STRATEGY OF POWER CONVERTERS

摘要

The present invention provides a method of controlling a plurality of powerconverters 1a, 1b and 1c that can be used to interface to a supply network, acbusbaretc. Each power converter includes a network bridge 14 operating in accordancewitha pulse width modulation (PWM) strategy having the same switching period andwhich causes at least one unwanted harmonic in the supply network voltage. Themethod includes the step of providing the switching period of the PWM strategyofeach network bridge with a different time offset relative to a time datum suchthat theat least one unwanted harmonic in the supply network voltage is at leastpartiallycancelled. Two alternative ways of providing the time offset are described.