The practical application of fluorescent fiber optic temperature sensors

1. Oil immersed transformer: For high-voltage electrical equipment such as oil immersed transformers, when working in high voltage, high current, and magnetic field environments for a long time, some connections and other parts may generate heat due to aging or excessive contact resistance, leading to heat accumulation; Heating up increases the loss of high-voltage electrical equipment. If the heat dissipation is poor, it can also endanger the normal operation of the equipment, and the consequences can be serious, leading to equipment failure

The negative social impact and economic losses are immeasurable. In the operation accidents of transformers, winding faults account for a large proportion, among which insulation aging, transformer winding burnout, and breakdown accidents caused by overheating of the windings account for a considerable proportion; For transformers, the winding temperature plays a decisive role in the aging of insulation materials, so accurate measurement of transformer winding temperature is particularly important. At present, there are two methods for measuring the hot spot temperature of transformer windings: thermal simulation measurement method (winding thermometer) and indirect calculation measurement method. The winding thermometer is an additional current matching device and electric heating element on the basis of the oil level thermometer, which reflects the heat of the transformer winding through temperature superposition; This temperature measurement method is simple, but has a large error. The indirect calculation measurement method calculates the winding hot spot temperature by calculating various key parameters and transformer load current values.

In recent years, fiber optic technology has experienced rapid development and widespread application, and the application of fiber optic in the field of sensing technology has received attention from people. The characteristics of fiber optic sensors are good electromagnetic insulation performance, high voltage resistance, corrosion resistance, and high temperature resistance. They can be used in harsh conditions such as strong electromagnetic fields and strong radiation. With the development of fiber optic sensing technology, more and more countries are paying attention to direct measurement methods, which are used in transformer windings

Directly embed fiber optic sensors and use temperature measuring instruments to measure and display winding temperature. Unlike the traditional method of measuring the top or bottom oil temperature, fiber optic temperature measurement can be directly achieved through sensing sensors placed in the winding to achieve true and accurate measurement of hot spot temperature, which has the advantages of direct, real-time, and accurate measurement.

2. Switch cabinet: Its heating parts are mainly concentrated at the dynamic and static contacts and the busbar connection, which are basically caused by aging and increased contact resistance. Due to the enclosed equipment and limited space, the heating in these parts of the station switchgear cannot be detected in a timely manner. Based on the advantages of fluorescence technology, the temperature of each heating part can be detected online in real time. The signal can be uploaded to the background or the mobile phone of the on duty personnel, making it convenient for maintenance personnel to conduct timely and targeted maintenance, improving maintenance efficiency.

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