switchgear temperature sensors Using fluorescent fiber optic temperature sensors

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

With the continuous development of the national economy, the power industry has entered an era of rapid development, and the safe and stable operation of power system equipment is particularly important. High voltage switchgear, as an important equipment in power plants and substations, plays an important role in switching power lines, line fault protection, and monitoring operating energy data. During long-term operation, the temperature of the heating part inside the high-voltage switchgear cannot be monitored in real time, which ultimately leads to the occurrence of fire accidents and large-scale power outages. Therefore, timely detection of overheating issues in switchgear is the key to preventing such accidents from occurring.

Temperature measurement methods for high-voltage switchgear

The temperature change of the high-voltage switchgear is a gradual process. If the abnormal temperature change can be detected and handled correctly in a timely manner before it affects the operation of the high-voltage switchgear, it can avoid power outages or even fire accidents caused by the heating of the high-voltage switchgear. It can be seen that real-time temperature monitoring of high-voltage switchgear is very important. Currently, there are three temperature measurement schemes for switchgear:

1. Infrared temperature measurement

The infrared thermometer is manually operated and flexible to use, and has become an important means of temperature detection for high-voltage power equipment. However, the volume of the infrared thermometer is relatively large, and the space inside the switchgear is narrow, making it impossible to install an infrared thermometer probe; Its production cost is high, the accuracy is average (related to distance), and it cannot achieve online real-time monitoring; Infrared temperature measurement is a non-contact temperature measurement method, which cannot accurately measure the temperature at key points due to its obstruction; Its temperature measurement accuracy is easily affected by environmental factors such as light intensity, fog, electromagnetic interference, etc., so its usage range is greatly restricted.

2. Wireless temperature measurement

The existing wireless temperature measurement solutions mainly use batteries or CT to power the temperature measurement chip, and send temperature signals through the wireless chip. Although this solution achieves wireless transmission of temperature signals, it is an active solution. Battery power supply requires regular battery replacement, and the battery’s ability to withstand high temperatures is poor, which affects power operation; The use of CT energy harvesting results in a large sensor volume and a significant impact on energy harvesting efficiency due to its placement, lacking universal adaptability. Additionally, if the joint current is small, electrical energy cannot be extracted, and if the joint current is large, it is easy to burn out the CT until the sensor is burned out. Additionally, strict parameter selection requirements and insufficient reliability are required.

3. Fiber optic temperature measurement

Due to its high insulation strength, strong resistance to electromagnetic interference, corrosion resistance, small size, and simple structure, fiber optic transmission systems are particularly suitable for online measurement of temperature parameters in power systems. The fiber optic thermometer uses optical fibers to transmit signals, and its temperature sensor is installed on the surface of a charged object. The thermometer is connected to the temperature sensor using optical fibers. Fiber optic temperature measurement can be divided into various methods such as distributed fiber optic temperature measurement, fiber optic grating, and fluorescence fiber optic temperature measurement. Among them, fluorescence fiber optic temperature measurement has the most obvious advantages, with a long lifespan, no need for calibration, small probe size, and easy installation. The lifespan of fluorescence fiber optic temperature measurement for electrical equipment exceeds 20 years, and there are many products used in environments with extremely high requirements such as 500kV transformer windings, which have been proven to be safe and reliable.

In summary, fluorescence fiber optic temperature measurement technology has significant advantages in temperature measurement of electrical equipment in power plants and substations. Compared to infrared temperature measurement, it can achieve online monitoring with high accuracy; Compared to wireless temperature measurement, it is not affected by electromagnetic interference, has a small size, and a long lifespan.

Composition and working principle of a fluorescent fiber optic temperature measurement and fire monitoring system

The fluorescence fiber optic thermometer consists of a display instrument, a temperature demodulator, and a fluorescence fiber optic sensing probe. The measuring point is the static contact of the high-voltage switchgear. After installing the fiber optic probe on the static contact of the switchgear, the temperature information is transmitted through the fiber optic to the demodulator for calculation, and a display function is provided to achieve online temperature monitoring of the switchgear contacts.