GaN-Based Interleaved Totem-Pole Single-Phase Inverter with Coupling Inductor Design

Thispaper introduces and designs a 1kW GaN-based single phase inverter with interleaved totem-pole structure. The converter consists of three half-bridges, one of which is a low frequency bridge arm and the other two are interleaved-modulated high frequency bridge arms. By paralleling two high-frequency bridge arms, the root mean square of the current passing through each arm is reduced, thereby decreasing the conduction losses of the switching devices and the copper losses of the inductors. The inductors of two high frequency loops can be designed with planar coupling inductor, which simplifies two magnetic cores into one magnetic core, thereby reducing the volume and loss of magnetic parts. The inductors are designed with a planar configuration and utilize PCB windings, which effectively reduces the height of the magnetic components. The coupling inductor consists of two ferrite outer-legs and a powder core center-leg, for the magnetic flux will superimpose in the center leg, which may cause ferrite saturation. Finally, simulation and calculation results demonstrated the whole structure could have 99.2% peak efficiency.