A Filtered SVPWM for Multiphase Voltage Source Inverters Considering Finite Pulse-Width Resolution

A filtered space-vector pulse-width modulation (SVPWM) considering finite pulse-width resolution is proposed to produce a switching sequence with reduced baseband harmonics for multiphase voltage source inverters (VSI). The conventional SVPWM is sensitive to the pulse-width resolution which leads to increased harmonic distortion in digital-based implementations. By incorporating a pseudofeedback loop regarding weighted voltage difference between desired and produced phase voltages, the quantization error induced by finite pulse-width resolution is compensated, yielding a better tracking performance. The gating signals for multiphase VSIs are presented through rigorous mathematical derivation. In simulations and experiments, harmonic distortions of SVPWMs with and without filter compensation under various pulse-width resolutions are shown. The results confirm the effectiveness of the proposed scheme. The main advantage realized is reduction of acoustic noise and increased tracking accuracy.