CN113093060B - Method, device and equipment for detecting zero line breakage of power distribution network - Google Patents

Method, device and equipment for detecting zero line breakage of power distribution network Download PDF

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CN113093060B
CN113093060B CN202110394950.7A CN202110394950A CN113093060B CN 113093060 B CN113093060 B CN 113093060B CN 202110394950 A CN202110394950 A CN 202110394950A CN 113093060 B CN113093060 B CN 113093060B
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line
current
neutral
effective value
impedance
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CN113093060A (en
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张强
李天友
林智勇
吕志盛
黄超艺
董振业
杨宇辉
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Xiamen University of Technology
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Xiamen University of Technology
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
    • G01R31/54—Testing for continuity
    • 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
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
    • Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
    • Y04S10/52—Outage or fault management, e.g. fault detection or location

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  • General Physics & Mathematics (AREA)
  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)

Abstract

The invention provides a method, a device and equipment for detecting a zero line breaking of a power distribution network, wherein the method comprises the steps of obtaining a neutral line current of a transformer outlet end and a grounding line current; calculating the neutral current to obtain a first effective value of the neutral current and a second effective value of the ground current; and judging whether the neutral is in a disconnection state or not according to the first effective value and the second effective value. The detection equipment is convenient to install, and whether the neutral line has a line break fault can be detected without complex operation.

Description

Method, device and equipment for detecting zero line breakage of power distribution network
Technical Field
The invention relates to the field of power supply detection, in particular to a method, a device and equipment for detecting a zero line breaking of a power distribution network.
Background
When a zero line is broken in a low-voltage distribution network, the load voltage at the downstream of a fault point is too high or too low; but the voltage upstream of the fault point is not affected. The currently known zero-fault detection methods include: (1) based on load side three-phase voltage detection. Patent US20070236845 connects two resistors with large difference to the phase a and neutral and the phase B and neutral respectively, and indicates that the neutral has a disconnection fault when there is different voltage drop on the two resistors. (2) Detection based on zero sequence, negative sequence, harmonic voltage (or current). Patent CN112379218A proposes a method for determining the disconnection of a neutral line based on the unbalance degree of three-phase voltages on the load side, in which the potential of the neutral point of the load shifts after the disconnection of the neutral line, thereby causing the change of the load voltage of each phase, and whether the disconnection fault of the neutral line occurs in the system is determined by detecting the unbalance degree of the negative sequence and zero sequence voltages on the load side. Patent CN201310213280 discloses a method for detecting a broken neutral line based on third harmonic current, which measures the variation of the third harmonic current on three phase lines of power supply output at the same time, and determines the broken neutral line when a set threshold is reached.
Patent US20070236845, patent CN112379218A, need to set up the detection device at each feeder end, the installation is difficult for the equipment quantity. Patent CN201310213280 can provide a detection device on the power supply side, but it is difficult to set a third harmonic detection threshold, and erroneous determination is likely to occur.
In view of this, the present application is presented.
Disclosure of Invention
The invention discloses a method, a device and equipment for detecting a zero line breaking of a power distribution network and a readable storage medium, and aims to overcome the defects in the prior art.
The first embodiment of the invention provides a method for detecting a zero line breaking of a power distribution network, which comprises the following steps:
obtaining neutral line current and grounding line current of a transformer wire outlet section;
operating said neutral current to obtain a first effective value of a neutral current and a second effective value of said ground current;
and judging whether the neutral is in a disconnection state or not according to the first effective value and the second effective value.
Preferably, the grounding impedance of the transformer is 4 Ω -10 Ω, and the equivalent impedance of the multipoint ground of the neutral line is 4 Ω -10 Ω.
Preferably, the impedance of the neutral line is much smaller than the impedance of the transformer to ground, or the equivalent impedance of the neutral line to multipoint ground.
Preferably, the determining whether the neutral is in the disconnection state according to the first effective value and the second effective value specifically includes:
and outputting the neutral line warning information when the second effective value is judged to be larger than the first effective value.
A second embodiment of the present invention provides a zero line breakage detection apparatus for a power distribution network, including:
the current acquisition unit is used for acquiring neutral line current and grounding line current of a transformer wire outlet section;
an operation unit for operating the neutral current to obtain a first effective value of a neutral current and a second effective value of the ground current;
and the judging unit is used for judging whether the neutral is in a disconnection state or not according to the first effective value and the second effective value.
Preferably, the grounding impedance of the transformer is 4 Ω -10 Ω, and the equivalent impedance of the multipoint ground of the neutral line is 4 Ω -10 Ω.
Preferably, the impedance of the neutral line is much smaller than the impedance of the transformer to ground, or the equivalent impedance of the neutral line to multipoint ground.
Preferably, the determining unit is specifically configured to:
and when the second effective value is larger than the first effective value, outputting the neutral line warning information.
A third embodiment of the present invention provides a zero line breakage detection apparatus for a power distribution network, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, where the processor executes the computer program to implement a zero line breakage detection method for a power distribution network as described in any one of the above.
The invention provides a method, a device and equipment for detecting a zero line breaking of a power distribution network.
Drawings
Fig. 1 is a schematic flow chart of a method for detecting a zero line fault of a power distribution network according to a first embodiment of the present invention;
FIG. 2 is a block diagram of a three-phase four-wire system provided by the present invention;
FIG. 3 is an equivalent circuit diagram of a neutral break fault provided by the present invention;
fig. 4 is a schematic diagram of a zero line breakage detection device module of a power distribution network according to a second embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
For better understanding of the technical solutions of the present invention, the following detailed descriptions of the embodiments of the present invention are provided with reference to the accompanying drawings.
The following detailed description of specific embodiments of the invention refers to the accompanying drawings.
The invention discloses a method, a device and equipment for detecting a zero line breaking of a power distribution network, and aims to overcome the defects in the prior art.
Referring to fig. 1, a first embodiment of the present invention provides a method for detecting a zero line fault of a power distribution network, which can be performed by a zero line fault detection device (the following detection device) of the power distribution network, and in particular, by one or more processors in the detection device, so as to implement the following steps:
s101, obtaining neutral line current and grounding line current of a transformer outlet end;
in this embodiment, the detection device may include a terminal with processing capability and a current detection device, such as a current transformer, and it is understood that the current transformer may be sleeved on a neutral line of the outlet terminal of the transformer to collect the current of the neutral line, and the current transformer is configured on the ground line of the transformer to collect the current of the ground line.
S102, calculating the neutral current to obtain a first effective value of the neutral current and a second effective value of the grounding current;
it should be noted that, in this embodiment, since the power distribution network is an alternating current, the measured value is always in a state of periodic change, and the effective value is calculated for detection, and in other embodiments, the effective values of the neutral current and the ground current may also be directly measured by some testing equipment (for example, a power quality analyzer), which is not specifically limited herein, but these schemes are all within the protection scope of the present invention.
And S103, judging whether the neutral is in a disconnection state or not according to the first effective value and the second effective value.
Please refer to fig. 2, in the three-phase four-wire system, UA、UB、UCIs a three-phase power supply, ZA、ZB、ZCIs a three-phase load impedance, ZNIs neutral line impedance, Z1For the grounding impedance of the low-voltage winding of the transformer, Z2Equivalent ground impedance (magnitude and Z) of neutral line multipoint grounding system (namely TN system)1Equivalent), ZNIs much smaller than Z1Or Z2. In the present embodiment, the impedance of the transformer low-voltage winding ground can be 4 Ω -10 Ω, and the equivalent impedance of the neutral line multipoint ground is 4 Ω -10 Ω. In other embodiments, the impedance may correspond to the device according to practical situations, and is not specifically limited herein.
In this embodiment, the impedance of the neutral line is much smaller than the impedance of the transformer to ground, or the equivalent impedance of the neutral line to multipoint ground
Specifically, in the present embodiment, during normal operation of the system, the current I is mainly formed through the neutral line due to asymmetry of the three-phase load and the third harmonic current generated by various non-linear loadsN(ii) a To flow through Z1Current of (I)0Mainly leakage current caused by line distributed capacitance. Therefore, when the neutral line is not broken, the effective value of the current IN>I0。
In the present embodiment, when the neutral line is broken, the equivalent circuit is as shown in fig. 3. The grounding impedances at the two ends of the breaking point are respectively Zjd1,Zjd2It is noted that the ground impedance of a natural ground is typically large when a wire is broken. Whether open-line, ungrounded, open-line, load-side grounded (or power-supply-side grounded), neutral-line branch impedance (Z)N+Zjd1+Zjd2) Will be greater than the impedance (Z) of the ground line branch1+Z2) The current which originally mainly flows through the neutral line turns to flow to the low-voltage side winding of the transformerEarthing terminal Z1At this time I0>IN。
Specifically, in the present embodiment, when it is determined that the second effective value is larger than the first effective value (i.e., when I is greater than the first effective value)0>IN) And outputting the disconnection warning information of the neutral line.
Based on the zero line breaking detection method for the power distribution network, only the neutral line current I of the outlet end of the transformer needs to be detectedNEarth current I of low voltage side winding0The effective value of the central line detecting device is not required to analyze and calculate the positive sequence, the negative sequence, the zero sequence and the harmonic component, so that complex operation is avoided, and the detecting device only needs to be arranged at the power supply side (the wire outlet end of the distribution transformer) to detect whether the whole central line has a broken line fault.
Referring to fig. 4, a second embodiment of the present invention provides a device for detecting a zero line fault of a power distribution network, including:
the current obtaining unit 201 is used for obtaining a neutral line current and a grounding line current of a transformer wire outlet section;
an operation unit 202 for operating the neutral current to obtain a first effective value of a neutral current and a second effective value of the ground current;
a determining unit 203, configured to determine whether the neutral is in a disconnection state according to the first effective value and the second effective value.
Preferably, the ground impedance of the transformer may be 4 Ω -10 Ω, and the equivalent impedance of the neutral line to the multipoint ground may be 4 Ω -10 Ω.
Preferably, the impedance of the neutral line is much smaller than the impedance of the transformer to ground, or the equivalent impedance of the neutral line to multipoint ground.
Preferably, the determining unit is specifically configured to:
and outputting the disconnection warning information of the neutral line when the second effective value is judged to be larger than the first effective value.
A third embodiment of the present invention provides a zero line breakage detection apparatus for a power distribution network, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, where the processor executes the computer program to implement a zero line breakage detection method for a power distribution network as described in any one of the above.
The invention provides a method, a device and equipment for detecting a zero line breaking of a power distribution network.
It should be noted that the above-described embodiments of the apparatus are merely illustrative, and some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. In addition, in the drawings of the embodiment of the apparatus provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, and may be specifically implemented as one or more communication buses or signal lines. One of ordinary skill in the art can understand and implement it without inventive effort.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (7)

1. A method for detecting the zero line breaking of a power distribution network is characterized by being applied to a method for detecting the zero line breaking of a three-phase four-wire system power distribution network; the method comprises the following steps:
obtaining neutral line current and grounding line current of a transformer outlet end;
operating the neutral current to obtain a first effective value of the neutral current and a second effective value of the ground current;
judging whether the neutral line is in a broken line state or not according to the first effective value and the second effective value, and specifically: and outputting the disconnection warning information of the neutral line when the second effective value is judged to be larger than the first effective value.
2. The method according to claim 1, wherein the grounding impedance of the transformer is 4 Ω -10 Ω, and the equivalent impedance of the neutral line to the multipoint ground is 4 Ω -10 Ω.
3. The method of claim 2, wherein the impedance of the neutral line is much smaller than the impedance of the transformer to ground or the equivalent impedance of the neutral line to multipoint ground.
4. The utility model provides a zero line detection device that breaks of distribution network which characterized in that applies to among the zero line detection device of distribution network of three-phase four-wire system, includes:
the current acquisition unit is used for acquiring neutral line current and grounding line current of a transformer outlet end;
an operation unit for operating the neutral current to obtain a first effective value of the neutral current and a second effective value of the ground current;
a determining unit, configured to determine whether the neutral line is in a disconnected state according to the first effective value and the second effective value, and specifically configured to: and outputting the disconnection warning information of the neutral line when the second effective value is judged to be larger than the first effective value.
5. The apparatus of claim 4, wherein the transformer has a ground impedance of 4 Ω -10 Ω, and the neutral line has a multipoint-grounded equivalent impedance of 4 Ω -10 Ω.
6. The apparatus of claim 5, wherein the impedance of the neutral line is substantially less than the impedance of the transformer to ground or the equivalent impedance of the neutral line to multipoint ground.
7. An apparatus for detecting a zero-line fault in a power distribution network, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement a method for detecting a zero-line fault in a power distribution network according to any one of claims 1 to 3.
CN202110394950.7A 2021-04-13 2021-04-13 Method, device and equipment for detecting zero line breakage of power distribution network Active CN113093060B (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101964516A (en) * 2010-10-15 2011-02-02 重庆市电力公司 Three-phase four-wire system zero-line failure and open-phase intelligent protector
CN104158149A (en) * 2014-07-10 2014-11-19 国家电网公司 Intelligent leakage protector provided with broken null line protection function and broken null line protection method
EP2829887A1 (en) * 2013-07-24 2015-01-28 Schneider Electric Industries SAS Method and device for estimating angle of zero-sequence voltage in single-phase earth fault
CN111948575A (en) * 2020-08-04 2020-11-17 中国南方电网有限责任公司超高压输电公司贵阳局 Current transformer secondary side neutral line disconnection detection method and device

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8779776B2 (en) * 2006-11-24 2014-07-15 Jemena Asset Management (6) Pty Ltd Power supply monitoring system
CN103018631A (en) * 2012-12-04 2013-04-03 保定供电公司 System for 10kV fault line detection
CN211478600U (en) * 2019-10-22 2020-09-11 深圳远征技术有限公司 Grounding state detection device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101964516A (en) * 2010-10-15 2011-02-02 重庆市电力公司 Three-phase four-wire system zero-line failure and open-phase intelligent protector
EP2829887A1 (en) * 2013-07-24 2015-01-28 Schneider Electric Industries SAS Method and device for estimating angle of zero-sequence voltage in single-phase earth fault
CN104158149A (en) * 2014-07-10 2014-11-19 国家电网公司 Intelligent leakage protector provided with broken null line protection function and broken null line protection method
CN111948575A (en) * 2020-08-04 2020-11-17 中国南方电网有限责任公司超高压输电公司贵阳局 Current transformer secondary side neutral line disconnection detection method and device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
浅析配电变压器中性点断线的危害及预防;张文勇;《电子制作》;20170201(第4期);第96-97页 *

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