How to Monitor High Voltage Cable Temperature, Complete Guide, Top 10 Excellent Manufacturers in 2025

Fiberoptisk temperatursensor, Intelligent overvågningssystem, Distribueret fiberoptisk producent i Kina

Power cables are cables used for transmitting and distributing electrical energy in power systems. Compared with overhead power lines, power cable power supply has the advantages of high transmission reliability, small insulation distance between lines, less land occupation, no ground space occupation, strong confidentiality, and easy to significantly improve power supply capacity. Derfor, with the development of urbanization and urban power grids, power cables have been widely used. Dog, in the process of use, power cables also have disadvantages such as high cost, difficulty in fault detection and maintenance, high process requirements for power cable accessories (intermediate joints, terminal joints, osv.), and on-site construction operations requiring workers to have high operational skills. With the increase in the number of cables used and the improvement of transmission capacity, the operational reliability of power cables is increasingly valued due to the serious harm caused by faults.

Fluorescent fiber optic temperature measurement device for cable joints

Effective monitoring of the temperature of intermediate joints in power cables can determine local hotspots, assess insulation aging conditions, and promptly identify safety hazards through real-time monitoring values and historical temperature values; Samtidig, real-time monitoring values can also be used to calculate the temperature of the core conductor, which is of great significance for ensuring the reliability, stabilitet, and economy of the power system by reasonably utilizing the capacity of power cables to regulate loads and dynamically increase capacity within the allowable range. In the power supply line, the intermediate joint of the cable is the weakest link in the safe operation of the power system. According to statistics, cable joint accidents account for 90% of cable accidents. The reason is that cable joints have problems such as poor contact, loose compression joints, and damaged insulation strength. In environments with increased electrical load or hot weather, abnormal temperature rise may occur, which not only leads to cable damage but also inevitably causes widespread power outages and even fire accidents.

Distributed Fiber Optic High Voltage Cable Temperature Measurement System

The basic working principle of fiber optic sensors

Fiber optic sensors send optical signals from a light source through optical fibers into a modulator, where the measured parameters interact with the light entering the modulation region, causing changes in the optical properties of the light (such as intensity, wavelength, frequency, phase, polarization state, osv.) and becoming the modulated signal source. After being sent through optical fibers into a photodetector and demodulated, the measured parameters are obtained. In the power system, it is necessary to measure parameters such as temperature and current, such as temperature detection inside the stator and rotor of high-voltage transformers and large motors. Due to the susceptibility of electrical sensors to electromagnetic interference, they cannot be used in such situations and can only use fiber optic sensors.

Characteristics of distributed fiber optic temperature sensing device

Den Distribueret fiberoptisk temperaturfølersystem not only has the advantages of universal fiber optic sensors, but also has the ability to sense the temperature distribution of various points along the fiber optic line. With this feature, we can continuously measure the temperature of various points along the fiber optic line in real time, with a positioning accuracy of meters and a measurement accuracy of 1 grad. It is very suitable for large-scale intersection temperature measurement applications. In current market applications, most of them are pre installed in fixed positions on the ground through pre embedding, which is not convenient for flexible movement, and to some extent requires a large quantity through pre embedding, undoubtedly increasing investment costs. The use of distributed fiber optic temperature measurement principle to monitor the temperature of cable bodies and tunnels is one of the important means to improve the operation and management level of cables and channels, especially widely used in ultra-high voltage cable lines. Nu, State Grid Corporation of China stipulates that cable distributed fiber optic temperature measurement systems must be installed in cable channels above level two.