基于PID控制的Buck型开关电源研究

Research on Buck Switching Power Supply Based on PID Control

针对小功率开关电源在输入电压存在波动和负载变化情况下输出电压和功率不稳定的情况。以输入电压在15V~20V波动情况时,且负载的最大电流为5A,理论计算电感值和电容值,采用PID控制器使得输出电压稳定在5V。根据工程要求在MATLAB Simlink中建立仿真模型,仿真结果表明该Buck型开关电源采用PID控制器,开关频率设置为200kHz,电感电流纹波率为0.4,电压纹波在1%之内。该电路电压输出的纹波和相应速度满足工作需求。

The output voltage and power of small power switching power supply are unstable when the input voltage fluctuates and the load changes.In this paper,when the input voltage fluctuates from 15V to 20V,the maximum current of the load is 5A.The inductance and capacitance are calculated according to the relevant theory.The output voltage is stabilized at 5V by PID controller.According to the engineering requirements,the simulation model is established in MATLAB SIMLINK.The simulation results show that the buck switching power supply adopts PID controller,the switching frequency is set to 200kHz,the inductance current ripple rate is 0.4,and the voltage ripple is within 1%.The output voltage ripple and corresponding speed of the circuit meet the working requirements.