CN114884027A - Current differential protection method and system - Google Patents
Current differential protection method and system Download PDFInfo
- Publication number
- CN114884027A CN114884027A CN202111295441.5A CN202111295441A CN114884027A CN 114884027 A CN114884027 A CN 114884027A CN 202111295441 A CN202111295441 A CN 202111295441A CN 114884027 A CN114884027 A CN 114884027A
- Authority
- CN
- China
- Prior art keywords
- current
- action
- phase
- braking
- protection
- 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.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
Abstract
The invention discloses a current differential protection method and a system, comprising: acquiring three-phase current sampling values at two sides of a line; respectively determining the current phasor of each side according to the three-phase current sampling value; respectively determining an action current and a braking current according to the current phasor; and performing differential protection according to the action current and the brake current. The method of the invention calculates the action current and the brake current through the amplitude of the current at two sides of the line after the fault, judges the protection action according to the action current and the brake current, can improve the sensitivity of the current differential protection, ensures the reliability of the current differential protection, and solves the technical problem that the current differential protection can not give consideration to both the sensitivity and the reliability of the protection.
Description
Technical Field
The present invention relates to the field of power system relay protection technology, and more particularly, to a current differential protection method and system.
Background
With the large-scale development of offshore wind power, the flexible direct current system is used for sending out the offshore wind power and connecting the offshore wind power into the onshore alternating current power grid, and the flexible direct current system is a typical scene for sending out the offshore wind power in the future.
The protection principle of the power transmission line mainly adopts current differential protection, and the basic principle is that by utilizing kirchhoff current law, when the internal of the power transmission line is in fault, the differential current is greater than the brake current, so that the protection acts rapidly and the fault is isolated; when the external fault of the power transmission line occurs, the differential current is smaller than the braking current, so that the protection is correct and does not act.
After offshore wind power is sent out flexibly and directly and is connected into an alternating current power grid, when an alternating current transmission line breaks down, a flexible direct current system provides a small short-circuit current, and meanwhile, a control strategy of the flexible direct current system causes negative sequence current after the fault to be inhibited, so that fault characteristics are obviously weakened, the action current of current differential protection is obviously reduced, and when the differential current is smaller than braking current, the current differential protection can be refused to act, and the fault identification capability of the current differential protection of the alternating current line is seriously influenced. The current differential protection improves the protection sensitivity during the fault in a line area by reducing the braking coefficient, but the protection reliability during the fault outside the line area is reduced, so that the protection sensitivity and reliability are difficult to be considered.
Disclosure of Invention
The invention provides a current differential protection method and a current differential protection system, which aim to solve the problem of how to efficiently and sensitively realize current differential protection.
In order to solve the above problem, according to an aspect of the present invention, there is provided a current differential protection method, the method including:
acquiring three-phase current sampling values at two sides of a line;
respectively determining the current phasor of each side according to the three-phase current sampling value;
respectively determining an action current and a braking current according to the current phasor;
and performing differential protection according to the action current and the brake current.
Preferably, the determining the current phasor of each side according to the three-phase current sampling values respectively comprises:
and determining the zero sequence current and/or the phase current of at least one phase on each side through Fourier transformation according to the three-phase current sampling value on each side.
Preferably, wherein said determining the action current and the braking current respectively according to said current phasors comprises:
wherein, I 1 Is an operating current;
and
current phasors at the m side and the n side of the line respectively; i is 2 Is a braking current; k is a radical of 1 Is the braking coefficient;
preferably, wherein the differential protection according to the action current and the braking current comprises:
when the action current is greater than or equal to the braking current, protecting the action; and when the action current is smaller than the brake current, the protection does not act.
According to another aspect of the present invention, there is provided a current differential protection system, the system comprising:
the current sampling value acquisition unit is used for acquiring three-phase current sampling values at two sides of the circuit;
the current phasor determining unit is used for respectively determining the current phasor of each side according to the three-phase current sampling value;
the calculating unit is used for respectively determining the action current and the braking current according to the current phasor;
and the protection unit is used for carrying out differential protection according to the action current and the brake current.
Preferably, the current phasor determining unit determines the current phasor of each side according to the three-phase current sampling values, respectively, and includes:
and determining the zero sequence current and/or the phase current of at least one phase on each side through Fourier transformation according to the three-phase current sampling value on each side.
Preferably, the calculating unit, according to the current phasor, determines the action current and the braking current respectively, and includes:
wherein, I 1 Is an operating current;
and
current phasors at the m side and the n side of the line respectively; i is 2 Is a braking current; k is a radical of 1 Is the braking coefficient;
preferably, the protection unit performs differential protection according to the operation current and the braking current, and includes:
when the action current is greater than or equal to the braking current, protecting the action; and when the action current is smaller than the brake current, the protection does not act.
According to another aspect of the invention, a computer-readable storage medium is provided, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method as described above.
According to another aspect of the present invention, there is provided an electronic apparatus including:
the computer-readable storage medium described above; and
one or more processors to execute the program in the computer-readable storage medium.
The invention provides a current differential protection method and a system, comprising the following steps: acquiring three-phase current sampling values at two sides of a line; respectively determining the current phasor of each side according to the three-phase current sampling value; respectively determining an action current and a braking current according to the current phasor; and performing differential protection according to the action current and the brake current. The method of the invention calculates the action current and the brake current through the amplitude of the current at two sides of the line after the fault, judges the protection action according to the action current and the brake current, can improve the sensitivity of the current differential protection, ensures the reliability of the current differential protection, and solves the technical problem that the current differential protection can not give consideration to both the sensitivity and the reliability of the protection.
Drawings
A more complete understanding of exemplary embodiments of the present invention may be had by reference to the following drawings in which:
FIG. 1 is a flow diagram of a current differential protection method 100 according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of the AC line protection installation of offshore wind power via a flexible direct wind removal system according to an embodiment of the present invention;
FIG. 3 is a flow diagram of adaptive split-phase current differential protection according to an embodiment of the invention;
FIG. 4 is a flow chart of adaptive zero sequence current differential protection according to an embodiment of the present invention
Fig. 5 is a schematic structural diagram of a current differential protection system 500 according to an embodiment of the present invention.
Detailed Description
The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same unit/element is denoted by the same reference numeral.
Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
Fig. 1 is a flow chart of a current differential protection method 100 according to an embodiment of the invention. As shown in fig. 1, the current differential protection method provided in the embodiment of the present invention calculates the action current and the brake current according to the amplitude of the current on both sides of the line after the fault, and determines the protection action according to the action current and the brake current, so as to improve the sensitivity of the current differential protection, ensure the reliability of the current differential protection, and solve the technical problem that the current differential protection cannot give consideration to both the sensitivity and the reliability of the protection. The current differential protection method 100 provided by the embodiment of the invention starts from step 101, and obtains three-phase current sampling values at two sides of a line in step 101.
As shown in fig. 2, in an embodiment of the present invention, protection devices of an ac power transmission line are respectively installed on two sides of a line, and the protection devices respectively collect three-phase currents on two sides of the line through current transformers, acquire three-phase current sampling values, and transmit the three-phase current sampling values on the current side to a protection device on an opposite side of the line. And the protection device on each side can judge whether the protection is operated according to the three-phase current sampling values on the two sides.
In step 102, current phasors of each side are respectively determined according to the three-phase current sampling values.
Preferably, the determining the current phasor of each side according to the three-phase current sampling values respectively comprises:
and determining the zero sequence current and/or the phase current of at least one phase on each side through Fourier transformation according to the three-phase current sampling value on each side.
In the embodiment of the present invention, the current phasor on each side may be zero-sequence current, or may be any phase current.
When the current phasor is the phase current of any phase, the protection device acquires the current sampling value of any phase, and the phase current of any phase can be obtained through Fourier transformation.
When the current phasor is zero-sequence current, the protection device sums the acquired three-phase current sampling values firstly, and then the zero-sequence current can be obtained through Fourier transform.
In step 103, an action current and a brake current are respectively determined according to the current phasors.
Preferably, wherein said determining the action current and the braking current respectively according to said current phasors comprises:
wherein, I 1 Is an operating current;
and
current phasors at the m side and the n side of the line respectively; i is 2 Is a braking current; k is a radical of 1 Is the braking coefficient;
in an embodiment of the invention, the operating current is calculated from the current phasors at both sides of the line as
And
the current phasors for the m-side and n-side of the line, respectively.
When the braking current is calculated according to the current phasors at two sides of the line, the amplitude and the phase of the current phasors at two sides of the line need to be compared, if the amplitude of the current at two sides is equal and the phase difference is 180 degrees, the braking current is
k 1 Is the braking coefficient; if the current amplitudes at the two sides of the circuit are not equal, the amplitude is made larger
Has a current phasor of
The amplitude is smaller
Has a current phasor of
The brake current at this time is calculated by the formula
Wherein the content of the first and second substances,
in step 104, differential protection is performed based on the operating current and the braking current.
Preferably, wherein the differential protection according to the action current and the braking current comprises:
when the action current is greater than or equal to the braking current, protecting the action; and when the action current is smaller than the brake current, the protection does not act.
In the embodiment of the invention, the magnitude of the action current and the braking current is compared, and when the action current is larger than the equal braking current, the action is protected; when the action current is smaller than the braking current, the protection does not act.
In the present invention, a method for performing protection based on a phase current of any one phase is defined as a split-phase adaptive current differential protection method, and in this case, on any one side of a line, if an operating current is equal to or greater than a braking current for any one phase, the protection of any one phase corresponding to the any one side is operated, and on the contrary, the protection of any one phase corresponding to the any one side is not operated.
The flow of the adaptive split-phase current differential protection according to the embodiment of the present invention is shown in fig. 3, and includes:
(1) the protection device of the alternating current transmission line is arranged on two sides (an m side and an n side) of the line, the three-phase currents on two sides of the line are respectively collected by the line through the current transformers, and the sampling value of the three-phase current on the side is sent to the protection device on the opposite side of the line.
(2) The protection device calculates the current phasor of each side through Fourier transformation of the collected three-phase current sampling value, namely, the phase current of each phase at two sides of the circuit is calculated.
(3) For any phase, the current phasor at two sides of the circuit is used to calculate the action current, and the calculation formula of the action current is
In the formula, the first step is that,
respectively, the current phasors (i.e., phase currents) on both sides of any corresponding line.
(4) Calculating braking current by using current phasors at two sides of the circuit, comparing the amplitude and phase of the current phasors at two sides of the circuit, if the amplitude of the current at two sides is equal, the phase difference is 180 degrees, and the braking current is
k 1 Is the braking coefficient; if the current amplitudes at the two sides of the circuit are not equal, the amplitude is made larger
Has a current phasor of
The amplitude is small
Has a current phasor of
If the brake current is calculated by the formula
In the formula, the first step is that,
(5) comparing the magnitude of the action current with the magnitude of the brake current, and protecting the action when the action current is greater than or equal to the brake current; when the action current is smaller than the braking current, the protection does not act.
In the invention, a method for performing protection based on zero sequence current is defined as a zero sequence adaptive current differential protection method, and at the moment, on any side of a line, if the action current is larger than or equal to the brake current, the protection on the any side is operated, otherwise, the protection on the any side is not operated.
Fig. 4 shows a self-adaptive zero-sequence current differential protection process according to an embodiment of the present invention, which includes:
(1) the protection device of the alternating current transmission line is arranged on two sides (an m side and an n side) of the line, the three-phase currents on two sides of the line are respectively collected by the line through the current transformers, and the sampling value of the three-phase current on the side is sent to the protection device on the opposite side of the line.
(2) The protection device respectively sums the collected three-phase current sampling values of each side, and calculates the current phasor of each side through Fourier transform, namely the zero sequence current of each side is obtained through calculation.
(3) Calculating the action current by using the current phasors at two sides of the line, wherein the calculation formula of the action current is
In the formula, the first step is that,
zero sequence currents on two sides of the line are respectively;
(4) calculating brake current by using zero sequence current phasors at two sides of the circuit, comparing the amplitude and phase of the zero sequence current phasors at two sides of the circuit, if the amplitude of the zero sequence current at two sides is equal, the phase difference is 180 degrees, the brake current is
k 1 Is the braking coefficient; if the zero sequence current amplitudes at two sides of the line are not equal, the amplitude is made larger
Has a current phasor of
The amplitude is small
Has a current phasor of
If the brake current is calculated by the formula
In the formula, the first step is that,
(5) comparing the magnitude of the action current with the magnitude of the brake current, and protecting the action when the action current is greater than or equal to the brake current; when the action current is smaller than the braking current, the protection does not act.
The self-adaptive current differential protection provided by the invention can improve the protection sensitivity when the internal fault of the circuit occurs, and simultaneously gives consideration to the protection reliability when the external fault occurs. The performance of the method of the invention is illustrated by comparison with conventional current differential protection criteria and with current differential protection criteria that reduce the braking coefficient.
Split-phase adaptive current differential protection
1) When a fault occurs in the line
The conventional current differential protection criterion is as follows:
the split-phase adaptive current differential protection criterion is as follows:
comparing the two criteria, it can be known that when the circuit is in internal fault, the action current is the same, but the braking current is different, and
therefore, the brake current of the split-phase adaptive current differential protection is reduced and the sensitivity is improved with the same action current.
2) When line external fault occurs
The conventional current differential protection criterion is as follows:
the split-phase adaptive current differential protection criterion is as follows:
comparing the two criteria, it can be known that the action current is the same and the brake current is the same when the circuit is in an external fault, and therefore, the reliability of the split-phase adaptive current differential protection is the same as that of the conventional current differential protection.
In conclusion, the split-phase self-adaptive current differential protection improves the failure capability of internal faults and gives consideration to protection sensitivity and reliability.
(2) Zero sequence adaptive current differential protection
1) When a fault occurs in the line
The conventional zero-sequence current differential protection criterion is as follows:
the zero-sequence adaptive current differential protection criterion is as follows:
comparing the two criteria, when the circuit has internal fault, the action current is the same, but the braking current is different, and
therefore, the brake current of the adaptive split-phase current differential protection is the minimum and the sensitivity is the highest with the same action current.
2) When line external fault occurs
The conventional zero-sequence current differential protection criterion is as follows:
the zero-sequence adaptive current differential protection criterion is as follows:
comparing the two criteria, it can be known that the action current is the same and the braking current is the same when the circuit is in an external fault, and thus the reliability of the self-adaptive current differential protection is the same as that of the conventional current differential protection.
In conclusion, the zero sequence self-adaptive current differential protection provided by the invention improves the failure capability of internal faults and gives consideration to the protection sensitivity and reliability.
Fig. 5 is a schematic diagram of a current differential protection system 500 according to an embodiment of the present invention. As shown in fig. 5, a current differential protection system 500 according to an embodiment of the present invention includes: a current sample value acquisition unit 501, a current phasor determination unit 502, a calculation unit 503, and a protection unit 504.
Preferably, the current sampling value obtaining unit 501 is configured to obtain three-phase current sampling values on two sides of a line.
Preferably, the current phasor determining unit 502 is configured to determine the current phasor of each side according to the three-phase current sampling values.
Preferably, the determining unit 502 for current phasor determines the current phasor of each side according to the three-phase current sampling values, respectively, and includes:
and determining the zero sequence current and/or the phase current of at least one phase on each side through Fourier transformation according to the three-phase current sampling value on each side.
Preferably, the calculating unit 503 is configured to determine the action current and the braking current respectively according to the current phasor.
Preferably, the calculating unit 503, according to the current phasor, respectively determining the action current and the braking current, includes:
wherein, I 1 Is an operating current;
and
current phasors at the m side and the n side of the line respectively; i is 2 Is a braking current; k is a radical of 1 Is the braking coefficient;
preferably, the protection unit 504 is configured to perform differential protection according to the action current and the braking current.
Preferably, the protection unit 504 performs differential protection according to the action current and the braking current, and includes:
when the action current is larger than or equal to the braking current, performing protection action; and when the action current is smaller than the brake current, the protection does not act.
The current differential protection system 500 according to the embodiment of the present invention corresponds to the current differential protection method 100 according to another embodiment of the present invention, and is not described herein again.
The invention provides a computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, implements the steps of any one of the current differential protection methods.
The present invention provides an electronic device, including: the computer-readable storage medium described above; and one or more processors for executing the program in the computer-readable storage medium.
The invention has been described with reference to a few embodiments. However, other embodiments of the invention than the ones disclosed above are equally possible within the scope of these appended patent claims, as these are known to those skilled in the art.
Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the [ device, component, etc ]" are to be interpreted openly as referring to at least one instance of said device, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.
Claims (10)
1. A current differential protection method, the method comprising:
acquiring three-phase current sampling values at two sides of a line;
respectively determining the current phasor of each side according to the three-phase current sampling value;
respectively determining an action current and a braking current according to the current phasor;
and performing differential protection according to the action current and the brake current.
2. The method of claim 1, wherein the determining the current phasor for each side separately from the three-phase current sample values comprises:
and determining the zero sequence current and/or the phase current of at least one phase on each side through Fourier transformation according to the three-phase current sampling value on each side.
3. The method of claim 1, wherein said determining an action current and a braking current, respectively, from said current phasors comprises:
wherein, I 1 Is an operating current;
and
current phasors at the m side and the n side of the line respectively; i is 2 Is a braking current; k is a radical of 1 Is the braking coefficient;
4. the method of claim 1, wherein said differentially protecting based on said actuation current and braking current comprises:
when the action current is greater than or equal to the braking current, protecting the action; and when the action current is smaller than the brake current, the protection does not act.
5. A current differential protection system, the system comprising:
the current sampling value acquisition unit is used for acquiring three-phase current sampling values at two sides of the circuit;
the current phasor determining unit is used for respectively determining the current phasor of each side according to the three-phase current sampling value;
the calculating unit is used for respectively determining the action current and the braking current according to the current phasor;
and the protection unit is used for carrying out differential protection according to the action current and the brake current.
6. The system of claim 5, wherein the current phasor determination unit determines the current phasor for each side from the three-phase current sample values, respectively, comprising:
and determining the zero sequence current and/or the phase current of at least one phase on each side through Fourier transformation according to the three-phase current sampling value on each side.
7. The system of claim 5, wherein the computing unit determines the action current and the braking current, respectively, from the current phasors, comprising:
wherein, I 1 Is an operating current;
and
current phasors at the m side and the n side of the line respectively; i is 2 Is a braking current; k is a radical of formula 1 Is the braking coefficient;
8. the system according to claim 5, wherein the protection unit performs differential protection based on the operation current and the braking current, and comprises:
when the action current is greater than or equal to the braking current, protecting the action; and when the action current is smaller than the brake current, the protection does not act.
9. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 4.
10. An electronic device, comprising:
the computer-readable storage medium recited in claim 9; and
one or more processors to execute the program in the computer-readable storage medium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111295441.5A CN114884027A (en) | 2021-11-03 | 2021-11-03 | Current differential protection method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111295441.5A CN114884027A (en) | 2021-11-03 | 2021-11-03 | Current differential protection method and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114884027A true CN114884027A (en) | 2022-08-09 |
Family
ID=82668279
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111295441.5A Pending CN114884027A (en) | 2021-11-03 | 2021-11-03 | Current differential protection method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114884027A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116845839A (en) * | 2023-07-05 | 2023-10-03 | 国网湖北省电力有限公司超高压公司 | Current differential protection method for new energy output line |
-
2021
- 2021-11-03 CN CN202111295441.5A patent/CN114884027A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116845839A (en) * | 2023-07-05 | 2023-10-03 | 国网湖北省电力有限公司超高压公司 | Current differential protection method for new energy output line |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109286202B (en) | Large-scale inversion type power supply grid-connected tie line current differential protection method, device and system | |
| CN105140893A (en) | Differential protection current transformer (CT) saturation recognition method | |
| US10551425B2 (en) | Method for quickly identifying disconnection of CT in protection of 3/2 connection mode based bus | |
| CN114884027A (en) | Current differential protection method and system | |
| EP3012643B1 (en) | Method and apparatus for identifying causes for cable overcurrent | |
| CN112736845B (en) | CT trailing current identification method and device based on current phase angle difference calculation and failure protection method | |
| CN110912161A (en) | Method for judging open-phase fault of power supply incoming line of traction substation | |
| CN109672154B (en) | Method and device for preventing false operation of non-fault phase saturation differential protection | |
| CN111736107B (en) | CT (computed tomography) disconnection detection method, system and medium based on sequence current phase comparison | |
| CN110445104B (en) | Station domain failure protection method and device | |
| CN110687443B (en) | Primary equipment state discrimination method and system | |
| CN111025080B (en) | Method and system for determining fault line based on station domain information | |
| CN104393579A (en) | Method for overcoming influence of outgoing current on busbar differential protection | |
| CN113708343B (en) | Stator grounding protection method and device for salient pole generator and electronic equipment | |
| de Alencar et al. | Power transformer differential protection through gradient of the differential current | |
| CN111537911B (en) | Zero-sequence impedance-based reactor turn-to-turn short circuit fault identification method and system | |
| CN114966323A (en) | Fault identification method and system based on full-time domain mutation information | |
| CN112564065A (en) | Pseudo-synchronous differential protection method and system for direct-current transmission line | |
| CN106410764A (en) | Positive sequence polarization voltage calculating method and device | |
| MX2011013494A (en) | Process for obtaining the blocking of the differential protection against inrush starting currents. | |
| Wijekoon et al. | Transient based faulted conductor selection method for double circuit lines | |
| CN115902336A (en) | Method and system for calculating line capacitive reactance according to compensation voltage | |
| CN111244914B (en) | Line protection method and system suitable for flexible direct access | |
| CN100391073C (en) | Method for realizing digital relay protection anti-time limit characteristic | |
| CN113612190B (en) | Method and system for executing reclosing of alternating current line based on safety margin index |
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 |