High-voltage cable on-line temperature measurement system based on encrypted communication

Abstract

The application discloses a kind of high-voltage cable on-line temperature measurement system based on encrypted communication, including RFID label and reader-writer;Wherein, RFID label includes temperature measurement unit, radio frequency unit and label antenna, and temperature measurement unit and label antenna are connected by radio frequency unit;Temperature measurement unit includes temperature measurement chip, electric energy conversion module, anti-collision response module, authentication module and encryption module;Reader-writer includes main control unit, radio frequency unit and reader-writer antenna, and main control unit is connected with reader-writer antenna by radio frequency unit, and main control unit sends radio frequency signal to RFID label and receives label response by radio frequency unit and reader-writer antenna;Main control unit is also connected with dynamic power regulation unit, anti-collision unit, authentication unit, encryption unit, label response decoding unit, data processing unit, data transmission unit;The application adopts wireless passive temperature measurement mode based on RFID, effectively improves measurement accuracy, and simultaneously, adopts encrypted data transmission and two-way identity authentication, guarantees data information safety and reliability.

Description

Technical Field

[0001] This invention belongs to the field of high-voltage cable temperature measurement technology, specifically relating to an online high-voltage cable temperature measurement system based on encrypted communication. Background Technology

[0002] With the increase in electricity demand and the significant growth in the scale of power generation equipment, the transmission channels are becoming increasingly dense, and the risks of facility and equipment management are also increasing sharply. High-voltage cables are an important component of the power transmission system. As the carrier of electrical energy transmission, their stable working state is of great significance for ensuring power supply quality and improving the safety and reliability of the new smart grid. In the process of power transmission, except for a few remote areas where overhead high-voltage cables are used to transmit power, the existing high-voltage cable power transmission is still mainly carried out by underground laying.

[0003] As the service life of cables increases, high-voltage cables laid in underground cable trenches experience temperature rises due to various reasons, such as insulation aging and external damage. Since cables are usually in enclosed environments like cable trenches, temperature rises are not easily detected, which can easily lead to accidents such as cable trench explosions and fires. Furthermore, high-voltage cables are relatively concentrated in cable trenches, and a problem in one section of cable can also affect the normal operation of nearby lines.

[0004] Among them, the conductor temperature of a cable is an important indicator and key parameter for detecting whether the cable is operating well and determining its carrying capacity. It is of great significance for assessing the safety status of the power transmission system and the stable and efficient operation of power cables. Therefore, it is very important to monitor the temperature of high-voltage cables.

[0005] Therefore, in order to solve the above problems, it is necessary to develop a high-voltage cable online temperature measurement system based on encrypted communication. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-voltage cable online temperature measurement system based on encrypted communication. It adopts an RFID-based wireless passive temperature measurement method, which effectively improves the measurement accuracy. At the same time, it uses encrypted data transmission and two-way identity authentication to ensure the security and reliability of data information.

[0007] The objective of this invention is achieved as follows: a high-voltage cable online temperature measurement system based on encrypted communication, comprising multiple RFID tags disposed on the cable side for detecting cable temperature, and a reader adapted to the RFID tags;

[0008] The RFID tag includes a temperature measurement unit, a radio frequency (RF) unit, and a tag antenna, wherein the temperature measurement unit and the tag antenna are connected via the RF unit. The temperature measurement unit includes a temperature measurement chip, a power conversion module, an anti-collision response module, an authentication module, and an encryption module. The temperature measurement chip integrates a digital temperature sensor, an analog-to-digital converter (ADC), and an EPC memory. The digital temperature sensor collects the temperature signal of the cable under test, converts the data through the ADC, and stores it in the EPC memory. The power conversion module converts the received electromagnetic field energy into a DC signal, which powers the RFID tag. The anti-collision response module randomly selects a time slot to return a response signal containing a unique identifier when the reader broadcasts a query command. The authentication module performs two-way authentication with the reader. The encryption module encrypts the stored tag data and completes encryption authentication with the reader. The RF unit includes an RF front-end and an oscillator. The RF unit is connected to the tag antenna and receives electromagnetic fields to generate current through electromagnetic induction for power supply and signal transmission.

[0009] The reader includes a main control unit, a radio frequency unit, and a reader antenna. The main control unit is connected to the reader antenna through the radio frequency unit. The main control unit sends radio frequency signals to the RFID tag and receives tag responses through the radio frequency unit and the reader antenna. The main control unit is also connected to a dynamic power adjustment unit, an anti-collision unit, an authentication unit, an encryption unit, a tag response decoding unit, a data processing unit, and a data transmission unit.

[0010] The system comprises the following components: a dynamic power adjustment unit for dynamically adjusting the reader's transmission power; an anti-collision unit for triggering tag responses via broadcast query commands, whereby the reader dynamically adjusts the frame length and re-polles until tag counting is complete if a collision is detected due to the superposition of multiple tag signals, thus avoiding collisions and improving tag recognition rate; an authentication unit for bidirectional interactive authentication between the reader and RFID tags; an encryption unit for storing the system root key and performing encryption authentication and data encryption / decryption with the RFID tag-side temperature measurement unit; a tag response decoding unit for decoding the received and decrypted RFID tag data to obtain the tag ID and temperature data; a data processing unit for filtering and aggregating the temperature data, eliminating redundant information to form structured data; and a data transmission unit for establishing data transmission connections with the backend application system and database.

[0011] Furthermore, the RFID tag employs a T-type matching network for impedance matching.

[0012] Furthermore, the dynamic power adjustment unit dynamically adjusts the reader's transmission power, specifically including the following steps: ① Setting an initial transmission power and transmitting a command at the initial power node; ② Detecting whether valid detection data is obtained at this power point. If valid detection data is obtained, it is determined that the activation condition is met, and proceeding to step ③; if no valid detection data is obtained, proceeding to step ④; ③ Initiating multiple consecutive detection commands at this power node, and arithmetically averaging the multiple detection data to obtain the final valid detection data; ④ Determining whether the power node has reached the maximum power. If so, the tag is marked as offline; otherwise, the transmission power is increased by 2dBm and the process returns to step ② to continue.

[0013] Furthermore, the anti-collision unit specifically employs an improved dynamic frame slot ALOHA algorithm to achieve anti-collision. By changing the frame length, the number of slots in the next frame is dynamically adjusted, and a comparison database is established statistically for searching and matching during the next identification, thereby shortening the matching time. Specifically, it includes the following steps: Let the number of frame slots be... The number of RFID tags is The probability of a tag occupying a time slot follows a binomial distribution; assuming that the probability of an RFID tag occupying a time slot is equal within a time slot range, then... The probability that the tags are in the same time slot is: The expected value is: ,in, When it is free, When the RFID tag is identified, A collision occurred; after identification, the number of successfully identified time slots was counted. The number of time slots in which the collision occurred is The number of idle time slots is The probability of a collision is: Then we can conclude that when Sometimes: The number of RFID tags is obtained through calculation. Specifically, the reader sends commands and initializes. , , Typical frame length The range of values ​​is After one round of identification, the time slot status is determined. If identification is successful or a collision has occurred, then... , After multiple iterations, a judgment is made. Value, if Then adjust the command, if Then judge ,like Then it ends, if Then, the frame length is adjusted by querying the database until the RFID tag is fully identified.

[0014] Furthermore, in the two-way interactive authentication process between the reader and the RFID tag, the reader first sends a request, and after matching the applicable RFID tag, it collects information. The reader then transmits the collected information to the background database, which processes the transmitted information and feeds it back to the reader. The reader then feeds this information back to the tag, completing the two-way authentication.

[0015] Furthermore, the encryption module on the RFID tag side and the encryption unit on the reader side use the national cryptographic algorithm SM7 to achieve encrypted communication.

[0016] Furthermore, the encryption module on the RFID tag side implements encrypted storage of RFID tag data through an encryption algorithm. The reader collects the encrypted RFID tag data, encrypts the collected data information through the encryption unit, and sends the processed and encrypted data through the data transmission unit.

[0017] Furthermore, the tag response decoding unit includes mixing, filtering and demodulating the received modulated signal, extracting the baseband signal, and decoding it to obtain the tag ID and temperature data.

[0018] Furthermore, the data transmission unit specifically interconnects multiple RFID readers in the same area via an RS485 bus and centrally reports data through a DTU module; or it uses a direct network connection method, including wireless 4G network or wired Ethernet, to achieve data transmission.

[0019] Furthermore, the reader also includes a power conversion module for connecting to a power source and supplying power to other units.

[0020] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0021] (1) By adopting a wireless passive temperature measurement method based on RFID radio frequency identification, the temperature is measured by a temperature measuring chip installed inside the high-voltage cable and attached to the object being measured. The temperature data is collected by a reader and writer. At the same time, the antenna generates current through electromagnetic induction to supply power. No internal power supply is required, the power consumption is low, and wireless transmission is possible, thus realizing non-contact multi-target temperature monitoring.

[0022] (2) By setting a dynamic power adjustment unit, the reader's transmission power can be dynamically adjusted in real time, which improves the stability of signal modulation and reduces the accumulation of temperature conversion error, reduces electromagnetic interference in the environment, improves energy transmission efficiency, optimizes tag reading performance at different distances and angles, and effectively improves the convenience and accuracy of temperature acquisition.

[0023] (3) By setting up an encryption unit and using the national cryptographic SM7 algorithm to encrypt the data, and performing two-way identity authentication between the reader and the RFID tag, the authenticity, integrity and security of information transmission are effectively improved. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the principle of the present invention. Detailed Implementation

[0025] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0026] like Figure 1 As shown, a high-voltage cable online temperature measurement system based on encrypted communication includes multiple RFID tags installed on the cable side for detecting cable temperature, and a reader adapted to the RFID tags.

[0027] The RFID tag includes a temperature measuring unit, a radio frequency (RF) unit, and a tag antenna, wherein the temperature measuring unit and the tag antenna are connected through the RF unit. Specifically, the RF unit includes an RF front-end and an oscillator. The RF unit is connected to the tag antenna and is used to receive electromagnetic fields, generate current through electromagnetic induction to power the signal, and transmit information.

[0028] The temperature measurement unit includes a temperature measurement chip, a power conversion module, an anti-collision response module, an authentication module, and an encryption module. The temperature measurement chip integrates a digital temperature sensor, an analog-to-digital converter circuit, and an EPC memory. The digital temperature sensor is used to collect the temperature signal of the cable under test, and the data is converted by the analog-to-digital converter circuit and then stored in the EPC memory.

[0029] The anti-collision response module is used to randomly select a time slot to return a response signal containing a unique identifier when the reader sends a query command via broadcast.

[0030] The authentication module is used for two-way identity authentication with the reader / writer.

[0031] The power conversion module is used to convert the received electromagnetic field energy into a DC signal, which then powers the RFID tag. Preferably, the tag antenna receives electromagnetic waves in the 860-960MHz frequency band provided by the reader antenna and converts them into DC power through the power conversion module.

[0032] The encryption module is used to encrypt the stored tag data and complete encryption authentication with the reader side.

[0033] Preferably, the RFID tag uses a T-type matching network for impedance matching.

[0034] The reader / writer is used to read and write RFID tag information, control the radio frequency unit to send radio frequency signals to the tag, receive and decode the tag response, and transmit the processed data to the application platform.

[0035] The reader includes a main control unit, a radio frequency unit, and a reader antenna. The main control unit is connected to the reader antenna through the radio frequency unit. The main control unit sends radio frequency signals to the RFID tag and receives tag responses through the radio frequency unit and the reader antenna. The main control unit is also connected to a dynamic power adjustment unit, an anti-collision unit, an authentication unit, an encryption unit, a tag response decoding unit, a data processing unit, and a data transmission unit.

[0036] The dynamic power adjustment unit is used to dynamically adjust the reader's transmission power. Preferably, the dynamic power adjustment unit dynamically adjusts the reader's transmission power by including the following steps: ① setting an initial transmission power and transmitting a command at the initial power node; ② detecting whether valid detection data is obtained at the power point. If valid detection data is obtained, it is determined that the activation condition is met, and proceeds to step ③. If no valid detection data is obtained, it proceeds to step ④; ③ initiating multiple consecutive detection commands at the power node and arithmetically averaging the multiple detection data to obtain the final valid detection data; ④ determining whether the power node has reached the maximum power. If so, the tag is marked as offline. Otherwise, the transmission power is increased by 2dBm and the process returns to step ② to continue.

[0037] The anti-collision unit is used to trigger tag responses through broadcast query commands. If a collision caused by the superposition of multiple tag signals is detected, the reader dynamically adjusts the frame length and re-polles until the tag count is completed, so as to avoid collisions and improve the tag recognition rate.

[0038] Preferably, the anti-collision unit specifically employs an improved dynamic frame slot ALOHA algorithm to achieve anti-collision. By changing the frame length, the number of slots in the next frame is dynamically adjusted, and a comparison database is established statistically for searching and matching during the next identification, thereby shortening the matching time. Specifically, it includes the following steps: Let the number of frame slots be... The number of RFID tags is The probability of a tag occupying a time slot follows a binomial distribution; assuming that the probability of an RFID tag occupying a time slot is equal within a time slot range, then... The probability that the tags are in the same time slot is: The expected value is: ,in, When it is free, When the RFID tag is identified, A collision occurred; after identification, the number of successfully identified time slots was counted. The number of time slots in which the collision occurred is The number of idle time slots is The probability of a collision is: Then we can conclude that when Sometimes: The number of RFID tags is obtained through calculation. .

[0039] Preferably, the reader sends commands and initializes. , , Typical frame length The range of values ​​is After one round of identification, the time slot status is determined. If identification is successful or a collision has occurred, then... , After multiple iterations, a judgment is made. Value, if Then adjust the command, if Then judge ,like Then it ends, if Then, the frame length is adjusted by querying the database until the RFID tag is fully identified.

[0040] The authentication unit is used to perform two-way interactive authentication between the reader and the RFID tag.

[0041] Preferably, in the two-way interactive authentication process between the reader and the RFID tag, the reader first sends a request, and after matching the applicable RFID tag, it collects information. The reader then transmits the collected information to the background database, which processes the transmitted information and feeds it back to the reader. The reader then feeds this information back to the tag, completing the two-way authentication.

[0042] Preferably, the specific steps include: ① When the RFID tag enters the reader's identification range, the reader sends a query message and a secret random number RR generated by the reader to request authentication; ② After receiving the request from the reader, the RFID tag generates a random number RT and calculates... ,in, It is an electronic tag ID; It is a transformation rule function shared by the electronic tag and the back-end application system, and then the RFID tag will... ③ After receiving the data sent by the RFID tag, the reader adds the previously generated random number RR and sends it to the backend application system. ④ After receiving the data sent by the reader, the backend application system checks whether there is a tag ID stored in the database. ,satisfy If yes, then the authentication is successful.

[0043] The encryption unit stores the system root key and performs encryption authentication and data encryption / decryption with the temperature measurement unit on the RFID tag side. Preferably, the encryption module on the RFID tag side and the encryption unit on the reader side use the national cryptographic algorithm SM7 to achieve encrypted communication. Preferably, the encryption module on the RFID tag side uses an encryption algorithm to achieve encrypted storage of RFID tag data. The reader collects the encrypted RFID tag data, encrypts the collected data information through the encryption unit, and sends the processed and encrypted data through the data transmission unit.

[0044] The tag response decoding unit is used to decode the received and decrypted RFID tag data to obtain the tag ID and temperature data. Preferably, the tag response decoding unit includes mixing, filtering and demodulating the received modulation signal, extracting the baseband signal, and decoding it to obtain the tag ID and temperature data.

[0045] The data processing unit is used to filter and aggregate temperature data, eliminating redundant information to form structured data.

[0046] The data transmission unit is used to establish a data transmission connection with the background application system and the database. Preferably, the data transmission unit interconnects multiple RFID readers in the same area via an RS485 bus and centrally reports data through a DTU module; or it can use a direct network connection method, including a wireless 4G network or a wired Ethernet, to achieve data transmission.

[0047] Preferably, the reader further includes a power conversion module for connecting to a power source and supplying power to other units.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A high-voltage cable online temperature measurement system based on encrypted communication, characterized in that: This includes multiple RFID tags installed on the cable side for detecting cable temperature, and readers adapted to the RFID tags; The RFID tag includes a temperature measurement unit, a radio frequency (RF) unit, and a tag antenna, wherein the temperature measurement unit and the tag antenna are connected via the RF unit. The temperature measurement unit includes a temperature measurement chip, a power conversion module, an anti-collision response module, an authentication module, and an encryption module. The temperature measurement chip integrates a digital temperature sensor, an analog-to-digital converter (ADC), and an EPC memory. The digital temperature sensor collects the temperature signal of the cable under test, converts the data through the ADC, and stores it in the EPC memory. The power conversion module converts the received electromagnetic field energy into a DC signal, which powers the RFID tag. The anti-collision response module randomly selects a time slot to return a response signal containing a unique identifier when the reader broadcasts a query command. The authentication module performs two-way authentication with the reader. The encryption module encrypts the stored tag data and completes encryption authentication with the reader. The RF unit includes an RF front-end and an oscillator. The RF unit is connected to the tag antenna and receives electromagnetic fields to generate current through electromagnetic induction for power supply and signal transmission. The reader includes a main control unit, a radio frequency unit, and a reader antenna. The main control unit is connected to the reader antenna through the radio frequency unit. The main control unit sends radio frequency signals to the RFID tag and receives tag responses through the radio frequency unit and the reader antenna. The main control unit is also connected to a dynamic power adjustment unit, an anti-collision unit, an authentication unit, an encryption unit, a tag response decoding unit, a data processing unit, and a data transmission unit. The system comprises the following components: a dynamic power adjustment unit for dynamically adjusting the reader's transmission power; an anti-collision unit for triggering tag responses via broadcast query commands, whereby the reader dynamically adjusts the frame length and re-polles until tag counting is complete if a collision is detected due to the superposition of multiple tag signals, thus avoiding collisions and improving tag recognition rate; an authentication unit for bidirectional interactive authentication between the reader and RFID tags; an encryption unit for storing the system root key and performing encryption authentication and data encryption / decryption with the RFID tag-side temperature measurement unit; a tag response decoding unit for decoding the received and decrypted RFID tag data to obtain the tag ID and temperature data; a data processing unit for filtering and aggregating the temperature data, eliminating redundant information to form structured data; and a data transmission unit for establishing data transmission connections with the backend application system and database.

2. The online temperature measurement system for high-voltage cables based on encrypted communication according to claim 1, characterized in that: The RFID tag uses a T-type matching network for impedance matching.

3. The online temperature measurement system for high-voltage cables based on encrypted communication according to claim 1, characterized in that: The dynamic power adjustment unit dynamically adjusts the reader's transmission power, specifically including the following steps: ① Set an initial transmission power and transmit a command at the initial power node; ② Detect whether valid detection data is obtained at this power point. If valid detection data is obtained, it is determined that the activation condition is met, and proceed to step ③. If no valid detection data is obtained, proceed to step ④; ③ Initiate multiple consecutive detection commands at this power node, and perform an arithmetic average of the multiple detection data to obtain the final valid detection data; ④ Determine whether the power node has reached the maximum power. If so, mark the tag as offline. Otherwise, increase the transmission power by 2dBm and return to step ② to continue.

4. The online temperature measurement system for high-voltage cables based on encrypted communication according to claim 1, characterized in that: The anti-collision unit specifically adopts an improved dynamic frame slot ALOHA algorithm to achieve anti-collision. By changing the frame length, the number of slots in the next frame is dynamically adjusted, and a comparison library is established through statistics. During the next identification, a search and matching is performed, thereby shortening the matching time. Specifically, the steps include: setting the number of frame time slots to... The number of RFID tags is The probability of a tag occupying a time slot follows a binomial distribution; assuming that the probability of an RFID tag occupying a time slot is equal within a time slot range, then... The probability that the tags are in the same time slot is: The expected value is: ,in, When it is free, When the RFID tag is identified, A collision occurred; after identification, the number of successfully identified time slots was counted. The number of time slots in which the collision occurred is The number of idle time slots is The probability of a collision is: Then we can conclude that when Sometimes: The number of RFID tags is obtained through calculation. Specifically, the reader sends commands and initializes. , , Typical frame length The range of values ​​is After one round of identification, the time slot status is determined. If identification is successful or a collision has occurred, then... , After multiple iterations, a judgment is made. Value, if Then adjust the command, if Then judge ,like Then it ends, if Then, the frame length is adjusted by querying the database until the RFID tag is fully identified.

5. The online temperature measurement system for high-voltage cables based on encrypted communication according to claim 1, characterized in that: In the two-way interactive authentication process between the reader and the RFID tag, the reader first sends a request, and after matching the applicable RFID tag, it collects information. The reader then transmits the collected information to the background database. The background database processes the transmitted information and feeds it back to the reader. The reader then feeds this information back to the tag, completing the two-way authentication.

6. The online temperature measurement system for high-voltage cables based on encrypted communication according to claim 1, characterized in that: The encryption module on the RFID tag side and the encryption unit on the reader side use the national cryptographic algorithm SM7 to achieve encrypted communication.

7. The online temperature measurement system for high-voltage cables based on encrypted communication according to claim 1, characterized in that: The encryption module on the RFID tag side uses an encryption algorithm to encrypt and store RFID tag data. The reader collects the encrypted RFID tag data, encrypts the collected data information through the encryption unit, and sends the processed and encrypted data through the data transmission unit.

8. The online temperature measurement system for high-voltage cables based on encrypted communication according to claim 1, characterized in that: The tag response decoding unit includes mixing, filtering and demodulating the received modulated signal, extracting the baseband signal, and decoding it to obtain the tag ID and temperature data.

9. The online temperature measurement system for high-voltage cables based on encrypted communication according to claim 1, characterized in that: The data transmission unit specifically interconnects multiple RFID readers in the same area via an RS485 bus and centrally reports data through a DTU module; or it uses a direct network connection method, including wireless 4G network or wired Ethernet, to achieve data transmission.

10. The online temperature measurement system for high-voltage cables based on encrypted communication according to claim 1, characterized in that: The reader also includes a power conversion module for connecting to a power source and supplying power to other units.

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