On three-phase six-switches voltage source inverter:: A 150○ conduction mode

This paper presents a new modification for the most-common, simple, and well-known three-phase voltage source inverter (VSI). In this modification, each one of the six transistors conducts for 150 degrees instead of the usual 180 degrees or 120 degrees conduction modes. For a wye-connected load, the output phase-voltage becomes a seven-level, 12 Steps waveform- which is closer to the sinusoidal waveform- than the 6-step one. This results in a 50% reduction of the total harmonic distortion (THD), 75% reduction of voltage distortion factor (DF), and the lowest order harmonic (LOH) becomes 11 rather than 5. A comprehensive study for the three modes of conduction is proposed, and a comparison with other types of VSIs, like the neutral point clamped (NPC) and the multilevel inverters (MLI) is also carried out. Simulation and experimental results show the contribution of the proposed strategy.