Linearization Of the Multi-Level SVPWM in the Over-Modulation Region

Abstract

A multi-level PWM signal generation with linear transfer characteristics between fundamental component of output voltage and modulation index in the entire modulation range including over-modulation is proposed in this paper for any n-level SVPWM signal generation. The reference signal to the PWM modulator is pre-scaled in over-modulation region such that the fundamental component of the original and the modified reference signal is same. The principle of pre-scaling the reference signal is first derived for two-level PWM and then its extension the n-level SVPWM is proposed. A five-level inverter configuration, using an open-end winding induction motor drive, is used for verifying the SVPWM generation scheme, experimentally.