CN112039033B - Method for resisting power frequency magnetic field interference for line protection device - Google Patents

Method for resisting power frequency magnetic field interference for line protection device Download PDF

Info

Publication number
CN112039033B
CN112039033B CN202010738193.6A CN202010738193A CN112039033B CN 112039033 B CN112039033 B CN 112039033B CN 202010738193 A CN202010738193 A CN 202010738193A CN 112039033 B CN112039033 B CN 112039033B
Authority
CN
China
Prior art keywords
current
power frequency
magnetic field
frequency magnetic
self
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
Application number
CN202010738193.6A
Other languages
Chinese (zh)
Other versions
CN112039033A (en
Inventor
朱建红
张毅
石文国
饶剑波
徐秦
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jicheng Software Co ltd
Original Assignee
Jicheng Software Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Jicheng Software Co ltd filed Critical Jicheng Software Co ltd
Priority to CN202010738193.6A priority Critical patent/CN112039033B/en
Publication of CN112039033A publication Critical patent/CN112039033A/en
Application granted granted Critical
Publication of CN112039033B publication Critical patent/CN112039033B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H1/00—Details of emergency protective circuit arrangements
    • H02H1/0007—Details of emergency protective circuit arrangements concerning the detecting means
    • 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
    • H02H7/22—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 for distribution gear, e.g. bus-bar systems; for switching devices
    • 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
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/40—Arrangements for reducing harmonics

Landscapes

  • Emergency Protection Circuit Devices (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)

Abstract

The invention discloses a method for resisting power frequency magnetic field interference for a line protection device, which comprises the following steps: adjusting the input polarity of the primary side of the current transformer to be inverted by 180 degrees, and simultaneously inverting the lines of the secondary side PCB of the current transformer by 180 degrees; the protection device obtains a corresponding external wiring form according to the self matching information; for the line differential protection of double-bus connection, the current I generated by the interference of power frequency magnetic field is calculated*For the line differential protection of 3/2 wiring, current generated by power frequency magnetic field interference can be filtered after the wiring of the mutual inductor is adjusted; for double-bus line protection, comparing current I generated by power frequency magnetic field interference*And threshold
Figure DDA0002605868350000011
Size of (1), if
Figure DDA0002605868350000012
Then do not proceed with the treatment if
Figure DDA0002605868350000013
Correcting each vector value; and respectively correcting each current vector value to obtain a corrected current vector value. The circuit protection device can filter power frequency interference signals under the wiring of the double bus 3/2, so that protection maloperation caused by power frequency interference is avoided.

Description

Method for resisting power frequency magnetic field interference for line protection device
Technical Field
The invention relates to the technical field of power system relay protection, in particular to a method for resisting power frequency magnetic field interference for a circuit protection device.
Background
Power frequency magnetic field disturbance is the most common type of electromagnetic disturbance, and a magnetic field is associated with places where current flows. The frequency of the power frequency magnetic field in China is 50 Hz. Under normal conditions, the steady magnetic field generated by the power frequency current is relatively small, but under heavy load or fault conditions, the magnetic field associated with the current is relatively large. Under the effect of the power frequency magnetic field, a power frequency interference current I with similar direction and amplitude is induced on each Current Transformer (CT) of the relay protection device, the interference signal and a channel normal signal I are mixed together and transmitted to the protection device, and the influence on the protection device is as follows: for the protection functions (such as split-phase differential and overcurrent) adopting a single current channel, only one path of protection current is involved in logic operation, and the interference current is small, so that the protection function is basically not influenced; for the protection function (such as pilot homodyne protection) adopting multiple current channels, the number of current channels participating in logic operation is large, and the interference current superposed by each channel is correspondingly large. When the interference current exceeds the zero-difference threshold, the protection device may malfunction.
In order to reduce the influence of power frequency interference on the protection device, patent 1 (patent No. CN108963984A) adopts measures of adjusting the polarity of the external terminal of the ac plug-in for bus protection and performing parity reversal inside software, but this method needs to control the internal parity serial number by a program to restore the normal signal, which undoubtedly increases the complexity of the program; patent 2 (patent No. CN106055757A) proposes to design appropriate PCB wiring to reduce the power frequency impact, but does not deal with the algorithm inside the protection device. Different from the bus protection applied in patent 1, the high-voltage line protection needs to support two wiring modes of double buses and 3/2 on site, and the influence of power frequency interference under the 2 wiring modes is different.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a method for resisting power frequency magnetic field interference for a line protection device, which can filter power frequency interference signals of the line protection device under double bus and 3/2 wiring, thereby avoiding protection maloperation caused by power frequency interference.
In order to solve the technical problem, the invention provides a method for resisting power frequency magnetic field interference for a line protection device, which comprises the following steps:
(1) adjusting the Current Transformer A1、01、B2、C2The input polarity of the primary side is inverted by 180 degrees, and simultaneously, the lines of the secondary side PCB of the current transformer are also processed The inverse value is 180 degrees, the correctness of the normal external current direction is ensured after the treatment, and the 180 degrees inverse value is carried out on the current generated by the interference of the power frequency magnetic field; wherein, A1、B1、C1、01Respectively a first group of A, B, C phases and an external zero sequence CT, A2、B2、C2、02The two-phase bus-bar protection circuit is respectively a second group of A, B, C phases and an external zero sequence CT, only the first group of CT is used for double-bus wiring line protection, and two groups of CT are used for 3/2 wiring line protection;
(2) the primary wiring form is double-bus wiring or 3/2 wiring, and the protection device obtains a corresponding external wiring form according to self matching information;
(3) for the line differential protection of double-bus connection, the current I generated by the interference of power frequency magnetic field is calculated*(ii) a For the line differential protection of 3/2 wiring, current generated by power frequency magnetic field interference can be filtered after the wiring of the mutual inductor is adjusted; wherein, I*The current generated by a single CT under the interference of a power frequency magnetic field;
Figure BDA0002605868330000021
a current threshold for determining power frequency interference;
(4) for double-bus line protection, comparing current I generated by power frequency magnetic field interference*And threshold
Figure BDA0002605868330000022
Size of (1), if
Figure BDA0002605868330000023
Then no processing is performed; if it is
Figure BDA0002605868330000024
Correcting each vector value;
(5) and respectively correcting each current vector value to obtain a corrected current vector value.
Preferably, in the step (3), for the line differential protection of the double-bus connection, the current I generated by the power frequency magnetic field interference is calculated*The method comprises the following specific steps: for double-bus wiringLine protection, because only one group of CT is used, the zero sequence current 3I is produced by itself0 self-production＝Ia1+Ib1+Ic1Therefore, the A-phase and external zero-sequence current transformer is adjusted, the input polarity of the primary side of the A-phase and the lines of the secondary side PCB are subjected to 180-degree reverse processing, the current generated by the adjusted current transformer under the interference of the power frequency magnetic field and the current generated by the current transformer which is not adjusted under the interference of the power frequency magnetic field have 180-degree approximate difference, and thus, the power frequency magnetic field current can be partially offset on hardware, the self-produced zero-degree current generated by the interference of the power frequency magnetic field is reduced, and the direction of the normal current is not influenced;
self-produced zero sequence current 3I calculated by device during non-power frequency magnetic field interference0 self-productionComprises the following steps:
3I0 self-production＝Ia1+Ib1+Ic1 (1)
Self-produced zero sequence current calculated by device during power frequency magnetic field interference
Figure BDA0002605868330000025
Comprises the following steps:
Figure BDA0002605868330000026
external zero sequence current when power frequency magnetic field is interfered
Figure BDA0002605868330000031
Comprises the following steps:
Figure BDA0002605868330000032
due to 3I0 external connectionAnd 3I0 self-productionThe self-produced zero-sequence current calculated for the external connection and the device under normal conditions, therefore 3I0 external connection＝3I0 self-production
Figure BDA0002605868330000033
For the line differential protection of 3/2 wiring, the current that can filter power frequency magnetic field after adjusting the mutual-inductor wiring and disturb and produce specifically is: for line protection of 3/2 line connection, since two sets of CT are used, the self-generated zero sequence current calculated by the device is 3I 0 self-production＝Ia1+Ib1+Ic1+Ia2+Ib2+Ic2Therefore, the A phase of the first group of CT, the external zero sequence current transformer and the B, C phase current transformer of the second group of CT are adjusted, the input polarity of the primary side and the lines of the secondary side PCB are all processed by 180 degrees, and the specific principle is adjusted to protect the double-bus wiring line;
3/2 wiring line protection device-calculated self-generated zero sequence current under power frequency magnetic field interference
Figure BDA0002605868330000034
Comprises the following steps:
Figure BDA0002605868330000035
in the above formula 3I01 self-production、3I02 self-productionLine protection of 3/2 connections for the calculated self-generated zero sequence currents of the first and second CT sets, 3I0 self-productionSelf-generated zero sequence current calculated for 3/2 wired line protection total device;
line protection for double bus wiring, 3I0 external connectionAnd
Figure BDA0002605868330000036
power frequency magnetic field interference current 2X I approximately two times different*Calculating power frequency magnetic field interference current I*(ii) a For line protection of 3/2 wiring, current generated by power frequency magnetic field interference is filtered through processing of a current transformer, and 3I0 external connectionAnd
Figure BDA0002605868330000037
approximately equal.
The invention has the beneficial effects that: the invention can effectively filter the current generated by the power frequency magnetic field interference, is beneficial to ensuring that differential protection does not generate misoperation due to the power frequency magnetic field interference, and ensures the stability of the protection function, thereby realizing effective cooperation between different levels of protection and being beneficial to the stability of a system.
Drawings
Fig. 1 is a schematic diagram of a hardware structure according to the present invention.
FIG. 2 is a schematic flow chart of the method of the present invention.
Detailed Description
As shown in FIG. 1, the primary and secondary terminals of some transformers are cross-connected, so that the unregulated transformer induces I + I current*The current induced by the adjusted mutual inductor is I-I*. The above processing not only maintains the polarity of the normal current, but also can make the interference signals of some channels reverse polarity, and when the channels participate in the operation, most interference signals can be counteracted.
As shown in fig. 2, a method for protecting a line protection device against power frequency magnetic field interference includes the following steps:
(1) adjusting the Current Transformer A1、01、B2、C2The input polarity of the primary side is inverted by 180 degrees, meanwhile, the lines of the PCB on the secondary side of the current transformer are also inverted by 180 degrees, the correctness of the normal external current direction is ensured after the processing, and simultaneously, the 180 degrees inversion is carried out on the current generated by the interference of the power frequency magnetic field;
(2) the primary wiring form is double-bus wiring or 3/2 wiring, and the protection device obtains a corresponding external wiring form according to self matching information;
(3) for the line differential protection of double-bus connection, the current I generated by the interference of power frequency magnetic field is calculated *(ii) a For the line differential protection of 3/2 wiring, current generated by power frequency magnetic field interference can be filtered after the wiring of the mutual inductor is adjusted;
(4) for double-bus line protection, comparing current I generated by power frequency magnetic field interference*And threshold
Figure BDA0002605868330000041
Size of (2)If, if
Figure BDA0002605868330000042
Then no processing is performed; if it is
Figure BDA0002605868330000043
Correcting each current vector value;
(5) and respectively correcting each current vector value to obtain a corrected current vector value.
In the step (3), for the line differential protection of the double-bus wiring, the current I generated by the power frequency magnetic field interference is calculated*The method specifically comprises the following steps: for the line protection of double-bus wiring, because only one group of CT is used, the self-generated zero-sequence current 3I0 self-production＝Ia1+Ib1+Ic1Therefore, the A-phase and external zero-sequence current transformer is adjusted, the input polarity of the primary side of the A-phase and the lines of the secondary side PCB are subjected to 180-degree reverse processing, the current generated by the adjusted current transformer under the interference of the power frequency magnetic field and the current generated by the current transformer which is not adjusted under the interference of the power frequency magnetic field have 180-degree approximate difference, and thus, the power frequency magnetic field current can be partially offset on hardware, the self-produced zero-degree current generated by the interference of the power frequency magnetic field is reduced, and the direction of the normal current is not influenced;
Self-produced zero sequence current 3I calculated by device during non-power frequency magnetic field interference0 self-productionComprises the following steps:
3I0 self-production＝Ia1+Ib1+Ic1 (1)
Self-produced zero sequence current calculated by device during power frequency magnetic field interference
Figure BDA0002605868330000051
Comprises the following steps:
Figure BDA0002605868330000052
external zero sequence current when power frequency magnetic field is interfered
Figure BDA0002605868330000053
Comprises the following steps:
Figure BDA0002605868330000054
due to 3I0 external connectionAnd 3I0 self-productionThe self-produced zero-sequence current calculated for the external connection and the device under normal conditions, therefore 3I0 external connection＝3I0 self-production
Figure BDA0002605868330000055
For the line differential protection of 3/2 wiring, the current that can filter power frequency magnetic field after adjusting the mutual-inductor wiring and disturb and produce specifically is: for line protection of 3/2 line connection, since two sets of CT are used, the self-generated zero sequence current calculated by the device is 3I0 self-production＝Ia1+Ib1+Ic1+Ia2+Ib2+Ic2Therefore, the A phase of the first group of CT, the external zero sequence current transformer and the B, C phase current transformer of the second group of CT are adjusted, the input polarity of the primary side and the lines of the secondary side PCB are all processed by 180 degrees, and the specific principle is adjusted to protect the double-bus wiring line;
3/2 wiring line protection device-calculated self-generated zero sequence current under power frequency magnetic field interference
Figure BDA0002605868330000056
Comprises the following steps:
Figure BDA0002605868330000057
in the above formula 3I01 self-production、3I02 self-productionLine protection of 3/2 connections for the calculated self-generated zero sequence currents of the first and second CT sets, 3I0 self-productionSelf-generated zero sequence current calculated for 3/2 wired line protection total device;
Line protection for double bus wiring, 3I0 external connectionAnd
Figure BDA0002605868330000061
power frequency magnetic field interference current 2 xI approximately differing by two times*Calculating the power frequency magnetic field interference current I*(ii) a For line protection of 3/2 wiring, current generated by power frequency magnetic field interference is filtered through processing of a current transformer, and 3I0 external connectionAnd
Figure BDA0002605868330000062
approximately equal.
For the line differential protection of double-bus connection, the current generated by approximately twice power frequency magnetic field interference is calculated according to the formulas (1), (2), (3) and (4), so that the power frequency magnetic field interference current I is calculated*For line protection of 3/2 wiring, current generated by power frequency magnetic field interference can be filtered by the device according to a formula (5) after the wiring of the mutual inductor is adjusted.
The invention effectively filters the current generated by the power frequency magnetic field interference, is beneficial to ensuring that differential protection does not generate misoperation due to the power frequency magnetic field interference, and ensures the stability of the protection function, thereby realizing effective cooperation between different levels of protection and being beneficial to the stability of a system.

Claims (2)

1. A method for resisting power frequency magnetic field interference for a line protection device is characterized by comprising the following steps:
(1) adjusting the Current Transformer A1、01、B2、C2The input polarity of the primary side is inverted by 180 degrees, meanwhile, the lines of the PCB on the secondary side of the current transformer are also inverted by 180 degrees, the correctness of the normal external current direction is ensured after the processing, and simultaneously, the 180 degrees inversion is carried out on the current generated by the interference of the power frequency magnetic field; wherein A is 1、B1、C1、01Respectively a first group of A, B, C phase current transformers CT and an external zero sequence current transformer CT, A2、B2、C2、02A second group of A, B, C phases and an external zero sequence current transformer CT respectively, and only uses for protecting double-bus wiring linesTo the first group of current transformers CT, two groups of current transformers CT are used for 3/2 wiring line protection;
(2) the primary wiring form is double-bus wiring or 3/2 wiring, and the protection device obtains a corresponding external wiring form according to self matching information;
(3) for the line differential protection of double-bus connection, the current I generated by the interference of power frequency magnetic field is calculated*(ii) a For the line differential protection of 3/2 wiring, current generated by power frequency magnetic field interference can be filtered after the wiring of the mutual inductor is adjusted; wherein, I*The current generated by a single current transformer CT when the power frequency magnetic field is interfered;
Figure FDA0003557960850000011
a current threshold for determining power frequency interference;
(4) for double-bus line protection, comparing current I generated by power frequency magnetic field interference*And threshold
Figure FDA0003557960850000012
Size of (1), if
Figure FDA0003557960850000013
Then no processing is performed; if it is
Figure FDA0003557960850000014
Correcting each vector value;
(5) and respectively correcting each current vector value to obtain the corrected current vector value.
2. The method according to claim 1, wherein in step (3), the current I generated by the power frequency magnetic field interference is calculated for the line differential protection of the double bus connection *The method specifically comprises the following steps: for the line protection of double-bus wiring, only one set of current transformer CT is used to produce zero sequence current 3I0 self-production＝Ia1+Ib1+Ic1Adjusting A phase and external zero sequence current transformer to makeThe primary side input polarity and the line of the secondary side PCB are processed for 180 degrees in a reverse mode, the current generated by the adjusted current transformer under the interference of the power frequency magnetic field approximately differs from the current angle generated by the current transformer which is not adjusted under the interference of the power frequency magnetic field by 180 degrees, the power frequency magnetic field current is partially offset on hardware, the self-generated zero sequence current generated by the interference of the power frequency magnetic field is reduced, and the direction of the normal current is not influenced;
self-produced zero sequence current 3I calculated by device during non-power frequency magnetic field interference0 self-productionComprises the following steps:
3I0 self-production＝Ia1+Ib1+Ic1 (1)
Self-produced zero sequence current calculated by device during power frequency magnetic field interference
Figure FDA0003557960850000021
Comprises the following steps:
Figure FDA0003557960850000022
external zero sequence current when power frequency magnetic field is interfered
Figure FDA0003557960850000023
Comprises the following steps:
Figure FDA0003557960850000024
due to 3I0 external connectionAnd 3I0 self-productionFor both the normally-connected zero-sequence current and the self-generated zero-sequence current calculated by the apparatus, thus 3I0 external connection＝3I0 self-production
Figure FDA0003557960850000025
For 3/2 wiring line differential protection, the adjustment of the transformer wiring can be filteredThe current generated by the power frequency magnetic field interference is specifically as follows: for line protection of 3/2 line connection, two sets of current transformers CT are used, and the self-generated zero sequence current calculated by the device is 3I 0 self-production＝Ia1+Ib1+Ic1+Ia2+Ib2+Ic2Adjusting the A phase of the first group of current transformers CT, the external zero sequence current transformers and the B, C phase current transformers of the second group of current transformers CT to enable lines of the primary side input polarity and the secondary side PCB to be subjected to reverse 180-degree processing, and adjusting the specific principle to protect the lines with double-bus wiring lines;
3/2 wiring line protection device-calculated self-generated zero sequence current under power frequency magnetic field interference
Figure FDA0003557960850000026
Comprises the following steps:
Figure FDA0003557960850000027
in the above formula 3I01 self-production、3I02 self-productionLine protection of 3/2 connections for respectively calculated self-generated zero sequence currents of first and second groups of current transformer CT devices, 3I0 self-productionSelf-generated zero sequence current calculated for 3/2 wired line protection total device;
for line protection of the double bus bar connection,
Figure FDA0003557960850000028
and
Figure FDA0003557960850000029
power frequency magnetic field interference current 2X I approximately two times different*Calculating power frequency magnetic field interference current I*(ii) a For line protection of 3/2 wiring, the current generated by power frequency magnetic field interference is filtered through the processing of the current transformer,
Figure FDA00035579608500000210
and
Figure FDA00035579608500000211
approximately equal.
CN202010738193.6A 2020-07-28 2020-07-28 Method for resisting power frequency magnetic field interference for line protection device Active CN112039033B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010738193.6A CN112039033B (en) 2020-07-28 2020-07-28 Method for resisting power frequency magnetic field interference for line protection device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010738193.6A CN112039033B (en) 2020-07-28 2020-07-28 Method for resisting power frequency magnetic field interference for line protection device

Publications (2)

Publication Number Publication Date
CN112039033A CN112039033A (en) 2020-12-04
CN112039033B true CN112039033B (en) 2022-05-31

Family

ID=73583352

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010738193.6A Active CN112039033B (en) 2020-07-28 2020-07-28 Method for resisting power frequency magnetic field interference for line protection device

Country Status (1)

Country Link
CN (1) CN112039033B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113517676B (en) * 2021-05-06 2022-10-28 东方电子股份有限公司 Method for preventing power frequency magnetic field from interfering bus differential protection under slight fault situation

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1045101A (en) * 1963-03-11 1966-10-05 Parsons C A & Co Ltd Apparatus for the detection or measurement of electrical discharges or other disturbances
CN108963984A (en) * 2018-06-15 2018-12-07 许继集团有限公司 Prevent method, device for preventing unwanted operation and the protection system of site bus protection malfunction
CN109143143A (en) * 2018-10-19 2019-01-04 天生桥二级水力发电有限公司天生桥水力发电总厂 Transformer substation current transformer secondary side polarity intelligent detection device and method
CN110690687A (en) * 2019-11-08 2020-01-14 许昌许继软件技术有限公司 Protection method of differential circuit

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU2016401814A1 (en) * 2016-04-07 2018-10-25 Soltec Energías Renovables, S.L. Installation for powering auxiliary equipment in electrical energy generation plants

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1045101A (en) * 1963-03-11 1966-10-05 Parsons C A & Co Ltd Apparatus for the detection or measurement of electrical discharges or other disturbances
CN108963984A (en) * 2018-06-15 2018-12-07 许继集团有限公司 Prevent method, device for preventing unwanted operation and the protection system of site bus protection malfunction
CN109143143A (en) * 2018-10-19 2019-01-04 天生桥二级水力发电有限公司天生桥水力发电总厂 Transformer substation current transformer secondary side polarity intelligent detection device and method
CN110690687A (en) * 2019-11-08 2020-01-14 许昌许继软件技术有限公司 Protection method of differential circuit

Also Published As

Publication number Publication date
CN112039033A (en) 2020-12-04

Similar Documents

Publication Publication Date Title
US10530146B2 (en) Differential protection method and differential protection device for performing a differential protection method
Li et al. Single-phase-to-ground fault section location in flexible resonant grounding distribution networks using soft open points
CN112039033B (en) Method for resisting power frequency magnetic field interference for line protection device
CN103474974A (en) Distribution network single-phase ground protection method based on zero-sequence current sudden change straight line fitting direction
CN107315128A (en) A kind of distributed earthing wire-selecting method and system based on GOOSE
CN108963984B (en) Prevent method, device for preventing unwanted operation and the protection system of site bus protection malfunction
Sidhu et al. A power transformer protection technique with stability during current transformer saturation and ratio-mismatch conditions
JP2009198442A (en) Voltage abnormality detection device and voltage protection relay device
CN111562424A (en) Voltage sag source identification method and system considering transformer propagation characteristics
CN115800234A (en) Power distribution network fault arc extinction system and method based on serial connection voltage division of H-bridge converter and arc extinction coil
CN109921403B (en) Controllable current source earth fault full compensation method without inductance compensation
Etingov et al. Development of restraint algorithm for improvement of reliability of transformer differential protection during external short circuits
Bujanovic et al. Adaptive algorithm for microprocessor based distance relays in smart grid
CN103490384B (en) Multi-generator ship intermediate voltage electric power system protection method and device
CN105977914B (en) The method and device of transformer zero-sequencedirectional protection under interior bridge mode
JP2017112741A (en) Ground fault protection system
Guangfu et al. The influence of low resistance grounding system in delta side of transformer on differential protection and its solutions
JP2016010223A (en) Current differential relay device
Valov et al. Implementation and Dynamic Validation of an Adaptive Protection System during Microgrid Restoration
Silva et al. HVDC Converter Transformers Protection-Part 1: Signal Processing Aspects
CN215419588U (en) Nuclear power plant power consumption system neutral point non-effective grounding system
Borscevskis et al. Directional earthfault protection operation and setup aspects in medium voltage compensated network
JP2010166784A (en) Different-line different-phase cross through current transformer and line selecting relay device
Ismail et al. Elimination of Zero Sequence Currents Effect on Differential Protection For Power Transformers Connected to Power Grid
Solak et al. Differential protection of single-core symmetrical phase shifting transformers

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