The Research Of450kW High Voltage Power Supply Of Electron Beam Melting Furnace

Electron Beam Melting Furnace is the device which in the vacuum environment without air, the kinetic energy of the electron bean flow with high speed is converted into heat energy as the heat source to melt the highly flexible and refractory metal, referred to as "EB furnace". It is mainly composed of high voltage DC power supply and control system, the electron gun, and the vacuum furnace system.Electron Beam Melting Furnace high voltage DC power system is an important part of the Electron Beam Melting Furnace equipment, and the quality of the high voltage power supply performance directly determines the stability of the melting furnace system. The traditional high voltage power supply of Electron Beam Melting Furnace is mainly frequency boost power supply controlled by thyristor. Not only the size of the transformer and output filter is huge but also the power supply ripple is large, efficiency is low. These problems seriously affect the life of cold cathode electron gun and the quality of melting. For the technical shortcomings of the traditional frequency high voltage DC power supply, this research will apply the LCC resonant converter to the high voltage DC power supply. This application not only improves the switching frequency, reduces the volume of transformer and filter, but also realizes the soft switching, reduces the switching losses.A variety of boost converter topologies were studied in paper, to determine the full bridge converter power system solution. The input of the high voltage DC power supply is the three-phrase380V frequency AC Power, the first stage is the controlled thyristor rectifier, the later stage is the LCC resonant converter, the output voltage up to-30kV, rated output power up to450kW. Though comparing the characteristics of the series resonant, parallel resonant,the series and parallel resonant, finally, the paper choose the LCC series and parallel resonant, realizes the soft switching of IGBT.DCM1mode of the LCC resonant converter can realize the zero-current switching of the IGBT. The frequency control of the LCC series and parallel resonant was studied in this paper, and detailed theoretical analysis and parameters design process was given in the paper. The design of the high-frequency and high-voltage transformer was given in the paper. The high voltage DC power supply, the design is verified to be correct.