Design Of High Voltage And High Power AC-DC Power Supply Based On ZVS Phase-Shifted Full-bridge

Energy is the lifeblood of a country’s economic development. China’s economy has developed rapidly since the reform and opening up, the problem that comes along is the huge energy consumption. At present, the main mining area of shallow resources exploitation potential has reached the limit. As a consequence, deep mineral exploration can effectively alleviate the plight of decreasing mineral resources in our country.Controlled Source Audio-frequency Magnetotelluric is one of geophysical methods which could explore mineral in deep. It uses artificial emission source and electrical source emission system to transmit pulse current to earth as a load. The earth generates excitation signal, which can be received by receiving system, then using inversion analysis to achieve mineral resources exploration. The study of the electrical transmission system has already a certain achievement both in China and abroad, but the field of commercial electrical source emission system abroad ahead a lot of the level in China. By comparing the domestic and overseas outstanding research results, combining with its advantages and disadvantages, this paper studies the AC-DC power supply HPT45-IV transmit system, based on the existing technology in the laboratory.Soft-switch technology is a hot spot in the development of power electronics technology in recent years. Using soft-switch technology can reduce not only the switching loss of AC-DC power, but also the volume of magnetic components due to the increase of the switching frequency, consequently the overall weight of the power supply is lightened so that it can be used conveniently in the field. This paper analyzed the main soft-switch topology, the phase shifted full bridge soft switching topology works well in the high power circuit is selected finally, by analyzing the working mode of phase-shift full-bridge soft-switch topology at different times, the changing trend of voltage and current in the circuit and the principle of soft-switch process. To solve the problem that it is difficult for the traditional phase-shifted full-bridge soft-switch topology to realize the soft switching of the lagging arm in the condition of light load, a modified phase-shifted full-bridge soft-switch topology is proposed and analyzed.This paper is also aimed at the problem of peak voltage of secondary side rectifier in the full-bridge topology, introduces the operation mode of the full-bridge circuit at all times in detail, analyzes the changes of voltage and current in the circuit, describes the principle of the voltage spike caused by the reverse recovery characteristic of the rectifier tube and the parasitic parameters of the main components. Usually it caused a large loss in the high frequency and reduced the power supply efficiency to use the way of adding RC network to suppress the voltage spike. On account of the reason of the voltage spike, an auxiliary circuit adding the passive components to suppress the peak voltage of the rectifier tube is proposed in this paper. Moreover, due to the high frequency transformer and inductor are important components of AC-DC power supply,the design of high frequency transformer and inductor is introduced in detail according to the output index of power supply, the calculation process of the main parameters in the design process is given in this paper. After the completion, the output performance of AC-DC power supply reaches the expected index. The power supply can work stably in soft switch state and meet the voltage spike suppression requirements.