Intelligent short-circuit grounding device with high-precision positioning function

Abstract

The invention relates to an intelligent short-circuit grounding device with a high-precision positioning function, the device is used for information transmission and positioning in a transformer substation, the device performs electromagnetic field simulation for a LoRa base station signal coverage field, and on the basis of a LoRa positioning result, an RFID antenna is additionally arranged based on the constraint of an operation key area, so that the positioning accuracy of the transformer substation is improved. The method comprises the following steps: acquiring an electromagnetic field simulation result of a base station, reading an RFID tag on equipment, positioning the device according to a signal acquired from the RFID tag, optimizing layout parameters of the base station according to the acquired signal, and updating the electromagnetic field simulation result according to the optimized layout. By adopting the device disclosed by the invention, the security and reliability of information processing are ensured through encryption communication, and meanwhile, the positioning precision in a dynamic environment is improved due to online updating of an electromagnetic field simulation result.

Description

Technical Field

[0001] The invention belongs to the field of intelligent positioning, and in particular relates to an intelligent short-circuit grounding device with a high-precision positioning function. Background Art

[0002] Power operation safety is the premise and focus of daily work. In order to ensure the safety of construction operations and avoid safety accidents such as going to the wrong interval, it is urgent to perform sub-meter positioning of operators and operating equipment. The indoor environment of the substation is complex, and the distribution cabinets and substation equipment are all made of metal. There is serious multipath interference, which makes it difficult to achieve sub-meter high-precision positioning. The positioning error of the mainstream LoRa positioning solution on the market is 50-200m (reference: LE Marquez and M. Calle, "Understanding LoRa-based Localization: Foundations and Challenges," in IEEE Internet of Things Journal, doi: 10.1109 / JIOT.2023.3248860.), which is mainly used for cell-level positioning of LoRa nodes, which is far lower than the sub-meter positioning required for power operations, and it is even more difficult to meet the decimeter positioning requirements of key operation areas.

[0003] At the same time, the power supply safety inside the substation involves the need to ensure that the positioning technology has a high degree of security. However, the existing indoor positioning technology is difficult to achieve positioning accuracy and data security that meet operational requirements in this environment. Summary of the invention

[0004] In view of the defects existing in the prior art, the purpose of the present invention is to provide an intelligent short-circuit grounding device with high-precision positioning function. By arranging Lora base stations in substations, based on NRSEC3000 encrypted communication and gateway access, a secure information transmission chain is built to transmit various information of the intelligent short-circuit grounding device from the substation to the power grid intranet and the five-defense platform, ensuring the security and reliability of information processing, while being compatible with the existing data security system of the power grid. On the risk control platform, information such as the use location, use status, equipment status, and users of the intelligent short-circuit grounding device can be seen, which ensures effective supervision by supervisors while taking into account the intuitiveness of information display; on the five-defense platform, the use location of the grounding wire, the ABC three-phase hanging status, and the ground card status can be used as the basis for the operation process, effectively avoiding safety issues such as hanging the wrong interval, missing hanging, or equipment falling off.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: an intelligent short-circuit grounding device with a high-precision positioning function, the device is used for information transmission and positioning in a substation, the device performs electromagnetic field simulation on the LoRa base station signal coverage field, and on the basis of the LoRa positioning results, an RFID antenna is additionally arranged based on the constraints of the key operation areas to read the RFID tags on the equipment, the device is positioned according to the signals collected from the RFID tags, and the layout parameters of the base station are optimized according to the collected signals, and the electromagnetic field simulation results are updated according to the optimized layout.

[0006] The substation used for the intelligent short-circuit grounding device includes an Internet of Things platform, a five-defense platform, and a positioning processing module.

[0007] The intelligent short-circuit grounding device can upload data to the security gateway, upload the positioning node data to the base station through an encryption algorithm, and strictly follow the grid intranet access process. After hardware encryption, it is uploaded to the security gateway. The data can be transmitted to the property management platform and the five-defense platform to achieve full-process operation data management and control.

[0008] The risk control platform described in the intelligent short-circuit grounding device can display information such as the usage location, usage status, equipment status, and users of the intelligent short-circuit base device, while ensuring effective supervision by supervisors and taking into account the intuitiveness of information display.

[0009] The five-protection platform described in the intelligent short-circuit grounding device takes the grounding wire usage position, ABC three-phase hanging status, and ground card status as the basis for the operation process, effectively avoiding safety problems such as wrong hanging intervals, missing hanging or equipment falling off.

[0010] Furthermore, the device uses a finite element analysis method to analyze the electromagnetic environment and radio frequency signal compatibility inside the substation, marks key operation areas, and optimizes the layout parameters of the base station through a genetic algorithm.

[0011] Furthermore, the layout parameters of the base stations include the number, location and orientation of the base stations.

[0012] Furthermore, the key operation area is an equipment-intensive area.

[0013] Furthermore, the key operation area includes a power distribution cabinet.

[0014] Furthermore, the device uses the RFID phase signal as the RFID positioning reference.

[0015] Furthermore, the RFID antenna collects observation data of the RFID tag to be located at different positions.

[0016] Furthermore, a virtual antenna array formed by moving antennas is used to form a synthetic aperture to complete the collection of phase information.

[0017] Furthermore, multiple stationary antennas are installed and arranged in the environment to collect observation data from the RFID tags to be located.

[0018] Furthermore, a detailed electromagnetic environment survey of the substation is conducted and the key operation areas of the substation are delineated according to the functional division of different areas of the substation.

[0019] The beneficial technical effect of the present invention is that the intelligent short-circuit grounding device with high-precision positioning function disclosed by the present invention can ensure the security and reliability of information processing, and is compatible with the existing data security system of the power grid. Based on the online update of the offline fingerprint library-environmental node, it is integrated with the ultra-high precision of the LoRa node-RFID asset positioning tag in the key operation area, and the reference nodes are arranged in the environment to realize the online update of the fingerprint library, thereby improving the positioning accuracy in a dynamic environment. It realizes sub-meter positioning in complex indoor environments, and realizes ultra-high precision positioning at the decimeter level in key operation areas, which effectively guarantees the safety of operations in key areas.

[0020] Aiming at the internal environment of the substation, the base station layout is optimized. The electromagnetic environment and radio frequency signal compatibility inside the substation are analyzed by finite element analysis method, and the key operation areas are marked. The number, location, orientation and other parameters of the base stations are optimized by genetic algorithm to achieve a balance between construction cost and positioning accuracy. To ensure data security, the positioning node data is encrypted by encryption algorithm and uploaded to the base station. In strict accordance with the grid intranet access process, it is uploaded to the security gateway after hardware encryption. The data can be transmitted to the property management platform and the five-defense platform to achieve full-process operation data management and control. Based on the high-precision LoRa positioning method of offline fingerprint library-environment node online update, reference nodes are arranged in the environment to realize online update of the fingerprint library, which improves the positioning accuracy in dynamic environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the high-precision positioning process based on the LoRa offline-online fusion fingerprint library and RFID key points;

[0022] Figure 2 It is the online monitoring of environmental reference nodes and the real-time dynamic adjustment diagram of the fingerprint library;

[0023] Figure 3 It is the RFID synthetic aperture positioning map;

[0024] Figure 4 This is a simulation diagram of the LoRa base station layout for a strong radiation complex metal environment;

[0025] Figure 5 It is an optimal antenna arrangement scheme based on genetic algorithm;

[0026] Figure 6 is a schematic diagram of the access solution structure;

[0027] Figure 7 It is a flowchart of encrypted communication;

[0028] Figure 8 It is a schematic diagram of a three-dimensional visualization interface;

[0029] Fig. 9 It is the fluctuation of RSS in LoRawan that classifies all RSS values ​​into two states, so that the classification result of RSS can be expressed as a Bernoulli random variable with time-varying probability. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0031] Embodiment 1

[0032] like Figure 1 As shown, an embodiment of the present invention provides an intelligent short-circuit grounding device with high-precision positioning function, the device includes a positioning processing module, which optimizes the layout of base stations according to the internal environment of the substation, uses the finite element analysis method to analyze the electromagnetic environment and radio frequency signal compatibility inside the substation, marks key operation areas, and optimizes the number, location, orientation and other parameters of the base station through genetic algorithms to achieve a balance between construction cost and positioning accuracy. To ensure data security, the positioning node data is encrypted using an encryption algorithm and uploaded to the base station, and is uploaded to the security gateway after hardware encryption in strict accordance with the grid intranet access process. The data can be transmitted to the property management platform and the five-defense platform to achieve full-process operation data management and control.

[0033] The device is based on an offline fingerprint library-environment node online update high-precision LoRa positioning method, and at the same time, reference nodes are arranged in the environment to realize online update of the fingerprint library, thereby improving the positioning accuracy in a dynamic environment. However, the substation environment is a dynamic, metal-rich positioning environment, and the impact on the positioning method based on a pure offline fingerprint library cannot be ignored. Therefore, in order to further ensure the reliability of positioning accuracy, a dynamic fingerprint library adjustment strategy based on environmental reference nodes is proposed to dynamically adjust the fingerprint library in real time. Reference tags are arranged at key nodes in the environment, and their positions are calibrated, and the initial ERSS values ​​of the reference tags are recorded in the ERSS fingerprint library. The RSS measurement value of the environmental node is uploaded to the server in real time, the ERSS value is calculated in the server, and compared with the initial ERSS value of the environmental node in real time. When the ERSS change exceeds a certain threshold, a local node fingerprint library update process is started. The fingerprint library update uses the Kalman filter algorithm and the Gaussian smoothing algorithm to smooth the fingerprint library results of the adjacent positions after the local LoRa node measurement value changes, so as to use limited environmental reference nodes to predict the online fingerprint library changes in a larger range. The accuracy of fingerprint library updates can be improved and the number of environmental reference node arrangements can be reduced.

[0034] Due to the complexity of radio propagation, the RSS (Received Signal Strength) distribution in indoor environments is difficult to model and fit into a known distribution. This is especially true in power distribution rooms where metal interference is more obvious and multipath effects are more serious. Figure 2 As shown in Figure 2, the complexity of radio propagation makes it difficult to predict RSS values. To overcome this challenge and further quantify RSS fluctuations, ERSS (Extreme RSS) is used to build an RSS fingerprint library.

[0035] The ultra-high precision fusion positioning method of LoRa nodes and RFID asset positioning tags in key operation areas is adopted to achieve ultra-high precision positioning of key areas, which effectively ensures the operation safety in key areas.

[0036] For equipment-intensive areas such as power distribution cabinets, high-precision positioning is required to assist the positioning area corresponding to the construction point. RFID tags commonly used in power grid equipment management are used to assist high-precision positioning. Based on the LoRa positioning results, RFID antennas are arranged based on the constraints of key operation areas to read the RFID tags on the equipment. Taking into account the regional directional reading characteristics of RFID and the influence of a large amount of metal interference in the real environment, the RFID phase signal is used as the RFID positioning reference, which can improve the signal high resolution and have a certain ability to resist multipath interference.

[0037] Considering the distance and direction ambiguity of the phase, the device correlation of the phase offset, etc., the information collected by a single stationary RFID antenna cannot realize the spatial position identification of the RFID tag. Therefore, the RFID antenna collects observation data of the RFID tag to be located at different positions to increase the amount of data available for positioning.

[0038] In an optional implementation, multiple stationary antennas are installed and arranged in the environment. This is simple, direct and easy to implement, but has high cost, small positioning range and weak scalability.

[0039] In another optional implementation, a virtual antenna array formed by moving antennas is used to form a synthetic aperture to complete the collection of phase information.

[0040] like Figure 3 As shown, under synthetic aperture sampling, the phase observation sequence can be obtained i=1,2,3,...N, where θ (i) is the phase information observed when the tag is read for the i-th time, is the spatial position information of the RFID antenna Ai when the tag is read for the i-th time. Synthetic aperture allows the RFID antenna to collect information from multiple different continuous positions, and the amount of data used for positioning is relatively rich, so its positioning accuracy is often higher.

[0041] The basic principle of RFID synthetic aperture positioning is to compare the matching degree of the collected phase sequence information with the theoretical phase sequence of each possible spatial position. At the real tag position, its theoretical phase sequence is most matched with the collected phase sequence information. On the contrary, at a position that is not the real tag position, the matching degree between its theoretical phase sequence and the collected phase sequence information will decrease. Therefore, constructing a matching degree evaluation function between the collected phase sequence information and the theoretical phase sequence of each possible position is the key to the synthetic aperture positioning method.

[0042] In order to accurately locate the RFID tag in three-dimensional space, multiple antennas are used to perform phase observation sampling on the same tag. The disentangled phase-position model under multiple antennas is:

[0043]

[0044] In the formula, the subscript k represents the corresponding physical quantity of the kth reader antenna. Similarly, the cost function of RFID tag position recognition based on the multi-antenna disentangled phase-position model is established as follows:

[0045]

[0046] Where M represents the number of reader antennas used for positioning, represents the number of phase observations of k reader antennas, is the i-th unwrapped phase value of the k-th reader antenna, and is the three-dimensional spatial coordinate of the reader antenna corresponding to the i-th phase observation value of the k-th reader antenna.

[0047] The base station layout optimization scheme is based on the RF signal characteristics of the substation environment and the constraints of the key operation areas, including the LoRa base station signal coverage field simulation under the multi-metal strong radiation environment in the substation and the cost-precision balance base station layout optimization scheme based on the genetic algorithm to ensure the positioning accuracy of the key operation areas.

[0048] Among them, when simulating the signal coverage of LoRa base stations in a multi-metal strong radiation environment in a substation, there are multiple metal materials such as walls, cables, distribution cabinets, transformers, etc. in the substation, and there is strong power frequency interference, which has a serious adverse effect on LoRa positioning and communication. At the same time, the layout of base stations needs to be reduced in non-operating areas such as corridors to reduce system energy consumption and save construction and operation and maintenance costs. The finite element method is used to simulate the electromagnetic field inside the substation, clarify the coupling operation mechanism of different base station layout schemes and the environment, and clarify the quantitative impact of base station layout on positioning and communication quality. Figure 4 As shown, through simulation calculation using the finite element method, the distribution of the electromagnetic field inside the substation is obtained, and the feasibility and advantages and disadvantages of different base station layout schemes are evaluated.

[0049] In the cost-precision balanced base station layout optimization plan based on genetic algorithm to ensure positioning accuracy in key operation areas, according to the actual needs of key equipment, cable lines, and personnel operation paths and scopes, the corresponding equipment is used to conduct detailed electromagnetic environment exploration of the substation and delineate the key operation areas of the substation according to the functional division of different areas of the substation. The genetic algorithm is used to construct a substation base station layout plan template based on the actual exploration results of the substation electromagnetic environment. Then, according to the optimization goals of the substation communication base station, the digital twin method is used to virtually deduce the cost of substation base station deployment, and the genetic algorithm is used to optimize the base station deployment template in the key operation area. Under the premise of ensuring positioning accuracy, the deployment parameters and networking topology of the base station are calculated and optimized. A cost-precision balanced base station topology construction and deployment plan is achieved under the premise of ensuring positioning accuracy in key operation areas. Figure 5 As shown in the figure, the rapid digital simulation capability of digital twins is fully utilized to greatly improve the optimization level of the previous scheme. At the same time, the screening characteristics of genetic algorithms in the rapid iteration process of design schemes are fully utilized to optimize the probability-based global optimal layout scheme in a relatively short time.

[0050] In the power grid intranet access solution based on NRSEC3000 hardware encryption, an access solution is built between the positioning processing module and the power grid intranet based on a security gateway for data exchange between the positioning processing module and the intranet.

[0051] like Figure 6 As shown in the figure, the access solution is mainly divided into two parts: firewall and secure access gateway. After obtaining and processing the location information of the device with the certificate, the positioning processing module uploads it to the interface firewall. After the dedicated encryption chip performs hardware encryption on the information through the encryption algorithm, it is parsed and transmitted to the IoT platform and the five-defense platform of the intranet through the secure access gateway, and finally the data is connected to the IoT platform and the five-defense platform. The acquisition of location information and security information and the background management based on the five-defense platform are carried out through the management channel protected by the data isolation component. The access solution introduces a dedicated security chip and a secure access gateway that provide encryption support, while ensuring the data security of the location information transmission between the positioning processing module and the intranet and the management security of the maintenance personnel. At the same time, the access solution provides software and hardware interfaces for the intranet end, which can achieve good compatibility at a low access cost.

[0052] like Figure 7 As shown in the figure, the LoRa wireless radio frequency security system based on encryption algorithm uses the encryption communication scheme based on LoRa to establish an encrypted communication connection between the user equipment and the base station. Under this communication network, the LoRa radio frequency signal of the user equipment is encrypted by the encryption algorithm that meets the requirements of the power grid, and the communication link between the device and the base station is established through the LoRa radio frequency network. The base station uses this secure communication link to fuse and solve the location information of the device according to multiple parameters of the radio frequency signal, and realizes data communication networking. The LoRa network is a mature communication standard with the characteristics of low power consumption, long distance, and multi-device access. It can realize ultra-long-distance secure channel transmission. Compared with the communication distance of several meters of traditional Wi-Fi and Bluetooth wireless communication technologies, it can realize encrypted secure communication of hundreds of meters on the basis of low power consumption, and the data communication performance and security performance far exceed traditional communication technologies. The communication network composed of the LoRa base station network built based on the above characteristics retains the above advantages, and can provide a complete communication infrastructure support for the ultra-low power consumption and ultra-long battery life operation of the equipment. According to theoretical calculations, a single button battery can provide the power required for one year of operation.

[0053] In addition, the base stations of the communication network adopt the POE power supply solution, which highly integrates the data bus and the communication network DC bus. While ensuring the reliability of wiring, it minimizes the difficulty and physical limitations of wiring, greatly reduces the cost of installation and operation, and improves the convenience of deployment. The communication between base stations adopts a specially developed data bus switch system, which realizes the functions of simultaneous access of a large number of base stations, high-throughput transmission of massive data, and ultra-low communication delay while ensuring security. It ensures the security, reliability and superior performance of the communication network constructed when the number of base stations is large.

[0054] The invention discloses a high-precision visual indoor positioning system corresponding to an intelligent short-circuit grounding device with high-precision positioning function. Figure 8 shown.

[0055] The terminal control system integrated with the positioning processing module can display the real-life digital twin image modeled by 3D, and intuitively display the location of the user's equipment, with good visualization effects. The user rights management system can be integrated into the terminal control system to ensure the security of operation and maintenance management. At the same time, the system has an interactive and easy-to-operate user interface, which is convenient for staff to obtain different types of information and improves the convenience of daily operation and maintenance management.

[0056] like Fig. 9 As shown, the fluctuation of RSS in LoRawan divides all RSS values ​​into two states, so that the classification result of RSS can be expressed as a Bernoulli random variable with time-varying probability.

[0057] It can be seen from the above embodiments that the intelligent short-circuit grounding device with high-precision positioning function disclosed by the present invention ensures the security and reliability of information processing by performing encrypted communication. At the same time, due to the online update of the electromagnetic field simulation results, the positioning accuracy in a dynamic environment is improved.

[0058] The device described in the present invention is not limited to the embodiments described in the specific implementation manner. Those skilled in the art may derive other implementation manners based on the technical solution of the present invention, which also fall within the technical innovation scope of the present invention.

Claims

1. An intelligent short-circuit grounding device with high-precision positioning function, characterized in that: The device is used for information transmission and positioning in a substation. The device performs electromagnetic field simulation on the LoRa base station signal coverage field. On the basis of the LoRa positioning result, an RFID antenna is additionally arranged based on the constraints of the key operation area to read the RFID tag on the device. The device is positioned according to the signal collected from the RFID tag, and the layout parameters of the base station are optimized according to the collected signal. The electromagnetic field simulation result is updated according to the optimized layout.

2. The intelligent short-circuit grounding device with high-precision positioning function as claimed in claim 1, characterized in that: The device uses a finite element analysis method to analyze the electromagnetic environment and radio frequency signal compatibility inside the substation, marks key operation areas, and optimizes the layout parameters of the base station through a genetic algorithm.

3. The intelligent short-circuit grounding device with high-precision positioning function as claimed in claim 2, characterized in that: The layout parameters of the base stations include the number, location and orientation of the base stations.

4. The intelligent short-circuit grounding device with high-precision positioning function as claimed in claim 2, characterized in that: The key operation area is an equipment-intensive area.

5. The intelligent short-circuit grounding device with high-precision positioning function as claimed in claim 4, characterized in that: The key operation area includes the power distribution cabinet.

6. The intelligent short-circuit grounding device with high-precision positioning function as claimed in claim 1, characterized in that: The device uses the RFID phase signal as the RFID positioning reference.

7. An intelligent short-circuit grounding device with high-precision positioning function as claimed in claim 6, characterized in that: The RFID antenna collects observation data of the RFID tag to be located at different positions.

8. The intelligent short-circuit grounding device with high-precision positioning function as claimed in claim 7, characterized in that: A virtual antenna array composed of moving antennas forms a synthetic aperture to complete the collection of phase information.

9. The intelligent short-circuit grounding device with high-precision positioning function as claimed in claim 6, characterized in that: Multiple stationary antennas are installed and arranged in the environment to collect observation data from the RFID tags to be located.

10. The intelligent short-circuit grounding device with high-precision positioning function as claimed in claim 1, characterized in that: Through detailed electromagnetic environment survey of the substation and demarcation of key operation areas of the substation according to the functional division of different areas of the substation.

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