Method and device for calculating turn-to-turn short-circuit current and loss of transformer

Abstract

The invention provides a transformer turn-to-turn short circuit current and loss calculation method and device, and the method comprises the steps: building a short circuit turn circuit model according to the short circuit turn information of a transformer when the transformer has a turn-to-turn short circuit; establishing a short-circuit turn electromagnetic field simulation model of the transformer, and calculating leakage inductance of transformer fault windings at different fault positions and different numbers of turns of short-circuit turn coils by adopting an energy method based on the short-circuit turn electromagnetic field simulation model; calculating the short-circuit turn short-circuit current of the transformer according to the short-circuit turn circuit model and the leakage inductance; and determining the short-circuit turn loss of the transformer according to the short-circuit turn short-circuit current and the short-circuit turn total resistance of the transformer. According to the invention, the accuracy of transformer turn-to-turn short-circuit current and loss calculation is improved.

Description

Technical Field

[0001] This invention relates to the field of transformer fault operation and maintenance technology, and in particular to a method and apparatus for calculating transformer inter-turn short-circuit current and losses. Background Technology

[0002] In actual operation, due to operating conditions and transformer manufacturing processes, overheating faults such as inter-turn short circuits in windings, overheating of leads or tap changer connections, and multiple grounding points in the core are inevitable. Under overheating fault conditions, abnormal heat generation occurs in the transformer. If not repaired in time, the fault will worsen and may eventually lead to serious accidents such as breakdown of the winding oil-paper insulation, phase-to-phase or phase-to-ground short circuits, winding burnout, or even transformer fire and explosion.

[0003] Transformers inevitably experience winding insulation degradation due to long-term exposure to electrical, thermal, and mechanical stresses, leading to a typical and frequent internal fault: inter-turn short circuits. However, existing calculation methods have significant limitations in addressing this fault, failing to accurately characterize the electromagnetic response under fault conditions. These methods are typically based on highly simplified circuit models or ideal electromagnetic field assumptions, unable to effectively represent the strong spatial leakage magnetic field distortion and nonlinear effects caused by short circuits in a few turns. This results in significant discrepancies between the estimated short-circuit circulating current amplitude and the resulting local eddy current losses and the actual situation. This inaccuracy renders the reliability of condition assessments and risk warnings based on these results insufficient, making it difficult to accurately and promptly determine the severity and development trend of the fault, thus failing to provide accurate data support for proactive and safe transformer operation and maintenance. Summary of the Invention

[0004] This invention provides a method and apparatus for calculating inter-turn short-circuit current and losses in transformers, thereby addressing the deficiencies in the calculation of inter-turn short-circuit current and losses in existing technologies and improving the accuracy of such calculations.

[0005] This invention provides a method for calculating the inter-turn short-circuit current of a transformer, comprising:

[0006] Based on the short-circuit turn information of the transformer, a short-circuit turn circuit model is established when the transformer experiences an inter-turn short circuit.

[0007] A simulation model of the electromagnetic field of the short-circuit turns of the transformer is established. Based on the simulation model, the leakage inductance of the transformer fault winding with different fault locations and different number of short-circuit turns is calculated using the energy method.

[0008] Based on the short-circuit turn circuit model and leakage inductance, calculate the short-circuit current of the transformer's short-circuit turns.

[0009] According to the present invention, a method for calculating the inter-turn short-circuit current of a transformer is provided, wherein the short-circuit turn information includes the total resistance of the short-circuit turn, the leakage inductance of the short-circuit turn, the number of turns of the short-circuit turn coil, the main magnetic flux corresponding to the transformer magnetic column where the short-circuit turn is located, the short-circuit turn potential, and the short-circuit turn current.

[0010] The total resistance of the short-circuit turn includes the resistance of the short-circuit turn coil wire and the contact resistance at the fault location.

[0011] According to the method for calculating the inter-turn short-circuit current of a transformer provided by the present invention, the formula for the short-circuit turn circuit model is as follows:

[0012]

[0013] Among them, R s It is the total resistance of the short-circuit turns, L δ It is the leakage inductance of the short-circuit turn, N s It is the number of turns in the short-circuit coil. It is the main magnetic flux corresponding to the transformer magnetic column where the short-circuit turn is located. For short-circuit turn potential, ω is the short-circuit turn current, f is the current frequency, j is the complex number operator, and ω is the current angular frequency.

[0014] According to the present invention, a method for calculating the inter-turn short-circuit current of a transformer is provided, wherein the main magnetic flux... Satisfy the following formula:

[0015]

[0016] in, It is the effective value of the induced electromotive force of the normal winding of the transformer corresponding to the transformer magnetic column where the short-circuit turn is located.

[0017] According to the method for calculating the inter-turn short-circuit current of a transformer provided by the present invention, the formula for the short-circuit turn circuit model is as follows:

[0018]

[0019] or,

[0020] Among them, R s It is the total resistance of the short-circuit turns, L δ It is the leakage inductance of the short-circuit turn, N s It is the number of turns in the short-circuit coil. It is the short-circuit turn current. and These are the transformer primary winding potential and transformer secondary winding potential corresponding to the transformer magnetic column where the short-circuit turn is located, respectively. and These are the high-voltage port voltage and low-voltage port voltage of the transformer, respectively; j is a complex number operator; and ω is the current angular frequency.

[0021] According to the present invention, a method for calculating the inter-turn short-circuit current of a transformer is provided, wherein the transformer primary winding potential corresponding to the transformer magnetic column where the short-circuit turn is located is... The formula is:

[0022]

[0023] The transformer secondary winding potential corresponding to the transformer magnetic column where the short-circuit turn is located The formula is:

[0024]

[0025] in, It is the main magnetic flux corresponding to the transformer magnetic column where the short-circuit turn is located. and These are the high-voltage and low-voltage side currents of the transformer, respectively. N1 and N2 are the number of turns of the high-voltage and low-voltage side windings of the transformer, respectively. f is the current frequency. Z1 and Z2 are the leakage impedances of the high-voltage winding and the low-voltage winding of the transformer, respectively.

[0026] According to the present invention, a method for calculating the inter-turn short-circuit current of a transformer is provided. Based on the electromagnetic field simulation model of the short-circuit turn, the leakage inductance of the transformer fault winding with different fault locations and different numbers of short-circuit turns is calculated using the energy method based on the following formula:

[0027]

[0028] Among them, W m L is the magnetic field energy generated by the transformer at different fault locations and with different numbers of short-circuit coil turns, obtained from the short-circuit turn electromagnetic field simulation model. δ It is the short-circuit leakage inductance, B and H are the magnetic field density and magnetic field strength of the entire transformer region excluding the core, respectively, and I P This is the short-circuit turn current value.

[0029] This invention also provides a method for calculating transformer inter-turn short-circuit loss, applied to the transformer inter-turn short-circuit current calculation method according to any of the above claims, comprising:

[0030] The total resistance of the short-circuit turns of the transformer is determined by the resistance of the short-circuit coil wires and the contact resistance at the fault location.

[0031] The short-circuit turn loss of the transformer is determined based on the short-circuit current and total resistance of the short-circuit turns.

[0032] The present invention also provides a transformer inter-turn short-circuit current device, comprising:

[0033] A module is established to build a short-circuit turn circuit model when the transformer experiences an inter-turn short circuit, based on the short-circuit turn information of the transformer.

[0034] The first calculation module is used to establish a short-circuit turn electromagnetic field simulation model of the transformer, and to calculate the leakage inductance of the transformer fault winding with different fault locations and different number of short-circuit turn coils based on the short-circuit turn electromagnetic field simulation model using the energy method.

[0035] The second calculation module is used to calculate the short-circuit current of the transformer's short-circuit turns based on the short-circuit turn circuit model and leakage inductance.

[0036] The present invention also provides a transformer inter-turn short-circuit loss device, comprising:

[0037] The third calculation module is used to determine the total resistance of the transformer's short-circuit turns based on the resistance of the short-circuit coil wires and the contact resistance at the fault location.

[0038] The fourth calculation module is used to determine the short-circuit turn loss of the transformer based on the short-circuit current and the total resistance of the short-circuit turns.

[0039] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the transformer inter-turn short-circuit current or loss calculation method as described above.

[0040] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the transformer inter-turn short-circuit current or loss method as described above.

[0041] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the transformer inter-turn short-circuit current or loss method as described above.

[0042] The present invention provides a method and apparatus for calculating transformer inter-turn short-circuit current and losses. By establishing a refined transformer electromagnetic field model and employing the energy method to calculate leakage inductance under fault conditions, the accuracy of the model is improved, providing a reliable theoretical basis for subsequent calculations. It possesses dynamic adaptive capabilities to fault location, severity, and development. Through parametric simulation analysis of different short-circuit conditions, this method accurately reflects the impact of changes in fault phase, location, and number of turns on electrical parameters, and can simulate the fault evolution process caused by changes in contact resistance, significantly improving the accuracy and applicability of condition assessment. The output short-circuit current and loss results can be directly used in transformer condition monitoring and fault early warning systems, providing key data support for insulation thermal aging assessment, fault risk assessment, and predictive maintenance, and has significant engineering application value. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1 This is a flowchart illustrating the method for calculating the inter-turn short-circuit current of a transformer provided by the present invention.

[0045] Figure 2 This is a schematic diagram of the three-dimensional simulation model for solving leakage inductance in the transformer inter-turn short-circuit current calculation method provided by the present invention;

[0046] Figure 3 This is a schematic diagram of the curve showing the change of short-circuit current of a short-circuit turn with the total resistance of the short-circuit turn circuit in the transformer inter-turn short-circuit current calculation method provided by the present invention.

[0047] Figure 4 This is a schematic diagram of the curve showing the change of short-circuit loss of short-circuit turns with the total resistance of the short-circuit turn circuit in the transformer inter-turn short-circuit current calculation method provided by the present invention.

[0048] Figure 5 This is a flowchart illustrating the method for calculating transformer inter-turn short-circuit losses provided by the present invention;

[0049] Figure 6 This is a schematic diagram of the structure of the transformer inter-turn short-circuit current calculation device provided by the present invention;

[0050] Figure 7 This is a schematic diagram of the transformer inter-turn short-circuit loss calculation device provided by the present invention. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0052] The following is combined Figure 1 A method for calculating the inter-turn short-circuit current of a transformer according to the present invention includes:

[0053] Step 101: Based on the short-circuit turn information of the transformer, establish a short-circuit turn circuit model when the transformer experiences an inter-turn short circuit;

[0054] Step 102: Establish a short-circuit turn electromagnetic field simulation model of the transformer, and use the energy method to calculate the leakage inductance of the transformer fault winding at different fault locations and with different short-circuit turn coil turns based on the short-circuit turn electromagnetic field simulation model.

[0055] Step 103: Calculate the short-circuit current of the transformer's short-circuit turns based on the short-circuit turn circuit model and leakage inductance.

[0056] The current fault location of the transformer and the current leakage inductance of the transformer fault winding corresponding to the current number of short-circuit turns can be determined. The short-circuit current of the current short-circuit turns of the transformer can be calculated based on the short-circuit turn circuit model of the transformer and the current leakage inductance.

[0057] Compared with the prior art, the transformer inter-turn short-circuit current calculation method provided by the present invention has the following significant advantages:

[0058] (1) By establishing a detailed three-dimensional electromagnetic field simulation model, the short-circuit leakage inductance (L) under fault conditions is accurately calculated using the A,φ-A method and the energy method. δ This method fully considers complex factors such as spatial leakage magnetic field distortion caused by short-circuit faults, core structure, and winding arrangement, fundamentally ensuring the core parameter L. δ The high accuracy of the calculations laid a solid foundation for the accurate calculation of subsequent short-circuit current and losses.

[0059] (2) Strong adaptability, able to reflect differences in fault location and severity: The core parameter of this method is leakage inductance L. δ The results were obtained through targeted simulations of specific fault scenarios (such as the top two turns of phase A and the middle five turns of phase B). This demonstrates that the method of this invention is sensitive to the specific location and severity of the fault, and can dynamically adapt to various potential fault scenarios, overcoming the shortcomings of existing methods that use fixed parameters, resulting in weak generalization ability.

[0060] (3) It achieves a precise mapping from "field" to "path", with strong engineering applicability: This invention ingeniously integrates the complex electromagnetic field finite element analysis results (calculation L) δ This approach combines field-circuit coupling with concise circuit equations. This "field-circuit coupling" approach ensures the physical accuracy of the calculation results while significantly reducing the enormous resource and time costs required for pure field calculations. This makes the method both highly accurate and efficient, making it very suitable for practical engineering applications and providing a possibility for developing online monitoring and diagnostic algorithms.

[0061] (4) By accurately calculating the short-circuit current and local overheat loss (abnormal heat source) under fault conditions, the present invention can provide crucial data for predicting the temperature rise at the fault point, assessing the thermal aging rate of the insulating paperboard, and preventing serious accidents such as fires and explosions.

[0062] Based on the above embodiments, the short-circuit turn information in this embodiment includes the total resistance of the short-circuit turn, the leakage inductance of the short-circuit turn, the number of turns of the short-circuit turn coil, the main magnetic flux corresponding to the transformer magnetic column where the short-circuit turn is located, the short-circuit turn potential, and the short-circuit turn current;

[0063] The total resistance of the short-circuit turn includes the resistance of the short-circuit turn coil wire and the contact resistance at the fault location.

[0064] Based on the above embodiments, the formula for the short-circuit turn circuit model in this embodiment is:

[0065]

[0066] Among them, R s It is the total resistance of the short-circuit turns, L δ It is the leakage inductance of the short-circuit turn, N s It is the number of turns in the short-circuit coil. It is the main magnetic flux corresponding to the transformer magnetic column where the short-circuit turn is located. For short-circuit turn potential, ω is the short-circuit turn current, f is the current frequency, j is the complex number operator, and ω is the current angular frequency.

[0067] Short-circuit turn potential With transformer short-circuit turn current Same direction, short circuit current With main magnetic flux It satisfies the right-hand screw rule.

[0068] Based on the above embodiments, the main magnetic flux in this embodiment Satisfy the following formula:

[0069]

[0070] in, It is the effective value of the induced electromotive force of the normal winding of the transformer corresponding to the transformer magnetic column where the short-circuit turn is located.

[0071] Based on the above embodiments, the formula for the short-circuit turn circuit model in this embodiment is:

[0072]

[0073] or,

[0074] Among them, R s It is the total resistance of the short-circuit turns, L δ It is the leakage inductance of the short-circuit turn, N s It is the number of turns in the short-circuit coil. It is the short-circuit turn current. and These are the transformer primary winding potential and transformer secondary winding potential corresponding to the transformer magnetic column where the short-circuit turn is located, respectively. and These are the high-voltage port voltage and low-voltage port voltage of the transformer, respectively; j is a complex number operator; and ω is the current angular frequency.

[0075] Based on the operating characteristics of the transformer, it can be seen that when a minor inter-turn short circuit fault occurs in the transformer (i.e., when the number of short-circuited turns in the transformer is small), the change in the external voltage of the transformer is small. Therefore, when the leakage impedances Z1 and Z2 of the high and low voltage windings of the transformer are ignored, the short-circuit circuit model when an inter-turn short circuit occurs can be transformed into formula (4) or formula (5).

[0076] Therefore, by monitoring the voltage of the high-voltage or low-voltage winding on the magnetic column where the short-circuited turn is located, and by calculating the leakage reactance corresponding to the short-circuited turn, the short-circuit current corresponding to the short-circuited turn can be obtained. When the short-circuited winding occurs on the high-voltage side, the short-circuited turn current is in the opposite direction to the primary coil current and in the same direction as the secondary coil current.

[0077] Based on the above embodiments, in this embodiment the transformer primary winding potential corresponding to the transformer magnetic column where the short-circuit turn is located. The formula is:

[0078]

[0079] The transformer secondary winding potential corresponding to the transformer magnetic column where the short-circuit turn is located The formula is:

[0080]

[0081] in, It is the main magnetic flux corresponding to the transformer magnetic column where the short-circuit turn is located. and These are the high-voltage and low-voltage side currents of the transformer, respectively. N1 and N2 are the number of turns of the high-voltage and low-voltage side windings of the transformer, respectively. f is the current frequency. Z1 and Z2 are the leakage impedances of the high-voltage winding and the low-voltage winding of the transformer, respectively.

[0082] electric potential With transformer high-voltage port current Same direction, electric potential With transformer low-voltage port current Same direction, transformer high-voltage port voltage With current Same direction, transformer low-voltage port voltage With current Same direction, With main magnetic flux It satisfies the right-hand screw rule.

[0083] Based on the above embodiments, this embodiment uses the following formula to calculate the leakage inductance of the transformer fault winding with different fault locations and different numbers of short-circuit turns using the energy method based on the short-circuit turn electromagnetic field simulation model:

[0084]

[0085] Among them, W m L is the magnetic field energy generated by the transformer at different fault locations and with different numbers of short-circuit coil turns, obtained from the short-circuit turn electromagnetic field simulation model. δ It is the short-circuit leakage inductance, B and H are the magnetic field density and magnetic field strength of the entire transformer region excluding the core, respectively, and I P This is the short-circuit turn current value.

[0086] As can be seen from formulas (4) and (5), the leakage inductance of the short-circuit turn is a key calculation parameter for calculating the fault current under inter-turn short-circuit conditions. This embodiment establishes an electromagnetic field simulation model containing the transformer's short-circuit turns. Based on A, Electromagnetic field simulation analysis method, using the energy method to analyze the leakage inductance L of transformer fault windings with different short-circuit turns. δ Calculations were performed.

[0087] The established three-dimensional magnetic field solution model for transformer leakage inductance is as follows: Figure 2 As shown in Table 1, the simulation results for different short-circuit fault scenarios and the corresponding short-circuit leakage inductance calculations are presented in Table 1.

[0088] Table 1. Different short-circuit fault conditions and corresponding short-circuit leakage inductance.

[0089]

[0090] When a two-turn short circuit occurs at the top of the A-phase high-voltage winding, the calculated leakage inductance L is considered. δ Using formula (4) or (5) for calculating short-circuit current, and taking into account the contact resistance considering the degree of insulation degradation of the short-circuit turns, the calculated short-circuit current and short-circuit loss of the short-circuit turns under rated load vary with the total resistance Rs of the short-circuit turn circuit as follows: Figure 3 and Figure 4 As shown.

[0091] like Figure 5 As shown, this embodiment provides a method for calculating transformer inter-turn short-circuit current loss, applicable to the transformer inter-turn short-circuit current calculation method in any of the above embodiments, including:

[0092] Step 501: Determine the total resistance of the short-circuit turns of the transformer based on the resistance of the short-circuit coil wires and the contact resistance at the fault location.

[0093] Step 502: Determine the short-circuit turn loss of the transformer based on the short-circuit current and total resistance of the short-circuit turns.

[0094] Analysis of the heating characteristics of transformers under inter-turn short-circuit faults reveals that after an inter-turn short-circuit fault occurs, the short-circuit coil portion is a good metallic conductor with low resistance. Therefore, the abnormal heating under inter-turn short-circuit faults is mainly concentrated at the fault location, i.e., it is mainly affected by the magnitude of the contact transition resistance at the short-circuit location.

[0095] For example, the rated current of the high-voltage winding of the S13-M-200kVA / 10kV transformer is 6.67A. According to the calculation results, when a two-turn short circuit occurs at the top of the A-phase high-voltage winding, the direct metallic short circuit (with a contact resistance close to 0) will generate a short-circuit current in the short-circuit turn that is about 110 times higher than the rated current of the high-voltage winding. At this time, the heat emitted from the fault location of the short-circuit turn (close to 10kW) is enough to burn out the transformer winding. This is why, after an inter-turn short circuit fault occurs in the transformer winding, as the degree of the short circuit fault continues to deepen, the contact resistance at the fault location continues to decrease. In the later stage of the fault, the copper wire of the short-circuit turn will melt under the action of the huge short-circuit current, ultimately causing the transformer to have to be taken out of operation.

[0096] When a two-turn short circuit occurs at the top of the A-phase high-voltage winding, the contact resistance and short-circuit current of the short-circuited turns under different heating powers are further calculated, as shown in Table 2. It can be seen that in the initial stage of a short-circuit fault, when the contact resistance is large and the short-circuit current is small, a relatively large heating power (hundred watts) can be achieved at the fault location. Therefore, by monitoring the changes in the transformer's heating characteristics and using this to reflect the abnormal heating state of the transformer, it is possible to identify the fault in its early stages of overheating.

[0097] Table 2. Contact resistance and short-circuit current for different heating powers.

[0098]

[0099] The key aspect of this invention lies in proposing a precise modeling method based on three-dimensional field-circuit coupling. This method effectively overcomes the shortcomings of insufficient accuracy in traditional simplified models by establishing a refined electromagnetic field model of the transformer and using the energy method to calculate the leakage inductance under fault conditions, thus providing a reliable theoretical foundation for subsequent calculations.

[0100] Secondly, this patent possesses dynamic adaptive capabilities regarding fault location, severity, and development. Through parametric simulation analysis of different short-circuit conditions, this method can accurately reflect the impact of changes in fault phase, location, and number of turns on electrical parameters, and can simulate the fault evolution process caused by changes in contact resistance, significantly improving the accuracy and applicability of condition assessment.

[0101] Finally, this patent provides a clear path for engineering applications. Its output short-circuit current and loss results can be directly used in transformer condition monitoring and fault early warning systems, providing crucial data support for insulation thermal aging assessment, fault risk judgment, and predictive maintenance, thus possessing significant engineering application value.

[0102] The transformer inter-turn short-circuit current calculation device provided by the present invention is described below. The transformer inter-turn short-circuit current calculation device described below and the transformer inter-turn short-circuit current calculation method described above can be referred to in correspondence.

[0103] like Figure 6 As shown, a transformer inter-turn short-circuit current calculation device includes:

[0104] The module 601 is used to establish a short-circuit turn circuit model when the transformer experiences an inter-turn short circuit based on the short-circuit turn information of the transformer.

[0105] The first calculation module 602 is used to establish a short-circuit turn electromagnetic field simulation model of the transformer, and to calculate the leakage inductance of the transformer fault winding with different fault locations and different number of short-circuit turn coils based on the short-circuit turn electromagnetic field simulation model using the energy method.

[0106] The second calculation module 603 is used to calculate the short-circuit current of the transformer's short-circuit turns based on the short-circuit turn circuit model and leakage inductance.

[0107] The transformer inter-turn short-circuit loss calculation device provided by the present invention is described below. The transformer inter-turn short-circuit loss calculation device described below can be referred to in correspondence with the transformer inter-turn short-circuit loss calculation method described above.

[0108] like Figure 7 As shown, a transformer inter-turn short-circuit loss device includes:

[0109] The third calculation module 701 is used to determine the total resistance of the short-circuit turns of the transformer based on the resistance of the short-circuit coil wires and the contact resistance at the fault location.

[0110] The fourth calculation module 702 is used to determine the short-circuit turn loss of the transformer based on the short-circuit current and the total resistance of the short-circuit turns.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the inter-turn short-circuit current of a transformer, characterized in that, include: Based on the short-circuit turn information of the transformer, a short-circuit turn circuit model is established when the transformer experiences an inter-turn short circuit. A simulation model of the electromagnetic field of the short-circuit turns of the transformer is established. Based on the simulation model, the leakage inductance of the transformer fault winding with different fault locations and different number of short-circuit turns is calculated using the energy method. Based on the short-circuit turn circuit model and leakage inductance, calculate the short-circuit current of the transformer's short-circuit turns.

2. The method for calculating the inter-turn short-circuit current of a transformer according to claim 1, characterized in that, The short-circuit turn information includes the total resistance of the short-circuit turn, the leakage inductance of the short-circuit turn, the number of turns of the short-circuit turn coil, the main magnetic flux corresponding to the transformer magnetic column where the short-circuit turn is located, the short-circuit turn potential, and the short-circuit turn current. The total resistance of the short-circuit turn includes the resistance of the short-circuit turn coil wire and the contact resistance at the fault location.

3. The method for calculating the inter-turn short-circuit current of a transformer according to claim 2, characterized in that, The formula for the short-circuit turn circuit model is: Among them, R s It is the total resistance of the short-circuit turns, L δ It is the leakage inductance of the short-circuit turn, N s It is the number of turns in the short-circuit coil. It is the main magnetic flux corresponding to the transformer magnetic column where the short-circuit turn is located. For short-circuit turn potential, ω is the short-circuit turn current, f is the current frequency, j is the complex number operator, and ω is the current angular frequency.

4. The method for calculating the inter-turn short-circuit current of a transformer according to claim 3, characterized in that, The main magnetic flux Satisfy the following formula: in, It is the effective value of the induced electromotive force of the normal winding of the transformer corresponding to the transformer magnetic column where the short-circuit turn is located.

5. The method for calculating the inter-turn short-circuit current of a transformer according to claim 2, characterized in that, The formula for the short-circuit turn circuit model is: or, Among them, R s It is the total resistance of the short-circuit turns, L δ It is the leakage inductance of the short-circuit turn, N s It is the number of turns in the short-circuit coil. It is the short-circuit turn current. and These are the transformer primary winding potential and transformer secondary winding potential corresponding to the transformer magnetic column where the short-circuit turn is located, respectively. and These are the high-voltage port voltage and low-voltage port voltage of the transformer, respectively; j is a complex number operator; and ω is the current angular frequency.

6. The method for calculating the inter-turn short-circuit current of a transformer according to claim 5, characterized in that, The transformer primary winding potential corresponding to the transformer magnetic column where the short-circuit turn is located The formula is: The transformer secondary winding potential corresponding to the transformer magnetic column where the short-circuit turn is located The formula is: in, It is the main magnetic flux corresponding to the transformer magnetic column where the short-circuit turn is located. and These are the high-voltage and low-voltage side currents of the transformer, respectively. N1 and N2 are the number of turns of the high-voltage and low-voltage side windings of the transformer, respectively. f is the current frequency. Z1 and Z2 are the leakage impedances of the high-voltage winding and the low-voltage winding of the transformer, respectively.

7. The method for calculating the inter-turn short-circuit current of a transformer according to any one of claims 1-6, characterized in that, The leakage inductance of the transformer fault winding with different fault locations and different numbers of short-circuit turns is calculated using the energy method based on the short-circuit turn electromagnetic field simulation model using the following formula: Among them, W m L is the magnetic field energy generated by the transformer at different fault locations and with different numbers of short-circuit coil turns, obtained from the short-circuit turn electromagnetic field simulation model. δ It is the short-circuit leakage inductance, B and H are the magnetic field density and magnetic field strength of the entire transformer region excluding the core, respectively, and I P This is the short-circuit turn current value.

8. A method for reducing inter-turn short-circuit loss in a transformer, characterized in that, The method for calculating the inter-turn short-circuit current of a transformer, applicable to any one of claims 1-7, includes: The total resistance of the short-circuit turns of the transformer is determined by the resistance of the short-circuit coil wires and the contact resistance at the fault location. The short-circuit turn loss of the transformer is determined based on the short-circuit current and total resistance of the short-circuit turns.

9. A transformer inter-turn short-circuit current calculation device, characterized in that, include: A module is established to build a short-circuit turn circuit model when the transformer experiences an inter-turn short circuit, based on the short-circuit turn information of the transformer. The first calculation module is used to establish a short-circuit turn electromagnetic field simulation model of the transformer, and to calculate the leakage inductance of the transformer fault winding with different fault locations and different number of short-circuit turn coils based on the short-circuit turn electromagnetic field simulation model using the energy method. The second calculation module is used to calculate the short-circuit current of the transformer's short-circuit turns based on the short-circuit turn circuit model and leakage inductance.

10. A transformer inter-turn short-circuit loss device, characterized in that, include: The third calculation module is used to determine the total resistance of the transformer's short-circuit turns based on the resistance of the short-circuit coil wires and the contact resistance at the fault location. The fourth calculation module is used to determine the short-circuit turn loss of the transformer based on the short-circuit current and the total resistance of the short-circuit turns.

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