TRANSPUTER-BASED HARMONIC-ELIMINATION PWM CONTROL OF INVERTER DRIVES

New harmonic-elimination PWM strategies for VSI and CSI drives have recently been developed using modified regular-sampling techniques. These new PWM strategies can be generated on line in real time using a simple microprocessor software algorithm without resorting to the usual off-line mainframe computer harmonic elimination numerical techniques. These new PWM techniques can be used over the complete voltage/frequency range of the drive up to and including the transition from PWM to quasi-square wave (QSW) operation. The implementation and generation of these new PWM techniques using the new parallel-processing INMOS transputer will be presented and the concurrency programming ability of the transputer for PWM generation emphasized. The implementation of the new PWM strategy can also be performed on any standard 8- or 16-b microprocessor using 4 or 1 timer implementations, as demonstrated. Results from an experimental transputer-controlled PWM inverter drive are presented to demonstrate and confirm the special feature of the new regular-sampled harmonic-elimination PWM control strategies.