Model Predictive Control for An Improved Transformer-less Five-level PV Inverter Topology

Power inverters have been located at the heart of photovoltaic (PV) applications. Transformer-less inverters possess several benefits over transformer-based PV inverters such as low volume, low cost, and higher effectiveness due to not use a transformer. This research introduces an improved 5-level transformerless inverter to apply in a single-phase grid-connected PV system. The proposed topology due to the use of a flying capacitor in its circuit can boost PV voltage like a DC-DC converter without using passive elements. To control the system a Finite Control Set-Model Predictive Control (FCS-MPC) is presented to evaluate the performance of the proposed inverter. The simulation results show that the presented FCS-MPC has a good performance during environmental disturbances in transient and steady-state operations in terms of grid current and PV current control as well as capacitor voltage control.