Single DC Source Cascaded H-Bridge Inverter with Integrated Boost Capability

This paper proposes a new seven-level cascaded H-bridge (CHB), the innovation of which is that the topology has only one independent DC source and uses some capacitors to replace the DC source in the traditional cascaded H-bridge inverter. Part of the H-bridge is connected to the capacitor and one set of the H-bridge is connected to the DC source. The circuit integrates a boost circuit that charges the capacitor. When the circuit supplies power to the load/grid, the capacitor can be used as a DC source to supply power to the load/grid so that the output voltage of the inverter can be higher than the voltage of the DC source. In this paper, a unique modulation strategy and closed-loop control strategy are designed to ensure the charge-discharge balance of the capacitor and the quality of the output voltage and current. The topology using this strategy is simulated and analyzed in PSIM, and the results are discussed.