A transformer coil design method and device

Abstract

The present invention belongs to the technical field of power distribution equipment design, and provides a transformer coil design method and device. The method comprises: establishing a transformer coil simulation test model, calculating the total heat generated by the load current, establishing an overall transformer simulation test model, performing temperature rise simulation calculation and optimizing the size parameters of the transformer coil simulation test model. Through the above steps, the technical problems existing in the prior art that the leakage flux cannot be tested under the power frequency conditions of a general factory laboratory and the influence of harmonics in the load current on the heating of the winding are solved, and the technical effect of conveniently performing simulation tests on the transformer coil and the transformer as a whole, and quickly optimizing the transformer coil and the overall structural design is achieved, avoiding multiple prototype manufacturing and retesting, improving test efficiency, and reducing development costs.

Description

Technical Field

[0001] The invention belongs to the technical field of power distribution equipment design, and in particular relates to a transformer coil design method and device. Background Art

[0002] Transformers are basic equipment for power transmission and distribution, and are widely used in industries, agriculture, transportation, urban communities, etc. Among them, rail transit transformers are used in advanced energy-feed substations, supporting 600V to 1500V DC power grids, and the loads are high-power IGBT bidirectional converters, which can realize bidirectional operation mode in the system, provide locomotive traction power in traction mode, and realize energy recovery in braking mode.

[0003] The loads carried by rail transit transformers are special. The load current not only has a large number of high-order harmonics, but also the phases of different-order harmonics in the two secondary windings are 180° opposite. Therefore, it is necessary to consider not only the impact of additional stray losses caused by high-order harmonics, but also the impact of additional losses caused by leakage magnetic flux caused by different phase currents. In product design, it is necessary to ensure that the winding temperature of the transformer under actual operating conditions does not exceed the limit of the insulation system to ensure its long-term safe operation.

[0004] However, the test current in general factory laboratories is under power frequency conditions, and it is impossible to input actual load currents containing harmonics and at different times and phases. Therefore, it is impossible to test the temperature rise of the transformer under actual load conditions in the factory laboratory. It is necessary to make a prototype and send it to the user end for joint debugging. If the prototype fails the joint debugging test with load, it is necessary to modify the transformer design again, manufacture a new prototype and then test it again. Repeated modifications and tests will lead to high testing costs, low testing efficiency and long development cycles. Summary of the invention

[0005] In order to overcome the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a transformer coil design method and device combined with electromagnetic thermal simulation.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] In a first aspect, the present invention provides a transformer coil design method, the method comprising:

[0008] Establish a transformer coil simulation test model;

[0009] Establishing the boundary conditions of the current magnetic field, performing a simulation test on the transformer coil simulation test model under the boundary conditions of the current magnetic field, and obtaining the total heat generated by the load current;

[0010] Establishing a transformer overall simulation test model excluding the transformer coil, wherein the transformer overall simulation test model includes a simulation test model of an iron core, and sleeves the transformer coil simulation test model on the outer side of the simulation test model of the iron core;

[0011] Perform temperature rise simulation calculation, use the total heat generated by the load current as the heat generated by the transformer coil simulation test model, assign a value to the heat generated by the iron core simulation test model, and calculate the operating temperature of the overall transformer simulation test model;

[0012] Compare the value of the operating temperature with a preset temperature limit value to obtain a difference parameter;

[0013] Optimizing the size parameters of the transformer coil simulation test model according to the difference parameters;

[0014] The above process is repeated until the value of the operating temperature is less than the preset temperature limit.

[0015] As a preferred implementation, the transformer coil simulation test model is established by the following steps:

[0016] Get the actual size parameters of the transformer coil;

[0017] Full-size modeling is performed according to actual size parameters of the transformer coil to obtain a simulation test model of the transformer coil.

[0018] As a preferred implementation, in the step of establishing the boundary conditions of the current magnetic field, conducting a simulation test on the transformer coil simulation test model under the boundary conditions to obtain the total heat generated by the load current:

[0019] Based on the structural characteristics of the transformer coil including the primary winding, the secondary winding and the tertiary winding, combined with the transformer coil simulation test model, electromagnetic field analysis and calculation are performed, and the influence of leakage magnetic field and harmonic waves is evaluated.

[0020] As a preferred implementation, after the step of optimizing the transformer coil simulation test model according to the difference parameters, it also includes changing the actual size parameters of the transformer coil according to the optimized transformer coil simulation test model.

[0021] As a preferred embodiment, in the step of performing full-size modeling according to the actual size parameters of the transformer coil, based on the structural characteristics of the transformer coil including a primary winding, a secondary winding and a tertiary winding, a full-size model of the conductor part is established according to the structure of the primary winding, the secondary winding and the tertiary winding.

[0022] In a second aspect, the present invention further provides a transformer coil design device, comprising:

[0023] Model simulation module, used to establish transformer coil simulation test model and transformer overall simulation test model excluding transformer coil;

[0024] Boundary setting module, used to establish boundary conditions of current magnetic field;

[0025] A first calculation module, configured to calculate the total heat generated by the load current based on the transformer coil simulation test model established by the model simulation module and the current magnetic field boundary conditions set by the boundary setting module;

[0026] a second calculation module, configured to calculate the operating temperature of the overall simulation test model based on the total calorific value of the load current calculated by the first calculation module, and to compare the value of the operating temperature with the temperature limit value based on a preset temperature limit value to obtain a difference parameter;

[0027] An optimization module is used to optimize the size parameters of the transformer coil simulation test model of the model simulation module according to the difference parameters calculated by the second calculation module.

[0028] As a preferred implementation, based on the structural features of the transformer coil including a primary winding, a secondary winding and a tertiary winding, the model simulation module establishes a full-size model of the conductor part according to the structures of the primary winding, the secondary winding and the tertiary winding respectively.

[0029] As a preferred implementation, the boundary setting module is also used to establish a boundary condition of temperature;

[0030] Based on the structural characteristics of the transformer coil including a primary winding, a secondary winding and a tertiary winding, combined with the transformer coil simulation test model and the transformer overall simulation test model, a simulation test is carried out under the boundary conditions of the temperature to obtain the temperature results of the primary winding, the secondary winding and the tertiary winding respectively.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] Based on the transformer coil design method and device, the technical problem that the leakage magnetic field and the influence of harmonics in the load current on the heating of the winding cannot be tested under the power frequency conditions of the general factory laboratory in the prior art is solved, and the technical effect of conveniently conducting simulation tests on the transformer coil and the iron core used for winding the transformer coil, and quickly optimizing the transformer coil and the overall structural design is achieved, avoiding multiple prototype manufacturing and retesting, improving test efficiency, and reducing development costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0034] Figure 1 Schematic diagram of the process of the transformer coil design method in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth in order to fully understand the present invention, and the embodiments described are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the art without making creative work are within the scope of protection of the present invention.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0037] Example 1

[0038] See also Figure 1 , Figure 1 : is a schematic diagram of the flow chart of the transformer coil design method in an embodiment of the present invention. Figure 1 The transformer coil design method described can be applied to a transformer coil design device, and the transformer coil design method can include the following operations:

[0039] Establish a transformer coil simulation test model.

[0040] Firstly, the actual size parameters of the existing prototype transformer coil are obtained, and then full-size modeling is performed according to the actual size parameters of the transformer coil to obtain a transformer coil simulation test model.

[0041] Calculate the total heat generated by the load current.

[0042] The boundary conditions of the current magnetic field are established in advance. Based on the structural characteristics of the transformer coil including the primary winding, the secondary winding and the tertiary winding, the primary winding in the transformer coil simulation test model is connected to the grid side, the secondary winding is connected to the load IGBT (Insulated Gate Bipolar Transistor, Chinese meaning is insulated gate bipolar transistor), and the tertiary winding is connected to the capacitor. The capacitor and the impedance of the tertiary winding itself form an LC filter loop. According to what is known to those skilled in the art, the LC filter is an element composed of an inductor and a capacitor, where L represents an inductor and C represents a capacitor. The function of the LC filter loop in this embodiment is the same as that of the LC filter, which can block unnecessary frequency signals or only allow the required frequency signals to pass. The three windings of the primary winding, the secondary winding and the tertiary winding all need to be simulated, calculated, analyzed and evaluated according to the actual induced current and load conditions. After the transformer coil simulation test model is established, the actual load current flowing into the secondary winding is simulated, and the operating current induced in the primary winding and the tertiary winding is simulated and calculated respectively.

[0043] Specifically, by inputting load currents of corresponding amplitude and phase in each order into the secondary winding, simulating the actual access capacitor parameters in the tertiary winding, the leakage magnetic distribution is obtained through simulation calculation, and the currents induced by each order current in the primary winding and the tertiary winding are calculated respectively, and the actual heating value is obtained through simulation calculation.

[0044] Preferably, in this operation, the transformer coil simulation test model is also combined to perform electromagnetic field analysis and calculation, and to evaluate the impact of magnetic leakage and harmonics.

[0045] Establish an overall simulation test model of the transformer.

[0046] According to the actual size parameters of the transformer coil of the existing prototype, the overall simulation test model of the transformer except the transformer coil is established in equal proportion. Preferably, the overall simulation test model of the transformer includes an iron core simulation test model, and the transformer coil simulation test model is set on the outside of the iron core simulation test model. Based on the structural characteristics that the transformer coil includes a primary winding, a secondary winding and a tertiary winding, a full-size model of the conductor part is established according to the structure of the primary winding, the secondary winding and the tertiary winding.

[0047] Carry out temperature rise simulation calculation.

[0048] The total calorific value of the load current obtained above is used as the calorific value of the transformer coil simulation test model, the calorific value of the iron core simulation test model is assigned, and the temperature boundary conditions are established. A thermal simulation test is carried out to calculate the operating temperature of the overall transformer simulation test model, and the operating temperature value is compared with the preset temperature limit to obtain the difference and obtain the difference parameter.

[0049] Optimize the size parameters of the transformer coil simulation test model.

[0050] If the difference parameter is greater than or equal to 0, the size of the transformer coil simulation test model is corrected and optimized according to the difference parameter obtained above. Specifically, the size parameters of the transformer coil simulation test model include the number of coil turns, the number of winding envelopes, and the cross-sectional size of the coil, such as Figure 1 As shown, the modified and optimized transformer coil simulation test model is simulated again under the boundary conditions of the current magnetic field and the temperature, and a new operating temperature is obtained again. The new operating temperature is compared with the preset temperature limit to obtain a new difference parameter, and this is repeated until the difference parameter is less than 0.

[0051] If the difference parameter is less than 0, the size optimization of the transformer coil simulation test model is stopped directly. The size of the transformer coil simulation test model at this time is the optimal size parameter. A new prototype is manufactured based on the size parameter and the size parameter of the transformer overall simulation test model. This operation method can achieve the technical effect of conveniently conducting simulation tests on the transformer coil and the transformer as a whole, quickly optimizing the transformer coil and the overall structural design, avoiding multiple prototype manufacturing and retesting, improving test efficiency, and reducing development costs.

[0052] Example 2

[0053] The embodiment of the present invention discloses a transformer coil design device, comprising:

[0054] A model simulation module, used to establish a transformer coil simulation test model and a simulation test model of an iron core for winding the transformer coil;

[0055] Boundary setting module, used to establish boundary conditions of current magnetic field;

[0056] A first calculation module is used to calculate the total heat generated by the load current based on the transformer coil simulation test model established by the model simulation module and the current magnetic field boundary conditions set by the boundary setting module;

[0057] The second calculation module is used to calculate the operating temperature of the overall transformer simulation test model based on the total calorific value of the load current calculated by the first calculation module, and compare the value of the operating temperature with the temperature limit value based on a preset temperature limit value to obtain a difference parameter;

[0058] The optimization module is used to optimize the size parameters of the transformer coil simulation test model of the model simulation module according to the difference parameters calculated by the second calculation module.

[0059] Among them, the model simulation module establishes a transformer coil simulation test model based on the actual size parameters of the transformer coil of the existing prototype. After the boundary setting module establishes the boundary conditions of the current magnetic field, based on the structural characteristics of the transformer coil including the primary winding, the secondary winding and the tertiary winding, the primary winding in the transformer coil simulation test model is connected to the grid side, the secondary winding is connected to the load IGBT, the tertiary winding is connected to the capacitor, and the capacitor and the impedance of the tertiary winding itself form an LC filter circuit. By inputting the corresponding amplitude and phase of each order load current in the secondary winding, simulating the actual connection capacitor parameters in the tertiary winding, the first calculation module can simulate and calculate the leakage magnetic distribution, and calculate the current induced by each order current in the primary winding and the tertiary winding, and simulate the calculation. The actual heat generation is calculated; the second calculation module calculates the operating temperature of the overall transformer simulation test model based on the total heat generation of the load current calculated by the first calculation module, and based on the preset temperature limit, compares the value of the operating temperature with the temperature limit to obtain the difference, and determines whether the value of the difference parameter is greater than or equal to 0. If it is judged to be yes, the optimization module optimizes the size parameters of the transformer coil simulation test model of the model simulation module according to the difference parameter, and repeats the above process until it is judged to be no; if it is judged to be no, the transformer coil design device stops working, and the size of the transformer coil simulation test model at this time is the optimal size parameter. According to the size parameter and the size parameter of the overall transformer simulation test model, a new prototype is manufactured. Such a setting achieves the technical effect of being able to conveniently perform simulation tests on the transformer coil and the transformer as a whole, quickly optimizing the transformer coil and the overall structural design, avoiding multiple prototype manufacturing and retesting, improving test efficiency, and reducing development costs.

[0060] Preferably, based on the structural characteristics that the transformer coil includes a primary winding, a secondary winding and a tertiary winding, the model simulation module establishes a full-size model of the conductor part according to the structures of the primary winding, the secondary winding and the tertiary winding respectively.

[0061] Preferably, the boundary setting module is also used to establish temperature boundary conditions; based on the structural characteristics of the transformer coil including the primary winding, the secondary winding and the tertiary winding, combined with the transformer coil simulation test model and the transformer overall simulation test model, a simulation test is carried out under the temperature boundary conditions to obtain the temperature results of the primary winding, the secondary winding and the tertiary winding respectively.

[0062] In summary, the transformer coil design method and device of the present invention have at least the following beneficial effects:

[0063] Based on the transformer coil design method and device, the technical problem that the leakage magnetic field and the influence of harmonics in the load current on the heating of the winding cannot be tested under the power frequency conditions of the general factory laboratory in the prior art is solved, and the technical effect of conveniently conducting simulation tests on the transformer coil and the transformer as a whole and quickly optimizing the transformer coil and the overall structural design is achieved, avoiding multiple prototype manufacturing and retesting, improving test efficiency and reducing development costs.

[0064] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A transformer coil design method, characterized in that: The method comprises: Establish a transformer coil simulation test model; Establishing the boundary conditions of the current magnetic field, performing a simulation test on the transformer coil simulation test model under the boundary conditions of the current magnetic field, and obtaining the total heat generated by the load current; Establishing a transformer overall simulation test model excluding the transformer coil, wherein the transformer overall simulation test model includes an iron core simulation test model, and the transformer coil simulation test model is sleeved on the outer side of the iron core simulation test model; Perform temperature rise simulation calculation, use the total heat generated by the load current as the heat generated by the transformer coil simulation test model, assign a value to the heat generated by the core simulation test model, and calculate the operating temperature of the overall transformer simulation test model; Compare the value of the operating temperature with a preset temperature limit value to obtain a difference parameter; Optimizing the size parameters of the transformer coil simulation test model according to the difference parameters; Repeating the process until the operating temperature is less than the preset temperature limit; The transformer coil simulation test model is established by the following steps: Get the actual size parameters of the transformer coil; Perform full-size modeling according to actual size parameters of the transformer coil to obtain a simulation test model of the transformer coil; In the step of establishing the boundary conditions of the current magnetic field, performing a simulation test on the transformer coil simulation test model under the boundary conditions to obtain the total heat generated by the load current: Based on the structural characteristics of the transformer coil including the primary winding, the secondary winding and the tertiary winding, combined with the transformer coil simulation test model, electromagnetic field analysis and calculation are performed, and the influence of leakage magnetic field and harmonic waves is evaluated.

2. The transformer coil design method according to claim 1, characterized in that: After the step of optimizing the transformer coil simulation test model according to the difference parameters, the method further includes changing the actual size parameters of the transformer coil according to the optimized transformer coil simulation test model.

3. The transformer coil design method according to claim 2, characterized in that: In the step of performing full-size modeling according to the actual size parameters of the transformer coil, based on the structural characteristics of the transformer coil including a primary winding, a secondary winding and a tertiary winding, full-size models of the conductor part are established according to the structures of the primary winding, the secondary winding and the tertiary winding.

4. A transformer coil design device, characterized in that: include: Model simulation module, used to establish transformer coil simulation test model and transformer overall simulation test model excluding transformer coil; Boundary setting module, used to establish boundary conditions of current magnetic field; A first calculation module, configured to calculate the total heat generated by the load current based on the transformer coil simulation test model established by the model simulation module and the current magnetic field boundary conditions set by the boundary setting module; A second calculation module calculates the operating temperature of the overall transformer simulation test model using the total calorific value of the load current calculated by the first calculation module, and based on a preset temperature limit, compares the value of the operating temperature with the temperature limit to obtain a difference parameter; An optimization module, configured to optimize the size parameters of the transformer coil simulation test model of the model simulation module according to the difference parameters calculated by the second calculation module; The transformer coil simulation test model is established by the following steps: Get the actual size parameters of the transformer coil; Perform full-size modeling according to actual size parameters of the transformer coil to obtain a simulation test model of the transformer coil; In the step of calculating the total heat generated by the load current by the first calculation module: Based on the structural characteristics of the transformer coil including the primary winding, the secondary winding and the tertiary winding, combined with the transformer coil simulation test model, electromagnetic field analysis and calculation are performed, and the influence of leakage magnetic field and harmonics is evaluated.

5. The transformer coil design device according to claim 4, characterized in that: Based on the structural characteristics that the transformer coil includes a primary winding, a secondary winding and a tertiary winding, the model simulation module establishes a full-size model of the conductor part according to the structures of the primary winding, the secondary winding and the tertiary winding respectively.

6. The transformer coil design device according to claim 4, characterized in that: The boundary setting module is also used to establish the boundary conditions of temperature; Based on the structural characteristics of the transformer coil including a primary winding, a secondary winding and a tertiary winding, combined with the transformer coil simulation test model and the transformer overall simulation test model, a simulation test is carried out under the boundary conditions of the temperature to obtain the temperature results of the primary winding, the secondary winding and the tertiary winding respectively.

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