New three-phase multilevel voltage source inverter with low switching frequency

This paper proposes a new multilevel circuit topology for a three-phase voltage source inverter. The inverter is built from the conventional three-phase full bridge configuration with the addition of five bidirectional switches. With this inverter, seven levels in the output line-to-line voltage waveforms are obtained. The operational principles of the inverter with low switching frequency are analyzed in detail. For verification, computer simulation has been carried out and hardware testing on a prototype inverter with the control algorithm implemented on a TMS320F2812 digital signal processor has been conducted.