A Single-Source Multilevel Inverter with Boosted Output Voltage for Solar PV Applications
Ali Mohammad, Mohammad Tayyab, Adil Sarwar, Muhammad Khalid
Abstract
This paper presents a nine-level structure with fewer switches and four times boosting. The switched capacitors are employed to generate required levels at the output ports of the inverter terminal. 11 switches, two capacitors and one diode are employed. The capacitors are self-charged through parallel paths. The first capacitor charges to V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dc</inf> , and the other to 2V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dc</inf> by paralleling it with the first capacitor and the DC-source. The inverter states are chosen so that the output is a 9-level voltage with a peak of four times the DC-source applied. This converter is beneficial for Solar PV applications in microinverter applications due to fewer switches and small filter requirements. Moreover, the boosting capability mitigates the requirement of an additional DC-DC boost converter. The presented inverter operation is verified in Simulink and validated on the laboratory prototype.