A new single switch ZVS forward converter with a wide soft-switching range is proposed here. Compared to the conventional forward converter, the proposed converter uses fewer components and operates under ZVS soft switching. A capacitor, along with both the leakage and magnetizing inductances, provides ZVS soft switching and transformer core reset. To regulate the output voltage against the input voltage and the load variations, an inductor is added to the converter. The inductance of the additional inductor varies with the direct current (DC) of the DC bias winding to regulate the output voltage. Therefore, the duty cycle and the switching frequency are constant in the proposed converter. With the constant duty cycle and the constant switching frequency, the wide ZVS soft switching is achieved. The proposed converter is completely analysed theoretically. The finite element analysis is used to design the additional inductor. By designing an experimental prototype, the theoretical analysis is justified using the experimental results.

SiCMOSFETs are widely employed in power converters due to their high switching speed and low switching loss. However, their low current rating due to the limited active area restricts their high power applications. To apply SiC MOSFETs in high power applications, providing parallel connection is an inevitable choice. To tackle the challenge of imbalanced current sharing problem between parallel SiC MOSFETs, a new passive compensator based on planar transformer (PT) is proposed here. Compared with the conventional transformer compensators, parasitic elements are adjustable and predictable in PT compensators, which is especially important for mass production aims. After explaining the concept of the physical operation of the PT compensator, the whole parasitic elements of the PT compensator are formulated. Based on estimated parasitic elements and using the finite element method (FEM), an optimum PT structure is extracted for imbalances in current sharing of parallel SiC MOSFETs. Afterward, the PT design is discussed in detail and then, a boost converter is constructed. Finally, the experimental results are presented to verify the reliability, accuracy, and effectiveness of the theoretical results.