A method for determining characteristics of a laminated core transformer and related apparatus

Abstract

A method for determining characteristics of a laminated core transformer and related device, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined based on an equivalent magnetic circuit model and magnetic induction under a direct current biasing condition. The equivalent magnetic circuit model is generated by equivalent correction of magnetic circuit parameters based on a direct current magnetic potential generated by a direct current component of a winding current when the laminated core transformer is in operation, the magnetic circuit parameters corresponding to an alternating current equivalent magnetic circuit model of a joint area of the laminated core transformer under a condition of no direct current biasing, the alternating current equivalent magnetic circuit model being generated based on a two-dimensional equivalent planar structure of the joint area, a magnetization curve and a core loss curve of a silicon steel sheet material. The equivalent magnetic circuit model can reflect a physical process in which the joint area preferentially enters a nonlinear magnetization region and a magnetic flux path is reconstructed under the action of the direct current biasing. Based on the equivalent magnetic circuit model, the influence of the direct current biasing on the magnetic characteristics and core loss of the laminated core transformer as a whole can be effectively reduced or avoided.

Description

Technical Field

[0001] This application relates to the field of power transformer technology, and in particular to a method and related apparatus for determining the characteristics of a laminated core transformer. Background Technology

[0002] Under ideal operating conditions, the magnetization process of a power transformer core is approximately symmetrical within the positive and negative half-cycles, and the magnetic flux distribution and magnetization state in each region of the core are relatively stable. However, with the grid connection of new energy sources, the widespread application of power electronic devices, and the integration of DC transmission systems, power transformers are inevitably affected by the DC component during operation, resulting in DC bias magnetization.

[0003] Under DC bias, due to the higher magnetic reluctance, reduced effective flux area, and flux concentration effect in the joint region of the laminated core transformer, the magnetic induction intensity in the joint region is higher than that in the main core region, and it will preferentially enter a saturation state. Once local saturation occurs in the joint region, its equivalent permeability will decrease rapidly, and the magnetic reluctance will increase significantly. This will then cause the flux path to be reconstructed inside the core, exerting a dominant influence on the overall magnetic characteristics and core losses of the laminated core transformer. Summary of the Invention

[0004] This application provides a method and related apparatus for determining the characteristics of laminated core transformers, aiming to reduce or avoid the influence of DC bias on the overall magnetic characteristics and core losses of laminated core transformers, and improve the accuracy of determining the characteristics of laminated core transformers.

[0005] First aspect: This application provides a method for determining the characteristics of a laminated core transformer, including: obtaining the magnetic induction intensity corresponding to the laminated core transformer; Based on the equivalent magnetic circuit model under DC bias and the magnetic induction intensity, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined. The equivalent magnetic circuit model under DC bias is generated by equivalent correction of the magnetic circuit parameters based on the DC magnetomotive force generated by the DC component of the winding current during operation of the laminated core transformer. The magnetic circuit parameters correspond to the AC equivalent magnetic circuit model of the joint area of ​​the laminated core transformer under no DC bias. The AC equivalent magnetic circuit model is generated based on the two-dimensional equivalent planar structure of the joint area, the magnetization curve and iron loss curve of the silicon steel sheet material used in the core of the laminated core transformer.

[0006] In one possible implementation, determining the magnetic characteristics and / or loss characteristics of the laminated core transformer based on the equivalent magnetic circuit model under DC bias conditions and the magnetic induction intensity includes: Based on the equivalent magnetic circuit model under the DC biased magnetic condition and the magnetic induction intensity, the variation characteristics of the equivalent magnetic reluctance of the joint region under the DC biased magnetic condition are determined. Based on the variation characteristics of the equivalent magnetoresistance of the joint area under DC bias, the critical magnetic induction intensity of the joint area under DC bias is determined. Based on the critical magnetic induction intensity of the joint region under the DC biased magnetic condition, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined.

[0007] In one possible implementation, determining the magnetic characteristics and / or loss characteristics of the laminated core transformer based on the critical magnetic induction intensity of the joint region under the DC bias condition includes: Based on the critical magnetic induction intensity of the joint region under the DC biased magnetic condition, a magnetic induction intensity sequence of the laminated iron core transformer under each magnetic circuit operating state is generated. Based on the magnetic induction intensity sequence, the equivalent permeability and equivalent iron loss of the joint region under DC bias conditions are determined. Based on the equivalent permeability and equivalent iron loss of the joint region under DC bias conditions, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined.

[0008] In one possible implementation, determining the magnetic characteristics and / or loss characteristics of the laminated core transformer based on the equivalent permeability and equivalent iron loss of the joint region under DC bias conditions includes: Based on the equivalent permeability and equivalent iron loss of the joint region under DC bias, the equivalent magnetization curve and equivalent loss curve of the joint region are generated. Based on the equivalent magnetization curve and equivalent loss curve of the joint region, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined.

[0009] In one possible implementation, the step of generating the AC equivalent magnetic circuit model includes: Based on the two-dimensional equivalent planar structure, for each lamination layer of the laminated core transformer, the magnetomotive force balance relationship and magnetic flux continuity condition corresponding to the lamination layer are determined. Based on the magnetic potential balance relationship and magnetic flux continuity condition, the joint region is equivalent to a single magnetic reluctance in the laminate layer to obtain the equivalent magnetic reluctance of the joint region in the laminate layer. Based on the structural parameters of the joint region, the equivalent permeability of the joint region under low magnetic induction intensity conditions is determined. Based on the air gap magnetoresistance, the equivalent permeability of the joint region when the working magnetic induction intensity exceeds the critical magnetic induction intensity is determined. Based on the equivalent magnetic reluctance of the joint region within the laminated layer, the equivalent magnetic permeability of the joint region under low magnetic induction intensity conditions, and the equivalent magnetic permeability of the joint region when the working magnetic induction intensity exceeds the critical magnetic induction intensity, the AC equivalent magnetic circuit model of the joint region under no DC bias magnetic conditions is generated.

[0010] In one possible implementation, the step of generating the equivalent magnetic circuit model under DC bias conditions includes: Based on the DC magnetomotive force generated by the DC component of the winding current during the operation of the laminated iron core transformer, the DC bias reluctance corresponding to the joint area and the differential permeability of the silicon steel sheet material at the DC operating point are determined. The sum of the equivalent magnetic reluctance of the joint region within the laminated layer and the DC bias magnetic reluctance is determined as the equivalent magnetic reluctance of the joint region under DC bias conditions. Based on the equivalent permeability of the joint area under low magnetic induction intensity conditions, the equivalent permeability of the joint area when the working magnetic induction intensity exceeds the critical magnetic induction intensity, and the differential permeability of the silicon steel sheet material at the DC operating point, the equivalent permeability of the joint area under the DC biased magnetization conditions is determined. Based on the equivalent reluctance and equivalent permeability of the joint region under DC bias conditions, an equivalent magnetic circuit model under DC bias conditions is generated.

[0011] In one possible implementation, the steps for generating the two-dimensional equivalent planar structure include: The three-dimensional structure of the joint region of the laminated iron core transformer is projected along the main magnetic flux direction to generate a two-dimensional equivalent planar structure of the joint region.

[0012] Second aspect: This application provides a characteristic determination device for laminated core transformers, including: an acquisition unit and a determination unit; The acquisition unit is used to acquire the magnetic induction intensity corresponding to the laminated iron core transformer; The determining unit is used to determine the magnetic characteristics and / or loss characteristics of the laminated core transformer based on the equivalent magnetic circuit model under DC bias conditions and the magnetic induction intensity. The equivalent magnetic circuit model under DC bias conditions is generated by equivalent correction of the magnetic circuit parameters based on the DC magnetomotive force generated by the DC component of the winding current during operation of the laminated core transformer. The magnetic circuit parameters correspond to the AC equivalent magnetic circuit model of the joint area of ​​the laminated core transformer under no DC bias conditions. The AC equivalent magnetic circuit model is generated based on the two-dimensional equivalent planar structure of the joint area, the magnetization curve and iron loss curve of the silicon steel sheet material used in the core of the laminated core transformer.

[0013] Third aspect: This application provides a computer device, which includes a processor and a memory; The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the steps of a method for determining the characteristics of a laminated core transformer as described above, according to the instructions in the program code.

[0014] Fourth aspect: This application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of a method for determining the characteristics of a laminated core transformer as described above.

[0015] Fifth aspect: This application provides a computer program product. When the computer program product is run on a computer, the computer executes the steps of a method for determining the characteristics of a laminated core transformer as described above.

[0016] Sixth aspect: This application provides a chip including a processor coupled to a memory for executing computer programs or instructions stored in the memory, so that the chip implements a method for determining the characteristics of a laminated core transformer as described above.

[0017] Compared with the prior art, the embodiments of this application have the following beneficial effects: This application provides a method and related apparatus for determining the characteristics of a laminated core transformer. The method involves obtaining the magnetic flux density corresponding to the laminated core transformer and determining its magnetic characteristics and / or loss characteristics based on an equivalent magnetic circuit model under DC bias conditions and the magnetic flux density. The equivalent magnetic circuit model under DC bias conditions is generated by equivalently correcting the magnetic circuit parameters based on the DC magnetomotive force generated by the DC component of the winding current during operation of the laminated core transformer. These magnetic circuit parameters correspond to the AC equivalent magnetic circuit model of the joint region of the laminated core transformer under conditions without DC bias. The AC equivalent magnetic circuit model is generated based on the two-dimensional equivalent planar structure of the joint region, the magnetization curve of the silicon steel sheet material used in the core of the laminated core transformer, and the iron loss curve. In generating the equivalent magnetic circuit model under DC bias conditions, this application considers the impact of the joint region on the overall magnetic characteristics and core losses of the laminated core transformer. It describes the influence of DC bias on the magnetic characteristics of the joint region from the perspective of magnetic circuit structure. The generated equivalent magnetic circuit model reflects the physical process of the joint region preferentially entering the nonlinear magnetization region and the magnetic flux path reconstruction under DC bias. Based on this, and using the equivalent magnetic circuit model and magnetic induction intensity under DC bias conditions, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined. This effectively reduces or avoids the impact of DC bias on the overall magnetic characteristics and core losses of the laminated core transformer, improving the accuracy of the determined characteristics. Attached Figure Description

[0018] Figure 1 A flowchart illustrating a method for determining the characteristics of a laminated core transformer provided in this application embodiment; Figure 2 A flowchart illustrating a method for determining the characteristics of a laminated core transformer provided in this application embodiment; Figure 3 A schematic diagram of a BH curve provided for an embodiment of this application; Figure 4 A schematic diagram of a BP curve provided for an embodiment of this application; Figure 5 This is a schematic diagram of a three-dimensional tower-connected layer structure provided in an embodiment of this application; Figure 6 A schematic diagram of a two-dimensional magnetic flux passing through a plane, provided for an embodiment of this application; Figure 7 A schematic diagram of an AC equivalent magnetic circuit model under conditions of no DC bias provided in this application embodiment; Figure 8 An equivalent BH curve of a joint area under DC bias magnetic conditions is provided for an embodiment of this application; Figure 9An equivalent BP curve of a joint area under DC bias magnetic conditions is provided for an embodiment of this application; Figure 10 A schematic diagram of a characteristic determination device for a laminated core transformer provided in an embodiment of this application; Figure 11 This is a schematic diagram of the hardware structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The terminology used in the following embodiments is for the purpose of describing specific embodiments only and is not intended to be a limitation of this application. As used in the specification and appended claims of this application, the singular expressions "a," "an," "the," "the," "the," and "this" are intended to also include expressions such as "one or more," unless the context clearly indicates otherwise. It should also be understood that in the embodiments of this application, "one or more" refers to one, two, or more; "and / or" describes the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0020] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0021] The "multiple" mentioned in the embodiments of this application refers to two or more. It should be noted that in the description of the embodiments of this application, terms such as "first" and "second" are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implying order.

[0022] As mentioned above, during operation, the core of a power transformer is typically in a periodic magnetization state dominated by alternating current (AC) flux. Under ideal conditions, the core magnetization process is approximately symmetrical within the positive and negative half-cycles, and the flux distribution and magnetization state in different regions of the core are relatively stable. However, with the grid connection of new energy sources, the widespread application of power electronic devices, and the integration of DC transmission systems, power transformers are inevitably affected by the DC component during operation, resulting in DC bias magnetization.

[0023] DC bias can be introduced through winding current, and the resulting DC magnetomotive force acts on the overall magnetic circuit of the power transformer, causing the operating point of the transformer core to shift from the original AC magnetization. Because the magnetization characteristics of the core material are significantly nonlinear, DC bias can cause local areas of the core to prematurely enter the nonlinear magnetization region or even the saturation region, leading to decreased permeability, increased magnetic reluctance, and abnormal magnetic flux distribution. This, in turn, results in a significant increase in core losses, noise, and vibration.

[0024] Laminated core transformers, a type of power transformer, use silicon steel sheets as the core material. The core is constructed by laminating the silicon steel sheets into a laminated structure. For example, in the core structure of a laminated core transformer, the core column and yoke body can be formed by laminating grain-oriented electrical steel along the rolling direction, which has the characteristics of high permeability and relatively uniform magnetization.

[0025] Because the core of a laminated core transformer is constructed by laminating silicon steel sheets into a laminated structure, there are seam areas between the silicon steel sheet layers. Due to the overlapping of the laminations, the presence of air gaps and insulation layers in the seam areas, and the deflection of magnetic flux when passing through the seam areas, the equivalent magnetic reluctance of the seam areas is significantly higher than that of other areas in the core.

[0026] Without DC bias, due to factors such as abrupt changes in reluctance and flux concentration, the magnetization operating point in the joint region is closer to the nonlinear region of the material's magnetization curve than that in the main body region of the core column. Under DC bias, although the DC magnetomotive force acts on the entire magnetic circuit, the joint region has higher reluctance and a smaller effective flux area. Furthermore, due to the flux concentration effect, the magnetic induction intensity in the joint region is higher than that in the main body region of the core column, and it will preferentially enter the saturation state.

[0027] Once local saturation occurs in the joint area, its equivalent permeability will drop rapidly and its magnetic reluctance will increase significantly, which will lead to the reconstruction of the magnetic flux path inside the core and have a dominant impact on the overall magnetic characteristics and core loss of the laminated core transformer.

[0028] Based on this, embodiments of this application provide a method and related apparatus for determining the characteristics of a laminated core transformer. The method involves obtaining the magnetic flux density corresponding to the laminated core transformer; and determining the magnetic characteristics and / or loss characteristics of the laminated core transformer based on an equivalent magnetic circuit model under DC bias conditions and the magnetic flux density. Specifically, the equivalent magnetic circuit model under DC bias conditions is generated by equivalently correcting the magnetic circuit parameters based on the DC magnetomotive force generated by the DC component of the winding current during operation of the laminated core transformer. These magnetic circuit parameters correspond to the AC equivalent magnetic circuit model of the joint region of the laminated core transformer under conditions without DC bias. The AC equivalent magnetic circuit model is generated based on the two-dimensional equivalent planar structure of the joint region, the magnetization curve of the silicon steel sheet material used in the core of the laminated core transformer, and the iron loss curve.

[0029] In generating the equivalent magnetic circuit model under DC bias conditions, this application considers the impact of the joint region on the overall magnetic characteristics and core losses of the laminated core transformer. It describes the influence of DC bias on the magnetic characteristics of the joint region from the perspective of magnetic circuit structure. The generated equivalent magnetic circuit model reflects the physical process of the joint region preferentially entering the nonlinear magnetization region and the magnetic flux path reconstruction under DC bias. Based on this, and using the equivalent magnetic circuit model and magnetic induction intensity under DC bias conditions, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined. This effectively reduces or avoids the impact of DC bias on the overall magnetic characteristics and core losses of the laminated core transformer, improving the accuracy of the determined characteristics.

[0030] The following, with reference to the accompanying drawings, describes a method for determining the characteristics of a laminated core transformer provided in an embodiment of this application. For example... Figure 1 As shown in the figure, this figure is a flowchart of a method for determining the characteristics of a laminated core transformer provided in an embodiment of this application, including S101-S102.

[0031] S101. Obtain the magnetic induction intensity corresponding to the laminated iron core transformer.

[0032] S102. Based on the equivalent magnetic circuit model under DC bias conditions and the magnetic induction intensity, determine the magnetic characteristics and / or loss characteristics of the laminated core transformer.

[0033] In this embodiment, the equivalent magnetic circuit model under DC bias is generated by equivalent correction of the magnetic circuit parameters based on the DC magnetomotive force generated by the DC component of the winding current during the operation of the laminated core transformer. The magnetic circuit parameters correspond to the AC equivalent magnetic circuit model of the joint area of ​​the laminated core transformer under no DC bias. The AC equivalent magnetic circuit model is generated based on the two-dimensional equivalent planar structure of the joint area, the magnetization curve and iron loss curve of the silicon steel sheet material used in the core of the laminated core transformer.

[0034] The two-dimensional equivalent planar structure of the joint area can be generated by projecting the three-dimensional structure of the joint area of ​​the laminated iron core transformer along the main magnetic flux direction.

[0035] In one possible implementation, before projecting the three-dimensional structure of the joint region of the laminated core transformer along the main magnetic flux direction, the joint region of the laminated core transformer can be identified to determine its three-dimensional structure and corresponding geometric parameters.

[0036] For example, the three-dimensional structure of the joint area of ​​a laminated core transformer can be a three-dimensional tower joint structure. The geometric parameters corresponding to this structure include, but are not limited to, the number of steps, the overlap length, the air gap position, and the distribution of the insulation layer.

[0037] Based on this, by projecting the three-dimensional structure of the joint area of ​​the laminated iron core transformer along the main direction of magnetic flux, a two-dimensional equivalent planar structure of the joint area can be generated. This two-dimensional equivalent planar structure can be used to divide the magnetic flux propagation path within the joint area.

[0038] In one possible implementation, during the process of generating an AC equivalent magnetic circuit model of the joint region under no DC bias magnetic conditions, based on the two-dimensional equivalent planar structure, the magnetization curve and iron loss curve of the silicon steel sheet material used in the laminated core transformer core, the magnetomotive force balance relationship and magnetic flux continuity condition corresponding to each lamination layer of the laminated core transformer can be determined based on the two-dimensional equivalent planar structure. Based on the magnetomotive force balance relationship and magnetic flux continuity condition, the joint region is equivalent to a single magnetic reluctance within the lamination layer, thus obtaining the equivalent magnetic reluctance of the joint region within the lamination layer. Based on the structural parameters of the joint region, the equivalent permeability of the joint region under low magnetic induction intensity conditions is determined. Based on the air gap magnetic reluctance, the equivalent permeability of the joint region when the working magnetic induction intensity exceeds the critical magnetic induction intensity is determined.

[0039] Based on this, an AC equivalent magnetic circuit model of the joint region under no DC bias is generated, based on the equivalent magnetic reluctance of the joint region in the laminated layer, the equivalent magnetic permeability of the joint region under low magnetic induction intensity conditions, and the equivalent magnetic permeability of the joint region when the working magnetic induction intensity exceeds the critical magnetic induction intensity.

[0040] Among them, the magnetization (BH) curve and the iron loss (BP) curve are curves that describe the electromagnetic performance of laminated core transformers. The BH curve can be used to describe the relationship between the magnetic induction intensity (B) and the magnetic field intensity (H) in silicon steel sheets. It is an important parameter for evaluating the magnetization characteristics of silicon steel sheets and can reflect the magnetization ability of silicon steel sheets under different magnetic field intensities. The BP curve can be used to describe the relationship between the magnetic induction intensity (B) and the iron loss per unit mass (P) in silicon steel sheets. It is an important parameter for evaluating the energy loss characteristics of silicon steel sheets and can reflect the iron loss of silicon steel sheets under different magnetic induction intensities.

[0041] The AC equivalent magnetic circuit model of the seam area under no DC bias conditions may include, but is not limited to, the lap area magnetic reluctance, air gap magnetic reluctance, insulation magnetic reluctance, and on-chip magnetic reluctance.

[0042] In this embodiment, based on the AC equivalent magnetic circuit model without DC bias, the DC magnetomotive force generated by the DC component of the winding current during the operation of the laminated core transformer is considered. When the core magnetization point deviates by DC from the AC magnetization, the material in the joint area will gradually enter the nonlinear magnetization region or even the local saturation region, and its equivalent permeability will decrease accordingly.

[0043] The aforementioned changes in magnetization state manifest as an increase in magnetic reluctance in the joint region at the magnetic circuit level. Therefore, the change in permeability caused by DC bias is equivalently characterized as an additional magnetic reluctance component in the magnetic circuit. This additional magnetic reluctance, together with the original AC magnetic reluctance, constitutes the equivalent magnetic reluctance of the joint region under DC bias conditions, thereby establishing an equivalent magnetic circuit model under DC bias conditions (also known as a DC-AC composite magnetic circuit model).

[0044] In one possible implementation, the magnetic circuit parameters of the AC equivalent magnetic circuit model include, but are not limited to, the equivalent magnetoresistance of the joint region within the laminated layer, the equivalent permeability of the joint region under low magnetic induction intensity conditions, and the equivalent permeability of the joint region when the working magnetic induction intensity exceeds the critical magnetic induction intensity.

[0045] Based on the DC magnetomotive force generated by the DC component of the winding current during operation of the laminated core transformer, the magnetic circuit parameters of the AC equivalent magnetic circuit model under no DC bias are equivalently corrected. During the generation of the equivalent magnetic circuit model under DC bias, the DC bias reluctance corresponding to the joint region and the differential permeability of the silicon steel sheet material at the DC operating point can be determined based on the DC magnetomotive force generated by the DC component of the winding current during operation of the laminated core transformer. The sum of the equivalent reluctance of the joint region within the laminated layer and the DC bias reluctance is determined as the equivalent reluctance of the joint region under DC bias. Based on the equivalent permeability of the joint region under low magnetic flux density conditions, the equivalent permeability of the joint region when the operating magnetic flux density exceeds the critical magnetic flux density, and the differential permeability of the silicon steel sheet material at the DC operating point, the equivalent permeability of the joint region under DC bias conditions is determined.

[0046] After obtaining the equivalent magnetoresistance and equivalent permeability of the joint region under DC bias conditions, an equivalent magnetic circuit model under DC bias conditions is generated based on the equivalent magnetoresistance and equivalent permeability of the joint region under DC bias conditions.

[0047] In this embodiment, considering that the equivalent magnetic reluctance of the joint region exhibits a significant nonlinear change characteristic as the degree of DC bias increases, when the equivalent magnetic reluctance of the joint region increases to the point that the magnetopotential drop on the original overlapping path exceeds the magnetopotential drop on the air gap or other alternative magnetic flux paths, the magnetic flux distribution will change, and some magnetic flux will transfer to a new magnetic flux path. Using the magnetization state of the joint region corresponding to the occurrence of the aforementioned magnetic flux path reconstruction as the criterion, the magnetic induction intensity at this time is determined as the critical magnetic induction intensity of the joint region under DC bias conditions, which can distinguish the magnetic characteristics and loss characteristics under different magnetic circuit operating states.

[0048] Based on this, in the process of determining the magnetic characteristics and / or loss characteristics of the laminated core transformer based on the equivalent magnetic circuit model and magnetic induction intensity under the DC bias condition, this application embodiment determines the change characteristics of the equivalent magnetic reluctance of the joint region under the DC bias condition by using the equivalent magnetic circuit model and magnetic induction intensity under the DC bias condition; and determines the critical magnetic induction intensity of the joint region under the DC bias condition based on the change characteristics of the equivalent magnetic reluctance of the joint region under the DC bias condition.

[0049] Based on this, the magnetic characteristics and / or loss characteristics of the laminated core transformer under various magnetic circuit operating states can be determined based on the critical magnetic induction intensity of the joint region under the DC biased magnetic conditions.

[0050] For example, based on the critical magnetic flux density of the joint region under DC bias, a magnetic flux density sequence of the laminated core transformer under various magnetic circuit operating states can be generated. Based on the magnetic flux density sequence of the laminated core transformer under various magnetic circuit operating states, the equivalent permeability and equivalent iron loss of the joint region under DC bias are determined. Based on the equivalent permeability and equivalent iron loss of the joint region under DC bias, the magnetic characteristics and / or loss characteristics of the laminated core transformer under various magnetic circuit operating states are determined.

[0051] In determining the magnetic characteristics and / or loss characteristics of the laminated core transformer under DC bias conditions based on the equivalent permeability and equivalent iron loss of the joint region, equivalent magnetization curves and equivalent loss curves of the joint region can be generated based on the equivalent permeability and equivalent iron loss of the joint region under DC bias conditions. Based on the equivalent magnetization curves and equivalent loss curves of the joint region, the magnetic characteristics and / or loss characteristics of the laminated core transformer under various magnetic circuit operating conditions can be determined.

[0052] In summary, the embodiments of this application, in generating the equivalent magnetic circuit model under DC bias conditions, consider the impact of the joint region on the overall magnetic characteristics and core losses of the laminated core transformer under DC bias conditions. The influence of DC bias on the magnetic characteristics of the joint region is described at the magnetic circuit structure level. The generated equivalent magnetic circuit model can reflect the physical process of the joint region preferentially entering the nonlinear magnetization region and the magnetic flux path reconstruction under DC bias. Based on this, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined according to the equivalent magnetic circuit model and magnetic induction intensity under DC bias conditions. This effectively reduces or avoids the impact of DC bias on the overall magnetic characteristics and core losses of the laminated core transformer, improving the accuracy of the determined characteristics of the laminated core transformer.

[0053] To facilitate understanding, the following will be combined with Figures 2-9 The embodiments of this application will be described in general.

[0054] like Figure 2 As shown in the figure, this figure is a flowchart of a method for determining the characteristics of a laminated core transformer provided in an embodiment of this application.

[0055] S201. Obtain the BH curve and BP curve of the silicon steel sheet material used in the laminated core transformer.

[0056] In this embodiment, the laminated core transformer can be a five-stage step-laminated core transformer. The core of the five-stage step-laminated core transformer consists of five sets of overlapping layers, each set of overlapping layers being formed by overlapping several laminations. Each lamination includes an upper yoke, a lower yoke, and a core post, with both ends of the core post connected to the upper and lower yokes respectively using a specific connection method.

[0057] It is understood that the type of laminated core transformer is not specifically limited in the embodiments of this application, and only a five-stage step laminated core transformer is used as an example for introduction.

[0058] In this embodiment of the application, the BH curve and BP curve of the silicon steel sheet material used in the laminated core transformer can be obtained by measuring the silicon steel sheet material, or by calling the pre-measured BH curve and BP curve of the silicon steel sheet material in the database. Figure 3 and Figure 4 As shown, these are schematic diagrams of a BH curve and a BP curve provided in an embodiment of this application, respectively. It can be understood that... Figures 3-4 The BH and BP curves shown are for illustrative purposes only.

[0059] S202. Based on the BH curve, determine the equivalent permeability of the silicon steel sheet material under different magnetic induction intensities.

[0060] Figure 3 The diagram illustrates the relationship between the BH curve and the equivalent permeability of silicon steel sheet material under different magnetic induction intensities. The equivalent permeability (μ) of silicon steel sheet material under different magnetic induction intensities is shown in the diagram. r The following can be expressed by equation (1): (1) S203. Identify the overlapping form and corresponding geometric parameters of the joint area of ​​the laminated iron core transformer.

[0061] like Figure 5 As shown in the figure, this figure is a schematic diagram of a three-dimensional tower connection layer structure provided in an embodiment of this application.

[0062] In this embodiment of the application, the overlapping layer structure of the joint area is identified and the geometric parameters of the overlapping layer structure are extracted to obtain the overlapping form and geometric parameters of the joint area.

[0063] For example, geometric parameters include, but are not limited to, step number, overlap length, air gap location, and insulation layer distribution.

[0064] S204. Based on the overlap form and geometric parameters of the joint area, generate a two-dimensional magnetic flux passing plane for the tower layer structure of the joint area.

[0065] like Figure 6As shown, this figure is a schematic diagram of a two-dimensional magnetic flux transmission plane provided in an embodiment of this application. Exemplarily, in this embodiment, based on the overlap form and geometric parameters of the seam region, the three-dimensional interlocking layer structure of the seam region is projected along the main magnetic flux direction. This allows the interlocking layer structure to be equivalent to a two-dimensional magnetic flux transmission plane, thus obtaining the two-dimensional magnetic flux transmission plane of the interlocking layer structure. Based on this two-dimensional magnetic flux transmission plane, the magnetic flux propagation path within the seam region can be defined.

[0066] S205. Based on the two-dimensional magnetic flux passing through the plane, an AC equivalent magnetic circuit model is generated under the condition of no DC bias.

[0067] like Figure 7 As shown in the figure, this is a schematic diagram of an AC equivalent magnetic circuit model under conditions without DC bias, provided in an embodiment of this application. The AC equivalent magnetic circuit model under conditions without DC bias includes the overlap region reluctance, air gap reluctance, insulation reluctance, and on-chip reluctance.

[0068] The formulas for calculating each magnetic reluctance are as follows: (2) In equation (2), R represents magnetic reluctance, including but not limited to the reluctance of the overlap region, the air gap reluctance, the insulation reluctance, and the on-chip reluctance; μ0 is the air permeability; μ r The relative permeability (also known as the equivalent permeability) can be determined based on S201-S202; L is the path length of the magnetic flux; and S is the area of ​​the path through which the magnetic flux passes.

[0069] In one possible implementation, within the same laminate, the magnetic flux path satisfies Ampere's circuital law, and its magnetopotential balance relationship is as follows: (3) Where, Φ i R represents the magnetic flux through the i-th branch of the magnetic flux path; i Let represent the magnetic reluctance of the i-th magnetic flux branch path.

[0070] Meanwhile, each flux branch path satisfies the flux continuity condition as shown in equation (4): (4) Where, Φ L This represents the sum of magnetic flux in each magnetic flux branch path.

[0071] Based on the above magnetic potential balance relationship and magnetic flux continuity condition, the joint region within the laminate is equivalent to a single magnetic reluctance, and the equivalent magnetic reluctance of the joint region within the laminate is obtained, as expressed by equation (5) as follows: (5) Among them, R eL represents the equivalent magnetic reluctance of the seam region within the laminated layer. ge Indicates the equivalent length of the magnetic circuit in the joint region; μ re S represents the equivalent permeability of the seam region; L This represents the equivalent magnetic flux cross-sectional area of ​​the seam region.

[0072] Under low magnetic induction intensity conditions, the magnetic flux mainly travels around the air gap through the laminated insulation path, and its equivalent permeability is determined by the joint structure parameters, as shown in Equation (6): (6) When the working magnetic induction intensity increases to the critical state, the electrical steel in the joint area tends to saturate, and its critical magnetic induction intensity is expressed by equation (7) as follows: (7) Among them, B c B is the critical magnetic flux density. s It represents the saturation magnetic induction intensity.

[0073] When the operating magnetic flux density exceeds the critical magnetic flux density, the magnetic flux mainly passes through the air gap path, and its equivalent permeability is determined by the air gap reluctance, as expressed by equation (8): (8) Among them, R g This indicates the air gap magnetic reluctance.

[0074] S206. Based on the DC magnetomotive force generated by the DC component current in the winding current, the magnetic circuit parameters of the AC equivalent magnetic circuit model are corrected to obtain the equivalent magnetic circuit model under DC bias conditions.

[0075] The magnetic circuit parameters of the AC equivalent magnetic circuit model include, but are not limited to, the equivalent magnetic reluctance of the joint area in the laminate layer shown in Equations (2) to (8), the equivalent magnetic permeability under low magnetic induction intensity conditions, the critical magnetic induction intensity, and the equivalent magnetic permeability when the working magnetic induction intensity exceeds the critical magnetic induction intensity.

[0076] In this embodiment, based on the AC equivalent magnetic circuit model without DC bias, the DC magnetomotive force generated by the DC component of the winding current during the operation of the laminated core transformer is considered. When the core magnetization point deviates by DC from the AC magnetization, the material in the joint area will gradually enter the nonlinear magnetization region or even the local saturation region, and its equivalent permeability will decrease accordingly.

[0077] The aforementioned changes in magnetization state manifest as an increase in magnetic reluctance in the joint region at the magnetic circuit level. Therefore, the change in permeability caused by DC bias is equivalently characterized as an additional magnetic reluctance component in the magnetic circuit. This additional magnetic reluctance, together with the original AC magnetic reluctance, constitutes the equivalent magnetic reluctance of the joint region under DC bias conditions, thereby establishing an equivalent magnetic circuit model under DC bias conditions (also known as a DC-AC composite magnetic circuit model).

[0078] For example, the AC equivalent magnetoresistive (R) under conditions without DC bias magnetization. e Based on this, a DC bias reluctance (R) is introduced. dc The equivalent magnetic reluctance of the joint region under DC bias can be obtained, as expressed by equation (9) as follows: R e，dc =R e +R dc (9) Among them, R e，dc This represents the equivalent magnetoresistance of the joint area under DC bias conditions.

[0079] The degradation of permeability caused by DC bias can be measured by the differential permeability (μ) of the silicon steel sheet material at the DC operating point. dc The following is represented: (10) The equivalent permeability of the joint region under DC bias is expressed by equation (11) as follows: (11) Where, μ re，dc The equivalent permeability of the joint region under DC bias conditions.

[0080] Under DC bias, the equivalent magnetic flux density of the joint region is expressed by equation (12) as follows: B eq =B dc +B w (12) Among them, B eq B represents the equivalent magnetic flux density in the joint area under DC bias conditions. dc B represents the DC magnetic flux density. w This represents the magnetic flux density component associated with iron loss.

[0081] In this embodiment of the application, the unit iron loss can be calculated using the Bertotti iron loss model. Based on this, according to B w With B dc The relationship can distinguish the state of the magnetic flux path.

[0082] For example, as the degree of DC bias increases, the equivalent magnetic reluctance in the joint region exhibits a significant nonlinear change. When the equivalent magnetic reluctance in the joint region increases to the point that the magnetic potential drop on the original overlapping path exceeds the magnetic potential drop on the air gap or other alternative magnetic flux paths, the magnetic flux distribution will change, and some magnetic flux will be transferred to the new magnetic flux path.

[0083] Using the magnetization state of the joint area corresponding to the above-mentioned magnetic flux path reconstruction as the criterion, the magnetic induction intensity at this time is determined as the critical magnetic induction intensity of the joint area under DC bias conditions, which is used to distinguish the magnetic characteristics and loss characteristics under different magnetic circuit working conditions.

[0084] It is understood that, in the embodiments of this application, an equivalent magnetic circuit model under DC bias conditions can be generated in advance based on S201-S206. During the generation of the equivalent magnetic circuit model under DC bias conditions, the influence of the joint region on the overall magnetic characteristics and core loss of the laminated core transformer under DC bias conditions is considered. The influence of DC bias on the magnetic characteristics of the joint region is described from the perspective of magnetic circuit structure. The generated equivalent magnetic circuit model can reflect the physical process of the joint region preferentially entering the nonlinear magnetization region and the magnetic flux path reconstruction under the action of DC bias. After generating the equivalent magnetic circuit model under DC bias conditions, the equivalent magnetic characteristics and loss characteristics of the joint region can be directly determined based on this model, which can effectively improve the accuracy of the determined equivalent magnetic characteristics and loss characteristics.

[0085] S207. By establishing different magnetic induction intensity sequences, the equivalent permeability and equivalent iron loss of the joint region under DC bias conditions are determined.

[0086] In this embodiment, the equivalent magnetic flux density of the joint region under DC bias can distinguish the magnetic properties and loss characteristics under different magnetic circuit operating conditions. Based on this, a sequence of different magnetic flux densities is established. Under different DC bias conditions, the equivalent permeability of the joint region is determined based on the equivalent magnetic circuit model under that DC bias condition, and the equivalent iron loss of the joint region under DC bias conditions is determined by combining it with the material loss model.

[0087] S208. Based on the equivalent permeability and equivalent iron loss of the joint region, determine the equivalent magnetic characteristics and loss characteristics of the joint region.

[0088] In this embodiment, the equivalent permeability and equivalent iron loss of the joint region can be used as input parameters for the overall magnetic characteristic analysis and core loss assessment of the laminated core transformer. The performance of the laminated core transformer is then evaluated to obtain the assessment results. These results can be used to indicate the equivalent magnetic and loss characteristics of the joint region.

[0089] For example, in the embodiments of this application, based on the equivalent permeability and equivalent iron loss of the joint region, the equivalent BH curve and equivalent BP curve of the joint region under DC bias conditions can be obtained, such as... Figure 8 and Figure 9 As shown.

[0090] Using the equivalent BH curve and equivalent BP curve of the joint region under DC biased magnetization as input parameters for the overall magnetic characteristic analysis and core loss assessment of laminated core transformers, the equivalent magnetic characteristics and loss characteristics of the joint region can be determined by evaluating the performance of laminated core transformers.

[0091] In summary, the embodiments of this application, in generating the equivalent magnetic circuit model under DC bias conditions, consider the impact of the joint region on the overall magnetic characteristics and core losses of the laminated core transformer under DC bias conditions. The influence of DC bias on the magnetic characteristics of the joint region is described at the magnetic circuit structure level. The generated equivalent magnetic circuit model can reflect the physical process of the joint region preferentially entering the nonlinear magnetization region and the magnetic flux path reconstruction under DC bias. Based on this, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined according to the equivalent magnetic circuit model and magnetic induction intensity under DC bias conditions. This effectively reduces or avoids the impact of DC bias on the overall magnetic characteristics and core losses of the laminated core transformer, improving the accuracy of the determined characteristics of the laminated core transformer.

[0092] Meanwhile, the method provided in this application embodiment can reduce computational complexity while ensuring modeling accuracy, making it suitable for engineering design stage applications and improving the accuracy of core loss assessment for laminated core transformers under DC bias conditions.

[0093] This application provides a characteristic determination device for laminated core transformers, see [link to relevant documentation]. Figure 10 The figure is a schematic diagram of a characteristic determination device for a laminated iron core transformer provided in an embodiment of this application. Its specific implementation method is consistent with the implementation method and the technical effect achieved in the above-mentioned method embodiment, and some contents will not be repeated.

[0094] This application provides a characteristic determination device 1000 for laminated core transformers, comprising: Acquisition unit 1001 and determination unit 1002; The acquisition unit 1001 is used to acquire the magnetic induction intensity corresponding to the laminated iron core transformer. The determining unit 1002 is used to determine the magnetic characteristics and / or loss characteristics of the laminated core transformer based on the equivalent magnetic circuit model under DC bias conditions and the magnetic induction intensity. The equivalent magnetic circuit model under DC bias conditions is generated by equivalent correction of the magnetic circuit parameters based on the DC magnetomotive force generated by the DC component of the winding current during operation of the laminated core transformer. The magnetic circuit parameters correspond to the AC equivalent magnetic circuit model of the joint area of ​​the laminated core transformer under no DC bias conditions. The AC equivalent magnetic circuit model is generated based on the two-dimensional equivalent planar structure of the joint area, the magnetization curve and iron loss curve of the silicon steel sheet material used in the core of the laminated core transformer.

[0095] In one possible implementation, the determining unit is specifically used for: Based on the equivalent magnetic circuit model under the DC biased magnetic condition and the magnetic induction intensity, the variation characteristics of the equivalent magnetic reluctance of the joint region under the DC biased magnetic condition are determined. Based on the variation characteristics of the equivalent magnetoresistance of the joint area under DC bias, the critical magnetic induction intensity of the joint area under DC bias is determined. Based on the critical magnetic induction intensity of the joint region under the DC biased magnetic condition, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined.

[0096] In one possible implementation, the determining unit is specifically used for: Based on the critical magnetic induction intensity of the joint region under the DC biased magnetic condition, a magnetic induction intensity sequence of the laminated iron core transformer under each magnetic circuit operating state is generated. Based on the magnetic induction intensity sequence, the equivalent permeability and equivalent iron loss of the joint region under DC bias conditions are determined. Based on the equivalent permeability and equivalent iron loss of the joint region under DC bias conditions, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined.

[0097] In one possible implementation, the determining unit is specifically used for: Based on the equivalent permeability and equivalent iron loss of the joint region under DC bias, the equivalent magnetization curve and equivalent loss curve of the joint region are generated. Based on the equivalent magnetization curve and equivalent loss curve of the joint region, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined.

[0098] In one possible implementation, the apparatus further includes a generation unit; The generation unit is specifically used for: Based on the two-dimensional equivalent planar structure, for each lamination layer of the laminated core transformer, the magnetomotive force balance relationship and magnetic flux continuity condition corresponding to the lamination layer are determined. Based on the magnetic potential balance relationship and magnetic flux continuity condition, the joint region is equivalent to a single magnetic reluctance in the laminate layer to obtain the equivalent magnetic reluctance of the joint region in the laminate layer. Based on the structural parameters of the joint region, the equivalent permeability of the joint region under low magnetic induction intensity conditions is determined. Based on the air gap magnetoresistance, the equivalent permeability of the joint region when the working magnetic induction intensity exceeds the critical magnetic induction intensity is determined. Based on the equivalent magnetic reluctance of the joint region within the laminated layer, the equivalent magnetic permeability of the joint region under low magnetic induction intensity conditions, and the equivalent magnetic permeability of the joint region when the working magnetic induction intensity exceeds the critical magnetic induction intensity, the AC equivalent magnetic circuit model of the joint region under no DC bias magnetic conditions is generated.

[0099] In one possible implementation, the generating unit is specifically used for: Based on the DC magnetomotive force generated by the DC component of the winding current during the operation of the laminated iron core transformer, the DC bias reluctance corresponding to the joint area and the differential permeability of the silicon steel sheet material at the DC operating point are determined. The sum of the equivalent magnetic reluctance of the joint region within the laminated layer and the DC bias magnetic reluctance is determined as the equivalent magnetic reluctance of the joint region under DC bias conditions. Based on the equivalent permeability of the joint area under low magnetic induction intensity conditions, the equivalent permeability of the joint area when the working magnetic induction intensity exceeds the critical magnetic induction intensity, and the differential permeability of the silicon steel sheet material at the DC operating point, the equivalent permeability of the joint area under the DC biased magnetization conditions is determined. Based on the equivalent reluctance and equivalent permeability of the joint region under DC bias conditions, an equivalent magnetic circuit model under DC bias conditions is generated.

[0100] In one possible implementation, the generating unit is specifically used for: The three-dimensional structure of the joint region of the laminated iron core transformer is projected along the main magnetic flux direction to generate a two-dimensional equivalent planar structure of the joint region.

[0101] In summary, the embodiments of this application, in generating the equivalent magnetic circuit model under DC bias conditions, consider the impact of the joint region on the overall magnetic characteristics and core losses of the laminated core transformer under DC bias conditions. The influence of DC bias on the magnetic characteristics of the joint region is described at the magnetic circuit structure level. The generated equivalent magnetic circuit model can reflect the physical process of the joint region preferentially entering the nonlinear magnetization region and the magnetic flux path reconstruction under DC bias. Based on this, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined based on the equivalent magnetic circuit model and magnetic induction intensity under DC bias conditions. This effectively reduces or avoids the impact of DC bias on the overall magnetic characteristics and core losses of the laminated core transformer, improving the accuracy of the determined characteristics of the laminated core transformer.

[0102] Meanwhile, the device provided in this application embodiment can reduce computational complexity while ensuring modeling accuracy, making it suitable for engineering design stage applications and improving the accuracy of core loss assessment for laminated core transformers under DC bias conditions.

[0103] This application provides a computer device, such as... Figure 11 As shown in the figure, this figure is a schematic diagram of the hardware structure of a computer device provided in an embodiment of this application.

[0104] The computer device 1110 includes: a processor 1111 and a memory 1112; The memory 1112 is used to store program code and transmit the program code to the processor 1111; The processor 1111 is used to execute the steps of the method for determining the characteristics of a laminated core transformer as described above, according to the instructions in the program code.

[0105] For example, the processor 1111 acquires the magnetic flux density corresponding to the laminated core transformer; based on the equivalent magnetic circuit model under DC bias conditions and the magnetic flux density, it determines the magnetic characteristics and / or loss characteristics of the laminated core transformer; the equivalent magnetic circuit model under DC bias conditions is generated by equivalent correction of the magnetic circuit parameters based on the DC magnetomotive force generated by the DC component of the winding current during operation of the laminated core transformer, and the magnetic circuit parameters correspond to the AC equivalent magnetic circuit model of the joint area of ​​the laminated core transformer under no DC bias conditions, and the AC equivalent magnetic circuit model is generated based on the two-dimensional equivalent planar structure of the joint area, the magnetization curve and iron loss curve of the silicon steel sheet material used in the core of the laminated core transformer.

[0106] This application provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the steps of a method for determining the characteristics of a laminated core transformer as described above.

[0107] This application provides a computer program product. When the computer program product is run on a computer, the computer executes the steps of a method for determining the characteristics of a laminated core transformer as described above.

[0108] This application provides a chip including a processor coupled to a memory for executing computer programs or instructions stored in the memory, thereby enabling the chip to implement a method for determining the characteristics of a laminated core transformer as described above.

[0109] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for the device and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiments. The device and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components indicated as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the solution in this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0110] The above description is merely one specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for determining the characteristics of a laminated core transformer, characterized in that, include: Obtain the magnetic flux density corresponding to the laminated iron core transformer; Based on the equivalent magnetic circuit model under DC bias and the magnetic induction intensity, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined. The equivalent magnetic circuit model under DC bias is generated by equivalent correction of the magnetic circuit parameters based on the DC magnetomotive force generated by the DC component of the winding current during operation of the laminated core transformer. The magnetic circuit parameters correspond to the AC equivalent magnetic circuit model of the joint area of ​​the laminated core transformer under no DC bias. The AC equivalent magnetic circuit model is generated based on the two-dimensional equivalent planar structure of the joint area, the magnetization curve and iron loss curve of the silicon steel sheet material used in the core of the laminated core transformer.

2. The method according to claim 1, characterized in that, The magnetic characteristics and / or loss characteristics of the laminated core transformer are determined based on the equivalent magnetic circuit model under DC bias conditions and the magnetic induction intensity, including: Based on the equivalent magnetic circuit model under the DC biased magnetic condition and the magnetic induction intensity, the variation characteristics of the equivalent magnetic reluctance of the joint region under the DC biased magnetic condition are determined. Based on the variation characteristics of the equivalent magnetoresistance of the joint area under DC bias, the critical magnetic induction intensity of the joint area under DC bias is determined. Based on the critical magnetic induction intensity of the joint region under the DC biased magnetic condition, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined.

3. The method according to claim 2, characterized in that, The determination of the magnetic characteristics and / or loss characteristics of the laminated core transformer based on the critical magnetic induction intensity of the joint region under the DC bias condition includes: Based on the critical magnetic induction intensity of the joint region under the DC biased magnetic condition, a magnetic induction intensity sequence of the laminated iron core transformer under each magnetic circuit operating state is generated. Based on the magnetic induction intensity sequence, the equivalent permeability and equivalent iron loss of the joint region under DC bias conditions are determined. Based on the equivalent permeability and equivalent iron loss of the joint region under DC bias conditions, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined.

4. The method according to claim 3, characterized in that, The determination of the magnetic characteristics and / or loss characteristics of the laminated core transformer based on the equivalent permeability and equivalent iron loss of the joint region under DC bias conditions includes: Based on the equivalent permeability and equivalent iron loss of the joint region under DC bias, the equivalent magnetization curve and equivalent loss curve of the joint region are generated. Based on the equivalent magnetization curve and equivalent loss curve of the joint region, the magnetic characteristics and / or loss characteristics of the laminated core transformer are determined.

5. The method according to claim 1, characterized in that, The steps for generating the AC equivalent magnetic circuit model include: Based on the two-dimensional equivalent planar structure, for each lamination layer of the laminated core transformer, the magnetomotive force balance relationship and magnetic flux continuity condition corresponding to the lamination layer are determined. Based on the magnetic potential balance relationship and magnetic flux continuity condition, the joint region is equivalent to a single magnetic reluctance in the laminate layer to obtain the equivalent magnetic reluctance of the joint region in the laminate layer. Based on the structural parameters of the joint region, the equivalent permeability of the joint region under low magnetic induction intensity conditions is determined. Based on the air gap magnetoresistance, the equivalent permeability of the joint region when the working magnetic induction intensity exceeds the critical magnetic induction intensity is determined. Based on the equivalent magnetic reluctance of the joint region within the laminated layer, the equivalent magnetic permeability of the joint region under low magnetic induction intensity conditions, and the equivalent magnetic permeability of the joint region when the working magnetic induction intensity exceeds the critical magnetic induction intensity, the AC equivalent magnetic circuit model of the joint region under no DC bias magnetic conditions is generated.

6. The method according to claim 1, characterized in that, The steps for generating the equivalent magnetic circuit model under DC bias conditions include: Based on the DC magnetomotive force generated by the DC component of the winding current during the operation of the laminated iron core transformer, the DC bias reluctance corresponding to the joint area and the differential permeability of the silicon steel sheet material at the DC operating point are determined. The sum of the equivalent magnetic reluctance of the joint region within the laminated layer and the DC bias magnetic reluctance is determined as the equivalent magnetic reluctance of the joint region under DC bias conditions. Based on the equivalent permeability of the joint area under low magnetic induction intensity conditions, the equivalent permeability of the joint area when the working magnetic induction intensity exceeds the critical magnetic induction intensity, and the differential permeability of the silicon steel sheet material at the DC operating point, the equivalent permeability of the joint area under the DC biased magnetization conditions is determined. Based on the equivalent reluctance and equivalent permeability of the joint region under DC bias conditions, an equivalent magnetic circuit model under DC bias conditions is generated.

7. The method according to any one of claims 1-6, characterized in that, The steps for generating the two-dimensional equivalent planar structure include: The three-dimensional structure of the joint region of the laminated iron core transformer is projected along the main magnetic flux direction to generate a two-dimensional equivalent planar structure of the joint region.

8. A device for determining the characteristics of a laminated iron core transformer, characterized in that, include: Acquiring and determining units; The acquisition unit is used to acquire the magnetic induction intensity corresponding to the laminated iron core transformer; The determining unit is used to determine the magnetic characteristics and / or loss characteristics of the laminated core transformer based on the equivalent magnetic circuit model under DC bias conditions and the magnetic induction intensity. The equivalent magnetic circuit model under DC bias conditions is generated by equivalent correction of the magnetic circuit parameters based on the DC magnetomotive force generated by the DC component of the winding current during operation of the laminated core transformer. The magnetic circuit parameters correspond to the AC equivalent magnetic circuit model of the joint area of ​​the laminated core transformer under no DC bias conditions. The AC equivalent magnetic circuit model is generated based on the two-dimensional equivalent planar structure of the joint area, the magnetization curve and iron loss curve of the silicon steel sheet material used in the core of the laminated core transformer.

9. A computer device, characterized in that, The computer device includes: a processor and a memory; The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute the steps of the characteristic determination method for a laminated core transformer as described in any one of claims 1-7, according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method for determining the characteristics of a laminated core transformer as described in any one of claims 1-7.

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