CN112711924A - High-frequency modeling method for high-capacity high-frequency transformer - Google Patents
High-frequency modeling method for high-capacity high-frequency transformer Download PDFInfo
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- 238000004804 winding Methods 0.000 claims abstract description 18
- 238000012795 verification Methods 0.000 claims description 9
- 230000005540 biological transmission Effects 0.000 description 12
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/30—Circuit design
- G06F30/32—Circuit design at the digital level
- G06F30/33—Design verification, e.g. functional simulation or model checking
- G06F30/3308—Design verification, e.g. functional simulation or model checking using simulation
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/30—Circuit design
- G06F30/32—Circuit design at the digital level
- G06F30/33—Design verification, e.g. functional simulation or model checking
- G06F30/3323—Design verification, e.g. functional simulation or model checking using formal methods, e.g. equivalence checking or property checking
Abstract
A high-frequency modeling method for a high-capacity high-frequency transformer belongs to the technical field of power systems and comprises the steps of establishing a dual-port equivalent circuit model of the high-capacity high-frequency transformer, wherein the equivalent circuit model is formed by connecting impedance Z10, a winding Lm and impedance Rm in parallel, connecting impedance Z20 with a winding Ls and impedance Rs in series, arranging impedance Z12 between a primary coil and a secondary coil, and connecting Z12 to represent mutual impedance between the primary coil and the secondary coil, and then combining an impedance value obtained through measurement and a high-frequency model considering parasitic parameters to obtain three parameters of Z10, Z20 and Z12 by using a conventional vector matching method so as to obtain a corresponding high-frequency model. The equivalent circuit model of the parasitic capacitance is considered, the equivalent circuit model is established on the basis of the actually measured transformer port circuit characteristics, and the circuit model can better reflect the electrical characteristics of the transformer.
Description
Technical Field
The invention belongs to the technical field of power systems, and particularly relates to a high-frequency modeling method for a high-capacity high-frequency transformer.
Background
During the operation of the ultra-high voltage power transmission system, the threat of overvoltage of power frequency, operation, thunder and lightning and the like can be born. The lightning overvoltage has the largest impact on an extra-high voltage system, and according to relevant statistics, lightning strike is the most main reason for tripping of a power transmission line, and the lightning overvoltage is one of important factors for causing insulation failure of power equipment. Meanwhile, China is also a multi-thunder country, and the east coastal region, south China, the west China and parts of China belong to the regions with the most frequent lightning activities. The ultra-high voltage transmission line has long transmission distance, passes through a plurality of provinces, and has complex climate and terrain along the way, so that the probability of lightning stroke of the ultra-high voltage transmission line is higher. After the transmission line is struck by lightning, lightning current can invade an extra-high voltage transformer substation in the form of lightning invasion waves, and the lightning invasion waves can cause insulation breakdown of winding equipment in the substation and insulation flashover outside some equipment, so that the safe operation of the equipment in the substation is seriously threatened. Theoretically, the higher the voltage grade of the ultra-high voltage alternating current transmission is, the larger the transmission capacity is, the more serious the problems of loss and system disturbance caused by insulation faults are, and whether the overvoltage calculation and the insulation design are reasonable or not directly influences the economy of the whole project and even the safety of the whole project. Therefore, the method has important significance in accurately calculating the overvoltage level of the extra-high voltage alternating current system.
At present, software simulation is mostly adopted for lightning overvoltage calculation, and relatively universal simulation software comprises an EMTP electromagnetic transient simulation program and a lightning protection calculation program FLASH of an IEEE lightning protection working group, wherein the EMTP is most widely applied. The basis of EMTP simulation is to establish an overvoltage simulation model of a power transmission system, wherein a transformer is used as core equipment in the power system, and the model has great influence on a simulation result and is a key point in overvoltage simulation modeling work. The common models for overvoltage simulation at present are: a port capacitance model, a frequency response characteristic model, and a transformer transfer over-voltage model. The port capacitance model utilizes a lumped parameter capacitance equivalent transformer winding to ground capacitance, inter-winding capacitance and series capacitance in the winding, and generally utilizes the voltage response characteristic of the measuring transformer under the step wave to calculate and obtain or directly utilize a standard recommended value. The port capacitance model does not consider the magnetic characteristics of the transformer winding, and the port characteristics of the transformer under the lightning overvoltage cannot be accurately reflected. The frequency response model simulates the transformer by an RLC series-parallel circuit, and theoretically, the model can better reflect the port characteristics of the transformer under the lightning overvoltage, but few documents are used for researching a modeling method and a parameter extraction method of the model, so that further research is needed.
Aiming at the problems existing in the lightning overvoltage simulation modeling of the existing extra-high voltage transformer, the invention considers different applicable scenes in the lightning overvoltage simulation and establishes a single-port model without considering the lightning overvoltage transfer characteristic and a double-port model with considering the lightning overvoltage transfer characteristic on the basis of the impedance broadband characteristic measured by an impedance analyzer. In the modeling process, the accuracy and passivity of modeling are ensured by using methods such as vector matching, passive correction and the like. And finally, the accuracy of the model established by the invention is verified by using the time domain response characteristic of the extra-high voltage alternating current transformer measured on site.
Disclosure of Invention
In order to solve the technical problems, the equivalent circuit model of the parasitic capacitance is considered, the equivalent circuit model is established on the basis of the actually measured transformer port circuit characteristics, and the circuit model can better reflect the electrical characteristics of the transformer.
The technical scheme adopted by the invention is as follows:
a high-frequency modeling method for a large-capacity high-frequency transformer comprises the steps of establishing a dual-port equivalent circuit model of the large-capacity high-frequency transformer, wherein the equivalent circuit model comprises impedance Z10, a winding Lm and impedance Rm which are connected in parallel, and impedance Z20, a winding Ls and impedance Rs which are connected in series, wherein Z10 represents parasitic impedance between a primary coil, Z20 represents parasitic impedance of a secondary coil, impedance Z12 is arranged between the primary coil and the secondary coil, Z12 represents mutual impedance between the primary coil and the secondary coil, and then three parameters Z10, Z20 and Z12 can be obtained by combining measured impedance values and the provided high-frequency model considering parasitic parameters through a conventional vector matching method, so that a corresponding high-frequency model is obtained.
Further, the measuring method comprises the following steps: during measurement, open-short circuit verification and load verification are respectively carried out to reduce the influence of the measurement lead on the measurement result to the maximum extent,
the measurement steps are as follows:
(1) completing wiring, wherein a wiring method of 'shielding layer double-end grounding' is adopted;
(2) the method comprises the following steps of measuring the open-circuit impedance characteristic Zo at the tail end of a cable, measuring the short-circuit impedance Zs at the tail end of the cable, connecting the tail end of the cable with a load, measuring the load impedance characteristic Zlm, and directly measuring the real impedance characteristic Zl of the load;
(3) the end of the cable is connected with the tested equipment, and the broadband impedance Zxm is measured;
(4) and verifying by using a verification formula and measurement data to obtain the impedance characteristic Zx after the equipment is verified.
The invention has the beneficial effects that:
the high-frequency modeling method of the high-capacity high-frequency transformer is large in capacity, suitable for long-distance large-capacity new energy transmission and beneficial to building of long-distance power transmission lines.
The equivalent circuit model of the parasitic capacitance is considered, the equivalent circuit model is established on the basis of the actually measured transformer port circuit characteristics, and the circuit model can better reflect the electrical characteristics of the transformer.
The circuit equivalent model is generally suitable for high-frequency modeling of a high-capacity high-frequency transformer with a higher frequency band.
The high-frequency mechanism model of the high-capacity high-frequency transformer fully considers the inductance characteristic and the parasitic capacitance effect of a main magnetic circuit of the high-capacity high-frequency transformer, comprises the capacitance between a winding and a magnetic core and between the winding and a shell, and the parameters of the model have clear physical significance.
Drawings
FIG. 1 is a schematic modeling flow diagram;
FIG. 2 is a schematic diagram of a super-large capacity high-frequency transformer;
fig. 3 is a high-frequency equivalent circuit model of a large-capacity high-frequency transformer.
Detailed Description
The invention is described in detail below with reference to the figures and examples.
The basis of the modeling of the invention is the electrical characteristics of the transformer measured by the impedance tester, so that the accuracy of the measurement result is ensured firstly. The large-capacity high-frequency transformer is large, a long measuring lead wire can be used when an impedance analyzer is used for measurement, the length of the lead wire can reach 30 m sometimes, and the long measuring lead wire has great influence on a measurement result.
The impedance matching modeling method is a common circuit modeling method, and utilizes measured impedance/admittance parameters to perform curve by combining with a mathematical expression of an empirical formula so as to obtain an equivalent circuit model.
The simulation result and the actual measurement result of the double-port equivalent circuit model are well matched on various voltage gradients. The difference between the simulation result and the actual measurement result based on the traditional power frequency model is large, and the maximum error of the model peak value provided by the invention is only 10%. Therefore, the equivalent model of the port of the extra-high voltage alternating-current transformer is suitable for calculating the operation overvoltage of the transformer substation.
The invention takes a large-capacity high-frequency transformer as a research object, and researches such as high-frequency equivalent modeling, parameter extraction, simulation comparison of an output port under different engineering application scenes, comparison analysis of an improved frequency model and a conventional steady-state model and the like are carried out under the condition of lightning overvoltage.
The method is used for measuring the parasitic parameters of the high-capacity high-frequency transformer, transmitting and storing the parasitic parameters, fitting the functions of the parasitic parameters, considering the generation of the equivalent circuit of the parasitic parameters and the passive optimization of the equivalent circuit elements. A high-frequency equivalent circuit model containing parasitic inductance of the large-capacity high-frequency transformer is obtained through a high-frequency modeling method, is used for frequency domain and time domain simulation, and provides a theoretical basis for the research of analyzing the transmission characteristics and the transient voltage-sharing problem of the large-capacity high-frequency transformer.
During measurement, open-short circuit verification and load verification are respectively carried out so as to reduce the influence of the measurement lead on the measurement result to the maximum extent.
The measurement steps are as follows:
(1) and finishing wiring, wherein a wiring method of 'double-end grounding' of a shielding layer is adopted.
(2) The method comprises the steps of measuring the open-circuit impedance characteristic Zo at the tail end of a cable, measuring the short-circuit impedance Zs at the tail end of the cable, connecting the tail end of the cable with a load, measuring the load impedance characteristic Zlm, and directly measuring the real impedance characteristic Zl of the load.
(3) The cable end is connected with the device to be tested, and the broadband impedance Zxm is measured.
(4) And verifying by using a verification formula and measurement data to obtain the impedance characteristic Zx after the equipment is verified.
The structure of the large-capacity high-frequency transformer is schematically shown in fig. 2. The primary side of the transformer is formed by a series winding and a common winding, and a magnetic core is arranged between the two windings; the secondary winding is a single low voltage winding and also contains a magnetic core. The structure of the transformer is very complex, and the existing transformer modeling method cannot complete the modeling work.
The transformer two-port equivalent circuit model shown in fig. 3. Three impedances Z10, Z20 and Z12 are added to the conventional transformer model in consideration of the characteristics of the parasitic parameters at high frequencies. Where Z10 represents the parasitic impedance between the primary coil, Z20 represents the parasitic impedance of the secondary coil, and Z12 represents the mutual impedance between the primary and secondary. After the three parasitic parameters are considered, the high-frequency characteristics of the high-frequency transformer under the lightning overvoltage can be well reflected.
Combining the measured impedance value and the proposed high-frequency model considering the parasitic parameters, three parameters of Z10, Z20 and Z12 can be obtained by using a conventional vector matching method, so as to obtain the corresponding high-frequency model.
Claims (2)
1. A high-frequency modeling method for a high-capacity high-frequency transformer is characterized by comprising the following steps: the method comprises the steps of establishing a dual-port equivalent circuit model of the large-capacity high-frequency transformer, wherein the equivalent circuit model comprises impedance Z10, a winding Lm and impedance Rm which are connected in parallel, impedance Z20 is connected with a winding Ls and an impedance Rs in series, Z10 represents parasitic impedance between primary coils, Z20 represents parasitic impedance of secondary coils, impedance Z12 is arranged between the primary coils and the secondary coils, Z12 represents mutual impedance between the primary coils and the secondary coils, and then three parameters Z10, Z20 and Z12 can be obtained by a conventional vector matching method by combining measured impedance values and a high-frequency model considering parasitic parameters, so that a corresponding high-frequency model is obtained.
2. The high-frequency modeling method for the large-capacity high-frequency transformer according to claim 1, characterized in that: the measuring method comprises the following steps: during measurement, open-short circuit verification and load verification are respectively carried out to reduce the influence of the measurement lead on the measurement result to the maximum extent,
the measurement steps are as follows:
(1) completing wiring, wherein a wiring method of 'shielding layer double-end grounding' is adopted;
(2) the method comprises the following steps of measuring the open-circuit impedance characteristic Zo at the tail end of a cable, measuring the short-circuit impedance Zs at the tail end of the cable, connecting the tail end of the cable with a load, measuring the load impedance characteristic Zlm, and directly measuring the real impedance characteristic Zl of the load;
(3) the end of the cable is connected with the tested equipment, and the broadband impedance Zxm is measured;
(4) and verifying by using a verification formula and measurement data to obtain the impedance characteristic Zx after the equipment is verified.
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| CN202011451654.8A CN112711924A (en) | 2020-12-11 | 2020-12-11 | High-frequency modeling method for high-capacity high-frequency transformer |
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| CN202011451654.8A CN112711924A (en) | 2020-12-11 | 2020-12-11 | High-frequency modeling method for high-capacity high-frequency transformer |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11202008A (en) * | 1998-01-08 | 1999-07-30 | Hewlett Packard Japan Ltd | Method and apparatus for calibrating hybrid transformer |
| CN104679959A (en) * | 2015-03-12 | 2015-06-03 | 华北电力大学（保定） | Modeling method for broadband equivalent circuit of 1,000kV extra-high-voltage capacitive voltage divider |
| CN105203853A (en) * | 2015-09-11 | 2015-12-30 | 国网智能电网研究院 | Measuring method for stray capacitance of large-capacity high-frequency transformer |
| CN107037312A (en) * | 2016-11-28 | 2017-08-11 | 国家电网公司 | A kind of Transformer Winding Building of Simulation Model method for frequency sweep impedance method |
| CN108828318A (en) * | 2018-02-26 | 2018-11-16 | 华北电力大学 | A method of extracting cascade connection type isolating transformer parasitic capacitance |
-
2020
- 2020-12-11 CN CN202011451654.8A patent/CN112711924A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11202008A (en) * | 1998-01-08 | 1999-07-30 | Hewlett Packard Japan Ltd | Method and apparatus for calibrating hybrid transformer |
| CN104679959A (en) * | 2015-03-12 | 2015-06-03 | 华北电力大学（保定） | Modeling method for broadband equivalent circuit of 1,000kV extra-high-voltage capacitive voltage divider |
| CN105203853A (en) * | 2015-09-11 | 2015-12-30 | 国网智能电网研究院 | Measuring method for stray capacitance of large-capacity high-frequency transformer |
| CN107037312A (en) * | 2016-11-28 | 2017-08-11 | 国家电网公司 | A kind of Transformer Winding Building of Simulation Model method for frequency sweep impedance method |
| CN108828318A (en) * | 2018-02-26 | 2018-11-16 | 华北电力大学 | A method of extracting cascade connection type isolating transformer parasitic capacitance |
Non-Patent Citations (1)
| Title |
|---|
| 左军;李君;: "大容量高频高压变压器的研究与设计", 电力学报, no. 03 * |
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Effective date of registration: 20210916 Address after: 125099 No. 1, Longwan South Street, Longgang District, Huludao City, Liaoning Province Applicant after: HULUDAO POWER SUPPLY COMPANY OF STATE GRID LIAONING ELECTRIC POWER Co.,Ltd. Applicant after: STATE GRID LIAONING ELECTRIC POWER SUPPLY Co.,Ltd. Applicant after: STATE GRID CORPORATION OF CHINA Address before: 125000 No.1 Longwan South Street, Longgang District, Huludao City, Liaoning Province Applicant before: HULUDAO POWER SUPPLY COMPANY OF STATE GRID LIAONING ELECTRIC POWER Co.,Ltd. |
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