An Optimization Method for Three-level Selective Harmonic Eliminated Pulse Width Modulation (SHEPWM)

摘要

This paper presents an optimization method and corresponding algorithm for three-level selective harmonic eliminated pulse width modulation (SHEPWM) strategy to improve harmonic performance of inverter's output voltage. Based on a three-level three-single-phase distribution static synchronous compensator (D-STATCOM), the principle of SHEPWM is introduced in the paper. Then, the conventional SHEPWM is divided into two different strategies, and two different sets of initial values are adopted for calculating switching angles. Furthermore, an optimization method is proposed, which brings better harmonic performance of inverter's output voltage with low switching frequency. Computational examples and experimental results both show that this optimization method has good convergence and good effect.