Enhanced Phase-Shifted Carrier PWM Applied to 3-Phase Multilevel Coupled Inductors Inverters

The use of coupled inductor inverters (CII) is attracting due of its several advantages as: 3-level output voltage, reduced number of controlled switches and no dead-time requirement. However, while using the conventional phase-shifted pulse width modulation (PS-PWM) shows low performance, space vector techniques presented in the literature requires a complex algorithm implementation. This paper applies an enhanced phase-shifted PWM (EPS-PWM) in order to improve quality of CII phase and line-to-line voltages, also the phase currents. The CII operation principles are discussed, and its performance using the PS- and EPS-PWM are compared in therms of voltage and current harmonic distortions. Simulations and experimental results are presented in order to validate the presented modulation performance.