The　new　three　phase　VFVA　sine　wave　generator　is　presented　in　this　paper.　A　new　sampling　holding　three　phase　VFVA　sine　wave　generator＇s　pcinciple,　circuit　and　experimentation　waveform　are　introduced.　The　principle　of　this　sampling　holding　circuit　is　simple　and　the　realization　of　har＇dware　circuit　is　easy.　Here　we　describe　the　three　phase　reference　sine　wave　which　is　produced　by　this　generator＇s　circuit　and　is　required　by　PWM　inverter　is　described　in　this　paper,　and　also　introduced　the　speed　control　and　harmonic　analysis　of　PWM　inverter　variable　frequency.　©　1994　Science　Press.