Optimized Predictive Control of Hybrid Multilevel PV Inverter with Reduced Leakage Current

This paper proposes a modified multilevel hybrid photovoltaic (PV) inverter that utilizes optimized model predictive control (MPC). The optimized MPC facilitates intelligent selection of voltage vectors to minimize the computations necessary to reach lower potential leakage current compared to traditional modulation schemes. The cascaded H-bridge based topology is modified with two extra switches to decrease the leakage current. A capacitor is employed to generate multilevel output while also instilling voltage boosting capacity. The multilevel output further ensures that the filter inductor required to connect the grid to the inverter is smaller in size than the present state of the art whereas the boosting ability enables the inverter to connect to grid at higher voltages while eliminating the transformer. The control uses on MPC, which has the advantage of eliminating any sophisticated cascaded control. The modified topology and optimized MPC control are tested by simulations and on a 500-watt prototype to validate its effectiveness.