36kV电子束轰击炉高压直流开关电源设计

Design of High-Voltage DC Switching Power Supply for 36kV Electron Beam Bombarding Furnace

针对高压直流开关电源变压器绝缘易被击穿和输入并联输出串联电源拓扑输出电压纹波大、精度低的问题,提出了改变变压器绕组布局结构的分段式绕制方法和一种数字化错相控制策略。首先,详细给出了分段式变压器的绕制结构和设计方法;其次,基于所建立的占空比与输出电压的数学模型,给出了错相控制策略中最小纹波因数下的占空比设计原则,并对纹波因数进行了定量分析;最后,绕制了分段式高频高压变压器样品,研制了36kV/10A电子束轰击炉电源的样机。实验结果表明:变压器分段式绕制方法降低了副边绕组的层间电场强度,进而可降低变压器绝缘等级,防止变压器绝缘击穿;所提出的错相控制策略可把输出电压纹波由23.2%降低到3.5%。总体来说,所提出的方法和策略提高了36kV电子束轰击炉高压直流开关电源的功率密度和稳定性。

A segmented winding method for changing winding structure of high-frequency high-voltage transformer and a digital phase-interleave control scheme are proposed to solve the problems of easy transformer insulation breakdown,and larger ripple and lower precision of output voltage in input-parallel output-series topology for high-voltage DC switching power supply.The winding structure and design method of segmented transformer are introduced in detail,the design principle of duty circle is then put forward with minimum ripple factor in the phase-interleave control scheme following the established mathematical model of duty circle and output voltage,and the ripple factor is quantificationally analyzed.A high-frequency high-voltage transformer sample is constructed,and a 36 kV/10 A high-voltage DC switching power supply prototype for electron beam bombarding furnace is developed.Simulation for electric field distribution of the high-voltage transformer on the finite element analysis software shows that the segmented winding method decreases interlayer electric field intensity of secondary winding to lower the insulation level for the transformer,and insulation breakdown can be prevented.Experiment of the high-voltage DC switching power supply indicates that the proposed phase interleave control scheme lowers the output voltage ripple from 23.2% to 3.5%.As a whole,the proposed method and scheme improve the power density and stability of the high-voltage DC switching power supply for 36 kV electron beam bombarding furnace.