An Improved Interleaved DC-DC SEPIC Converter Based on SiC-Cascade Power Devices for Renewable Energy Applications

摘要

The worldwide development of renewable energy applications, especially those using solar photovoltaic (PV) panels and fuel cells, poses increasing requirements for improving power density, energy efficiency, and reliability of DC-DC power converters as they play a vital role in power conversion systems. Wide bandgap (WBG) semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN), contain superior material properties to replace conventional silicon (Si) materials, pushing the boundaries of power devices to handle higher power levels, blocking voltages, switching frequencies, and operating temperatures. This paper presents an improved interleaved DC-DC single-ended primary-inductor converter (SEPIC) based on a new hybrid SiC-JFET-cascode switch/SiC-Schottky diode for renewable energy applications. To evaluate the effects of SiC power devices on the switching behavior, total power loss, and efficiency of the converter, both Si-based and SiC-based converters are designed and compared under harsh operating conditions. The switching behavior of the Si and SiC power devices is analyzed through the double-pulse test (DPT), taking different switch currents and gate resistance values into consideration. The total power loss and energy efficiency of the two converters are calculated and compared over a wide range of switching frequencies and input voltages. The results reveal that the hybrid SiC-JFET-cascode switch/SiC-Schottky diode substantially improved the converter performance at a variety of operating conditions.