Novel modulation strategy for a four-switch three-phase inverter

This paper presents a novel control switching strategy using direct flux vector modulation implemented in a single phase to three phase converter with only four switches in its DC to AC inversion stage. The modulation strategy maintains a constant circular stator flux by selectively switching among the four different nonzero voltage vectors, with the zero-state generated by turning on two opposing voltage vectors simultaneously. This scheme is implemented in real-time using microcontroller, with simulation and experimental results presented for verification.