大功率半导体激光泵浦固体激光器脉冲电源设计

Design of pulse power supply for diode pumped solid state laser

介绍一种大功率半导体激光泵浦固体激光器(DPSSL)脉冲驱动电源的设计电路及其控制方法。根据半导体激光器的工作特性,采用前级电容充电电路与后级脉冲电流产生电路相结合的电路结构。由于LCC谐振电路具有软开关特性和抗负载短路、开路的能力,又能够实现对储能电容恒流充电的功能,因此其适合做为脉冲电源中储能电容的充电电路;后级脉冲电流产生电路选择大功率MOSFET做为主控器件,利用MOSFET饱和区的漏极电流可控性,通过栅极电压控制产生负载脉冲电流。控制部分采用模拟与数字相结合的控制方式,使脉冲电源控制更加灵活,引入脉冲电流指令给定积分器,可以更有效地控制脉冲电流上升过程,抑制电流过冲,提高控制精度,使脉冲驱动电源产生类似矩形波的大功率脉冲电流。搭建了脉冲功率为28kW的实验平台,实验达到的指标:脉冲电流幅值80A,脉冲电压350V,脉冲宽度100μs,重复频率100Hz。

This article mainly introduces a design circuit and control method for a pulse power supply of diode pumped solid state laser（DPSSL）. According to the operating characteristics of the semiconductor laser, a circuit structure in which a front-stage capacitor charging circuit and a post-pulse current generating circuit are combined is used. Because the LCC resonant circuit has the characteristics of soft switching and resistance to load short-circuit and open-circuit, it can also realize the function of constant-current charging of the energy storage capacitor. Therefore, it is suitable for the charging circuit of the energy storage capacitor in the pulse power supply; the latter-stage pulse current generating circuit selects a high-power MOSFET as a master control device, utilizes the drain current controllability of the saturation region of the MOSFET, and generates a pulse current through the gate voltage control. The control part adopts a combination of analog and digital control methods to make the pulse power supply control more flexible, and add a given integrator in the pulse current given step, which can effectively control the pulse current rising process, suppress the current overshoot, improve the control accuracy, and make the pulse drive power supply generate a pulse current similar to a rectangular wave. An experimental platform with a pulse power of 28 kW was set up. The experimental parameters were： pulse current amplitude of 80 A, pulse voltage of 350 V, pulse width of 100 μs, and repetition frequency of 100 Hz.