Vacuum circuit breaker double-channel electrical life on-line monitoring method and device

Abstract

The invention discloses a vacuum circuit breaker double-channel electrical life on-line monitoring method and device, and the method comprises the steps: S1, collecting the breaking current data of an electrical parameter channel main loop and a digital image of the electrical wear condition of a contact in parallel in real time in the opening operation process of a circuit breaker, and carrying out the preprocessing; s2, based on a relative electrical life method, calculating the residual relative electrical life of the circuit breaker according to the preprocessed breaking current data; based on a contact electrical wear degree image recognition method, according to the preprocessed digital image data, quantitatively evaluating an actual physical wear state indication angle of the contact; s3, comprehensively calculating the residual electrical life of the circuit breaker based on the residual relative electrical life of the circuit breaker and the actual physical wear state indication angle of the contact; s4, judging whether the residual electrical life exceeds an alarm threshold value or not, if so, sending an alarm signal, otherwise, returning to the step S1; the relative electrical life method and the image recognition technology are adopted, and the online monitoring precision and reliability of the electrical life of the circuit breaker are improved.

Description

Technical Field

[0001] This invention relates to the field of vacuum circuit breaker technology, and more specifically to a method and device for online monitoring of the electrical life of a dual-channel vacuum circuit breaker. Background Technology

[0002] With increasingly stringent environmental protection requirements and the upgrading of vacuum technology, vacuum circuit breakers have gradually become the core protection device of modern power systems, and the life monitoring of vacuum circuit breakers is extremely important. The life of a vacuum circuit breaker is limited by its storage life, mechanical life, and electrical life, among which the electrical life is the shortest and plays a decisive role.

[0003] Currently, the main methods for assessing the electrical life of circuit breakers include the cumulative breaking current method, the breaking current weighted method, the cumulative ablation factor method, and the more widely used N-based method. k -I ki The relative electrical life method of life curves; among them, the cumulative breaking current method and the breaking current weighted method can only indirectly evaluate the electrical life of the circuit breaker. The cumulative erosion factor method is prone to causing the circuit breaker to be repaired or replaced prematurely before the electrical life is exhausted. For vacuum circuit breakers, the method based on N is more suitable. k -I ki The relative electrical lifetime method of lifetime curves.

[0004] However, when a vacuum circuit breaker rapidly interrupts a short-circuit current, it generates an extremely strong electric arc. The degree of reduction in contact metal material and shape change caused by the arc burning on the contact surface is uncertain, leading to deviations in the results of the single circuit breaker electrical life monitoring method.

[0005] Therefore, how to improve the reliability of electrical life monitoring of vacuum circuit breakers and avoid the risk of failure of a single method, so as to prevent circuit breaker failure accidents caused by the exhaustion of electrical life or the failure to detect serious contact abnormalities, and reduce unplanned downtime losses, is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a method and device for online monitoring of the electrical life of a dual-channel vacuum circuit breaker, which integrates multi-source information to monitor the electrical life of the circuit breaker online, aiming to make up for the shortcomings of the prior art in that the evaluation results may be biased or have the risk of failure.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for online monitoring of the electrical life of a dual-channel vacuum circuit breaker includes the following steps:

[0009] S1. During the circuit breaker tripping operation, the breaking current data and contact wear condition digital image data of the main circuit of the electrical parameter channel are collected in real time and in parallel, and preprocessed.

[0010] S2. Based on the relative electrical life method, calculate the remaining relative electrical life of the circuit breaker according to the pre-processed breaking current data; based on the contact electrical wear degree image recognition method, quantitatively evaluate the actual physical wear state indicator angle of the contacts according to the pre-processed digital image data.

[0011] S3. Calculate the remaining electrical life of the circuit breaker based on the remaining relative electrical life of the circuit breaker and the actual physical wear state indication angle of the contacts.

[0012] S4. Determine whether the remaining battery life exceeds the alarm threshold. If it does, issue an alarm signal; otherwise, return to step S1.

[0013] Preferably, the specific details for calculating the remaining relative electrical life of the circuit breaker include:

[0014] Step 1: Conduct a breaking test on the monitored circuit breaker, and derive the empirical formula for the electrical life of the circuit breaker, N, based on the experimental data and the contact loss law. k -I ki Lifetime curve;

[0015] Step 2: Obtain the breaking current value I during circuit breaker operation. ki According to N k -I ki Lifetime curve, obtain the breaking current I ki The relative number of interruptions N of the lower circuit breaker k ;

[0016] Step 3: Calculate the breaking current I based on the relative number of breaking cycles. ki The relative electrical wear Q of the contacts corresponding to a single interruption k :

[0017] Step 4: Based on the relative electrical wear Q of the contacts corresponding to a single interruption. k Given the relative electrical life L0 of the circuit breaker contacts, calculate the remaining relative electrical life L after each interruption of the circuit breaker.

[0018] Preferably, the relative electrical life of a brand-new circuit breaker or a circuit breaker after major repair is set to 1, and the relative electrical wear of the contacts corresponding to a single interruption is Q. k for:

[0019]

[0020] Where, N k The breaking current I ki The relative number of interruptions N of the lower circuit breaker k ;

[0021] The remaining relative electrical life L of the circuit breaker after each interruption is:

[0022] L=L0-∑Q k

[0023] Where L0 is the relative electrical life of the circuit breaker contacts, 0≤L0≤1.

[0024] Preferably, the specific content of the indicator angle for quantitatively evaluating the actual physical wear state of the contact is as follows:

[0025] Step 1: Use an industrial camera to capture images of the contact wear instrument at fixed positions at regular intervals, and perform preprocessing, including grayscale conversion and noise reduction.

[0026] Step 2: Use Hough circle transform to detect the dial, and use edge detection and Hough line transform to detect the pointer profile, and determine the pointer angle θ. raw ;

[0027] Step 3: Convert the pointer angle to an angle in a specific coordinate system, with the center of the dial as the origin and the 0 mark as the 0-degree reference.

[0028] Step 4: Normalize the converted angle to obtain the contact wear indicator angle θ.

[0029] Preferably, the method for comprehensively calculating the remaining electrical life of the circuit breaker in step S3 is as follows:

[0030] L r =k l L+k θ θ

[0031] Where, k l k is the influence factor of the theoretical remaining relative electrical lifetime result L. θ The influencing factor is the result θ indicating the actual physical wear state of the contact.

[0032] A dual-channel online monitoring system for the electrical life of a vacuum circuit breaker, based on the aforementioned method for online monitoring of the electrical life of a dual-channel vacuum circuit breaker, includes: an electrical parameter acquisition module, a visible light camera, a relative electrical life calculation module, a contact wear degree instrument, an image recognition module, a comprehensive calculation module, and an alarm module;

[0033] The electrical parameter acquisition module is used to acquire the breaking current data of the main circuit of the electrical parameter channel in real time during the circuit breaker tripping operation.

[0034] A contact wear gauge is used to indicate the electrical wear condition of the contacts.

[0035] A visible light camera is used in parallel with the electrical parameter acquisition module to acquire digital image data of contact electrical wear.

[0036] The relative electrical life calculation module is used to calculate the remaining relative electrical life of the circuit breaker based on the pre-processed breaking current data using the relative electrical life method.

[0037] The image recognition module is used for image recognition methods based on the degree of electrical wear of contacts. Based on the preprocessed digital image data, it quantitatively evaluates the actual physical wear state of the contacts and indicates the angle.

[0038] The comprehensive calculation module is used to comprehensively calculate the remaining electrical life of the circuit breaker based on the remaining relative electrical life of the circuit breaker and the actual physical wear state indication angle of the contacts.

[0039] The alarm module is used to determine whether the remaining battery life exceeds the alarm threshold. If it does, an alarm signal is issued.

[0040] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the aforementioned method for online monitoring of the dual-channel electrical life of a vacuum circuit breaker.

[0041] A processing terminal includes a memory and a processor. The memory stores a computer program that can run on the processor. When the processor executes the computer program, it implements the aforementioned method for online monitoring of the dual-channel electrical life of a vacuum circuit breaker.

[0042] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a method and device for online monitoring of the electrical life of a dual-channel vacuum circuit breaker. By employing the relative electrical life method and image recognition technology to monitor the electrical life of the circuit breaker online, the accuracy and reliability of the electrical life assessment of the vacuum circuit breaker are significantly improved. Specifically:

[0043] The theoretical electrical wear calculation based on the curve outputs the remaining relative life value in real time. Simultaneously, a visible light camera is used to capture the position of the contact wear indicator pointer. Through dual-channel data dynamic calibration, the comprehensive error can be minimized. When the comprehensive evaluation result exceeds the alarm threshold, the system immediately triggers an abnormal alarm, effectively preventing the risk of failure of the interrupting current signal or abnormal burning. In addition, this invention replaces manual inspection with non-disassembly monitoring, maximizing the life of the equipment and combining high accuracy with high economy. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0045] Figure 1A schematic diagram of an online monitoring method for the dual-channel electrical life of a vacuum circuit breaker provided by the present invention;

[0046] Figure 2 The circuit breaker N provided by the present invention k -I ki Lifetime curve diagram;

[0047] Figure 3 A schematic diagram of the circuit breaker contact wear level instrument provided by the present invention. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] Embodiment 1 of this invention discloses an online monitoring method for the dual-channel electrical life of a vacuum circuit breaker, such as... Figure 1 This includes the following steps:

[0050] S1. During the circuit breaker tripping operation, the breaking current data and contact wear condition digital image data of the main circuit of the electrical parameter channel are collected in real time and in parallel, and preprocessed.

[0051] S2. Based on the relative electrical life method, calculate the remaining relative electrical life of the circuit breaker according to the pre-processed breaking current data; based on the contact electrical wear degree image recognition method, quantitatively evaluate the actual physical wear state indicator angle of the contacts according to the pre-processed digital image data.

[0052] S3. Calculate the remaining electrical life of the circuit breaker based on the remaining relative electrical life of the circuit breaker and the actual physical wear state indication angle of the contacts.

[0053] S4. Determine whether the remaining battery life exceeds the alarm threshold. If it does, issue an alarm signal; otherwise, return to step S1.

[0054] To further implement the above technical solution, the specific details of calculating the remaining relative electrical life of the circuit breaker include:

[0055] Step 1: Conduct a breaking test on the monitored circuit breaker, and derive the empirical formula for the electrical life of the circuit breaker, N, based on the experimental data and the contact loss law. k -I ki Lifetime curve, such as Figure 2 ;

[0056] Step 2: Obtain the breaking current value I during circuit breaker operation.ki According to N k -I ki Lifetime curve, obtain the breaking current I ki The relative number of interruptions N of the lower circuit breaker k ;

[0057] Step 3: Calculate the breaking current I based on the relative number of breaking cycles. ki The relative electrical wear Q of the contacts corresponding to a single interruption k :

[0058] Step 4: Based on the relative electrical wear Q of the contacts corresponding to a single interruption. k Given the relative electrical life L0 of the circuit breaker contacts, calculate the remaining relative electrical life L after each interruption of the circuit breaker.

[0059] To further implement the above technical solution, let the relative electrical life of a brand-new circuit breaker or a circuit breaker after major repair be 1, and let the relative contact wear Q corresponding to a single interruption be... k for:

[0060]

[0061] Where, N k The breaking current I ki The relative number of interruptions N of the lower circuit breaker k ;

[0062] The remaining relative electrical life L of the circuit breaker after each interruption is:

[0063] L=L0-∑Q k

[0064] Where L0 is the relative electrical life of the circuit breaker contacts, 0≤L0≤1.

[0065] In this embodiment, for brand-new circuit breakers or circuit breakers that have undergone major repairs, L0 is directly set to 1; for circuit breakers already in operation, the current L0 value is calculated by accumulating the electrical wear of each break based on the circuit breaker's historical breaking records and the current values ​​of each break, where L0 = 1 - ∑Q k .

[0066] To further implement the above technical solution, the specific content of the quantitative assessment of the actual physical wear state indicator angle of the contact is as follows:

[0067] Step 1: Use an industrial camera to capture images of the contact wear instrument at fixed positions at regular intervals, such as... Figure 3 And perform preprocessing, including grayscale conversion and noise reduction;

[0068] In this embodiment, a weighted average method is used to convert the image to grayscale, and a Gaussian filter is used for smoothing. Specifically:

[0069]

[0070] The Gaussian filter kernel size is x*y, the standard deviation is σ, and the parameters can be adjusted according to the filtering situation.

[0071] Step 2: Use Hough circle transform to detect the dial, and use Canny edge detection and Hough line transform to detect the pointer profile, and determine the pointer angle θ. raw ;

[0072] In this embodiment, based on the set of pixel coordinates on the pointer outline {(x1,y1),(x2,y2),…,(x... n ,y n Given that the equation of the pointer line is ax + by + c = 0, determine the pointer angle θ using the following formula. raw :

[0073]

[0074] Step 3: Convert the pointer angle to an angle in a specific coordinate system. The specific coordinate system has the center of the dial as the origin and the 0 mark as the 0-degree reference θ0.

[0075] Angle θ in a specific coordinate system con for:

[0076] θ con =(θ raw -θ0+360)%360

[0077] Among them, % is the remainder operation, ensuring that it is within the range of 0 to 360 degrees;

[0078] Step 4: Normalize the converted angle to obtain the contact wear indicator's recognition result angle θ;

[0079]

[0080] Where, θ min θ is the angle corresponding to the smallest scale mark on the dial. max This corresponds to the angle of the largest scale mark on the dial.

[0081] To further implement the above technical solution, the method for comprehensively calculating the remaining electrical life of the circuit breaker in step S3 is as follows:

[0082] L r =k l L+k θ θ

[0083] Where, k l k is the influence factor of the theoretical remaining relative electrical lifetime result L.θ The influencing factor is the result θ indicating the actual physical wear state of the contact.

[0084] Example 2

[0085] A dual-channel online monitoring system for the electrical life of a vacuum circuit breaker, based on a method for online monitoring of the electrical life of a dual-channel vacuum circuit breaker, includes: an electrical parameter acquisition module, a visible light camera, a relative electrical life calculation module, a contact wear degree instrument, an image recognition module, a comprehensive calculation module, and an alarm module;

[0086] The electrical parameter acquisition module is used to acquire the breaking current data of the main circuit of the electrical parameter channel in real time during the circuit breaker tripping operation.

[0087] A contact wear gauge is used to indicate the electrical wear condition of the contacts.

[0088] A visible light camera is used in parallel with the electrical parameter acquisition module to acquire digital image data of contact electrical wear.

[0089] The relative electrical life calculation module is used to calculate the remaining relative electrical life of the circuit breaker based on the pre-processed breaking current data using the relative electrical life method.

[0090] The image recognition module is used for image recognition methods based on the degree of electrical wear of contacts. Based on the preprocessed digital image data, it quantitatively evaluates the actual physical wear state of the contacts and indicates the angle.

[0091] The comprehensive calculation module is used to comprehensively calculate the remaining electrical life of the circuit breaker based on the remaining relative electrical life of the circuit breaker and the actual physical wear state indication angle of the contacts.

[0092] The alarm module is used to determine whether the remaining battery life exceeds the alarm threshold. If it does, an alarm signal is issued.

[0093] Example 3

[0094] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a method for online monitoring of the dual-channel electrical life of a vacuum circuit breaker.

[0095] Example 4

[0096] A processing terminal includes a memory and a processor. The memory stores a computer program that can run on the processor. When the processor executes the computer program, it implements a method for online monitoring of the dual-channel electrical life of a vacuum circuit breaker.

[0097] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0098] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for online monitoring of the electrical life of a dual-channel vacuum circuit breaker, characterized in that, Includes the following steps: S1. During the circuit breaker tripping operation, the breaking current data and contact wear condition digital image data of the main circuit of the electrical parameter channel are collected in real time and in parallel, and preprocessed. S2. Based on the relative electrical lifetime method, calculate the remaining relative electrical lifetime of the circuit breaker according to the preprocessed breaking current data; Based on the image recognition method for the degree of electrical wear of contacts, the actual physical wear state of the contacts is quantitatively evaluated and indicated by the angle based on the preprocessed digital image data. S3. Calculate the remaining electrical life of the circuit breaker based on the remaining relative electrical life of the circuit breaker and the actual physical wear state indication angle of the contacts. S4. Determine whether the remaining battery life exceeds the alarm threshold. If it does, issue an alarm signal; otherwise, return to step S1.

2. The method for online monitoring of the dual-channel electrical life of a vacuum circuit breaker according to claim 1, characterized in that, The specific details for calculating the remaining relative electrical life of a circuit breaker include: Step 1: Conduct a breaking test on the monitored circuit breaker, and derive the empirical formula for the electrical life of the circuit breaker, N, based on the experimental data and the contact loss law. k -I ki Lifetime curve; Step 2: Obtain the breaking current value I during circuit breaker operation. ki According to N k -I ki Lifetime curve, obtain the breaking current I ki The relative number of interruptions N of the lower circuit breaker k ; Step 3: Calculate the breaking current I based on the relative number of breaking cycles. ki The relative electrical wear Q of the contacts corresponding to a single interruption k : Step 4: Based on the relative electrical wear Q of the contacts corresponding to a single interruption. k Given the relative electrical life L0 of the circuit breaker contacts, calculate the remaining relative electrical life L after each interruption of the circuit breaker.

3. The method for online monitoring of the dual-channel electrical life of a vacuum circuit breaker according to claim 2, characterized in that, Assuming the relative electrical life of a brand-new circuit breaker or a circuit breaker after major repair is 1, the relative electrical wear of the contacts corresponding to a single interruption is Q. k for: Where, N k The breaking current I ki The relative number of interruptions N of the lower circuit breaker k ; The remaining relative electrical life L of the circuit breaker after each interruption is: L=L0-∑Q k Where L0 is the relative electrical life of the circuit breaker contacts, 0≤L0≤1.

4. The method for online monitoring of the dual-channel electrical life of a vacuum circuit breaker according to claim 1, characterized in that, The specific content of the indicator angle for quantitatively assessing the actual physical wear state of the contacts is as follows: Step 1: Use an industrial camera to capture images of the contact wear instrument at fixed positions at regular intervals, and perform preprocessing, including grayscale conversion and noise reduction. Step 2: Use Hough circle transform to detect the dial, and use edge detection and Hough line transform to detect the pointer profile, and determine the pointer angle θ. raw ; Step 3: Convert the pointer angle to an angle in a specific coordinate system, with the center of the dial as the origin and the 0 mark as the 0-degree reference. Step 4: Normalize the converted angle to obtain the contact wear indicator angle θ.

5. The method for online monitoring of the electrical life of a dual-channel vacuum circuit breaker according to claim 1, characterized in that, The method for comprehensively calculating the remaining electrical life of the circuit breaker in step S3 is as follows: L r =k l L+k θ i Where, k l k is the influence factor of the theoretical remaining relative electrical lifetime result L. θ The influencing factor is the result θ indicating the actual physical wear state of the contact.

6. A dual-channel online monitoring system for the electrical life of a vacuum circuit breaker, characterized in that, A method for online monitoring of the dual-channel electrical life of a vacuum circuit breaker according to any one of claims 1-5 includes: an electrical parameter acquisition module, a visible light camera, a relative electrical life calculation module, a contact wear degree instrument, an image recognition module, a comprehensive calculation module, and an alarm module; The electrical parameter acquisition module is used to acquire the breaking current data of the main circuit of the electrical parameter channel in real time during the circuit breaker tripping operation. A contact wear gauge is used to indicate the electrical wear condition of the contacts. A visible light camera is used in parallel with the electrical parameter acquisition module to acquire digital image data of contact electrical wear. The relative electrical life calculation module is used to calculate the remaining relative electrical life of the circuit breaker based on the pre-processed breaking current data using the relative electrical life method. The image recognition module is used for image recognition methods based on the degree of electrical wear of contacts. Based on the preprocessed digital image data, it quantitatively evaluates the actual physical wear state of the contacts and indicates the angle. The comprehensive calculation module is used to comprehensively calculate the remaining electrical life of the circuit breaker based on the remaining relative electrical life of the circuit breaker and the actual physical wear state indication angle of the contacts. The alarm module is used to determine whether the remaining battery life exceeds the alarm threshold. If it does, an alarm signal is issued.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the online monitoring method for the dual-channel electrical life of a vacuum circuit breaker as described in any one of claims 1-7.

8. A processing terminal, comprising a memory and a processor, wherein the memory stores a computer program executable on the processor, characterized in that, When the processor executes the computer program, it implements the online monitoring method for the dual-channel electrical life of a vacuum circuit breaker as described in any one of claims 1-7.

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