A New Symmetrical Three Phase Multilevel Inverter using Switched Capacitor Basic Units for Renewable Energy Conversion Systems

摘要

Due to increase in availability of renewable energy sources, development of multilevel inverter topologies has become an interesting research area for researchers in recent years to further improve the effectiveness of inverter systems. Multilevel inverter (MLI) with switched capacitor as the basic unit is a notable development in MLI topologies which reduces the number of power supplies required in comparison to the conventional MLIs and are widely known as switched capacitor multilevel inverter (SCMLI). In SCMLI, multiple power supplies can be replaced by capacitors which are used in tandem to boost the output voltage. Further, they possess capacitor voltage balancing capability. In this paper, a novel switched capacitor based three phase MLI for renewable energy conversion systems is presented using phase disposition PWM (PDPWM) modulation technique. The proposed three phase MLI is modular in nature and number of source modules can be increased to get more number of outputvoltage levels. A comparison study between the proposed topology and the recently developed three phase MLI topologies has been discussed in different perspective such as required components, maximum output voltage generation, capacitor voltage balancing capability etc. Further, an extensive simulation study is done in MATLAB/SIMULINK to validate the effectiveness and feasibility of the proposed topology.