Variable Frequency AC Motor Controller Using MCT's

A power controller is described which has increased power capability (50-100 Hp range), improved efficiency, reduced cost, and increased control capability for control of onboard auxillary power sources. A full four-quadrant control inverter uses a variable frequency, quasi-resonant four-quadrant H-bridge configuration and a phase shifted PWM controller for control of a three phase AC induction motor. Use of second generation P-MCT's improves inverter efficiency. Phase controlling the motor as a two-speed transmission. A custom hybrid microprocessor based system controller gives the desired control capability in a small, low cost, low weight, package suitable for volume production. ANTICIPATED BENEFITS: The single stage inverter concept offers a performance advantage (low loss, reduced parts count) and has wide application in motor control for electric vehicles, tanks, all electric aircraft and multifunctional switching in Navy and Marine power systems.