一种用于恒流充电电源的保护系统的研制

Development of Protection System for Constant-current Power Supply

在大功率恒流充电电源给高压脉冲电容器充电时,由于高压电容的放电回路电流是一个几十kA的振荡电流,该电流反馈到充电电源会导致充电系统损坏。为解决此问题,研制了一个保护系统,该系统由大、小电感和高压硅堆等组成,结构简单,能够有效隔离大电流反馈到充电电源。介绍了该保护系统的保护原理后设计了其结构、材料和尺寸,并推导了空芯螺线管电感值的计算公式;用ANSYS软件对空芯螺线管和实际制作的电感的磁力线分布进行了模拟,算出其磁阻,从而得到了实际电感的理论计算值,该计算值与RLC精密仪器测得的电感值很接近,从而验证了该计算公式的正确性。用Pspice软件对系统的保护效果进行模拟计算的结果表明,该保护电路的存在对主放电回路几乎没有影响;当反向脉冲电流过大时,首先损坏的是反向保护硅堆,从而保护了恒流充电电源。

High repetition is a very important development trend for high current electron beam accelerators. In the high repetition accelerator based on capacitive energy store, the constant-voltage power supply has some difficulty in charging the capacitor up to demanded high voltage in short time, so the constant-current power supply is required, which can charge the capacitor quickly and efficiently. However, after the high voltage pulse capacitor is charged by the large power constant current power supply, a reversal current is created by the inductance of the load in the dis- charge circuit. The current feeds back to the constant current power supply, and can make damage to the power supply system. Consequently, a protection system with the silicon stack of high voltage and two inductors that stand up to 50kV is investigated. Based on the electromagnetic equations, the formulas for calculating the inductances of the protection system were deduced. The magnetic inductance line distribution of the air core solenoid is carried out by the ANSYS. The theoretical values of the inductances well agree with the values measured by RLC precision in- strument. In addition, with the main parameters of the protection system the discharge circuit is obtained and simu- lated by the Pspice software. The results show that the protection system has less effect on the main discharge cir- cuit and when the reverse pulse current is excessively large, the reverse protection silicon reactor will be damaged firstly, so the constant-current power supply can be protected. The theoretical and simulated results well agree with the experimental results. The designed protection system is employed to protect the constant-current power supply in high current electron beam accelerator, and is featured by its compactness and reliability.