Three-phase three-level voltage source inverter with low switching frequency based on the two-level inverter topology

A new configuration of the three-phase three-level voltage source inverter has been presented. The proposed inverter is based on the two-level inverter. The inverter is built of one two-level conventional inverter, an auxiliary circuit which comprises of three bidirectional switches, and two bulk capacitor banks. A selected harmonic elimination control scheme is employed to achieve lower harmonic contents in the inverter output waveforms. Two-level inverter switches operate at the line power frequency (50 Hz) whereas the auxiliary circuit switches operate at twice line power frequency (100 Hz). To validate the proposed inverter, a low power prototype inverter has been designed and implemented; analytical, simulation and experimental results have been provided.