A method and system for analyzing and modeling inter-turn short-circuit faults in electromagnetic voltage transformers

Abstract

The present invention discloses a method and system for analyzing and modeling electromagnetic voltage transformer turn-to-turn short-circuit faults. The method comprises the following steps: obtaining parameters of the electromagnetic voltage transformer; performing finite element simulation on the electromagnetic voltage transformer using a transient collaborative simulation method based on a winding grouping method and the parameters, and establishing a finite element turn-to-turn short-circuit fault model of the electromagnetic voltage transformer; calculating the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer is short-circuited; and then establishing an analytical model for the electromagnetic voltage transformer turn-to-turn short-circuit fault, and analyzing and calculating the voltage and current of the primary and secondary windings of the electromagnetic voltage transformer under different positions, different short-circuit turn ratios, and different transition resistance operating modes. The method can quantitatively provide the voltage and current of the primary and secondary windings of the electromagnetic voltage transformer under different positions, different short-circuit turn ratios, and different transition resistance operating modes, and the error is relatively small compared to the finite element simulation results.

Description

Technical Field

[0001] The present invention belongs to the field of power systems and relates to analytical modeling of voltage transformer short-circuit faults, and in particular to a method and system for analytical modeling of external characteristics of electromagnetic voltage transformer turn-to-turn short-circuit faults. Background Art

[0002] The continuous increase in the capacity of generator sets has led to higher requirements for the reliability of power equipment for the safe and stable operation of the power grid. The electromagnetic voltage transformer at the generator outlet plays an important role in measuring the voltage, power, and electric energy at the generator end, as well as collecting voltage from the relay protection, excitation system, and speed control system. The electromagnetic voltage transformer at the generator outlet is directly connected to the export busbar. When a turn-to-turn short circuit occurs, it will cause the generator stator grounding protection to operate, resulting in an unplanned shutdown of the generator set. Studying the external characteristics of the electromagnetic voltage transformer turn-to-turn short circuit fault is of great significance for quantitatively analyzing the external characteristics of the voltage transformer turn-to-turn short circuit fault, understanding the impact of the generator-end voltage transformer turn-to-turn short circuit fault on the stator grounding protection, improving the corresponding protection principle, and ensuring the safety and stability of the power system. Summary of the Invention

[0003] In order to solve the above-mentioned external characteristics problem of electromagnetic voltage transformer inter-turn short-circuit fault, the present invention provides an electromagnetic voltage transformer inter-turn short-circuit fault analytical modeling method and system, establishes an electromagnetic voltage transformer finite element short-circuit fault model suitable for winding grouping technology, and establishes an electromagnetic voltage transformer short-circuit fault analytical model based on the electromagnetic voltage transformer finite element short-circuit fault model.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A method for analyzing and modeling an electromagnetic voltage transformer turn-to-turn short-circuit fault, comprising:

[0006] Get the parameters of electromagnetic voltage transformer;

[0007] Based on the winding grouping method and the parameters, a finite element simulation of the electromagnetic voltage transformer is performed using a transient collaborative simulation method to establish a finite element turn-to-turn short-circuit fault model of the electromagnetic voltage transformer; the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has an turn-to-turn short-circuit are calculated;

[0008] Based on the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has an inter-turn short circuit, an analytical model for the inter-turn short circuit fault of the electromagnetic voltage transformer is established. The voltage and current of the primary and secondary windings of the electromagnetic voltage transformer are analytically calculated under different positions, different short-circuit turns ratios, and different transition resistance operating modes.

[0009] As a further improvement of the present invention, the parameters of the electromagnetic voltage transformer are obtained, including: the electromagnetic voltage transformer grid-connected rated voltage V1, rated power frequency f, voltage ratio K u , voltage transformer core magnetization curve and winding structure parameters, primary winding grouping number n, transition resistance r, and fault location.

[0010] As a further improvement of the present invention, the winding structure parameters include the length, width and height of the winding structure.

[0011] As a further improvement of the present invention, the finite element simulation of the electromagnetic voltage transformer is performed by a transient collaborative simulation method based on the winding grouping method, including:

[0012] A winding consisting of a group of series coils is divided into multiple series concentric cylindrical structures. Each concentric cylindrical structure is equivalent to a multi-turn winding, and the gap between each two concentric cylinders is the average of the sum of the gaps of the multi-turn windings. Based on this, a simplified finite element short-circuit fault model of an electromagnetic voltage transformer is established, which includes an excitation power supply, a transition resistor, and a connection circuit between each winding group. Finite element simulation of the electromagnetic voltage transformer is performed using a transient collaborative simulation method.

[0013] As a further improvement of the present invention, the electromagnetic voltage transformer turn-to-turn short-circuit fault analytical model is a complex frequency domain impedance model when the electromagnetic voltage transformer turns are short-circuited. The specific expression of the complex frequency domain impedance model when the turns between the i-th group and the j-th group of the electromagnetic voltage transformer are short-circuited is:

[0014] u 21 =Z p ·i 21 =A 2(n+1) ·Z (n+1)(n+1) ·V (n+1)2 ·i 21

[0015] in:

[0016]

[0017]

[0018]

[0019] M1 mn is the matrix M1 (j-i+1)×(i-1) Elements in M2 mn is the matrix M2 (j-i+1)×(n-j) Elements in M3 mn is the matrix M3 (n-i+1)×(n-i+1) The elements in R 1m is the matrix R 1×(j-i+1) The element in , r is the transition resistance.

[0020] As a further improvement of the present invention, the electromagnetic voltage transformer turn-to-turn short-circuit fault analysis model is established based on the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer turns are short-circuited, specifically including:

[0021] The turns between the i-th and j-th groups of the electromagnetic voltage transformer are short-circuited. According to Kirchhoff's current law:

[0022] i m1 =i r +i i (1)

[0023] Where i m1 is the grounding primary winding inlet current of the electromagnetic voltage transformer, i r is the fault current flowing through the transition resistor, i i Divert the fault current flowing through the fault winding;

[0024] The fault current splitting expression of the fault winding circuit is:

[0025] i i =h·i m1 (2)

[0026] in:

[0027]

[0028]

[0029] R 1×(j-i+1) =[R i R i+1 … R j ],

[0030] M1 mn is the matrix M1 (j-i+1)×(i-1) Elements in M2 mn is the matrix M2 (j-i+1)×(n-j) Elements in M3 mn is the matrix M3 (n-i+1)×(n-i+1) The elements in R 1m is the matrix R 1×(j-i+1) The element in , r is the transition resistance;

[0031] When the turns between the first end of the i-th group and the end of the j-th group of the electromagnetic voltage transformer are short-circuited, the primary current i and the current i flowing through each winding are i The expression between them is:

[0032] i i =V (n+1)2 ·i (3)

[0033] in:

[0034]

[0035] According to equations (1), (2), and (3), the analytical model of the electromagnetic voltage transformer with inter-turn short circuit between the head end of group i and the end end of group j is obtained:

[0036] u 21 =Z p ·i 21 =A 2(n+1) ·Z (n+1)(n+1) ·V (n+1)2 ·i 21 (4)

[0037] in:

[0038] An electromagnetic voltage transformer turn-to-turn short-circuit fault analysis and modeling system, comprising:

[0039] A parameter acquisition module is used to obtain parameters of an electromagnetic voltage transformer;

[0040] A fault model establishment module is used to perform finite element simulation on the electromagnetic voltage transformer through a transient collaborative simulation method based on the winding grouping method and the parameters, establish a finite element turn-to-turn short-circuit fault model of the electromagnetic voltage transformer, and calculate the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has an inter-turn short circuit;

[0041] The analytical model establishment module is used to establish an analytical model for electromagnetic voltage transformer turn-to-turn short-circuit faults based on the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has a turn-to-turn short-circuit. It also analytically calculates the voltage and current of the primary and secondary windings of the electromagnetic voltage transformer under different positions, different short-circuit turns ratios, and different transition resistance operating modes.

[0042] As a further improvement of the present invention, in the analytical model establishment module, the electromagnetic voltage transformer turn-to-turn short-circuit fault analytical model is a complex frequency domain impedance model when the electromagnetic voltage transformer turn-to-turn short-circuit fault occurs. The specific expression of the complex frequency domain impedance model when the electromagnetic voltage transformer turns between the i-th group and the j-th group are short-circuited is:

[0043] u 21 =Z p ·i 21 =A 2(n+1) ·Z (n+1)(n+1) ·V (n+1)2 ·i 21

[0044] in:

[0045]

[0046]

[0047]

[0048] M1 mn is the matrix M1 (j-i+1)×(i-1) Elements in M2 mn is the matrix M2 (j-i+1)×(n-j) Elements in M3 mn is the matrix M3 (n-i+1)×(n-i+1) The elements in R 1m is the matrix R 1×(j-i+1) The element in , r is the transition resistance.

[0049] An electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the electromagnetic voltage transformer turn-to-turn short-circuit fault analysis modeling method are implemented.

[0050] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the electromagnetic voltage transformer turn-to-turn short-circuit fault analysis and modeling method.

[0051] Compared with the prior art, the present invention has the following advantages:

[0052] The present invention provides an analytical modeling method for electromagnetic voltage transformer turn-to-turn short-circuit faults. The method inputs electromagnetic voltage transformer parameters, establishes a simplified finite element turn-to-turn short-circuit fault model of the electromagnetic voltage transformer using a winding grouping method, and proposes an analytical modeling method for the electromagnetic voltage transformer's external impedance based on the finite element analysis results. By employing a technique suitable for winding grouping, the method quantitatively calculates the voltage and current of the electromagnetic voltage transformer's primary and secondary windings under different positions, short-circuit turns ratios, and transition resistance operating modes, with minimal error compared to finite element simulation results. This method provides a theoretical basis for studying the external characteristics of machine-side electromagnetic voltage transformer turn-to-turn short-circuit faults. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a flow chart of the present invention;

[0054] Figure 2 It is the magnetization curve of the electromagnetic voltage transformer core and the winding structure parameters (length, width, height);

[0055] Figure 3 It is a simplified finite element model of electromagnetic voltage transformer applicable to winding grouping technology;

[0056] Figure 4It is the equivalent circuit diagram of the short circuit between the turns of the i-th group and the j-th group of the electromagnetic voltage transformer.

[0057] Figure 5 The present invention also provides a schematic diagram of an electromagnetic voltage transformer turn-to-turn short-circuit fault analysis modeling system.

[0058] Figure 6 The present invention also provides a schematic diagram of an electronic device. DETAILED DESCRIPTION

[0059] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0060] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0061] like Figure 1 As shown, the present invention proposes a method for analyzing and modeling an electromagnetic voltage transformer turn-to-turn short-circuit fault, comprising:

[0062] Get the parameters of electromagnetic voltage transformer;

[0063] Based on the winding grouping method and the parameters, a finite element simulation of the electromagnetic voltage transformer is performed using a transient collaborative simulation method to establish a finite element turn-to-turn short-circuit fault model of the electromagnetic voltage transformer; the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has an turn-to-turn short-circuit are calculated;

[0064] Based on the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has an inter-turn short circuit, an analytical model for the inter-turn short circuit fault of the electromagnetic voltage transformer is established. The voltage and current of the primary and secondary windings of the electromagnetic voltage transformer are analytically calculated under different positions, different short-circuit turns ratios, and different transition resistance operating modes.

[0065] Based on the winding grouping technology, a finite element turn-to-turn short-circuit fault model for an electromagnetic voltage transformer is established to calculate the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has an inter-turn short-circuit. Based on this, the present invention establishes an analytical model for the electromagnetic voltage transformer's inter-turn short-circuit fault applicable to different operating modes, and provides an analytical expression Zp for the impedance outside the complex frequency domain during an inter-turn short-circuit fault. The main innovation lies in the introduction of the winding grouping technology, which can quantitatively calculate the voltage and current of the primary and secondary windings of the electromagnetic voltage transformer under different positions, different short-circuit turns ratios, and different transition resistance operating modes, with a smaller error than the finite element simulation results.

[0066] The principle of the present invention is:

[0067] First, the parameters of the electromagnetic voltage transformer to be analyzed, such as the grid-connected rated voltage, the number of primary winding groups, the transition resistance, and the fault location, are input; then, a finite element short-circuit fault model of the electromagnetic voltage transformer is established. In view of the difficulty that the electromagnetic voltage transformer has a large number of primary winding turns and cannot be directly modeled, a winding grouping modeling method is proposed to calculate the self-inductance and mutual inductance parameters of the primary and secondary windings; finally, based on the calculation results of the finite element short-circuit fault model of the electromagnetic voltage transformer, an electromagnetic voltage transformer short-circuit fault analytical modeling method suitable for winding grouping technology is proposed; the present invention can realize the analytical calculation of the voltage and current of the primary and secondary windings of the electromagnetic voltage transformer in the turn-to-turn short-circuit fault mode; when using the method described in the present invention, the voltage and current of the primary and secondary windings of the electromagnetic voltage transformer can be quantitatively given under different positions, different short-circuit turns ratios, and different transition resistance operating modes, and the error is smaller than that of the finite element simulation results.

[0068] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0069] like Figure 1 As shown, a method for analyzing and modeling the inter-turn short-circuit fault of an electromagnetic voltage transformer is provided. A finite element short-circuit fault model of an electromagnetic voltage transformer suitable for winding grouping technology is established, and an electromagnetic voltage transformer short-circuit fault analysis model is established based on the finite element short-circuit fault model of the electromagnetic voltage transformer. The method includes the following steps:

[0070] Step 1: Input the electromagnetic voltage transformer grid-connected voltage, number of primary winding groups, transition resistance, fault location and other parameters;

[0071] Obtain the following parameters of the electromagnetic voltage transformer: electromagnetic voltage transformer grid-connected rated voltage V1, rated power frequency f, voltage ratio K u , voltage transformer core magnetization curve and winding structure parameters (length, width, height), primary winding grouping number n, transition resistance r, and fault location.

[0072] Step 2: Establish a simplified finite element turn-to-turn short-circuit fault model of the electromagnetic voltage transformer;

[0073] The structure of an electromagnetic voltage transformer is different from that of a power transformer. The primary winding of a transformer usually has dozens to hundreds of turns, while the primary winding of an electromagnetic voltage transformer usually consists of a group of coils with tens of thousands of turns connected in series. The number of turns is too large, and if it is modeled as a power transformer, the simulation calculation will not converge.

[0074] This paper proposes a winding grouping method, specifically dividing a winding consisting of a group of series-connected coils into multiple series-connected concentric cylindrical structures. Each concentric cylindrical structure is equivalent to a multi-turn winding, and the gap between each concentric cylindrical structure is the average of the sum of the gaps in the multi-turn winding. This method is used to establish a simplified finite element short-circuit fault model of an electromagnetic voltage transformer, including an excitation power supply, transition resistors, and the connecting circuits between each winding group. Finite element simulation of the electromagnetic voltage transformer is then performed using transient co-simulation technology.

[0075] Step 3: Derive the electromagnetic voltage transformer short-circuit fault analysis model;

[0076] The turns between the i-th and j-th groups of the electromagnetic voltage transformer are short-circuited. According to Kirchhoff's current law:

[0077] i m1 =i r +i i (1)

[0078] Where i m1 is the grounding primary winding inlet current of the electromagnetic voltage transformer, i r is the fault current flowing through the transition resistor, i i Divert the fault current flowing through the fault winding.

[0079] The fault current splitting expression of the fault winding circuit is:

[0080] i i =h·i m1 (2)

[0081] in:

[0082]

[0083]

[0084] R 1×(j-i+1) =[R i R i+1 … R j ],

[0085] M1 mn is the matrix M1 (j-i+1)×(i-1) Elements in M2mn is the matrix M2 (j-i+1)×(n-j) Elements in M3 mn is the matrix M3 (n-i+1)×(n-i+1) The elements in R 1m is the matrix R 1×(j-i+1) When the turns between the first end of the i-th group and the end of the j-th group of the electromagnetic voltage transformer are short-circuited, the primary current i and the current i flowing through each winding are i The expression between them is:

[0086] i i =V (n+1)2 ·i (3)

[0087] in:

[0088]

[0089] According to equations (1), (2), and (3), the analytical model of the electromagnetic voltage transformer with inter-turn short circuit between the head end of group i and the end end of group j can be obtained:

[0090] u 21 =Z p ·i 21 =A 2(n+1) ·Z (n+1)(n+1) ·V (n+1)2 ·i 21 (4)

[0091] in:

[0092] As can be seen, the above equation describes the analytical model for an electromagnetic voltage transformer turn-to-turn short-circuit fault. This model quantitatively calculates the voltage and current of the primary and secondary windings of an electromagnetic voltage transformer under different operating conditions, with different short-circuit turns ratios, and with different transition resistances. The analytical expression for the impedance outside the complex frequency domain during a turn-to-turn short-circuit fault is Zp, as shown in Equation (4).

[0093] Example

[0094] In order to verify the correctness of the above formula, simulation verification was carried out according to the following parameters:

[0095] First, input the electromagnetic voltage transformer grid-connected rated voltage V1=13.2791kV, rated power frequency f=50Hz, voltage ratio K u :230、Magnetic voltage transformer core magnetization curve and winding structure parameters (length, width, height), such as Figure 2 As shown, the number of primary winding groups n = 46, the transition resistance r = 1 kΩ, and the fault location is the inter-turn short circuit between the 21st to 24th groups of the electromagnetic voltage transformer.

[0096] Then go to step 2 and use the input parameters to build a simplified finite element model of the electromagnetic voltage transformer, such as Figure 3 As shown in the figure, the finite element simulation of the electromagnetic voltage transformer is performed through transient collaborative simulation technology. It can be calculated that the self-inductance and mutual inductance of each winding of the primary winding are 131.1648H, the mutual inductance between the primary winding and the secondary winding is 26.2281H, and the self-inductance of the secondary winding is 9.0860H.

[0097] The modeling method enters step 3, and formula (4) can be obtained:

[0098]

[0099] Based on the finite element self-inductance and mutual inductance calculation results, the 21st to 24th groups of electromagnetic voltage transformers are short-circuited through 1kΩ transition resistors. The primary current i can be obtained from formula (5): m1 The effective value is 0.0708A.

[0100] Finite element simulation of electromagnetic voltage transformer is carried out under the same fault condition. The primary current i m1 The finite element simulation value is 0.0706A, with a relative error of 0.28%. The simulation value is consistent with the analytical calculation value.

[0101] The verification results of the electromagnetic voltage transformer analytical model under some other fault modes are shown in Table 1.

[0102] Table 1 Comparison of some numerical values between analytical model and finite element model

[0103]

[0104] In summary, for an electromagnetic voltage transformer with determined parameters, the voltage and current of the primary and secondary windings of the electromagnetic voltage transformer can be quantitatively given by formula (4), and the error is smaller than that of the finite element simulation results.

[0105] like Figure 5 As shown, the present invention also provides an electromagnetic voltage transformer turn-to-turn short-circuit fault analysis and modeling system, comprising:

[0106] A parameter acquisition module is used to obtain parameters of an electromagnetic voltage transformer;

[0107] A fault model establishment module is used to perform finite element simulation on the electromagnetic voltage transformer through a transient collaborative simulation method based on the winding grouping method and the parameters, establish a finite element turn-to-turn short-circuit fault model of the electromagnetic voltage transformer, and calculate the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has an inter-turn short circuit;

[0108] The analytical model establishment module is used to establish an analytical model for electromagnetic voltage transformer turn-to-turn short-circuit faults based on the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has a turn-to-turn short-circuit. It also analytically calculates the voltage and current of the primary and secondary windings of the electromagnetic voltage transformer under different positions, different short-circuit turns ratios, and different transition resistance operating modes.

[0109] In the analytical model establishment module, the electromagnetic voltage transformer turn-to-turn short-circuit fault analytical model is a complex frequency domain impedance model when the electromagnetic voltage transformer turns are short-circuited. The specific expression of the complex frequency domain impedance model when the turns between the i-th group and the j-th group of the electromagnetic voltage transformer are short-circuited is:

[0110] u 21 =Z p ·i 21 =A 2(n+1) ·Z (n+1)(n+1) ·V (n+1)2 ·i 21

[0111] in:

[0112]

[0113]

[0114]

[0115] M1 mn is the matrix M1 (j-i+1)×(i-1) Elements in M2 mn is the matrix M2 (j-i+1)×(n-j) Elements in M3 mn is the matrix M3 (n-i+1)×(n-i+1) The elements in R 1m is the matrix R 1×(j-i+1) The element in , r is the transition resistance.

[0116] like Figure 6 As shown, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the electromagnetic voltage transformer inter-turn short circuit fault analysis modeling method are implemented.

[0117] The electromagnetic voltage transformer turn-to-turn short-circuit fault analytical modeling method comprises the following steps:

[0118] Get the parameters of electromagnetic voltage transformer;

[0119] Based on the winding grouping method and the parameters, a finite element simulation of the electromagnetic voltage transformer is performed using a transient collaborative simulation method to establish a finite element turn-to-turn short-circuit fault model of the electromagnetic voltage transformer; the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has an turn-to-turn short-circuit are calculated;

[0120] Based on the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has an inter-turn short circuit, an analytical model for the inter-turn short circuit fault of the electromagnetic voltage transformer is established. The voltage and current of the primary and secondary windings of the electromagnetic voltage transformer are analytically calculated under different positions, different short-circuit turns ratios, and different transition resistance operating modes.

[0121] The present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the steps of the electromagnetic voltage transformer inter-turn short circuit fault analysis modeling method.

[0122] The electromagnetic voltage transformer turn-to-turn short-circuit fault analytical modeling method comprises the following steps:

[0123] Get the parameters of electromagnetic voltage transformer;

[0124] Based on the winding grouping method and the parameters, a finite element simulation of the electromagnetic voltage transformer is performed using a transient collaborative simulation method to establish a finite element turn-to-turn short-circuit fault model of the electromagnetic voltage transformer; the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has an turn-to-turn short-circuit are calculated;

[0125] Based on the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has an inter-turn short circuit, an analytical model for the inter-turn short circuit fault of the electromagnetic voltage transformer is established. The voltage and current of the primary and secondary windings of the electromagnetic voltage transformer are analytically calculated under different positions, different short-circuit turns ratios, and different transition resistance operating modes.

[0126] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0127] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0128] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0129] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0130] 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 it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for analyzing and modeling an electromagnetic voltage transformer turn-to-turn short-circuit fault, characterized in that: include: Get the parameters of electromagnetic voltage transformer; Based on the winding grouping method and the parameters, a finite element simulation of the electromagnetic voltage transformer is performed using a transient collaborative simulation method to establish a finite element turn-to-turn short-circuit fault model of the electromagnetic voltage transformer; Calculate the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has a short circuit between turns; Based on the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has an inter-turn short circuit, an analytical model for electromagnetic voltage transformer inter-turn short circuit fault is established. The voltage and current of the primary and secondary windings of the electromagnetic voltage transformer are analytically calculated under different positions, different short-circuit turns ratios, and different transition resistance operating modes. The method of performing finite element simulation on the electromagnetic voltage transformer by using a transient collaborative simulation method based on the winding grouping method includes: A winding consisting of a group of series coils is divided into multiple series concentric cylindrical structures. Each concentric cylindrical structure is equivalent to a multi-turn winding, and the gap between each two concentric cylinders is the average of the sum of the gaps of the multi-turn windings. Based on this, a simplified finite element short-circuit fault model of an electromagnetic voltage transformer is established, which includes an excitation power supply, a transition resistor, and a connection circuit between each winding group. Finite element simulation of the electromagnetic voltage transformer is performed using a transient collaborative simulation method.

2. The electromagnetic voltage transformer turn-to-turn short-circuit fault analytical modeling method according to claim 1, characterized in that: The parameters of the electromagnetic voltage transformer are: electromagnetic voltage transformer grid-connected rated voltage V1, rated power frequency f, voltage ratio K u , voltage transformer core magnetization curve and winding structure parameters, primary winding grouping number n, transition resistance r, and fault location.

3. The method for analyzing and modeling an electromagnetic voltage transformer turn-to-turn short-circuit fault according to claim 2, wherein: The winding structure parameters include the length, width and height of the winding structure.

4. The method for analyzing and modeling an electromagnetic voltage transformer turn-to-turn short-circuit fault according to claim 1, wherein: The electromagnetic voltage transformer turn-to-turn short-circuit fault analytical model is a complex frequency domain impedance model when the electromagnetic voltage transformer turns are short-circuited. The specific expression of the complex frequency domain impedance model when the turns between the i-th group and the j-th group of the electromagnetic voltage transformer are short-circuited is: u 21 =Z p ·i 21 =A 2(n+1) ·Z (n+1)(n+1) ·V (n+1)2 ·i 21 in: R 1×(j-i+1) =[R i R i+1 ··· R j ], M1 mn is the matrix M1 (j-i+1)×(i-1) Elements in M2 mn is the matrix M2 (j-i+1)×(n-j) Elements in M3 mn is the matrix M3 (n-i+1)×(n-i+1) The elements in R 1m is the matrix R 1×(j-i+1) The element in , r is the transition resistance.

5. The electromagnetic voltage transformer turn-to-turn short-circuit fault analytical modeling method according to claim 4, characterized in that: The method of establishing an electromagnetic voltage transformer turn-to-turn short-circuit fault analysis model based on the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer turns are short-circuited specifically includes: The turns between the i-th and j-th groups of the electromagnetic voltage transformer are short-circuited. According to Kirchhoff's current law: i m1 =i r +i i (1) Where i m1 is the grounding primary winding inlet current of the electromagnetic voltage transformer, i r is the fault current flowing through the transition resistor, i i Divert the fault current flowing through the fault winding; The fault current splitting expression of the fault winding circuit is: i i =h·i m1 (2) in: R 1×(j-i+1) =[R i R i+1 ··· R j ], M1 mn is the matrix M1 (j-i+1)×(i-1) Elements in M2 mn is the matrix M2 (j-i+1)×(n-j) Elements in M3 mn is the matrix M3 (n-i+1)×(n-i+1) The elements in R 1m is the matrix R 1×(j-i+1) The element in , r is the transition resistance; When the turns between the first end of the i-th group and the end of the j-th group of the electromagnetic voltage transformer are short-circuited, the primary current i and the current i flowing through each winding are i The expression between them is: and i =V (n+1)2 ·i (3) in: i=[i1 ··· i i-1 i i i i+1 ··· i n i n+1 ] T , According to equations (1), (2), and (3), the analytical model of the electromagnetic voltage transformer with inter-turn short circuit between the head end of group i and the end end of group j is obtained: u 21 =Z p ·i 21 =A 2(n+1) ·Z (n+1)(n+1) ·V (n+1)2 ·i 21 (4) in:

6. A system for analyzing and modeling electromagnetic voltage transformer turn-to-turn short-circuit faults, characterized in that: include: A parameter acquisition module is used to obtain parameters of an electromagnetic voltage transformer; A fault model establishment module is used to perform finite element simulation on the electromagnetic voltage transformer through a transient collaborative simulation method based on the winding grouping method and the parameters, and establish a finite element turn-to-turn short-circuit fault model of the electromagnetic voltage transformer; Calculate the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has a short circuit between turns; The analytical model building module is used to establish an analytical model for electromagnetic voltage transformer turn-to-turn short-circuit faults based on the self-inductance of each winding and the mutual inductance between windings when the electromagnetic voltage transformer has a turn-to-turn short-circuit. It also analytically calculates the voltage and current of the primary and secondary windings of the electromagnetic voltage transformer under different positions, different short-circuit turns ratios, and different transition resistance operating modes. The method of performing finite element simulation on the electromagnetic voltage transformer by using a transient collaborative simulation method based on the winding grouping method includes: A winding consisting of a group of series coils is divided into multiple series concentric cylindrical structures. Each concentric cylindrical structure is equivalent to a multi-turn winding, and the gap between each two concentric cylinders is the average of the sum of the gaps of the multi-turn windings. Based on this, a simplified finite element short-circuit fault model of an electromagnetic voltage transformer is established, which includes an excitation power supply, a transition resistor, and a connection circuit between each winding group. Finite element simulation of the electromagnetic voltage transformer is performed using a transient collaborative simulation method.

7. The electromagnetic voltage transformer turn-to-turn short-circuit fault analysis and modeling system according to claim 6, characterized in that: In the analytical model establishment module, the electromagnetic voltage transformer turn-to-turn short-circuit fault analytical model is a complex frequency domain impedance model when the electromagnetic voltage transformer turns are short-circuited. The specific expression of the complex frequency domain impedance model when the turns between the i-th group and the j-th group of the electromagnetic voltage transformer are short-circuited is: u 21 =Z p ·i 21 =A 2(n+1) ·Z (n+1)(n+1) ·V (n+1)2 ·i 21 in: R 1×(j-i+1) =[R i R i+1 ··· R j ], M1 mn is the matrix M1 (j-i+1)×(i-1) Elements in M2 mn is the matrix M2 (j-i+1)×(n-j) Elements in M3 mn is the matrix M3 (n-i+1)×(n-i+1) The elements in R 1m is the matrix R 1×(j-i+1) The element in , r is the transition resistance.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the electromagnetic voltage transformer turn-to-turn short-circuit fault analysis modeling method according to any one of claims 1 to 5 are implemented.

9. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the computer program implements the steps of the electromagnetic voltage transformer inter-turn short circuit fault analysis modeling method according to any one of claims 1 to 5.

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