矿用多功能热电阻型隔离安全栅设计

Design of mine-used multifunctional thermal resistance type isolation safety barrier

针对常见热电阻型隔离安全栅存在的抗干扰性差、集成度低、功能单一等问题,设计了一种矿用多功能热电阻型隔离安全栅。该安全栅利用带有2路互相隔离输出的DC/DC隔离电源模块分别为安全侧和危险侧电路供电,结合信号的光耦隔离实现供电侧、危险侧和安全侧的三端隔离,具有热电阻二次非线性误差修正、热电阻传感器断线故障报警、带迟滞的高温报警及电压电流信号输出转换等功能。样机测试结果表明:2路热电阻可同时工作,阈值比较电路动作稳定;随着输入温度升高,输出电流基本呈线性增加,线性度高达0.15%,对应模拟量输出传输处理误差低于0.5%,符合相关规定要求;有效抑制了尖峰脉冲及各种噪声的干扰,具有较好的抗干扰性;最大相对误差仅为0.667%,低于同类型的XX6071型安全栅。实际应用结果验证了该安全栅温度测量结果准确,高温报警动作稳定,满足矿用电气设备的实际应用需求。

In view of problems of poor anti-interference performance,low integration and single function of common thermal resistance type isolation safety barriers,a mine multifunctional thermal resistance type isolation safety barrier was designed.The safety barrier uses DC/DC isolated power supply module with two mutually isolated outputs to supply power to safety side and dangerous side circuits respectively,and realizes three-terminal isolation of power supply side,dangerous side and safety side combining with signal optocoupler isolation.It has functions of quadratic nonlinear error correction for thermal resistance,thermal resistance sensor disconnection fault alarm,high temperature alarm with hysteresis,voltage and current signal output conversion and so on.The prototype test results show that:two thermal resistances can work at the same time,and the threshold comparison circuit operates steadily;with the input temperature increases,the output current basically increases linearly,the linearity is as high as 0.15%,and the corresponding analog output transmission processing error is less than 0.5%,which meets requirements of relevant regulations;it effectively suppresses the interference of spikes and various noise,and has good anti-interference performance;the maximum relative error is only 0.667%,which is lower than the similar type of XX6071 safety barrier.The actual application results verify that the temperature measurement results of the safety barrier are accurate and the high temperature alarm action is stable,which meets the actual application needs of mine electrical equipment.