Patent ID: 6166930
Filing Date: 2000-12-26
Classification: H02M,H02P

Abstract:
A method of controlling the flow of current through a DC matrix converter between a DC load and a set of three-phase AC mains, said DC matrix converter comprising a plurality of top switches, each connected between a corresponding one of said AC mains and a first DC output of said DC matrix converter, and a plurality of bottom switches, each connected between a corresponding one of said AC mains and a second DC output of said DC matrix converter, comprising:operating said switches in a manner so that each switch, when operated to connect a corresponding one of said AC mains to a related specific one of said DC outputs, remains operated until another switch has operated to connect one of said AC mains to said specific DC output, and so that one of said top switches is operated contemporaneously with one of said bottom switches, said switches being operated in pairs, each pair including a top switch related to one AC main and a bottom switch related to an AC main other than said one AC main, and said switches also being operated in sets, each set including a top switch and a bottom switch both related to the same AC main;in each of a continuous sequence of modulation periods which are small compared with the period of voltage of said AC mains, operating a first pair of said switches for a first fraction, d.alpha., of said period, operating a second pair of said switches for a second fraction, d.beta., of said period, and operating a set of switches for the remainder of said period; andselecting said set of switches in any modulation period to be a set related to a selected AC main for which the line-to-neutral voltage of said selected AC main is less than the line-to-neutral voltage of the other two of said AC mains.