Research on Optimised Synchronous Space Vector Pulse Width Modulation Algorithm to Minimise Harmonic Current

One of the major concerns with regard to high-power traction inverters is the current harmonics that arise when working under the condition of low pulse ratios. To solve this problem, an optimized synchronous space vector pulse width modulation (SVPWM) was proposed to minimize root-mean-square (RMS) value of harmonic currents. On the basis of symmetry constraints of the output voltage waveforms in the traditional synchronous SVPWM, a generalized method was proposed to construct switching vector sequences. Using the constructed switching sequences set, the switching angle of a single vector sequence was optimized, and an overall optimization solution and system-level optimization selection were executed. Compared with the phase-voltage-oriented optimization pulse width modulation (PWM), the proposed optimized synchronous SVPWM algorithm can reduce 2/3 range of the solution set, and achieve convergence to the global optimal solution at any given initial value of the iteration, regardless of the initial value.