Optimization design method of combined iron core transformer

Abstract

The invention relates to the technical field of transformer iron core design, and particularly discloses a combined iron core transformer optimization design method which comprises the following steps: firstly, obtaining core parameters of reference silicon steel, high-performance silicon steel and common silicon steel and transformer load parameters, and calculating a total loss reference value of the reference silicon steel; setting two silicon steel area proportion initial values, and checking whether the two silicon steel area proportion initial values meet the saturation flux constraint and the area proportion constraint or not; constructing a dual-objective optimization model, and respectively taking the minimum loss when the cost is consistent with the reference silicon steel and the minimum cost when the loss is consistent with the reference silicon steel as objectives; and outputting the optimal objective function value and the corresponding silicon steel ratio, total mixing loss and unit cost. According to the method, dynamic load characteristics are coupled, precise balance of cost and loss is achieved through dual-objective optimization, the design process is efficient and controllable, the method is suitable for various power distribution and power transformer iron core designs, the comprehensive cost or operation loss of the transformer can be remarkably reduced, and the dual requirements for energy efficiency improvement and engineering economy are met.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and specifically to an optimized design method for a combined iron core transformer. Background Technology

[0002] As a core hub for power transmission and transformation in a power system, the transformer's operating efficiency and life-cycle cost are directly related to the power grid's energy-saving level and engineering economics. It is a key link in reducing losses and increasing efficiency in the power system under the "dual carbon" target. Transformer losses account for 30%-60% of total power grid losses, with core losses (including no-load losses and additional losses) accounting for over 60%. Therefore, the selection and proportioning design of core materials have a decisive impact on the overall performance of transformers. Currently, transformer cores mostly use a single grade of silicon steel, presenting a contradiction: "high-grade silicon steel has low losses but high costs, while low-grade silicon steel has low costs but high losses."

[0003] Existing hybrid silicon steel design methods often focus on single-objective optimization (such as reducing losses or controlling costs only), lacking a systematic balance between the dual objectives of "cost and loss." Furthermore, they fail to incorporate load fluctuation characteristics (such as the time-varying difference between rated and peak loads) for precise matching, leading to a mismatch between optimization results and actual operating conditions. In addition, traditional design methods rely on empirical adjustments, making it difficult to find the optimal solution in a multi-parameter space, resulting in low design efficiency and poor adaptability.

[0004] To address this, a combined core transformer optimization design method is proposed, which integrates load fluctuation characteristics and cost analysis. By combining high-performance silicon steel with ordinary silicon steel, the method achieves dual-objective optimization of "cost parity and loss reduction" or "loss parity and cost reduction" while meeting engineering constraints, providing a precise and efficient solution for transformer core design. Summary of the Invention

[0005] The purpose of this invention is to provide an optimized design method for combined iron-core transformers, aiming to solve the technical problems of single objective, poor adaptability, and low efficiency in existing hybrid silicon steel designs. To achieve the above objective, the specific technical solution is as follows: S1. Based on the required transformer model and specifications, obtain the core parameters of the three types of silicon steel and the transformer load parameters, and calculate the reference total loss benchmark value of the silicon steel. S2. Determine the unit cost, loss density and saturation flux density parameters of the two types of silicon steel, and ensure that the saturation flux constraint conditions are met. S3. Simplify the transformer load curve into an equivalent two-dimensional rectangular load to obtain its rated load and peak load duration distribution; S4. Based on the obtained parameters, construct two target optimization models: the minimum loss with cost matching the reference silicon steel and the minimum cost with loss matching the reference silicon steel. S5. Calculate the optimal area ratio based on the objective function, and obtain the silicon steel ratio scheme under different working conditions by gradually adjusting the parameter combination. S6. Output the minimum objective function, as well as the corresponding area ratio of high-performance silicon steel and ordinary silicon steel, the total loss of the combined iron core transformer, and the unit cost.

[0006] As a further aspect of the present invention: the core parameters of the three types of silicon steel in S1 include: the unit cost of reference silicon steel material 0, high-performance silicon steel material 1, and ordinary silicon steel material 2. , , Three types of silicon steel density , , Rated magnetic flux density B n Loss density P n0 , P n1 , P n2 Peak magnetic flux density B p Loss density P p0 , P p1 , P p2 Load parameters include the rated load factor. K 1. Peak load factor K 2. Peak duration t .

[0007] As a further aspect of the present invention: the calculation expression for the reference silicon steel material's total loss benchmark value is as follows: Where 24-t is the duration of rated load on a single day, and t is the duration of peak load.

[0008] As a further aspect of the present invention: the constraint condition of S2 includes a silicon steel saturation magnetic flux constraint condition, the expression of which is: Wherein, Bs1 and Bs2 are the saturation magnetic flux densities of high-performance silicon steel material 1 and ordinary silicon steel material 2, respectively. Peak magnetic flux density, K 1. K 2 represents the rated load factor and the peak load factor, respectively.

[0009] As a further aspect of the present invention: the objective function expression for minimizing the cost and loss of the reference silicon steel material 0 in S4 is as follows: in, k This represents the percentage of high-performance silicon steel in the area.

[0010] As a further aspect of the present invention: the objective function expression for minimizing the cost in S4, where the loss is consistent with that of the reference silicon steel material 0, is as follows: .

[0011] Compared with the prior art, the beneficial effects of the present invention are: The coupled dynamic load characteristics of this invention, through the complementary combination of "high-performance silicon steel + ordinary silicon steel", achieve dual-objective optimization of "cost parity and loss reduction" or "loss parity and cost reduction" under the premise of meeting engineering constraints. The design process is efficient and controllable, and it is suitable for the core design of various power distribution and power transformers. It provides a precise and efficient solution for transformer core design, which can significantly reduce the overall cost and operating loss of transformers and meet the dual requirements of energy efficiency improvement and engineering economy. Attached Figure Description

[0012] Figure 1 Flowchart of optimized design method for combined iron core transformers; Figure 2 This is a structural diagram of a combined iron-core transformer; Figure 3 A schematic diagram for obtaining the loss density of silicon steel; Figure 4 This is a schematic diagram of an equivalent two-dimensional rectangular load. Detailed Implementation

[0013] To enable those skilled in the art to better understand the technical solutions of the present invention, and to make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings of the embodiments.

[0014] Please see Figure 2 As shown, the purpose of this invention is to design a combined iron-core transformer that balances cost and losses while meeting actual operating conditions, such as... Figure 2 The diagram shows the structure of the combined core of the transformer. Due to the difference in magnetic permeability between different materials, the magnetic flux distribution is uneven. Normal magnetic flux is generated at the interface between the two materials, resulting in additional eddy current losses. The magnetic flux density is larger in the central area of ​​the transformer core. Therefore, high-performance silicon steel is placed in the center and ordinary silicon steel is placed in the edge area.

[0015] Please see Figure 1 As shown, this invention proposes a combined core transformer optimization design method that integrates load fluctuation characteristics and cost analysis. By combining high-performance silicon steel with ordinary silicon steel, it achieves dual-objective optimization of "cost parity and loss reduction" or "loss parity and cost reduction" while meeting engineering constraints, providing a precise and efficient solution for transformer core design.

[0016] Specifically, the above method includes at least the following steps: S1. Based on the required transformer model and specifications, obtain the core parameters of the three types of silicon steel and the transformer load parameters, and calculate the reference total loss benchmark value for the silicon steel: Key parameters include: unit cost of reference silicon steel material 0, high-performance silicon steel material 1, and ordinary silicon steel material 2. , , Three types of silicon steel density , , Rated magnetic flux density B n Loss density P n0 , P n1 , P n2 Peak magnetic flux density B p Loss density P p0 , P p1 , P p2 ; Load parameters include: rated load factor K 1. Peak load factor K 2. Peak duration t Refer to the formula for calculating the total loss benchmark value of silicon steel material: .

[0017] S2. Specify the unit cost, loss density, and saturation flux density parameters for both types of silicon steel under rated and peak load conditions, and ensure that the saturation flux constraint conditions are met: in, B s1 and B s2 These are the saturation magnetic flux densities of high-performance silicon steel and ordinary silicon steel, respectively. Peak magnetic flux density, K1. K 2 represents the rated load factor and the peak load factor, respectively. k The proportion of high-performance silicon steel.

[0018] S3. Simplify the transformer load curve into an equivalent two-dimensional rectangular load to obtain the duration distribution of its rated load and peak load.

[0019] S4. Based on the obtained parameters, construct two objective optimization models: one for minimizing loss while maintaining cost consistency with reference silicon steel, and the other for minimizing cost while maintaining loss consistency with reference silicon steel. S401, Objective Function 1: Cost Break-Even and Loss Reduction ； S402, Objective Function 2: Maintaining cost parity and reducing costs 。

[0020] S5. Calculate the optimal area ratio based on the objective function, and obtain the silicon steel proportioning scheme under different working conditions by gradually adjusting the parameter combination: S501, Set the iteration step size: k =0.01 is the adjustment step size, covering 0.1 ≤ k Feasible range ≤0.9 (excluding extreme proportions to ensure mixed meaning); S502, for each iteration step size corresponding to k Substitute into the objective function to calculate the corresponding P 12 or C 12 ; S503. Among the results that satisfy the constraints, select the k corresponding to the minimum value of the objective function, which is the optimal area ratio.

[0021] S6. Output the minimum objective function, along with the corresponding area ratio of high-performance silicon steel to ordinary silicon steel, the total loss of the combined core transformer, and the unit cost. Select the combination with lower cost or loss than the reference silicon steel for output.

[0022] Please see Figure 3 The diagram shown illustrates the acquisition of the loss density of silicon steel material, used to obtain the loss density of silicon steel at rated magnetic flux and peak magnetic flux.

[0023] Please see Figure 4 The diagram shown is a schematic of a two-dimensional rectangular load equivalent to the daily load. The rated load factor can be obtained from this diagram. K 1. Peak load factor K 2. Peak duration t The area marked in the figure must satisfy the following formula: .

[0024] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for optimizing the design of a combined core transformer, characterized in that, The method comprises the following steps: S1, according to the required design transformer model specification, obtain the core parameters of three silicon steels and transformer load parameters, calculate the total loss reference value of the reference silicon steel; S2, the unit cost of two kinds of silicon steel, the loss density of rated operation and peak load operation, and the saturation magnetic flux density parameters are determined, and the saturation magnetic flux constraint condition needs to be met; S3, the transformer load curve is simplified as an equivalent two-stage rectangular load, and the rated load and peak load time distribution are obtained; S4, two target optimization models are constructed according to the obtained parameters, which are cost and minimum consistent loss of reference silicon steel and minimum consistent cost of loss and reference silicon steel; S5, the optimal area ratio is calculated according to the objective function, and the silicon steel ratio scheme under different working conditions is obtained by gradually adjusting the parameter combination; S6, output the minimum objective function, and the corresponding high-performance silicon steel and ordinary silicon steel area ratio, combined core transformer total loss and unit cost.

2. The method of claim 1, wherein, The core parameters of the three silicon steels of S1 include: unit cost of reference silicon steel material 0, high-performance silicon steel material 1, and ordinary silicon steel material 2 、 、 ; the densities of the three silicon steels 、 、 ; the loss densities under the rated magnetic flux density B n 、 P n0 、 P n1 、 P n2 , the peak magnetic flux density B p 、 P p0 、 P p1 、 P p2 ; the load parameters include the rated load coefficient K 1, the peak load coefficient K 2, and the peak duration t .

3. The method of claim 2, wherein, The total loss reference value calculation expression of the reference silicon steel material 0 is: Wherein, 24-t is the single-day rated load duration, and t is the peak load duration.

4. The method of claim 2, wherein, The constraint condition of S2 includes the silicon steel saturation magnetic flux constraint condition, and the expression is: Wherein, Bs1 and Bs2 are the saturation magnetic flux density of high-performance silicon steel material 1 and ordinary silicon steel material 2 respectively, Bpk is the peak magnetic flux density, K 1, K 2 are the rated load factor and the peak load factor respectively.

5. The method of claim 2, wherein, The target function expression of S4 in which the cost and the consistent loss of the reference silicon steel material 0 are minimum: wherein, k is the high-performance silicon steel area ratio.

6. The method of claim 5, wherein, The target function expression of S4 in which the loss and the consistent cost of the reference silicon steel material 0 are minimum: 。

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