A Single-Phase Five-Level Inverter Topology for Distributed Sources

A five-level single-phase inverter topology suitable for distributed power sources is experimentally verified and compared to a conventional inverter topology. The basic unit of the inverter comprises a voltage-level generator and a classical H-bridge inverter. The voltage-level generator generates positive voltage levels while the H-bridge is used to generate the zero and negative voltage levels. The utilization of the phase opposition disposition (POD) and the alternative phase opposition disposition (APOD) PWM techniques on the five-level single-phase inverter is also presented. Suitable inverter switching gate signals are derived to generate the desired five-level output waveforms. The five-level operation presented in this paper can be extended to an n-level inverter. The functionality of the proposed topology is verified via MATLAB/Simulink simulations and tested experimentally using DC power supplies as the DC voltage inputs. Finally, the circuit was also tested using photovoltaic (PV) modules as the DC voltage inputs. The proposed topology produced lower THD values as compared to the conventional topology discussed.