Reduced Switch Quadruple Boost Switched-Capacitor based Multilevel Inverter

Abstract

Switched-capacitor (SC) based structures are gaining a lot of popularity due to the simple natural balancing and voltage boosting features. However, to create a high-quality output, some of the existing structures require multiple dc sources and some requires a large number of switches with peak voltage stress. This is a major issue In PV application of the SC based multilevel inverters (MLIs). To get rid of these issues, this work introduces a new single input SC MLI that produces a 17-level output utilizing fewer components. The proposed structure utilizes a new SC unit and only three capacitors are required that assists in quadruple voltage boosting by maintaining the desired voltage across it. Without any voltage balancing control scheme, the capacitor voltages are naturally balanced. i.e., two capacitors in the SC unit are charged to half of the input voltage magnitude and the other capacitor is charged to twice the input voltage magnitude. In addition to this, the stress across the switches and the capacitors is confined to twice the source voltage. Followed by a thorough comparison with the existing 17-level structures, simulation and experimental test results under dynamic operating conditions are provided to validate the functionality of the proposed SC MLI.