Strategy and Implementation of Harmonic-Reduced Synchronized SVPWM for High-Power Traction Machine Drives
Lifan Xiao, Jian Li, Yongqian Xiong, Junhua Chen, Hongyang Gao
Abstract
High-power traction systems usually operate under low-switching-frequency conditions to avoid high switching losses. Synchronized space vector pulsewidth modulation (synchronized SVPWM) is an effective modulation method in low-switching-frequency modulation for its balanced harmonic performance and implementation complexity. A number of pulse pattern patterns in synchronized SVPWM are developed for application with different frequency ratios. In this article, the authors systematically analyzed the performance of pulse pattern and developed a harmonic-reduced pulse pattern selection strategy considering the influence of the modulation index. An implementation of synchronization SVPWM with strong universality is proposed, which includes a phase-locked loop (PLL) based synchronization method and pulse pattern transition strategy. The transition strategy can handle the transition for special-vector-sequence pulse patterns and over-modulation operation. The harmonic-reduced synchronized SVPWM strategy and its implementation are verified through simulations and experiments.