Microprocessor Control of an Induction Motor with Flux Regulation

This paper describes the speed control system of an induction motor drive using a Motorola 6800 microprocessor as a control unit. The drive employs slip frequency and flux regulation for improved performance of the induction motor and a current source inverter for ruggedness. The software and hardware structure for the microcomputer control system are described. The constant airgap flux control scheme is implemented by storing a slip frequency-motor current lookup table in the computer memory. Experimental results obtained from a test model are presented. The drive allows a wide range of operating speeds.