Optimization method and device for permanent magnet mechanism in circuit breaker

Abstract

The present invention provides an optimization method and device for a permanent magnetic mechanism in a circuit breaker, and belongs to the technical field of circuit breakers. The method comprises: obtaining parameters of a target circuit breaker; determining the residual magnetic flux density and relative magnetic permeability of each finite element based on the parameters of the target circuit breaker, and determining the average magnetic field in the Y-axis direction in a high-field strength cavity according to the residual magnetic flux density and relative magnetic permeability of each finite element; establishing an optimization model for a permanent magnetic mechanism with the minimum average magnetic field in the Y-axis direction in the high-field strength cavity as the objective function; solving the optimization model for the permanent magnetic mechanism to obtain the design parameters of the permanent magnetic mechanism of the target circuit breaker. The present invention optimizes the design parameters of the permanent magnetic mechanism of the circuit breaker, so that the permanent magnetic mechanism of the circuit breaker is more reasonable, and can effectively improve the performance of the vacuum circuit breaker.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breakers, and in particular to an optimization method and device for a permanent magnet mechanism in a circuit breaker. Background Art

[0002] The vacuum circuit breaker with permanent magnet mechanism is an important component of the power system. It has the advantages of small size, light weight, suitable for frequent operation, and arc extinguishing without maintenance. It is widely used in the power system.

[0003] The permanent magnet mechanism in the vacuum circuit breaker is used to limit the position of the opening and closing operating lever when closing or opening the circuit breaker. In conjunction with the reset spring, it can achieve rapid closing or opening operations. The parameters of the permanent magnet mechanism have a certain influence on the position and opening and closing speed of the opening and closing operating lever of the vacuum circuit breaker, thereby affecting the performance of the vacuum circuit breaker.

[0004] In the prior art, the parameters of the permanent magnet mechanism in the vacuum circuit breaker with the permanent magnet mechanism are fixed, which affects the improvement of the performance of the vacuum circuit breaker with the permanent magnet mechanism. Summary of the invention

[0005] The embodiment of the present invention provides a method and device for optimizing a permanent magnet mechanism in a circuit breaker, so as to solve the problem that the parameters of the permanent magnet mechanism of a vacuum circuit breaker are fixed, thus affecting the performance of the circuit breaker.

[0006] In a first aspect, an embodiment of the present invention provides a method for optimizing a permanent magnet mechanism in a circuit breaker, comprising:

[0007] Get the parameters of the target circuit breaker;

[0008] Determine the residual magnetic flux density and relative magnetic permeability of each finite element based on the parameters of the target circuit breaker, and determine the average magnetic field in the Y-axis direction in the high-field strength cavity according to the residual magnetic flux density and relative magnetic permeability of each finite element;

[0009] Taking the minimum average magnetic field in the Y-axis direction in the high-field cavity as the objective function, an optimization model of the permanent magnet mechanism is established.

[0010] The optimization model of the permanent magnet mechanism is solved to obtain the design parameters of the permanent magnet mechanism of the target circuit breaker.

[0011] In a second aspect, an embodiment of the present invention provides an optimization device for a permanent magnet mechanism in a circuit breaker, comprising:

[0012] A parameter acquisition module, used to obtain the parameters of the target circuit breaker;

[0013] A magnetic field calculation module, used to determine the residual magnetic flux density and relative magnetic permeability of each finite element based on the parameters of the target circuit breaker, and determine the average magnetic field in the Y-axis direction in the high-field strength cavity according to the residual magnetic flux density and relative magnetic permeability of each finite element;

[0014] A model building module is used to establish a permanent magnet mechanism optimization model with the minimum average magnetic field in the Y-axis direction in the high-field strength cavity as the objective function;

[0015] The solution module is used to solve the permanent magnet mechanism optimization model and obtain the permanent magnet mechanism design parameters of the target circuit breaker.

[0016] The embodiment of the present invention provides an optimization method and device for a permanent magnet mechanism in a circuit breaker. The method includes: obtaining the parameters of a target circuit breaker; determining the residual magnetic flux density and relative magnetic permeability of each finite element based on the parameters of the target circuit breaker, and determining the average magnetic field in the Y-axis direction in the high-field strength cavity according to the residual magnetic flux density and relative magnetic permeability of each finite element; establishing a permanent magnet mechanism optimization model with the minimum average magnetic field in the Y-axis direction in the high-field strength cavity as the objective function; solving the permanent magnet mechanism optimization model to obtain the permanent magnet mechanism design parameters of the target circuit breaker. In the embodiment of the present invention, a permanent magnet mechanism optimization model is established to optimize the design parameters of the permanent magnet mechanism of the circuit breaker, so that the permanent magnet mechanism of the circuit breaker is more reasonable and more in line with actual application requirements, which can effectively improve the performance of the vacuum circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 It is a flow chart of an implementation method of an optimization method of a permanent magnet mechanism in a circuit breaker provided by an embodiment of the present invention;

[0019] Figure 2 It is a schematic diagram of the relationship between the discrete angle penalty parameter and the number of iterations in the process of solving the permanent magnet mechanism optimization model provided by an embodiment of the present invention;

[0020] Figure 3 It is a schematic diagram of the relationship between the objective function and the number of iterations in the process of solving the permanent magnet mechanism optimization model provided by an embodiment of the present invention;

[0021] Figure 4 is a schematic diagram of magnetization direction within a design domain after optimization using the optimization method for a permanent magnet mechanism in a circuit breaker provided by an embodiment of the present invention;

[0022] Figure 5 It is a structural schematic diagram of an optimization device for a permanent magnet mechanism in a circuit breaker provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0025] See also Figure 1 , which shows a flow chart of the implementation of the optimization method of the permanent magnet mechanism in the circuit breaker provided by the embodiment of the present invention, and is described in detail as follows:

[0026] The optimization method of the permanent magnet mechanism in the above circuit breaker comprises:

[0027] S101: Obtain parameters of a target circuit breaker;

[0028] S102: determining the residual magnetic flux density and relative magnetic permeability of each finite element based on the parameters of the target circuit breaker, and determining the average magnetic field in the Y-axis direction in the high field strength cavity according to the residual magnetic flux density and relative magnetic permeability of each finite element;

[0029] S103: Taking the minimum average magnetic field in the Y-axis direction in the high-field strength cavity as the objective function, an optimization model of the permanent magnet mechanism is established;

[0030] S104: Solving the permanent magnet mechanism optimization model to obtain permanent magnet mechanism design parameters of the target circuit breaker.

[0031] For a circuit breaker with a permanent magnetic mechanism, when the power is off, the permanent magnetic mechanism can keep the circuit breaker in a closed state; when the power is on, the electromagnetic force will overcome the attraction of the permanent magnet, separate the mechanical part, thereby achieving power off and ensuring the safe operation of the circuit. Since the residual magnetic flux density and the relative magnetic permeability determine the performance of the magnetic material, the residual magnetic flux density and the relative magnetic permeability are determined in the embodiment of the present invention, and the permanent magnetic mechanism is optimized and designed. The average magnetic field in the Y-axis direction in the high-field strength cavity is minimized as the objective function, and an optimization model of the permanent magnetic mechanism is established, so that the design parameters of the permanent magnetic mechanism are optimized, the design is more reasonable, and it is more in line with the actual application requirements, so that the circuit breaker performance is more superior.

[0032] In a possible implementation manner, the permanent magnet mechanism design parameters of the target circuit breaker may include: a first density design variable, a second density design variable, a first direction design variable, a second direction design variable, and a discrete angle penalty parameter.

[0033] In the embodiment of the present invention, the permanent magnet mechanism design parameters are determined mainly based on the residual magnetic flux density and the relative magnetic permeability, and the above two parameters are mainly determined by the above-mentioned design parameters.

[0034] In a possible implementation, S102 may include:

[0035] S1021: taking the first density design variable, the second density design variable, the first direction design variable, the second direction design variable and the discrete angle penalty parameter as variables, and combining the parameters of the target circuit breaker, determining the residual flux density of each finite element;

[0036] S1022: Taking the first density design variable and the second density design variable as variables and combining them with parameters of the target circuit breaker, determine the relative magnetic permeability of each finite element.

[0037] The residual magnetic flux density is affected by the density parameter, the direction parameter and the maximum permanent magnetic strength, while the first density design variable and the second density design variable affect the density parameter, the first direction design variable and the second direction design variable affect the direction parameter, and the discrete angle penalty parameter affects the maximum permanent magnetic strength. Therefore, in the embodiment of the present invention, the first density design variable, the second density design variable, the first direction design variable, the second direction design variable and the discrete angle penalty parameter are used as variables to determine the residual magnetic flux density. At the same time, the relative magnetic permeability is mainly affected by the first density design variable and the second density design variable. Therefore, the first density design variable and the second density design variable are also used as variables to determine the relative magnetic permeability of each finite element.

[0038] In a possible implementation, S1021 may include:

[0039] 1. Take the discrete angle penalty parameter and permanent magnet direction parameter as variables to determine the maximum permanent magnet strength;

[0040] 2. According to the maximum permanent magnetic strength, the first density design variable, the second density design variable, the first direction design variable and the second direction design variable are combined with the parameters of the target circuit breaker to determine the residual flux density of each finite element.

[0041] In the embodiment of the present invention, the maximum permanent magnetic strength is first determined, and then the residual magnetic flux density is obtained according to the permanent magnetic strength.

[0042] In a possible implementation manner, the calculation formula for the residual magnetic flux density may be:

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052] in, Finite Element The residual flux density at is the maximum permanent magnetic strength, Finite Element The vector at ; Finite Element The density parameter at Finite Element Direction parameters at ; is the permanent magnet density penalty parameter, is the first density design variable, is the second density design variable, Design variables for the first direction, Design variables for the second direction.

[0053] The governing equations for magnetostatics involving permanent magnetic materials and ferromagnetic materials can be derived from Maxwell's equations as follows:

[0054]

[0055] in, is the relative magnetic permeability, is the vacuum permeability (which can be set to ), is the magnetic vector potential, Finite Element The residual flux density at .

[0056] From the above formula, we can deduce

[0057] Determines the magnetic field strength and magnetization direction, density parameters Determines the permanent magnet strength, Determines the magnetization direction of the permanent magnet.

[0058] is the permanent magnet density penalty parameter, which is generally a positive integer.

[0059] In a possible implementation, the calculation formula for the maximum permanent magnetic strength may be:

[0060]

[0061]

[0062]

[0063] in, is the maximum permanent magnetic strength, is the residual magnetic flux density of the permanent magnetic material, is the discrete angle penalty parameter, is the intermediate function, For the The minimum angle of the permanent magnet segment, For the The maximum angle of the permanent magnet segment, is the permanent magnet direction parameter, , is the number of permanent magnet segments.

[0064] The embodiment of the present invention proposes a scheme for constraining the intermediate magnetization direction angle, so that each permanent magnet segment corresponds to a single discrete magnetization direction angle, and the intermediate angles between the target angle sets are penalized by controlling the maximum permanent magnet strength, so that the permanent magnet strength can reach the maximum magnetic induction intensity at a specific angle.

[0065] The discrete angle set is ,For example, It can be 8, and the discrete angle set is (0, , ,..., ).

[0066] is the discrete angle penalty parameter, 1 means no penalty, then the maximum permanent magnetic strength is equal to , is a constant. When it decreases When , a stronger penalty will be imposed on the intermediate magnetization angle, which is suitable for finding the maximum magnetic field, that is, a larger permanent magnet strength Therefore, the optimal permanent magnet design is at the target angle set. largest, others have smaller The angle set is penalized, and through this mechanism, the optimal permanent magnet design is found, which shows the magnetization direction angle consistent with the target discrete angle set.

[0067] Discrete angle penalty parameter When it is small, the magnetization direction angle in the optimization result will be close to the discrete angle set; otherwise, the discrete angle penalty parameter When it is larger, the magnetization direction angle in the optimization result will be far away from the discrete angle set; at the same time, the discrete angle penalty parameter The size of will affect the accuracy and convergence speed of the optimization results. It cannot be set directly to the minimum value, otherwise the optimized structure will be inaccurate or the convergence speed will be slow. This will also result in the magnetic field in the cavity not being maximized, so in the optimization process Gradually decrease from 1.

[0068] Need to explain, is a position quantity.

[0069] In a possible implementation, the calculation formula for relative magnetic permeability may be:

[0070]

[0071]

[0072]

[0073] in, is the relative magnetic permeability, is the relative magnetic permeability of the air gap, is the relative magnetic permeability of pure iron, is the first density design variable, is the second density design variable, is the pure iron constraint parameter.

[0074] It should be noted that the pure iron constraint parameters is a positive real number.

[0075] Relative magnetic permeability The distribution of can be expressed as follows using the interpolation scheme based on magnetic resistivity:

[0076]

[0077] Density Design Variables and The permanent magnet strength and relative magnetic permeability are controlled simultaneously, so the proposed material interpolation scheme represents three materials: air gap, permanent magnet, and pure iron.

[0078] Based on the above, the optimal material distribution between multiple materials can be effectively calculated based on relative magnetic permeability and residual magnetic flux density.

[0079] In a possible implementation, the objective function may be:

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086] in, is the average magnetic field in the high field strength cavity along the Y axis, is the high field strength cavity area, is the magnetic induction intensity in the Y-axis direction, is the effective area, for and The functional relationship between is the stiffness matrix, is the force vector, is the magnetic vector potential, Design parameter sets for permanent magnet mechanisms, is the first density design variable, Design variable for the second density, Design variables for the first direction, Design variables for the second direction, is the discrete angle penalty parameter, is the volume of the permanent magnet, is the maximum volume of the permanent magnet, is the volume of pure iron, is the maximum volume of pure iron.

[0087] The design purpose of the embodiment of the present invention is to find the optimal permanent magnet segment and pure iron shape in the design to maximize the magnetic field in the cavity. Therefore, a model is established with the minimum average magnetic field in the Y-axis direction in the high-field strength cavity as the objective function to solve the problem.

[0088] In a possible implementation, S104 may include:

[0089] S1041: The global convergent moving asymptote method is used to solve the permanent magnet mechanism optimization model and obtain the permanent magnet mechanism design parameters of the target circuit breaker.

[0090] The above embodiment is described below in conjunction with specific embodiments. It can be 8, and the discrete angle set is (0, , ,..., ), the high field strength cavity area is 0.4, the design domain size is 4, and the relative magnetic permeability of pure iron is is 1500, pure iron constraint parameter is 1, permanent magnet density penalty parameter is 3, and the target permanent magnet volume and pure iron volume account for 15% and 10% of the total design domain, respectively.

[0091] The objective function is solved by the globally convergent moving asymptote method, and the discrete angle penalty parameter Gradually decrease, reference Figure 2 ; At the same time, the objective function Also gradually decreases, refer to Figure 3 , and finally calculated The maximum permanent magnetic strength is 0.043T. is 0.1T, the permanent magnet mechanism reaches the optimum, and the magnetization direction in the design domain is as follows Figure 4 shown.

[0092] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0093] The following is an embodiment of the device of the present invention. For details not described in detail therein, reference may be made to the corresponding method embodiment described above.

[0094] Figure 5 The structural schematic diagram of the optimization device of the permanent magnet mechanism in the circuit breaker provided by the embodiment of the present invention is shown. For the convenience of description, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0095] like Figure 5 As shown, the optimization device of the permanent magnet mechanism in the circuit breaker includes:

[0096] A parameter acquisition module 21, used to acquire parameters of a target circuit breaker;

[0097] A magnetic field calculation module 22, used to determine the residual magnetic flux density and relative magnetic permeability of each finite element based on the parameters of the target circuit breaker, and determine the average magnetic field in the Y-axis direction in the high field strength cavity according to the residual magnetic flux density and relative magnetic permeability of each finite element;

[0098] A model building module 23 is used to establish a permanent magnet mechanism optimization model by taking the minimum average magnetic field in the Y-axis direction in the high-field strength cavity as the objective function;

[0099] The solving module 24 is used to solve the permanent magnet mechanism optimization model to obtain the permanent magnet mechanism design parameters of the target circuit breaker.

[0100] In a possible implementation manner, the permanent magnet mechanism design parameters of the target circuit breaker may include: a first density design variable, a second density design variable, a first direction design variable, a second direction design variable, and a discrete angle penalty parameter.

[0101] In a possible implementation, the magnetic field calculation module 22 may include:

[0102] a first calculation unit, for determining the residual magnetic flux density of each finite element by taking the first density design variable, the second density design variable, the first direction design variable, the second direction design variable and the discrete angle penalty parameter as variables and combining the parameters of the target circuit breaker;

[0103] The second calculation unit is used to determine the relative magnetic permeability of each finite element by taking the first density design variable and the second density design variable as variables and combining the parameters of the target circuit breaker.

[0104] In a possible implementation, the first computing unit may be specifically configured to:

[0105] 1. Take the discrete angle penalty parameter and permanent magnet direction parameter as variables to determine the maximum permanent magnet strength;

[0106] 2. According to the maximum permanent magnetic strength, the first density design variable, the second density design variable, the first direction design variable and the second direction design variable are combined with the parameters of the target circuit breaker to determine the residual flux density of each finite element.

[0107] In a possible implementation manner, the calculation formula for the residual magnetic flux density may be:

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117] in, Finite Element The residual flux density at is the maximum permanent magnetic strength, Finite Element The vector at ; Finite Element The density parameter at Finite Element Direction parameters at ; is the permanent magnet density penalty parameter, is the first density design variable, is the second density design variable, Design variables for the first direction, Design variables for the second direction.

[0118] In a possible implementation, the calculation formula for the maximum permanent magnetic strength may be:

[0119]

[0120]

[0121]

[0122] in, is the maximum permanent magnetic strength, is the residual magnetic flux density of the permanent magnetic material, is the discrete angle penalty parameter, is the intermediate function, For the The minimum angle of the permanent magnet segment, For the The maximum angle of the permanent magnet segment, is the permanent magnet direction parameter, , is the number of permanent magnet segments.

[0123] In a possible implementation, the calculation formula for relative magnetic permeability may be:

[0124]

[0125]

[0126]

[0127] in, is the relative magnetic permeability, is the relative magnetic permeability of the air gap, is the relative magnetic permeability of pure iron, is the first density design variable, is the second density design variable, is the pure iron constraint parameter.

[0128] In a possible implementation, the objective function may be:

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135] in, is the average magnetic field in the high field strength cavity along the Y axis, is the high field strength cavity area, is the magnetic induction intensity in the Y-axis direction, is the effective area, for and The functional relationship between is the stiffness matrix, is the force vector, is the magnetic vector potential, Design parameter sets for permanent magnet mechanisms, is the first density design variable, Design variable for the second density, Design variables for the first direction, Design variables for the second direction, is the discrete angle penalty parameter, is the volume of the permanent magnet, is the maximum volume of the permanent magnet, is the volume of pure iron, is the maximum volume of pure iron.

[0136] In a possible implementation, the solving module 24 may be specifically used to solve the permanent magnet mechanism optimization model by using a globally convergent moving asymptote method to obtain the permanent magnet mechanism design parameters of the target circuit breaker.

[0137] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0138] Those of ordinary skill in the art will appreciate that the templates, units, and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0139] If the module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned optimization method embodiments of the permanent magnet mechanism in each circuit breaker can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. Computer-readable media can include: any entity or device that can carry computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory, random access memory, electrical carrier signal, telecommunication signal and software distribution medium.

[0140] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A method for optimizing a permanent magnet mechanism in a circuit breaker, characterized in that: include: Get the parameters of the target circuit breaker; Determine the residual magnetic flux density and relative magnetic permeability of each finite element based on the parameters of the target circuit breaker, and determine the average magnetic field in the Y-axis direction in the high-field strength cavity according to the residual magnetic flux density and relative magnetic permeability of each finite element; Taking the minimum average magnetic field in the Y-axis direction in the high-field strength cavity as the objective function, an optimization model of the permanent magnet mechanism is established; Solving the permanent magnet mechanism optimization model to obtain the permanent magnet mechanism design parameters of the target circuit breaker; The permanent magnet mechanism design parameters of the target circuit breaker include: a first density design variable, a second density design variable, a first direction design variable, a second direction design variable and a discrete angle penalty parameter; The determining of the residual magnetic flux density and the relative magnetic permeability of each finite element based on the parameters of the target circuit breaker comprises: Taking the first density design variable, the second density design variable, the first direction design variable, the second direction design variable and the discrete angle penalty parameter as variables, and combining the parameters of the target circuit breaker, determine the residual flux density of each finite element; Taking the first density design variable and the second density design variable as variables and combining the parameters of the target circuit breaker, determine the relative magnetic permeability of each finite element; The method of using the first density design variable, the second density design variable, the first direction design variable, the second direction design variable and the discrete angle penalty parameter as variables and combining the parameters of the target circuit breaker to determine the residual flux density of each finite element includes: Taking the discrete angle penalty parameter and the permanent magnet direction parameter as variables, determining the maximum permanent magnet strength; Determine the residual magnetic flux density of each finite element according to the maximum permanent magnetic intensity, the first density design variable, the second density design variable, the first direction design variable and the second direction design variable, and the parameters of the target circuit breaker; The calculation formula of the residual magnetic flux density is: p∈[-1,1] q∈[-1,1] k∈(0,1] l∈(0,1] in, Finite Element The residual flux density at is the maximum permanent magnetic strength, Finite Element The vector at ; Finite Element The density parameter at Finite Element β is the permanent magnet density penalty parameter, k is the first density design variable, l is the second density design variable, p is the first direction design variable, and q is the second direction design variable; The calculation formula of the maximum permanent magnetic strength is: m∈(0,1] in, is the maximum permanent magnetic strength, B res is the residual magnetic flux density of the permanent magnet material, m is the discrete angle penalty parameter, H i (θ) is the intermediate function, v i is the minimum angle of the i-th permanent magnet segment, v i+1 is the maximum angle of the i-th permanent magnet segment, θ is the permanent magnet direction parameter, i=1, ..., n, n is the number of permanent magnet segments; The calculation formula of the relative magnetic permeability is: k∈(0,1] l∈(0,1] Among them, μ m is the relative magnetic permeability, μ ag is the relative magnetic permeability of the air gap, μ Fe is the relative magnetic permeability of pure iron, k is the first density design variable, l is the second density design variable, and α is the pure iron constraint parameter; The objective function is: Wherein, φ is the average magnetic field in the Y-axis direction in the high field strength cavity, A f is the high field strength cavity area, B y is the magnetic induction intensity in the Y-axis direction, S is the effective area, and F(η) is B y The functional relationship between η and K() is the stiffness matrix, f() is the force vector, ω is the magnetic vector potential, η is the permanent magnet mechanism design parameter set, k is the first density design variable, l is the second density design variable, p is the first direction design variable, q is the second direction design variable, m is the discrete angle penalty parameter, V P is the volume of the permanent magnet, is the maximum volume of the permanent magnet, V Fe is the volume of pure iron, is the maximum volume of pure iron.

2. The method for optimizing the permanent magnet mechanism in a circuit breaker according to claim 1, characterized in that: The step of solving the permanent magnet mechanism optimization model to obtain the permanent magnet mechanism design parameters of the target circuit breaker includes: The permanent magnet mechanism optimization model is solved by using a globally convergent moving asymptote method to obtain the permanent magnet mechanism design parameters of the target circuit breaker.

3. An optimization device for a permanent magnet mechanism in a circuit breaker, characterized in that: include: A parameter acquisition module, used to obtain the parameters of the target circuit breaker; A magnetic field calculation module, used to determine the residual magnetic flux density and relative magnetic permeability of each finite element based on the parameters of the target circuit breaker, and determine the average magnetic field in the Y-axis direction in the high-field strength cavity according to the residual magnetic flux density and relative magnetic permeability of each finite element; A model building module, used to establish a permanent magnet mechanism optimization model with the minimum average magnetic field in the Y-axis direction in the high-field strength cavity as the objective function; A solution module, used for solving the permanent magnet mechanism optimization model to obtain the permanent magnet mechanism design parameters of the target circuit breaker; The permanent magnet mechanism design parameters of the target circuit breaker include: a first density design variable, a second density design variable, a first direction design variable, a second direction design variable and a discrete angle penalty parameter; The magnetic field calculation module comprises: a first calculation unit, configured to determine the residual magnetic flux density of each finite element by taking the first density design variable, the second density design variable, the first direction design variable, the second direction design variable and the discrete angle penalty parameter as variables and combining the parameters of the target circuit breaker; a second calculation unit, configured to determine a relative magnetic permeability of each finite element by taking the first density design variable and the second density design variable as variables and combining the parameters of the target circuit breaker; The first calculation unit is specifically used to: determine the maximum permanent magnet strength by taking the discrete angle penalty parameter and the permanent magnet direction parameter as variables; determine the residual flux density of each finite element according to the maximum permanent magnet strength, the first density design variable, the second density design variable, the first direction design variable and the second direction design variable, combined with the parameters of the target circuit breaker; The calculation formula of the residual magnetic flux density is: p∈[-1,1] q∈[-1,1] k∈(0,1] l∈(0,1] in, Finite Element The residual flux density at is the maximum permanent magnetic strength, Finite Element The vector at ; Finite Element The density parameter at Finite Element β is the permanent magnet density penalty parameter, k is the first density design variable, l is the second density design variable, p is the first direction design variable, and q is the second direction design variable; The calculation formula of the maximum permanent magnetic strength is: m∈(0,1] in, is the maximum permanent magnetic strength, B res is the residual magnetic flux density of the permanent magnet material, m is the discrete angle penalty parameter, H i (θ) is the intermediate function, v i is the minimum angle of the i-th permanent magnet segment, v i+1 is the maximum angle of the i-th permanent magnet segment, θ is the permanent magnet direction parameter, i=1, ..., n, n is the number of permanent magnet segments; The calculation formula of the relative magnetic permeability is: k∈(0,1] l∈(0,1] Among them, μ m is the relative magnetic permeability, μ ag is the relative magnetic permeability of the air gap, μ Fe is the relative magnetic permeability of pure iron, k is the first density design variable, l is the second density design variable, and α is the pure iron constraint parameter; The objective function is: B y =F(n) K(η)ω=f(η) η={klpqm} T Wherein, φ is the average magnetic field in the Y-axis direction in the high field strength cavity, A f is the high field strength cavity area, B y is the magnetic induction intensity in the Y-axis direction, S is the effective area, and F(η) is B y The functional relationship between η and K() is the stiffness matrix, f() is the force vector, ω is the magnetic vector potential, η is the permanent magnet mechanism design parameter set, k is the first density design variable, l is the second density design variable, p is the first direction design variable, q is the second direction design variable, m is the discrete angle penalty parameter, V P is the volume of the permanent magnet, is the maximum volume of the permanent magnet, V Fe is the volume of pure iron, is the maximum volume of pure iron.

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