1.Necessity of temperature measurement at electrical contacts
The primary system of a power system is generally composed of power supply lines(including overhead lines and cables), transformers, busbars, switchgear and other electrical equipment. There are a large number of electrical connection points between them, and almost all electrical faults will cause the temperature change of the fault point due to the current flowing through it and generating heat. For example, overheating is a sign of large accidents and a major disaster area, such as overhead line connection, cable joint, cable middle connection, cable laying bend, partial discharge of high-voltage cable, dynamic and static contact of high-voltage switch cabinet and other connections, and low-voltage electrical connection.
2.Current Status
For many years, due to the limitations of the technical level, although infrared thermometer, infrared imager, temperature sensing cable, traditional point-type temperature measurement system have been used to solve the above problems, but can not achieve the switch cabinet such as circuit breaker, the connection point and contact temperature measurement. At present, domestic electric temperature measurement mainly uses infrared point measuring instrument and optical fiber temperature measuring instrument. However, the on-line method cannot solve the problem of high-voltage insulation, so the electrical equipment with limited space, such as the contact of high-voltage switch, basically operates in a completely unmonitored state, with major safety hazards.
3.Project background information
A domestic company specializing in industrial and AI solutions learned from a electrical complete plant in Egypt that they had a building construction project recently. The switchgear in the distribution room needs to be installed with wireless temperature measurement products. The company has found Acrel from the Internet. At present, they first need to make a set of demonstration cabinet to measure the temperature of the electric contact in the cabinet. Since there is no starting current, we will choose the second generation of wireless temperature sensor battery powered ATE200, with receiver ATC450-C, and make a local display on the cabinet.
4.Advantages of wireless temperature measurement products
In recent years, wireless temperature measurement products began to appear. The temperature sensor with built-in battery and wireless transmitter module is installed at each temperature measuring point. Due to its small size and no wiring, its electrical safety is guaranteed. The sensor periodically sends the temperature data wirelessly to the receiving unit, which sends the data to the receiving unit.
For the temperature detection of electrical equipment in the distribution room, the scheme of centralized reception and display is adopted, which greatly reduces the engineering installation workload and shortens the installation time, making it convenient to realize the temperature measurement transformation of important substation, and also has the same advantage for the construction of new stations.
Wireless temperature measurement products meet the demand of real-time temperature measurement at switch cabinet contacts in the distribution room, and have obvious advantages in reducing investment, engineering installation, maintenance labor and cost. The implementation of this project can effectively improve the safe and reliable operation level of the power supply system and reduce power failure, which is of great significance to ensure the normal production and reduce the loss caused by accidents.
5.Products used in this display cabinet
(1)Battery-powered wireless temperature sensor
Sensor installed in a heating area that collects temperature and transmits it wirelessly.
Name | Shape | Parameter instruction | Installation |
ATE200 | 35*35*17mm, L=330mm ( length*width*high, belt);-50℃~+125℃, Accuracy Class ±1℃, battery powered, life ≥5 years ;470MHz, open distance 150m. | Strap binding |
(2)Receiving unit
Name | Shape | Parameter Instruction | Installation |
ATC450-C | 65*45*28mm(length*width*high); DC24V power supply; RS485 interface along the way to receive 60 ATE400 wireless temperature sensor temperatures; Modbus protocol. | 35mm DIN rail screws fixed (φ4,36mm) |
(3)Displaying unit
Name | Shape | Parameter Instruction | Installation |
ARTM-Pn | Panel 96*96*17 mm, depth 65 mm, opening 92*92 mm,AC85-265V or DC100-300V power supply; along the way line RS485 interface; can receive 60 ATE wireless temperature sensors include ATE100M/100/200/400/ATE100P/ATE200P (matching ATC450); Modbus protocol. | Embedded panel installation |