Three-Level Inverter Based on Switched Capacitors and Modulation Strategies

To meet the high power density requirements of multi-level inverters in new energy vehicles or energy storage systems, this paper proposes a component-reduced, boost-capable switch capacitor-type three-level inverter. This topology consists of a switch capacitor circuit and an inverter full bridge circuit, where the switch capacitor circuit generates multiple levels and boosts the DC source voltage, while the full bridge inverter circuit handles the inversion. Additionally, the use of SVPWM modulation strategy to control the switching of the switches achieves capacitor voltage self-balancing, resulting in a DC voltage conversion ratio three times higher than traditional two-level inverters. Finally, a simulation platform is constructed to verify the steady-state and dynamic performance of this topology, demonstrating the effectiveness of this inverter.