A simulation analysis method for opening distance of pole-mounted circuit breaker based on VSA

Abstract

This invention discloses a simulation analysis method for pole-mounted circuit breaker opening distance based on VSA (Variable Size Analysis). The technical solution includes: S1. Constructing a full-dimensional chain model related to the opening distance; S2. Determining the control target for the opening distance; S3. Determining the reference coordinate system for each part based on actual processing technology and assembly sequence; S4. Creating assembly relationships and measurement variables; S5. Assigning tolerance values ​​to each part based on actual process capabilities; S6. Performing Monte Carlo simulation calculations on the model with assigned tolerance values ​​to obtain the first round of simulation results; S7. Analyzing the error situation of the first round of simulation results; S8. Iterating based on the error situation until the control target is met. This invention solves the problems of complex dimensional chain calculations during design, repeated adjustments to the opening distance during assembly, and low assembly efficiency. By using VSA software for simulation analysis, the difficulty of dimensional chain calculations is reduced. Each part is processed and assembled according to the simulated tolerances and assembly sequence, eliminating the need for adjustments, thus ensuring the opening distance meets the requirements and achieving high assembly efficiency.

Description

Technical Field

[0001] This invention relates to the field of pole-mounted circuit breaker technology, and in particular to a simulation analysis method for the opening distance of pole-mounted circuit breakers based on VSA. Background Technology

[0002] The opening distance of a pole-mounted circuit breaker, which is the distance between the moving and stationary contacts when they separate, is one of the key parameters affecting product performance and safety. The size of the opening distance directly affects the arc-extinguishing capability, insulation strength, and operational reliability of the pole-mounted circuit breaker. The following are the main impacts of the opening distance on pole-mounted circuit breakers:

[0003] 1. Insufficient opening distance:

[0004] A. Decreased arc extinguishing ability may result in the arc not being able to be sufficiently elongated and cooled, making it difficult to effectively extinguish the arc. When interrupting large currents, it is easy to cause the arc to reignite or continue to burn, damaging the contacts or insulation.

[0005] B. May cause insulation breakdown between contacts, leading to phase-to-phase short circuits or discharge to ground.

[0006] 2. Excessive opening distance:

[0007] A. Higher energy is required for the trip spring, which may lead to mechanism failure, such as spring fatigue or connecting rod deformation;

[0008] B. With frequent operation, an excessively large opening distance may accelerate contact collisions or mechanical wear, shortening product life.

[0009] The opening distance of pole-mounted circuit breakers needs to strike a balance between arc-extinguishing performance, insulation strength, and mechanical reliability. Its design requires comprehensive consideration of voltage level, arc-extinguishing medium, operating mechanism capability, and environmental conditions. The opening distance must comply with national standards or power grid company technical specifications, and is typically calculated and determined based on parameters such as rated voltage and short-circuit current. For example, the opening distance of a 10kV vacuum circuit breaker is typically 8–10mm; the opening distance of a 35kV SF6 circuit breaker may reach 50–100mm. This invention uses 10kV as an example, and after comprehensively considering its arc-extinguishing performance, insulation strength, and mechanical reliability, the optimal opening distance range is 9±0.5mm.

[0010] In the design of pole-mounted circuit breakers, traditional design methods require manual dimensional chain calculations to ensure that the opening distance meets requirements after assembly. This is difficult because it's hard to determine the relationship between cumulative errors and tolerances of individual parts, making it impossible to accurately pinpoint how to control and optimize component tolerances. The dimensional chain calculations are extensive and complex. In actual production, due to the numerous parts and complex connections, the measured opening distance range after assembly may exceed 9±0.5mm. This necessitates adjustment for each unit, which is extremely cumbersome due to limited space, numerous parts, and complex connections. Even with specialized tooling, the efficiency of opening distance adjustment cannot be improved, resulting in low overall efficiency. Currently, there are no other efficient methods in the industry. Summary of the Invention

[0011] This invention addresses the shortcomings and defects of existing technologies by providing a simulation analysis method for pole-mounted circuit breaker opening distance based on VSA. This method reduces the difficulty of dimensional chain calculation. After each part is processed and assembled according to the final assigned tolerance value, the opening distance can meet the requirements without adjustment, resulting in high assembly efficiency.

[0012] The objective of this invention can be achieved through the following technical solutions:

[0013] A simulation analysis method for pole-mounted circuit breaker opening distance based on VSA includes the following steps:

[0014] S1. Construct a full-size chain model related to the open distance;

[0015] S2. Determine the control target for the opening distance;

[0016] S3. Based on the actual processing technology and assembly sequence, determine the reference coordinate system of each part;

[0017] S4. Create assembly relationships and measurement variables;

[0018] S5. Assign tolerance values ​​to each part based on actual process capabilities;

[0019] S6. Perform Monte Carlo simulation calculations on the model with tolerance values ​​to obtain the first round of simulation results;

[0020] S7. Analyze the error situation of the first round of simulation results;

[0021] S8. Iterate based on the error situation until the control objective is met.

[0022] Furthermore, in the simulation analysis method for pole-mounted circuit breaker opening distance based on VSA, the model construction process of S1 is as follows:

[0023] S11. Determine the models of all components related to the opening distance;

[0024] S12. Simplify the component models in 3D software according to the assembly rules of VSA;

[0025] S13. Import the simplified model into VSA software;

[0026] S14. In VSA, based on the actual processing technology and assembly process route, divide the imported model into assembly components.

[0027] Furthermore, in the simulation analysis method for pole-mounted circuit breaker opening distance based on VSA, the process of constructing the reference coordinate system of S3 is as follows:

[0028] S31. Based on the actual processing technology and assembly sequence of each part, determine the first datum, second datum, third datum and local datum of each part, and then determine the datum coordinate system of each part.

[0029] Furthermore, in the simulation analysis method for pole-mounted circuit breaker opening distance based on VSA, the construction process of S4 is as follows:

[0030] S41. Based on the assembly characteristics and sequence of components, define the assembly operations of each component in VSA;

[0031] S42. In VSA, the opening distance is used as a measurement variable.

[0032] Furthermore, in the simulation analysis method for pole-mounted circuit breaker opening distance based on VSA, the first round of simulation results in S6 includes the numerical range of the measured variables, contribution factors, and influence degree, wherein the contribution factors are sorted from high to low according to the influence degree.

[0033] Furthermore, in the simulation analysis method for pole-mounted circuit breaker opening distance based on VSA, the analysis process of S7 is as follows:

[0034] S71. Based on the numerical range of the measured variables, compare them with the control target of the opening distance;

[0035] S72. Analyze the direction of change of each contributing factor in descending order of influence.

[0036] Furthermore, in the simulation analysis method for pole-mounted circuit breaker opening distance based on VSA, the iteration process of S8 is as follows: based on the contribution factor and influence degree, if the numerical range of the measured variable exceeds the control target of the opening distance, the assembly sequence is optimized, or the tolerance requirements are adjusted based on the existing process capability, until the numerical range of the measured variable is within the control target of the opening distance.

[0037] The beneficial technical effects of this invention are: it reduces the difficulty of dimensional chain calculation; after each part is processed and assembled according to the final assigned tolerance value, no adjustment is required to ensure that the opening distance meets the requirements, resulting in high assembly efficiency. Attached Figure Description

[0038] Figure 1 This is a flowchart of the present invention.

[0039] Figure 2 It is a model diagram of all components related to the opening distance.

[0040] Figure (a) is a diagram of the overall components;

[0041] Figure (b) is a component diagram of the internal parts after concealing the external components such as the main board, liner, and base plate of the enclosure;

[0042] Figure (c) is a diagram of the components of the pole section;

[0043] Figure (d) is the AA sectional view of Figure (c).

[0044] Figure 3 This is a dimensional tolerance chart for the parts with the top 12 contribution factors.

[0045] Figure (a) is a drawing of the bracket parts;

[0046] Figure (b) is a diagram of the pole piece;

[0047] Figure (c) is a drawing of the liner base plate part;

[0048] Figure (d) is a diagram of the mainboard components for the chassis;

[0049] Figure (e) is a drawing of the connecting rod part;

[0050] Figure (f) is a drawing of the main output shaft parts.

[0051] Figure 4 This is a diagram showing the results of the first round of simulation.

[0052] Figure 5 This is a graph showing the top 12 contribution factors and their impact from the first round of simulation results.

[0053] Figure 6 This is a simulation result diagram after iterative analysis.

[0054] Figure 7 This is a graph showing the top 12 contributing factors and their influence in the simulation results after iterative analysis.

[0055] Reference numerals: 1. Main body of the housing; 2. Liner base plate; 3. Drive rod; 4. Left bracket; 5. Output connection plate main body; 6. Output shaft spindle; 7. Bracket; 8. Right connection plate; 9. Right bracket; 10. Left connection plate; 11. Output shaft bushing; 12. Connecting rod; 13. Stop washer; 14. Drive rod connecting pin; 15. Pole post; 16. Drive rod roller pin; 17. Output shaft limit roller; 18. Output shaft limit roller pin; 19. [Unclear text - possibly a component name or part number] 20. Brake drive shaft limit sleeve, 21. UCBF-1006 sleeve, 22. Opening limit claw pin, 23. Opening limit claw, 24. Drive rod connecting roller, 25. Assembly pad, 26. Bracket support shaft, 27. Bearing, 28. Opening half shaft, 29. Opening limit plate, 30. Opening drive shaft, 31. Opening drive shaft support sleeve, 32. Output shaft copper sleeve, 33. Adjusting head, 34. Pole column connecting rod, 35. Moving contact, 36. Stationary contact. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and do not limit the scope of the invention.

[0057] Example 1: A simulation analysis method for pole-mounted circuit breaker opening distance based on VSA. The flowchart of this invention is shown below. Figure 1 The following is a detailed explanation:

[0058] S1. Construct a full-size chain model related to the opening distance. This step includes:

[0059] S11. Based on the dimension chain, determine all component models related to the opening distance, where the distance between the moving contact 34 and the stationary contact 35 is the opening distance;

[0060] In S12.VSA, the assembly of parts and components is mostly in the form of surface mating, shaft-hole mating, keyway mating, point-to-point mating, etc., and the 3D model needs to be simplified into a model that facilitates the above assembly.

[0061] S13. Import the simplified model into VSA software;

[0062] S14. In VSA, based on the actual processing technology and assembly process route, the imported model is divided into assembly components. This makes the model creation order clearer and increases the readability of the digital model.

[0063] S2. Determine the control target for the opening distance, which is 9±0.5mm.

[0064] S3. Based on the actual machining process and assembly sequence, determine the reference coordinate system for each part. This step includes:

[0065] S31. Based on the actual machining process and assembly sequence of each part, determine the first datum, second datum, third datum, and local datum of each part, and then determine the datum coordinate system of each part. Some parts have three main datums and some local datums, while some parts have only one datum, and some parts have no datums. See the example of the datum status of specific parts. Figure 3 It only shows the component diagrams of the top 12 contributing factors in terms of influence.

[0066] S4. Create assembly relationships and measurement variables. This step includes:

[0067] S41. Based on the assembly characteristics and sequence of components, define the assembly operations of each component in VSA and assemble each component.

[0068] S42. In VSA, the opening distance is used as a measurement variable.

[0069] S5. Assign tolerance values ​​to each part based on actual manufacturing capabilities. See examples of specific part tolerance values. Figure 3 It only shows the component diagrams of the top 12 contributing factors in terms of influence.

[0070] S6. For the model with tolerance values, perform Monte Carlo simulation calculations to obtain the first round of simulation results, including the numerical range of the measured variables, contribution factors, and influence, as shown below. Figure 4 , Figure 5 The contribution factors are sorted from highest to lowest according to their influence, and only the top 12 contribution factors in terms of influence are shown.

[0071] S7. Analyze the error situation of the first round of simulation results;

[0072] S71. Based on the numerical range of the measured variables, compare it with the control target of the opening distance, and then... Figure 4 It can be seen that the opening distance range is 8.2192 to 9.7815, which exceeds the control target of 9±0.5.

[0073] S72. Analyze the direction of change of each contributing factor in descending order of influence. Figure 5 As can be seen, the contributing factors are ranked from highest to lowest influence and analyzed one by one. The figure shows that the lower-ranked influencing factors actually have minimal impact on the opening distance, with influence levels all below 1%. Therefore, only the top 12 influencing factors are shown, and the same applies below. Analysis revealed that among the contributing factors affecting the opening distance, the positional accuracy of the pole-center hole has the greatest impact and needs to be reduced to 0.1.

[0074] S8. Perform iterative analysis to obtain a new round of results, including the numerical range of the measured variables, contribution factors, and influence, as detailed below. Figure 6 , Figure 7 ,Depend on Figure 6 It can be seen that the opening distance range is 8.5086~9.4919, which meets the control target of 9±0.5. The influence of the positional accuracy of the pole post-center hole on the opening distance has dropped to second place, and other contribution factors are also reasonably distributed. Figure 6 It is known that using 5 sigma for Monte Carlo simulation results in a defect rate of less than one in a million, meaning that almost no defective products are produced. This is because the opening distance of each pole-mounted circuit breaker is tested before leaving the factory. If the opening distance fails the test before leaving the factory, it can be adjusted. However, the number of products requiring adjustment is less than one in a million, which is extremely small. It is almost possible to achieve the goal of not needing to adjust the opening distance, as it will be within the target range.

[0075] The above embodiments are descriptions of specific implementations of the present invention. Although the accompanying drawings in the specification only show part diagrams of the top 12 contribution factors in terms of influence, this is not a limitation of the present invention. Those skilled in the art can make various transformations and changes without departing from the spirit and scope of the present invention to obtain corresponding equivalent technical solutions. Therefore, all equivalent technical solutions should be included in the patent protection scope of the present invention.

Claims

1. A simulation analysis method for pole-mounted circuit breaker opening distance based on VSA, characterized in that, Includes the following steps: S1. Construct a full-size chain model related to the open distance; S2. Determine the control target for the opening distance; S3. Based on the actual processing technology and assembly sequence, determine the reference coordinate system of each part; S4. Create assembly relationships and measurement variables; S5. Assign tolerance values ​​to each part based on actual process capabilities; S6. Perform Monte Carlo simulation calculations on the model with tolerance values ​​to obtain the first round of simulation results; S7. Analyze the error situation of the first round of simulation results; S8. Iterate based on the error situation until the control objective is met.

2. The simulation analysis method for pole-mounted circuit breaker opening distance based on VSA according to claim 1, characterized in that, The model construction process for S1 is as follows: S11. Determine the models of all components related to the opening distance; S12. Simplify the component models in 3D software according to the assembly rules of VSA; S13. Import the simplified model into VSA software; S14. In VSA, based on the actual processing technology and assembly process route, divide the imported model into assembly components.

3. The simulation analysis method for pole-mounted circuit breaker opening distance based on VSA according to claim 1, characterized in that, The process of constructing the reference coordinate system of S3 is as follows: S31. Based on the actual processing technology and assembly sequence of each part, determine the first datum, second datum, third datum and local datum of each part, and then determine the datum coordinate system of each part.

4. The simulation analysis method for pole-mounted circuit breaker opening distance based on VSA according to claim 1, characterized in that, The construction process of S4 is as follows: S41. Based on the assembly characteristics and sequence of components, define the assembly operations of each component in VSA; S42. In VSA, the opening distance is used as a measurement variable.

5. The simulation analysis method for pole-mounted circuit breaker opening distance based on VSA according to claim 1, characterized in that, In S6, the first round of simulation results includes the numerical range of the measured variables, contribution factors, and influence, wherein the contribution factors are sorted from high to low according to the influence.

6. The simulation analysis method for pole-mounted circuit breaker opening distance based on VSA according to claim 1, characterized in that, The analysis process of S7 is as follows: S71. Based on the numerical range of the measured variables, compare them with the control target of the opening distance; S72. Analyze the direction of change of each contributing factor in descending order of influence.

7. The simulation analysis method for pole-mounted circuit breaker opening distance based on VSA according to claim 1, characterized in that, The iterative process of S8 is as follows: Based on the contribution factor and influence degree, if the numerical range of the measured variable exceeds the control target of the opening distance, the assembly sequence is optimized, or the tolerance requirements are adjusted based on the existing process capability, until the numerical range of the measured variable is within the control target of the opening distance.

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