In High-power Soft-switching Converter

With a variety of electronic devices in people's daily lives and work, the demand of the power supply is increasing. The traditional AC / DC switching power supply makes the sinusoidal input current waveform of AC input converter electricity distorted and produces large amounts of harmonic currents, which cause the efficiency of power supply decreased and the harmonic pollution on the surrounding environment. And also there are low efficiency and low power density. This thesis studies the power factor correction technology and phase-shifted full bridge technology, which make high efficiency and power density at the high frequencies of soft-switching power supply raise the power factor and reduce harmonic pollution.For AC / DC converter, it was used single-phase Boost Power Factor Correction converter and the inductor current operates in continuous mode. With the loop controlled the average current mode and the auxiliary circuit added in the circuit, it achieves soft switching and efficiency to reach more than 90%. In this article, the operating principles and design process of the power factor correction converter circuit are described in details. Through the power factor correction, it inputs the current sinusoidal to low the harmonic components in the current.For DC / DC converters, it was used the Phase-shift full-bridge converter for the high power occasions and achieve zero-voltage switching through the converter leakage inductance and the primary series resonant inductor to the power control of the parasitic diode / capacitor. Through soft switching, efficiency of converter reach more than 90%. In the article, the operating principle and design process of the Phase-shift full-bridge converter are described in details. With the loop in the circuit feedback, it uses peak current mode control and make the slope compensation at the duty cycle which is greater than 0.5.Compared with the conventional power factor correction converter and full bridge converter, the power factor and efficiency of the converter are improved, the voltage stress and current stress of the switch are reduced, the du/dt, di/dt and the electromagnetic interference are decreased.Finally, the samples are provided. The results are shown the circuit stability and the performance indicators at the standard of the design requirement.