基于PIC单片机的Buck可调稳压电源设计

Design of Buck adjustable regulated power supply based on PIC microcomputer

为了满足教学实验中对开放式可定制电源的需求,以PIC单片机为监控中心,设计了一种集PID控制、电压监测、温度监控于一体的Buck电路可调稳压电源。将Buck电路的开关管移到下支路,以简化驱动电路;采用运放电路进行电压采样变换,提高了反馈信号的抗干扰能力;为了提高电压稳态控制精度,设计了两种改进策略,即输出电压均值滤波及PID控制量尺度变换。仿真及实验结果表明,在输入电压、负载较大变化时,均能快速稳定在预设值上,且具有较高的稳态精度。

In order to meet the demand of open customizable power supply in teaching experiment,a Buck circuit regulated power supply with PID control,voltage monitoring and temperature monitoring is designed with PIC MCU as the monitoring center.In order to simplify the driving circuit,the switch of Buck circuit is moved to the lower branch,and the anti-interference ability of the feedback signal is improved by using the op-amp circuit to sample and transform the voltage.In order to improve the accuracy of voltage steady-state control,two improved strategies are designed,namely,output voltage mean filter and PID control scale conversion.The results of simulation and experiment show that when the input voltage and load change greatly,they can quickly stabilize on the preset value and have high steady-state accuracy.