How to measure temperature at cable joints

Fiber optic temperature sensor, Intelligent monitoring system, Distributed fiber optic manufacturer in China

Fiber optic temperature measurement solutions include fiber optic temperature measurement for power cables, such as cable trench fiber optic temperature measurement and transformer fiber optic temperature measurement. The temperature range of cable joints, cable temperature standards, and cable temperature measurement systems are all of great concern to everyone.

The Importance of Cable Joint Temperature Monitoring System

The causes of multiple high-voltage cable fire accidents in China are mostly due to poor cable joints, resulting in increased contact resistance, which in turn causes the temperature of the joints to rise, leading to even worse joint contact. Without monitoring it, it forms a vicious cycle, ultimately leading to cable fires, causing unexpected losses and losses. Therefore, achieving real-time online temperature monitoring of cables and cable trenches is an important guarantee for the safe operation of enterprises. Cable joints are used for the connection between cable bodies, but have always been a weak link in the operation of cable systems. Among many accidents in high-voltage lines, safety accidents caused by poor contact of cable joints are the most common. The increase in temperature of cable joints increases the contact resistance at the joints, leading to overheating of cable joints, exacerbating insulation aging and even causing insulation breakdown, posing a serious threat to the safe operation of the power system. Therefore, if real-time and effective monitoring of temperature changes during the operation of cable joints can be achieved, it is of great significance to achieve online monitoring of cable joints and improve the safe operation of cable lines.

Why do cable joints need temperature measurement

In the power system, there are many cable joints, such as bus joints, switch contacts, v.v. Due to the high voltage and high current carried by transmission cables, cable joints are crucial. In high-voltage transmission lines, poor cable joints gradually increase the resistance at the joints, causing the temperature to rise. When the temperature reaches a certain level, the cable joints are burned, resulting in safety accidents. The existing temperature monitoring devices mostly use electronic temperature sensing devices for monitoring. However, due to the high voltage and high current conveyed by cables, electronic sensing devices are prone to electric shock accidents due to the inability to isolate high voltage through wires. Therefore, the application of electronic sensing devices in high voltage and high current temperature monitoring is greatly limited. Although there are fiber Bragg grating temperature sensing devices that can be applied now, the demodulation equipment cost of fiber Bragg grating sensing devices is high and currently difficult to popularize.

What are the traditional methods for temperature measurement of intermediate joints in power cables

At present, the temperature measurement method for cable joints mainly uses thermocouples or infrared detection technology to detect the outer surface temperature of cable joints. However, the measurement results obtained by this method are not only easily affected by external environmental temperature and air convection, but also by the interference of strong magnetic fields in the joints, making accuracy difficult to guarantee;

What are the advantages of a fluorescent fiber optic temperature measurement system for cable heads

1. The cable head fiber optic temperature measurement system fully considers the dispersion of the monitoring area and the complexity of the working environment, such as strong electromagnetic interference, temperature changes, etc., and takes corresponding measures. It has usability and reliability in special environments, and continuous real-time temperature measurement display and upload, as well as historical records.

2. The cable head fluorescent fiber optic temperature measurement host is equipped with remote monitoring function. By using the network on a remote monitoring computer, it is possible to understand the situation of each detection point on site, which is very convenient for leaders to timely understand the situation on site and is conducive to their decision-making and command.

3. The cable joint temperature measurement device has control function. Capable of transmitting information downwards, issuing operation and control instructions, and operating some controllable devices to improve automation level.

4. The cable head fiber optic temperature monitor has a high degree of automation and can achieve temperature monitoring of the entire factory’s cables on the monitoring host, including online temperature monitoring of power equipment and temperature monitoring of cable channels.

5. The cable temperature control system has high alarm accuracy and anti false alarm function. By using anti false alarm algorithms, the occurrence of false alarms can be effectively avoided, and faults in both the system and the detector itself can be monitored simultaneously. Equipped with sound and light alarms, the monitoring host can record and print events, and has historical data queries for easy post analysis.

6. Fluorescent fiber optic temperature sensors can be integrated with temperature measurement cable bus interfaces, with advantages such as small size and strong anti-interference ability.

7. The fluorescence fiber optic temperature measurement system has good compatibility. This system can connect and integrate temperature measurement systems, temperature sensing systems, and other power equipment, greatly saving system investment.