A Switched-Capacitor-Voltage-Doubler Based Boost Inverter for Common-Mode Voltage Reduction

Abstract

In this paper, a modified three-phase two-level voltage source inverter is proposed. By combining the conventional three-phase H-bridge inverter with a switched-capacitor-voltage-doubler network, the DC-link voltage of the proposed inverter is double with respect to the input DC voltage. As a result, the output voltage of the proposed inverter can be higher than the input DC voltage. Furthermore, a common-mode voltage (CMV) of the proposed inverter can be reduced through controlling the two additional switches based on the space vector pulse-width modulation. Compared to the existing modulations and topologies, the variation in CMV can only be up to 16.6% of DC-link voltage. Furthermore, the voltage stress across additional switches and diodes is equal to half of DC-link voltage. Mathematical analysis, operating principles, and comparison of the proposed three-phase two-level voltage source inverter with the conventional three-phase voltage source inverters are presented. The simulation results based on PLECS software verify a good performance of the proposed inverter. Finally, a laboratory prototype based on a TMS320F280049 DSP is developed and experimental tests are carried out to validate the effectiveness of the proposed three-phase inverter topology.

Keywords

• Three-phase inverter topology
• common-mode voltage
• transformerless PV system
• space-vector pulse-width modulation
• leakage current