switchgear temperature sensors Using fluorescent fiber optic temperature sensors-INNO

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. Aparelhagem de alta tensão, 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. Durante operação de longo prazo, 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. Portanto, timely detection of overheating issues in switchgear is the key to preventing such accidents from occurring.

Temperature measurement methods for high-voltage switchgear

A mudança de temperatura do quadro de distribuição de alta tensão é um processo gradual. Se a mudança anormal de temperatura puder ser detectada e tratada corretamente em tempo hábil, antes que afete a operação do equipamento de manobra de alta tensão, pode evitar quedas de energia ou até mesmo acidentes de incêndio causados pelo aquecimento do quadro de distribuição de alta tensão. Pode-se observar que o monitoramento da temperatura em tempo real de quadros de distribuição de alta tensão é muito importante. Atualmente, existem três esquemas de medição de temperatura para painéis:

1. Medição de temperatura infravermelha

O termômetro infravermelho é operado manualmente e flexível de usar, e se tornou um importante meio de detecção de temperatura para equipamentos de energia de alta tensão. No entanto, o volume do termômetro infravermelho é relativamente grande, e o espaço dentro do quadro é estreito, 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, névoa, interferência eletromagnética, etc., so its usage range is greatly restricted.

2. Medição de temperatura sem fio

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. Embora esta solução consiga a transmissão sem fio de sinais de temperatura, 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, sem adaptabilidade universal. Adicionalmente, 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. Adicionalmente, strict parameter selection requirements and insufficient reliability are required.

3. Medição de temperatura de fibra óptica

Due to its high insulation strength, forte resistência à interferência eletromagnética, resistência à corrosão, tamanho pequeno, e estrutura simples, 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 medição de temperatura de fibra óptica distribuída, grade de fibra óptica, e medição de temperatura de fibra óptica de fluorescência. Entre eles, fluorescence fiber optic temperature measurement has the most obvious advantages, with a long lifespan, no need for calibration, small probe size, e fácil instalação. The lifespan of fluorescence fiber optic temperature measurement for electrical equipment exceeds 20 anos, 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.

Resumindo, medição de temperatura de fibra óptica de fluorescência 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, um demodulador de temperatura, e um 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.