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

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