A Step-up Multilevel Inverter Structure using Switched Capacitor technique with Non-isolated Power Sources and Reduced Devices

摘要

With growing demand for green energy such as solar energy, multilevel inverters are the focus of research due to their adequate cost, compactness, and high efficiency. A novel 9-level multilevel inverter (SCMLI) topology based on switched capacitor technique is presented first. The structure utilizes 2 non-isolated power sources and reduced components to realize higher number of output voltage levels. The structure has the ability to produce boosted output voltage from lower voltage input. Further, it can balance the capacitor voltages using simple switching states. In addition, the structure does not use H-bridge circuit for polarity generation which reduces total standing voltage of the structure. Phase disposition high frequency modulation strategy is used to switch the inverter. To validate this SCMLI, simulation study for 9 voltage levels has been carried out considering different kinds of load conditions. For this proposed SCMLI structure, an extended structure has been developed, which can cost effectively produce as much voltage levels as possible with least circuit complexity.