A Novel 5-Level 2x-Boost Switched Capacitor Based Inverter with Common-Ground Feature

This paper proposes a novel switched capacitor based five-level inverter with a two-fold voltage gain and common ground (CG) feature. This common ground feature nullifies the leakage current, which makes it suitable for grid-connected photovoltaic (PV) applications. The semiconductor devices in the proposed inverter comprise six switches and one diode, which is low compared to its counterparts. The existing CG-based five-level inverter topologies comprise capacitors rated for twice the source voltage, reducing power density. However, in the proposed inverter, the capacitors are rated for source voltage, which improves the power density and reduces the cost. Capacitor voltages are self-balanced, eliminating the need for a voltage-balancing sensor. Further, a thorough comparison with existing five-level two-fold gain CG-based topologies has been carried out, which shows the merit of the proposed inverter in terms of component count, capacitor voltage rating, total standing voltage, cost factor, and maximum blocking voltage. The modes of operation, modulation scheme, and closed loop grid-connected control scheme are presented. The proposed inverter is simulated using MATLAB Simulink, and the hardware-in-loop test is performed on OPAL-RT 4510 for various steady-state and dynamic conditions, showing the proposed inverter’s efficacy.