Research On Linked Full Bridge Soft-Commutation DC/DC Power Converter With Secondary-Shifted Pwm Rectifier Switches

The rapid development of power electronics is regarded as the second electronic revolution in the human society. Switch power supply is involved in power electronics, intelligent IC, new circuit technology and other technical fields, in which the technology of soft-switching power electronic transformation is a hot subject in recent years.This thesis details the development process of soft switch and hard switching power circuit faults were explained, then put forward with soft switch to replace a hard switching development direction. Full bridge Phase-Shifted PWM converter adopts Phase-Shifted control, because of the simple control, it is widely applied. Along with the development of soft switch technology, switches of the full bridge phase-shifted PWM converters can realize "softening", so as to reduce the wastage of switches and the stress of voltage and current. Phase-shifted soft-commutation ZVS PWM full bridge DC/DC converter is a research hotspot of the converters. Such as high performance, high efficiency, low noise, low pollution and the theoretical issues are needed considered. This thesis based on the circuit structure, control principle and switch mode of phase-shifted soft-commutation ZVS PWM full bridge DC/DC converter, point out the insufficiency. In order to solve these problems, the fundamental phase-shifted on the transformer primary said ZVS PWM DC/DC converter is made corresponding improvement, through the strict theoretical derivation, presents a phase-shifted on the transformer secondary said ZVS PWM DC/DC converter, this DC/DC converter can achieve ZVS transition commutation in the primary said and ZCS in the secondary said, which can operate under wide load variations from a light load to a heavy load as well as a condition of PWM voltage regulation strategy. Compared with the fundamental phase-shifted on the transformer primary said ZVS PWM DC/DC converter, the phase-shifted on the transformer secondary said PWM DC/DC converter can reduce the circulating flowing through the transformer primary winding and primary-said devices and circuit components during the phase shifted interval time and then reduce the loss of the working switches.This thesis introduces converter structure design and working principle. Simulation and experimental results demonstrate the validity of the theoretical analysis.