Synchronous Optimal Pulsewidth Modulation for High-Power AC Motor Drives: A Review

Electric vehicles require high-power machines, so reducing power loss becomes crucial. Compared to space vector modulation, synchronous optimal pulsewidth modulation (SOP) has several advantages in high-speed applications, like the capability to operate at a very low switching frequency with lower total harmonic distortion (THD), and reduced losses. This article presents a comprehensive review after performing a systematic investigation on different inverter topologies, including two-level (2L) voltage source inverters (VSIs) and multilevel inverter (MLI) topologies with SOP as the modulation scheme. Several optimal pulsewidth methods will be studied along with SOP design methods, including the steady state and dynamic switching. More emphasis is given to the various challenges faced in implementing SOP, followed by future trends.

I. Introduction

The growing demand for energy is driving the development of present-day high-power converter topologies to power various types of high-power systems. The main challenge in these systems is to limit the power loss. To achieve that, the switching losses should be reduced, thereby minimizing switching losses. However, this leads to high voltage and current distortions. One method for overcoming this is to develop appropriate modulation techniques because operation in switched mode is an efficient way to control power flow in a machine.