CN102890856A - Junction temperature sensing device for transmission equipment - Google Patents

Abstract

The present invention proposes a power contact sensing device. The wireless temperature sensor is connected to the network of the handheld collector, and the temperature information collected by the handheld collector is transmitted to the monitoring computer through the data transmission base station. Since the present invention consists of a wireless temperature sensor and a hand-held acquisition terminal to form a temperature detection device, which is sent to a monitoring computer through a data transmission base station, it can detect the temperature status of power equipment in a timely and effective manner, and perform system recording and monitoring through the network, so as to find problems in time And solve the problem, prevent the transmission equipment from causing accidents due to excessive temperature. It is suitable for application as a temperature monitoring device for power transmission equipment and electrical equipment contacts.

Description

Contact temperature sensor device for power transmission equipment

technical field

The invention proposes equipment in the field of power transmission, specifically a temperature sensing device for a contact point of the power transmission equipment.

Background technique

With the rapid development of the national economy, the operation of the national economy relies more and more on the supply of electric energy. The safe operation of the high-voltage and ultra-high voltage backbone transmission network is directly related to the safe operation of the entire power grid, and it is also related to national economic security and social stability. . Power transmission lines are widely distributed, and equipment testing and maintenance require a lot of manpower and material resources. The equipment temperature parameter is an important parameter to characterize the health status of the equipment, and it is also a necessary indicator for routine inspections. The equipment operating temperature can reflect the operating status of the equipment in a timely manner and provide a reliable basis for equipment testing and maintenance.

The fittings, wires, joints and other joints of the conductor part of the transmission line may cause heat due to oxidation corrosion, loose joints, etc., which affects the safety and power transmission performance of the power system. In the current transmission line inspection operation, the line inspector conducts routine inspection once a month. Generally, when the appearance of the joint changes, the far-infrared device is used to measure the temperature. After the measurement is completed, the data is analyzed and converted to obtain whether the standard is exceeded. The process is relatively complicated and highly dependent on labor, and errors or mistakes are prone to occur in the measurement and conversion links. When the load is about to occur or has undergone major changes, line inspectors are required to conduct special inspections, which has a heavy workload and weak timeliness. Therefore, in the line inspection operation of transmission lines, there is an urgent need for an effective technical means that can accurately measure the temperature of key points, reflect whether the temperature exceeds the limit in real time, and reduce the workload of line inspectors.

In recent years, the continuous progress of digital wireless communication technology, the application is more and more extensive. From the perspective of technology and materials, it is possible for us to integrate sensors, microprocessors, radio frequency transmission chips, batteries, etc. into a very small package to make a smart wireless sensor, which makes the problems that were difficult for us to solve in the past become simple and easy. OK.

At the same time, microwave digital radio frequency technology has made great progress in recent years, and the development of wireless digital communication technology has benefited from the comprehensive development of many technologies. The key technologies involved generally include: chip technology, antenna technology, wireless transceiver technology, data conversion and coding technology, and electromagnetic propagation characteristics.

At present, in the domestic power system field, the temperature detection of the primary equipment of power transmission and transformation mainly adopts the infrared thermal imager method. In theory, this method can measure the temperature between 0 and 200 ° C, and the basic error is ± (1% × t + 0.5 %), the accuracy is high, but in actual work, due to the influence of the site environment, meteorological factors, measurement angle and operation method, the measurement accuracy and effectiveness often have a gap with the theoretical value. At the same time, measuring close to the target equipment will bring safety hazards to the inspectors themselves, manual data recording will reduce work efficiency and data accuracy, poor function scalability and other factors make infrared technology in the current background application. limitation.

The working principle of the general wireless sensor network temperature measurement system: the wireless temperature sensor is directly installed near or on the monitored equipment, and each sensor has a unique ID. During the actual installation, the physical location of the monitoring point should be recorded and entered into the host database together. The sensor starts measurement and sends the status data of the monitored point at regular intervals, and these data are transmitted to the base station through the wireless channel to upload the data to the host. The host has the functions of monitoring data collection, graphical display, threshold comparison, monitoring and early warning, standardized data communication, etc., to realize intelligent online monitoring of equipment status.

The working principle of the contact sensing temperature measuring device system for transmission line inspection: each wireless sensor has a unique ID, and the actual physical address of the monitoring point is corresponding to the sensor ID one by one, and is entered into the handheld collection terminal. The wireless temperature sensor can record the highest temperature, the lowest temperature and the moment of occurrence of the monitoring data in real time. When the handheld collection terminal is close to the measured point, the wireless sensor will record the measurement data and send it to the external wireless data transmission base station of the handheld collection terminal. , the external wireless data transmission base station will automatically answer, and record the wireless sensor’s sending time, ID number, user ID number, battery capacity and other information into the FLASH (temporary) memory of the handheld external wireless data transmission base station, After binary conversion, the data is imported into the background software of the handheld terminal, and the background software analyzes and processes the data to form an inspection report, prompts possible faults in time, and provides technical support for regular maintenance.

Through the analysis of the principles and works of the two different systems, it can be seen that the handheld acquisition terminal effectively combines the monitoring host system of the general wireless sensor network with the data transmission base station, so as to realize the wireless temperature measurement of the equipment. In addition, the general wireless sensor itself cannot record the highest temperature, the lowest temperature and the time of occurrence of the monitoring data in real time, but the wireless sensor of the transmission line temperature intelligent inspection system can support it.

Contents of the invention

In order to realize the monitoring of the junction temperature of electric power equipment, the present invention proposes a junction temperature sensing device of power transmission equipment. The device solves the technical problem of temperature sensing and monitoring of power equipment through the combination of wireless temperature sensor and hand-held acquisition terminal, and transmits the data signal to the monitoring computer through the data transmission base station.

The solution adopted by the present invention to solve the technical problem is: the wireless temperature sensor is connected to the hand-held collector through the network, and the temperature information collected by the hand-held collector is transmitted to the monitoring computer through the data transmission base station.

Positive effect, because the present invention is made up of temperature detection device by wireless temperature sensor and hand-held acquisition terminal, and sends to monitoring computer through data transmission base station, so can detect the temperature state of power equipment effectively in time, and carry out system recording and monitoring through network, so that Find and solve problems in time to prevent accidents caused by overheating of power transmission equipment. It is suitable for application as a temperature monitoring device for power transmission equipment and electrical equipment contacts.

Description of drawings

Fig. 1 is a schematic diagram of the signal connection between the wireless temperature sensor and the hand-held collector of the present invention

Fig. 2 is a schematic diagram of the signal connection between the wireless temperature sensor, the hand-held collector, the data transmission base station and the monitoring computer of the present invention

In the figure, 1. Monitoring computer, 2. Data transmission base station, 3. Wireless temperature sensor, 4. Hand-held collector.

Detailed ways

As shown in the figure, the wireless temperature sensor 3 is connected to the network of the hand-held collector 4 , and the temperature information collected by the hand-held collector is transmitted to the monitoring computer 1 through the data transmission base station 2 .

The handheld collector consists of a tablet computer and a USB external data transmission base station.

The configuration of device of the present invention:

1. The device is equipped with an 8.4-inch TFT SVGA multi-touch screen, USB2.0 interface, headphone jack and integrated microphone, and has Bluetooth transmission, GPS positioning system, handwriting input and wireless Internet access functions. Powered by lithium battery.

2. The handheld acquisition terminal is connected to the USB interface of the handheld device by connecting the external module of the data transmission base station, so as to combine the signal acquisition equipment with the monitoring host, and use 3G or Ethernet to connect to the network.

3. The wireless temperature sensor is composed of a 2.45GHz wireless transmitter and MCU. The wireless temperature sensor adopts the spread spectrum working mode, and the instantaneous communication rate is: 1Mbps. Due to the use of the spread spectrum communication mechanism, 65536 or more wireless temperature sensors can be accommodated within the effective range of a wireless data transmission base station at the same time, realizing Long-distance (>200 meters) highly reliable high-speed wireless data communication.

4. Plane installation or installation on a curved surface: when installing on a plane, fix the device on the plane of the temperature monitoring point. When installing on a curved surface, use a shape-preserving hoop. The material of the hoop must be non-magnetic bronze or stainless steel, and it should be fastened with elasticity to avoid relaxation after rigid fastening thermal expansion and contraction.

5. This device adopts a high-gain antenna, and the reading distance of the sensor can reach >100 meters, which can fully meet the user's requirements and help reduce the power consumption of the wireless temperature sensor. Because the background noise in the 2.45GHz frequency band is relatively low, it is beneficial to improve the sensitivity of the receiver so as to meet the use requirements with less power and reasonable price.

6. Hand-held collection terminals are independent of each other and do not interfere with each other. As long as they are within the range of communication transmission distance, they can simultaneously collect and receive data from wireless sensors.

7. Information synchronization and information aggregation between handheld terminals, use 3G or Ethernet to connect to the network, and realize end-to-end data communication, synchronization and information aggregation through software.

Technical issues to be resolved:

1. Network security: The security of the power system is related to the national economy and the people's livelihood, and the security of wireless sensor networks is particularly important in the power system.

2. Ultra-long life of sensors: Since the maintenance and replacement of sensors for power systems are extremely difficult, it is expected that the life of the sensor will be consistent with the life of the device under test to about 20 years, which is a challenge for sensor design.

3. High reliability of sensors in high-voltage environments: Since sensors used in power systems are usually installed in harsh working environments such as ultra-high electromagnetic fields, high temperatures, and high humidity, their protection design and reliability design are a serious challenge .

4. Reliable communication in a complex electromagnetic environment: In substations, transmission lines, user meter boxes and other environments, there are strong electric field interference, and there are many metal objects, which cause serious multi-wave and fading phenomena, and seriously trouble the reliability of communication.

5. High-efficiency network communication protocol: For wireless sensors used in power systems, battery life is a key issue. The main aspects that affect battery life are network communication protocols, measured target attributes, and sensor operating modes. The properties of the measured target cannot be changed, and the working mode of the sensor is usually fully optimized, so the network communication protocol will greatly affect the battery life of the sensor to a large extent.

Work process and design points of the present invention:

1. Wireless temperature sensor storage. On the basis of satisfying the collection, analysis and processing of temperature measurement data by handheld wireless temperature acquisition terminals, the ease of use, line technical parameters and data management and analysis functions are added to make it more convenient for patrol inspection. Study the self-storage function of the wireless temperature sensor, and grasp the temperature of the contact point of the transmission line under test in real time through a handheld wireless temperature collection terminal.

2. Ease of use and data analysis and processing of handheld collection terminals. The handheld device has the function of real-time display of the temperature of the external temperature and the contact point of the equipment, and can understand the change of the temperature according to the change of the load. The handheld device has the function of real-time display of the external temperature and the contact temperature of the equipment; it has some technical parameters and data editing functions such as the transmission line bar diagram. Background data processing, analysis, periodic comparison functions, etc. Photographic and hand-written memorandum functions.

3. Electromagnetic compatibility of wireless sensor network power applications: the interference of wireless sensors to power secondary equipment, the interference of wireless sensor networks to power secondary equipment is mainly the radio frequency interference of wireless sensor networks, and different application scenarios are adopted. measures to ensure the reliable operation of secondary equipment in the power grid. All radio frequency indicators of wireless sensor network products must meet the following standard requirements: GB/T 6113.2-1998 Radio disturbance and anti-interference measurement method. GB9254-1998 Limits and measurement methods of radio disturbance of information technology equipment. Avoid interference: All radio transceiver equipment should not be too close to avoid blocking interference. Transmission line application: Since there is basically no secondary equipment on the transmission line, as long as the above standards are met in this application scenario, it will not interfere with other equipment and can be used normally. The main measures are to limit the radiation power and the installation distance of relatively sensitive equipment, and to limit the installation location of wireless sensors. Sensitive locations cannot be installed if they cannot be proved to be safe and harmless.

Interference of power equipment on wireless sensor network communication: In power system applications, communication reliability problems are caused by various factors, and different technical means or multiple means are applied simultaneously to solve different reasons.

Aiming at the problem of penetration: In applications such as switching cabinets, as long as the shielding effect causes large signal loss, select an appropriate operating frequency and use the insulation window of the electrical cabinet as the radio wave leakage window to reduce signal attenuation. The actual measurement shows that 2.4 The GHz frequency band can be applied to most electrical cabinets, and the signal attenuation is within an acceptable range.

Aiming at the problem of fading: Due to the large and complex metal equipment in the substation, the distribution of field strength in the substation is uneven and unstable. decline.

For the problem of strong electromagnetic field interference: select the available frequency band with strong and weak interference field, adopt the DSSS modulation style with strong anti-interference ability and intelligent spectrum management technology based on cognitive radio technology, and dynamically select the frequency point with weak interference for antenna, but due to the sensor They are distributed in different physical locations, so their interference field strengths are also different, so an effective coordination mechanism and error control mechanism must be adopted when selecting communication frequency points.

High reliability of wireless sensors:

Reliability design: apply military product reliability design technology and life cycle management technology, analyze the characteristics of each link of product design and each component, use a large number of existing reliability design data, optimize design and reinforce weak components , Parallel and cold, hot backup and other design methods, and computer simulation design and computer reliability verification to ensure that the product reaches the design life and service life.

Reinforcement measures under high voltage environment: In addition to the above-mentioned design and verification methods, a special design is made for the high electromagnetic field environment of the power system. The antenna and other components in the high electromagnetic field environment adopt anti-static protection design and power frequency interference suppression design, and use high-temperature resistant lithium sub-batteries and industrial-grade and military-grade components to cope with high-temperature working environments. These technical means are used to ensure that the sensor can be used in harsh environments. Reliable work under high voltage environment.

High-efficiency network communication protocol: Single-hop communication mode is adopted between nodes and handheld collection terminals. In order to reduce node power consumption, communication efficiency must be improved. We have improved the antenna design of handheld collection terminals, using high-gain antennas and multiple Channel diversity technology effectively improves the communication distance and anti-fading ability, and realizes the 0dbm communication distance greater than 100m (open land), which is far superior to the current level of general radio communication in this frequency band (Bluetooth 10m), and the improvement of communication efficiency is also It means that less energy consumption is used to transmit more data to a farther target node, that is, the power consumption of the node is reduced.

Sending data is the link with the largest power consumption. To save power consumption, one is to reduce the transmission power, but this will affect the signal transmission distance. Another way is to reduce the transmission time, that is, to increase the communication rate. This method is more effective.

In order to improve the communication rate, it is very important to choose the modulation mode. Although the multi-phase modulation (16PSK), OFDM and other modulation modes have a higher communication rate within a given bandwidth, considering the signal-to-noise ratio, link budget, and system complexity and other factors, GFSK is the most efficient modulation style, so this system adopts high-efficiency GFSK modulation style to realize high-speed communication of 2MBPS, and the time to complete a frame of communication is less than 200uS, thus greatly reducing the working time of the transmitter. The duty cycle of the node is improved, and the power consumption of the node is greatly reduced.

Establish a transmission line temperature measurement pilot area, deploy the device system, and realize the collection of temperature information of the contacts on the transmission line equipment in the specified area.

1) It can comprehensively monitor the temperature status of the joints of related equipment on the deployment of transmission lines, avoiding the omission of sensitive temperature monitoring points, which may cause potential safety hazards and economic losses;

2) The wireless temperature sensor has its own data storage function, and finally the temperature measurement data from the last inspection to the current inspection can be obtained through the handheld wireless temperature acquisition terminal, and the highest and lowest values can be analyzed to predict the power transmission and transformation in advance. Potential safety hazards caused by excessive equipment temperature;

3) Through the GPS positioning of the handheld wireless temperature collection terminal, you can view and search the current position, name, voltage level, tower number and other information of the measured point to ensure the reliability and availability of the line inspection data, and standardize and supervise the entire inspection line ;

4) The handheld device has an instant display function of the external temperature and the contact temperature of the equipment, and can understand the temperature change according to the load change. The handheld device has the ability to display the temperature of the external temperature and the contact point of the equipment in real time;

5) It has some technical parameters and data editing functions of the transmission line bar diagram. Background data processing, analysis, periodic comparison functions, etc. Photographic and hand-written memorandum functions. the

Claims (9)

1. The contact temperature sensing device of power transmission equipment, characterized in that: the wireless temperature sensor (3) is connected to the network of the hand-held collector (4), and the temperature information collected by the hand-held collector is transmitted to the monitoring computer ( 1). 2. The temperature sensing device for the contact point of power transmission equipment according to claim 1, characterized in that: the hand-held collector is composed of a tablet computer and a USB external data transmission base station. 3. The contact temperature sensing device of power transmission equipment according to claim 1, characterized in that: the device is equipped with an 8.4-inch TFT SVGA multi-touch screen, a USB2.0 interface, an earphone jack and an integrated microphone, and has Bluetooth Transmission, GPS positioning system, handwriting input and wireless Internet access functions, powered by lithium battery. 4. The contact temperature sensing device of power transmission equipment according to claim 1, characterized in that: the hand-held acquisition terminal is connected to the USB interface of the hand-held equipment by connecting the external module of the data transmission base station, thereby connecting the signal acquisition equipment and the monitoring host In combination, use 3G or Ethernet to connect to the network. 5. The contact temperature sensing device of power transmission equipment according to claim 1, characterized in that: the wireless temperature sensor is composed of a 2.45GHz wireless transmitter and MCU; the wireless temperature sensor adopts the spread spectrum working mode, and the instantaneous communication rate is : 1Mbps, due to the use of spread spectrum communication mechanism, 65536 or more wireless temperature sensors can be accommodated within the effective range of a wireless data transmission base station at the same time, realizing >200 meters long-distance highly reliable high-speed wireless data communication. 6. The contact temperature sensing device of power transmission equipment according to claim 1, characterized in that it is installed on a plane or on a curved surface, and when installed on a plane, the device is fixed on the plane of the temperature monitoring point; when installed on a curved surface, It is installed in the form of a retaining hoop, and the material of the hoop must be non-magnetic bronze or stainless steel. 7. The temperature sensing device for the contact point of power transmission equipment according to claim 1, characterized in that: the device adopts a high-gain antenna, and the reading distance of the sensor reaches >100 meters. 8. The temperature sensing device for the contact point of power transmission equipment according to claim 1, characterized in that: the handheld collection terminals are independent of each other and do not interfere with each other. 9. The contact temperature sensing device of power transmission equipment according to claim 1, characterized in that: information synchronization and information aggregation between handheld terminals, network connection using 3G or Ethernet, and realization of end-to-multi-end connection through software Inter-data communication, synchronization and information aggregation.

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