An alternative PWM scheme for multilevel voltage source inverter

Abstract

This work proposes an alternative PWM scheme for cascaded multilevel inverter. The scheme is based on symmetric regular sampled unipolar PWM, with multiple modulating waveforms and a single carrier. Mathematical equations that define the PWM switching instants are derived and implemented digitally using a low-cost microcontroller. A five-level cascaded multilevel inverter test-rig is built to prove viability of the proposed algorithm.