A remote calibration system and method for medium-voltage instrument transformers

Abstract

This invention relates to the field of remote verification technology, specifically to a remote off-site verification system and method for medium-voltage instrument transformers. The system includes a remote control terminal deployed in a different location and a local equipment terminal. The remote control terminal is used to issue verification tasks to the local equipment terminal and receive verification results from the local equipment terminal. The local equipment terminal is used to perform remote off-site verification of the medium-voltage instrument transformers based on the received verification tasks. The local equipment terminal includes a storage area, a transfer area, a verification area, and a monitoring area. The storage area integrates intelligent storage racks to store medium-voltage instrument transformers. The verification area integrates an automatic electrical wiring device and a verification device. The automatic electrical wiring device enables automatic electrical connection between the medium-voltage instrument transformer and the verification device, and the verification device then verifies the medium-voltage instrument transformer and sends the verification results to the remote control terminal. This achieves remote off-site verification of medium-voltage instrument transformers, reduces the cost of sending them for verification, and improves verification efficiency.

Description

Technical Field

[0001] This invention relates to the field of remote calibration technology, specifically to a remote off-site calibration system and method for medium-voltage instrument transformers. Background Technology

[0002] Medium-voltage instrument transformers used for trade settlement are core equipment for power system energy metering and safe power supply. They are mandatory national verification metrological instruments, and their measurement accuracy directly affects the fairness of power trade settlement. According to relevant national metrological regulations, they must be verified by a nationally authorized or statutory metrological laboratory before being put into operation. Currently, due to limitations in metrological authorization qualifications and professional personnel, the verification of medium-voltage instrument transformers can only be carried out at the municipal-level power supply company metrology centers. Instrument transformer users in counties, townships, and remote areas must transport the transformers to be installed to a specialized authorized metrological laboratory for verification before retrieving them for installation.

[0003] This traditional verification model has several prominent problems: First, transportation costs are high and efficiency is low. Rural users are often far away, and transporting transformers back and forth not only incurs high logistics costs but also consumes a lot of time, seriously affecting the user's installation progress. Second, verification service coverage is insufficient. Users in remote areas find it inconvenient to send transformers for verification, making it difficult to meet the national demand for rapid verification of medium-voltage transformers for trade settlement. Third, there is a high degree of reliance on manual labor. In the existing verification process, transformer transfer, wiring, parameter adjustment, and data recording rely heavily on manual operation. This is prone to human error due to differences in personnel qualifications and operator fatigue, affecting the accuracy of the verification results. In other words, the traditional verification model lacks remote verification capabilities and suffers from technical problems such as difficulty in sending transformers for verification and low verification efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a remote off-site calibration system and method for medium-voltage instrument transformers, which realizes remote off-site calibration of medium-voltage instrument transformers, reduces the cost of sending them for calibration, improves the calibration efficiency, and overcomes the technical problems of difficult delivery for calibration and low calibration efficiency.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This invention provides a remote off-site calibration system for medium-voltage instrument transformers, characterized by comprising a remotely deployed remote control terminal and a local equipment terminal; the remote control terminal is used to issue calibration tasks to the local equipment terminal and receive calibration results from the local equipment terminal; the local equipment terminal is used to perform remote off-site calibration of the medium-voltage instrument transformers based on the received calibration tasks; the local equipment terminal includes a storage area, a transfer area, a calibration area, and a monitoring area; the storage area integrates intelligent storage racks for storing medium-voltage instrument transformers; the transfer area integrates a conveyor line for transferring medium-voltage instrument transformers between the storage area and the calibration area; the calibration area integrates an automatic electrical wiring device and a calibration device, which automatically connects the medium-voltage instrument transformers and the calibration device, thereby calibrating the medium-voltage instrument transformers and sending the calibration results to the remote control terminal; the monitoring area integrates an environmental monitoring device for monitoring the calibration process of the medium-voltage instrument transformers.

[0006] Optionally, the intelligent warehouse racking includes racks to be inspected, racks that have passed inspection, and racks that have failed inspection. The storage area also integrates stacking AGVs. The stacking AGVs perform outbound operations for racks to be inspected based on the inspection tasks issued by the remote control terminal, perform inbound operations for racks that have passed inspection based on the inspection results of the inspection device, and perform inbound operations for racks that have failed inspection based on the inspection results of the inspection device.

[0007] Optionally, the storage area also integrates a tooling pallet for supporting medium-voltage transformers. The stacking AGV is equipped with a laser navigation module and a bidirectional extension arm. The laser navigation module is used to navigate and position the tooling pallet, and the bidirectional extension arm is used to lift and place the tooling pallet. The upper part of the tooling pallet is provided with a first positioning groove for fixing the medium-voltage transformer, and the bottom of the tooling pallet is provided with a second positioning groove that is adapted to engage with the roller conveyor assembly of the conveyor line and the bidirectional extension arm of the stacking AGV. The edges of the tooling pallet are provided with cushioning rubber pads for buffering the impact of the transfer.

[0008] Optionally, the verification tasks include insulation resistance, power frequency voltage, and error measurement; the verification equipment includes an insulation resistance tester for measuring insulation resistance, a withstand voltage test device for measuring power frequency voltage, a voltage transformer error test device, and a current transformer error test device for measuring errors.

[0009] Optionally, the automatic electrical wiring device includes a voltage transformer primary terminal wiring device, a voltage transformer secondary terminal wiring device, a current transformer primary terminal wiring device, and a current transformer secondary terminal wiring device. The voltage transformer primary terminal wiring device is equipped with a high-voltage insulator and a retractable conductive terminal; the current transformer primary terminal wiring device is equipped with a retractable conductive copper plate with a conductive pad; and the current transformer secondary terminal wiring device is equipped with a pin-type connector. The automatic electrical wiring device is driven by a servo motor or cylinder, and achieves automatic electrical connection between the voltage transformer and the calibration device through the voltage transformer primary terminal wiring device and the voltage transformer secondary terminal wiring device, and achieves automatic electrical connection between the current transformer and the calibration device through the current transformer primary terminal wiring device and the current transformer secondary terminal wiring device.

[0010] Optionally, the environmental monitoring device includes a temperature and humidity sensor, several cameras, and an audible and visual alarm. The temperature and humidity sensor is used to monitor the temperature or humidity of the calibration area. The several cameras are used to capture images of the storage area, calibration area, transfer area entrance, and transfer area exit, respectively. The audible and visual alarm is used to send an audible and visual alarm to the remote control terminal when the triggering conditions are met. The triggering conditions include the temperature of the calibration area exceeding a preset temperature range or the humidity of the calibration area exceeding a preset humidity range.

[0011] Optionally, the monitoring area also integrates auxiliary devices, including an industrial camera, a barcode reader, and a laser marking machine. The industrial camera is used to photograph the nameplate of the medium-voltage transformer, extract the transformer parameters based on the nameplate, and compare them with the tooling pallet information for pre-verification confirmation. The barcode reader is used to identify the tooling pallet information and compare it with the medium-voltage transformer parameters for pre-verification confirmation. The medium-voltage transformer parameters include serial number, model, and transformation ratio parameters. The laser marking machine is used to mark qualified medium-voltage transformers with a pass mark and verification time, and to mark unqualified medium-voltage transformers with a fail mark and fault type.

[0012] Optionally, the remote control terminal and the local device terminal can communicate in real time and transmit bidirectional encrypted data via an interconnection network for the video and audio information of the medium-voltage transformer and the control signals of the remote control terminal; the encryption transmission algorithm is the AES-128 encryption algorithm.

[0013] Optionally, the remote control terminal includes a switch, a PLC controller, and an industrial computer. The switch is used for real-time interconnection and bidirectional encrypted data transmission of video and audio information and control signals of the medium-voltage transformer. The PLC controller is used to send calibration tasks to the local equipment terminal. The industrial computer is used to obtain the nameplate information, calibration data, calibration results, calibration time, and environmental parameters of the medium-voltage transformer, and generate a calibration report. The local equipment terminal is equipped with an automatic door lock, and the status of the automatic door lock is displayed in real time on the display device of the remote control terminal.

[0014] This invention also provides a remote off-site verification method for medium-voltage instrument transformers, applied to the aforementioned remote off-site verification system for medium-voltage instrument transformers. The method includes: a remote control terminal sending a verification task to a local device; the local device transferring the medium-voltage instrument transformer to be verified to a verification device; an automatic electrical wiring device automatically connecting the medium-voltage instrument transformer and the verification device; and the verification device performing remote off-site measurements of insulation resistance, power frequency voltage, and error of the medium-voltage instrument transformer to be verified based on the received verification task, and sending the verification results to the remote control terminal.

[0015] The beneficial effects of this invention are as follows: 1. By using a remote control terminal and a local equipment terminal to form a remote deployment architecture, the geographical limitations of the verification operation are broken. Verification personnel can issue verification tasks and receive verification results without going to the site, achieving a verification effect with fewer or even no personnel on duty. This enables remote verification of medium-voltage transformers, reduces the cost of sending them for verification, and improves the efficiency of verification.

[0016] Meanwhile, the local equipment integrates functional modules of the storage area, transfer area, calibration area, and monitoring area. Through the coordinated operation of intelligent storage racks, conveyor lines, and automatic electrical wiring devices, it achieves fully automated operation of medium-voltage transformers from storage and transfer to calibration, replacing the traditional manual handling and wiring operation mode, and significantly shortening the calibration cycle of a single medium-voltage transformer. Furthermore, the environmental monitoring devices and auxiliary devices in the monitoring area can collect data on the calibration environment in real time and record the entire calibration process, ensuring the authenticity, accuracy, and traceability of the calibration results.

[0017] 2. The intelligent storage racks and stacking AGVs in the storage area, combined with tooling pallets equipped with positioning slots and cushioning rubber pads, enable precise classification and retrieval of instrument transformers in their pending, qualified, and unqualified states, automating inbound and outbound operations. This replaces manual handling and sorting, preventing damage to medium-voltage instrument transformers caused by manual operation. The stainless steel roller conveyor components in the transfer area are compatible with tooling pallets, enabling smooth and automatic transfer of instrument transformers across various functional areas, improving circulation efficiency. The automatic electrical wiring device in the calibration area automatically switches wiring modes based on instrument transformer parameters, using a dedicated terminal structure (high-voltage insulators, retractable conductive copper plates, pin-type terminals) to replace manual wiring operations, eliminating wiring errors caused by human fatigue and ensuring calibration accuracy. Auxiliary devices, including industrial cameras and barcode readers, enable automatic parameter acquisition and comparison, while laser marking machines automatically mark calibration results, further reducing manual intervention, minimizing reliance on manual labor and human error, and improving calibration accuracy. Attached Figure Description

[0018] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. The drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0019] Figure 1 This is a block diagram of a remote off-site calibration system for a medium-voltage instrument transformer according to the present invention; Figure 2 This is a schematic diagram of audio and video acquisition and transmission using a medium-voltage current transformer according to the present invention; Figure 3 This is a schematic diagram of the layout of a local equipment terminal laboratory for a medium-voltage instrument transformer according to the present invention; In the diagram, 1 is the remote calibration station; 2 is the connecting device; 3 is the shelf; 4 is the AGV stacker crane; and 5 is the remote door lock. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only one preferred embodiment of this invention and are only used to explain this invention. They do not limit the scope of protection of this invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0021] As one implementation, the present invention provides a remote off-site verification system for medium-voltage instrument transformers, comprising a remote control terminal and a local equipment terminal deployed in a different location; the remote control terminal is used to issue verification tasks to the local equipment terminal and receive verification results from the local equipment terminal; the local equipment terminal is used to perform remote off-site verification of the medium-voltage instrument transformers based on the received verification tasks; the local equipment terminal includes a storage area, a transfer area, a verification area, and a monitoring area; the storage area integrates intelligent storage racks for storing medium-voltage instrument transformers; the transfer area integrates a conveyor line for transferring and transporting medium-voltage instrument transformers between the storage area and the verification area; the verification area integrates an automatic electrical wiring device and a verification device, which automatically connects the medium-voltage instrument transformers and the verification device, thereby verifying the medium-voltage instrument transformers and sending the verification results to the remote control terminal; the monitoring area integrates an environmental monitoring device for monitoring the verification process of the medium-voltage instrument transformers.

[0022] The remote off-site verification system for medium-voltage instrument transformers in this embodiment deploys the remote control terminal in a legally authorized or specially authorized metrology laboratory, equipped with a switch, an industrial control computer (with dedicated management software), a high-definition display terminal, voice interaction equipment, and a PLC controller. The local equipment terminal is deployed in a standardized laboratory in a county-level or township-level user-concentrated area. The laboratory is divided into storage, transfer, verification, and monitoring areas. Each area integrates intelligent storage racks, conveyor lines, automatic electrical wiring devices, verification devices, and other components according to their functions, and establishes a communication connection with the remote control terminal via a network. Adopting a modular design approach and combining electronic measurement technology with digital information technology, the system achieves fully automated, unmanned operation of medium-voltage instrument transformers from storage, identification, transfer, wiring, verification to data archiving, meeting the requirements for remote, intelligent, and information-based verification.

[0023] Furthermore, such as Figure 1 As shown, the overall architecture can be divided into three layers: remote control PC, switch, and local device PC. The remote PC serves as the core of the remote control system, establishing connections with all local devices through the switch to achieve remote management, data reception, and status monitoring of the local verification process. The local device PC can include four main categories: storage system PC, PLC controller, verification warehouse control PC, environmental monitoring devices, and auxiliary devices. These are the execution units for completing the local verification tasks. The storage system PC can include AGV stacker trucks; the PLC controller can include remote control door locks, alarm lights, roller conveyors, voltage wiring devices, and current wiring devices; the verification warehouse control PC can include insulation testing devices, withstand voltage testing devices, voltage error testing devices, excitation characteristic testing devices, current error testing devices, and inter-turn insulation testing devices; and the environmental monitoring devices and auxiliary devices can include industrial cameras, laser marking devices, barcode recognition devices, and temperature and humidity sensors.

[0024] The conveyor line automatically transfers medium-voltage transformers to predetermined calibration positions. It includes a stainless steel roller conveyor assembly with an adjustable conveying speed (3-18 m / min). The roller conveyor assembly is convenient and easy to control. Eight position sensors are installed along the conveyor line to detect the transformer positions and trigger linkage signals. The storage area also integrates stacking AGVs and tooling pallets for supporting medium-voltage transformers. The stacking AGVs perform intelligent warehouse racking operations for medium-voltage transformers based on calibration tasks issued by a remote control terminal. They are equipped with a laser navigation module (navigation accuracy ±3 mm) and bidirectional arms (capable of supporting weight ≥150 kg). The laser navigation module navigates and positions the tooling pallets, while the bidirectional arms lift and place the pallets. Stacking AGVs are uniformly scheduled by intelligent storage racks. Through the combination of AGVs and automated racks, and seamless connection with conveyor lines, they have automatic inbound and outbound functions and automatic warehouse allocation functions. They can realize the automated storage and management of voltage transformers, current transformers, as well as inspected transformers, uninspected transformers, qualified transformers and unqualified transformers.

[0025] The intelligent warehouse racking system includes racks awaiting inspection, racks that have passed inspection, and racks that have failed inspection. The storage area also integrates stacking AGVs. These AGVs, based on inspection tasks issued by a remote control terminal, perform outbound operations from racks awaiting inspection for medium-voltage transformers; based on the inspection results from the inspection device, they perform inbound operations from racks that have passed inspection for medium-voltage transformers; and based on the inspection results from the inspection device, they perform inbound operations from racks that have failed inspection for medium-voltage transformers. The intelligent warehouse racking system adopts a three-dimensional racking structure, with a total of 100 storage locations. Each storage location corresponds to a unique barcode identifier, and a unique barcode is affixed to each tooling pallet. The intelligent warehouse racking system is linked with the remote control terminal to update the storage location occupancy status and transformer information in real time.

[0026] The tooling pallet is made of anti-static material and its size is compatible with mainstream medium-voltage transformers. The upper part has a first positioning slot for fixing the medium-voltage transformer, accommodating it and preventing damage from collisions. This also ensures the physical positioning of the transformer, guaranteeing accurate and seamless connection with the electrical terminals of the subsequent automatic electrical wiring device. The bottom of the tooling pallet has a second positioning slot for engaging with the roller conveyor assembly of the conveyor line and the bidirectional insert arm of the stacking AGV. The edges of the tooling pallet are equipped with cushioning rubber pads to absorb impacts during transport.

[0027] The automatic electrical wiring device can automatically switch the electrical wiring, load parameters, and transformation ratio parameters of various verification devices according to remote control verification requirements. It collects and uploads verification data and conclusions in real time, possessing high-precision measurement capabilities and compatibility with multiple types of medium-voltage transformers. The automatic electrical wiring device is driven by servo motors or cylinders, with a wiring accuracy of ±0.5mm. It switches wiring modes based on medium-voltage transformer parameters to complete wiring and disconnection operations for insulation resistance testing, power frequency withstand voltage testing, inter-turn insulation, excitation characteristics, and error testing. Driven by servo motors or cylinders, the automatic electrical wiring device achieves automatic electrical connection between voltage transformers and verification devices through primary and secondary terminal wiring devices, and automatically connects current transformers and verification devices through primary and secondary terminal wiring devices.

[0028] The primary terminal wiring device of a voltage transformer is equipped with high-voltage insulators and retractable conductive terminals. The primary and secondary terminal wiring devices of a voltage transformer must meet the wiring requirements for verification items such as insulation resistance, power frequency voltage, error, and excitation characteristics. The primary terminal wiring device of a current transformer is equipped with a retractable conductive copper plate with a conductive pad, and the secondary terminal wiring device of a current transformer is equipped with pin-type terminals (compatible with 2-6mm). 2 (Wires), the wiring device for the primary and secondary terminals of the current transformer must meet the wiring requirements for the current transformer error, inter-turn insulation and other verification items.

[0029] The calibration tasks include insulation resistance, power frequency voltage, and error measurement; the automatic electrical wiring devices include primary terminal wiring devices for voltage transformers, secondary terminal wiring devices for voltage transformers, primary terminal wiring devices for current transformers, and secondary terminal wiring devices for current transformers; the calibration equipment includes an insulation resistance tester, a withstand voltage tester, a voltage transformer error tester, and a current transformer error tester. The withstand voltage tester has an output voltage range of 0-50kV and an accuracy of ±0.5%; the insulation resistance tester has a measurement range of 1MΩ-10TΩ and an accuracy of ±1%; the current transformer error tester is equipped with a 0.02S class standard current transformer and a current booster (output current 0-2000A), and the voltage transformer error tester is equipped with a 0.02 class standard voltage transformer and a load cell (load range 5-80VA), both of which can automatically switch load parameters and transformation ratio parameters via remote control.

[0030] The environmental monitoring device includes temperature and humidity sensors, several cameras, and an audible and visual alarm. The temperature and humidity sensors monitor the temperature or humidity in the calibration area. The cameras capture images of the storage area, calibration area, transfer area entrance, and transfer area exit. Specifically, it is equipped with two temperature and humidity sensors (measurement range: temperature 0-40℃, accuracy ±0.2℃; humidity 20%-70%RH, accuracy ±2%RH) and four high-definition cameras (4K resolution, 25fps). The sensor data acquisition cycle is 1 second. The cameras are pointed at the storage area, calibration area, transfer area entrance, and transfer area exit to collect environmental data and images in real time. The audible and visual alarm sends an alarm to the remote control terminal when the temperature or humidity in the calibration area exceeds a preset range.

[0031] Reference Figure 2 The local equipment can be configured with four cameras: camera 1 facing the storage area, camera 2 facing the inspection area, camera 3 facing the entrance of the transfer area, and camera 4 facing the exit of the transfer area. All of them are connected to the remote control terminal through a switch. The remote control terminal can be configured with a video recorder, a display device, and a microphone. The video recorder is responsible for recording and storing audio and video, the display device is responsible for displaying video content in real time, and the microphone is responsible for collecting audio content from the remote control terminal in real time.

[0032] The auxiliary equipment includes an industrial camera, a barcode reader, and a laser marking machine. The industrial camera is used to photograph the nameplate of the medium-voltage transformer and extracts the transformer parameters using OCR software based on the nameplate. These parameters are then compared with the information on the tooling tray for pre-verification confirmation. The medium-voltage transformer parameters include serial number, model number, and transformation ratio. It is equipped with a 5-megapixel lens and OCR software, achieving a recognition success rate of ≥99%. The barcode reader is used to identify the information on the tooling tray and compare it with the medium-voltage transformer parameters for pre-verification confirmation. It uses a CCD scanning module with a scanning distance of 5-20cm and a response time ≤10ms. The laser marking machine (i.e., the test result label) is used to mark qualified medium-voltage transformers with a pass mark and verification time, and to mark unqualified medium-voltage transformers with a fail mark and fault type. The laser marking method includes information such as verification date, conclusion, and verification personnel.

[0033] Furthermore, the OCR software preprocesses the nameplate images captured by the industrial camera, including noise reduction, grayscale conversion, or character segmentation. Then, a trained OCR model is used to recognize the characters. The model is trained to optimize the font (SimSun or Heiti) and character arrangement (multi-row, multi-column) of the instrument transformer nameplate to improve the recognition accuracy of key parameters such as serial number, model number, and transformer ratio. The recognized parameters are then bound to the original nameplate image, packaged, and uploaded to the remote control terminal, while simultaneously being backed up in a local database on the local device.

[0034] The remote control terminal features two-way voice transmission, remote calibration operation, laboratory video display, door lock control, and temperature and humidity control. It includes a switch, PLC controller, and industrial computer. The switch is used for real-time interconnection and two-way encrypted data transmission of video and audio information and control signals from the medium-voltage transformers. The PLC controller sends calibration tasks to the local equipment. The PLC controller uses a Mitsubishi L-series and communicates with various actuators such as the conveyor line, automatic electrical wiring device, and calibration device via the Profinet bus, receiving field feedback signals and issuing control commands.

[0035] The industrial control computer (ICC) is used to acquire nameplate information, calibration data, calibration results, calibration time, and environmental parameters of medium-voltage instrument transformers, and to generate calibration reports. The ICC is equipped with dedicated management software and connects to the controller via an industrial bus. It supports functions such as calibration task creation, calibration process monitoring, calibration data querying, and calibration report generation. It is used to generate control commands, monitor the work process in real time, store calibration data, and enable remote task distribution, process control, and emergency handling.

[0036] The remote control terminal also includes a display device and a voice interaction device. The remote control terminal acquires the nameplate information, verification data, verification results, verification time, and environmental parameters of the medium-voltage transformer, and generates a verification report. The local equipment is equipped with an automatic door lock, and the status of the automatic door lock is displayed in real time on the display device of the remote control terminal. Once the verification task begins, the remote control terminal automatically locks the laboratory door to prevent unauthorized personnel from interfering with the verification process. Video, audio, and control signals are transmitted via an encrypted network to ensure secure and stable data transmission, prevent data leakage or tampering, and guarantee the authenticity of the measurement data.

[0037] Furthermore, refer to Figure 3Shelf 3: Located in the lower area of ​​the laboratory, it serves as a storage container for materials, used to classify and store current transformers that are to be verified or have already been verified. AGV Stacker Crane 4: Deployed next to Shelf 3, it is an automated transfer device responsible for retrieving or placing current transformers from Shelf 3, enabling automated inbound and outbound operations. Connecting Device 2: Connecting Shelf 3 and Remote Verification Station 1, it acts as a transfer unit for material transfer, working in conjunction with AGV Stacker Crane 4 to complete the precise handover of materials. Remote Verification Station 1: Located above the laboratory, it is an enclosed space for core testing operations, used for conducting specific tests on materials (such as current transformer verification tests). Remote Door Lock 5: Installed on the laboratory door, it enables remote control of the laboratory's opening and closing, ensuring the laboratory's sealing and security.

[0038] The remote control terminal and the local device terminal are interconnected in real time and transmit video information, audio information and control signals in two-way encrypted transmission via an interconnection network; the encrypted transmission is encrypted using the AES-128 encryption algorithm, with a transmission delay of ≤30ms, ensuring the real-time performance and security of remote control.

[0039] This invention, through the coordinated operation of the aforementioned devices, deploys the experimental chamber, i.e. the verification device, where the local equipment is located, in counties, cities, and townships close to user areas. Operators can remotely complete the entire verification and control process, breaking geographical limitations and realizing on-site automated verification of medium-voltage transformers. This significantly reduces the cost and time for users to send transformers for verification, eliminating the need for users to transport transformers to the municipal metering center. It effectively solves the problem of difficult verification for users in remote areas and improves the quality and coverage of power supply company verification services.

[0040] This invention achieves fully unmanned and automated verification: through the coordinated operation of intelligent storage racks, conveyor lines, and automatic electrical wiring devices, it replaces manual labor in completing the entire process of medium-voltage transformer entry and exit, transfer, wiring, and verification. Combined with information recognition and parameter matching of auxiliary devices, it significantly reduces human error and ensures the consistency and accuracy of verification results.

[0041] This invention supports remote and precise control and multi-scenario applications: relying on the Internet to achieve remote control, operators can complete the issuance of verification tasks, monitoring of verification processes, viewing of verification data and emergency handling remotely. At the same time, it meets the needs of power supply companies for supervision and acceptance of medium-voltage transformers, as well as the needs of technical supervision departments for quality spot checks and supervision of transformer manufacturers' products within their jurisdiction, thereby improving the flexibility and efficiency of supervision.

[0042] This invention is highly adaptable and easily expandable: it adopts a modular design approach, combining multiple types of voltage connection devices, current connection devices, and verification devices, which can be adapted to medium-voltage transformers of different models and specifications, support batch verification operations, and the modules can be flexibly added or removed according to needs to meet diverse verification and future functional expansion requirements.

[0043] This invention offers reliable data security and environmental control: encrypted transmission technology ensures the security of video, audio, and control signal transmission; automatic door locking and real-time environmental monitoring during the experiment effectively prevent human interference and environmental fluctuations from affecting the verification process, ensuring the authenticity and traceability of measurement data.

[0044] As one implementation method, the verification process of the remote off-site verification system for applied voltage transformers provided in this embodiment is as follows: S1. Task Initiation and Medium-Voltage Transformer Storage: The user delivers the medium-voltage transformers to be calibrated (e.g., 5 10kV current transformers) to the local equipment terminal laboratory deployed in the township. Staff place the transformers on a tooling pallet, bind the pallet and transformer information via a barcode scanner, and the stacking AGV receives transfer instructions from the intelligent storage rack, transferring the pallet to the inspection area of ​​the automated storage and retrieval system, completing the storage process. Remote operators create a calibration task in the control software, selecting the transformer type and calibration items (insulation resistance, power frequency voltage, and error measurement), and issue it to the local equipment terminal.

[0045] S2. Information Identification and Transfer: After receiving the task, the local equipment grabs the corresponding tooling pallet from the inspection area and transfers it to the conveyor line entrance via the connecting device. The conveyor line starts and transports the tooling pallet to the auxiliary device area. The industrial camera takes a picture of the current transformer nameplate and extracts the information. The barcode reader scans the barcode of the tooling pallet. The remote control terminal compares and confirms the information of the two (e.g., model LZZBJ9-10, ratio 600 / 5A) and sends the parameters to the automatic electrical wiring device and the verification device.

[0046] S3. Automatic Wiring and Verification: The conveyor line transports the current transformers to the verification station. The position sensor triggers a signal, and the automatic electrical wiring device switches to the current transformer primary winding insulation resistance test wiring mode according to the received parameters. The servo motor drives the conductive contacts and pin terminals to complete the wiring. The remote control terminal issues a start command, and the verification device sequentially performs insulation resistance testing, power frequency voltage testing, and error measurement. The test data for each step is collected in real time and uploaded to the remote industrial control computer. If the insulation resistance value of a certain current transformer is lower than the standard threshold (e.g., <1000MΩ), the remote control terminal automatically determines it as unqualified, marks the information, and suspends the subsequent verification of the medium-voltage current transformer.

[0047] S4. Result Identification and Warehousing: After the verification is completed, the laser marking machine of the auxiliary device prints a qualified label on the outer shell of the current transformer; the conveyor line transfers the qualified current transformer to the exit area, and the stacking AGV grabs the pallet and transfers it to the inspected qualified area of ​​the three-dimensional rack; the unqualified current transformer is transferred to the inspected unqualified area, and at the same time the system sends an alarm prompt to the remote control terminal.

[0048] S5. Remote Monitoring and Safety Management: After the verification begins, remote operators control the laboratory door locks to automatically lock via the management software. The door lock status is displayed in real time on the high-definition display device at the remote control terminal. The environmental monitoring device continuously uploads temperature and humidity data and on-site images. If the laboratory temperature is controlled between 18℃ and 22℃ and the humidity exceeds 80%, an audible and visual alarm is automatically triggered to remind the remote operator to start the laboratory dehumidification. The entire process involves two-way transmission of voice signals. If any abnormality occurs on-site, the remote operator can immediately issue an emergency stop command.

[0049] S6. Data Archiving and Report Generation: After the verification task is completed, the remote control software automatically summarizes the nameplate information, test data, verification conclusions, environmental parameters and operation time of each instrument transformer, and generates a standardized verification report. The report can be exported as a PDF for storage or printed directly, realizing full traceability of the verification process. If the technical supervision department needs to conduct random inspections of a manufacturer's products, it can remotely retrieve the corresponding batch verification data without on-site verification.

[0050] Through the above specific implementation methods, the remote off-site verification system for medium-voltage instrument transformers of the present invention can realize fully automated and remote verification close to users, greatly reduce the cost of sending instruments for verification, improve verification efficiency and regulatory flexibility, and meet the high-standard requirements of power supply company supervision and acceptance and technical supervision department quality spot checks.

[0051] This invention also provides a remote off-site verification method for medium-voltage instrument transformers, applied to a remote off-site verification system for medium-voltage instrument transformers, comprising: a remote control terminal sending a verification task to a local equipment terminal; the local equipment terminal transferring the medium-voltage instrument transformer to be verified to a verification device; the verification device performing remote off-site insulation resistance, power frequency voltage, and error measurements on the medium-voltage instrument transformer to be verified based on the received verification task, and sending the verification results to the remote control terminal.

[0052] Compared with the prior art, the present invention has the following beneficial effects based on the above embodiments: 1. By using a remote control terminal and a local equipment terminal to form a remote deployment architecture, the geographical limitations of the verification operation are broken. Verification personnel can issue verification tasks and receive verification results without going to the site, achieving a verification effect with fewer or even no personnel on duty. This enables remote verification of medium-voltage transformers, reduces the cost of sending them for verification, and improves the efficiency of verification.

[0053] Meanwhile, the local equipment integrates functional modules of the storage area, transfer area, calibration area, and monitoring area. Through the coordinated operation of intelligent storage racks, conveyor lines, and automatic electrical wiring devices, it achieves fully automated operation of medium-voltage transformers from storage and transfer to calibration, replacing the traditional manual handling and wiring operation mode, and significantly shortening the calibration cycle of a single medium-voltage transformer. Furthermore, the environmental monitoring devices and auxiliary devices in the monitoring area can collect data on the calibration environment in real time and record the entire calibration process, ensuring the authenticity, accuracy, and traceability of the calibration results.

[0054] 2. The intelligent storage racks and stacking AGVs in the storage area, combined with tooling pallets equipped with positioning slots and cushioning rubber pads, enable precise classification and retrieval of instrument transformers in their pending, qualified, and unqualified states, automating inbound and outbound operations. This replaces manual handling and sorting, preventing damage to medium-voltage instrument transformers caused by manual operation. The stainless steel roller conveyor components in the transfer area are compatible with tooling pallets, enabling smooth and automatic transfer of instrument transformers across various functional areas, improving circulation efficiency. The automatic electrical wiring device in the calibration area automatically switches wiring modes based on instrument transformer parameters, using a dedicated terminal structure (high-voltage insulators, retractable conductive copper plates, pin-type terminals) to replace manual wiring operations, eliminating wiring errors caused by human fatigue and ensuring calibration accuracy. Auxiliary devices, including industrial cameras and barcode readers, enable automatic parameter acquisition and comparison, while laser marking machines automatically mark calibration results, further reducing manual intervention, minimizing reliance on manual labor and human error, and improving calibration accuracy.

[0055] The specific embodiments described above are preferred embodiments of a remote off-site calibration system and method for medium-voltage instrument transformers according to this application, and are not intended to limit the specific scope of this application. The scope of this application includes but is not limited to the specific embodiments described above. All equivalent changes made in accordance with the shape and structure of this application are within the protection scope of this application.

Claims

1. A remote off-site calibration system for medium-voltage instrument transformers, characterized in that, It includes a remote control terminal and a local equipment terminal deployed in different locations. The remote control terminal is used to issue calibration tasks to the local equipment terminal and receive calibration results from the local equipment terminal. The local equipment terminal is used to remotely calibrate medium-voltage transformers based on the received calibration tasks. The local equipment terminal includes a storage area, a transfer area, a calibration area, and a monitoring area. The storage area integrates intelligent storage racks to store medium-voltage transformers. The transfer area integrates a conveyor line to transfer medium-voltage transformers between the storage area and the calibration area. The calibration area integrates an automatic electrical wiring device and a calibration device. The automatic electrical wiring device enables automatic electrical connection between the medium-voltage transformer and the calibration device, and then the calibration device calibrates the medium-voltage transformer and sends the calibration results to the remote control terminal. The monitoring area integrates an environmental monitoring device to monitor the calibration process of the medium-voltage transformer.

2. The remote off-site calibration system for a medium-voltage instrument transformer according to claim 1, characterized in that, The intelligent warehouse racking system includes racks awaiting inspection, racks that have passed inspection, and racks that have failed inspection. The storage area also integrates stacking AGVs. Based on the inspection tasks issued by the remote control terminal, the stacking AGVs perform outbound operations for racks awaiting inspection of medium-voltage transformers, and perform inbound operations for racks that have passed inspection of medium-voltage transformers based on the inspection results of the inspection device. Based on the inspection results of the inspection device, the stacking AGVs perform inbound operations for racks that have failed inspection of medium-voltage transformers based on the inspection results of the inspection device.

3. The remote off-site calibration system for a medium-voltage instrument transformer according to claim 1, characterized in that, The storage area also integrates tooling pallets for supporting medium-voltage transformers. The stacking AGV is equipped with a laser navigation module and a bidirectional extension arm. The laser navigation module is used to navigate and position the tooling pallet, and the bidirectional extension arm is used to lift and place the tooling pallet. The upper part of the tooling pallet is provided with a first positioning groove for fixing the medium-voltage transformer, and the bottom of the tooling pallet is provided with a second positioning groove that is adapted to engage with the roller conveyor assembly of the conveyor line and the bidirectional extension arm of the stacking AGV. The edges of the tooling pallet are provided with cushioning rubber pads for buffering the impact of the transfer.

4. The remote off-site calibration system for a medium-voltage instrument transformer according to claim 1, characterized in that, The verification tasks include insulation resistance, power frequency voltage, and error measurement; the verification equipment includes an insulation resistance tester for measuring insulation resistance, a withstand voltage test device for measuring power frequency voltage, a voltage transformer error test device, and a current transformer error test device for measuring errors.

5. A remote off-site calibration system for a medium-voltage instrument transformer according to claim 4, characterized in that, The automatic electrical wiring device includes a voltage transformer primary terminal wiring device, a voltage transformer secondary terminal wiring device, a current transformer primary terminal wiring device, and a current transformer secondary terminal wiring device. The voltage transformer primary terminal wiring device is equipped with a high-voltage insulator and a retractable conductive terminal. The current transformer primary terminal wiring device is equipped with a retractable conductive copper plate with a conductive pad. The current transformer secondary terminal wiring device is equipped with a pin-type connector. The automatic electrical wiring device is driven by a servo motor or cylinder and achieves automatic electrical connection between the voltage transformer and the calibration device through the voltage transformer primary terminal wiring device and the voltage transformer secondary terminal wiring device, and achieves automatic electrical connection between the current transformer and the calibration device through the current transformer primary terminal wiring device and the current transformer secondary terminal wiring device.

6. A remote off-site calibration system for a medium-voltage instrument transformer according to claim 1, characterized in that, The environmental monitoring device includes a temperature and humidity sensor, several cameras, and an audible and visual alarm. The temperature and humidity sensor is used to monitor the temperature or humidity of the calibration area. The several cameras are used to capture images of the storage area, calibration area, transfer area entrance, and transfer area exit, respectively. The audible and visual alarm is used to send an audible and visual alarm prompt to the remote control terminal when the trigger conditions are met. The trigger conditions include the temperature of the calibration area exceeding the preset temperature range or the humidity of the calibration area exceeding the preset humidity range.

7. A remote off-site calibration system for a medium-voltage instrument transformer according to claim 2, characterized in that, The monitoring area also integrates auxiliary devices, including industrial cameras, barcode readers, and laser marking machines. The industrial cameras are used to photograph the nameplates of the medium-voltage transformers, extract their parameters based on the nameplates, and compare them with the information on the tooling tray for pre-verification confirmation. The barcode readers are used to identify the tooling tray information and compare it with the medium-voltage transformer parameters for pre-verification confirmation. The medium-voltage transformer parameters include serial number, model number, and transformation ratio. The laser marking machine is used to mark qualified medium-voltage transformers with a pass mark and verification time, and to mark unqualified medium-voltage transformers with a fail mark and fault type.

8. A remote off-site calibration system for a medium-voltage instrument transformer according to claim 1, characterized in that, The remote control terminal and the local equipment terminal are interconnected in real time and transmitted bidirectionally with encrypted data via an interconnection network for video and audio information of medium-voltage transformers and control signals of the remote control terminal; the encryption transmission algorithm is AES-128 encryption algorithm.

9. A remote off-site calibration system for a medium-voltage instrument transformer according to claim 8, characterized in that, The remote control terminal includes a switch, a PLC controller, and an industrial computer. The switch is used for real-time interconnection and bidirectional encrypted data transmission of video and audio information and control signals of the medium-voltage transformer. The PLC controller is used to send calibration tasks to the local equipment terminal. The industrial computer is used to obtain the nameplate information, calibration data, calibration results, calibration time, and environmental parameters of the medium-voltage transformer, and generate a calibration report. The local equipment terminal is equipped with an automatic door lock, and the status of the automatic door lock is displayed in real time on the display device of the remote control terminal.

10. A remote off-site calibration method for a medium-voltage instrument transformer, applied to a remote off-site calibration system for a medium-voltage instrument transformer as described in any one of claims 1 to 9, characterized in that, include: The remote control terminal sends the verification task to the local equipment terminal; The local equipment transfers the medium-voltage transformer to be tested to the testing device. The automatic electrical wiring device automatically connects the medium-voltage transformer and the testing device. Based on the received testing task, the testing device remotely measures the insulation resistance, power frequency voltage and error of the medium-voltage transformer to be tested, and sends the testing results to the remote control terminal.

Images