Soft-switching Of High Power Factor Ac / Dc And Soft-switching Dc / Dc Conversion Technology Research

In this paper, we design a power converter module which consists of soft-switching high power factor circuit and soft-switching Full-Bridge PWM DC/DC circuit with secondary active clamp switch. The parallel current sharing technique is used in the design of the high power switching power supply. The paper analyses the power converter modul's principle of operation, key techniques and solutions emphatically. We design circuit parameters and developed a prototype. The main contents of the paper are as follows: 1 .We study Boost ZVT PWM convert circuit and design soft-switching high power factor AC/DC converter using this circuit. The converter programs the input current waveform of the converter to follow sine wave of the input voltage and achieves power factor of O.99.Boost ZVT PWM circuit makes this converter achieve zero voltage turn-on of the main switch and zero current turn-off of the boost diode. Current and/or voltage stress of the components are reduced by Soft-switching, System EMI is also reduced. 2.We investigate soft-switching Full-Bridge PWM DC/DC converter with secondary active clamp switch and design the control circuit of the secondary active clamp switch. The converter can achieve ZVS for leading-switches and ZCS for lagging switches. The converter has many advantages such as the low stress of the components, no duty-cycle loss, no lossy snubber parts, no saturable reactor, simple circuit topology and high efficiency, which makes the converter attractive for high-voltage and high applications. 3.We discuss the principles and modes of current sharing control and design current-sharing circuit. 4.We develop a 2Kw power converter module prototype.