Ankerui Huanan
Abstract: The operation stability of the high-voltage power supply and distribution system is closely related to the temperature of the connection points of electrical components. By comparing with the traditional temperature measurement method, the real-time online wireless temperature monitoring solves the problem that the temperature of each connection point inside the sealed high-voltage switchgear cannot be detected. It meets the requirements for safe and stable operation of the power supply system, reduces labor intensity, and improves personal safety. The use of radio frequency technology to transmit temperature information avoids the occurrence of creepage accidents caused by the reduction of insulation due to the accumulation of dust, which is safe and reliable.
Keywords: real-time online; wireless; temperature; monitoring
With the continuous advancement of blast furnace intensive smelting, there are higher requirements for the operation stability of high-voltage power supply and distribution systems. Moreover, in order to achieve better and higher economic benefits due to fierce competition in the steel industry, it is imperative to reduce staff and increase efficiency. In the high-voltage power supply and distribution network of the metallurgical industry, the connection points between many high-voltage electrical appliances and equipment are the weakest link in power transmission. With the increase of load and the vibration and dust pollution of long-term operation, the connection point will heat up and form a vicious circle: temperature rise, expansion, contraction, oxidation, resistance increase, and heat up again until an accident occurs.
It takes a period of time for a fault to go from heating to an accident, and it is completely possible to detect abnormalities early and prevent them, reducing or eliminating the occurrence of electrical accidents. At present, the commonly used method for measuring the temperature rise of the high-voltage connection point of electrical equipment in China is to measure the temperature point by point with a temperature-indicating wax sheet or regularly use an infrared thermometer. The temperature-indicating wax sheet is obviously backward, and the method of point-by-point temperature measurement with an infrared thermometer has many disadvantages, which can easily lead to close contact with high-voltage charged objects and threaten personal safety, large measurement errors, and requires a lot of manpower and material resources. It can only be inspected regularly, the cycle is long, and the probability of failure due to missed inspection is very high. At present, the positions of circuit breakers, knife switches, moving and static contacts and other equipment inside the updated handcart switch cabinet are hidden, and the infrared thermometer can no longer perform manual inspection and temperature measurement. Therefore, it is very necessary to monitor the temperature change of the high-voltage connection point in real time.
1 Overview of real-time online temperature monitoring and early warning system
Infrared real-time online wireless temperature monitoring and early warning system can not only save a lot of manpower and material resources, but also has high temperature measurement accuracy, fast response, small size, easy installation, flexible networking, and Real-time online, strong anti-interference and other advantages, it is a revolution of the traditional temperature measurement method.
1.1 Composition and function of real-time online wireless temperature monitoring and early warning system
1.1.1 Wireless temperature sensor
Place a wireless temperature measurement and sending device at each temperature measurement point, that is, a wireless temperature sensor. The wireless temperature sensor consists of three parts: control unit, wireless data transmission and temperature measurement. After measuring the temperature, the temperature data is transmitted to the temperature measurement communication terminal by wireless. Each wireless temperature sensor has a unique ID number, and the installation location of each sensor is stored in the computer database of the temperature monitoring workstation in one-to-one correspondence with the ID number during on-site installation and use.
1.1.2 Temperature measurement communication terminal
Responsible for receiving the temperature data measured and sent by each wireless temperature sensor, and connecting through the bus, responding to the management software command to upload the temperature measurement data to the management computer. A temperature measurement communication terminal can receive temperature measurement data from multiple sensors. In order to ensure the response speed of the terminal, it is stipulated that a terminal can receive and manage up to 100 probes. The ID numbers of the probes managed by each terminal are downloaded to the terminal through special configuration software during project implementation.
1.1.3 Temperature monitoring workstation
A temperature monitoring workstation is set up in the power distribution room, mainly a PC computer, which is connected to each temperature measurement communication terminal through an RS485 communication interface converter.
The temperature monitoring computer collects the operating temperature data of each monitoring point from the temperature measurement communication terminal, saves them in the database for a long time, displays the temperature change curve of the monitoring point in real time, and analyzes them. Once the temperature is found to be overheated or rises sharply to the set alarm temperature Call the police.
1.2 Installation of real-time online wireless temperature monitoring and early warning system
1.2.1 System configuration
Combined with the requirements of each connection point of the mid-mounted or fixed high-voltage switchgear on site, taking the KYN27B-12Z mid-mounted switchgear as an example, 9 points need to be installed in each side of the switchgear, that is, the upper port of the handcart circuit breaker is three-phase, the lower part of the circuit breaker The three-phase connection between the three-phase port and the cable inlet (or outlet) cable terminal is three-phase. According to the total number of installed temperature measurement points, a corresponding temperature measurement communication terminal is equipped. (100 temperature measurement points are equipped with 1 temperature measurement terminal)
1.2.2 Support optical fiber remote transmission function
After the system is debugged and running normally, the temperature signal of the system measuring point in the workstation can be transmitted to other power distribution rooms by using the optical fiber remote transmission technology to realize remote real-time online temperature monitoring.
1.3 Advantages of real-time online wireless temperature monitoring and early warning system
The front end of the system adopts a wireless temperature sensor, which can be quickly and conveniently installed on the contact point of the high-voltage electrified body to accurately track the temperature change of the heating point;
(2) Using radio frequency technology to transmit temperature information, the equipotential of the collector and the collected point is realized, which is safe and reliable.
(3) The cabinet terminal can accurately report the temperature rise of all heat-prone parts of the tested high-voltage equipment during operation, providing a reliable data basis for the safe operation of the equipment;
⑷The system data can be visually displayed through the man-machine interface of the monitoring center, the geographical distribution map, the operating parameters of the contact temperature, the warning information, and the historical parameters in the form of graphs, tables, curves, bar graphs, etc., so as to discover hidden dangers in time and eliminate hidden dangers to maximize Reduce accidents.
(5) Compared with the traditional temperature display wax sheet and infrared temperature measurement, the system has the advantages of high temperature measurement accuracy, fast response, small size, easy installation, flexible networking, real-time online, and strong anti-interference. Optical fiber temperature measurement technology is easy to break, easy to break, and not resistant to high temperature. After accumulating dust, it is easy to reduce the insulation and cause creepage accidents, and the wiring in the cabinet is difficult, and the engineering construction is not flexible.
2 Application effect of real-time online wireless temperature monitoring and early warning system
(1) After the system is put into normal operation, the inspectors in the high-voltage power distribution room no longer use infrared thermometers to measure the temperature manually, which reduces labor intensity, improves personal safety, and produces significant economic and social benefits.
(2) The real-time online detection of the actual temperature in the switchgear can obtain first-hand operating data for fault location, which is convenient for timely discovery of hidden dangers, and reduces or eliminates the occurrence of electrical accidents caused by heat generation.
(3) Provide reliable data for the maintenance and fastening of high-voltage switchgear, ensuring the stability of power supply.
(4) The application of the real-time online wireless temperature monitoring and early warning system solves the problem that the temperature of each connection point inside the middle-mounted and fixed sealed high-voltage switchgear cannot be detected, meets the requirements for safe and stable operation of the power supply system, and achieves the expected goal.
3 Ankerui Wireless Temperature Measurement System Introduction
Ankerui wireless temperature measurement and monitoring system is based on the requirements of the current wireless temperature measurement system, on the basis of extensively soliciting opinions from users and experts, fully absorbing the current successful cases of domestic and foreign manufacturers, and combining the rich experience of Ankerui for many years, It is a professional wireless temperature measurement software designed by adopting object-oriented layered distributed design idea and combining automation technology, computer technology, network technology and communication technology.
3.1 Acrel-2000T wireless temperature measurement system structure
The Acrel-2000T wireless temperature measurement and monitoring system communicates directly with the equipment on the bay layer through the RS485 bus or Ethernet (as shown in Figure 1). The system design follows the international standard Modbus-RTU, Modbus TCP and other transmission protocols, which is safe, reliable and open performance has been greatly improved.
Acrel-2000T wireless temperature measurement and monitoring system has the functions of remote signaling, telemetry, remote control, remote adjustment, remote setting, event alarm, curve, bar graph, report and user management. It can monitor the equipment operating status of the wireless temperature measurement system, realize rapid alarm response, and prevent serious failures.
The main features of Acrel-2000T wireless temperature measurement and monitoring system are open system structure, strong hardware compatibility, good software portability, and rich application functions. The system has powerful processing capability, fast event response, friendly man-machine interface, and convenient means of expansion. The design of its software system is based on the design specifications of software engineering, with reasonable module division and simple and clear interface, mainly including main control module, man-machine interface, graphic configuration, database management system, communication management and other major modules.
Figure 1 Acrel-2000T wireless temperature measurement system structure diagram
3.2 Acrel-2000T wireless temperature measurement system function
■Real-time monitoring
Acrel-2000T wireless temperature measurement and monitoring software has a friendly man-machine interface, which can visually display the temperature data of each temperature measurement node and information about faults and alarms in the form of a power distribution diagram
■Temperature query
Temperature history curve (1 minute, 5 minutes, 60 minutes optional)
■Run report
Query the operating temperature report of each circuit equipment.
■Real-time alarm
The wall-mounted wireless temperature measurement and monitoring equipment has a real-time alarm function, and the equipment can issue alarms for events such as temperature exceeding the limit.
■The device provides the following alarm methods:
a. The event alarm window pops up.
b. Real-time voice alarm function, which can issue voice alarms for all events.
C. SMS alarm, which can send alarm information SMS to the designated mobile phone number (optional SMS modem is required).
■Historical alarm query
Acrel-2000T wireless temperature measurement and monitoring system can store and manage all alarm event records, which is convenient for users to trace the history of the system and alarm events, query statistics, and analyze accidents.
■User rights management
In order to ensure the safe and stable operation of the system, the Acrel-2000T wireless temperature measurement and monitoring system has set up a user authority management function.
Unauthorized operations (such as database modification, etc.) can be prevented through user rights management. The login names, passwords and operation rights of users at different levels can be defined to provide reliable security for system operation, maintenance and management.
■Fix value setting
It is used to modify the high temperature setting value and over temperature setting value.
■WEB (optional)
The display page displays general information such as the number of substations, transformers, and monitoring points, equipment temperature, communication status, power consumption analysis, and event records. The home page displays general information such as the number of transformers, the number of circuits, active power, reactive power, power consumption, and event records of the station. You can switch to the interface that needs to be viewed through real-time monitoring, transformers, and communication modules.
The real-time data curve can monitor the temperature, voltage, current and power curve information of each loop.
The wiring diagram page reflects changes in electrical parameters in real time through a diagram, including information such as measurement quantities and semaphores (the semaphores require the circuit breaker to provide auxiliary contact support).
The energy consumption statistics page displays the peak power and peak power consumption of each circuit, the trend curve of power and electric energy, the chain ratio of electric energy, and the ranking of electric power consumption.
Operation and maintenance management\communication status display monitors the communication status of the access system equipment.
■Mobile APP (optional)
The equipment data panel displays the electrical parameter data, temperature data and curves of each equipment.
3.3 Product Selection of Ankerui ARTM Series Wireless Temperature Measurement Terminals
Ankerui electrical contact wireless temperature measurement solution consists of wireless temperature sensor, transceiver and display unit. The temperature sensor is directly installed on the moving contact, static contact, cable connector, busbar and other heating contacts of the circuit breaker, and the temperature measurement data is transmitted to the receiving device through radio frequency technology, and then communicated by the receiver 485 to the temperature measurement terminal or wireless measurement temperature system (Figure 2).
Figure 2 Structural diagram of electrical contact online temperature measurement
3.3.1 Ankerui Wireless Temperature Sensor
There are 5 types of wireless temperature sensors, corresponding to bolt fixing, watch strap fixing, cable tie binding, alloy sheet fixing and other installation methods. According to the requirements of different substations, the matching sensor can be selected according to the different power supply mode and installation location of the sensor, considering the factor of convenient installation.
3.3.2 Ankerui Wireless Transceiver
There are 3 types of wireless temperature measurement transceivers, which receive temperature data through wireless radio frequency. The transceiver is matched according to different sensor models, and the transmission distance of the sensor determines whether the receiving device can receive in multiple cabinets.
3.3.3 Ankerui display terminal
The display device is connected to the transceiver through RS485, and can be embedded in the cabinet. If it is inconvenient to open the cabinet, it can also be installed on the wall in the power distribution room. It is convenient for operators to check the real-time temperature of electrical nodes on site, and at the same time, they can also check the site conditions in the background system through RS485 or Ethernet communication.
4 Epilogue
The application effect of the real-time online wireless temperature monitoring and early warning system is very good. It realizes real-time online temperature measurement and monitoring of high-voltage switchgear and electrical equipment in the environment of high voltage and high current, because this technology is wireless data transmission. Problems such as pollution flashover and high-voltage insulation reduction, and the friendly man-machine interface have preliminarily realized the intelligent management of high-pressure switchgear, and have good application prospects and promotion value.
【references】
[1] Ren Yanxia. Research and Application of Real-time Online Wireless Temperature Monitoring and Early Warning System, Science and Technology Communication [J]. 2011(4): 146- 148.
[2] Shao Xiaoming, Liu Hantao, Zhao Yuhua. Application of real-time online wireless temperature monitoring and early warning system in high voltage power supply and distribution system of ironworks
[3] Ankerui Enterprise Microgrid Design and Application Manual 2019.11 Edition