Simulation study of resonant DC link inverter for current-controlled switched reluctance motors

The paper presents a functionality study of the switched reluctance motor (SRM) inverter utilising a resonant DC link (RDCL) with and without an active clamp (ACRDCL) to provide current regulation with zero-voltage switching. By simply synchronising the switching instants in the SR inverter to the resonant link zero voltage periods, high bandwidth delta-modulated current regulation, necessary in high-performance SR drives, is performed with minimal switching losses. The classic 2-switches-and-2-diodes-per-phase inverter configuration is maintained. The normal operating modes of current-regulated SRM drives are simulated and comparisons between hard-switched and soft-switched waveforms are presented. The simple operation of the circuit is validated and found to maintain all performance and robustness aspects of the hard-switched inverter drive, albeit the soft-switching adds some control requirements. It is concluded that the presence of soft-switching does not compromise the drive performance compared to hard switching in any aspect. Similarly, applying the resonant link to the SRM inverter presents no difference compared to AC-drive applications.