Soft-switching is a technique that makes use of capacitor, inductor, and other components to realize resonance, for reducing the switching losses of switching components and EMI in the power electronic converter. As a result of adding resonant components such as capacitor or inductor into the soft-switching converter, it is certain that the soft-switching converter will have more current paths than the hard-switching converter. Consequently, the sneak circuit phenomena in the soft-switching converter will be more complex than those in the hard-switching converter.
According to the development of the soft-switching technique, the soft-switching converter can be divided into three types, including the quasi-resonant converter, the zero-switching pulse-width modulation (PWM) converter, and the zero-transition PWM converter. In this chapter, the sneak circuit phenomena of several typical soft-switching converters will be introduced.
4.2 Sneak Circuits of Full-Bridge ZVS PWM Converter
Among the DC/DC converters, the Full-bridge (FB) PWM converter is generally used in high-power applications, and the phase-shift technique is often used to control an FB converter, which can make the converter operate in zero voltage switching (ZVS). The basic soft-switching principle of the FB PWM converter is that ZVS of all switching devices can be achieved by the resonance between the leakage inductor of the transformer or ...