Phase-Shifting SPWM-Based Modulation for Single-Source Five-Level Current Source Inverter

A single-source five-level current source inverter (CSI) with inherent current balancing and fewer switches was recently proposed. Its modulation scheme that achieves both five-level output and superior harmonic performance with low switching frequency remains a challenge and has not yet been explored. Phase-shifting sinusoidal pulsewidth modulation (SPWM) is a well-established technique that offers superior harmonic performance at low switching frequencies. Despite these advantages, its application to the single-source five-level CSI is not applicable due to its unique single-source topology. In this work, the challenge associated with applying phase-shifting SPWM to the single-source five-level CSI is identified, and a novel phase-shifting SPWM-based modulation technique retaining all the advantages of phase-shifting SPWM is developed for the single-source five-level CSI. Lab-scale experiments are conducted to verify the performance.