Three-Level Optimized Pulse Patterns with Zero Common-Mode Voltage

Abstract

This paper investigates the computation of three-level optimized pulse patterns (OPPs) with zero common-mode voltage (CMV). To do so, a set of linear constraints that guarantee zero CMV is derived, and a systematic way of implementing it is presented. Moreover, to alleviate the increased computational demands of the associated optimization problem, a method that can reduce the computational time of three-level OPPs with zero CMV by up to 99% is proposed. Finally, to mitigate the increased current harmonics due to the CMV elimination, the symmetry requirements of the OPPs are relaxed. In doing so, as shown by the presented numerical results, the current quality can be improved, but alas, only marginally and over a limited range of modulation indices.