Soft Commutated DC-DC Converter Using Coupled Output Inductor

This paper presents a new Soft Commutated DC-DC converter with coupled output inductor. In addition zero-voltage and zero-current-switching (ZVZCS) is achieved when switches turn on and turn off during non conduction of the transformer or when there is no voltage or current across the switches which proves that the switching losses can be reduced and the efficiency can be increased by using coupled output inductor. The proposed full-bridge converter can be operated by using Pulse Width Modulation. In order to ensure the soft commutation of the diode in the auxiliary circuit, the leakage inductance of the coupled output inductor is used. The proposed converter also employs the phase-shift control.

By employing a simple auxiliary circuit with neither lossy components nor active switches, soft-switching of the primary switches is achieved. The proposed converter has many advantages such as simple auxiliary circuit, high efficiency, low voltage stress of the rectifier diode and self-adjustment of the circulating current, which make the proposed converter attractive for the high voltage and high power applications. The detailed design and operating principles are analyzed and described. The Pspice simulation results are verified with the experimental results.