基于温度梯度法电缆接头温升在线监测装置的设计

Design of On-Line Monitoring Device for Temperature Rise of Cable Joint Based on Temperature Gradient Method

电缆井内电缆中间接头过热到事故发生，其发展速度缓慢、且时间较长，目前主要依靠人工红外巡检方法检测电缆中间接头连接处温度是否异常，这种巡检存在的主要问题是可靠性低、实时性差，难以及时发现设备安全隐患，为了有效地进行电缆中间接头温度的自动监测，本文提出并设计了一种基于温度梯度法，并利用热敏电阻结合振荡电路和CT供电设计了实时在线监测装置，实现对电缆中间接头应力集中点、中间连接点和环境温度的直接测量，经对比试验表明，本装置测量精度可达±2℃，可以满足电缆井电缆中间接头温升在线监测的要求，对及时发现温升故障，提高检修效率，减轻人力、物力和财力具有非常重要的意义。

In the cable well, from overheat of the cable intermediate joint to the accident, the development speed is slow and the time is long. At present, the inspection of the temperature at the cable intermediate joint is mainly based on the artificial infrared inspection method which has the characteristics of low reliability and poor real-time performance, so it is difficult to detect the hidden danger of the equipment in time. In order to effectively monitor the temperature at the cable intermediate joint, this paper presented and designed a method based on temperature gradient, and combined thermistor with oscillating circuit and CT power supply for real-time online monitoring device. It realized the direct measurement of the stress concentration point, the intermediate connection point and the ambient temperature of the cable intermediate joint. The experiment results illustrated that the measurement accuracy can reach ±2℃ , which can meet online temperature monitoring requirements for the cable joint in the cable wells, and it is imperative for detecting temperature fault, improving maintenance efficiency and reducing manpower, material and financial resources.