Mutual Control of Interleaved and Single Phase DCDC Converters for Improved Light Load Efficiency and Peak Power Increase

The paper describes design and control of bi- directional interleaved GaN transistors-based DC-DC converter combined with a lower power single phase DCDC converter for supercapacitor energy storage integration into DC microgrid. The implementation of GaN transistors allows to increase switching frequency and reduce size of magnetic components thus decreasing size of converter, but at the same time the loss in discontinuous mode is high due to higher voltage drop into reverse conduction mode. In the paper it is proposed mutual control strategy of both converters to extend boundary operation region of interleaved converter thus avoiding current control loop in each phase. The paper describes proposed control method. Proposed algorithm has been implemented into Matlab Simulink simulation model. Simulation results shows that the discontinuous operation of the control method simulation, and conduction mode of the interleaved converter is avoided. The experimental results show measured efficiency of the converter working into boundary conduction mode in a range from 96 to 98.5 percent.