Interleaved Discontinuous Space-Vector PWM for a multi-level PWM VSI using a 3-phase split-wound coupled inductor

A multi-level interleaved Discontinuous Space Vector PWM (DSVPWM) method is presented for a 3-level 3-phase PWM VSI using a 3-phase split-wound coupled inductor. The selection of a suitable pwm switching scheme for this topology is based on the dual requirements for a high quality multi-level pwm output voltage together with the need to minimize high frequency currents and losses in the coupled inductor and the inverter switches. Suitable switching states are described for the DVSPWM over the entire range of amplitude modulation depth. This pwm scheme minimizes the coupled inductor high frequency winding current ripple and also produces 3-level pwm output voltage waveforms at twice the inverter switching frequency. The inverter operation is examined using simulation tests. Extensive experimental test results are used to obtain the inverter performance as a variable frequency drive when operated in steady-state and during transient conditions.