Research On Rare Earth Electrolysis Power Supply Based On PS-FB-ZVZCS

Recently, with the prices of RE(rare earth) accelerating, domestic relating departments and RE industry have put more emphasis on the extraction and electrolysis of the rare earth. Power source that is used to electrolyze has been put on the agenda.Since IGBT has the advantages of small volume, rapid response, short reverse time and low power dissipation, rare earth power employ the IGBT as its power switches, which solves the disadvantage of the large volume and high power dissipation of the silicon control rectifier of the traditional power. Moreover, with the higher switching frequency, this power optimizes the performance of the output.Through analysis and comparison of the Phase Shift- Full Bridge- Zero Voltage Zero Current Switching (PS-FB-ZVZCS) topology and the secondary rectifier circuit of high power source, this paper employ the PS-FB-ZVZCS topology. The primary inductor of its main circuit is in series with blocking capacitor and saturated inductor. The saturation inductor helps accelerate commuting and prevent the loss of duty ratio, while the blocking capacitor helps the reset of the primary current and prevent the high-frequency transformer from magnetic saturation.The model of the electrolysis power for rare earth and the analysis of the power dissipation of the IGBT, transform, diodes used to rectifier has been proposed in this paper. According to that, the accurate type and parameters of the main devices has been chosen. This paper has predicted the efficiency of this converter through computing the efficiency of one module and the results shows that the error between the computing efficiency and the experiment efficiency is less than 50W. Considering both the topology of the main circuit and different power dissipation of devices, the thermal circuit of the electrolysis power has beendesigned. This paper has analyzed the cause of the electro-magnetic-interference (EMI), and attenuated the EMI sources. Firstly, the saturation inductor of the transform has been optimized, which helps reduce the interference of the system and the magnetic devices. Besides, other EMI sources has been shielded or absorbed, which helps enhance the stability of the electrolysis power.An electrolysis power of 380V input, 0~15V and 0~15000A output has been designed. The waveform of the voltage and current of the leading-leg switches and the lag-leg switches verified that this system has achieved the soft switching in full range. The computing results and the experiments of the electrolysis power verified that its efficiency is larger than 81%.