CN114706012A - Method and device for calculating grounding current of transformer and storage medium - Google Patents
Method and device for calculating grounding current of transformer and storage medium Download PDFInfo
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Abstract
The invention discloses a method, equipment and a storage medium for calculating grounding current of a transformer, wherein a geometric structure model for representing the structural characteristics of each metal structural part is established, an electrostatic field finite element model is established according to the geometric structure model, the electrostatic field characteristics of the transformer can be quickly obtained, a partial capacitance matrix is obtained according to the electrostatic field finite element model, a circuit simulation model corresponding to the transformer, namely an equivalent circuit of the transformer, can be obtained according to the partial capacitance matrix, and the grounding current of the transformer can be quickly and accurately calculated through the circuit simulation model; in conclusion, the method and the device can simplify the calculation process of the grounding current of the transformer and improve the calculation precision of the grounding current of the transformer.
Description
Technical Field
The invention relates to the technical field of electricity, in particular to a method and equipment for calculating grounding current of a transformer and a storage medium.
Background
When the transformer operates, the winding and the lead wire with high potential generate suspension potential to the ground through the electromagnetic coupling relationship of the iron core, the clamping piece and other metal structural members, and suspension discharge can be caused. In order to avoid the occurrence of suspension discharge, the transformer core and the clamping piece are led out to the outside of the transformer oil tank through a small sleeve by a special grounding point and are grounded at one point.
The capacitance values of the transformer winding to the iron core and the clamping piece can be measured when a factory test is carried out on the transformer, but the measurement condition is that the winding is an equal potential, and each turn of the winding has a certain induced potential instead of the equal potential in the actual operation process of the transformer, so that the measurement capacitors cannot be directly applied when the grounding current of the transformer is calculated in the related technology, but certain assumptions need to be made, and the calculation process of the grounding current of the transformer is complex and the calculation accuracy is low.
Disclosure of Invention
In view of this, the present invention provides a method, a device and a storage medium for calculating a transformer ground current, which are used to solve the problems of complex calculation process and low calculation accuracy of the transformer ground current in the prior art. To achieve one or a part or all of the above or other objects, the following embodiments are provided:
the embodiment of the first aspect of the invention provides a method for calculating grounding current of a transformer, wherein the transformer comprises a plurality of metal structural parts, and the method comprises the following steps: establishing a geometric structure model, wherein the geometric structure model is used for representing the structural characteristics of each metal structural part; establishing an electrostatic field finite element model according to the geometric structure model, and obtaining a partial capacitance matrix according to the electrostatic field finite element model, wherein the partial capacitance matrix is used for representing partial capacitance corresponding to each metal structural part; and establishing a circuit simulation model according to the partial capacitance matrix so as to determine the grounding current according to the circuit simulation model.
Preferably, the establishing of the geometric structure model includes: establishing an initial geometric model, wherein the initial geometric model is used for representing the geometric structure of each metal structural part; and carrying out simplified segmentation processing on the initial geometric model to obtain the geometric structure model.
Preferably, the metal structural members comprise windings, and the initial geometric model comprises a structural sub-model of each of the metal structural members; the simplified segmentation processing on the initial geometric model to obtain the geometric structure model comprises: simplifying the structural submodel of the winding into a cylindrical conductor model; and carrying out segmentation processing on the cylindrical conductor model to obtain the three-dimensional structure model, wherein the three-dimensional structure model comprises the cylindrical conductor model which is subjected to the segmentation processing.
Preferably, establishing an electrostatic field finite element model according to the geometric structure model, and obtaining a partial capacitance matrix according to the electrostatic field finite element model, includes: importing the geometric structure model into electric field analysis finite element software to carry out electrostatic field calculation to obtain an electrostatic field calculation result; obtaining a static induction coefficient matrix according to the electrostatic field calculation result, wherein the static induction coefficient matrix is used for representing the static induction coefficient of each metal structural part; and obtaining the partial capacitance matrix according to the static induction coefficient matrix.
Preferably, the step of introducing the geometric structure model into electric field analysis finite element software to perform electrostatic field calculation to obtain an electrostatic field calculation result includes: importing the geometric structure model into electric field analysis finite element software, and setting material properties and boundary conditions corresponding to the geometric structure model through the electric field analysis finite element software; and performing electrostatic field calculation through the electric field analysis finite element software according to the geometric structure model, the material property and the boundary condition to obtain an electrostatic field calculation result.
Preferably, the establishing a circuit simulation model according to the partial capacitance matrix to determine the ground current according to the circuit simulation model includes: inputting the partial capacitance matrix into circuit simulation software to establish the circuit simulation model; and determining the grounding current according to the circuit simulation model through the circuit simulation software.
Preferably, the determining the grounding current according to the circuit simulation model by the circuit simulation software comprises setting working condition parameters of the circuit simulation model by the circuit simulation software, wherein the working condition parameters are used for representing the working conditions of the metal structural members; and determining the grounding current according to the circuit simulation model and the working condition parameters through the circuit simulation software.
Preferably, the embodiment of the present invention further includes: and judging whether the metal structural part is in a normal grounding state or not according to the grounding current and an actual measurement result, wherein the actual measurement result is used for representing the current between the actual transformer and the ground, which is obtained by measuring the actual transformer on site, and the actual transformer corresponds to the geometric structure model.
An embodiment of a second aspect of the present invention provides an apparatus, including: the present invention relates to a transformer ground current calculation method, and a computer program stored on a memory and executable on a processor.
In an embodiment of the third aspect of the present invention, a computer-readable storage medium is provided, which stores computer-executable instructions for performing a method for calculating a transformer ground current according to any one of the embodiments of the first aspect of the present invention.
The embodiment of the invention has the following beneficial effects:
according to the method, the device and the storage medium for calculating the grounding current of the transformer, disclosed by the embodiment of the invention, the geometric structure model for representing the structural characteristics of each metal structural part is established, the electrostatic field finite element model is established according to the geometric structure model, the electrostatic field characteristics of the transformer can be quickly obtained, then the partial capacitance matrix is obtained according to the electrostatic field finite element model, the circuit simulation model corresponding to the transformer, namely the equivalent circuit of the transformer, can be obtained according to the partial capacitance matrix, and the grounding current of the transformer can be quickly and accurately calculated through the circuit simulation model; in summary, the embodiment of the invention can simplify the calculation process of the grounding current of the transformer and can improve the calculation precision of the grounding current of the transformer.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Wherein:
FIG. 1 is a schematic diagram of a ground current equivalent circuit in the related art;
FIG. 2 is a schematic diagram of another equivalent circuit of ground current in the related art;
fig. 3 is an equivalent circuit diagram of a winding provided by an embodiment of the present invention;
FIG. 4 is another equivalent circuit diagram of a winding provided by an embodiment of the present invention;
fig. 5 is a flowchart of a method for calculating a ground current of a transformer according to an embodiment of the present invention;
fig. 6 is a flowchart of a method for calculating a grounding current of a transformer according to another embodiment of the present invention;
fig. 7 is a flowchart of a method for calculating a grounding current of a transformer according to another embodiment of the present invention;
fig. 8 is a flowchart of a method for calculating a grounding current of a transformer according to another embodiment of the present invention;
fig. 9 is a flowchart of a method for calculating a grounding current of a transformer according to another embodiment of the present invention;
fig. 10 is a flowchart of a method for calculating a grounding current of a transformer according to another embodiment of the present invention;
fig. 11 is a flowchart of a method for calculating a grounding current of a transformer according to another embodiment of the present invention;
FIG. 12 is a schematic diagram of a transformer according to an embodiment of the present invention;
fig. 13 is a schematic diagram of a winding segmentation process according to an embodiment of the present invention;
FIG. 14 is a schematic diagram of an equivalent circuit provided in accordance with an embodiment of the present invention;
fig. 15 is a schematic diagram of an apparatus according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
It should be noted that although functional blocks are partitioned in a schematic diagram of an apparatus and a logical order is shown in a flowchart, in some cases, the steps shown or described may be performed in a different order than the partitioning of blocks in the apparatus or the order in the flowchart. The terms first, second and the like in the description and in the claims, and the drawings described above, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.
The invention provides a method, equipment and a storage medium for calculating the grounding current of a transformer, wherein the method for calculating the grounding current of the transformer comprises the following steps of: establishing a geometric structure model, wherein the geometric structure model is used for representing the structural characteristics of each metal structural part; establishing an electrostatic field finite element model according to the geometric structure model, and obtaining a partial capacitance matrix according to the electrostatic field finite element model, wherein the partial capacitance matrix is used for representing partial capacitance corresponding to each metal structural part; and establishing a circuit simulation model according to the partial capacitance matrix so as to determine the grounding current according to the circuit simulation model. The method comprises the steps of establishing a geometric structure model for representing the structural characteristics of each metal structural part, establishing an electrostatic field finite element model according to the geometric structure model, quickly obtaining the electrostatic field characteristics of the transformer, obtaining a partial capacitance matrix according to the electrostatic field finite element model, obtaining a circuit simulation model corresponding to the transformer according to the partial capacitance matrix, namely an equivalent circuit of the transformer, and quickly and accurately calculating the grounding current of the transformer through the circuit simulation model; in summary, the embodiment of the invention can simplify the calculation process of the grounding current of the transformer and can improve the calculation precision of the grounding current of the transformer.
The embodiments of the present invention will be further explained with reference to the drawings.
When the transformer operates, the winding and the lead wire with high potential generate suspension potential to the ground through the electromagnetic coupling relationship of the iron core, the clamping piece and other metal structural members, and suspension discharge can be caused. In order to avoid the occurrence of suspension discharge, the transformer core and the clamping piece are led out to the outside of the transformer oil tank through a small sleeve by a special grounding point and are grounded at one point.
The high potential electrodes such as transformer coils and lead wires are in resistance and capacitance coupling relation with the low potential electrodes such as iron cores and structural members. An equivalent circuit of the grounding current of the structural member is described by taking a single-phase transformer as an example, as shown in fig. 1, wherein R is mainly an insulation resistance between a high-potential electrode and the structural member, and C is a distributed capacitance between the high-potential electrode and the structural member. Grounding current I when the transformer is runninggndCan be expressed by the following formula.
From the above formula, the magnitude of the structure ground current is related to the voltage difference U between the two electrodes, the angular frequency ω, the capacitance C, and the insulation resistance R. For a three-phase transformer, grounding currents of an iron core and a clamping piece are equal to the sum of three-phase currents, and when three-phase insulation resistance and distributed capacitance are completely consistent, IgndEqual to 0, which results in the generation of ground currents, since the insulation resistance and distributed capacitance parameters between the three-phase transformers cannot be completely identical. Therefore, the grounding current of the iron core and the clamp of the three-phase transformer is mainly determined by the voltage and the frequency of the winding and the insulation resistance and the size and the consistency of the capacitance between the winding and the iron core. The higher the voltage and the frequency, the larger the grounding current is; the smaller the insulation resistance and the larger the capacitance, the larger the grounding current is; the worse the consistency of the three-phase insulation resistance and the capacitance, the larger the grounding current.
In order to shield sharp corners of the core leg of the transformer, the transformer is usually designed with an electrostatic shielding measure, i.e. a ground shield, on the outer surface of the core leg. If the ground screen is led to the clamping piece through the lead wire and grounded together with the clamping piece and the like, the iron core is shielded by metal formed by the ground screen, the clamping piece and the like, the resistive current and the capacitive current transmitted by high-potential conductors such as a winding, the lead wire and the like are very small, and the grounding current of the iron core is far smaller than the grounding current of the clamping piece; if the ground screen is connected with the iron core, the grounding current of the iron core is much larger than that of the clamping piece. Meanwhile, the capacitance between the inner winding near the core side and the ground shield is the largest, and the insulation resistance is the smallest, so as shown in fig. 2, the grounding current in this case mainly depends on the voltage of the inner winding near the core side and the capacitance and insulation resistance between the inner winding and the ground shield.
The iron core of the transformer is easily grounded at multiple points due to common iron precipitates in oil, vibration, the structure of the transformer and the like, if the iron core and the clamping piece have another grounding point due to some reason, a closed loop is formed, and the circulating current sometimes can reach dozens of amperes or even hundreds of amperes, so that the iron core or the clamping piece is locally short-circuited and overheated. If not discovered in time, core burnout can cause local heating of the core or arc grounding points. The purpose of monitoring the grounding current of the transformer core and the clamping piece is to prevent and limit the damage caused by multipoint grounding of the transformer core and the clamping piece.
According to DL/T596-. The above requirements are empirical values provided based on the existing engineering experience, however, the structure of the transformer varies, the application of new design materials is endless, and the limit value based on the experience cannot meet the actual requirements.
The transformer and the application scenario described above are for more clearly illustrating the technical solution of the embodiment of the present invention, and do not constitute a limitation to the technical solution provided by the embodiment of the present invention, and it is known to those skilled in the art that the technical solution provided by the embodiment of the present invention is also applicable to similar technical problems with the evolution of the transformer and the appearance of new application scenarios.
As shown in fig. 3, fig. 3 is an equivalent circuit diagram of a winding according to an embodiment of the present invention. The factory test of the transformer measures the capacitance of each winding, for example, in the example of fig. 1, for a single-phase two-winding transformer, the low-voltage winding, the oil tank and other structural members are grounded, and the equivalent capacitance C of the high-voltage winding to the ground is measured11. Grounding the high-voltage winding, the oil tank and other structural members, and measuring the equivalent capacitance C of the low-voltage winding to the ground22. Grounding the oil tank and other structural members, and measuring the equivalent capacitance C of the high-voltage winding to the low-voltage winding12. Partial capacitance can be calculated by the above 3 equivalent capacitances, and an equivalent circuit shown in fig. 3 is obtained.
However, referring to fig. 4, fig. 4 is another equivalent circuit diagram of the winding provided by the embodiment of the present invention, in the example of fig. 4, the core and the clip of the transformer are actually respectively led out to the ground, i.e. the equivalent circuit has 4 electrodes, and obviously, the equivalent circuit of fig. 3 has no way to separate the grounding currents of the core and the clip.
In order to solve the above problems, embodiments of the present invention provide a method for calculating a ground current of a transformer, which can simplify a calculation process on the premise of ensuring calculation accuracy and separating respective ground currents of an iron core and a clamp.
It will be appreciated by persons skilled in the art that the equivalent circuits shown in figures 1 to 4 do not constitute limitations on embodiments of the invention, and that they may comprise more or less components than those shown, or some components may be combined, or a different arrangement of components.
As shown in fig. 5, fig. 5 is a flowchart of a method for calculating a ground current of a transformer according to an embodiment of the present invention, and in the example of fig. 5, the method for calculating a ground current of a transformer according to an embodiment of the present invention includes, but is not limited to, step S100, step S200, and step S300;
s100, obtaining a geometric structure model, wherein the geometric structure model is used for representing the structural characteristics of each metal structural part;
step S200, establishing an electrostatic field finite element model according to the geometric structure model, and obtaining a partial capacitance matrix according to the electrostatic field finite element model, wherein the partial capacitance matrix is used for representing partial capacitance corresponding to each metal structural part;
and step S300, establishing a circuit simulation model according to the partial capacitance matrix so as to determine the grounding current according to the circuit simulation model.
According to the scheme provided by the embodiment of the invention, the geometric structure model used for representing the structural characteristics of each metal structural part is established, the electrostatic field finite element model is established according to the geometric structure model, the electrostatic field characteristic of the transformer can be quickly obtained, the partial capacitance matrix is obtained according to the electrostatic field finite element model, the circuit simulation model corresponding to the transformer, namely the equivalent circuit of the transformer, can be obtained according to the partial capacitance matrix, and the grounding current of the transformer can be quickly and accurately calculated through the circuit simulation model; in summary, the embodiment of the invention can simplify the calculation process of the grounding current of the transformer and can improve the calculation precision of the grounding current of the transformer.
As shown in fig. 6, the above method step S100 includes, but is not limited to, step S110 and step S120:
step S110, establishing an initial geometric model, wherein the initial geometric model is used for representing the geometric structure of each metal structural part;
and step S120, carrying out simplified segmentation processing on the initial geometric model to obtain a geometric structure model.
In one embodiment, the metallic structural components of the transformer include, but are not limited to, windings, cores, core shields, clamps, and tanks.
In one embodiment, the initial geometric model includes a structural sub-model of each metallic structural member.
Specifically, the geometric structure model does not include structural submodels of all metal structural members of the transformer, but only includes metal structural members such as windings, iron cores, iron core ground screens, clamping pieces and oil tanks which have a large influence on capacitance calculation, so that the demand on calculation force is reduced on the premise of ensuring calculation accuracy, and the calculation process is simplified.
It should be noted that, performing simplified segmentation processing on the initial geometric model may include removing a structure sub-model of a metal structure that has a small influence on the capacitance calculation from each structure sub-model included in the original geometric model.
Specifically, the software that can be used for establishing and processing the initial geometric model, the structural submodel and the geometric model includes, but is not limited to, SpaceCliam, Solidworks and Ansys Design Modeler.
As shown in fig. 7, the above method step S120 includes, but is not limited to, step S121 and step S122:
step S121, simplifying the structural submodel of the winding into a cylindrical conductor model;
step S122, performing segmentation processing on the cylindrical conductor model to obtain a three-dimensional structure model, where the three-dimensional structure model includes the cylindrical conductor model that has completed the segmentation processing.
In one embodiment, the transformer winding is simplified, the linear change of the axial potential of the winding can be simplified into a cylindrical conductor when the continuous winding runs, then the cylindrical conductor is segmented along the axial direction, the more the segmentation number is, the more accurate the calculation time is, but the more the calculation resource consumption is, and the more the calculation time is, the more the calculation resource consumption is, the more the calculation precision is, and the more the calculation complexity is not increased by performing segmentation processing on the winding while the calculation precision is improved by obtaining the winding distributed capacitance parameter.
As shown in fig. 8, the above method step S200 includes, but is not limited to, step S210, step S220, and step S230:
step S210, importing the geometric structure model into electric field analysis finite element software to carry out electrostatic field calculation to obtain an electrostatic field calculation result;
step S220, obtaining a static induction coefficient matrix according to the electrostatic field calculation result, wherein the static induction coefficient matrix is used for representing the static induction coefficient of each metal structural part;
and step S230, obtaining a partial capacitance matrix according to the static induction coefficient matrix.
As shown in fig. 9, the above method step S210 includes, but is not limited to, step S211, step S212, and step S213:
step S211, importing the geometric structure model into electric field analysis finite element software, and setting material properties and boundary conditions corresponding to the geometric structure model through the electric field analysis finite element software;
and S212, performing electrostatic field calculation through electric field analysis finite element software according to the geometric structure model, the material properties and the boundary conditions to obtain an electrostatic field calculation result.
Specifically, the geometric structure model is imported into low-frequency electric field analysis finite element software, transformer finite element modeling is carried out, material properties and boundary conditions are set, and specifically: arranging a metal structural part as a conductor, filling insulating oil in an oil tank, and arranging the insulating oil as a medium; and applying independent potential boundary conditions to each metal structural part, wherein the inner wall of the oil tank is used as a calculated boundary. And carrying out electrostatic field calculation after grid division. And deriving a static induction coefficient matrix according to the static field calculation result.
Specifically, available low frequency electric field analysis finite element software includes, but is not limited to, Ansys Emag, Maxwell, and Elecnet.
As shown in fig. 10, the above method step S300 includes, but is not limited to, step S310 and step S320:
step S310, inputting part of the capacitance matrix into circuit simulation software to establish a circuit simulation model;
and step S320, determining the grounding current according to the circuit simulation model through circuit simulation software.
The circuit simulation model is used for calculating the grounding current, working conditions such as different wiring modes, series current limiting resistors and power supply harmonics of all structural parts can be conveniently considered, and multiple working conditions can be calculated through once modeling. The grounding current of the transformer core clamp is conveniently analyzed by operation or maintenance personnel whether to be in a normal state.
As shown in fig. 11, the above method step S320 includes, but is not limited to, step S321 and step S322:
step S321, setting working condition parameters of the circuit simulation model through circuit simulation software, wherein the working condition parameters are used for representing the working conditions of each metal structural part;
step S322, the grounding current is determined according to the circuit simulation model and the working condition parameters through the circuit simulation software.
Specifically, after an equivalent circuit is established, that is, after a circuit simulation model is established, circuit connection can be performed according to the actual transformer wiring, working condition parameters are set according to the actual winding voltage, the working condition parameters include but are not limited to excitation, the grounding current of the iron core and the clamping piece is calculated, and abnormal states such as grounding wire disconnection or multipoint grounding, harmonic voltage and the like can be simulated by changing the wiring and changing the applied excitation.
Specifically, available circuit simulation software includes, but is not limited to, PSCAD, EMTP, and Simulink.
In an embodiment, the embodiment of the present invention further includes, but is not limited to, step S400, and step S400 includes: and judging whether the metal structural part is in a normal grounding state or not according to the grounding current and an actual measurement result, wherein the actual measurement result is used for representing the current between the actual transformer and the ground, which is obtained by measuring the actual transformer on site, and the actual transformer corresponds to the geometric structure model.
In one embodiment, the calculated grounding current is compared with the field actual measurement, so that whether the transformer core and the clamping piece are in a normal single-point grounding state or not can be judged.
Example one:
referring to fig. 12, fig. 12 is a schematic diagram of a transformer according to an embodiment of the present invention, in the example of fig. 12, the single-phase dual-winding transformer is a four-leg type, 2 legs and 2 side legs, and the windings are arranged as an iron core-ground shield-low voltage winding-high voltage winding-voltage regulating winding, and at least metal structural members having a large influence on capacitance calculation, such as each winding, the iron core-ground shield, a clamp, and an oil tank, need to be reserved during modeling.
Referring to fig. 13, fig. 13 is a schematic diagram of the winding segmentation processing provided by a specific example of the present invention, in the example of fig. 13, the transformer winding is simplified, the linear change of the axial potential of the winding during the operation of the continuous winding can be simplified into a cylindrical conductor, and then the cylindrical conductor is segmented axially, the more the number of segments is, the more accurate the calculation time and the calculation resource consumption are, and generally 10 segments can be obtained with acceptable accuracy.
Importing the geometric structure model of the transformer into low-frequency electric field analysis finite element software, carrying out transformer finite element modeling, and setting material properties and boundary conditions, specifically: arranging a metal structural part as a conductor, filling insulating oil in an oil tank, and arranging the insulating oil as a medium; and applying independent potential boundary conditions to each metal structural part, wherein the inner wall of the oil tank is used as a calculated boundary. And carrying out electrostatic field calculation after grid division. Deriving a static induction coefficient matrix beta according to a static field calculation result:
in this example, 25 electrodes were used in total, and the resulting static inductance matrix size was 25 × 25. The electric field calculation software used here is Maxwell.
Calculating a partial capacitance matrix C according to the static induction coefficient matrix:
wherein diagonal elements
Off diagonal element Cn-m＝-βn-m。
Inputting part of capacitance into circuit simulation software to establish an equivalent circuit, for this example, there are 25 terminals in a circuit corresponding to 25 electrodes, referring to fig. 14, fig. 14 is a schematic diagram of the equivalent circuit provided by a specific example of the present invention, and in the example of fig. 14, the parts connected to the terminals are illustrated: k1 corresponds to the folder, k2 corresponds to the iron core, k3 corresponds to the ground screen, k4 corresponds to the oil tank, k 5-k 14 corresponds to the low-voltage winding, wherein k5 is the head end k14 as the tail end, k 15-k 24 correspond to the high-voltage winding, wherein k15 is the head end k24 as the tail end, and k25 corresponds to the voltage-regulating winding. And carrying out circuit connection according to the actual transformer wiring, setting excitation according to the actual voltage of the winding, and calculating the grounding current of the iron core and the clamping piece. Abnormal states such as disconnection of a grounding wire or multipoint grounding, harmonic voltage and the like can be simulated by changing wiring and changing applied excitation. The circuit calculation software used here is EMTP. Finally, the calculated grounding current is compared with the field actual measurement, and whether the transformer core and the clamping piece are in a normal single-point grounding state or not can be judged.
In addition, referring to fig. 15, an embodiment of the present invention further provides an apparatus 100, where the apparatus 100 is provided with a processor 101 and a memory 102, and the processor 101 and the memory 102 are connected through a bus. In particular, the processor 101 is used to provide computing and control capabilities, supporting the operation of the overall device 100. The Processor 101 may be a Central Processing Unit (CPU), and the Processor 101 may also be other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component, etc. Wherein a general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
Specifically, the Memory 102 may be a Flash chip, a Read-Only Memory (ROM) magnetic disk, an optical disk, a usb disk, or a removable hard disk.
It will be understood by those skilled in the art that the structure shown in fig. 15 is a block diagram of only a portion of the structure associated with embodiments of the invention and does not constitute a limitation on the apparatus 100 to which embodiments of the invention may be applied, and that a particular server may include more or fewer components than shown in the figures, or some components may be combined, or have a different arrangement of components.
The processor is configured to run a computer program stored in the memory, and when the computer program is executed, implement any one of the methods for calculating the transformer ground current provided by the embodiments of the present invention.
In an embodiment, the processor is configured to run a computer program stored in the memory.
It should be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working process of the apparatus 100 described above may refer to the corresponding process in the foregoing embodiment of the method for calculating the grounding current of the transformer, and details are not described herein again.
In addition, an embodiment of the present invention further provides a computer-readable storage medium, where one or more programs are stored, and the one or more programs are executable by one or more processors to implement the steps of any method for calculating the transformer ground current provided in the present specification.
The storage medium may be an internal storage unit of the electronic device of the foregoing embodiment, for example, a hard disk or a memory of the electronic device. The storage medium may also be an external storage device of the electronic device, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and the like, provided on the electronic device.
It will be understood by those of ordinary skill in the art that all or some of the steps, systems, and methods disclosed above may be implemented as software, firmware, hardware, or suitable combinations thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as is well known to those of ordinary skill in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.
While the preferred embodiments of the present invention have been described, the present invention is not limited to the above embodiments, and those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and such equivalent modifications or substitutions are to be included within the scope of the present invention defined by the appended claims.
Claims (10)
1. A method for calculating a grounding current of a transformer, the transformer comprising a plurality of metallic structural members, the method comprising:
establishing a geometric structure model, wherein the geometric structure model is used for representing the structural characteristics of each metal structural part;
establishing an electrostatic field finite element model according to the geometric structure model, and obtaining a partial capacitance matrix according to the electrostatic field finite element model, wherein the partial capacitance matrix is used for representing partial capacitance corresponding to each metal structural part;
and establishing a circuit simulation model according to the partial capacitance matrix so as to determine the grounding current according to the circuit simulation model.
2. The method for calculating the grounding current of the transformer according to claim 1, wherein the establishing of the geometric structure model comprises:
establishing an initial geometric model, wherein the initial geometric model is used for representing the geometric structure of each metal structural part;
and carrying out simplified segmentation processing on the initial geometric model to obtain the geometric structure model.
3. The method for calculating the grounding current of the transformer according to claim 2, wherein the metal structural members comprise windings, and the initial geometric model comprises a structural sub-model of each metal structural member;
the simplified segmentation processing on the initial geometric model to obtain the geometric model includes:
simplifying the structural submodel of the winding into a cylindrical conductor model;
and carrying out segmentation processing on the cylindrical conductor model to obtain the three-dimensional structure model, wherein the three-dimensional structure model comprises the cylindrical conductor model which is subjected to the segmentation processing.
4. The method of claim 1, wherein the establishing a finite element model of the electrostatic field according to the geometric model and obtaining a partial capacitance matrix according to the finite element model of the electrostatic field comprises:
importing the geometric structure model into electric field analysis finite element software to carry out electrostatic field calculation to obtain an electrostatic field calculation result;
obtaining a static induction coefficient matrix according to the electrostatic field calculation result, wherein the static induction coefficient matrix is used for representing the static induction coefficient of each metal structural part;
and obtaining the partial capacitance matrix according to the static induction coefficient matrix.
5. The method for calculating the grounding current of the transformer according to claim 4, wherein the step of introducing the geometric structure model into electric field analysis finite element software for electrostatic field calculation to obtain an electrostatic field calculation result comprises:
importing the geometric structure model into electric field analysis finite element software, and setting material properties and boundary conditions corresponding to the geometric structure model through the electric field analysis finite element software;
and performing electrostatic field calculation through the electric field analysis finite element software according to the geometric structure model, the material property and the boundary condition to obtain an electrostatic field calculation result.
6. The method for calculating the grounding current of the transformer according to claim 1, wherein the establishing a circuit simulation model according to the partial capacitance matrix to determine the grounding current according to the circuit simulation model comprises:
inputting the partial capacitance matrix into circuit simulation software to establish the circuit simulation model;
and determining the grounding current according to the circuit simulation model through the circuit simulation software.
7. The method for calculating the grounding current of the transformer according to claim 6, wherein the determining the grounding current according to the circuit simulation model by the circuit simulation software comprises:
setting working condition parameters of the circuit simulation model through the circuit simulation software, wherein the working condition parameters are used for representing the working conditions of the metal structural parts;
and determining the grounding current according to the circuit simulation model and the working condition parameters through the circuit simulation software.
8. The method for calculating the grounding current of the transformer according to claim 1, further comprising: and judging whether the metal structural part is in a normal grounding state or not according to the grounding current and an actual measurement result, wherein the actual measurement result is used for representing the current between the actual transformer and the ground, which is obtained by measuring the actual transformer on site, and the actual transformer corresponds to the geometric structure model.
9. An apparatus, comprising: memory, processor and computer program stored on the memory and executable on the processor, characterized in that the processor implements a method for calculating a transformer ground current according to any one of claims 1 to 8 when executing the computer program.
10. A computer-readable storage medium storing computer-executable instructions for performing the method of calculating the transformer ground current according to any one of claims 1 to 8.
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