Hệ thống đo nhiệt độ cáp quang phân tán cho cáp điện, factory in China-INNO

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. Theo thống kê, 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.

Sau khi đặt cáp, để biến nó thành một dòng liên tục, mỗi đoạn đường dây phải được nối tổng thể thông qua các mối nối cáp. Tuy nhiên, do hiệu ứng da của điện tích, tổn thất dòng điện xoáy, và tổn hao trung bình cách điện, nhiệt bổ sung được tạo ra, làm cho nhiệt độ của cáp tăng lên. Khi dòng tải của cáp quá lớn, nhiệt độ của mối nối cáp sẽ tăng mạnh, khiến dây lõi nóng lên và gây cháy; Ngoài ra, có những khoảng trống ở các mối nối cáp, có thể để nước mưa thấm vào làm ẩm các mối nối cáp, dẫn đến tai nạn.

Hiện tại, 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.
Tóm lại, 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, một mặt, 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. Hiện tại, 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. Nhiệt độ, 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, lão hóa cách nhiệt, 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. Ngoài ra, 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. Vì thế, 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; Đồng thời, 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, sự ổn định, 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.

các 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, đo lường chính xác, và ổn định tốt; Độ chính xác đo nhiệt độ đạt ± 1 oC, 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: các hệ thống đo nhiệt độ 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.