T-type Inverter as a Power-Pulsation Buffer for a PMSM with Large Load Variation

This paper presents a modulation strategy for a three-level T-Type inverter to utilize the neutral point as a power-pulsation buffer. The pulsating power of a swing compressor is compensated by the buffer, resulting in dc input power of the motor inverter, despite the varying load. Consequently, the overall drive system can be designed with significantly reduced dc-link capacitance, saving cost and size. Next to theoretical derivation, the proposed modulation strategy is verified in simulation and experiment.