Digital signal processor controlled auxiliary commutated pole converter for high-performance motor drives applications

Resonant and soft-switched inverter drives offer the potential for increase d switching frequencies, reduced weight and lower levels of electromagnetic interference when compared to conventional hard-switched drives. Regrettab ly, low-cost, soft-switching topologies such as resonant link designs suffe r from poor control performance while others, such as the ACPI, have a high component count and relatively complex control structures. A low-cost comm utation control scheme is proposed for the ACPI, which uses a digital signa l processor to determine the optimum switching instants for both auxiliary and main devices. Results are presented comparing the performance of the DS P controlled ACPI with an equivalent hard-switched converter.