A novel forward-mode five-level inverter with high frequency link

Compared with the three-level inverter, the five-level inverter has more prominent characteristics, such as the higher output voltage, the higher output power and the lower voltage harmonic content. Therefore, it has the higher research value in the field of high voltage and high power. In order to improve efficiency, ameliorate waveform, achieve high frequency and realize the capacitors voltage balance in each switching cycle, a novel forward-mode five-level inverter is presented, so that each level of the filter inductor front has a plurality of switch states corresponding to it, more flexible control. At the same time, this paper proposes a voltage equalization strategy based on transient voltage feedback control strategy, to solve the problem of the capacitor voltage imbalance. Through calculation and comparative analysis, it is found that the harmonic content in the front-end of the filter has been greatly reduced, and the requirements of the filter are reduced obviously. The filter volume is reduced and the power density is increased. Finally, the feasibility of the topology and the effectiveness of the equalization strategy are confirmed by simulation and experimental results.