Automatic voltage regulating method and automatic voltage regulating device for portable on-load transformer

Abstract

The invention discloses an automatic voltage regulation method and device for a portable on-load transformer, and the method comprises the steps: collecting images corresponding to a push rod when a gear-shifting knob of the on-load transformer is located at different gears in the process that the push rod of a gear-shifting mechanism pushes the gear-shifting knob for gear shifting, so as to build a feature image library of the images of the push rod under each gear; when gear adjustment is carried out each time, whether gear adjustment is completed or not is comprehensively judged according to the resistance change condition of swing of the push rod when the gear adjustment knob is pushed and the push rod image collected in real time, and the current push rod image collected when gear adjustment is completed is compared with the image of the corresponding gear in the feature image library to determine whether gear adjustment is correct or not. Whether the gear shifting process is completed or not can be comprehensively judged, and the accuracy of each gear shifting operation is ensured; the gear corresponding to the current push rod is accurately recognized, so that whether the gear is correctly shifted to the target gear or not is accurately judged, the gear recognition precision is high, and the reliability is high.

Description

Technical Field

[0001] The invention relates to the technical field of on-load transformers, and in particular to a portable on-load transformer automatic voltage regulation method and an automatic voltage regulation device. Background Art

[0002] The transformer on-load voltage regulation mechanism can change the number of turns of the coil by adjusting the tap of the coil on one side of the transformer to achieve the purpose of changing the output voltage, and realize the load regulation of the low-voltage side voltage without shutting down the transformer. When carrying out routine maintenance tests on transformers, such as winding DC resistance measurement and winding insulation resistance measurement, on-site test personnel are often required to manually adjust the gear (such as: from 1 gear to 17 gear, and then from 17 gear to 1 gear), and polish and remove rust according to the test results, and repeat the measurement data for multiple rounds until the test data is qualified.

[0003] During the gear adjustment process, in addition to the test personnel and the supervisor, a special person needs to be assigned to perform the gear adjustment operation, who is responsible for manually operating the gear adjustment knob on the on-load voltage regulating mechanism of the transformer, and observing the changes according to the transformer gear display panel to judge the current gear. This gear adjustment method is inefficient and will increase labor costs. In addition, there are currently devices that can automatically adjust the voltage of the gear adjustment knob, such as a wireless controller and on-load voltage regulating transformer group mentioned in the Chinese invention patent publication number CN117833448A. Through reasonable control, it is possible to improve work efficiency while ensuring the accuracy of the test. However, the method of obtaining the actual gear position of the transformer in this invention patent is not reliable, and the staff still needs to observe and judge the gear position changes through human eyes, which not only consumes test time, but is also greatly affected by the installation location and operating environment, affecting the accuracy of the test data, and is not intelligent enough. Summary of the invention

[0004] The technical problem to be solved by the present invention is as follows: In view of the above-mentioned problems in the prior art, a portable on-load transformer automatic voltage regulation method and an automatic voltage regulation device with accurate gear detection and high efficiency are provided.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: A portable on-load transformer automatic voltage regulation method, comprising: S1, collecting images corresponding to the push rod when the gear adjustment knob of the on-load transformer is in each different gear position during the gear adjustment process when the push rod of the gear adjustment mechanism pushes the gear adjustment knob of the on-load transformer to establish a feature image library of the push rod images in each gear position; S2, whenever the gear is adjusted, a comprehensive judgment is made as to whether the gear adjustment is completed based on the change in the resistance of the push rod swinging when the gear adjustment knob is pushed and the push rod image collected in real time, and the current push rod image collected when the gear adjustment is completed is compared with the image of the corresponding gear in the feature image library to determine whether the gear adjustment is correct.

[0006] Furthermore, in step S1, the step of establishing a feature image library of the position of the push rod in each gear position includes: Grayscale each collected image; The grayscale processed image is subjected to edge detection processing, and the image feature value of the image and the swing center angle of the putter are calculated based on the image after the edge detection processing.

[0007] Furthermore, the calculation expression of the image feature value is: , In the above formula, is the image feature value of the mth pixel in the image, are the horizontal and vertical coordinates of the mth pixel in the image, respectively. is the gray value of the mth pixel in the image; The calculation expression of the swing center angle of the push rod is: , In the above formula, is the swing center angle of the push rod, are the horizontal and vertical axis positions of the swing center of the push rod, are the horizontal and vertical axis positions of the axis skeleton of the putter in the i-th putter image, respectively. is the angle of the axis skeleton of the putter in the i-th putter image, and n is the total number of putter images.

[0008] Further, in step S2, the step of comprehensively judging whether the gear shifting is completed according to the change in the resistance of the push rod swinging when the gear shifting knob is pushed and the push rod image collected in real time includes: If the resistance to the swing of the push rod suddenly increases or decreases, it indicates that the gear shifting process has started or ended; if the resistance remains stable, it indicates that the gear shifting is continuing; if the resistance is zero, it indicates that the gear shifting has been completed or no gear shifting operation has been performed; If the position of the push rod in the collected push rod image continues to change, it indicates that the gear is being adjusted; if the position of the push rod does not change in the push rod image within the preset range, it indicates that the gear adjustment is completed.

[0009] Furthermore, in step S2, the current push rod image acquired when the gear adjustment is completed is compared with the image of the corresponding gear in the feature image library to determine whether the gear adjustment is correct, including: Calculate the image feature value of the current push rod image after grayscale processing and edge detection processing when the gear adjustment is completed, and perform similarity comparison with the image feature value of the feature image corresponding to each gear in the feature image library through Euclidean distance to obtain the most similar feature image, and judge whether the gear corresponding to the most similar feature image is consistent with the target adjustment gear. If they are consistent, the gear adjustment is correct.

[0010] Furthermore, the calculation expression for similarity comparison using Euclidean distance is: , In the above formula, is the Euclidean distance between the image feature value of the n-th feature image and the image feature value of the current putter image, m is the m-th pixel in the image, N is the total number of pixels in the image, is the image feature value of the mth pixel of the current push rod image, is the image feature value of the mth pixel of the feature image.

[0011] Furthermore, step S2 further includes: Whenever the gear is adjusted, the swing angle of the push rod is detected by the angle detection device, and the gear rotation volume of the gear adjustment mechanism is detected by the sound detection device to comprehensively judge whether the gear adjustment is completed. If the swing angle of the push rod is detected to be lower than the threshold and the gear rotation sound is continuously detected when the drive motor rotates, it indicates that the gear adjustment is completed; otherwise, it indicates that the push rod is separated from the gear adjustment button or the gear adjustment mechanism operates abnormally; The swing angle of the current push rod collected by the angle detection device when the gear adjustment is completed is compared with the swing center angle of the push rod in the image of the corresponding gear in the feature image library. If the error between the two is less than the preset range, it indicates that the gear adjustment is correct.

[0012] Furthermore, the portable on-load transformer automatic voltage regulation method also includes: If the collected push rod image contains the gear display information of the loaded transformer, a feature image library of the gear display information under each gear is established, and when the gear is adjusted, a comprehensive judgment is made as to whether the gear adjustment is completed based on the resistance change and the gear display information collected in real time, and the current gear display information collected when the gear adjustment is completed is compared with the gear display information in the feature image library to determine whether the gear adjustment is correct.

[0013] In addition, the present invention also provides a portable on-load transformer automatic voltage regulating device, including: a gear adjustment mechanism, an image acquisition device and a main control device; The gear-shifting mechanism is installed on the on-load tap changer of the on-load transformer and is used to perform a gear-shifting operation on the gear-shifting knob on the on-load tap changer control box; the gear-shifting mechanism includes a driving motor and a push rod, one end of the push rod is drivingly connected to the output shaft of the motor, and the other end is fixedly connected to the gear-shifting knob, so that the push rod can drive the gear-shifting knob to realize the gear-shifting operation; The image acquisition device includes a number of wireless cameras for acquiring images of the on-load tap changer control box and the push rod in the gear-shifting mechanism; The main control device shown includes a main controller, an image processing module and a display module that are communicatively connected to the gear shifting mechanism and the image acquisition device; the main controller is used to drive the push rod of the gear shifting mechanism according to the gear position to be shifted to drive the gear shifting knob to realize the gear shifting operation, judge whether the gear shifting is correct according to the real-time push rod image captured by the image acquisition device, prohibit the next operation and generate an alarm message when the gear position is not identified or the gear shifting mechanism is not reset; the image processing module is used to process and compare the collected push rod image of the gear shifting mechanism; the display module is used to present the gear shifting progress in real time.

[0014] Furthermore, the portable on-load transformer automatic voltage regulating device further comprises: angle detection equipment detection and sound detection equipment; The angle detection device comprises an encoding disc, the two ends of which are respectively connected to the driving motor and the push rod, and are used to detect the swing angle of the push rod; The sound detection device is installed at the gear of the gear shifting mechanism and is used to detect the rotation volume of the gear of the gear shifting mechanism; the sound detection device includes one or more of a sound level meter, a microphone, and an acoustic sensor.

[0015] Compared with the prior art, the advantages of the present invention are: The present invention can record the positional relationship of the push rod in different gears by collecting push rod images and establishing a feature image library, so as to facilitate the subsequent matching and confirmation of the gear corresponding to the position of the push rod according to the image, thereby improving the overall efficiency; through the change of the resistance of the push rod swinging and the push rod image collected in real time, it can be comprehensively judged whether the gear adjustment process is completed, thereby ensuring the accuracy of each gear adjustment operation; by comparing the push rod image collected in real time with the feature image library, it can accurately identify the gear corresponding to the current push rod, thereby accurately judging whether the gear is correctly adjusted to the target gear, and the gear recognition accuracy is high and the reliability is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a flow chart of a portable on-load transformer automatic voltage regulation method according to an embodiment of the present invention.

[0017] Figure 2 It is a schematic diagram of the overall structural framework of the automatic voltage regulating device according to an embodiment of the present invention.

[0018] Figure 3 It is a schematic diagram of a push rod of a gear-shifting mechanism in an automatic pressure-regulating device according to an embodiment of the present invention swinging under the drive of a motor to realize a gear-shifting operation on a gear-shifting knob.

[0019] Figure 4 It is a front view of the gear shifting mechanism according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0021] like Figure 1 As shown, the present invention provides a portable on-load transformer automatic voltage regulation method in one embodiment, comprising: S1, collecting images corresponding to the push rod when the gear adjustment knob of the on-load transformer is in each different gear position during the gear adjustment process when the push rod of the gear adjustment mechanism pushes the gear adjustment knob of the on-load transformer to establish a feature image library of the push rod images in each gear position; S2, whenever the gear is adjusted, a comprehensive judgment is made as to whether the gear adjustment is completed based on the change in the resistance of the push rod swinging when the gear adjustment knob is pushed and the push rod image collected in real time, and the current push rod image collected when the gear adjustment is completed is compared with the image of the corresponding gear in the feature image library to determine whether the gear adjustment is correct.

[0022] It can be understood that this embodiment can record the positional relationship of the push rod in different gears by collecting push rod images and establishing a feature image library, so as to facilitate the subsequent matching and confirmation of the gear corresponding to the position of the push rod according to the image, thereby improving the overall efficiency; through the change in the resistance of the push rod swing and the push rod image collected in real time, it can be comprehensively judged whether the gear shifting process is completed to ensure the accuracy of each gear shifting operation; by comparing the push rod image collected in real time with the feature image library, the gear corresponding to the current push rod can be accurately identified, thereby accurately judging whether the gear is correctly shifted to the target gear, and the gear recognition accuracy is high and the reliability is strong.

[0023] In order to better explain the automatic voltage regulation method of this embodiment, the automatic voltage regulation device used for voltage regulation of this embodiment is first briefly described. Figure 2 As shown, the automatic voltage regulating device mainly includes a gear adjustment mechanism, an image acquisition device and a main control device. The gear adjustment mechanism is installed on the on-load tap changer of the portable on-load transformer, and is used to perform gear shifting operations on the gear adjustment knob on the on-load tap changer control box. The image acquisition device is generally a wireless camera, and there are multiple of them. Each wireless camera is used in conjunction with one of the gear adjustment mechanisms to collect real-time images of the corresponding gear adjustment mechanism. The main control center mainly includes a main controller, which is used to control the gear adjustment operation of the gear adjustment mechanism according to the image information of the gear adjustment mechanism obtained by the wireless camera. Please refer to Figure 3The gear shifting mechanism mainly includes a driving motor and a push rod driven by the motor. One end of the push rod is connected to the output shaft of the motor, and the other end of the push rod is fixedly connected to the gear shifting knob, so that the push rod can drive the gear shifting knob to achieve the gear shifting operation. One part of the push rod is outside the gear shifting housing and is the visible part, and the other side is inside the housing and is the invisible part. When the image acquisition device actually captures the image, the push rod captures the swing of the visible part. For example, when the push rod is in positions a, b, and c, it operates the gear shifting knobs in different positions respectively. At this time, the swing angles of the push rod relative to the gear shifting mechanism housing are different.

[0024] In step S1 of this embodiment, a feature image library of the position of the push rod in each gear is established, including: Grayscale each collected image; The grayscale processed image is subjected to edge detection processing, and the image feature value of the image and the swing center angle of the putter are calculated based on the image after the edge detection processing.

[0025] In this embodiment, the calculation expression of the image feature value is: (1) In the above formula, is the image feature value of the mth pixel in the image, are the horizontal and vertical coordinates of the mth pixel in the image, respectively. is the gray value of the mth pixel in the image.

[0026] The calculation expression of the swing center angle of the push rod is: (2) In the above formula, is the swing center angle of the push rod, are the horizontal and vertical axis positions of the swing center of the push rod, are the horizontal and vertical axis positions of the axis skeleton of the putter in the i-th putter image, respectively. is the angle of the axis skeleton of the putter in the i-th putter image, and n is the total number of putter images.

[0027] In a specific application embodiment, collecting and establishing a feature image library of the position of the push rod in each gear position includes the following steps: Step 1, image acquisition: The push rod is driven by the motor of the gear adjustment mechanism to swing from the starting position to the end position, and the visible part of the push rod is photographed by the image acquisition device to realize the push rod image acquisition of each gear. The camera is preferably fixed on the gear adjustment machine to ensure that the RGB image of each gear push rod can be clearly and stably acquired during the gear adjustment process. For example, the gear adjustment knob of the on-load transformer can adjust the voltage of 17 gears in total, and the final push rod images collected are 17, each corresponding to a gear, and a feature image library is established using these push rod images.

[0028] Step 2, image preprocessing: preprocess the collected image (each pixel is determined by three components: R, G, and B), including grayscale, denoising, image enhancement and other operations. Grayscale processing can reduce the computational complexity of the image, while denoising and image enhancement can help improve the clarity and recognition rate of the image. The calculation expression of the grayscale value is as follows: (3) In the above formula, are the pixel values ​​corresponding to the red, green and blue channels of the mth pixel in the image, and the weight coefficients corresponding to red, green and blue are multiplied by them. The specific values ​​of the weight coefficients can be adjusted as needed. The values ​​in formula (3) are only the preferred values.

[0029] Step 3, image feature extraction: Use image recognition algorithms (such as convolutional neural networks, CNN) to extract gear features from the preprocessed image. Feature extraction includes edge detection, shape recognition, and key point detection. These features are used to determine the position of the putter in the image so that the current gear can be accurately identified under the influence of various factors (such as lighting conditions, camera angles, and clarity) during the recognition process. Specifically, the Roberts operator is used for edge detection, and the output grayscale image is filtered in the horizontal and vertical directions respectively, using an N*N (N is generally 2) dimensional matrix edge recognition filter. Subsequently, the image feature value of each putter image is calculated using formula (1).

[0030] Step 4, push rod position determination: using the push rod contour information extracted at the starting position as a reference, determine the push rod contour and axis skeleton in the push rod image corresponding to each gear position (because the appearance of the push rod has not changed, using the image within the push rod contour obtained at the starting position as a reference, the push rod posture in all subsequent images can be determined by image matching; in addition, the visible part of the push rod at the starting position and the ending position is the smallest, and one of them can be used as a reference). Formula (2) is used to calculate and determine the push rod swing center angle, the push rod swing center horizontal axis position and vertical axis position, the horizontal axis position and vertical axis position of the push rod axis skeleton in the push rod image of each gear position, the push rod axis skeleton angle in the push rod image, and other information, thereby providing more auxiliary information for subsequent comprehensive judgment of the gear adjustment progress and whether the adjustment is correct.

[0031] In step S2 of this embodiment, whether the gear shifting is completed is comprehensively judged according to the change of the resistance of the push rod swinging when the gear shifting knob is pushed and the push rod image collected in real time, including: If the resistance to the push rod swing suddenly increases or decreases, it indicates that the gear shifting process has started or ended; if the resistance remains stable, it indicates that the gear shifting is continuing; if the resistance is zero, it indicates that the gear shifting has been completed or no gear shifting operation has been performed; If the position of the push rod in the collected push rod image continues to change, it indicates that the gear is being adjusted; if the position of the push rod does not change in the push rod image within the preset range, it indicates that the gear adjustment is completed.

[0032] It can be understood that in order to ensure that the detection of the gear shifting progress is more reliable, this embodiment makes a comprehensive judgment through the resistance change of the push rod swinging and the push rod image collected in real time. Specifically, on the one hand, it is judged according to the driving force feedback information of the gear shifting mechanism to the push rod. The gear shifting mechanism drives the push rod to swing at a uniform angular velocity, and senses the resistance change of the push rod swinging during the entire stroke process through force feedback. The resistance situation in the entire gear shifting process is changing, especially the resistance situation of the push rod when entering and exiting the gear. If the resistance suddenly increases or decreases, it indicates that the gear shifting process has started or ended. If the resistance continues to be stable and does not change much, it indicates that the gear shifting is continuing. If the resistance change is zero, it indicates that the gear shifting has been completed or the gear shifting operation has not been performed. By monitoring the resistance in the entire stroke, a reference is provided for the judgment of the gear shifting progress. In addition, during the gear shifting process, the push rod image is collected in real time by the image acquisition device at regular intervals. According to whether the push rod position in the push rod image at different times changes significantly, it is judged whether it is currently in the gear shifting process or the gear shifting is completed. It is combined with the above-mentioned push rod resistance change information to more accurately judge the gear shifting progress.

[0033] In step S2 of this embodiment, the current push rod image collected when the gear adjustment is completed is compared with the image of the corresponding gear in the feature image library to determine whether the gear adjustment is correct, including: Calculate the image feature value of the current push rod image after grayscale processing and edge detection processing when the gear adjustment is completed, and compare the image feature value of the feature image corresponding to each gear in the feature image library through Euclidean distance to obtain the most similar feature image, and judge whether the gear corresponding to the most similar feature image is consistent with the target adjustment gear. If they are consistent, the gear adjustment is correct.

[0034] In this embodiment, the calculation expression for similarity comparison using Euclidean distance is: (4) In the above formula, is the Euclidean distance between the image feature value of the n-th feature image and the image feature value of the current putter image, m is the m-th pixel in the image, N is the total number of pixels in the image, is the image feature value of the mth pixel of the current push rod image, is the image feature value of the mth pixel of the feature image.

[0035] In a specific application embodiment, whenever the end of the gear shifting progress is detected, that is, the gear shifting is completed, it is also necessary to determine whether the gear is correctly shifted to the desired gear. Therefore, firstly, the image of the push rod when the gear shifting is completed is collected, and the push rod outline is extracted through grayscale processing and edge detection processing, and then the image feature value of each pixel point in the image is calculated by formula (1). In order to match the push rod image with each feature image in the feature image library, this embodiment uses the Euclidean distance to evaluate the similarity between images. By calculating the Euclidean distance value between the image feature value of the push rod image and each feature image in the feature image library , we can evaluate the similarity between the two. The closer the value is to 0, the more similar the two images are. At this time, the gear position corresponding to the feature image that is most similar to the push rod image is the current gear position. If the current gear position is consistent with the gear position to be adjusted, the gear adjustment is correct. Otherwise, the gear adjustment is wrong and needs to be re-adjusted.

[0036] In this embodiment, step S2 further includes: Whenever the gear is adjusted, the swing angle of the push rod is detected by the angle detection device, and the gear rotation volume of the gear adjustment mechanism is detected by the sound detection device to comprehensively judge whether the gear adjustment is completed. If the swing angle of the push rod is detected to be lower than the threshold and the gear rotation sound is continuously detected when the drive motor rotates, it indicates that the gear adjustment is completed; otherwise, it indicates that the push rod is separated from the gear adjustment button or the gear adjustment mechanism is operating abnormally; The swing angle of the current push rod collected by the angle detection device when the gear adjustment is completed is compared with the swing center angle of the push rod in the image of the corresponding gear in the feature image library. If the error between the two is less than the preset range, it indicates that the gear adjustment is correct.

[0037] In a specific application embodiment, due to unexpected factors such as the push rod being separated from the gear shifting button, the push rod may not be able to accurately push the gear shifting button to achieve the gear shifting operation when it swings at a certain angle. To this end, other information can be combined to further judge the gear shifting operation. The motor is connected to the push rod through the encoder disk, and the encoder disk detects the swing angle of the push rod. The main control device obtains the real-time information of the encoder disk, runs the preset control process (controls the push rod of the gear shifting mechanism to swing full stroke), and fuses the encoder disk with the gear position obtained through the push rod image for judgment. If the real-time information of the encoder disk matches the gear position information in the push rod image, it is judged that the push rod and the gear shifting button are not separated, otherwise it is judged to be separated, thereby improving the accuracy of gear position recognition. On the other hand, a sound detection device can also be added. During the gear shifting process, the gear of the gear shifting mechanism rotates and makes a sound. If the gear shifting mechanism makes a sound while the push rod motor rotates, it is judged that the gear shifting mechanism is operating normally, otherwise it is judged to be abnormal. At the same time, the change of the sound can be used to judge whether the current gear shifting process is completed.

[0038] By integrating the above two aspects, we can know the corresponding relationship between the swing angle of the push rod and the gear position (the actual situation of each pressure regulating device is slightly different, and this method can more accurately ensure the correspondence between the push rod and the gear position). If the posture of the push rod (the push rod image collected in real time), the driving force feedback, the swing angle detected by the encoder disk, and the sound signal of the gear shifting mechanism are changing, it indicates that the gear shifting mechanism is in the gear shifting process. If the above signals no longer change, it indicates that the gear shifting is completed. If one of the above signals is abnormal, it indicates that the push rod is detached from the gear shifting button, and a special person needs to be arranged for debugging and maintenance. After the above judgment, the gear shifting mechanism can start to control the push rod to switch between different gears. It can be understood that the angle detection equipment and the sound detection equipment can more accurately assist in judging the gear shifting progress. In addition, the comparison of the push rod swing angle detected by the angle detection equipment and the push rod swing angle in the feature image library can further help determine whether the gear shifted is accurate.

[0039] In this embodiment, the portable on-load transformer automatic voltage regulation method further includes: If the collected push rod image contains the gear display information of the loaded transformer, a feature image library of the gear display information under each gear is established, and when the gear is adjusted, a comprehensive judgment is made as to whether the gear adjustment is completed based on the resistance change and the gear display information collected in real time, and the current gear display information collected when the gear adjustment is completed is compared with the gear display information in the feature image library to determine whether the gear adjustment is correct.

[0040] In a specific application embodiment, the control panel of the on-load transformer will display the current gear position in a visual form (such as LED digital display). For example, when there are 17 gear positions, the current gear position is displayed with numbers 1-17. In this case, the gear position can be identified by using a more intuitive and efficient digital detection instead of the position change of the push rod. Specifically, the digital image of the gear position display of the on-load voltage regulator of the transformer from 1 to 17 is obtained through the high-definition camera on the device, and a feature model library and corresponding operation instructions are established and stored in the gear adjustment machine. The acquired feature model library is gray-scale processed and edge-detected, and the image feature value of each gear position display number is obtained by using formula (1). When the gear is adjusted, the image acquisition device collects the digital image of the gear position display in real time at regular intervals, and determines whether the gear position display number in the image changes at different times to determine whether it is currently in the gear adjustment process or the gear adjustment is completed. Of course, in order to make the gear adjustment progress judgment more accurate, the angle detection device and the sound detection device can also be used for fusion judgment. After the gear adjustment is completed, the similarity between the image feature value of the gear display number obtained at this time and the character image of each gear display information in the feature image library is calculated to evaluate their similarity. The closer the value is to 0, the more similar the two images are, that is, the more the recognized gear display number matches the character image in the feature image library, the current gear can be determined. For example, within a certain period of time (such as 15 seconds), if the gear is judged to have changed in real time through character image matching (when an upshift command is issued, the gear changes from a low gear to a high gear 1st gear; when a downshift command is issued, the gear changes from a high gear to a low gear 1st gear), the gear is judged to be correct, otherwise it is judged to be wrong.

[0041] If the gear adjustment is correct, the subsequent detection process (winding DC resistance test) will be executed; if the gear adjustment is inconsistent with the target gear, or it is detected that the current gear is not recognized or the gear adjustment mechanism is not reset, an alarm message is generated, the current adjustment operation is interrupted, and a secondary adjustment / fine-tuning is performed according to the settings until the gear is adjusted to the target gear.

[0042] In addition, if Figure 2 and Figure 4 As shown, the present invention also provides a portable on-load transformer automatic voltage regulating device, including: a gear adjustment mechanism, an image acquisition device and a main control device; The gear-shifting mechanism is installed on the on-load tap-changer of the on-load transformer and is used to perform gear-shifting operation on the gear-shifting knob on the on-load tap-changer control box; the gear-shifting mechanism includes a driving motor and a push rod, one end of the push rod is drivingly connected to the output shaft of the motor, and the other end is fixedly connected to the gear-shifting knob, so that the gear-shifting knob can be driven by the push rod to realize the gear-shifting operation; The image acquisition equipment includes a number of wireless cameras for acquiring images of the on-load tap changer control box and the push rods in the gear-shifting mechanism; The main control device shown includes a main controller, an image processing module and a display module that are communicatively connected to the gear shifting mechanism and the image acquisition device; the main controller is used to drive the push rod of the gear shifting mechanism according to the gear position to be shifted to drive the gear shifting knob to realize the gear shifting operation, judge whether the gear shifting is correct according to the real-time push rod image captured by the image acquisition device, prohibit the next operation and generate an alarm message when the gear position is not identified or the gear shifting mechanism is not reset; the image processing module is used to process and compare the collected push rod image of the gear shifting mechanism; the display module is used to present the gear shifting progress in real time.

[0043] In this embodiment, the portable on-load transformer automatic voltage regulating device further includes: an angle detection device and a sound detection device; The angle detection device includes an encoding disk, the two ends of which are respectively connected to the drive motor and the push rod, and are used to detect the swing angle of the push rod; The sound detection device is installed at the gear of the gear shifting mechanism and is used to detect the rotation volume of the gear of the gear shifting mechanism; the sound detection device includes one or more of a sound level meter, a microphone, and an acoustic sensor.

[0044] In a specific application embodiment, the automatic voltage regulating device mainly includes a gear adjustment mechanism, a wireless camera and a main control center. The gear adjustment mechanism is installed on the on-load tap changer and is used to perform a gear shifting operation on the gear adjustment knob on the on-load tap changer control box. There are multiple wireless cameras, and each wireless camera is used in conjunction with one of the gear adjustment machines.

[0045] The main control center is mainly used to control the gear shifting operation of the gear shifting machine according to the gear shifting mechanism image information obtained by the wireless camera. The main control center communicates with the first wireless communication module of the gear shifting mechanism through the second wireless communication module. The main control center mainly includes a main controller, an image processing module, and a second wireless communication module. In addition, the main control center also provides a user APP remote connection, allowing the operator to send operation control instructions through the main control center, and the gear shifting mechanism performs corresponding operations after receiving the operation instructions.

[0046] The gear-shifting mechanism mainly includes: a push rod driven by a motor, one end of the push rod is connected to the output shaft of the motor, and the other end of the push rod is fixedly connected to the gear-shifting knob, so that the push rod can drive the gear-shifting knob to achieve the gear-shifting operation. The gear-shifting mechanism also includes a controller and a first wireless communication module, and the controller is used to communicate with the first wireless communication module and control the operation of the motor. Figure 4 As shown, the gear adjustment mechanism further comprises a mechanical arm (1), a support module (2) for supporting the mechanical arm (1), a base (3) for supporting the overall structure, and a power supply module (not shown in the figure). The mechanical arm (1) is connected to a drive motor and a push rod, so that the push rod is placed in an appropriate position so that it can act on the gear adjustment knob to adjust the gear.

[0047] It should be noted that installing the gear shifter at the appropriate position on the on-load tap changer can ensure that all gear shift knobs can be operated when the push rod swings, and also ensure that the gear shift knobs in different positions have different postures when operating the gear shift knobs. One part of the push rod is outside the shell and is the visible part, and the other side is inside the shell and is the invisible part; when actually shooting the image, only the swing of the visible part of the push rod can be seen.

[0048] The image acquisition device usually adopts a wireless camera, which can realize remote transmission of the acquired video images. The wireless camera is mainly used to obtain the image of the on-load voltage regulator of the transformer (shooting the on-load voltage regulator from the outside); when the image acquisition device is installed, the observation direction is as perpendicular as possible to the swing direction of the push rod, and the image of the push rod is obtained at an orthogonal perspective.

[0049] The image recognition module, under the action of the main controller, processes the video image of the gear adjustment mechanism collected by the wireless camera to prepare to obtain the gear adjustment button currently operated by the push rod. The gear adjustment mechanism itself can be servo, or it can be driven by the image collected in real time by the image acquisition device.

[0050] The main control center sets the gear position to be adjusted according to the demand; the host drives the gear-adjusting mechanism to move according to the gear position to be adjusted (the driving action is feedback-free, and the host gives a travel instruction to make the gear-adjusting mechanism move. The specific form of the travel instruction is related to the structure of the gear-adjusting mechanism, and the specific travel of the travel instruction is related to the type of transformer / type of the transformer's on-load voltage regulating mechanism); The automatic voltage regulating device uses the current rotation method to adapt the push rod. When the push rod is fully pushed out, the push rod automatically retracts and will not continue to push. When the push rod hits an object and remains stationary for about 0.5 seconds, the current direction changes, and the push rod automatically retracts and will not continue to push. When the button is fully pressed to the bottom, the push rod will remain stationary for 0.5 seconds after being pressed to the bottom, the current direction changes, and the push rod automatically retracts to avoid damage to the equipment.

[0051] The tester sends a gear adjustment instruction through the remote control device, and the signal is transmitted to the gear adjustment mechanism through the wireless communication module. After receiving the instruction, the gear adjustment mechanism performs corresponding operations according to the instruction content, such as starting the gear adjustment program or adjusting the gear position. After each gear adjustment operation, the gear adjustment mechanism will feedback the execution result to the remote control device through the wireless communication module. The operator can monitor the progress of the gear adjustment in real time through the interface and make necessary adjustments or stop the operation. In addition, in order to ensure the safety of operation, the remote control module is equipped with a variety of anti-misoperation measures, such as prohibiting the start of the next operation when the gear position is not identified or the gear adjustment machine is not reset. In addition, the system has an alarm function beyond the communication range to ensure the effectiveness and timeliness of the control signal.

[0052] Compared with the prior art, the advantages of the present invention are: 1. Improve operational efficiency: The present invention realizes the full automation of the transformer gear adjustment process through the automatic voltage regulating device. Operators do not need to adjust gears manually, which reduces tedious manual operations and greatly improves work efficiency. Especially when performing multiple rounds of gear adjustment tests, the automated device can complete the operation in a relatively short time, saving a lot of manpower and time.

[0053] 2. Enhanced safety and reliability: Through remote control equipment, operators can adjust gears at a safe distance, avoiding the risk of direct contact with high-voltage equipment, significantly improving the safety of operation; the image recognition module double-confirms the gear position before and after the gear adjustment to ensure the accuracy of each gear adjustment operation, reducing the risk of misoperation due to gear position recognition errors, and the system can operate reliably even in complex environments.

[0054] 3. High image recognition accuracy: The present invention adopts advanced image recognition algorithm, monitors the transformer gear position or push rod image in real time through the camera, calculates the Euclidean distance between the image feature value and the feature image library, and determines the current gear position by judging the matching situation between the recognized image character or push rod image and the digital character / push rod image position of the corresponding gear feature image library. Whether in insufficient light or limited angle, the system can provide high-precision gear position recognition results.

[0055] 4. Strong adaptability: The image recognition algorithm design of the present invention has good versatility and can adapt to different models and types of on-load tap changers. Through the fusion information such as the push rod posture, driving force feedback, encoder disk detection swing angle, sound signal and gear data obtained by video image, the system can stably and accurately identify the gear in various operating environments.

[0056] 5. Reduce labor costs: Due to the high degree of automation in the file transfer process, testers do not need to be responsible for the file transfer operation, which significantly reduces the dependence on human resources and reduces labor costs. The remote control module provides a simple and intuitive operation interface, and operators can easily control the entire file transfer process without complex training, reducing the difficulty of operation.

[0057] 6. Efficient data recording and processing: The system can record the DC resistance test data before and after each gear adjustment in real time and automatically generate a test report. The automatic recording of data avoids omissions and errors in manual recording and improves the accuracy and completeness of the data. The recorded data is stored in a standard format to facilitate subsequent analysis and processing. Combined with data analysis tools, the gear adjustment strategy can be further optimized to improve the scientificity and accuracy of the test process.

[0058] 7. Good versatility and applicability: The present invention adopts a modular design and can be applied to various types of on-load tap changers. Different modules can be configured and adjusted according to actual needs, which has strong flexibility. The device is not only suitable for direct resistance testing of transformers, but can also be used in other power equipment that requires gear adjustment and remote control, and has broad application prospects.

[0059] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A portable on-load transformer automatic voltage regulation method, characterized in that: include: S1, collecting images corresponding to the push rod when the gear adjustment knob of the on-load transformer is in each different gear position during the gear adjustment process when the push rod of the gear adjustment mechanism pushes the gear adjustment knob of the on-load transformer to establish a feature image library of the push rod images in each gear position; S2, whenever the gear is adjusted, a comprehensive judgment is made as to whether the gear adjustment is completed based on the change in the resistance of the push rod swinging when the gear adjustment knob is pushed and the push rod image collected in real time, and the current push rod image collected when the gear adjustment is completed is compared with the image of the corresponding gear in the feature image library to determine whether the gear adjustment is correct.

2. The portable on-load transformer automatic voltage regulation method according to claim 1 is characterized in that: In step S1, the step of establishing a feature image library of the position of the push rod in each gear position includes: Grayscale each collected image; The grayscale processed image is subjected to edge detection processing, and the image feature value of the image and the swing center angle of the putter are calculated based on the image after the edge detection processing.

3. The portable on-load transformer automatic voltage regulation method according to claim 2 is characterized in that: The calculation expression of the image feature value is: ， In the above formula, is the image feature value of the mth pixel in the image, are the horizontal and vertical coordinates of the mth pixel in the image, respectively. is the gray value of the mth pixel in the image; The calculation expression of the swing center angle of the push rod is: ， In the above formula, is the swing center angle of the push rod, are the horizontal and vertical axis positions of the swing center of the push rod, are the horizontal and vertical axis positions of the axis skeleton of the putter in the i-th putter image, respectively. is the angle of the axis skeleton of the putter in the i-th putter image, and n is the total number of putter images.

4. The portable on-load transformer automatic voltage regulation method according to any one of claims 1 to 3, characterized in that: In step S2, comprehensively judging whether the gear shifting is completed according to the change in the resistance of the push rod swinging when the gear shifting knob is pushed and the push rod image collected in real time includes: If the resistance to the swing of the push rod suddenly increases or decreases, it indicates that the gear shifting process has started or ended; if the resistance remains stable, it indicates that the gear shifting is continuing; if the resistance is zero, it indicates that the gear shifting has been completed or no gear shifting operation has been performed; If the position of the push rod in the collected push rod image continues to change, it indicates that the gear is being adjusted; if the position of the push rod does not change in the push rod image within the preset range, it indicates that the gear adjustment is completed.

5. The portable on-load transformer automatic voltage regulation method according to any one of claims 1 to 3, characterized in that: In step S2, the current push rod image collected when the gear adjustment is completed is compared with the image of the corresponding gear in the feature image library to determine whether the gear adjustment is correct, including: Calculate the image feature value of the current push rod image after grayscale processing and edge detection processing when the gear adjustment is completed, and perform similarity comparison with the image feature value of the feature image corresponding to each gear in the feature image library through Euclidean distance to obtain the most similar feature image, and judge whether the gear corresponding to the most similar feature image is consistent with the target adjustment gear. If they are consistent, the gear adjustment is correct.

6. The portable on-load transformer automatic voltage regulation method according to claim 5, characterized in that: The calculation expression for similarity comparison using Euclidean distance is: ， In the above formula, is the Euclidean distance between the image feature value of the n-th feature image and the image feature value of the current putter image, m is the m-th pixel in the image, N is the total number of pixels in the image, is the image feature value of the mth pixel of the current putter image, is the image feature value of the mth pixel of the feature image.

7. The portable on-load transformer automatic voltage regulation method according to any one of claims 1 to 3, characterized in that: Step S2 also includes: Whenever the gear is adjusted, the swing angle of the push rod is detected by the angle detection device, and the gear rotation volume of the gear adjustment mechanism is detected by the sound detection device to comprehensively judge whether the gear adjustment is completed. If the swing angle of the push rod is detected to be lower than the threshold and the gear rotation sound is continuously detected when the drive motor rotates, it indicates that the gear adjustment is completed; otherwise, it indicates that the push rod is separated from the gear adjustment button or the gear adjustment mechanism operates abnormally; The swing angle of the current push rod collected by the angle detection device when the gear adjustment is completed is compared with the swing center angle of the push rod in the image of the corresponding gear in the feature image library. If the error between the two is less than the preset range, it indicates that the gear adjustment is correct.

8. The portable on-load transformer automatic voltage regulation method according to claim 1, characterized in that: The portable on-load transformer automatic voltage regulation method also includes: If the collected push rod image contains the gear display information of the loaded transformer, a feature image library of the gear display information under each gear is established, and when the gear is adjusted, a comprehensive judgment is made as to whether the gear adjustment is completed based on the resistance change and the gear display information collected in real time, and the current gear display information collected when the gear adjustment is completed is compared with the gear display information in the feature image library to determine whether the gear adjustment is correct.

9. A portable automatic voltage regulating device for an on-load transformer, characterized in that: include: File adjustment mechanism, image acquisition equipment and main control equipment; The gear-shifting mechanism is installed on the on-load tap changer of the on-load transformer and is used to perform a gear-shifting operation on the gear-shifting knob on the on-load tap changer control box; the gear-shifting mechanism includes a driving motor and a push rod, one end of the push rod is drivingly connected to the output shaft of the motor, and the other end is fixedly connected to the gear-shifting knob, so that the push rod can drive the gear-shifting knob to realize the gear-shifting operation; The image acquisition device includes a number of wireless cameras for acquiring images of the on-load tap changer control box and the push rod in the gear-shifting mechanism; The main control device shown includes a main controller, an image processing module and a display module that are communicatively connected to the gear shifting mechanism and the image acquisition device; the main controller is used to drive the push rod of the gear shifting mechanism according to the gear position to be shifted to drive the gear shifting knob to realize the gear shifting operation, judge whether the gear shifting is correct according to the real-time push rod image captured by the image acquisition device, prohibit the next operation and generate an alarm message when the gear position is not identified or the gear shifting mechanism is not reset; the image processing module is used to process and compare the collected push rod image of the gear shifting mechanism; the display module is used to present the gear shifting progress in real time.

10. The portable on-load transformer automatic voltage regulating device according to claim 9, characterized in that: The portable on-load transformer automatic voltage regulating device also includes: angle detection equipment and sound detection equipment; The angle detection device comprises an encoding disc, the two ends of which are respectively connected to the driving motor and the push rod, and are used to detect the swing angle of the push rod; The sound detection device is installed at the gear of the gear shifting mechanism and is used to detect the rotation volume of the gear of the gear shifting mechanism; the sound detection device includes one or more of a sound level meter, a microphone, and an acoustic sensor.

Images