A transformer core mixture calculation model based on ray method

Abstract

The application is a transformer core mixed material calculation model based on the ray method, a coordinate system is established according to the B-P curve of the mixed material silicon steel sheet grade, the discrete problem is linearized by the ray method according to the core design iron loss, a fuzzy membership calculation method is introduced, the fuzzy membership of each grade to the design iron loss is obtained, and the ray method power transformer core mixed material calculation model is iterated to obtain the weight of each grade silicon steel used for mixing. The application has the advantages that the model is reasonably designed, is a power transformer core mixed material calculation model which can quantitatively consider the discrete influence of material loss, and can provide quantitative material mixing guidance for actual production of core mixed material, reduce production cost and improve production efficiency.

Description

Technical Field

[0001] This invention relates to a calculation model for transformer core mixing based on the X-ray method, belonging to the field of power transformer core manufacturing. Background Technology

[0002] In power transmission projects, the cores of power transformers are manufactured using stacked silicon steel sheets. Practical production experience has shown that using a mixture of different grades of silicon steel sheets can save costs.

[0003] In existing technologies, the method of calculating iron loss based on the weight ratio of silicon steel grade and unit iron loss is used to guide production. However, due to large errors, it requires correction by combining sample production methods, leading to reduced efficiency and increased costs. Currently, there is a lack of mathematically meaningful guiding calculation models for the manufacture of iron cores using mixed materials.

[0004] To construct the aforementioned guiding calculation model, based on the BP loss curves of different grades of silicon steel used in core manufacturing, and considering the discrete characteristics of loss values ​​of adjacent grades of silicon steel, the ray method is adopted to linearize the discrete problem. At the same time, the fuzzy membership degree calculation method is introduced to establish a calculation model for mixed materials of power transformer cores based on the ray method, which can provide a complete set of guiding methods for calculating mixed materials in power transformer manufacturing. Summary of the Invention

[0005] This invention proposes a calculation model for transformer core mixing based on the ray method, which aims to fill the aforementioned gaps in the existing technology and be applied to the actual production guidance of power transformer mixing and counterweight.

[0006] The technical solution of this invention is as follows: A coordinate system is established based on the BP loss curve of the silicon steel sheet grade used in the mixed material. The discrete problem is linearized by using the ray method according to the core design iron loss. At the same time, a fuzzy membership degree calculation method is introduced to obtain the fuzzy membership degree of each grade to the design iron loss. The model is iteratively fed into a power transformer core mixed material calculation model based on the ray method to calculate the weight of each grade of silicon steel used in the mixed material.

[0007] Specifically, the following steps are included:

[0008] 1) Plot the BP loss curves of silicon steel materials of grades 1, 2, 3 to n in a coordinate system according to the magnetic flux density range of 1.8T-0.4T, as shown below. Figure 1 As shown;

[0009] 2) Establish point P0 on the coordinate graph with the core design magnetic flux density T0 and unit iron loss as the x and y axes, such as... Figure 1 As shown;

[0010] 3) A ray is drawn from the origin through point P0, intersecting the BP loss curves of grades 1, 2, 3, ..., n at points P1, P2, P3, ..., Pn. n Point, such as Figure 1 As shown;

[0011] 4) Calculate the line segments P1P2, P2P3, and P... m P0, P0P m+1 ... P n-1 P n and P1P n Length (point P0 lies between the loss curves of grade m and grade m+1);

[0012] 5) The fuzzy membership gradient value α of silicon steel grade i mixture is calculated using Formula 1. i :

[0013]

[0014] In the formula: α i For silicon steel grade i, the fuzzy membership gradient value of iron loss P0 corresponding to the design unit is given.

[0015] 6) Substituting the above parameters into Formula 2, we obtain the core manufacturing weight corresponding to silicon steel grade i:

[0016]

[0017] Where: m i The weight of the mixture is α, where i is the silicon steel grade and α is the weight of the mixed materials. i Let i be the fuzzy membership gradient value of silicon steel grade, and G be the total design weight of the core.

[0018] The advantages of this invention are: the model is reasonably designed and is a quantitative calculation model for mixed materials used in power transformer cores that simultaneously considers the discrete effects of material losses. This model can provide quantitative material allocation guidance for the actual production of mixed materials for cores, thereby reducing production costs and improving production efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the application of the calculation model for transformer core mixing based on the ray method of this invention.

[0020] Figure 2 This is a schematic diagram illustrating an embodiment of the calculation model for transformer core mixing based on the ray method of the present invention. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to embodiments and specific implementation methods. Example

[0022] A detailed implementation method for a calculation model of core mixing of a 10kV oil distribution transformer based on the ray method.

[0023] The core is designed to weigh 590 kg. The material used is a mixture of three silicon steel grades: 75, 80, and 90, from a certain steel mill. The design magnetic flux density is 1.4 T, corresponding to a design unit iron loss P0 = 0.426 W / kg.

[0024] 1) Plot the BP curves of steel grades 75, 80, and 90 from a certain steel mill according to the range of 1.8-0.4T, as shown in the figure. Figure 2 As shown;

[0025] 2) Establish the coordinate point P0 (1.4, 0.426) on the coordinate graph, such as... Figure 2 As shown;

[0026] 3) Draw a ray from the origin through point P0, intersecting the BP loss curves of 75, 80, and 90 silicon steel grades at points P1, P2, and P3, respectively. Figure 2 As shown;

[0027] 4) The calculated line segment lengths are P1P0=0.0276, P0P2=0.0297, P2P3=0.0432, and P1P3=0.1005;

[0028] 5) Substituting into Formula 1, we obtain the fuzzy membership gradient values ​​for materials 75, 80, and 90 as 0.27, 0.30, and 0.43, respectively.

[0029] ;

[0030] 6) Substituting into the calculation model (Protocol 2), we get the material consumption as follows: 159.3 kg for 75 grade, 177 kg for 80 grade, and 253.7 kg for 90 grade.

[0031] .

[0032] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A calculation model for transformer core mixing based on the ray-mapping method, characterized in that, include: A coordinate system is established based on the BP loss curve of the silicon steel sheet grade used in the mixed material. The discrete problem is linearized by the ray method according to the iron loss of the core design. The fuzzy membership degree calculation method is introduced to obtain the fuzzy membership degree of each grade to the design iron loss. The fuzzy membership degree of each grade of silicon steel is iterated into the calculation model to calculate the weight of each grade of silicon steel used in the mixed material. The establishment of a coordinate system based on the BP loss curve of the silicon steel sheet used in the mixture includes plotting the BP loss curves of silicon steel materials of grades 1, 2, 3 to n in the coordinate system according to the magnetic flux density range of 1.8T-0.4T. The method of linearizing the discrete problem based on the iron loss design of the iron core using the ray casting method includes: Establish point P0 on the coordinate graph with the core design magnetic flux density T0 and unit iron loss as the horizontal and vertical axes; A ray is drawn from the origin at point P0, intersecting the BP loss curves of grades 1, 2, 3, ..., n at points P1, P2, P3, ..., Pn. n point; The line segments P1P2, P2P3, and P are calculated. m P0, P0P m+1 ... P n-1 P n and P1P n length; The method for calculating fuzzy membership degree is introduced to obtain the fuzzy membership degree of each grade to the design iron loss, including the fuzzy membership gradient value α of silicon steel grade i mixed with other materials calculated by formula (1). i : ， In the formula: α i For silicon steel grade i, the fuzzy membership gradient value of iron loss P0 corresponding to the design unit is given. The iterative calculation model is used to calculate the weight of each grade of silicon steel used in the mixed materials, including substituting the obtained parameters into formula (2) to obtain the weight of silicon steel grade i corresponding to the core manufacturing weight: ， Where: m i The weight of the mixture is α, where i is the silicon steel grade and α is the weight of the mixed materials. i Let i be the fuzzy membership gradient value of silicon steel grade i, and G be the total design weight of the iron core. The P0 point is located between the loss curves of grade m and grade m+1.

Images