多路数字绝缘电阻测试仪的设计

为了准确可靠地实现电气设备绝缘电阻多路巡回检测,提出了基于PC/104总线的数字绝缘电阻测试仪的结构和系统硬件、软件设计方案;系统选择反激式单片开关电源设计方案,产生250V直流测试电压;采用光电微电子继电器开关电路,检测24路绝缘电阻;采用线性隔离放大电路,提高系统安全性;实现了多路绝缘电阻的巡回检测和自动量程转换功能,绝缘故障时准确报警;实验结果表明,该仪表满足测量多路绝缘电阻的要求,缩短了测试时间,提高了测试效率,运行性能良好.

Design of Multi-Circuit Digital Insulation Resistance Measurement Instrument

In order to realize exact and dependable measurement of multi-circuit insulation resistance of electrical devices, the structure of digital insulation resistance instrument based on PC/104 is proposed, giving the design strategy of software and hardware. The scheme of flyback switching power supply on a single chip is adopted to provide 250V DC testing voltage. The relay switch circuit is applied to realize the measurement of 24-circuit insulation resistances. The linear insolated amplifying circuit is applied to improve security. The multicircuit measurement and automatic measuring range transformation are realized in this instrument. The alarms can be accurately given under insulation fault conditions. The experimental results demonstrate the requirement of multi-circuit measurement is satisfied and testing time is reduced. The system can perform efficiently, stably and reliably.