低压断路器触头温度传感器技术研究

Research on Contact Temperature Sensor Technology of Low Voltage Circuit Breaker

低压断路器通断时,其触头会产生接触电阻,当电流流过触头时会发热,这种情况会对触头造成损耗,进而影响断路器的正常工作。利用具有负阻态特性的MF51半导体热敏电阻,对触头的温度传感器进行了研究。通过MATLAB软件对MF51的负阻态特性曲线进行了分段线性化,并获得了线性表达式。再通过Multisim搭建了传感器的硬件电路,仿真所得的数据符合MF51热敏电阻的特性。通过测得的热敏电阻的电阻值,再结合曲线拟合后的电阻-温度线性关系式,很容易得到低压断路器的触头温度。通过触头的温度情况,可以对低压断路器工作状态进行判断和动作,确保用电的安全。

When the low-voltage circuit breaker is turned on and off,its contact will generate contact resistance,which will generate heat when the current flows through the contact.This will cause loss to the contact,which will affect the normal operation of the circuit breaker.The temperature sensor of the contact was studied by using the MF51 semiconductor thermistor with negative resistance characteristics.The negative resistance characteristic curve of MF51 was linearized by MATLAB software,and a linear expression was obtained.The hardw-are circuit of the sensor is built by Multisim,and the data obtained by the simulation conforms to the characteristics of the MF51 thermistor.The contact temperature of the low-voltage circuit breaker is easily obtained by measuring the resistance value of the thermistor and the resistance-temperature linear relationship after the curve fitting.Through the temperature condition of the contact,the working state of the low-voltage circuit breaker can be judged and acted to ensure the safety of power consumption.