Design and simulation of a resonant full-bridge multicell power inverter for high-voltage applications

Abstract

The design and simulation of a Full-Bridge Flying-Capacitor Multilevel-Inverter (FB-FCMI) for high-voltage applications are presented. The power inverter topology consists of two legs: each one with three commutation cells, six switches and two flying-capacitors. The proposed control system provides twelve square signals for all switches that compose the inverter, which is driven at a commutation frequency fSW≈6.66 kHz. The output frequency f0, is equal to three times the commutation frequency. The inductor and capacitor in the resonant-circuit design is calculated based on f0, which depends on the number of cells, N. The goal of the proposed inverter design is to demonstrate that, the output frequency increases as rate of f0 = N∙ fSW. In order to show the effect of the increase in the number of cells, a resonant power inverter is designed and simulated, first with three and then with six switching cells, at f0 = 20 kHz. Finally, the FB-FCMI is connected to the primary winding of the high-voltage transformer, while the secondary is coupled to a Dielectric Barrier Discharge reactor represented by its electrical model, to generate an electrical discharge in helium.