Space Vector Pulse Width Modulation for Asymmetric Flying Capacitor Three-level Inverter

Abstract

This paper proposes a 3-phase asymmetric flying capacitor 3-level inverter and studies its PWM performance. Firstly, the mathematical model and characteristics of this economical topology are described. Then, the space vector PWM algorithm is designed to control the output voltage, and the hysteresis comparator to balance the voltage of the flying capacitor is presented. Finally, simulation results under different load conditions have shown good output performance of the proposed asymmetric 3-level topology. Similar tests are also performed on both conventional 2-level and 3-level inverters for comparison. The obvious benefit of the asymmetric 3-level inverter is a fewer number of switches devices while it can achieve output performance similar to that of the conventional 3-level.