A Seven-Switch Current-Source Inverter Using Wide Bandgap Dual-Gate Bidirectional Switches

Abstract

Conventional current-source inverters (CSIs) using silicon-based reverse-blocking (RB) switches typically suffer from high conduction loss, low switching frequency, and bulky size. New bidirectional (BD) switches (also called four-quadrant switches) built from wide bandgap semiconductor materials such as gallium nitride and silicon carbide offer both reverse-voltage-blocking capability and low conduction loss that make them appealing candidates for increasing the CSIs efficiency. This article proposes a new modulation scheme for an emerging three-phase CSI topology (H7-CSI) to enable it to operate safely with BD switches to achieve higher efficiency (as much as 3%) compared to the conventional H6-CSI topology or the emerging H7-CSI using RB switch. In addition, this modulation strategy combined with the proposed H7-CSI-BD topology is capable of significantly reducing the conducted common-mode (CM) EMI up to 20 dB⋅μV. Based on this improvement, a promising CM EMI filter network consisting of a CM choke and Y-capacitor has been designed for the H7-CSI-BD topology to meet EMI standards. The required filter component values for the H7-CSI-BD topology are significantly lower than those required in conventional CSIs. Analysis, simulation, and experimental results are provided that confirm the advantages of the proposed BD switch-enabled H7-CSI over conventional H6-CSI and emerging H7-CSI topologies using RB switches.