Comparison of SVPWM for five level NPC H-bridge inverter and traditional five level NPC inverter based on line-voltage coordinate system

Two types of five-level inverter topology structure will be discussed in this paper: traditional five-level NPC inverter and five-level NPC H-bridge inverter. Except for the comparison of the two topology structures, the closed-loop control method of the neutral point balancing of the five-level NPC H-bridge inverter will be presented in the paper. For the modulation method of two five-level inverters, the traditional SVPWM won't be used. In order to simplify the calculation, SVPWM based on line-voltage coordinate system will be used. At the end of paper, the simulation results of the two topology structures will be presented when the frequencies of the reference voltage vector are different with the load of resistance and inductance or synchronous motor.