Distributed fiber optic temperature measurement system for power cables, factory in China

Why do power cables need temperature measurement

In power supply lines, cable joints are the weakest link in the safe operation of the power system. According to statistics, cable joint accidents account for a large proportion of cable accidents. The reason is that the 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 increases may occur, which not only may cause cable damage but also lead to large-scale power outages and even fire accidents.

After the cable is laid, in order to make it a continuous line, each section of the line must be connected as a whole through cable joints. However, due to the skin effect of charges, eddy current loss, and insulation medium loss, additional heat is generated, which causes the temperature of the cable to rise. When the load current of the cable is too large, the temperature of the cable joint will rise sharply, causing the core wire to heat up and causing a fire; De plus,, there are gaps at the cable joints, which can allow rainwater to seep in and cause the cable joints to become damp, leading to accidents.

At present, staff generally manually measure the temperature at the cable joint, which increases the workload of the staff, and cannot measure the temperature in real time, making it difficult to timely understand the situation in the event of an accident.
In summary, the existing technical problem is that the staff manually measures the temperature at the cable joint, which increases the workload of the staff and makes it difficult to timely understand the situation in the event of an accident; Lack of corresponding protective devices at cable joints can easily lead to accidents caused by moisture in cable joints.

In order to reduce intermediate joint failures, on the one hand, emphasis should be placed on improving the quality of cable products and on-site production processes, and on the other hand, monitoring and diagnosis should be strengthened. At present, the main monitoring methods for power cables include online monitoring of insulation resistance, online monitoring of partial discharge, online monitoring of DC component method, and online monitoring of temperature. Temperature, as a non electrical quantity, is an important parameter reflecting the operating status of cables. The occurrence of various faults in intermediate joints is not a sudden process. It is usually due to the continuous increase in temperature, insulation aging, increased contact thermal resistance, and increased leakage current before thermal breakdown occurs, which is a process from quantitative to qualitative change. By monitoring the temperature of the intermediate joint in real-time and analyzing historical data, the location of insulation defects can be determined, and the insulation condition of the intermediate joint can be grasped. De plus,, excessive current carrying capacity of power cables can cause the working temperature of the cable core to exceed the allowable value, resulting in a shortened insulation life of the cable compared to the expected value; If the current carrying capacity is too small, it will make the copper or aluminum materials of the wire core unable to be fully utilized. Therefore, the real-time measured temperature value can be used to calculate the temperature of the wire core conductor to achieve the purpose of load regulation and dynamic capacity increase.

Effective monitoring of the temperature of intermediate joints in power cables can determine local overheating points, assess insulation aging conditions, and timely detect safety hazards through real-time monitoring values and historical temperature values; En même temps, real-time monitoring values can also be used to calculate the temperature of the wire core conductor, which is of great significance for ensuring the reliability, stability, 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.

Le distributed fiber optic temperature measurement system for power cables can monitor the temperature of the cables online and accurately locate the heating fault points of the cables. Monitoring on-site safety and reliability, accurate measurement, and good stability; The temperature measurement accuracy reaches ± 1 ℃, is not affected by electromagnetic interference, and the sensor does not need to be calibrated for long-term use; Real time online, 24-hour monitoring, 24/7 on duty, eliminating human negligence; Strong scalability: The temperature measurement system can adopt single to multiple channels, which can be easily connected to the internal power network and support various communication protocols and specifications; Fast temperature measurement speed, using synchronous scanning and parallel detection technology, temperature data collection and transmission can be completed within seconds; Can achieve measurement of temperature rise rate, providing strong technical support for temperature monitoring; Remote transmission, with distances ranging from several kilometers to tens of kilometers, is easy to network.