High-voltage circuit breaker spring defect detection method based on magnetic induction technology

Abstract

The invention relates to the technical field of spring defect identification, in particular to a high-voltage circuit breaker spring defect detection method based on a magnetic induction technology, and the method comprises the steps: building a spring model matched with a high-voltage circuit breaker spring; applying a load with the same value as the field on the plane of the spring in the spring model to obtain the stress field distribution of the spring of the high-voltage circuit breaker; vON MISES stress expression is adopted to judge whether the high-voltage circuit breaker spring has plastic yield fatigue failure or not. And the defect detection mode is simple and convenient, the on-site load value can be obtained only by adopting the existing common technology, and the method is suitable for large-scale popularization. Besides, after the stress values of the multiple stress points of the spring are collected and the acoustic signal characteristic distribution diagram is obtained, the stress field distribution of the spring of the high-voltage circuit breaker can be obtained based on a mathematical fitting algorithm, so that the precision is higher and the accuracy is higher.

Description

Technical Field

[0001] The invention relates to the technical field of spring defect identification, and in particular to a high-voltage circuit breaker spring defect detection method based on magnetic induction technology. Background Art

[0002] Circuit breakers have been widely promoted and used in power systems. In the spring operating mechanism of the circuit breaker, the quality of the energy storage spring is directly related to the normal operation of the spring operating mechanism. Therefore, the energy storage spring plays a very important role in the operating performance of the entire circuit breaker and even the entire power grid. At present, the energy storage spring may be damaged for two reasons. On the one hand, there are dents on the surface of the energy storage spring when it leaves the factory. Accidental damage such as bumps and scratches during transportation and installation have a serious impact on the performance and life of the spring; on the other hand, during long-term operation, the energy storage spring will experience fatigue crack expansion, creep crack expansion, and even spring wire breakage, which will cause mechanical failure of the spring operating mechanism of the circuit breaker during operation, which poses a certain potential threat to the safe operation of the power grid.

[0003] Therefore, there is an urgent need to provide a high-voltage circuit breaker spring defect detection method based on magnetic induction technology to solve the above problems. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a high-voltage circuit breaker spring defect detection method based on magnetic induction technology.

[0005] To solve the above problems, the technical solution adopted by the present invention is:

[0006] On the one hand, a method for detecting spring defects of a high-voltage circuit breaker based on magnetic induction technology is provided, the method comprising:

[0007] Step 1: Establish a spring model that matches the high-voltage circuit breaker spring;

[0008] Step 2: applying a load of the same value as that on site to the plane of the spring in the spring model to obtain the stress field distribution of the high-voltage circuit breaker spring;

[0009] Step 3: Use VON MISES stress expression to determine whether plastic yield fatigue failure occurs in the high-voltage circuit breaker spring.

[0010] As an implementation mode of the invention, in the step 2, the method of obtaining the stress field distribution of the high-voltage circuit breaker spring includes:

[0011] Step S201, collecting stress values ​​at multiple stress points of the spring through an acoustic wave sensor to obtain an acoustic signal characteristic distribution diagram;

[0012] Step S202: using a mathematical fitting algorithm to obtain the stress field distribution of the high-voltage circuit breaker spring according to a plurality of stress values.

[0013] As an implementation mode of the invention, in step S201, a magnetic sound source conversion layer is provided on the acoustic wave sensor, and the conversion and focusing of the sound source are achieved by combining metal magnetic material plating with sound penetration.

[0014] As an implementation mode of the invention, step S202 includes:

[0015] The relative value of the resultant force at the force point is calculated based on the following formula:

[0016]

[0017] Among them, E t Represents the relative value of the resultant force at the t-th force point, S t It represents the area enclosed by the fitting curve and the coordinate axis in the characteristic distribution diagram of the acoustic signal at the t-th force point;

[0018] The actual stress value of each stress point is calculated using the following formula:

[0019]

[0020] Among them, σ i1 It represents the actual stress value of the i-th stress point, and the actual stress value of each stress point is used as the actual stress lateral distribution coefficient of each stress point to obtain the stress field distribution.

[0021] As an implementation mode of the invention, in step 3, the VON MISES stress expression is as follows:

[0022]

[0023] Among them, σ1, σ2, and σ3 are the three principal stresses at the maximum stress point.

[0024] On the other hand, a high-voltage circuit breaker spring defect detection device based on magnetic induction technology is provided, the device comprising:

[0025] A model building module, which is used to build a spring model matching the high-voltage circuit breaker spring;

[0026] A stress field acquisition module is used to apply a load of the same value as that on site to the plane of the spring in the spring model to obtain the stress field distribution of the high-voltage circuit breaker spring;

[0027] The judgment module is used to use VON MISES stress expression to judge whether the high-voltage circuit breaker spring has plastic yield fatigue failure.

[0028] As an embodiment of the invention, the stress field acquisition module includes:

[0029] A characteristic distribution diagram generating unit, which is used to collect stress values ​​at multiple stress points of the spring through an acoustic wave sensor to obtain an acoustic signal characteristic distribution diagram;

[0030] The stress field acquisition unit is used to obtain the stress field distribution of the high-voltage circuit breaker spring according to a plurality of stress values ​​by using a mathematical fitting algorithm.

[0031] As an embodiment of the invention, a magnetic sound source conversion layer is provided on the acoustic wave sensor, and the conversion and focusing of the sound source are achieved by combining metal magnetic material plating with sound penetration.

[0032] As an embodiment of the invention, the stress field acquisition unit is also used for:

[0033] The relative value of the resultant force at the force point is calculated based on the following formula:

[0034]

[0035] Among them, E t Represents the relative value of the resultant force at the t-th force point, S t It represents the area enclosed by the fitting curve and the coordinate axis in the characteristic distribution diagram of the acoustic signal at the t-th force point;

[0036] The actual stress value of each stress point is calculated using the following formula:

[0037]

[0038] Among them, δ i1 It represents the actual stress value of the i-th stress point, and the actual stress value of each stress point is used as the actual stress lateral distribution coefficient of each stress point to obtain the stress field distribution.

[0039] As an embodiment of the invention, the VON MISES stress expression is as follows:

[0040]

[0041] Among them, σ1, σ2, and σ3 are the three largest actual stress values.

[0042] The beneficial effects of adopting the above technical solution are:

[0043] The high-voltage circuit breaker spring defect detection method based on magnetic induction technology provided by the present invention establishes a spring model matching the high-voltage circuit breaker spring; applies a load of the same value as that on site to the plane of the spring in the spring model to obtain the stress field distribution of the high-voltage circuit breaker spring; and uses VON MISES stress expression to determine whether the high-voltage circuit breaker spring has plastic yield fatigue failure. Its defect detection method is simple and only requires the use of existing commonly used technologies to obtain the load value on site, which is suitable for large-scale promotion.

[0044] In addition, after collecting the stress values ​​at multiple stress points of the spring and obtaining the characteristic distribution diagram of the acoustic signal, the stress field distribution of the high-voltage circuit breaker spring is obtained based on a mathematical fitting algorithm, which has higher precision and accuracy. DETAILED DESCRIPTION

[0045] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is clearly and completely described below in conjunction with specific embodiments.

[0046] Example 1

[0047] An embodiment of the present invention provides a high-voltage circuit breaker spring defect detection method based on magnetic induction technology, the method comprising:

[0048] Step 1: Establish a spring model that matches the high-voltage circuit breaker spring;

[0049] Step 2: applying a load of the same value as that on site to the plane of the spring in the spring model to obtain the stress field distribution of the high-voltage circuit breaker spring;

[0050] When the spring in the circuit breaker is analyzed by the finite element method, there is no simplification of the model. The load can be directly added to the planes at both ends of the spring. According to the actual situation, the displacement load is applied during the analysis, which is consistent with the actual working conditions of the spring, thereby ensuring the accuracy of the stress field boundary conditions. For the interior of the structure, the stress field distribution is solely determined by the boundary conditions. Therefore, according to the accurate boundary conditions, as long as the model is accurate and the mesh refinement reaches a certain level, the accurate stress field distribution can be obtained.

[0051] It includes:

[0052] Step S201, collecting stress values ​​at multiple stress points of the spring through an acoustic wave sensor to obtain a characteristic distribution diagram of the acoustic signal; in this step, a magnetic sound source conversion layer is provided on the acoustic wave sensor, and the conversion and focusing of the sound source are achieved by combining metal magnetic material plating with sound penetration.

[0053] Step S202: using a mathematical fitting algorithm to obtain the stress field distribution of the high-voltage circuit breaker spring according to a plurality of stress values.

[0054] This step includes:

[0055] The relative value of the resultant force at the force point is calculated based on the following formula:

[0056]

[0057] Among them, E t Represents the relative value of the resultant force at the t-th force point, S t It represents the area enclosed by the fitting curve and the coordinate axis in the characteristic distribution diagram of the acoustic signal at the t-th force point;

[0058] The actual stress value of each stress point is calculated using the following formula:

[0059]

[0060] Among them, σ i1 It represents the actual stress value of the i-th stress point, and the actual stress value of each stress point is used as the actual stress lateral distribution coefficient of each stress point to obtain the stress field distribution.

[0061] Step 3: Use VON MISES stress expression to determine whether plastic yield fatigue failure occurs in the high-voltage circuit breaker spring.

[0062] The VON MISES stress expression is as follows:

[0063]

[0064] Among them, σ1, σ2, and σ3 are the three principal stresses at the maximum stress point.

[0065] During the compression deformation process, the loads borne by the spring cross section include shear stress, torque, torque, and compressive stress. In addition, the spring has a certain curvature, so its actual deformation is complicated. Usually, when calculating, it is assumed that the cross section remains flat, and the influence of shear stress and compressive stress with smaller influence is ignored. For the case where the pressure acts on the spring axis, it can also be concluded that the torque is zero. In this way, only the influence of torque can be considered on the cross section, so the accuracy of this application is high.

[0066] The high-voltage circuit breaker spring defect detection method based on magnetic induction technology provided by the present invention establishes a spring model matching the high-voltage circuit breaker spring; applies a load of the same value as that on site to the plane of the spring in the spring model to obtain the stress field distribution of the high-voltage circuit breaker spring; and uses VON MISES stress expression to determine whether the high-voltage circuit breaker spring has plastic yield fatigue failure. Its defect detection method is simple and only requires the use of existing commonly used technologies to obtain the load value on site, which is suitable for large-scale promotion.

[0067] In addition, after collecting the stress values ​​at multiple stress points of the spring and obtaining the characteristic distribution diagram of the acoustic signal, the stress field distribution of the high-voltage circuit breaker spring is obtained based on a mathematical fitting algorithm, which has higher precision and better accuracy.

[0068] Example 2

[0069] An embodiment of the present invention provides a high-voltage circuit breaker spring defect detection device based on magnetic induction technology, the device comprising:

[0070] A model building module, which is used to build a spring model matching the high-voltage circuit breaker spring;

[0071] A stress field acquisition module is used to apply a load of the same value as that on site to the plane of the spring in the spring model to obtain the stress field distribution of the high-voltage circuit breaker spring;

[0072] The judgment module is used to use VON MISES stress expression to judge whether the high-voltage circuit breaker spring has plastic yield fatigue failure.

[0073] Furthermore, the stress field acquisition module includes:

[0074] A characteristic distribution diagram generating unit, which is used to collect stress values ​​at multiple stress points of the spring through an acoustic wave sensor to obtain an acoustic signal characteristic distribution diagram;

[0075] The stress field acquisition unit is used to obtain the stress field distribution of the high-voltage circuit breaker spring according to a plurality of stress values ​​by using a mathematical fitting algorithm.

[0076] Furthermore, a magnetic sound source conversion layer is provided on the acoustic wave sensor, and the conversion and focusing of the sound source are achieved by combining metal magnetic material plating with sound penetration.

[0077] Furthermore, the stress field acquisition unit is also used for:

[0078] The relative value of the resultant force at the force point is calculated based on the following formula:

[0079]

[0080] Among them, E t Represents the relative value of the resultant force at the t-th force point, S t It represents the area enclosed by the fitting curve and the coordinate axis in the characteristic distribution diagram of the acoustic signal at the t-th force point;

[0081] The actual stress value of each stress point is calculated using the following formula:

[0082]

[0083] Among them, δ i1It represents the actual stress value of the i-th stress point, and the actual stress value of each stress point is used as the actual stress lateral distribution coefficient of each stress point to obtain the stress field distribution.

[0084] Furthermore, the VON MISES stress expression is as follows:

[0085]

[0086] Among them, σ1, σ2, and σ3 are the three largest actual stress values.

[0087] The high-voltage circuit breaker spring defect detection device based on magnetic induction technology provided by the present invention establishes a spring model matching the high-voltage circuit breaker spring; applies a load of the same value as that on site to the plane of the spring in the spring model to obtain the stress field distribution of the high-voltage circuit breaker spring; and uses VON MISES stress expression to determine whether the high-voltage circuit breaker spring has plastic yield fatigue failure. Its defect detection method is simple, and only the existing commonly used technology needs to be used to obtain the load value on site, which is suitable for large-scale promotion.

[0088] In addition, after collecting the stress values ​​at multiple stress points of the spring and obtaining the characteristic distribution diagram of the acoustic signal, the stress field distribution of the high-voltage circuit breaker spring is obtained based on a mathematical fitting algorithm, which has higher precision and accuracy.

Claims

1. A high-voltage circuit breaker spring defect detection method based on magnetic induction technology, characterized in that: The method comprises: Step 1: Establish a spring model that matches the high-voltage circuit breaker spring; Step 2: applying a load of the same value as that on site to the plane of the spring in the spring model to obtain the stress field distribution of the high-voltage circuit breaker spring; Step 3: Use VON MISES stress expression to determine whether plastic yield fatigue failure occurs in the high-voltage circuit breaker spring.

2. A high-voltage circuit breaker spring defect detection method based on magnetic induction technology according to claim 1, characterized in that: In the step 2, the method of obtaining the stress field distribution of the high-voltage circuit breaker spring includes: Step S201, collecting stress values ​​at multiple stress points of the spring through an acoustic wave sensor to obtain an acoustic signal characteristic distribution diagram; Step S202: using a mathematical fitting algorithm to obtain the stress field distribution of the high-voltage circuit breaker spring according to a plurality of stress values.

3. The method for detecting spring defects of a high-voltage circuit breaker based on magnetic induction technology according to claim 2 is characterized in that: In step S201, a magnetic sound source conversion layer is provided on the acoustic wave sensor, and the conversion and focusing of the sound source are achieved by combining metal magnetic material plating with sound penetration.

4. The method for detecting spring defects of a high-voltage circuit breaker based on magnetic induction technology according to claim 2 is characterized in that: Step S202 includes: The relative value of the resultant force at the force point is calculated based on the following formula: Among them, E t represents the relative value of the resultant force at the t-th force point, S t It represents the area enclosed by the fitting curve and the coordinate axis in the characteristic distribution diagram of the acoustic signal at the t-th force point; The actual stress value of each stress point is calculated using the following formula: Among them, σ i1 It represents the actual stress value of the i-th stress point, and the actual stress value of each stress point is used as the actual stress lateral distribution coefficient of each stress point to obtain the stress field distribution.

5. The method for detecting spring defects of a high-voltage circuit breaker based on magnetic induction technology according to claim 1 is characterized in that: In step 3, the VON MISES stress expression is as follows: Among them, σ1, σ2, and σ3 are the three principal stresses at the maximum stress point.

6. A high-voltage circuit breaker spring defect detection device based on magnetic induction technology, characterized in that: The device comprises: A model building module, which is used to build a spring model matching the high-voltage circuit breaker spring; A stress field acquisition module is used to apply a load of the same value as that on site to the plane of the spring in the spring model to obtain the stress field distribution of the high-voltage circuit breaker spring; The judgment module is used to use VON MISES stress expression to judge whether the high-voltage circuit breaker spring has plastic yield fatigue failure.

7. The high-voltage circuit breaker spring defect detection device based on magnetic induction technology according to claim 1 is characterized in that: The stress field acquisition module comprises: A characteristic distribution diagram generating unit, which is used to collect stress values ​​at multiple stress points of the spring through an acoustic wave sensor to obtain an acoustic signal characteristic distribution diagram; The stress field acquisition unit is used to obtain the stress field distribution of the high-voltage circuit breaker spring according to a plurality of stress values ​​by using a mathematical fitting algorithm.

8. A high voltage circuit breaker spring defect detection device based on magnetic induction technology according to claim 7, characterized in that: The acoustic wave sensor is provided with a magnetic sound source conversion layer, which realizes the conversion and focusing of the sound source by combining the metal magnetic material coating method with the sound penetration.

9. A high voltage circuit breaker spring defect detection device based on magnetic induction technology according to claim 7, characterized in that: The stress field acquisition unit is also used for: The relative value of the resultant force at the force point is calculated based on the following formula: Among them, E t represents the relative value of the resultant force at the t-th force point, S t It represents the area enclosed by the fitting curve and the coordinate axis in the characteristic distribution diagram of the acoustic signal at the t-th force point; The actual stress value of each stress point is calculated using the following formula: Among them, δ i1 It represents the actual stress value of the i-th stress point, and the actual stress value of each stress point is used as the actual stress lateral distribution coefficient of each stress point to obtain the stress field distribution.

10. The high-voltage circuit breaker spring defect detection device based on magnetic induction technology according to claim 6, characterized in that: The VON MISES stress expression is as follows: Among them, σ1, σ2, and σ3 are the three largest actual stress values.

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