An Enhanced Cascaded Five-Level Inverter Based on Switched Capacitors and Single dc Source

Abstract

An alternative approach of the cascaded H-bridge inverter (CHB) in the form of an enhanced cascaded multilevel inverter is introduced in this paper. The proposed topology comprises two integrated switched-capacitor modules, an inductor and eight power switches, enabling the generation of five-level voltage with simply a single dc source. It has the capability for boosting the voltage as well as being able to exchange power on either side with reduced isolated source count. In this cascaded H-bridge multilevel inverter module, the capacitor charging phenomenon is independent of the load and the switching techniques developed are suitable to generate multilevel output voltages. Besides, the current spike issue for switched capacitors is found to be low in this topology. The output voltage enhancement and bidirectional power flow capability distinguish the proposed CHB multilevel inverter over other available technologies. Both simulation and experimental results are presented in the paper to validate the operational principle of the proposed bidirectional enhanced five-level cascaded H-bridge inverter (E5CHB).