A Switched-Capacitor Multi-Level Inverter With Variable Voltage Gain Based on Current-Fed Dickson Voltage Multiplier

Abstract

A voltage boost switched-capacitor multi-level inverter (SCMLI) structure is planned which is able to control the voltage gain. The structure is based on Current-fed Dickson Voltage Multiplier (CFDVM). The CFDVM at the input stage limits the capacitor peak current and increases the voltage gain compared to other SCMLIs. Furthermore, high frequency operation significantly reduces the size of capacitors. The other main advantage is the same output impedance at all the voltage levels due to similar capacitor values and output current path. Selective Harmonic Elimination (SHE) technique is applied to improve output power quality. The operation principles and modulation strategy are described and the converter relations are derived. Also, the relations for component selection, capacitor voltage ripple and system efficiency are included. Comparative research of the suggested converter with similar state of the art converters is provided which shows that the proposed SCMLI has fewer power switches, gate drivers, and voltage sources. Furthermore, analysis of the cost function shows the economic nature of the proposed SCMLI. A 13-level laboratory prototype is built to verify the effectiveness of the suggested SCMLI.

Keywords

• Multi-level inverter
• switched-capacitor converter
• Dickson voltage multiplier