CN114362101B - Excitation variation protection method for double-core asymmetric phase-shifting transformer - Google Patents
Excitation variation protection method for double-core asymmetric phase-shifting transformer Download PDFInfo
- Publication number
- CN114362101B CN114362101B CN202210028950.XA CN202210028950A CN114362101B CN 114362101 B CN114362101 B CN 114362101B CN 202210028950 A CN202210028950 A CN 202210028950A CN 114362101 B CN114362101 B CN 114362101B
- Authority
- CN
- China
- Prior art keywords
- current
- transformer
- phase
- winding
- excitation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000005284 excitation Effects 0.000 title claims abstract description 45
- 238000000034 method Methods 0.000 title claims abstract description 26
- 238000004364 calculation method Methods 0.000 claims abstract description 20
- 230000009471 action Effects 0.000 claims abstract description 7
- 238000004804 winding Methods 0.000 claims description 111
- 230000001105 regulatory effect Effects 0.000 claims description 27
- 230000009466 transformation Effects 0.000 claims description 22
- 230000033228 biological regulation Effects 0.000 claims description 10
- 230000003044 adaptive effect Effects 0.000 claims description 2
- 238000009434 installation Methods 0.000 abstract description 2
- 230000008569 process Effects 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000016507 interphase Effects 0.000 description 3
- 230000010363 phase shift Effects 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 230000005674 electromagnetic induction Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 230000003252 repetitive effect Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 239000013598 vector Substances 0.000 description 1
Abstract
The application discloses an excitation variation protection method for a double-core asymmetric phase-shifting transformer based on a turns ratio intelligent following principle, which comprises the following steps: secondary current phase correction, equipment parameter input, tap real-time gear acquisition, intelligent follow-up calculation of turns ratio, intelligent follow-up calculation of secondary current real-time balance coefficient, real-time compensation of secondary current amplitude, calculation of excitation variation protection differential current and braking current, and identification of coordinate positions of the differential current and the braking current in a proportional action area or a braking area. The application can provide a complete differential protection configuration scheme according to the complex and compact primary structure, frequently-changed gear and CT practical installation of the double-core asymmetric phase-shifting transformer, and provides an engineering feasible technical method for differential protection application of the double-core asymmetric phase-shifting transformer.
Description
Technical Field
The application relates to the field of transformer differential protection, in particular to an excitation variation differential protection method for a double-core asymmetric phase-shifting transformer.
Background
A Transformer (Transformer) is a device for changing an ac voltage using the principle of electromagnetic induction, and the main components are a primary coil, a secondary coil, and an iron core (magnetic core). The main functions are as follows: voltage transformation, current transformation, impedance transformation, isolation, voltage stabilization (magnetic saturation transformers), and the like.
The double-core phase-shifting transformer consists of a series transformer and an exciting transformer, wherein the neutral point is grounded, and the exciting part is not directly connected with the system. Classified according to the regulation characteristics, they are classified into symmetrical type and asymmetrical type. The symmetrical type can change the phase difference of both sides of the phase-shifting transformer, and the asymmetrical type can change the phase difference and the voltage amplitude of the phase-shifting transformer at the same time. By utilizing the characteristics, in the process of the loop closing operation of the power grid, the phase-shifting transformer can enable the voltages and phases on two sides of the loop closing operation switch to tend to be the same, so that very small impact or even no-impact closing is realized, and further, uninterrupted power supply of a load is realized.
The differential protection configuration of the phase-shifting transformer is closely related to the primary structure of the phase-shifting transformer, and the two parts of the series transformer and the exciting transformer are arranged in the same box body, so that the structure is complex. Compared with the conventional transformer, the CT mounting positions and the CT number are limited by the primary compact structure of the phase-shifting transformer, and the engineering configuration and the implementation of differential protection are affected. Especially for the excitation transformer of the phase-shifting transformer, the turns ratio of the primary side and the secondary side is not fixed in the working process, a conventional fixed coefficient cannot be provided for differential flow calculation, and a new differential protection implementation method needs to be designed.
Disclosure of Invention
The application provides an excitation variation protection method for a double-core asymmetric phase-shifting transformer, which aims to solve the problems that the differential protection configuration of the phase-shifting transformer is closely related to the primary structure, the two parts of a series transformer and an excitation transformer are arranged in the same box body, the structure is complex, the turns ratio of a primary side and a secondary side is not fixed in the working process, and a conventional fixed coefficient cannot be provided for differential flow calculation, and the application comprises the following steps:
collecting secondary current data as current excitation quantity of differential protection, carrying out phase correction on secondary current of star-shaped or angle-shaped wiring according to the collected secondary current data, and calculating corrected secondary current data;
acquiring equipment parameter data and tap real-time gear data of a device, and performing turns ratio intelligent following calculation according to the acquired data to obtain balance coefficients Kpn and Kpm of each secondary current;
calculating differential current and braking current of the excitation variable differential protection according to the calculated corrected secondary current data and balance coefficients Kpn and Kpm of each secondary current, and if coordinates of the differential current and the braking current are in a differential proportion action area and no other locking condition exists, performing differential protection action;
the phase correction is: the star-shaped wiring is changed into the angle-shaped wiring, or the angle-shaped wiring is changed into the star-shaped wiring;
the excitation variation protection method of the double-core asymmetric phase-shifting transformer is adaptive to the double-core asymmetric phase-shifting transformer, and the double-core asymmetric phase-shifting transformer is provided with: the primary system side current CT1 of the series transformer, the primary load side current CT2 of the series transformer, the primary side current CT3 of the exciting transformer, the secondary side phase modulation winding N current CT4 of the exciting transformer, the secondary side winding of the series transformer and the secondary side voltage modulation winding M of the exciting transformer.
Preferably, the secondary current data includes: the secondary current of the primary side current CT3 of the exciting transformer and the secondary current of the secondary side phase modulation winding N current CT4 of the exciting transformer.
Preferably, the device parameters include: phase modulation winding N, voltage regulation winding M tap middle gear and corresponding turns ratio; the phase modulation winding N and the voltage regulation winding M have a percentage of turns per gear; the capacity and rated voltage of the nameplate of the transformer; and the primary side current CT3 transformation ratio of the exciting transformer and the secondary side phase modulation winding N current CT4 transformation ratio of the exciting transformer.
Preferably, the current gear of the tap is: the current gear of the phase modulation winding N tap and the current gear of the voltage regulation winding M tap.
Preferably, the calculation formula of the real-time balance coefficient Kpn of the secondary current CT4 of the secondary side phase modulation winding of the exciting transformer is as follows:
Kpn＝Pn*(1+Rn*(Dn-On))*K4/K3
wherein: pn is the turns ratio corresponding to the tap middle gear of the phase modulation winding N; rn is the percentage of turns per gear of the phase modulation winding N; dn is the current gear of the phase modulation N winding tap; on the phase modulation winding N taps middle gear; k3 is the transformation ratio of the primary side current CT3 of the exciting transformer; and K4 is the transformation ratio of the current CT4 of the secondary side phase modulation winding N of the exciting transformer.
Preferably, the calculation formula of the real-time balance coefficient Kpm of the secondary current after the excitation transformer secondary side voltage regulating winding M is subjected to angle connection is as follows:
Kpm＝Pm*(1+Rm*(Dm-Om))*K4/K3
wherein: pm is the turns ratio corresponding to the tap middle gear of the voltage regulating winding M; rm is the percentage of turns per gear of the voltage regulating winding M; the current gear of the winding tap of the Dm voltage-regulating winding M; om is the middle gear of the tap of the voltage regulating winding M; k3 is the transformation ratio of the primary side current CT3 of the exciting transformer; and K4 is the transformation ratio of the current CT4 of the secondary side phase modulation winding N of the exciting transformer.
Preferably, the primary side current CT3 secondary current of the exciting transformer is used as a reference side for calculating the balance coefficient, and the balance coefficient of the primary side current CT3 secondary current of the exciting transformer is 1.
Preferably, the differential current and the braking current have the following calculation formula:
wherein:each phase secondary current after the primary side current CT3 of the exciting transformer is subjected to phase correction; />Phase correction is carried out on the phase-corrected secondary currents of each phase of the N current CT4 of the excitation variable secondary side phase modulation winding; />For each phase secondary current after the M angle connection of the exciting transformer voltage regulating winding, namely each phase secondary current flowing through the N current CT4 of the exciting transformer secondary side phase regulating winding；I dz For said differential current; i zd For the braking current.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the embodiments of the application. It is evident that the drawings in the following description are only some embodiments of the present application and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art.
FIG. 1 is a schematic diagram of a CT exemplary engineering configuration of a dual-core asymmetric phase-shifting transformer to which the present application is applied;
fig. 2 is a flow chart of a method for protecting the excitation variation of the double-core asymmetric phase-shifting transformer.
Detailed Description
Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments may be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the implementations of embodiments of the application. One skilled in the relevant art will recognize, however, that embodiments of the application may be practiced without one or more of the specific details, or with other methods, devices, steps, etc. In other instances, well-known aspects have not been shown or described in detail to avoid obscuring aspects of embodiments of the application.
Furthermore, the drawings are merely schematic illustrations of embodiments of the present application, in which like reference numerals denote like or similar parts, and a repetitive description thereof will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in software, or in a number of hardware modules or integrated circuits, or in different networks and/or processor devices and/or microcontroller devices.
The following describes illustrative embodiments of the present application in detail with reference to the accompanying drawings.
As shown in fig. 1, fig. 1 is a schematic engineering configuration diagram of a dual-core asymmetric phase-shifting transformer CT, which is applicable to the present application, because of the limitation of the phase-shifting transformer structure, only the "primary system side current CT1 of the series transformer, primary load side current CT2 of the series transformer, primary side current CT3 of the exciting transformer, and secondary side phase-modulating winding N current CT4 of the exciting transformer" can be configured, while both ends loops of the "secondary side winding of the series transformer, and secondary side voltage-regulating winding M of the exciting transformer" are installed in the box, so that the CT cannot be installed, and the differential protection engineering implementation of the dual-core asymmetric phase-shifting transformer needs to be implemented based on the CT configuration.
As shown in figure 1, after the secondary side winding current of the series transformer is connected with the N current of the secondary side phase modulation winding of the exciting transformer through the corner joint, the corner joint wiring mode is Y/Y/delta-9 type. Based on ampere-turn balance relation, the series variable longitudinal differential protection which is formed by fixing Y/Y/delta-9 in a wiring mode by adopting a primary system side current CT1 of a series transformer, a primary load side current CT2 of the series transformer and a secondary side phase modulation winding N current CT4 of an exciting transformer can be mainly used for protecting phase-shifting transformer outgoing lines, interphase faults, grounding faults and winding turn-to-turn faults of the series transformer. The Y-side current correction formula is as follows, by adopting a mode of carrying out phase correction on the Y-side current of the primary system side current CT1 of the series transformer and the primary load side current CT2 of the series transformer
Wherein:the secondary current is Y-side CT;/>the phase currents after the Y-side correction are used.
Based on kirchhoff's law, primary winding differential protection consisting of primary system side current CT1 of a series transformer, primary load side current CT2 of a series transformer and primary side current CT3 of an exciting transformer can be adopted, and the primary winding differential protection is mainly used for improving the sensitivity of ground faults of leads and primary winding parts in the installation range of CT. The winding differential protection is not affected by excitation inrush current, but does not protect winding turn-to-turn faults.
As shown in fig. 1, besides the longitudinal differential protection and the phase-shift primary winding differential protection of the series transformer mentioned above, the phase-shift transformer should be further provided with an excitation transformer split-phase differential protection based on ampere turn balance relationship, which is composed of an excitation transformer primary side current CT3, an excitation transformer secondary side phase modulation winding N current CT4 and an excitation transformer secondary side voltage modulation winding M current, and is mainly used for protecting interphase faults, ground faults and winding turn-to-turn faults of the excitation transformer.
As shown in FIG. 1, after the current of the secondary side voltage regulating winding M of the exciting transformer is connected with the current of the secondary side voltage regulating winding N of the exciting transformer through the angle joint, the angle joint wiring mode is Y/Y/delta-9 type. Based on ampere-turn balance relation, the exciting transformer primary side current CT3, exciting transformer secondary side phase modulation winding N current CT4 (phase modulation winding N star-shaped wiring current) and exciting transformer secondary side phase modulation winding N current CT4 (current after the voltage modulation winding M angle wiring) can be adopted to form an exciting variation longitudinal differential protection which is fixed to be Y/Y/delta-9 in a wiring mode, and the exciting variation longitudinal differential protection is mainly used for protecting interphase faults, grounding faults and winding inter-turn faults of the exciting transformer. The phase correction method is to perform phase correction on the primary side current CT3 of the exciting transformer and the Y side current of the secondary side phase modulation winding N current CT4 (phase modulation winding N star-shaped wiring current) of the exciting transformer, wherein the Y side current correction formula is as follows:
wherein:the secondary current is Y-side CT; />The phase currents after the Y-side correction are used.
The turns ratio of the primary and secondary windings of the conventional transformer is fixed. The technical engineering difficulties faced by the excitation variation longitudinal differential protection of the phase-shifting transformer are as follows: the secondary side voltage regulating winding M and the secondary side phase regulating winding N of the exciting transformer are used for realizing respective voltage regulating and phase regulating functions, and the regulating tap of the secondary winding is dynamically regulated in two directions and in a full range, so that the turns ratio of the primary side and the secondary side in the working process of the exciting transformer is not fixed, and a conventional fixed coefficient cannot be provided for differential flow calculation.
Aiming at the difficulty in the implementation of the longitudinal differential protection engineering of the exciting transformer, the application discloses an exciting differential protection method of a double-core asymmetric phase-shifting transformer based on the intelligent following principle of turns ratio.
As shown in fig. 2, fig. 2 is a flowchart of a method for protecting the excitation variation of a dual-core asymmetric phase-shifting transformer according to the present application. In this embodiment, the excitation variation differential protection method for the dual-core asymmetric phase-shifting transformer includes the following steps:
step one: and collecting secondary current data as current excitation quantity of differential protection, carrying out phase correction on the secondary current of the star-shaped wiring according to the collected secondary current data, and calculating corrected secondary current data.
Further, in the present embodiment, the phase correction is: the star connection is changed into the angle connection or the angle connection is changed into the star connection.
Further, in this embodiment, the secondary current data includes: the secondary current of the primary side current CT3 of the exciting transformer and the secondary current of the secondary side phase modulation winding N current CT4 of the exciting transformer.
In the application of transformer differential protection, in order to simplify field wiring, each side CT of the transformer adopts a star-type wiring mode, the polarity ends of the CT point to the same direction (such as the bus side), and the secondary currents of the CT on each side are directly connected into the protection. At this time, for the transformer in the Y/-11 wiring mode, a phase difference of 30 degrees occurs between the secondary currents at two sides, and the protection device needs to correct the phase through a software algorithm. The protection device mainly has two phase correction modes: triangle-type lateral star-type side correction (i.e., Δ→ Y) and star-type lateral triangle-type side correction (i.e., y→Δ). The star-side-to-triangle-type side correction (i.e., y→Δ) is used in this example.
The Y→delta phase correction algorithm is as follows:
the correction formula of the secondary current of the primary side current CT3 of the exciting transformer is as follows:
wherein:a secondary current of CT3 of the primary side is changed for the excitation; />And correcting the secondary current of each phase of the excitation primary side CT 3.
The correction formula of the secondary current of the secondary side phase modulation winding N current CT4 of the exciting transformer is as follows:
wherein:the secondary current of the exciting secondary side phase modulation winding N current CT4 is; /> And correcting the secondary currents of each phase for the exciting-variable secondary side phase modulation winding N current CT 4.
Further, the secondary current after the M-angle wiring of the excitation transformer voltage regulating winding is the secondary current flowing through the N-current CT4 of the excitation transformer secondary side phase regulating windingThe transformer delta side is used as a phase correction reference side and is not used for phase correction.
The purpose of the above steps corrected by the software algorithm is: the phase between the currents on both sides of the differential loop of the transformer is consistent. The formula is divided by the root number III, because the amplitude is three times the original root number except the change of the phase after the two vectors are subtracted, and the amplitude is the same as the original current after the root number III is divided, so that the purpose of unchanged amplitude after the phase deviation is achieved.
Step two: acquiring equipment parameter data and tap real-time gear data of a device, and performing turns ratio intelligent following calculation according to the acquired data to obtain balance coefficients Kpn and Kpm of each secondary current;
further, in this embodiment, the device parameters include: phase modulation winding N, voltage regulation winding M tap middle gear and corresponding turns ratio; the phase modulation winding N and the voltage regulation winding M have a percentage of turns per gear; the capacity and rated voltage of the nameplate of the transformer; and the primary side current CT3 transformation ratio of the exciting transformer and the secondary side phase modulation winding N current CT4 transformation ratio of the exciting transformer.
Further, in this embodiment, the current gear of the tap is the current gear of the tap of the phase modulation winding N and the voltage regulation winding M.
Factors influencing differential protection differential flow calculation of the transformer: the transformer is mainly unbalanced caused by the mismatch of high-low voltage side current transformers of the transformer, and the transformer has a standard transformation ratio, and the rated current of the transformer is an irregular number although the transformer has a standard capacity, so the influence of the transformer on a differential current is not considered in the selection of the current transformer. In the embodiment, unbalance caused by different current amplitudes at the high and low voltage sides and mismatching of the current transformers at the high and low voltage sides is eliminated by referring to the balance coefficient.
The concept of the balance coefficient is: the proportionality coefficient used when two different units or the same unit and the reference different amounts are calculated to the same unit or the same reference is the balance coefficient.
Further, in this embodiment, the calculation formula of the real-time balance coefficient Kpn of the secondary current of the exciting-variable secondary side phase modulation N winding CT4 is as follows:
Kpn＝Pn*(1+Rn*(Dn-On))*K4/K3
wherein: pn is the turns ratio corresponding to the tap middle gear of the phase modulation winding N; rn is the percentage of turns per gear of the phase modulation winding N; the Dn is the current gear of the phase modulation winding N tap, and the On is the middle gear of the phase modulation winding N tap; k3 is the transformation ratio of the primary side current CT3 of the exciting transformer; and K4 is the transformation ratio of the current CT4 of the secondary side phase modulation winding N of the exciting transformer.
Further, in this embodiment, the calculation formula of the real-time balance coefficient Kpm of the secondary current after the angular connection of the exciting-variable secondary side voltage regulating winding M is as follows:
Kpm＝Pm*(1+Rm*(Dm-Om))*K4/K3
wherein: pm is the turns ratio corresponding to the tap middle gear of the voltage regulating winding M; rm is the percentage of turns per gear of the voltage regulating winding M; the current gear of the tap of the voltage-regulating winding M is Dm, and the middle gear of the tap of the voltage-regulating winding M is Om; k3 is the transformation ratio of the primary side current CT3 of the exciting transformer; and K4 is the transformation ratio of the current CT4 of the secondary side phase modulation winding N of the exciting transformer.
Further, as a reference side for the balance coefficient calculation, the primary side current CT3 secondary current of the exciting transformer is not subjected to amplitude compensation, i.e., the balance coefficient is 1.
Step three: calculating differential current and braking current of the excitation variable differential protection according to the calculated corrected secondary current data and balance coefficients Kpn and Kpm of each secondary current, and if coordinates of the differential current and the braking current are in a differential proportion action area and no other locking condition exists, performing differential protection action;
further, in the present embodiment, the calculation formulas of the differential current and the braking current are as follows:
wherein:each phase secondary current after the primary side current CT3 of the exciting transformer is subjected to phase correction; />Phase correction is carried out on the phase-corrected secondary currents of each phase of the N current CT4 of the excitation variable secondary side phase modulation winding; />Each phase of secondary current after the excitation transformer voltage regulating winding M angle type wiring, namely each phase of secondary current flowing through the excitation transformer secondary side phase regulating N winding CT 4; i dz For said differential current; i zd For the braking current.
Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.
Claims (7)
1. An excitation variation protection method for a double-core asymmetric phase-shifting transformer comprises the following steps:
collecting secondary current data as current excitation quantity of differential protection, carrying out phase correction on secondary current of star-shaped or angle-shaped wiring according to the collected secondary current data, and calculating corrected secondary current data;
acquiring equipment parameter data and tap real-time gear data of a device, and performing turns ratio intelligent following calculation according to the acquired data to obtain balance coefficients Kpn and Kpm of each secondary current;
calculating differential current and braking current of the excitation variable differential protection according to the calculated corrected secondary current data and balance coefficients Kpn and Kpm of each secondary current, and if coordinates of the differential current and the braking current are in a differential proportion action area and no other locking condition exists, performing differential protection action;
the phase correction is: the star-shaped wiring is changed into the angle-shaped wiring, or the angle-shaped wiring is changed into the star-shaped wiring;
the excitation variation protection method for the double-core asymmetric phase-shifting transformer is adaptive to the double-core asymmetric phase-shifting transformer, and the double-core asymmetric phase-shifting transformer is provided with: primary system side current CT1 of the series transformer, primary load side current CT2 of the series transformer, primary side current CT3 of the exciting transformer, secondary side phase modulation winding N current CT4 of the exciting transformer, secondary side winding of the series transformer and secondary side voltage modulation winding M of the exciting transformer;
the differential current and the braking current are calculated as follows:
wherein:each phase secondary current after the primary side current CT3 of the exciting transformer is subjected to phase correction; />Phase correcting the N current CT4 of the secondary side phase modulation winding of the exciting transformerSecondary current of each phase; />Each phase of secondary current after the excitation transformer voltage regulating winding M angle type wiring, namely each phase of secondary current flowing through the excitation transformer secondary side phase regulating N winding CT 4; i dz For said differential current; i zd For the braking current.
2. The excitation variation protection method for a dual-core asymmetric phase-shifting transformer according to claim 1, wherein the secondary current data includes: the secondary current of the primary side current CT3 of the exciting transformer and the secondary current of the secondary side phase modulation winding N current CT4 of the exciting transformer.
3. The excitation variation protection method for a dual-core asymmetric phase-shifting transformer according to claim 1, wherein the device parameters include: phase modulation winding N, voltage regulation winding M tap middle gear and corresponding turns ratio; the phase modulation winding N and the voltage regulation winding M have a percentage of turns per gear; the capacity and rated voltage of the nameplate of the transformer; and the primary side current CT3 transformation ratio of the exciting transformer and the secondary side phase modulation winding N current CT4 transformation ratio of the exciting transformer.
4. The excitation variation protection method for a dual-core asymmetric phase-shifting transformer according to claim 1, wherein the current gear of the tap is: the current gear of the phase modulation winding N tap and the current gear of the voltage regulation winding M tap.
5. A field-weakening protection method for a dual-core asymmetric phase-shifting transformer according to claim 1 or 4, characterized in,
the calculation formula of the real-time balance coefficient Kpn of the secondary current CT4 of the secondary side phase modulation winding of the exciting transformer is as follows:
Kpn＝Pn*(1+Rn*(Dn-On))*K4/K3
wherein: pn is the turns ratio corresponding to the tap middle gear of the phase modulation winding N; rn is the percentage of turns per gear of the phase modulation winding N; dn is the current gear of the phase modulation winding N tap; on is the middle gear of the phase modulation winding N tap; k3 is the transformation ratio of the primary side current CT3 of the exciting transformer; and K4 is the transformation ratio of the current CT4 of the secondary side phase modulation winding N of the exciting transformer.
6. A method for protecting a double-core asymmetric phase-shifting transformer from excitation variation according to claim 1, 3 or 4,
the calculation formula of the real-time balance coefficient Kpm of the secondary current after the excitation secondary side voltage regulating winding M angle type wiring is as follows:
Kpm＝Pm*(1+Rm*(Dm-Om))*K4/K3
wherein: pm is the turns ratio corresponding to the tap middle gear of the voltage regulating winding M; rm is the percentage of turns per gear of the voltage regulating winding M; the current gear of the winding tap of the Dm voltage-regulating winding M; om is the middle gear of the tap of the voltage regulating winding M; k3 is the transformation ratio of the primary side current CT3 of the exciting transformer; and K4 is the transformation ratio of the current CT4 of the secondary side phase modulation winding N of the exciting transformer.
7. The excitation variation protection method for a two-core asymmetric phase-shifting transformer according to claim 1, wherein the primary side current CT3 secondary current balance coefficient of the excitation transformer is 1 as a reference side for balance coefficient calculation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210028950.XA CN114362101B (en) | 2022-01-11 | 2022-01-11 | Excitation variation protection method for double-core asymmetric phase-shifting transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210028950.XA CN114362101B (en) | 2022-01-11 | 2022-01-11 | Excitation variation protection method for double-core asymmetric phase-shifting transformer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114362101A CN114362101A (en) | 2022-04-15 |
| CN114362101B true CN114362101B (en) | 2023-11-17 |
Family
ID=81109655
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210028950.XA Active CN114362101B (en) | 2022-01-11 | 2022-01-11 | Excitation variation protection method for double-core asymmetric phase-shifting transformer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114362101B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202840481U (en) * | 2012-11-02 | 2013-03-27 | 东方日立(成都)电控设备有限公司 | Differential protector of phase-shifting transformer |
| CN105186452A (en) * | 2015-09-10 | 2015-12-23 | 南京国电南自电网自动化有限公司 | Implementation method for phase-shifting transformer differential protection |
| CN108551156A (en) * | 2018-05-08 | 2018-09-18 | 南京南瑞继保电气有限公司 | Adjustable transformer differential protecting method, device, system and computer storage media |
| CN113241727A (en) * | 2021-05-26 | 2021-08-10 | 广东电网有限责任公司 | Ampere-turn balance differential protection method and system for phase-shifting transformer |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8553379B2 (en) * | 2009-09-17 | 2013-10-08 | Schweitzer Engineering Laboratories Inc | Transformer differential protection |
-
2022
- 2022-01-11 CN CN202210028950.XA patent/CN114362101B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202840481U (en) * | 2012-11-02 | 2013-03-27 | 东方日立(成都)电控设备有限公司 | Differential protector of phase-shifting transformer |
| CN105186452A (en) * | 2015-09-10 | 2015-12-23 | 南京国电南自电网自动化有限公司 | Implementation method for phase-shifting transformer differential protection |
| CN108551156A (en) * | 2018-05-08 | 2018-09-18 | 南京南瑞继保电气有限公司 | Adjustable transformer differential protecting method, device, system and computer storage media |
| CN113241727A (en) * | 2021-05-26 | 2021-08-10 | 广东电网有限责任公司 | Ampere-turn balance differential protection method and system for phase-shifting transformer |
Non-Patent Citations (1)
| Title |
|---|
| 典型移相变压器差动保护配置对比分析;张晓宇;顾乔根;文继锋;莫品豪;郑超;;江苏电机工程(01);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114362101A (en) | 2022-04-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7629786B2 (en) | Device for reducing harmonics in three-phase poly-wire power lines | |
| Emanuel | Apparent power definitions for three-phase systems | |
| EP2888639B1 (en) | Distribution transformer | |
| CN107733244B (en) | Power electronic transformer with arc suppression coil and control method thereof | |
| Chiesa et al. | Calculation of inrush currents–Benchmarking of transformer models | |
| Marx et al. | An introduction to symmetrical components, system modeling and fault calculation | |
| CN114362101B (en) | Excitation variation protection method for double-core asymmetric phase-shifting transformer | |
| KR101655415B1 (en) | Hybrid transformer with high-efficiency energy-saving | |
| JPH09135570A (en) | Multiple rectifier | |
| Dahl | Electric circuits: theory and applications | |
| Jordi et al. | Steinmetz system design under unbalanced conditions | |
| JP5033898B2 (en) | Power receiving equipment | |
| Bellan et al. | Circuit representation of voltage unbalance emission due to line asymmetry | |
| US11056883B1 (en) | System and method for implementing a zero-sequence current filter for a three-phase power system | |
| WO2006068495A2 (en) | Device for reducing harmonics | |
| KR101447703B1 (en) | Broadband passive harmonic filter Reduced Harmonic of Three-phase six-pulse. | |
| KR100534144B1 (en) | a device of decreasing harmonic with keep improve the balance of voltage and current | |
| Kasztenny et al. | Operate and restraint signals of a transformer differential relay | |
| Solak et al. | Modeling and analysis of the single-core phase shifting transformer and its differential protection | |
| KR101783239B1 (en) | Hybrid power quality improving device with high-efficiency energy-saving | |
| CN115602430B (en) | Harmonic suppression device and method based on iron core magnetization compensation | |
| JP2006271026A (en) | Leakage current suppression circuit | |
| Di Perna et al. | Static series compensator for voltage dip mitigation with zero-sequence injection capability | |
| JPWO2019207640A1 (en) | Power converter and constant acquisition method | |
| KR101655436B1 (en) | Hybrid transformer with high-efficiency energy-saving |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |