PV-Fed Eleven-Level Capacitor Switching Multi-Level Inverter for Grid Integration

This paper presents new photo-voltaic electrical power generation system, and this system consists of a DC (direct current)-to-DC power converter and multi-level inverters. This DC-to-DC converter combines a boost (step-up) converter and isolated converter (forward) with a coupled inductor to convert the output voltage of the solar panel fed PV array into different voltage sources. This eleven-level multi-level inverter is constructed using a full-bridge power converter and a capacitor selection circuit. These circuits are connected one by one, i.e. cascade. The capacitor selection circuit (CSC) is the combination of capacitor and transistor switches which helps to produce five levels of DC voltage from DC-to-DC converter output voltage. Then, H-bridge inverter converts this stepped level of DC power into AC power. By this way, the proposed solar power-fed eleven-level inverter produces a nearly sinusoidal output power and it produces very low THD which is less than twelve percentage. The important feature of this inverter is that only eight power electronics are used. The power produced from this multi-level inverter is same phase with the utility power.