Abstract: In order to test the insulation resistance of the high-voltage system of pure electric vehicles, this paper adopts the insulation resistance detection scheme based on the electric bridge method, uses AVR MCU as the control chip of the detection system, and adds LCD display, audible and visual alarm, serial communication and other modules. During the test, when the power supply voltage is 300 V, 500 V and 700 V respectively, keep the collected partial voltage resistance value as 20 kΩ, change the resistance value of the sliding rheostat in the test system, realize the collection of the insulation resistance network voltage, and send the data to the single chip microcomputer. After calculation, the insulation resistance value is obtained and displayed. When the insulation resistance does not meet the national standard, the buzzer alarm is triggered to achieve the warning effect. The simulation results show that the system works normally and meets the design requirements.

Key words: Pure electric vehicle; AVR microcontroller; Insulation resistance; Simulation test; System design

摘要： 为了对纯电动汽车高压系统绝缘电阻进行检测，文章采用基于电桥法的绝缘电阻检测 方案，使用 AVR 单片机作为检测系统控制芯片，外加 LCD 显示、声光报警、串口通信等模 块。测试过程中，在电源电压分别为 300 V、500 V、700 V 的情况下，保持采集的分压电阻 阻值为 20 kΩ，改变测试系统中滑动变阻器的阻值，实现对绝缘电阻网络电压的采集，并将 数据送到单片机中，经过计算得到绝缘电阻阻值并显示。当绝缘电阻不符合国家标准时，触 发蜂鸣器报警，达到警示效果。仿真结果表明，系统工作正常，且满足设计要求。

关键词: 纯电动汽车；AVR 单片机；绝缘电阻；仿真检测；系统设计