高精度程控直流电流源的设计与实现

Design and Implementation of High Precision Programmable DC Current Source

设计了一款高精度、低纹波、稳定性高的程控直流电流源,它采用STM3 2 F103微控制芯片作为整机的控制核心,设计上位机软件来实现对硬件系统的调控。硬件系统由双闭环结构组成,内环是由PI控制器构成电压串联负反馈,提高了输出电流的稳定性。外环则是通过A/D采样电路将实际电流值送入主控芯片,再根据相应控制算法重新调整D/A的输出,提高了输出电流的精度。测试结果表明,电流源的输出电流稳定度高达0.003%,精度达0. 01%,最大输出电流高达25 A,适用于电力部门、计量院等对电源精度要求高的场合。

A high precision,low ripple and high stability program controlled DC current source is designed.It uses STM32F103 micro control chip as the core of the whole machine,and the PC software is designed to control the hardware system.The hardware system consists of a double closed loop structure,and the inner loop is a voltage series negative feedback composed of PI controllers,which improves the stability of the output current.The outer loop sends the actual current value to the main chip through the A/D sampling circuit,and then adjusts the output of the D/A according to the corresponding control algorithm,which improves the accuracy of the output current.The test results show that the output current stability of the current source is up to 0.003%,the accuracy is up to 0.01%,and the maximum output current is as high as 25 A.It is suitable for power departments,metrology institutes and other places where high accuracy of power supply is required.