Error elimination method for detecting opening and closing speed of high voltage circuit breaker in transformer substation

Abstract

The embodiment of the application provides a substation high-voltage circuit breaker opening and closing speed detection error elimination method, and belongs to the technical field of substation high-voltage circuit breaker opening and closing speed detection. The method comprises the following steps: constructing a world coordinate system and a pixel coordinate system of a checkerboard; obtaining the resolution and the maximum range of the high-voltage circuit breaker movement speed; the substation high-voltage circuit breaker opening and closing speed detection error elimination method provided by the application sets a checkerboard on the moving contact of the high-voltage circuit breaker, constructs the world coordinate system and the pixel coordinate system of the checkerboard, calculates the resolution and the maximum range of the high-voltage circuit breaker movement speed, then calculates the speed error of the high-voltage circuit breaker according to the resolution and the maximum range, finally calculates the actual opening and closing movement speed according to the speed error, so that the accurate measurement of the high-voltage circuit breaker movement speed can be realized, the reliability is higher, and the method is more convenient.

Description

Technical Field

[0001] This invention relates to the field of substation high-voltage circuit breaker opening and closing speed detection technology, specifically to an error elimination method for detecting the opening and closing speed of substation high-voltage circuit breakers. Background Technology

[0002] A substation is an assembly of equipment used to disconnect or connect, change or adjust voltage. In a power system, a substation is the junction point for power transmission and distribution. Substations are mainly classified as: step-up substations, main grid substations, secondary substations, and distribution substations. Among them, those with voltages lower than the switching or connection voltage include high-voltage circuit breakers.

[0003] High-voltage circuit breaker (HVBC) maintenance is one of the most important procedures in substation operation and maintenance, as it bears the heavy responsibility of ensuring the safe and reliable operation of the power grid. During HVBC maintenance, it is generally necessary to test its opening and closing speed characteristics. Existing speed testing methods include using high-speed cameras to photograph the movement of target points on the operating contacts of the HVBC to obtain its trajectory and speed characteristics. However, due to the rapid movement of the operating contacts, high-speed cameras suffer from pixel-level errors in identifying target points, leading to certain errors in the opening and closing speed detection and affecting the assessment of the HVBC maintenance.

[0004] In the process of realizing this invention, the inventors of this application discovered that the above-mentioned solutions in the prior art have the defect that errors in the speed detection process affect the judgment of high-voltage circuit breaker maintenance. Summary of the Invention

[0005] The purpose of this invention is to provide an error elimination method for detecting the opening and closing speed of high-voltage circuit breakers in substations. This error elimination method has the function of eliminating pixel errors in the images recognized by high-speed cameras.

[0006] To achieve the above objectives, embodiments of the present invention provide a method for eliminating errors in the detection of the opening and closing speed of high-voltage circuit breakers in substations, comprising:

[0007] Construct the world coordinate system and pixel coordinate system of the chessboard grid;

[0008] To obtain the resolution and maximum range of the high-voltage circuit breaker's movement speed;

[0009] The speed error of the high-voltage circuit breaker is calculated based on the resolution and maximum range of the high-voltage circuit breaker's movement speed.

[0010] The operating speed of the high-voltage circuit breaker for opening and closing is obtained based on the speed error.

[0011] Optionally, obtaining the resolution and maximum range of the high-voltage circuit breaker's operating speed includes:

[0012] The speed at which the high-voltage circuit breaker moves between two frames is calculated according to formula (1).

[0013]

[0014] Where V is the movement speed of the high-voltage circuit breaker between two frames, L is the number of pixels in the width of the checkerboard in the pixel coordinate system, S is the number of pixels in the travel distance of the high-voltage circuit breaker between two frames, f is the frame rate, and l is the width of the checkerboard.

[0015] The resolution corresponding to the motion speed is calculated according to formula (2).

[0016]

[0017] Among them, R e The resolution corresponding to the motion speed.

[0018] Optionally, obtaining the resolution and maximum range of the high-voltage circuit breaker's operating speed also includes:

[0019] The maximum range of the motion speed is calculated according to formula (3).

[0020] V max =s·f, (3)

[0021] Among them, V max s represents the maximum range of the movement speed, and s represents the total stroke of the high-voltage circuit breaker.

[0022] Optionally, calculating the speed error of the high-voltage circuit breaker based on its operating speed resolution and maximum range includes:

[0023] The error propagation formula for the speed of the high-speed camera is obtained according to formula (4).

[0024]

[0025] Where Δy is the error propagation value of the high-speed camera speed, and Δx n Let y = f(x1, x2, ..., xn) be the difference between the x-axis coordinates of the nth pixel and the (n-1)th pixel. n );

[0026] The absolute error of the high-speed camera speed is calculated according to formula (5).

[0027]

[0028] Among them, E aΔl is the absolute error of the speed of the high-speed camera, ΔS is the pixel error of the width of the checkerboard, and ΔL is the pixel error of the width of the checkerboard.

[0029] Optionally, the absolute error of the high-speed camera speed calculated according to formula (5) includes:

[0030] The functional relationship between the number of pixels in the high-voltage circuit breaker travel between two frames and the frame rate is obtained according to formula (6).

[0031]

[0032] Where α is the first proportionality coefficient.

[0033] Optionally, calculating the absolute error of the high-speed camera speed according to formula (5) further includes:

[0034] The functional relationship between the number of pixels on the width of the checkerboard in the pixel coordinate system and the resolution of the high-speed camera can be obtained according to formula (7).

[0035] L=β·P, (7)

[0036] Where β is the second scaling factor and P is the camera resolution.

[0037] Optionally, the error elimination method further includes:

[0038] Substituting formula (7) into formula (2), the resolution of the motion speed is obtained as shown in formula (8).

[0039]

[0040] Among them, R e The resolution corresponding to the motion speed.

[0041] Optionally, the error elimination method further includes:

[0042] Substituting equations (6) and (7) into equation (5), the absolute error of the high-speed camera speed is obtained as shown in equation (9).

[0043]

[0044] Among them, E a This represents the absolute error of the speed of the high-speed camera.

[0045] On the other hand, the present invention also provides a computer-readable storage medium storing instructions for being read by a machine to cause the machine to perform any of the error elimination methods described above.

[0046] Through the above technical solution, the error elimination method for detecting the opening and closing speed of high-voltage circuit breakers in substations provided by the present invention sets a checkerboard pattern on the operating contacts of the high-voltage circuit breaker and constructs a world coordinate system and a pixel coordinate system for the checkerboard pattern. It calculates the resolution and maximum range of the high-voltage circuit breaker's movement speed, then calculates the speed error of the high-voltage circuit breaker based on the resolution and maximum range, and finally calculates the actual opening and closing speed based on the speed error. This enables accurate measurement of the operating speed of the high-voltage circuit breaker, which is more reliable and more convenient.

[0047] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0048] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0049] Figure 1 This is a flowchart of an error elimination method for detecting the opening and closing speed of a substation high-voltage circuit breaker according to an embodiment of the present invention;

[0050] Figure 2 This is a flowchart of obtaining the maximum range of motion speed in an error elimination method for detecting the opening and closing speed of a substation high-voltage circuit breaker according to an embodiment of the present invention.

[0051] Figure 3 This is a flowchart of calculating the absolute error in an error elimination method for detecting the opening and closing speed of a substation high-voltage circuit breaker according to an embodiment of the present invention. Detailed Implementation

[0052] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0053] Figure 1 This is a flowchart of an error elimination method for detecting the opening and closing speed of a substation high-voltage circuit breaker according to an embodiment of the present invention. Figure 1 In this context, the error elimination method may include:

[0054] In step S10, the world coordinate system and pixel coordinate system of the checkerboard pattern are constructed. Specifically, before the opening and closing speed of the high-voltage circuit breaker needs to be detected, the checkerboard pattern is pasted and set on the operating contact of the high-voltage circuit breaker, and the checkerboard pattern is placed inside the frame of the high-speed camera. The world coordinate system and pixel coordinate system of the checkerboard pattern are constructed based on the frame of the high-speed camera.

[0055] In step S11, the resolution and maximum range of the high-voltage circuit breaker's movement speed are obtained. This requires calculating the resolution and maximum range of the high-voltage circuit breaker's movement speed based on parameters such as the pixel size of the chessboard and the width of the chessboard squares.

[0056] In step S12, the speed error of the high-voltage circuit breaker is calculated based on the resolution and maximum range of the high-voltage circuit breaker's movement speed. Specifically, after obtaining the resolution and maximum range of the high-voltage circuit breaker's movement speed, the measurement error of the high-speed camera during the opening and closing process of the high-voltage circuit breaker is calculated based on these values.

[0057] In step S13, the operating speed of the high-voltage circuit breaker is obtained based on the speed error. The actual values ​​of the high-voltage circuit breaker's opening and closing speeds can be obtained from the measured operating speed and measurement error, facilitating subsequent diagnosis of the high-voltage circuit breaker's opening and closing speed characteristics.

[0058] In steps S10 to S13, a checkerboard pattern is first installed on the actuating contact, and the world coordinate system and pixel coordinate system of the checkerboard pattern are constructed. The resolution and maximum range of the high-voltage circuit breaker's movement speed are calculated, and the speed error of the high-voltage circuit breaker is obtained based on these values. Based on this speed error, the actual operating speed of the high-voltage circuit breaker's opening and closing can be calculated, thus enabling an accurate judgment of the speed characteristics of the high-voltage circuit breaker's opening and closing.

[0059] Traditional methods for detecting the opening and closing speed of high-voltage circuit breakers involve using a high-speed camera to capture images of the movement of target points on the operating contacts, obtaining their trajectory and speed characteristics. However, due to the rapid movement of the operating contacts, the high-speed camera's identification of target points suffers from pixel-level errors, leading to inaccuracies in the opening and closing speed detection and affecting the assessment of the high-voltage circuit breaker's maintenance. In this embodiment of the invention, a method that acquires the opening and closing speed error of the high-voltage circuit breaker enables precise measurement of its operating speed, offering higher reliability and greater convenience.

[0060] In this embodiment of the invention, in order to obtain the resolution and maximum range of the high-voltage circuit breaker's movement speed, it is also necessary to calculate the pixels and width of the checkerboard grid. Specific steps can be as follows: Figure 2 As shown. Specifically, in Figure 2 In this context, the error elimination method may include:

[0061] In step S20, the movement speed of the high-voltage circuit breaker between two frames is calculated according to formula (1).

[0062]

[0063] Where V is the movement speed of the high-voltage circuit breaker between two frames, L is the number of pixels in the width of the checkerboard in the pixel coordinate system, S is the number of pixels in the travel distance of the high-voltage circuit breaker between two frames, f is the frame rate, and l is the width of the checkerboard.

[0064] In step S21, the resolution corresponding to the motion speed is calculated according to formula (2).

[0065]

[0066] Among them, R e This represents the resolution corresponding to the motion speed.

[0067] In step S22, the maximum range of motion speed is calculated according to formula (3).

[0068] V max =s·f, (3)

[0069] Among them, V max s represents the maximum range of the moving speed, and s represents the total stroke of the high-voltage circuit breaker.

[0070] In this embodiment of the invention, in order to calculate the speed error of the high-voltage circuit breaker, it is also necessary to calculate the resolution and maximum range of the high-voltage circuit breaker's movement speed. Specific steps can be as follows: Figure 3 As shown. Specifically, in Figure 3 In this context, the error elimination method may include:

[0071] In step S30, the error propagation formula for the high-speed camera speed is obtained according to formula (4).

[0072]

[0073] Where Δy is the error propagation value of the high-speed camera velocity, and Δx n Let y = f(x1, x2, ..., xn) be the difference between the x-axis coordinates of the nth pixel and the (n-1)th pixel. n ).

[0074] In step S31, the absolute error of the high-speed camera speed is calculated according to formula (5).

[0075]

[0076] Among them, E aLet Δl be the absolute error of the high-speed camera speed, ΔS be the pixel error of the high-voltage circuit breaker travel between two frames of the checkerboard, and ΔL be the pixel error of the checkerboard width. Specifically, the functional relationship between the pixel count of the high-voltage circuit breaker travel between two frames and the frame rate can be obtained from formula (6).

[0077]

[0078] Where α is the first proportionality coefficient.

[0079] The functional relationship between the number of pixels on the width of the checkerboard grid in the pixel coordinate system and the resolution of the high-speed camera can be derived from formula (7).

[0080] L=β·P, (7)

[0081] Where β is the second scaling factor and P is the camera resolution.

[0082] Substituting equation (7) into equation (2), we can obtain the resolution of the motion velocity as shown in equation (8).

[0083]

[0084] Among them, R e This represents the resolution corresponding to the motion speed.

[0085] Substituting equations (6) and (7) into equation (5), we obtain the absolute error of the high-speed camera speed as shown in equation (9).

[0086]

[0087] Among them, E a This represents the absolute error of the high-speed camera's speed. Specifically, the speed error is mainly related to the measurement error of the checkerboard width in the world coordinate system, the checkerboard pixel width in the pixel coordinate system, and the circuit breaker travel. As shown in formula (9), increasing the camera's resolution and frame rate can improve the measurement accuracy. The travel of a typical circuit breaker is 5-20cm, and the maximum speed is generally no more than 10m / s. When l = 1mm, L = 10pixel, f = 1000FPS, the highest resolution of V is: R e =0.1m / s, the maximum range of V is: V max =100m / s.

[0088] On the other hand, the present invention also provides a computer-readable storage medium storing instructions for being read by a machine to cause the machine to perform any of the error elimination methods described above.

[0089] Through the above technical solution, the error elimination method for detecting the opening and closing speed of high-voltage circuit breakers in substations provided by the present invention sets a checkerboard pattern on the operating contacts of the high-voltage circuit breaker and constructs a world coordinate system and a pixel coordinate system for the checkerboard pattern. It calculates the resolution and maximum range of the high-voltage circuit breaker's movement speed, then calculates the speed error of the high-voltage circuit breaker based on the resolution and maximum range, and finally calculates the actual opening and closing speed based on the speed error. This enables accurate measurement of the operating speed of the high-voltage circuit breaker, which is more reliable and more convenient.

[0090] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0091] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0092] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0093] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1The steps of the function specified in one or more boxes.

[0094] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0095] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, like read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0096] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0097] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0098] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for eliminating errors in the detection of the opening and closing speed of a high-voltage circuit breaker in a substation, characterized in that, include: Construct the world coordinate system and pixel coordinate system of the chessboard grid; To obtain the resolution and maximum range of the high-voltage circuit breaker's movement speed; The speed error of the high-voltage circuit breaker is calculated based on the resolution and maximum range of the high-voltage circuit breaker's movement speed. The operating speed of the high-voltage circuit breaker for opening and closing is obtained based on the speed error. The resolution and maximum range for obtaining the operating speed of a high-voltage circuit breaker include: The speed at which the high-voltage circuit breaker moves between two frames is calculated according to formula (1). ，（1） in, The speed at which the high-voltage circuit breaker moves between two frames. This represents the number of pixels across the width of the checkerboard grid in the pixel coordinate system. This represents the number of pixels representing the high-voltage circuit breaker travel distance between two frames. For frame rate, The width of the chessboard square; Calculate the resolution corresponding to the motion speed according to formula (2). ，（2） in, The resolution corresponding to the motion speed; The maximum range of the motion speed is calculated according to formula (3). ，（3） in, This is the maximum range of the stated speed of motion. This refers to the total stroke of the high-voltage circuit breaker; The speed error of the high-voltage circuit breaker is calculated based on its speed resolution and maximum range, including: The error propagation formula for the speed of the high-speed camera is obtained according to formula (4). ，（4） in, This is the error propagation value for the speed of the high-speed camera. For the first The sum of the pixels is the first pixel. The difference in x-axis coordinates of pixels, ; The absolute error of the high-speed camera speed is calculated according to formula (5). ，（5） in, The absolute error of the speed of the high-speed camera is given. This is the width error value of the chessboard grid. This refers to the pixel error value of the high-voltage circuit breaker travel between two frames of the chessboard pattern. This is the pixel error value on the width of the chessboard grid.

2. The error elimination method according to claim 1, characterized in that, The absolute error of the high-speed camera speed calculated according to formula (5) includes: According to formula (6), the functional relationship between the number of pixels of the high-voltage circuit breaker travel between two frames and the frame rate can be obtained. ，（6） in, This is the first proportionality coefficient.

3. The error elimination method according to claim 2, characterized in that, The absolute error in calculating the speed of the high-speed camera according to formula (5) also includes: The functional relationship between the number of pixels on the width of the checkerboard in the pixel coordinate system and the resolution of the high-speed camera can be obtained according to formula (7). ，（7） in, This is the second proportionality coefficient. This refers to the camera resolution.

4. The error elimination method according to claim 3, characterized in that, The error elimination method further includes: Substituting formula (7) into formula (2), the resolution of the motion speed is obtained as shown in formula (8). ，（8） in, The resolution corresponding to the motion speed.

5. The error elimination method according to claim 3, characterized in that, The error elimination method further includes: Substituting equations (6) and (7) into equation (5), the absolute error of the high-speed camera speed is obtained as shown in equation (9). ，（9） in, This represents the absolute error of the speed of the high-speed camera.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that are read by a machine to cause the machine to perform the error elimination method as described in any one of claims 1 to 5.

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