Control of a Naturally Commutated Inverter-Fed Variable-Speed Synchronous Motor

This paper describes the design and construction of the control circuits of a naturally commutated current-source inverter feeding a synchronous motor to give a variable-speed drive. The main contributions of the paper deal with the circuits required to control the inverter from rotor position, and to control the system for all modes of operation including regenerative braking. The performance of a prototype is illustrated by test results and recordings.