碳化硅二极管在高压电源的应用研究

Research and application of silicon carbide diode in high voltage power supply

依据脉冲调制器高压电源的需要,研制基于平面绝缘芯变压器结构的高压充电电源。高压充电电源输出结构由多组输出线圈串联,所以电源输出整流二极管数量多,而二极管的功率损耗对电源密封输出结构的温升有直接的影响,所以分别对普通二极管、快恢复二极管和碳化硅肖特基二极管的工作特性进行仿真分析,分析了二极管的关断电流斜率和反向恢复峰值电流的关系,比较了三种二极管在电路中的功率损耗,并依此确定了应用于高压低电流电源上选择二极管的原则。选择C4D05120E(1200V9A)作为高压电源的整流二极管,设计了高压整流电路,并在实验中验证了二极管功率损耗,整体的功率损耗符合二极管功率特性的分析。

[Background] High voltage charging power supply is developed from the requirement of pulse modulation high voltage power supply. The power supply structure consists of a planar insulated core transformer in series with multiple output coils. Therefore, many rectifier diodes are used accordingly. Critical power loss of rectifier diodes has direct influence on the temperature rise of sealed output structure of power supply.[Purpose] This study aims to reduce the influence of diode power loss according to the operating characteristics of the diode and determine the selection principle of the diode.[Methods] Based on the relationship between the current turn-off slope and reverse recovery peak current of various diodes, circuit simulation and parametric analysis of common diodes, fast recovery diodes and silicon carbide Schottky diodes were carried out, silicon carbide diodes C4D05120E (1 200 V 9 A) was selected as high-voltage rectifier diode to design high voltage rectifier circuit.[Results] The high voltage power supply operates at 70% load, and the temperature rise caused by the loss of power of silicon carbide diode is within 2°.[Conclusion] The application of silicon carbide diode improves the power loss of high voltage power rectifier diodes. With the increase of switching frequency of high voltage power supply, the advantages of silicon carbide diode will be more obvious.high voltage power supply, the advantages of silicon carbide diode will be more obvious.