Circuit breaker stroke high-precision calculation method based on multi-connecting-rod kinematics analysis

Abstract

The invention discloses a circuit breaker stroke high-precision calculation method based on multi-connecting-rod kinematics analysis. The circuit breaker stroke high-precision calculation method comprises the steps that a non-intrusive mechanical characteristic sensor arranged in a main shaft of a vacuum circuit breaker is used for collecting the initial rotation angle of the main shaft of the circuit breaker in real time; establishing a multi-link motion model of the circuit breaker transmission mechanism; inputting the collected main shaft initial rotation angle of the circuit breaker into the multi-connecting-rod motion model, and calculating a first moving point coordinate; establishing and solving a quadratic equation based on a double-circle intersection point principle, and obtaining coordinates of a second moving point; and calculating the stroke of the contact through vector rotation according to the coordinates of the second moving point and the coordinates of the fixed point. A complex multi-connecting-rod kinematics problem is innovatively converted into a quadratic equation rooting problem, so that the calculation efficiency and precision are greatly improved, and nondestructive acquisition and high-precision analysis of mechanical characteristics of the circuit breaker are realized.

Description

Technical Field

[0001] This invention relates to the field of condition monitoring technology for high-voltage electrical equipment, specifically to a high-precision calculation method for circuit breaker stroke based on multi-link kinematic analysis. Background Technology

[0002] Promoting the deep integration of digital technology with power transmission and distribution equipment to empower the digital and intelligent transformation and upgrading of the power grid is a crucial part of accelerating the planning and construction of a new energy system. Currently, my country's traditional power system is evolving into a new type of power system that is clean and low-carbon, safe and controllable, flexible and efficient, open and interactive, and smart and user-friendly. Intelligent circuit breakers, with their advantages in status sensing and performance evaluation, have been increasingly accepted and valued by enterprises.

[0003] However, existing technologies suffer from high computational complexity and poor real-time performance when analyzing the mechanical characteristic parameters of circuit breakers. For example, the traditional triangular iteration method used in patent CN116625667A requires 13 calculation steps and takes more than 50ms on the STM32F407 platform, which cannot meet the high-frequency response requirements of real-time monitoring and control of circuit breakers. The polynomial fitting method used in patent CN113155421A requires the pre-storage of hundreds of feature points, consuming a large amount of storage resources, which is not conducive to equipment miniaturization and cost control. Traditional geometric methods are prone to cumulative errors in multiple transmission conversions, resulting in large deviations in overtravel calculations and failing to accurately reflect the actual displacement of the contacts, which seriously affects the ability to identify faults such as early fatigue of springs and jamming of mechanisms.

[0004] Therefore, there is an urgent need for a high-precision, low-computational-complexity method for calculating circuit breaker travel to support the reliable application of smart circuit breakers in practical engineering. Summary of the Invention

[0005] In order to solve the above-mentioned technical problems, this application proposes the following technical solution: This application provides a high-precision calculation method for circuit breaker stroke based on multi-link kinematic analysis, including: The initial rotation angle of the circuit breaker's main shaft is collected in real time by a non-invasive mechanical characteristic sensor installed inside the main shaft of the vacuum circuit breaker. Establish a multi-link motion model of the circuit breaker transmission mechanism; The initial rotation angle of the main shaft of the circuit breaker is collected and input into the multi-link motion model to calculate the coordinates of the first moving point; Based on the principle of the intersection of two circles, a quadratic equation is established and solved to obtain the coordinates of the second moving point; The contact stroke is calculated by combining the coordinates of the second moving point with the coordinates of the fixed point through vector rotation.

[0006] In one possible implementation, establishing the multi-link motion model of the circuit breaker transmission mechanism includes: Define the main shaft of the circuit breaker as the origin; The hinge point between the first link and the second link is the first moving point; the hinge point between the second link and the third link is the second moving point; the hinge point between the third link and the fourth link is the fixed point; and the hinge point between the fourth link and the pole rod is the third moving point. The distance between the origin and the first moving point is the first distance, the distance between the first moving point and the second moving point is the second distance, the distance between the second moving point and the fixed point is the third distance, the distance between the fixed point and the third moving point is the fourth distance, and the horizontal component of the distance between the fixed point and the origin is X, and the vertical component is Y. When switching between opening and closing, the trajectory diagrams of the first moving point, the second moving point, and the third moving point are drawn.

[0007] In one possible implementation, the formula for calculating the coordinates of the first moving point is: in, The distance between the origin and the first moving point. This is the initial rotation angle of the circuit breaker's spindle.

[0008] In one possible implementation, the step of establishing and solving the quadratic equation based on the principle of intersection of two circles to obtain the coordinates of the second moving point includes: Obtain the initial rotation angle of the circuit breaker's main shaft, the coordinates of the first moving point, the coordinates of the fixed point, the length of the second link, and the length of the third link; Based on the initial rotation angle of the circuit breaker's main shaft, the coordinates of the first moving point, the coordinates of the fixed point, the length of the second link, and the length of the third link, an equation is established, and the calculation formula is as follows: in, Let these be the coordinates of the second moving point. Let these be the coordinates of the first moving point. For fixed point coordinates, The length of the second link. The length of the third link. The distance between the origin and the first moving point. This is the initial rotation angle of the circuit breaker's spindle; The equation is simplified to obtain a quadratic equation about the x-coordinate of the second moving point. The calculation formula is as follows: in, The coordinates of the second moving point are obtained by solving the quadratic equation using the following formula: .

[0009] In one possible implementation, the contact stroke is calculated by vector rotation based on the coordinates of the second moving point and the coordinates of the fixed point, including: Obtain the coordinates of the fixed point and the angle between the third and fourth links; The vector between the second moving point and the fixed point is calculated using the following formula: Using vector rotation, the angle between the third and fourth links is scaled to the distance between the fixed point and the third moving point. The calculation formula is as follows: Where c is the angle between the third and fourth links. Let these be the coordinates of the second moving point. For fixed point coordinates, The length of the third link. The distance between the fixed point and the third moving point; The coordinates of the third moving point are calculated based on the vector between the fixed point and the third moving point; Extract the y-coordinate of the third moving point and use the y-coordinate of the third moving point as the contact stroke of the circuit breaker.

[0010] In one possible implementation, the formula for calculating the coordinates of the third moving point is: Where M4 is the coordinate of the second moving point and M5 is the coordinate of the third moving point.

[0011] In one possible implementation, the formula for calculating the contact travel is: .

[0012] Compared with the prior art, the beneficial effects of this application are as follows: This application innovatively transforms the complex multi-link kinematics problem into a quadratic equation root-finding problem, reducing the calculation steps from the traditional 13 steps to 1 step, and improving the real-time performance to the 3ms level on the same hardware platform, fully meeting the real-time monitoring and control requirements of the circuit breaker opening and closing process.

[0013] This application uses rigorous kinematic modeling and vector rotation processing to control the stroke calculation error within 0.5%, effectively identifying subtle changes such as early spring fatigue and mechanism wear. Attached Figure Description

[0014] Figure 1 A flowchart illustrating a high-precision calculation method for circuit breaker stroke based on multi-link kinematic analysis provided in this application embodiment; Figure 2 A four-bar linkage model diagram provided for an embodiment of this application. Detailed Implementation

[0015] The present solution will now be described in conjunction with the accompanying drawings and specific embodiments.

[0016] Figure 1 A flowchart illustrating a high-precision calculation method for circuit breaker stroke based on multi-link kinematic analysis, provided for an embodiment of this application, is shown below. Figure 1 This application provides a high-precision calculation method for circuit breaker stroke based on multi-link kinematic analysis, comprising: S101 uses a non-invasive mechanical characteristic sensor installed inside the main shaft of the vacuum circuit breaker to collect the initial rotation angle of the main shaft in real time.

[0017] In this embodiment, the initial rotation angle of the main shaft of the circuit breaker is collected in real time by a non-invasive mechanical characteristic sensor, providing data support for judging the status of the circuit breaker mechanism.

[0018] S102, Establish a multi-link motion model of the circuit breaker transmission mechanism.

[0019] In this embodiment, a four-bar linkage motion model of the circuit breaker transmission mechanism is established. The main shaft of the circuit breaker is defined as the origin M1. The hinge point between the first and second links is the first moving point M2, the hinge point between the second and third links is the second moving point M3, the hinge point between the third and fourth links is the fixed point M4, and the hinge point between the fourth link and the pole tie rod is the third moving point M5. The length between M1 and M2 is the first distance L1, the length between M2 and M3 is the second distance L2, the length between M3 and M4 is the third distance L3, and the length between M4 and M5 is the fourth distance L4. The horizontal component of the fixed point M4 from the origin M1 is X, and the vertical component is Y. When the circuit breaker switches between opening and closing, the trajectory diagrams of the first moving point M2, the second moving point M3, and the third moving point M5 are drawn.

[0020] S103, input the initial rotation angle of the main shaft of the circuit breaker into the multi-link motion model, and calculate the coordinates of the first moving point.

[0021] In this embodiment, the formula for calculating the coordinates of the first moving point is: ,in, The distance between the origin and the first moving point. This is the initial rotation angle of the circuit breaker's spindle.

[0022] S104. Based on the principle of the intersection of two circles, a quadratic equation is established and solved to obtain the coordinates of the second moving point.

[0023] In this embodiment, the initial rotation angle of the circuit breaker's main shaft, the coordinates of the first moving point, the coordinates of the fixed point, the length of the second link, and the length of the third link are obtained. This is equivalent to M3 being one of the intersection points of the two circles M2 and M4. Based on the initial rotation angle of the circuit breaker's main shaft, the coordinates of the first moving point, the coordinates of the fixed point, the length of the second link, and the length of the third link, an equation is established, and the calculation formula is as follows: in, Let these be the coordinates of the second moving point. Let these be the coordinates of the first moving point. For fixed point coordinates, The length of the second link. The length of the third link. The distance between the origin and the first moving point. Let the initial rotation angle of the circuit breaker's main shaft be denoted as . The established equation is simplified to obtain a quadratic equation about the x-coordinate of the second moving point. The calculation formula is as follows: in, The coordinates of the second moving point are obtained by solving the quadratic equation using the following formula: .

[0024] S105, the contact stroke is calculated by combining the coordinates of the second moving point with the coordinates of the fixed point through vector rotation.

[0025] In this embodiment, the coordinates of the fixed point and the angle between the third and fourth links are obtained. The vector between the second moving point and the fixed point is calculated using the following formula: Using vector rotation, the angle between the third and fourth links is scaled to the distance between the fixed point and the third moving point. The calculation formula is as follows: Where c is the angle between the third and fourth links. Let these be the coordinates of the second moving point. For fixed point coordinates, The length of the third link. The length between the fixed point and the third moving point; The coordinates of the third moving point are calculated based on the vector between the fixed point and the third moving point; the formula for calculating the coordinates of the third moving point is: Where M4 is the coordinate of the second moving point and M5 is the coordinate of the third moving point.

[0026] Extract the y-coordinate of the third moving point, and use the y-coordinate of the third moving point as the contact stroke of the circuit breaker. The formula for calculating the contact stroke is: .

[0027] Furthermore, the travel sensor, based on infrared ranging, can measure the displacement travel of the circuit breaker, according to the formula: L=S 断路器试验位置测距值 -S 断路器工作位置测距值 -L 静触头前边沿与活门距离 -L 活门与断路器 The insertion depth of the plum blossom contact is calculated to provide support for the temperature sensor to detect over-temperature and over-limit conditions. A spring clamping force sensor is installed on the plum blossom contact, and is based on the formula: F is calculated as the pressure of a single finger of the plum blossom contact to reflect the current clamping force of the plum blossom contact spring. In the formula, n is the number of springs, k is the spring stiffness coefficient, D is the diameter of the spring bound to the plum blossom contact, L is the length of the spring in its natural state, and m is the number of finger pieces of the plum blossom contact.

[0028] In this embodiment, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, or the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0029] It should be noted that, in this document, 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 a 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 said element.

[0030] The above description is merely a specific embodiment of this application. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application. The protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A high-precision calculation method for circuit breaker stroke based on multi-link kinematic analysis, characterized in that, include: The initial rotation angle of the circuit breaker's main shaft is collected in real time by a non-invasive mechanical characteristic sensor installed inside the main shaft of the vacuum circuit breaker. Establish a multi-link motion model of the circuit breaker transmission mechanism; The initial rotation angle of the main shaft of the circuit breaker is collected and input into the multi-link motion model to calculate the coordinates of the first moving point; Based on the principle of the intersection of two circles, a quadratic equation is established and solved to obtain the coordinates of the second moving point; The contact stroke is calculated by combining the coordinates of the second moving point with the coordinates of the fixed point through vector rotation.

2. The high-precision calculation method for circuit breaker stroke based on multi-link kinematic analysis according to claim 1, characterized in that, The establishment of the multi-link motion model of the circuit breaker transmission mechanism includes: Define the main shaft of the circuit breaker as the origin; The hinge point between the first link and the second link is the first moving point; the hinge point between the second link and the third link is the second moving point; the hinge point between the third link and the fourth link is the fixed point; and the hinge point between the fourth link and the pole rod is the third moving point. The distance between the origin and the first moving point is the first distance, the distance between the first moving point and the second moving point is the second distance, the distance between the second moving point and the fixed point is the third distance, the distance between the fixed point and the third moving point is the fourth distance, and the horizontal component of the distance between the fixed point and the origin is X, and the vertical component is Y. When switching between opening and closing, the trajectory diagrams of the first moving point, the second moving point, and the third moving point are drawn.

3. The high-precision calculation method for circuit breaker stroke based on multi-link kinematic analysis according to claim 1, characterized in that, The formula for calculating the coordinates of the first moving point is: in, The distance between the origin and the first moving point. This is the initial rotation angle of the circuit breaker's spindle.

4. The high-precision calculation method for circuit breaker stroke based on multi-link kinematic analysis according to claim 1, characterized in that, The process of establishing and solving a quadratic equation based on the principle of intersection of two circles to obtain the coordinates of the second moving point includes: Obtain the initial rotation angle of the circuit breaker's main shaft, the coordinates of the first moving point, the coordinates of the fixed point, the length of the second link, and the length of the third link; Based on the initial rotation angle of the circuit breaker's main shaft, the coordinates of the first moving point, the coordinates of the fixed point, the length of the second link, and the length of the third link, an equation is established, and the calculation formula is as follows: in, Let these be the coordinates of the second moving point. Let these be the coordinates of the first moving point. For fixed point coordinates, The length of the second link. The length of the third link. The distance between the origin and the first moving point. This is the initial rotation angle of the circuit breaker's spindle; The equation is simplified to obtain a quadratic equation about the x-coordinate of the second moving point. The calculation formula is as follows: in, The coordinates of the second moving point are obtained by solving the quadratic equation using the following formula: 。 5. The high-precision calculation method for circuit breaker stroke based on multi-link kinematic analysis according to claim 1, characterized in that, Based on the coordinates of the second moving point and the coordinates of the fixed point, the contact stroke is calculated through vector rotation, including: Obtain the coordinates of the fixed point and the angle between the third and fourth links; The vector between the second moving point and the fixed point is calculated using the following formula: Using vector rotation, the angle between the third and fourth links is scaled to the distance between the fixed point and the third moving point. The calculation formula is as follows: Where c is the angle between the third and fourth links. Let these be the coordinates of the second moving point. For fixed point coordinates, The length of the third link. The distance between the fixed point and the third moving point; The coordinates of the third moving point are calculated based on the vector between the fixed point and the third moving point; Extract the y-coordinate of the third moving point and use the y-coordinate of the third moving point as the contact stroke of the circuit breaker.

6. The high-precision calculation method for circuit breaker stroke based on multi-link kinematic analysis according to claim 5, characterized in that, The formula for calculating the coordinates of the third moving point is: Where M4 is the coordinate of the second moving point and M5 is the coordinate of the third moving point.

7. The high-precision calculation method for circuit breaker stroke based on multi-link kinematic analysis according to claim 5, characterized in that, The formula for calculating the contact stroke is: 。

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