distributed temperature sensing fiber optic cable，fiber-optic distributed temperature measurement

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

Why does the insulation layer of power cables require temperature monitoring

The performance of power cables is the key to determining the reliability of power supply for the transmission line, and even the key to the safe and stable operation of the power grid. The performance of cables is closely related to the quality of their insulation layer.

The insulation layer of cables inevitably experiences damage and aging over time due to factors such as corrosion in the surrounding environment and long-term operation. In the past, the underground environment where power cables were laid was more complex and secretive compared to overhead lines. It is particularly important to conduct real-time online monitoring of power cable operation lines, control their operating environment, perceive their insulation performance in advance, and ensure the safe and stable operation of the lines. Research has shown that the insulation layer performance of power cables is linearly related to the surface temperature of cable insulation. We can obtain the performance of power cable lines by detecting the surface temperature of cable insulation layer, thereby identifying real-time operating data, analyzing equipment risks, improving the fast fault handling mechanism, and ensuring the temperature operation of the power grid.

The method of temperature monitoring system for power cables

1. In the power cable monitoring system, traditional temperature monitoring methods are divided into non-contact and contact methods in terms of usage. Non contact temperature measurement is mainly based on infrared radiation temperature measurement, and the monitoring results are easily affected by the emissivity of the object and the surrounding environment. Its anti-interference ability and monitoring accuracy are not high. The measurement environment is also limited to the high temperature range, and low temperature conditions can easily cause significant errors. And due to the fact that power cables are usually laid in narrow cable trenches or directly buried underground, the infrared radiation temperature measurement method is severely limited and not suitable for large-scale measurement.

2. Contact temperature measurement mainly includes thermocouples and thermistors. Generally, temperature sensors use digital or platinum electric contact measurement methods. For example, platinum thermistors are used as sensitive components attached to the surface of power cables to collect their temperature, and then upload the data to the upper computer for processing. However, thermocouples, as sensitive components, are electrical signal sensors that operate in an environment with high frequency alternating strong electromagnetic fields. They are inevitably affected by electromagnetic interference generated by the space around the power cable, causing the wire itself to generate current, thereby affecting the accuracy of the measured data, and even affecting the cable itself. In severe cases, this can lead to short circuits in the power cable line.

3. The fiber optic temperature measurement system effectively avoids the electromagnetic interference factor of high-frequency alternating strong electromagnetic field. It has inherent passive characteristics. Fiber optic sensors use light as the carrier of sensitive information and fiber optic as the medium for transmitting sensitive information. Due to its unique characteristics of being free from electromagnetic interference, corrosion resistance, real-time monitoring without sources, electrical insulation, good explosion-proof performance, small size, light weight, winding ability, high sensitivity, long service life, long transmission distance, and easy maintenance, it has been widely used.