An Experimental Assessment of Multi-Objective Pulse Pattern Optimization for Synchronous Machine Drives

Abstract

This paper investigates the impact of optimized pulse patterns (OPPs) on the efficiency of two-level voltage-source inverters (VSIs) and permanent magnet synchronous machines (PMSMs) using a machine test bench. Due to the complex behavior of iron losses in electrical machines, proxy metrics such as current total harmonic distortion (THD) are commonly used to accelerate the computation of OPPs. A multiobjective optimization framework is applied to design OPPs with non-restricted half-wave symmetry, balancing the conflicting objectives of minimizing switching losses and current THD. The optimization yields a Pareto curve in a two-dimensional solution space, providing pulse patterns with minimum THD, minimum switching losses, or a compromise between both. Experimental measurements are conducted to evaluate the correlation between the proxy-based optimization objectives and the actual efficiency of the VSI-PMSM system. The results indicate that the Paretooptimal trade-offs identified using simplified offline models and proxy metrics can, to a certain extent, be reproduced experimentally.