A new approach to generate PWM patterns for four-switch three-phase inverters

This paper presents a new method to generate pulse width modulated signals to control four switch three phase inverters. The proposed method provides a simple scheme to select three or four vectors to synthesize the desired output voltage. The method is based on the so called space vector modulation but the paper also presents its scalar version. The paper presents a comparative study where the different vector combinations are investigated. The paper also discusses how the use of the wye and delta connections of the machine windings affects the implementation of the pulse width modulator. Simulation and experimental results are presented to corroborate the analytical developments.