PWM hybrid inverter drive circuit topologies that employ a dual voltage and current DC-link

A three-phase hybrid inverter drive circuit topology, suitable for high-power applications, that supplies the output inverter with a dual DC link consisting of a constant current and a constant voltage is described. Four basic hybrid drive types are described: freewheel diode, buck, boost, and the pulse-width-modulated rectifier. The resultant drive topologies combine with current overload protection features associated with a current source inverter together with the high performance associated with a PWM voltage source inverter. Three-phase schemes are investigated to show that the output inverter bridge can be used to control the DC-link voltage and the DC-link current without interfering with the PWM voltage waveforms fed to the motor. Computer stimulations and experimental results are used to demonstrate the operating features of the various drive types.<>