Grid Integration of a Reduced Switching Loss Single-Source Boost Multilevel Inverter with Independent Control of Power Transfer and DC-Link Voltage

This paper presents a closed-loop control architecture of a grid-tied single-source multilevel inverter (MLI) with reduced switching loss, to control the DC-link as well as the power supplied to the utility system. The converter topology utilizes a diode-capacitor ladder network to facilitate a number of inherently-balanced voltages, which resolves the predominant constraint of MLIs having several separate dc sources. Furthermore, zero-voltage-switching (ZVS) is achieved for the solitary high-frequency switch, which mitigates the switching losses. High-frequency operation of the switch facilitates the reduced components size resulting in less cost and weight of the converter. An experimental set up for closed-loop control of the hardware prototype of the proposed converter has been developed. The performance of the grid-connected MLI is evaluated in various real-time conditions and the experimental results are presented.