Design method of transformer winding, PCB transformer and power supply module

Abstract

The present invention provides a design method for a transformer winding, a PCB transformer and a power module, wherein: the design method includes: determining a set of excitation coefficients for the transformer winding based on the turns ratio of the transformer winding; performing a full permutation on each excitation coefficient in the set of excitation coefficients to obtain a number of non-repeating permutation sequences and form a coefficient matrix; performing a stage summation operation on the coefficient matrix to obtain a stage summation matrix; obtaining a first matrix and / or a second matrix based on the stage summation matrix, and thereby obtaining an optimal stacking method for the transformer winding. Through the design method for the transformer winding, the PCB transformer and the power module provided by the present invention, the problem that the traditional sandwich winding stacking method is prone to high transformer losses is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and particularly to a design method for a transformer winding, a PCB transformer, and a power supply module. Background Art

[0002] In a high-power density power supply module, as a core component, the performance of a PCB transformer directly affects the efficiency and thermal stability of the power supply module. The losses of a PCB transformer mainly consist of the hysteresis loss, eddy current loss, and residual loss of the transformer, as well as the AC loss and DC loss of the winding, and these losses are closely related to the magnetization process of the transformer material.

[0003] In high-frequency applications, the problem of transformer loss is particularly prominent because high-frequency magnetic fields will cause large hysteresis loops and eddy currents inside the transformer material, thereby increasing losses. In the prior art, a sandwich-type winding lamination structure (alternately laminating the primary winding and the secondary winding) is usually adopted to reduce transformer losses. However, this winding lamination method has the following defects.

[0004] First, there is a lack of a systematic design method. The design of the traditional sandwich-type winding lamination structure mainly relies on experience and simulation feedback, resulting in low design efficiency and difficulty in achieving optimal performance.

[0005] Second, the magnetic field distribution is uneven. The layout of the traditional sandwich-type winding lamination structure is likely to cause uneven distribution of the magnetic field intensity of the transformer, and the magnetic induction intensity in local areas is too high, exacerbating transformer losses.

[0006] Third, the thermal coupling problem is prominent. The heat generated by the transformer loss and the winding loss is coupled with each other, resulting in an increase in temperature rise, further increasing the total loss, and reducing the reliability of the power supply module.

[0007] Fourth, the high-frequency adaptability is poor. As the operating frequency increases (for example, from 200KHz to 1MHz), in the traditional sandwich-type winding lamination structure, due to the significant skin effect and proximity effect, the winding current distribution is uneven, and the transformer loss increases exponentially, making it difficult to meet the requirements of high-frequency power supply modules.

[0008] It should be noted that the above introduction of the technical background is only for the convenience of clearly and completely explaining the technical solution of the present invention and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well-known to those skilled in the art just because these solutions are described in the background art part of the present invention. Summary of the Invention

[0009] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a design method for a transformer winding, a PCB transformer and a power module, which are used to solve the problem that the traditional sandwich winding stacking method is likely to cause high transformer losses.

[0010] To achieve the above object and other related objects, the present invention provides a design method for a transformer winding, and the design method includes:

[0011] Based on the turns ratio of the transformer winding, determine the set of exciting coefficients of the transformer winding;

[0012] Perform a full permutation on each exciting coefficient in the set of exciting coefficients to obtain a number of non-repeated permutation sequences and form a coefficient matrix;

[0013] Perform a stage summation operation on the coefficient matrix to obtain a stage summation matrix;

[0014] Based on the stage summation matrix, obtain the first matrix and / or the second matrix, and thereby obtain the optimal stacking method of the transformer winding.

[0015] Optionally, the method for determining the set of exciting coefficients includes: based on the turns ratio of the transformer winding, obtain the exciting coefficient of the primary single-turn winding and the exciting coefficient of the secondary single-turn winding of the transformer winding, and thereby construct the set of exciting coefficients.

[0016] Optionally, the exciting coefficient of the primary single-turn winding and the exciting coefficient of the secondary single-turn winding satisfy , and the set of exciting coefficients satisfies , where p i is the exciting coefficient of the i-th turn of the primary winding, s j is the exciting coefficient of the j-th turn of the secondary winding, n p is the number of turns of the primary winding, n s is the number of turns of the secondary winding, P is the set of exciting coefficients, p1~p np are the exciting coefficients corresponding to each primary winding, and s1~s ns are the exciting coefficients corresponding to each secondary winding.

[0017] Optionally, perform a full permutation on the (n p +n s ) exciting coefficients in the set of exciting coefficients to obtain non-repeated permutation sequences, and the coefficient matrix satisfies , where is the coefficient matrix, are the respective permutation sequences, n p is the number of turns of the primary winding, and n s is the number of turns of the secondary winding.

[0018] Optionally, the method for obtaining the stage summation matrix includes:

[0019] Design an upper triangular matrix based on the coefficient matrix, and perform stage summation operation on the coefficient matrix based on the upper triangular matrix to obtain a primary stage matrix;

[0020] Remove the last column in the primary stage matrix to obtain the stage summation matrix.

[0021] Optionally, the upper triangular matrix satisfies , and the primary stage matrix satisfies , where is the primary stage matrix, is the coefficient matrix, is the upper triangular matrix.

[0022] Optionally, the method for obtaining the first matrix includes: obtaining the maximum value of the absolute values of the elements in each row of the stage summation matrix, and forming the first matrix with these values; where the first matrix satisfies , is the first matrix, is the maximum value of the absolute values of the elements in each row of the stage summation matrix, is the k-th column of each row in the stage summation matrix, n p is the number of turns of the primary side winding, n s is the number of turns of the secondary side winding.

[0023] Optionally, the method for obtaining the second matrix includes: obtaining the sum of the absolute values of the elements in each row of the stage summation matrix, and forming the second matrix with these values; where the second matrix satisfies , is the second matrix, is the sum of the absolute values of the elements in each row of the stage summation matrix, is the k-th column of each row in the stage summation matrix, n p is the number of turns of the primary side winding, n s is the number of turns of the secondary side winding.

[0024] Optionally, the method for obtaining the optimal stacking method of the transformer winding includes: using the row number corresponding to the minimum value of the elements in the first matrix and / or the second matrix as the target row number, selecting the permutation sequence located at the target row number from the coefficient matrix, and using the corresponding stacking method as the optimal stacking method.

[0025] The present invention also provides a PCB transformer, which includes a transformer winding. Among them, the primary side winding and the secondary side winding in the transformer winding are arranged according to the optimal stacking method obtained by any one of the above design methods.

[0026] The present invention also provides a power supply module, and the power supply module includes the PCB transformer as described above.

[0027] As described above, the design method of the transformer winding, the PCB transformer and the power supply module of the present invention propose a general design method for the optimal stacking method of the winding through full permutation matrix operation and mathematical modeling, which not only solves the blindness and inefficiency of the traditional design relying on experience and simulation feedback, but also can effectively reduce the transformer loss and minimize the transformer loss; the winding arranged based on the optimal stacking method has a balanced magnetic field distribution, and the balanced magnetic field distribution and extremely low loss can reduce local hot spots and reduce the thermal coupling effect between the transformer and the winding, significantly improving the thermal stability and reliability of the power supply module. The design method of the present invention is applicable to various PCB transformers (especially multi-winding complex structures with any turn ratio), has high design flexibility, and can be extended to fields such as new energy and electric vehicles; the design method of the present invention can achieve performance improvement only by optimizing the winding stacking method, without additional materials or process improvements, and the cost increases almost zero, having extremely high cost effectiveness. Description of the Drawings

[0028] Figure 1 It shows a flowchart of the design method in the embodiment of the present invention.

[0029] Figure 2 It shows a schematic diagram of the stacking method corresponding to the arrangement sequence of the first row in the coefficient matrix of the transformer winding with a turn ratio of 3:2.

[0030] Figure 3 It shows a schematic diagram of the stacking method corresponding to the arrangement sequence of the second row in the coefficient matrix of the transformer winding with a turn ratio of 3:2.

[0031] Figure 4 It shows a schematic diagram of the stacking method corresponding to the arrangement sequence of the third row in the coefficient matrix of the transformer winding with a turn ratio of 3:2.

[0032] Figure 5 It shows a schematic diagram of the stacking method corresponding to the arrangement sequence of the fourth row in the coefficient matrix of the transformer winding with a turn ratio of 3:2.

[0033] Figure 6 It shows a schematic diagram of the stacking method corresponding to the arrangement sequence of the fifth row in the coefficient matrix of the transformer winding with a turn ratio of 3:2.

[0034] Figure 7 It shows a schematic diagram of the loss of the transformer composed of Figures 2 to 6 each of the transformer windings shown.

[0035] Figure 8 It shows a schematic diagram of the loss of the transformer composed of Figures 2 to 6Schematic diagram of the variation curves of the magnetic field intensity and leakage inductance of the transformer formed by the shown transformer windings. Specific implementation mode

[0036] The following uses specific specific examples to illustrate the implementation mode of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0037] Please refer to Figures 1 to 8 . It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The form, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout form may also be more complex.

[0038] As Figure 1 shown, this embodiment provides a design method for a transformer winding, including the following steps, for example, step S1 to step S4.

[0039] Step S1, based on the turns ratio of the transformer winding, determine the set of excitation coefficients of the transformer winding.

[0040] In one implementation mode, the method for determining the set of excitation coefficients includes: based on the turns ratio of the transformer winding, obtain the excitation coefficient of the primary single-turn winding and the excitation coefficient of the secondary single-turn winding of the transformer winding, and construct the set of excitation coefficients therefrom; wherein, the set of excitation coefficients includes the excitation coefficients corresponding to each primary winding and the excitation coefficients corresponding to each secondary winding, a total of excitation coefficients, n p is the number of turns of the primary winding, and n s is the number of turns of the secondary winding. It should be noted that the turns ratio of the transformer winding is one of the design specifications of the PCB transformer and is determined by the actual application scenario and belongs to known parameters.

[0041] In an example, the excitation coefficient of the primary single-turn winding satisfies , and, , where p i is the excitation coefficient of the i-th turn of the primary winding, and n s is the number of turns of the secondary winding; the excitation coefficient of the secondary single-turn winding satisfies , and, , where s j is the excitation coefficient of the j-th turn of the secondary winding, and n pis the number of turns of the primary winding; the set of excitation coefficients satisfies , where P is the set of excitation coefficients, p1 to p np are the excitation coefficients corresponding to each primary winding, and s1 to s ns are the excitation coefficients corresponding to each secondary winding.

[0042] Taking the turns ratio of the transformer winding as 3:2 as an example, that is, n p = 3, n s = 2. At this time, the values of i are 1, 2, and 3 respectively, and the values of j are 1 and 2 respectively. Then, p1 = p2 = p3 = 2, s1 = s2 = -3, and P = {p1, p2, p3, s1, s2}.

[0043] Step S2, perform a full permutation on each excitation coefficient in the set of excitation coefficients to obtain a number of non-repeated permutation sequences and form a coefficient matrix to represent all possible arrangement combinations of the transformer windings.

[0044] In this step, perform a full permutation on the excitation coefficients in the set of excitation coefficients to obtain non-repeated permutation sequences, where n p is the number of turns of the primary winding, and n s is the number of turns of the secondary winding. In an example, the coefficient matrix satisfies , where is the coefficient matrix, and this coefficient matrix includes rows columns, is each permutation sequence, and T is the transpose of the matrix.

[0045] Taking the set of excitation coefficients P = {p1, p2, p3, s1, s2} as an example, perform a full permutation on the five excitation coefficients to obtain ten non-repeated permutation sequences, where the ten non-repeated permutation sequences are (2 2 2 -3 -3), (2 2 -3 2 -3), (2 2 -3 -3 2), (2 -3 2 2 -3), (2 -3 2 -3 2), (2 -3 -3 2 2), (-3 2 2 2 -3), (-3 2 2 -3 2), (-3 2 -3 2 2), and (-3 -3 2 2 2); at this time, the coefficient matrix .

[0046] Step S3, perform a stage summation operation on the coefficient matrix to obtain a stage summation matrix. In one implementation, the method for obtaining the stage summation matrix includes the following steps, for example, Step S31 and Step S32.

[0047] Step S31: Design an upper triangular matrix based on the coefficient matrix, and perform a stage summation operation on the coefficient matrix based on the upper triangular matrix to obtain a primary stage matrix.

[0048] In one example, when designing the upper triangular matrix based on the coefficient matrix, the number of rows and columns of the upper triangular matrix is equal to the number of columns of the coefficient matrix; among them, the upper triangular matrix satisfies , is the upper triangular matrix, and this upper triangular matrix includes rows columns.

[0049] Complete the stage summation operation on the coefficient matrix by multiplying the coefficient matrix by the upper triangular matrix to obtain a primary stage matrix; among them, the primary stage matrix satisfies , is the primary stage matrix, and this primary stage matrix includes rows columns.

[0050] Taking the coefficient matrix as an example, then the upper triangular matrix , at this time, the primary stage matrix .

[0051] Step S32: Remove the last column in the primary stage matrix to obtain a stage summation matrix.

[0052] Taking the primary stage matrix as an example, then the stage summation matrix .

[0053] Step S4: Obtain a first matrix and / or a second matrix based on the stage summation matrix, and thereby obtain the optimal stacking method of the transformer winding.

[0054] In different application scenarios, different designs are made for the turns ratio of the transformer winding, that is, different designs are made for the number of turns of the primary winding and the number of turns of the secondary winding. For example, it can be designed that the number of turns of the primary winding is not equal to the number of turns of the secondary winding, that is, , of course, it can also be designed that the number of turns of the primary winding is equal to the number of turns of the secondary winding, that is, ; however, whether the number of turns of the primary winding is not equal to the number of turns of the secondary winding or the number of turns of the primary winding is equal to the number of turns of the secondary winding, at least one of the first matrix and the second matrix can be obtained based on the stage summation matrix, and thereby the optimal stacking method of the transformer winding can be obtained. It should be noted that for the case where the number of turns of the primary winding is equal to the number of turns of the secondary winding, it usually means , because the stacking method of the corresponding transformer winding is fixed, and there is no so-called optimal stacking method.

[0055] In one embodiment, when obtaining the first matrix based on the stage summation matrix, the specific method includes: obtaining the maximum value of the absolute values of the elements in each row of the stage summation matrix, and forming the first matrix therefrom; wherein, the first matrix satisfies , is the first matrix, is the maximum value of the absolute values of the elements in each row of the stage summation matrix, is the k-th column of each row in the stage summation matrix, n p is the number of turns of the primary winding, n s is the number of turns of the secondary winding.

[0056] Taking the stage summation matrix as an example, then, the first matrix .

[0057] When obtaining the second matrix based on the stage summation matrix, the specific method includes: obtaining the sum of the absolute values of the elements in each row of the stage summation matrix, and forming the second matrix therefrom; wherein, the second matrix satisfies , is the second matrix, is the sum of the absolute values of the elements in each row of the stage summation matrix, is the k-th column of each row in the stage summation matrix, n p is the number of turns of the primary winding, n s is the number of turns of the secondary winding.

[0058] Taking the stage summation matrix as an example, then, the second matrix .

[0059] In one embodiment, when obtaining the optimal stacking method of the transformer winding based on the first matrix and / or the second matrix, the specific method includes: taking the row number corresponding to the minimum value of the elements in the first matrix and / or the second matrix as the target row number, selecting the permutation sequence located at the target row number from the coefficient matrix, and taking the corresponding stacking method as the optimal stacking method.

[0060] When obtaining the optimal stacking method of the transformer winding based on the first matrix, taking the first matrix as an example, the value of the element in the 5th row is the smallest, so the 5th row is taken as the target row number; the permutation sequence (2 - 3 2 -3 2) located in the 5th row is selected from the coefficient matrix, and the corresponding stacking method is taken as the optimal stacking method to guide the design of the transformer winding. Among them, the stacking method corresponding to the transformer winding is, from bottom to top in turn: primary winding - secondary winding - primary winding - secondary winding - primary winding.

[0061] When obtaining the optimal stacking method of the transformer winding based on the second matrix, taking the second matrix For example, the value of the element in the 5th row is the smallest, so the 5th row is taken as the target row number; the permutation sequence (2 -3 2 -3 2) located in the 5th row is selected from the coefficient matrix, and its corresponding stacking method is taken as the optimal stacking method to guide the design of the transformer winding. Among them, the stacking method corresponding to the transformer winding is, from bottom to top in turn: primary winding - secondary winding - primary winding - secondary winding - primary winding.

[0062] When obtaining the optimal stacking method of the transformer winding based on the first matrix and the second matrix together, the 5th row is also taken as the target row number, and the permutation sequence (2 -3 2 -3 2) located in the 5th row is selected from the coefficient matrix, and its corresponding stacking method is taken as the optimal stacking method to guide the design of the transformer winding.

[0063] It can be seen that whether obtaining the optimal stacking method of the transformer winding based on the first matrix, or based on the second matrix, or even based on the first matrix and the second matrix together, the results are the same. In practical applications, since it is simpler and more convenient to obtain the first matrix, usually the first matrix is obtained based on the stage summation matrix, and the optimal stacking method of the transformer winding is obtained based on the first matrix. In addition, for the case where the number of turns of the primary winding is equal to the number of turns of the secondary winding, the obtained optimal stacking method may not be unique. At this time, any optimal stacking method can be selected according to the actual situation to guide the design.

[0064] Correspondingly, this embodiment also provides a PCB transformer, including a transformer winding. Among them, the primary winding and the secondary winding in the transformer winding are arranged according to the optimal stacking method obtained by the above design method; of course, the PCB transformer may also include other structures, such as a magnetic core, etc., which are not overly limited. The PCB transformer in this embodiment can minimize the transformer loss through the above winding stacking design.

[0065] Taking the coefficient matrix as an example, combining the above, the stacking method corresponding to the permutation sequence (2 -3 2 -3 2) in the 5th row is the optimal stacking method. Using the stacking methods corresponding to the 1st row to the 5th row to guide the design of the transformer windings as shown in Figures 2 to 6 , and performing simulation tests on the transformers composed of each transformer winding. The simulation test results are as shown in Figure 7 and Figure 8 ; from Figure 7 and Figure 8 , it can be seen that the transformer with the optimal stacking method has the smallest loss, the lowest magnetic field intensity, and the smallest leakage inductance.

[0066] Correspondingly, this embodiment also provides a power supply module, including a PCB transformer, wherein the PCB transformer is implemented by using the transformer structure described above. Of course, the power supply module may further include other structures, such as filters, controllers, etc., and no excessive restrictions are imposed thereon. In one implementation, the power supply module of this embodiment is a high-power density power supply module.

[0067] In summary, for a design method of a transformer winding, a PCB transformer and a power supply module of the present invention, through full permutation matrix operation and mathematical modeling, a general design method for the optimal winding stacking method is proposed, which not only solves the blindness and inefficiency problems of traditional design relying on experience and simulation feedback, but also can effectively reduce transformer losses and minimize transformer losses. The winding arranged based on the optimal stacking method has a balanced magnetic field distribution, and the balanced magnetic field distribution and extremely low losses can reduce local hot spots and reduce the thermal coupling effect between the transformer and the winding, significantly improving the thermal stability and reliability of the power supply module. The design method of the present invention is applicable to various PCB transformers (especially multi-winding complex structures with any turn ratio), has high design flexibility, and can be extended to fields such as new energy and electric vehicles. The design method of the present invention can achieve performance improvement only by optimizing the winding stacking method, without additional materials or process improvements, and the cost increases almost zero, having extremely high cost-effectiveness. Therefore, the present invention effectively overcomes various disadvantages in the prior art and has high industrial utilization value.

[0068] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A design method for a transformer winding, characterized in that, The design method includes: Determining an excitation coefficient set of the transformer winding based on the turns ratio of the transformer winding; Performing a full permutation on each excitation coefficient in the excitation coefficient set to obtain a number of non-repeating permutation sequences and forming a coefficient matrix; Performing a stage summation operation on the coefficient matrix to obtain a stage summation matrix; Obtaining a first matrix and / or a second matrix based on the stage summation matrix, and thereby obtaining an optimal stacking manner of the transformer winding; Among them, the method for obtaining the stage summation matrix includes: Designing an upper triangular matrix based on the coefficient matrix, and completing the stage summation operation on the coefficient matrix by multiplying the coefficient matrix by the upper triangular matrix to obtain a primary stage matrix; Removing the last column in the primary stage matrix to obtain the stage summation matrix.

2. The design method of the transformer winding according to claim 1, characterized in that, The method for determining the excitation coefficient set includes: obtaining the excitation coefficient of the primary single-turn winding and the excitation coefficient of the secondary single-turn winding in the transformer winding based on the turns ratio of the transformer winding, and constructing the excitation coefficient set therewith.

3. The design method of the transformer winding according to claim 2, wherein The excitation coefficient of the primary single-turn winding and the excitation coefficient of the secondary single-turn winding satisfy , and the set of excitation coefficients satisfies , where p i is the excitation coefficient of the i-th turn of the primary winding, and s j is the excitation coefficient of the j-th turn of the secondary winding, n p is the number of turns of the primary winding, and n s is the number of turns of the secondary winding. P is the set of excitation coefficients, and p1 to p np are the excitation coefficients corresponding to each primary winding, and s1 to s ns are the excitation coefficients corresponding to each secondary winding.

4. The design method of the transformer winding according to claim 1, wherein, Perform a full permutation on (n p + n s ) excitation coefficients in the set of excitation coefficients to obtain non-repeated permutation sequences, and the coefficient matrix satisfies , where is the coefficient matrix, is each permutation sequence, n p is the number of turns of the primary winding, and n s is the number of turns of the secondary winding.

5. The design method of the transformer winding according to claim 1, characterized in that, The upper triangular matrix satisfies , and the matrix in the primary stage satisfies , where is the matrix in the primary stage, is the coefficient matrix, is the upper triangular matrix, n p is the number of turns of the primary side winding, n s is the number of turns of the secondary side winding.

6. The design method of the transformer winding according to claim 1, characterized in that, The method for obtaining the first matrix includes: obtaining the maximum value of the absolute values of the elements in each row of the stage summation matrix, and forming the first matrix therewith; wherein, the first matrix satisfies , is the first matrix, is the maximum value of the absolute values of the elements in each row of the stage summation matrix, is the k-th column of each row in the stage summation matrix, n p is the number of turns of the primary side winding, n s is the number of turns of the secondary side winding.

7. The design method of the transformer winding according to claim 1, wherein, The method for obtaining the second matrix includes: obtaining the sum of the absolute values of the elements in each row of the stage summation matrix, and forming the second matrix therefrom; wherein, the second matrix satisfies , is the second matrix, is the sum of the absolute values of the elements in each row of the stage summation matrix, is the k-th column in each row of the stage summation matrix, n p is the number of turns of the primary side winding, n s is the number of turns of the secondary side winding.

8. The design method of the transformer winding according to claim 1, characterized in that The method for obtaining the optimal stacking manner of the transformer winding includes: taking the row number corresponding to the minimum value of the elements in the first matrix and / or the second matrix as the target row number, selecting the permutation sequence located at the target row number from the coefficient matrix, and taking the corresponding stacking manner as the optimal stacking manner.

9. A PCB transformer, characterized in that, The PCB transformer includes a transformer winding, wherein the primary winding and the secondary winding in the transformer winding are arranged in the optimal stacking manner obtained by the design method according to any one of claims 1 to 8.

10. A power module, characterized in that, The power supply module includes the PCB transformer according to claim 9.

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