CN113190964B - Method for creating saturation model of single-phase four-column transformer - Google Patents
Method for creating saturation model of single-phase four-column transformer Download PDFInfo
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Abstract
The invention discloses a method for creating a transformer saturation model of a single-phase four-column iron core structure, which comprises the following steps: obtaining a voltage-resistance current curve and a voltage-inductance current curve of the excitation branch circuit by utilizing piecewise linearization; establishing a magnetic circuit of which the main flux and the leakage flux of the single-phase four-column transformer are uniformly considered to obtain the relation between the inductance and the magnetic conductance of the iron core, and enabling the single-phase four-column structure to be equivalent to two single-phase three-column structures to obtain the relation between the magnetic conductance of the iron core and the exciting current; calculating exciting current according to the winding current of the primary and secondary sides at the previous moment, judging the position of the exciting current on a voltage-inductance current curve, calculating the magnetic conductance and the inductance of the iron core at the current moment, calculating the winding current of the primary and secondary sides at the next moment by using a backward Euler method, and calculating the loss current flowing through the nonlinear resistor according to the winding voltage and the voltage-resistance current curve at the previous moment to obtain the current of each side of the single-phase four-column transformer. The invention can fully consider the iron core saturation and the iron core loss and has higher analysis efficiency and analysis precision.
Description
Technical Field
The invention relates to the technical field of electromagnetic transient simulation calculation, in particular to a method for creating a saturation model of a single-phase four-column transformer.
Background
With the development of extra-high voltage transmission, the capacity of the extra-high voltage alternating current-direct current transformer is gradually increased. The ultrahigh voltage high-capacity transformer in China generally adopts a single-phase structure, and a three-phase transformer bank is formed by three single phases. Due to the increase of the capacity of the single-phase transformer, the limitation of the transportation size and the requirement of reducing the magnetic density, the ultra-high voltage transformer generally adopts a multi-column parallel structure, such as a single-phase four-column structure consisting of two side columns of two main columns. At present, a model library of common electromagnetic transient simulation software does not contain a single-phase four-column transformer model, so that the problem of large calculation error exists when the characteristics in equipment and an extra-high voltage direct current transmission network are subjected to simulation analysis; in addition, methods such as finite element and field coupling are mostly adopted for modeling of single-phase four-column transformers at present, and although the methods can perform more detailed analysis and have higher precision on the transformers, the modeling is more complex, the calculation speed is not high when a large-scale transformer is simulated, and the methods are not suitable for performing electromagnetic transient simulation on a power network containing the single-phase four-column transformers. Therefore, it is necessary to construct a single-phase four-column transformer saturation model suitable for engineering application.
Disclosure of Invention
The technical problem to be solved by the embodiments of the present invention is to provide a method for creating a saturation model of a single-phase four-limb transformer, which can fully consider core saturation and core loss when analyzing a single-phase four-limb electromagnetic transient, and has higher analysis efficiency and analysis accuracy.
In order to solve the technical problem, an embodiment of the present invention provides a method for creating a saturation model of a single-phase four-column transformer, including:
establishing a magnetic circuit model of the single-phase four-column transformer, and obtaining a standard inductance matrix according to the magnetic circuit model;
obtaining an iron core magnetic conductance model according to a magnetic circuit structure of the single-phase four-column transformer;
obtaining a piecewise linearization magnetic conductance model according to a voltage-resistance current curve, a voltage-inductance current curve, a magnetic flux leakage magnetic conductance and the iron core magnetic conductance model; the leakage magnetic conduction is obtained by load loss, load current and short-circuit impedance measured in a rated load test of the transformer;
calculating the nonlinear inductor current flowing into the nonlinear inductor according to the current of the secondary side winding at the last moment;
judging a linear section where the current flowing into the nonlinear inductor is positioned, and calculating the magnetic conductance of the iron core and an inductance matrix at the moment through the segmented linearized magnetic conductance model and a standard inductance matrix;
and obtaining time domain currents at two ends of the single-phase four-column transformer according to the iron core magnetic conductance, the inductance matrix, the transient model of the transformer port and the nonlinear resistance current.
Further, the method for obtaining the voltage-resistance current curve and the voltage-inductance current curve comprises the following steps:
and according to no-load test data, solving a voltage-resistance current curve and a voltage-inductance current curve corresponding to the nonlinear resistor and the nonlinear inductor in the excitation branch by using a piecewise linearization method.
Further, the voltage-inductor current curve represents the saturation characteristic of the nonlinear inductor of the excitation branch providing the main flux, and the voltage-resistor current curve represents the saturation characteristic of the nonlinear resistor of the excitation branch providing the no-load loss.
Further, a magnetic circuit model of the single-phase four-column transformer is established, and a standard inductance matrix is obtained according to the magnetic circuit model, specifically:
and establishing a magnetic circuit uniformly considering main flux and leakage flux, and solving the standard inductance matrix through the leakage flux and the main flux.
Furthermore, according to the magnetic circuit structure of the single-phase four-column transformer, an iron core magnetic conductance model is obtained, specifically,
according to the symmetry of the magnetic circuit structure, the single-phase four-column structure is equivalent to two single-phase three-column (one main column and two side columns) structures, and an iron core magnetic conductance model is established:
wherein the content of the first and second substances,
uoc is the transformer port no-load voltage, and Ioc is the port no-load current.
Further, the piecewise linearized flux guide model is:
wherein u is i 、u i-1 、i L,i 、i L,i-1 The values of u and i corresponding to two endpoints of a linear section where the voltage-inductance current curve of the excitation current is located are calculated according to the previous moment.
Further, after determining a linear segment where the exciting current is located and calculating the magnetic conductance of the iron core and the inductance matrix at this time through the piecewise-linearized magnetic conductance model and the standard inductance matrix, the method further includes: and calculating the nonlinear inductor current flowing through the nonlinear inductor at the next moment on the primary side and the secondary side by a trapezoidal method and a backward Euler method.
Further, a nonlinear inductor flowing through the nonlinear inductor at the next moment on the primary side and the secondary side is calculated by a trapezoidal method and a backward Euler method, specifically,
under the condition that the iron core conductance is not changed, calculating the nonlinear inductance of the nonlinear inductance flowing through the secondary side at the next moment by a trapezoidal method;
when the magnetic structure or the magnetic conductance of the iron core changes, in 1,2 time points of sudden change, a retreating Euler method is adopted to solve, and then a trapezoidal method is adopted to calculate the nonlinear inductance of which one secondary side flows through the nonlinear inductance at the next time.
Further, according to the iron core magnetic conductance, the inductance matrix, the transient model of the transformer port and the nonlinear resistance current at this time, the time domain currents at the two ends of the single-phase four-column transformer are obtained, specifically:
calculating the current of the nonlinear resistor flowing through the nonlinear resistor at the next moment according to the winding voltage and the voltage-resistor current curve at the previous moment;
and adding the current passing through the nonlinear resistor at the next moment and the current passing through the nonlinear inductor at the next moment to obtain the time domain current at two ends of the single-phase four-column transformer.
Compared with the prior art, the embodiment of the invention provides a method for creating a saturation model of a single-phase four-column transformer, which comprises the steps of firstly simulating an excitation branch circuit by connecting a nonlinear resistor and a nonlinear inductor in parallel, and obtaining a voltage-resistance current curve and a voltage-inductance current curve of the excitation branch circuit by using a piecewise linearization method through no-load test data; secondly, establishing a magnetic circuit of the single-phase four-column transformer, wherein the main flux leakage flux and the magnetic flux leakage flux are uniformly considered, solving a relational expression of an inductance matrix L and the magnetic conductance of the iron core, and then enabling the iron core structure to be equivalent to a single-phase three-column structure through symmetry to obtain a relational expression of the magnetic conductance of the iron core and exciting current; and finally, performing electromagnetic transient simulation, calculating exciting current according to the current of the primary and secondary side windings at the previous moment, judging the position of the exciting current on a voltage-inductance current curve, calculating the current of the iron core and an inductance matrix L at the current moment, calculating the current of the secondary side windings at the next moment by using a back-off Euler method, calculating the loss current flowing through a nonlinear resistor according to the voltage of the winding at the previous moment and the voltage-resistance current curve, and adding the loss current into the current of the primary side to obtain the current of each side of the single-phase four-column transformer. Compared with a finite element and field circuit coupling method, the method has the advantages that the single-phase four-column transformers with different sizes do not need to be modeled again, the ratio of the cross-sectional area and the length of the iron yoke, the side yoke and the side column relative to the main column only needs to be input in the size of the iron core, and the method has the advantages of being fast in calculation, high in efficiency, easy to use in engineering and the like. Regarding the transformer saturation model, a typical magnetization curve capable of reflecting the saturation characteristic is provided, but the magnetization curve of the single silicon steel sheet measured under the standard condition is inaccurate for reflecting the saturation characteristic of the whole product-grade transformer and needs to be corrected; the invention adopts no-load test data, can integrally simulate the iron core saturation condition and better accords with the actual operation characteristics of the product-level transformer. And the voltage-resistance current curve of the non-linear resistor of the excitation branch calculated by the no-load test data is used for reflecting the no-load loss of the iron core, and is more accurate compared with the condition of only considering the non-linear inductor.
Drawings
Fig. 1 is a flowchart of a method for creating a saturation model of a single-phase four-column transformer according to the present invention;
FIG. 2 is a voltage-resistance current curve through a nonlinear resistor calculated using a piecewise linearization method based on no-load test data;
FIG. 3 is a voltage-inductor current curve calculated by a piecewise linearization method according to no-load test data and flowing through a nonlinear inductor;
FIG. 4 is a schematic diagram of a single-phase four-pole magnetic circuit structure equivalent to a single-phase three-pole magnetic circuit structure;
FIG. 5 is a comparison graph of simulated and measured waveforms under the 0.7A DC bias condition in the example;
FIG. 6 is a graph comparing simulated and measured waveforms under 1.2A DC bias in the example;
fig. 7 is a block diagram of an intelligent terminal according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without any inventive step, are within the scope of the present invention.
It should be noted that, the step numbers in the text are only for convenience of explanation of the specific embodiments, and do not serve to limit the execution order of the steps. The method provided by the embodiment can be executed by the relevant server, and the server is taken as an example for explanation below.
The technical scheme of the invention is described in detail by taking an isometric reduced single-phase four-column iron core model (the diameter of an iron core is 1/10, and the volume is 1/1000) designed by a typical structure of a converter transformer (model: ZZDFPZ-237400/500-200) in a certain converter station as an example.
As shown in fig. 1 to 6, an embodiment of the present invention provides a method for creating a saturation model of a single-phase four-limb transformer, where the single-phase four-limb transformer is a transformer with a single-phase four-limb core structure and includes two main limbs and two side limbs, and the method includes steps S11 to S18:
and S11, according to the no-load test data, solving a voltage-resistance current curve and a voltage-inductance current curve corresponding to the nonlinear resistor and the nonlinear inductor in the excitation branch circuit by using a piecewise linearization method.
Specifically, based on the no-load test data in table 1, a voltage-resistance current curve and a voltage-inductance current curve corresponding to the nonlinear resistor and the nonlinear inductor in the excitation branch are obtained by a piecewise linearization method to simulate the saturation characteristic of the excitation branch of the single-phase four-column transformer. The voltage-resistance current curve represents the saturation characteristic of the nonlinear inductor which provides main magnetic flux for the excitation branch, and the voltage-inductance current curve represents the saturation characteristic of the nonlinear resistor which provides no-load loss for the excitation branch.
TABLE 1 No-load test data
The model for obtaining the voltage-resistance current curve is as follows:
wherein j =1,2, …, k, P k Is the no-load loss in table 1; u. of k For each voltage peak value of the no-load voltage, so u k Need to multiply on the basis of the data of Table 1
And as the phase angle increases and the voltage decreases,
respectively corresponding to the phase angles from the k +1 th point to the 1 st point in the voltage-resistance current curve.
When k is calculated from small to large, only i in the model is the result of the previous steps in calculating the k-th point due to the sigma summation operation R,k Is an unknown quantity, and is with respect to i R,k Substituting the no-load loss and the no-load voltage into the above formula from small to large, and sequentially solving to obtain i R,1 ，i R,2 ，...，i R,n 。
The model for obtaining the voltage-inductance current curve is as follows:
wherein, I k The effective value of the no-load current in the table 1 is shown; and as the phase angle increases and the voltage decreases,
respectively corresponding to the phase angles from the (k + 1) th point to the (1) th point in the voltage-resistance current curve.
At the solution i L,k First, all i needs to be calculated R,k Then according to k, the calculation is carried out from small to large, because of the sigma summation operation, the calculation results of the previous steps are used when the k step is calculated, and the corresponding idle current effective value, the voltage peak value and the corresponding i in the previous section are obtained R,1 ，i R,2 ，…i R,k And i calculated in the previous steps L Substituting, only i in the model L,k Is unknown and can be simplified to obtain information about i L,k The equation is solved, positive solution is obtained according to the current relation, and then i can be obtained in sequence L,1 ,i L,2 ,…,i L,n 。
The results of the voltage-resistance current curve and the voltage-inductance current curve are shown in table 2. The voltage-resistance current curve is shown in fig. 2, and the voltage-inductor current curve is shown in fig. 3.
TABLE 2 Voltage-resistance Current Curve and Voltage-inductance Current Curve calculation results
And S12, establishing a magnetic circuit uniformly considering main flux and leakage flux, and solving the standard inductance matrix through the leakage flux and the main flux.
Specifically, a magnetic circuit with the main flux and the leakage flux of the single-phase four-column transformer considered uniformly is established, an incidence matrix corresponding to the magnetic circuit is written in a column, a block matrix is determined according to the relation between the incidence matrix and the magnetic conductance matrix of each branch, and the inductance matrix is determined according to the block matrix and the winding voltage matrix.
And S13, calculating the leakage magnetic conductance in the magnetic circuit according to the load loss, the load current and the short-circuit impedance measured in the rated load test of the transformer.
When the magnetic circuit equation of the transformer is solved, the magnetic conductance of the leakage magnetic circuit is only related to the material and the geometric dimension of the magnetic circuit, so that the value of the magnetic conductance of the leakage magnetic circuit can be regarded as constant under the normal operation and saturation state of the transformer, and the leakage magnetic conductance can be obtained by the load loss, the short-circuit impedance, the winding resistance and the reactance which are measured in a rated load test.
And S14, obtaining an iron core magnetic conductance model according to the magnetic circuit structure of the single-phase four-column transformer.
Specifically, a model of iron core magnetic conductance is obtained according to the magnetic circuit structure of the single-phase four-column transformer. Under the no-load condition, main magnetic flux is far greater than leakage magnetic flux, so when using the main magnetic conductance of no-load condition calculation, the leakage magnetic conductance can be ignored. Since there are many single-phase four-pole transformers, the structure is equivalent to two single-phase three-pole (one main pole and two side poles) structures according to the symmetry of the magnetic structure, and the structure of the single-phase four-pole magnetic circuit and the equivalent structure of the single-phase three-pole magnetic circuit are shown in fig. 4. Wherein the magnetic conductance of the iron core main column is P w The magnetic conductance of the yoke between the two main columns is P y The upper and lower parts of the side yoke have a magnetic conductance P t1 The side pole magnetic conductance is P t2 The cross-sectional area and length ratio of the iron yoke, the side column and the main column is r Sy 、r St1 、r St2 、r Ly 、r Lt1 、r Lt2 Then, there are:
wherein S i 、L i Respectively representing the cross-sectional area and length of each portion in fig. 4. The core leg permeance is then:
in the formula (I), the compound is shown in the specification,
U oc for no-load voltage at the transformer port, I oc Port no load current.
And S15, inputting the voltage-inductive current curve into an iron core magnetic conductance model to obtain a piecewise linearization magnetic conductance model.
The piecewise linearized flux guide model is:
wherein u is i 、u i-1 、i L,i 、i L,i-1 The values of u and i corresponding to two endpoints of a linear section where the voltage-inductance current curve of the excitation current is located are calculated according to the previous moment.
Step S16, calculating the nonlinear inductive current flowing into the nonlinear inductor according to the current of the primary and secondary side windings at the previous moment, judging the position of the nonlinear inductive current on a voltage-inductive current curve, calculating the iron core flux guide and the inductive matrix L at the current moment through the segmented linearized flux guide model and the standard inductive matrix, and calculating the nonlinear inductive current flowing into the nonlinear inductor at the next moment from the primary and secondary side windings through a trapezoidal method and a backward Euler method.
Specifically, electromagnetic transient simulation is carried out, current flowing into the nonlinear inductor is calculated according to the current of the primary and secondary side windings at the previous moment, the position of the nonlinear inductor on a voltage-inductor current curve is judged according to the current, the iron core flux guide and the inductor matrix L at the current moment are calculated according to a segmented linearized flux guide model and the inductor matrix, and then the winding current of the primary and secondary side at the next moment is calculated by utilizing a backward Euler method. Under the condition that the iron core is unchanged in conduction, calculating the winding current of a primary side and a secondary side at the next moment by a trapezoidal method; when the magnetic structure or the magnetic conductance of the iron core changes, in 1,2 time points of sudden change, a retreating Euler method is adopted to solve, and then a trapezoidal method is adopted to calculate the winding current of the primary side and the secondary side at the next time. Wherein the piecewise-linearized flux guide model takes into account saturation characteristics of the magnetic circuit.
And S17, calculating the current of the nonlinear resistor flowing through the nonlinear resistor at the next moment according to the winding voltage and the voltage-resistor current curve at the previous moment. And the current flowing through the nonlinear resistor at the next moment is the current generated by the core loss.
And S18, adding the current of the nonlinear resistor passing through the nonlinear resistor at the next moment and the current of the nonlinear inductor passing through the nonlinear inductor at the next moment to obtain time domain currents at two ends of the single-phase four-column transformer.
It can be understood that, because the invention not only considers the nonlinearity of the iron core as a whole, but also considers the iron core loss as a whole in the form of nonlinear inductance, when no load occurs, the current providing the excitation branch includes nonlinear inductance current (providing iron core excitation) and nonlinear resistance current (generating no load loss current), so that the simulation waveform is more in line with the actual waveform, and has higher precision. And when the single-phase four-column transformer iron core magnetic conductance, the single-phase four-column structure is equivalent to two single-phase three-column structures, so that the formula derivation difficulty is greatly reduced and the calculation speed is increased on the premise of not influencing the precision. In the comparison between the simulation result and the measured value of the example, the error under the normal no-load condition is not more than 2%, and the comparison condition under the direct-current magnetic biasing condition is shown in fig. 5 and 6.
Firstly, simulating an excitation branch by parallel connection of a nonlinear resistor and a nonlinear inductor, and obtaining a voltage-resistance current curve and a voltage-inductance current curve of the excitation branch by a piecewise linearization method through no-load test data; secondly, establishing a magnetic circuit of the single-phase four-column transformer, wherein the main flux leakage flux and the magnetic flux leakage flux are uniformly considered, solving a relational expression of an inductance matrix L and the magnetic conductance of the iron core, and then enabling the iron core structure to be equivalent to a single-phase three-column structure through symmetry to obtain a relational expression of the magnetic conductance of the iron core and exciting current; and finally, performing electromagnetic transient simulation, calculating exciting current according to the current of the primary and secondary side windings at the previous moment, judging the position of the exciting current on a voltage-inductance current curve, calculating the magnetic conductance of the iron core and an inductance matrix L at the current moment, calculating the current of the secondary side windings at the next moment by using a retreating Euler method, calculating the loss current flowing through the nonlinear resistor according to the voltage of the winding at the previous moment and the voltage-resistance current curve, and adding the loss current into the current of the primary side to obtain the current of each side of the single-phase four-column transformer. Compared with a field coupling method, the method has the advantages that the single-phase four-column transformers with different sizes do not need to be modeled again, the ratio of the cross-sectional area and the length of the iron yoke, the side yoke and the side column relative to the main column only needs to be input in the size of the iron core, and the method has the advantages of being fast in calculation, high in efficiency, easy to use in engineering and the like. Regarding the transformer saturation model, what can typically reflect the saturation characteristic is a magnetization curve, but the magnetization curve of the single silicon steel sheet measured under the standard condition is used for reflecting that the saturation characteristic of the whole product-grade transformer is inaccurate and needs to be corrected; the invention adopts no-load test data, can integrally simulate the iron core saturation condition and better accords with the actual operation characteristics of the product-level transformer. And the voltage-resistance current curve of the non-linear resistor of the excitation branch calculated by the no-load test data is used for reflecting the no-load loss of the iron core, and is more accurate compared with the condition of only considering the non-linear inductor.
It should be understood that, although the steps in the above-described flowcharts are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a portion of the steps in the above-described flowcharts may include multiple sub-steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of performing the sub-steps or the stages is not necessarily sequential, but may be performed alternately or alternatingly with other steps or at least a portion of the sub-steps or stages of other steps.
An embodiment of the present invention further provides a computer-readable storage medium, where the computer-readable storage medium includes a stored computer program; when the computer program runs, the device on which the computer readable storage medium is located is controlled to execute the method for creating the saturation model of the single-phase four-column transformer according to any one of the above embodiments.
An embodiment of the present invention further provides an intelligent terminal, which is shown in fig. 7 and is a block diagram of a preferred embodiment of the intelligent terminal provided by the present invention, the intelligent terminal includes a processor 10, a memory 20, and a computer program stored in the memory 20 and configured to be executed by the processor 10, and the processor 10, when executing the computer program, implements the method for creating the saturation model of the single-phase four-pole transformer according to any one of the embodiments described above.
Preferably, the computer program can be divided into one or more modules/units (e.g. computer program 1, computer program 2,) which are stored in the memory 20 and executed by the processor 10 to accomplish the present invention. The one or more modules/units may be a series of computer program instruction segments capable of performing specific functions, which are used for describing the execution process of the computer program in the intelligent terminal.
The Processor 10 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, a discrete Gate or transistor logic device, a discrete hardware component, etc., the general purpose Processor may be a microprocessor, or the Processor 10 may be any conventional Processor, the Processor 10 is a control center of the smart terminal, and various interfaces and lines are used to connect various parts of the smart terminal.
The memory 20 mainly includes a program storage area that may store an operating system, an application program required for at least one function, and the like, and a data storage area that may store related data and the like. In addition, the memory 20 may be a high speed random access memory, may also be a non-volatile memory, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash Card (Flash Card), and the like, or the memory 20 may also be other volatile solid state memory devices.
It should be noted that the above-mentioned intelligent terminal may include, but is not limited to, a processor and a memory, and those skilled in the art will understand that the structural block diagram of fig. 7 is only an example of the intelligent terminal, and does not constitute a limitation of the intelligent terminal, and may include more or less components than those shown, or combine some components, or different components.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.
Claims (6)
1. A method for creating a saturation model of a single-phase four-column transformer is characterized by comprising the following steps:
according to no-load test data, a voltage-resistance current curve and a voltage-inductance current curve corresponding to a nonlinear resistor and a nonlinear inductor in an excitation branch are obtained by a piecewise linearization method;
establishing a magnetic circuit model of the single-phase four-column transformer, and obtaining a standard inductance matrix according to the magnetic circuit model, wherein the standard inductance matrix specifically comprises the following steps: establishing a magnetic circuit which uniformly considers main magnetic flux and leakage magnetic flux, and solving the standard inductance matrix through the leakage magnetic flux and the main magnetic flux;
according to the magnetic circuit structure of the single-phase four-column transformer, an iron core magnetic conductance model is obtained, and the method specifically comprises the following steps: according to the symmetry of a magnetic circuit structure of the single-phase four-column transformer, the single-phase four-column structure is equivalent to two single-phase three-column structures, and an iron core magnetic conductance model is established;
obtaining a segmented linearized flux guide model according to the voltage-resistance current curve, the voltage-inductance current curve, the flux leakage guide and the iron core flux guide model; the leakage magnetic conductance is obtained by load loss, load current and short-circuit impedance measured in a rated load test of the transformer;
calculating the nonlinear inductor current flowing into the nonlinear inductor according to the current of the secondary side winding at the last moment;
judging a linear section where the current flowing into the nonlinear inductor is positioned, and calculating the magnetic conductance of the iron core and the inductance matrix at the moment through the segmented linearized magnetic conductance model and the standard inductance matrix;
obtaining time domain currents at two ends of the single-phase four-column transformer according to the iron core magnetic conductance, the inductance matrix, the transient model of the transformer port and the nonlinear resistance current at the moment, and specifically: calculating the current of the nonlinear resistor flowing through the nonlinear resistor at the next moment according to the winding voltage and the voltage-resistor current curve at the previous moment; and adding the current passing through the nonlinear resistor at the next moment and the current of the nonlinear inductor flowing through the nonlinear inductor at the next moment in a vector manner to obtain the time domain currents at two ends of the single-phase four-column transformer.
2. The method for creating the saturation model of the single-phase four-pole transformer as claimed in claim 1, wherein the voltage-inductor current curve represents the saturation characteristic of the non-linear inductor of the excitation branch providing the main flux, and the voltage-resistor current curve represents the saturation characteristic of the non-linear resistor of the excitation branch providing the no-load loss.
3. The method for creating a saturation model of a single-phase four-column transformer according to claim 1, wherein a core flux guide model is obtained based on a magnetic structure of the single-phase four-column transformer, and in particular,
according to the symmetry of the magnetic circuit structure, the single-phase four-column structure is equivalent to two single-phase three-column structures, and an iron core magnetic conductance model is established:
wherein the content of the first and second substances,
uoc is the no-load voltage of the transformer port, ioc is the no-load current of the port, r Sy Is the sectional area ratio of the yoke to the main column, r St1 Is the ratio of the cross-sectional area of the return yoke to the main column, r St2 Is the ratio of the cross-sectional area of the side column to the main column, r Ly Is the length ratio of the yoke to the main column, r Lt1 Is the length ratio of the return yoke to the main column, r Lt2 Is the length ratio of the side column to the main column.
4. The method for creating the saturation model of the single-phase four-column transformer according to claim 3, wherein the piecewise-linearized flux guide model is:
wherein u is i 、u i-1 、i L,i 、i L,i-1 The values of u and i corresponding to two endpoints of a linear section where the voltage-inductance current curve of the excitation current is located are calculated according to the previous moment.
5. The method for creating the saturation model of the single-phase four-column transformer according to claim 4, wherein after determining a linear segment where the exciting current is located and calculating a core flux guide and an inductance matrix at the time through the flux guide model of the piecewise linearization and a standard inductance matrix, the method further comprises: and calculating the nonlinear inductor current flowing through the nonlinear inductor at the next moment on the primary side and the secondary side through a trapezoidal method and a backward Euler method.
6. The method for creating the saturation model of the single-phase four-column transformer as claimed in claim 5, wherein the nonlinear inductance flowing through the nonlinear inductance at the next moment of primary and secondary sides is calculated by a trapezoidal method and a backward Euler method, specifically,
under the condition that the magnetic conductance of the iron core is not changed, calculating the nonlinear inductance of the nonlinear inductance flowing through the secondary side at the next moment by a trapezoidal method;
when the magnetic structure or the magnetic conductance of the iron core changes, in 1,2 time points of sudden change, a retreating Euler method is adopted to solve, and then a trapezoidal method is adopted to calculate the nonlinear inductance of the nonlinear inductance flowing through the primary side and the secondary side at the next time.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104657599A (en) * | 2015-01-30 | 2015-05-27 | 国家电网公司 | Single-phase transformer model for calculating direct current magnetic bias through equivalent differential electric/magnetic path principle |
| CN106649935A (en) * | 2016-09-27 | 2017-05-10 | 华北电力大学 | Real-time calculation method for no-load direct-current magnetic bias exciting current of ultra-high-voltage transformer |
| CN110175351A (en) * | 2019-04-15 | 2019-08-27 | 南方电网科学研究院有限责任公司 | A kind of converter power transformer modeling method |
-
2021
- 2021-03-30 CN CN202110344106.3A patent/CN113190964B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104657599A (en) * | 2015-01-30 | 2015-05-27 | 国家电网公司 | Single-phase transformer model for calculating direct current magnetic bias through equivalent differential electric/magnetic path principle |
| CN106649935A (en) * | 2016-09-27 | 2017-05-10 | 华北电力大学 | Real-time calculation method for no-load direct-current magnetic bias exciting current of ultra-high-voltage transformer |
| CN110175351A (en) * | 2019-04-15 | 2019-08-27 | 南方电网科学研究院有限责任公司 | A kind of converter power transformer modeling method |
Non-Patent Citations (5)
| Title |
|---|
| 单相四柱试验变压器铁心磁化曲线等效与直流偏磁分析;王泽忠等;《电工电能新技术》;20200823(第08期);全文 * |
| 基于JA理论的750kV自耦变压器直流偏磁研究;彭晨光等;《华东电力》;20100324(第03期);全文 * |
| 基于K值法的单相四柱式特高压主体变的GIC-Q损耗计算;刘连光等;《高电压技术》;20170711(第07期);全文 * |
| 基于瞬态场路耦合模型的变压器直流偏磁计算;潘超等;《电工技术学报》;20130526(第05期);全文 * |
| 采用统一磁路及空载试验的变压器饱和模型;林济铿等;《高电压技术》;20110228(第02期);全文 * |
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