CN204881917U - Cable intermediate head temperature on -line monitoring system based on fog computing technology - Google Patents

Abstract

The utility model discloses a cable intermediate head temperature on -line monitoring system based on fog computing technology belongs to cable temperature monitoring technical field. Including a plurality of center node, with a plurality of terminal node of center node communication connection, with all center node communication connection's GPRS network, with GPRS network communication connection's data management platform, every terminal node all includes intermediate head, temperature sensor, data acquisition module, the wireless transmitting module on cable, the cable and gets can power management module, center node including getting of connecting gradually can the power, center node module, data processing module and GPRS emission module, data management platform still includes the siren including built -in temperature measurement system software's server. The utility model has the advantages of stability is good, and temperature measurement is high, and is with low costs, and easy installation is longe -lived, convenient to use, but on -line monitoring.

Description

On-line temperature monitoring system for cable intermediate joints based on fog computing technology

technical field

The utility model relates to an on-line monitoring system for the temperature of a cable intermediate joint based on fog computing technology, which belongs to the technical field of cable temperature monitoring.

Background technique

The cable joint is also called the cable head. After the cable is laid, in order to make it a continuous line, each section of the line must be connected as a whole, and these connection points are called cable joints. The cable joints in the middle of the cable line are called intermediate joints, and the cable joints at both ends of the line are called terminal heads. The cable joint is used to lock and fix the incoming and outgoing lines, and play the role of waterproof, dustproof and shockproof. Its main function is to make the line unobstructed, keep the cable sealed, and ensure the insulation level of the cable joint, so that it can run safely and reliably. If the seal is not good, not only oil leakage will cause the oil-impregnated paper to dry up, but also moisture will invade the inside of the cable, reducing the insulation performance of the paper.

The intermediate joint is the weak link on the power cable line, which is prone to local overheating during operation. Therefore, online monitoring of its temperature is very important. On-line monitoring of intermediate joint temperature requires accurate, real-time, on-line recording of temperature data. Through the real-time temperature and historical temperature, not only can judge the aging condition of insulation, local hot spots, timely discover potential safety hazards, and ensure the reliability, stability, and economy of power system operation; it can also provide a basis for dynamic capacity expansion of power cables.

There will be an intermediate joint every 500m or so on the power cable line. Due to the variety of cable laying methods and the wide range of lines, this makes it difficult to monitor the temperature of the intermediate joint online. With the rapid development of sensor technology and communication technology, it is important to design and develop a more optimized online temperature measurement system for power cable intermediate joint temperature through comprehensive comparison of various new technologies and complementary advantages. significance.

In order to reduce the burden on the underlying data acquisition terminal, the data detected by the sensor is generally uploaded to the cloud server in real time, and then the actual operation of the cable is analyzed based on the data from the cloud server. However, applying cloud computing to the cable joint temperature online monitoring system will cause many problems. First of all, due to the large number of joints in the middle of the cable line, there are many data points that need to be detected on the multi-circuit line. If the data is uploaded to the cloud at the same time, it may cause data congestion, and the data cannot be uploaded to the cloud in time. This will lead to delayed alarm and so on. Secondly, the premise of cloud computing is to upload data to the cloud, otherwise data processing and analysis will not be completed. In order to solve these problems, this utility model uses a digital temperature sensor to propose an online monitoring system for the temperature of the cable intermediate joint based on fog computing technology. The system has reliable communication, low cost, high precision, strong anti-interference ability, and easy installation. Long life, online monitoring and other advantages.

Utility model content

The technical problem to be solved in the utility model is to solve the deficiencies of the existing technology, and propose an on-line monitoring system for the temperature of the cable intermediate joint based on fog computing technology, which has good stability, high temperature measurement accuracy, low cost, easy installation and long service life , easy to use, online monitoring and other advantages.

In order to solve the problems of the technologies described above, the technical solution adopted in the utility model is:

An on-line temperature monitoring system for cable intermediate joints based on fog computing technology, characterized in that it includes several central nodes, several terminal nodes communicatively connected to the central nodes, a GPRS network communicatively connected to all central nodes, and a GPRS network communicatively connected to the GPRS network data management platform;

Each terminal node includes a cable, an intermediate joint on the cable, a temperature sensor, a data acquisition module, a wireless transmission module, and an energy harvesting power management module, and the intermediate joint includes a prefabricated part and a protective shell arranged outside the prefabricated part;

The temperature sensor includes a joint conductor sensor arranged on the conductor of the cable inside the preform, a body conductor sensor arranged on the conductor outside the preform, a body skin sensor arranged on the skin of the cable, and a sensor arranged on the skin of the preform. The joint skin sensor, the protective shell skin sensor set on the protective shell skin, and the ambient temperature sensor set outside the protective shell, all the above temperature sensors are connected to the data acquisition module; the joint conductor sensor is a built-in wireless sensor with a ring structure. Passive temperature sensor, the inner diameter of the ring-type joint conductor sensor is matched with the outer diameter of the cable conductor, and is sleeved on the conductor in the prefabricated part;

The energy harvesting power management module includes an energy harvesting coil and a power management module connected to the energy harvesting coil. The power management module includes a protection circuit, a rectifier filter circuit, an energy harvesting power control circuit and a voltage stabilizing output circuit that are electrically connected in sequence. On the cable, the energy harvesting power control circuit is also connected to the storage battery, and the output end of the protection circuit is also connected to the energy harvesting power control circuit;

The input end of the wireless transmitting module is connected to the data acquisition module, and the output end is connected to the central node.

The further improvement of the technical solution of the utility model is that: the central node includes an energy-taking power supply, a central node module, a data processing module and a GPRS transmitting module connected in sequence, the central node module communicates with the wireless transmitting module of the terminal node, and the GPRS transmitting module Communication connection with data management platform through GPRS network.

The further improvement of the technical solution of the utility model lies in that: the data management platform includes a server with built-in temperature measurement system software, and the server communicates with the GPRS transmitting module of the central node through the GPRS network.

The further improvement of the technical solution of the utility model lies in: it also includes an alarm, and the alarm communicates with the GPRS transmitting module of the central node through the GPRS network.

The further improvement of the technical solution of the utility model lies in that the environment temperature sensor is 0.2m-2m away from the protective shell.

The further improvement of the technical solution of the utility model lies in that: there are two protective shell skin sensors, which are symmetrically arranged at both ends of the protective shell of the intermediate joint.

The further improvement of the technical solution of the utility model lies in that the energy-taking coil is a bayonet structure.

The further improvement of the technical solution of the utility model lies in that: the data acquisition module and the wireless transmission module are ZigBee wireless communication modes.

The further improvement of the technical solution of the utility model lies in that: the central node module also adopts the ZigBee wireless communication mode.

Due to the adoption of the above technical solution, the technical progress of the utility model is: the utility model has the advantages of good stability, high temperature measurement accuracy, low cost, easy installation, long life, convenient use, and online monitoring.

(1) Utilize the ZigBee wireless networking function, integrate the data collector and ZigBee wireless transmission module, and form a temperature acquisition system with small size, reliable communication and low power consumption. In the actual cable laying situation, the space where the data acquisition system can be installed is limited, so the utility model can well adapt to the field environment.

(2) The new fog computing network is used to extend network computing from the center of the network to the edge of the network. This network has the advantages of low latency and location awareness, and at the same time has a wider geographical distribution and greater range of mobility, suitable for multi-node measurements on cable lines. Use ZigBee to transmit data between terminal nodes. When the data is transmitted to the central node, it will be processed and calculated. Finally, the processed data will be transmitted to the server in the data management platform through the GPRS network through the ZigBee to GPRS gateway. The utility model comprehensively utilizes the fog computing network and the cloud computing network, and can be applied in the field of online temperature monitoring of underground cables.

(3) The temperature sensor is installed inside the intermediate joint, and multiple measuring points are distributed in a quasi-distributed form to monitor the internal temperature of the intermediate joint in real time. The internal temperature measurement can find the position of the insulation defect earlier and more accurately, and the temperature measurement is less affected by the environment , which is beneficial to accurately calculate the temperature value of the conductor. In addition, installing the temperature sensor inside the intermediate joint can protect it from water immersion, prolong the service life, and ensure the temperature measurement accuracy.

(4) ZigBee and GPRS combined data transmission mode. ZigBee has the advantages of low power consumption, automatic networking, and free communication in short-distance wireless transmission. It is suitable for forming a wireless sensor network. GPRS basically achieves seamless coverage in cities. Suitable for long-distance wireless transmission, the combination of ZigBee and GPRS, the two complement each other, and can be applied in the field of online temperature monitoring of underground power cables.

(5) The energy harvesting coil is designed as a bayonet type, which can be directly installed on the outside of the cable, which is convenient for on-site installation.

Description of drawings

Fig. 1 is a structural schematic diagram of the overall scheme of the utility model;

Fig. 2 is a structural schematic diagram of a terminal node of the present invention;

Fig. 3 is a circuit schematic diagram of the energy harvesting power management module of the utility model;

Fig. 4 is a schematic diagram of the central node circuit of the present utility model;

Fig. 5 is the temperature measurement system software flowchart in the utility model data management platform;

Among them, 3. Conductor, 4. Cable, 7. Sealant, 9. Data acquisition module, 10. Wireless transmission module, 20. Siren;

31. Energy harvesting power supply, 32. Central node module, 33. Data processing module, 34. GPRS transmitting module;

50. Power management module, 51. Energy harvesting coil, 52. Protection circuit, 53. Rectification and filtering circuit, 54. Energy harvesting power control circuit, 55. Voltage stabilized output circuit, 56. Battery;

61. Protective shell, 62. Prefabricated parts;

T1, connector conductor sensor, T2, body conductor sensor, T3, body skin sensor, T4, joint skin sensor, T5, protective shell skin sensor Ⅰ, T6, protective shell skin sensor Ⅱ, T7, ambient temperature sensor, R1, built-in signal Transceiver antenna.

Detailed ways

Below in conjunction with embodiment the utility model is described in further detail:

Referring to Figures 1 to 5, the terminal nodes are arranged according to Figure 2: each terminal node includes seven temperature sensors, which are respectively: the joint conductor sensor T1 on the conductor 3 in the prefabricated part 62, and the conductor 3 arranged on the cable 4 The body conductor sensor T2 on the cable 4, the body skin sensor T3 arranged on the skin of the cable 4, the joint skin sensor T4 arranged on the skin of the prefabricated part 62, the protective shell skin sensor IT5 and the protection shell symmetrically arranged at both ends of the protective shell 61 skin. The shell skin sensor IIT6 and the ambient temperature sensor T7, wherein the protective shell skin sensor IT5 and the protective shell skin sensor IIT6 are symmetrically arranged at 1/6 and 5/6 of the protective shell 61 of the intermediate joint 6, and the ambient temperature sensor T7 is suspended It is placed one meter away from the protective shell 61 of the intermediate joint, so that multi-point measurement can be realized by installing corresponding temperature sensors on different layers of the cable 4 to improve the test accuracy.

The joint conductor sensor T1 adopts 3MSC123TII joint wireless conductor temperature monitoring equipment, which is a wireless passive sensor. The outer shell of the sensor is made of polytetrafluoroethylene material. After installing the sensor made of this material, it will not affect the internal electric field of the intermediate joint, and will not cause damage inside the intermediate joint. The temperature field changes, and the temperature test accuracy is high. The joint conductor sensor T1 adopts a ring-shaped structure, and its inner diameter matches the outer diameter of the cable conductor. During the installation process of the intermediate joint, the joint conductor sensor T1 is set on the conductor 3 of the cable 4 in the prefabricated part 62 . The outer shell of the connector conductor sensor T1 is smooth and can be used as an insulation extension of the cable 4, and it will not affect the insulation performance of the cable 4 when it is installed inside the intermediate joint of the cable 4. The installation method of this kind of sensor can be built inside the cable intermediate joint without damaging the cable insulation, and directly measure the temperature of the cable intermediate joint conductor. At the same time, because the joint conductor sensor T1 is installed inside the intermediate joint of the cable 4, it can effectively prevent The damage and influence caused by the external environment can make the connector conductor sensor T1 long-term use in various harsh operating environments such as cable tunnels and cable trenches.

Body conductor sensor T2 ~ ambient temperature sensor T7 is mainly used to measure the temperature of other measuring points except the intermediate joint conductor, so as to compare and analyze with the intermediate joint conductor temperature. These six temperature sensors are all DSl8B20 wired temperature sensors, which are single-wire digital temperature sensors. The DS18B20 temperature sensor is an improved intelligent temperature sensor newly launched by DALLAS Semiconductor Corporation of the United States. All conversion elements and conversion circuits are integrated in a triode-shaped In the integrated circuit, the volume is small, and it has outstanding advantages in temperature measurement accuracy, conversion time, transmission distance, resolution, etc. It can directly convert the temperature signal into a digital signal. The superiority of the DS18B20 temperature sensor can connect multiple sensors in parallel. All temperature data is transmitted to the data acquisition module on the root data bus, which is widely used in multi-point temperature measurement and intelligent temperature detection systems.

During the production process of the intermediate joint, the installation of the corresponding temperature sensor is interspersed. The built-in signal transmitting and receiving antenna R1 of the joint conductor sensor T1 is led out of the prefabricated part 62, and the signal lead-out wires of all temperature sensors are drawn out from the glue filling port of the protective shell 61. A sealant 7 such as epoxy resin or polyurethane waterproof resin is poured between the prefabricated part 62 and the protective shell 61 for sealing. Since the epoxy resin or polyurethane waterproof resin has excellent bonding strength and good dielectric properties, the prefabricated part 62 and the The protective shell 61 is tightly sealed as a whole.

The above seven sensors are all communicatively connected to the input end of the data acquisition module 9. The data acquisition module 9 is a highly integrated single-bus multi-point power-driven meter, and performs data communication through a built-in ZigBee wireless module. The temperature measurement speed of the data acquisition module 9 is 4s, the anti-lightning protection is 6.5KV, the protection baud rate is 9600.n.8.1, the communication port is RS485 (based on the MODBUS-RTU communication protocol), the transmission distance of the RS485 bus is 1200m, and the operating environment is -40℃～+85℃. These advantages can ensure the long-term reliable operation of the data acquisition module 9 .

The output end of the data acquisition module 9 is connected with the input end of the ZigBee wireless transmission module 10, and the output end of the ZigBee wireless transmission module 10 is connected with the central node module 32 of the central node. The ZigBee wireless transmission module 10 is used to send the temperature data of each point of the cable intermediate joint collected by the data acquisition module 9 to the central node through relay forwarding. There will be an intermediate connector every 400 meters or so on the power cable line, which requires a considerable transmission distance in the wireless transmission method, and the wireless transmission distance is related to power consumption. Due to the limited energy supply of the energy harvesting coil 51, the function of the wireless transmission method The power consumption cannot be too large, the amount of temperature data is not large, and there is no need for a high transmission rate, and the transmission rate of the wireless transmission method is not high. The utility model selects the ZigBee wireless communication mode for data transmission, and has the characteristics of low power consumption while ensuring the data transmission distance and reliability.

The energy-capturing power management module includes an energy-capturing coil 51 and a power management module 50 connected to the energy-capturing coil 51 , and generates a 12V driving voltage with the current passing through the cable 4 . The power management module 50 includes a protection circuit 52, a rectification and filtering circuit 53, an energy-taking power control circuit 54, and a voltage-stabilizing output circuit 55 connected in sequence. The energy-taking power control circuit 54 is also connected to a lithium storage battery 56, and the output terminal of the protection circuit 52 is also connected to the lithium storage battery 56. It is connected with the power control circuit 54 for energy acquisition; the energy acquisition coil 51 is a bayonet structure and is directly clamped outside the cable 4, and the data acquisition module 9, ZigBee wireless transmission module 10 and power management module 50 can be installed outside or in the middle of the intermediate joint In the newly designed chamber inside the connector. The energy-taking coil 51 is used to convert the magnetic field formed by the current in the cable 4 into a voltage; the protection circuit 52 is used to prevent the impact of the overvoltage on the system caused by the fault short circuit of the cable 4 or the operation of the power system; the rectification filter circuit 53 converts the AC voltage Convert to a DC voltage, and filter the voltage at the same time to reduce the harmonics of the voltage.

The energy harvesting power control circuit 54 is used to monitor the voltage formed by the energy harvesting coil 51. When the power is sufficient, the energy harvesting coil 51 directly supplies energy to the monitoring system formed by the data acquisition module 9 and the ZigBee wireless transmission module 10, and provides energy to the lithium battery 56 charging; when the power is insufficient or there is no power, the data acquisition module 9 and the ZigBee wireless transmission module 10 are powered by the lithium battery 56, which effectively increases the battery life of the power supply and can meet long-term stable and continuous energy supply. The voltage stabilizing output circuit 55 is used for stably outputting 12V voltage. This energy harvesting power management module is suitable for high-voltage transmission lines with voltage levels of 10kV, 35kV, 110kV, 220kV, and 500kV. Stable power supply.

Both the data acquisition module 9 and the ZigBee wireless transmission module 10 are in ZigBee wireless communication mode.

Layout central node according to Fig. 2: each central node comprises energy-taking power supply 31, ZigBee central node module 32, data processing module 33 and GPRS transmitting module 34 connected in sequence, ZigBee central node module 32 and corresponding ZigBee wireless transmitting module 10 Communication connection, the GPRS transmitting module 34 communicates with the data management platform through the GPRS network.

Wherein the data processing module 33 is a single-chip microcomputer with calculation and data analysis functions. When central node work, at first ZigBee central node module 32 adopts the mode of polling to read the terminal node temperature data in its responsible range, then the obtained temperature data is transmitted in the data processing module 33, and in the data processing module 33 The single-chip microcomputer processes the temperature data in the local range through software calculation and analysis. If the temperature data is normal, the data is packaged and uploaded; if the temperature is abnormal, the alarm 20 is used to immediately send an alarm to the dispatch center, and an abnormal data packet is sent to the upper network. The central node transmits data to the upper layer cloud network, and mainly uses the GPRS transmitting module 34 to store the data to the cloud server through the GPRS network. Through such a fog computing network, low-dimensional data processing is placed on the data collection end, and the process of uploading data to the cloud and then feeding the processed information back to the dispatching center from the cloud is eliminated, so that when the intermediate joints are locally overheated, they can be processed as quickly as possible. Send an alarm to the dispatch center in order to adjust the load in time and prevent accidents. At the same time, the cloud can send commands to control the operation of the central node through the siren and the central node, so as to realize the two-way communication between the high-level cloud network and the fog computing network.

The data management platform is used to realize the collection, processing, storage, diagnosis and early warning of temperature data, including a server with built-in temperature measurement system software. The server communicates with the GPRS transmitter module 34 of the central node through the GPRS network. The temperature measurement system software is It is written using LabVIEW software to realize the control of the temperature measurement system and the management of temperature data.

An alarm 20 is also provided, and the alarm 20 is communicatively connected with the GPRS transmitting module 34 of the central node through the GPRS network.

The terminal node is a monitoring unit installed in the middle joint or the key monitoring area. The terminal node forms a ZigBee network through the automatic networking function of the ZigBee wireless transmission module 10. Each terminal node has both the functions of a terminal and a relay, and has a The power management module can ensure long-term operation. The terminal node collects the cable temperature data at its location and uploads it to the central node through relay. The central node is installed in the cable well or at the cable exit, meeting the requirements of GPRS signal transmission and reception. The central node adopts polling mode to read the terminal node temperature data within its responsible range, the data read is processed by the single-chip microcomputer in the data processing module 33, and the processed data is transferred to the GPRS gateway through the GPRS transmitting module 34 using ZigBee , Upload data by GPRS network. If the single-chip microcomputer analysis in the data processing module 33 finds that there is local overheating, then the data is uploaded to the siren 20, and the cable 4 overheating alarm is sent by the siren 20 to the dispatch center, and the data is uploaded to the cloud data management platform for further analysis simultaneously; if the data If it is normal, upload it directly to the cloud data management platform. Fog computing directly analyzes the data at the bottom layer, and can give timely alarms for abnormal situations. In addition, the cloud data management platform can also use the alarm 20 to send instructions to the central node to control the operation of the central node.

ZigBee is a low-complexity, self-organizing, low-power, low-data-rate, low-cost networking wireless standard for controlling and monitoring various systems, supporting multiple network topologies. Devices using ZigBee can operate for at least two years without battery replacement.

Claims (9)

1. A cable intermediate joint temperature online monitoring system based on fog computing technology, characterized in that: it includes several central nodes, some terminal nodes connected by communication with the central nodes, a GPRS network connected by communication with all central nodes, and a communication network with the GPRS network connected data management platform; Each terminal node includes a cable (4), an intermediate joint on the cable (4), a temperature sensor, a data acquisition module (9), a wireless transmission module (10) and an energy harvesting power management module, and the intermediate joint includes a prefabricated part (62 ) and a protective shell (61) arranged outside the prefabricated part (62); The temperature sensor includes a joint conductor sensor (T1) arranged on the conductor (3) of the cable (4) inside the prefabricated part (62), a body conductor sensor (T2) arranged on the conductor (3) outside the prefabricated part (62) ), the body skin sensor (T3) set on the skin of the cable (4), the joint skin sensor (T4) set on the skin of the prefabricated part (62), the protective shell skin set on the skin of the protective shell (61) sensor, the ambient temperature sensor (T7) arranged outside the protective case (61), all of the above temperature sensors are connected to the data acquisition module (9); the connector conductor sensor (T1) is a built-in wireless passive sensor with a ring structure For the temperature sensor, the inner diameter of the ring-shaped connector conductor sensor (T1) matches the outer diameter of the conductor (3) of the cable (4), and is sleeved on the conductor (3) in the prefabricated part (62); The power management module for energy acquisition includes an energy acquisition coil (51) and a power management module (50) connected to the energy acquisition coil (51). The power management module (50) includes a protection circuit (52), a rectification and filtering circuit (53 ), the energy harvesting power control circuit (54) and the voltage-stabilizing output circuit (55), the energy harvesting coil (51) is arranged on the cable (4) and connected with the protection circuit (52) of the power management module (50), and the energy harvesting The power control circuit (54) is also connected to the storage battery (56), and the output terminal of the protection circuit (52) is also connected to the energy-taking power control circuit (54); The input end of the wireless transmission module (10) is connected to the data acquisition module (9), and the output end is connected to the central node. 2. The online monitoring system for cable intermediate joint temperature based on fog computing technology according to claim 1, characterized in that: the central node includes sequentially connected energy-taking power supply (31), central node module (32), data processing The module (33) and the GPRS transmitting module (34), the central node module (32) communicates with the wireless transmitting module (10) of the terminal node, and the GPRS transmitting module (34) communicates with the data management platform through the GPRS network. 3. The cable intermediate joint temperature online monitoring system based on fog computing technology according to claim 1, characterized in that: the data management platform includes a server with built-in temperature measurement system software, and the server communicates with the GPRS of the central node through the GPRS network. The transmitting module (34) is connected for communication. 4. The on-line temperature monitoring system for cable intermediate joints based on fog computing technology according to claim 1, characterized in that: it also includes an alarm (20), and the alarm (20) communicates with the GPRS transmitting module of the central node through the GPRS network ( 34) Communication connection. 5. The online monitoring system for cable intermediate joint temperature based on fog computing technology according to claim 1, characterized in that: the ambient temperature sensor (T7) is 0.2m-2m away from the protective case (61). 6. The on-line temperature monitoring system for cable intermediate joints based on fog computing technology according to claim 1, characterized in that there are two protective shell skin sensors, which are symmetrically arranged at both ends of the protective shell (61) of the intermediate joint. 7. The online monitoring system for the temperature of cable intermediate joints based on fog computing technology according to claim 1, characterized in that: the energy harvesting coil (51) is a bayonet structure. 8. The online monitoring system for the temperature of cable intermediate joints based on fog computing technology according to claim 1, characterized in that: the data acquisition module (9) and the wireless transmission module (10) are both ZigBee wireless communication methods. 9. The online monitoring system for cable intermediate joint temperature based on fog computing technology according to claim 2, characterized in that: the central node module (32) is also ZigBee wireless communication mode.