FJINNO provides a temperature monitoring system for switchgear contacts/busbars/incoming and outgoing lines, with 6-point temperature measurement for the switchgear and online temperature measurement for the switchgear. It replaces the infrared temperature measurement system, and the switchgear temperature measurement device has sensors that are resistant to high voltage and interference. The temperature measurement device can be used for multiple points in the high-voltage cabinet.
Temperature measurement method for switchgear
At present, the temperature measurement method used in the power supply system is infrared thermometer, which can only measure the temperature outside the switchgear and cannot directly and effectively monitor the easily heated parts such as cable heads and switchgear contacts inside the switchgear in a timely and effective manner. During operation, the contact points and outlet cable joints of the switchgear may generate heat due to aging or excessive contact resistance. If not detected and dealt with in a timely manner, it can easily cause fires and large-scale power outages, endangering the production of the hotline. To timely and effectively detect and handle the hot spots in the switchgear, achieving online temperature monitoring can timely and effectively detect and handle the heat generation in the switchgear, which is an important means to ensure the safe operation of high-voltage switchgear and cables.
Reasons for heating failure of electrical equipment in 35KV switchgear
(1) External thermal faults: External thermal faults of electrical equipment mainly refer to exposed joints that, due to poor crimping and other reasons, increase in temperature and contact resistance under the action of high current, resulting in a vicious cycle of hidden dangers. This type of fault accounts for over 90% of external thermal faults. According to data statistics, it can be seen that thermal faults of wire clamps and knife switch contacts account for 77% of the total external thermal faults, with an average temperature rise of around 30 ℃. The average temperature rise of other external joints is between 20 and 25 ℃. Based on testing experience and the amount of temperature rise, external faults can be divided into three types: mild, moderate, and severe.
(2) Internal thermal fault: The characteristic of internal thermal faults in high-voltage electrical equipment is that the fault point is sealed in insulation materials or metal shells, such as cable heads, contacts inside high-voltage switchgear, etc. Internal thermal faults generally generate heat for a long time and are relatively stable. They transfer heat to the surrounding conductors or insulation materials, causing local temperatures to rise. Therefore, internal faults in high-voltage electrical equipment can be diagnosed by detecting the temperature rise of the surrounding materials.
The functions of the fluorescent fiber optic temperature measurement system for 35KV switchgear
(1) Realize early prediction of equipment failures caused by overheating, and take preventive measures;
(2) When an overheating fault occurs, the system can provide an alarm and accurately locate the overheating position, guiding maintenance work.
(3) Visually display the specific locations and names of cable joints, equipment, and bus temperatures, and continuously monitor temperature in real-time. Save historical data as a basis for accumulating operational experience and analyzing accidents.
(4) Equipped with RS485 network interface, it can be connected to the management network within the station to achieve information sharing. Computers connected to the local area network within the station can also have temperature display and alarm functions. The host installed in the main control room and connected computers can automatically display corresponding alarm prompts.
(5) The fiber optic temperature online monitoring and control system, as a substitute for traditional temperature sensing fire detectors, has advantages such as high accuracy, fast data transmission and reading speed, good adaptive performance, and accurate and intuitive fault detection. It realizes many functions that traditional temperature measurement cannot achieve and problems that cannot be solved on site.
(6) Different alarm temperatures can be set for each temperature sensor through the system as needed. When the temperature reaches the predetermined value, the system alarms and displays the position of the faulty cable head.
(7) The system can analyze and judge whether the temperature of the switchgear and cable heads is normal or not, and alarm potential accidents based on the trend of temperature changes. It has functions such as over temperature alarm, abnormal temperature rise alarm, automatic recording and printing of out of limit accidents, and accident recall.
Advantages of FJINNO switchgear fiber optic temperature measurement system
1. Stable operation. The fiber optic temperature measurement system has the function of online collection, monitoring, and analysis of on-site temperature. These analyses include over temperature analysis, temperature rise trend analysis, temperature gradient analysis, and automatic environmental temperature compensation. It can also make alarms, comparisons, historical records, and other processing to ensure that handling is done before cable accidents occur. These methods are all based on extensive on-site practice and have high reliability and accuracy.
2. Visual display
The temperature measurement system of the switchgear fully utilizes the advantages of temperature monitoring, displaying the temperature value diagram of the switchgear intuitively on the software interface, and displaying the distribution positions of the switchgear contacts and cable joints in the switchgear layout diagram, which can display the temperature value of the measured point in real time and intuitively. The historical record analysis function predicts fire accidents in switchgear and cable joints, and saves the temperature changes at all measurement points since the system installation. By selecting different measuring points and time periods as needed, the operation of the switchgear and cable joints can be comprehensively analyzed. Based on the trend of temperature rise, the aging degree of switchgear and cable joints can be predicted early, and the possible locations of overheating faults can be determined, providing a basis for equipment maintenance.
3. Flexible parameter settings
The fiber optic temperature measurement device for switchgear meets various complex on-site requirements. Flexible parameter settings make the system’s analysis and alarm functions more comprehensive. Users can flexibly configure parameters such as recording intervals, recording methods, temperature alarm values, and temperature trend alarm values based on the actual situation on site.
4. The comprehensive online device self inspection function effectively ensures the safe operation of the equipment. The system has device self inspection function and self diagnosis ability, which facilitates equipment inspection and maintenance work, while also ensuring the normal and effective operation of the equipment.
The fluorescent fiber optic temperature measurement system is very suitable for online monitoring of high-voltage switchgear and cable heads. Currently, it is mostly used in 35/10kV power supply systems across the country. Each fluorescent fiber optic terminal is connected to a fiber optic temperature sensor corresponding to a temperature measurement point, which is easy to install and implement and easy to expand. Practice has proven reliable operation, timely detection of hidden dangers, achieving predictive control of equipment, effectively reducing power supply accidents, and providing a basis for planned maintenance. It is worth promoting and applying on other equipment that requires online temperature measurement.