CN111948491A - Transient signal-based active power distribution network multi-terminal quantity fault identification method and system - Google Patents

Transient signal-based active power distribution network multi-terminal quantity fault identification method and system Download PDF

Info

Publication number
CN111948491A
CN111948491A CN202010806360.6A CN202010806360A CN111948491A CN 111948491 A CN111948491 A CN 111948491A CN 202010806360 A CN202010806360 A CN 202010806360A CN 111948491 A CN111948491 A CN 111948491A
Authority
CN
China
Prior art keywords
fault
transient
voltage
bus
phase
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.)
Granted
Application number
CN202010806360.6A
Other languages
Chinese (zh)
Other versions
CN111948491B (en
Inventor
孙良志
郭学林
邹贵彬
贾玭
王文东
苑源
任鹏飞
蒋立潇
郭久红
洪亚
李敬东
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.)
State Grid Corp of China SGCC
Liaocheng Power Supply Co of State Grid Shandong Electric Power Co Ltd
Original Assignee
State Grid Corp of China SGCC
Liaocheng Power Supply Co of State Grid Shandong Electric Power 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 State Grid Corp of China SGCC, Liaocheng Power Supply Co of State Grid Shandong Electric Power Co Ltd filed Critical State Grid Corp of China SGCC
Priority to CN202010806360.6A priority Critical patent/CN111948491B/en
Publication of CN111948491A publication Critical patent/CN111948491A/en
Application granted granted Critical
Publication of CN111948491B publication Critical patent/CN111948491B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
    • 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
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/085—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution lines, e.g. overhead
    • 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
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/088—Aspects of digital computing
    • 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
    • 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
    • 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
    • H02H7/28—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 for meshed systems

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Emergency Protection Circuit Devices (AREA)
  • Locating Faults (AREA)

Abstract

The disclosure provides a transient signal-based active power distribution network multi-terminal quantity fault identification method and a system, wherein firstly, a transient voltage is adopted to construct a protection starting criterion; comparing the integral average value of the zero-mode voltage in the protection time window with the zero-mode setting threshold value, judging whether the ground fault occurs, comparing the integral average value of each phase of transient voltage in the protection time window after the zero-mode component is filtered with the set threshold value, and identifying the fault phase; then according to the fault phase and the fault type, selecting a corresponding transient signal to carry out windowed Fourier transform, extracting the voltage and the current of a corresponding characteristic frequency band, calculating the transient impedance under the required characteristic frequency band, and judging the fault direction by comparing the root mean square value of the transient impedance with the magnitude of a protection setting impedance value; and finally, judging the fault position according to the multi-terminal fault direction information. The method disclosed by the invention is basically not influenced by factors such as transition resistance, DG permeability, network running state and the like, has low requirements on communication conditions, and can realize fault identification and comprehensive protection of the active power distribution network.

Description

Transient signal-based active power distribution network multi-terminal quantity fault identification method and system
Technical Field
The disclosure relates to the technical field of active power distribution network fault identification, in particular to a transient signal-based active power distribution network multi-terminal quantity fault identification method and system.
Background
The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.
With more and more Distributed Generation (DG) directly connected to the power distribution network, the concept of an active power distribution network is proposed in the 2008 international large power grid Conference (CIGRE), and the active power distribution network has the advantages of capability of fully consuming renewable energy, low line loss, flexibility and reliability in power supply and the like, and is considered to be the development direction of the intelligent power distribution network. However, access to DG presents new challenges to distribution network relay protection. Because the traditional power distribution network is usually in a single-power radial topology, simple and feasible three-section type overcurrent protection is widely applied. However, the access of the DGs increases the power supply in the power distribution network, and influences the magnitude and direction of fault current, so that tide current does not flow in a single direction when the active power distribution network is in fault, and the fault characteristics of the active power distribution network are obviously different from those of the traditional power distribution network. Therefore, if the active power distribution network still adopts the original relay protection theory, the phenomenon of false operation or failure operation of protection may be caused.
In order to meet the protection requirement of an active power distribution network, in recent years, scholars at home and abroad carry out a great deal of research in the field, and the proposed solutions can be mainly divided into three categories: firstly, when a fault occurs, the DG quits operation, and then the fault position is determined by using a traditional protection method; secondly, identifying a fault section by utilizing improved single-ended quantity protection based on local information; and thirdly, fault identification and positioning are carried out by utilizing multi-terminal information.
The inventors have found that the existing methods have various problems:
for the first method, the topological structure of the active power distribution network is changed into a traditional single-power radial structure after the DG is cut off, the protection device judges the fault position according to the fault characteristics after the DG is cut off, so that a fault line is cut off, and the DG is controlled to be connected to the grid after the fault is eliminated. The scheme does not need to change the original protection method, but the power supply reliability is low, and the stability of the power system is influenced by frequent switching of DGs. In addition, the applicability of the original protection method can also be ensured by limiting the position and the capacity of the DG access, so that the traditional distribution network protection method can correctly act under the condition of not cutting off the DG, but the flexibility and the economy of the DG grid connection are seriously limited by the method. For the second method, on the basis of current protection, the fixed value of current protection is adaptively adjusted according to the topological structure and the operation mode of the power distribution network, and the method can only be applied to an active power distribution network under a specific operation condition. With the gradual increase of the permeability of the DG in the power distribution network, the limitation of the single-terminal-quantity protection scheme will be larger and larger. For the third method, the current differential protection is affected by data or equipment synchronization, and the current power distribution network does not have an additional synchronous data channel or GPS equipment; if the pilot protection method based on the positive sequence current mutation phase is adopted, the method firstly judges the fault direction by utilizing the phase characteristics of the positive sequence current mutation, then the protection devices at two sides mutually send fault direction information, and when the devices at two sides of a certain section judge that the forward fault occurs, the section is considered as a fault section. The method does not need strict time synchronization, but under the condition of large fault resistance and load, a fault line may have a through current, so that the accuracy of fault direction judgment is influenced.
Disclosure of Invention
The method and the system are used for identifying the fault direction by using the transient signal of the measuring point, then determining the fault section by comparing the multi-end fault direction, reducing the influence of factors such as transition resistance, DG permeability, network running state and the like in the fault judgment process, having low requirement on communication conditions and realizing the fault identification of a feeder line, a bus and a branch line of the active power distribution network.
In order to achieve the purpose, the following technical scheme is adopted in the disclosure:
one or more embodiments provide a transient signal-based active power distribution network multi-terminal fault identification method, which includes the following steps:
acquiring bus transient voltage of each measuring point and three-phase current of each incoming and outgoing line of the bus;
for each measuring point, identifying a fault phase and a fault type according to the transient voltage of the bus;
calculating transient impedance and judging based on the transient voltage and current signals of each measuring point to obtain the fault direction of each measuring point;
and fusing the fault directions of the measurement points to determine a fault section.
One or more embodiments provide a transient signal-based active power distribution network multi-terminal fault identification system, which includes a protection device disposed at each wire inlet and outlet of a bus, where the protection device executes the transient signal-based active power distribution network multi-terminal fault identification method.
One or more embodiments provide a transient signal based active power distribution network multi-terminal fault identification system, comprising:
an acquisition module: the bus transient voltage acquisition device is configured to be used for acquiring bus transient voltage of each measurement point and three-phase current of each incoming and outgoing line of the bus;
the fault phase and fault type judging module: configured for identifying, for each measurement point, a faulty phase and a fault type from the bus transient voltage;
a fault direction identification module: the transient voltage and current signal of each measuring point is used for calculating transient impedance and judging to obtain the fault direction of each measuring point;
a comparison and identification module: configured for fusing the fault directions of the measurement points to determine a fault section.
An electronic device comprising a memory and a processor and computer instructions stored on the memory and executed on the processor, the computer instructions, when executed by the processor, performing the steps of the above method.
A computer readable storage medium storing computer instructions which, when executed by a processor, perform the steps of the above method.
Compared with the prior art, the beneficial effect of this disclosure is:
(1) the fault direction judgment of each measuring point only needs the fault information of the local measuring point, the communication requirement on the protection device arranged at each measuring point is low, and strict data synchronization is not required. Meanwhile, the fault direction is judged based on the high-frequency impedance at the protection back side, the physical significance is clear, and the fault judgment accuracy is improved.
(2) The method utilizes the transient signal to construct a protection criterion, and has high sensitivity and transition resistance.
(3) The transient fault direction signal is utilized to realize the comprehensive protection of the feeder line, the bus and the branch line in the active power distribution network.
(4) The protection devices only need to transmit logic signals representing fault directions, and strict time synchronization is not needed, so that the cost of the protection devices is reduced, and the protection devices have better economy.
Drawings
The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and not to limit the disclosure.
FIG. 1 is a flow chart of a method of embodiment 1 of the disclosure;
fig. 2 is a schematic diagram of an active power distribution network model of embodiment 1 of the present disclosure;
fig. 3 is a schematic diagram of an active power distribution network fault attachment network according to embodiment 1 of the present disclosure;
fig. 4 is a schematic structural diagram of an inverter-type distributed power supply according to embodiment 1 of the present disclosure;
fig. 5 is a schematic diagram of amplitude-frequency characteristics of transient impedances measured when forward and reverse faults occur in each protection device of the simulation example in embodiment 1 of the present disclosure;
fig. 6 is a diagram of transient voltage phase selection results of a simulation example of embodiment 1 of the present disclosure under different types of faults.
The specific implementation mode is as follows:
the present disclosure is further described with reference to the following drawings and examples.
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise. It should be noted that, in the case of no conflict, the embodiments and features in the embodiments in the present disclosure may be combined with each other. The embodiments will be described in detail below with reference to the accompanying drawings.
Example 1
In the technical solution disclosed in one or more embodiments, as shown in fig. 1, the method for identifying a multi-terminal fault of an active power distribution network based on a transient signal includes the following steps:
step 1, obtaining bus transient voltage of each measuring point and three-phase current of each incoming and outgoing line of a bus;
step 2, identifying a fault phase and a fault type according to the transient voltage of the bus aiming at each measuring point;
step 3, calculating and judging transient impedance based on the transient voltage and current signals of each measuring point to obtain the fault direction of each measuring point;
and 4, fusing the fault directions of the measurement points to determine a fault section.
In this embodiment, the transient signal of each measurement point is used to determine the fault direction based on each measurement point, and the fault direction determination of each measurement point only requires the fault information of the local measurement point, so that the communication requirement on the protection device arranged at each measurement point is low, and strict synchronization of data is not required. Meanwhile, the fault direction is judged based on the high-frequency impedance at the protection back side, the physical significance is clear, and the fault judgment accuracy is improved.
Step 1, obtaining the bus transient voltage of each measuring point and the three-phase current of each incoming and outgoing line of the bus, installing a protection device on each incoming and outgoing line of the bus, and collecting the bus voltage and the three-phase current of each incoming and outgoing line in real time, wherein the setting position of each protection device is a measuring point.
The embodiment utilizes the transient signal to construct a protection criterion, and has higher sensitivity and anti-transition resistance capability.
In step 2, the method for identifying the fault phase and the fault type according to the transient voltage of the bus for each measurement point comprises the following steps:
step 21, constructing a starting criterion based on the transient voltage, and starting fault identification when the transient voltage of the bus is higher than a threshold value and reaches a set number of times;
the starting criterion may specifically be:
|Δuk(t)|＝|uk(t)-u(t-T)|>Uset
wherein u isk(t) the sampled values of the k-phase (A, B and C-phase) voltage measured by the protection device at the time t; t represents the fundamental frequency period of the alternating voltage and is 20 ms; Δ uk(t) represents a k-phase transient voltage, which is the difference between the voltage at the time t and the voltage before a period; u shapesetIs a set threshold value for preventing frequent activation of protection due to interference.
Optionally, any one of three consecutive voltage signal sampling points can be set to meet the starting criterion, and then the fault identification protection algorithm is started.
In this embodiment, the transient voltage signal is used to construct a start criterion, which can improve the accuracy of the start timing control, and is specifically described as follows:
when a fault occurs, the voltage of a fault point drops from a normal operation level to a lower level, and a fault additional voltage source U is connected to the fault position according to a fault superposition principlefThis is a step signal, whose expression is shown below:
Figure BDA0002629249360000071
in the formula of U0The initial voltage of the fault point before the fault is shown, and (t) is a unit step signal.
When the active power distribution network breaks down, the protection device can detect the transient voltage, and the transient voltage and the U detected by each protection devicefThere is a positive correlation.
Since the fault additional voltage is a step signal and is a full-band signal, the signal detected by protection contains abundant high-frequency components, and the sudden change amount is large. Therefore, whether a fault occurs can be judged by comparing the magnitude of the transient voltage signal.
Step 22, recording the fault moment, selecting data of a data window with a preset size before and after the fault, and extracting zero-mode voltage and transient voltage of each phase; the window size of the set data window may be 10 ms.
Step 23, identifying the fault type: and calculating an integral average value of the zero-mode voltage in the selected data window, comparing the average value with a zero-mode voltage setting threshold value, judging whether the fault is a ground fault, and obtaining a fault type.
The fault types of this embodiment include an earth fault and a non-earth fault, that is, a three-phase fault, a single-phase fault, an inter-phase fault, and the like, and specifically, the determining method may be as follows:
Figure BDA0002629249360000072
wherein S is0Is the integral average value of the zero mode voltage component in the selected data window; lwIs the data window length; s0,setSetting a threshold value for the zero-mode voltage; u. off0And (t) is the zero-mode voltage value at the time t. The three-phase fault, the single-phase fault and the interphase fault can be combined and judged according to the single-phase fault, and the details are not repeated here.
Wherein a zero-mode voltage component uf0The calculation formula of (c) may be as follows:
Figure BDA0002629249360000081
wherein, Δ ua(t)、△ub(t)、△uc(t) are transient voltages for time t A, B and phase C, respectively.
Nulling mode voltage component u within a guard time windowf0Integral average value S0If the fault is a ground fault, S0Is greater, otherwise S0Close to 0.
Step 24, identifying a fault phase: and filtering zero modulus components of the transient voltages of all phases in the selected data window, calculating integral average values of the transient voltages of all phases after the zero modulus components are filtered, and comparing the integral average values with a set phase voltage threshold value to determine a fault phase.
The fault phase is identified by comparing the integral average value of each phase of transient voltage after zero-modulus component filtering in the set time data window with a set threshold value, and the method specifically comprises the following steps:
Figure BDA0002629249360000082
wherein, Δ uk' (t) is each phase transient voltage after zero modulus component is filtered; skThe integral average value of the corrected k-phase transient voltage in a protection time window is obtained; smax＝max{Sa,Sb,ScThe integral average value of the maximum three-phase transient voltage is obtained; in order to eliminate the influence of single-phase earth fault with small transient quantity, a threshold value S is setset。
When a fault occurs, the transient voltage signals of the fault phase and the non-fault phase have obvious amplitude difference, and therefore the fault phase can be identified. In this embodiment, each phase of transient voltage signal is corrected, and the zero modulus component existing in the three-phase line at the time of the ground fault is subtracted, as follows:
Δuk'(t)＝Δuk(t)-uf0(t)
in the embodiment, the transient voltage signals of each phase are corrected and then judged, so that the sensitivity of fault phase identification can be improved when a ground fault occurs.
In step 3, the method for calculating the transient impedance and judging the fault direction of each measuring point based on the transient voltage and current signals of the measuring points comprises the following steps:
step 31, selecting transient voltage and current signals of corresponding time periods to perform windowed Fourier transform according to the fault phase and the fault type, and extracting the voltage and the current of a set characteristic frequency band;
step 32, calculating the transient impedance of the set characteristic frequency band according to the relation among the voltage, the current and the impedance;
step 33, selecting a frequency domain measurement impedance of a set characteristic frequency band, and calculating to obtain a root mean square value of the transient impedance;
optionally, the set characteristic frequency band in the above step may be in a frequency range of 2-4 kHz.
And step 34, comparing the transient impedance root mean square value with the protection setting impedance value, wherein when the transient impedance root mean square value is between the upper limit and the lower limit of the protection setting impedance value, the fault is a forward fault, and otherwise, the fault is a reverse fault.
Specifically, the fault direction determination may be as follows:
Figure BDA0002629249360000091
wherein Z isi,setSetting a threshold value for protection; k is a radical of1And k2For the reliability factor, 0.7 and 1.3 were taken, respectively. When the protection device judges that a positive direction fault occurs, the direction criterion DiTaking 1; when a reverse direction fault is determined DiTake 0.
Threshold value Zi,setDifferent fixed values are adopted according to different fault types, and when the fault type is a three-phase fault, a single-phase impedance setting value is adopted because the measured impedance is single-phase frequency domain impedance; when the fault type is a two-phase fault, the measured impedance is interphase frequency domain impedance, and an interphase impedance setting value is adopted and is 2 times of single-phase impedance theoretically.
The following describes a method for determining a fault direction by using a root mean square value of frequency domain measured impedance under a plurality of characteristic frequencies, by using a specific example, as follows:
the active distribution network model shown in fig. 2 is used for analysis, the distribution network is connected with two inverter-based DGs (IBDGs), and protection devices and circuit breakers are installed at both ends of a main feeder line and at outlets of branch lines. Respectively at the feed line L12、L23Bus B2Branch line l2Upper set fault f1-f4. According to the superposition principle, a failure-attached network is shown in fig. 3. In FIG. 3, Zs1Representing equivalent impedance of the main power supply of the distribution network, Zs2And Zs3Respectively represent a protection device A6And A3The equivalent impedance of the system; zL12Is a main feedLine L12Impedance of (Z)l2Is a branch line l2The impedance of (a); zeq,IBDGIs the equivalent impedance of the IBDG, ZTRepresenting the impedance of the transformer connected to the IBDG.
The IBDG is the most common DG type in the active power distribution network, and its model structure diagram is shown in fig. 4, and the IBDG is composed of a power supply, a dc side parallel capacitor, an inverter and a filter. In order to identify the fault direction using the transient impedance method, the transient impedance of the IBDG within the active power distribution network needs to be analyzed.
When the distribution network has a short-circuit fault, the fault loop of the IBDG comprises a filter and a direct-current side parallel capacitor. The specific circulation path of the fault current varies to some extent according to the state of the inverter switch, but in the high-frequency transient state field, because the parallel capacitance value of the filter is small, the impedance value expressed by the IBDG is relatively close to the impedance of the capacitor of the filter. Therefore, an equivalent impedance model of the IBDG in the high frequency band can be given, as shown in the following equation.
Figure BDA0002629249360000101
Along with the generation of the voltage transient signal, a current transient signal with a corresponding frequency also appears in the distribution network. In the fault-added circuit, protection AiDetected voltage transient signal DeltaUi(j ω) and a current transient signal Δ Ii(j ω) the following relationship exists:
ΔUi(jω)＝ΔIi(jω)Zeq,i(jω)
in the formula, Zeq,i(j ω) represents the system equivalent impedance behind the protection device i.
The transient impedance measured by the protection device is the ratio of the transient voltage and current signals in the frequency domain. In addition, the protection device should select the transient voltage and current of the corresponding fault phase according to the fault type to calculate the transient impedance. If two-phase short circuit or two-phase short circuit grounding occurs, the protection device should select transient voltages of two fault phases and transient current of any fault phase for calculation, taking the fault phases as a phase B and a phase C as an example, and the calculation expression of the transient impedance is as follows:
Figure BDA0002629249360000111
if a three-phase short-circuit fault occurs, the protection can select the transient voltage and current of any phase to calculate as follows:
Figure BDA0002629249360000112
the relation between the transient impedance measured by the protection device under different types of faults and each measured impedance is researched, and a basis can be provided for judging the fault direction.
When the positive direction of the protection device fails, as shown in fig. 3, a failure point f1To protect A2In the positive direction of the protection A2The measured transient impedance is as follows:
Z2＝|Zs3//(Zl2+ZT+Zeq,IBDG)|
fault point f2To protect A3In the positive direction of the protection A3The measured transient impedance is as follows:
Z3＝|(ZL12+Zs1//Zs2)//(Zl2+ZT+Zeq,IBDG)|
fault point f4To protect A7In the positive direction of the protection A7The measured transient impedance is as follows:
Z7＝|(ZL12+Zs1//Zs2)//Zs3|
when a fault occurs in the opposite direction of the protective device, e.g. fault point f2、f3And f4Are all protection A2In the reverse direction, protection A2The measured transient impedance is as follows:
Z2＝|ZL12+Zs1//Zs2|
fault point f1、f3And f4Are all protection A3In the reverse direction, protection A3The measured transient impedance is as follows:
Z3＝|Zs3|
fault point f1、f2And f3Are all protection A7In the reverse direction, protection A7The measured transient impedance is as follows:
Z7＝|Zl2+ZT+Zeq,IBDG|
the specific parameters of the active distribution network model are respectively substituted into the above formula, and the difference of the transient impedance measured by the protection device in forward and reverse faults is shown in fig. 5. As can be seen from fig. 5, the protection measured transient impedances have significant amplitude differences when the fault direction differs, in particular in the high frequency range. Therefore, the high-frequency amplitude of the transient impedance can be used as a criterion for distinguishing forward and reverse faults.
Step 4, the method for determining the fault section by fusing the fault directions of the multi-end multi-measurement point comprises the following steps: and comparing the fault directions of the measurement points, and judging the faults of the bus, the feeder line and the branch line.
The fault direction of each measuring point can be obtained, the fault direction of each measuring point is compared and judged, and fault identification of the bus, the feeder line and the branch line is further achieved.
The protection devices of the embodiment only need to transmit logic signals representing fault directions, do not need strict time synchronization, reduce the cost of the protection devices and have better economy;
the specific fault judgment method for the bus, the feeder line and the branch line comprises the following steps:
for the fault judgment of the branch line, if the fault direction of the measurement point at the branch line is positive, the branch line has an intra-area fault, specifically:
Figure BDA0002629249360000131
wherein M islFor branch line reasonsCriterion for obstacle recognition, DlIs the recognition result of the fault direction at the outlet of the incoming and outgoing line.
For the fault judgment of the bus, if the protection devices of the measurement points at the inlet and outlet lines in the bus measure reverse faults, the bus is considered to have an intra-area fault, otherwise, the bus is an extra-area fault, and the method specifically comprises the following steps:
Figure BDA0002629249360000132
wherein M isBAs a criterion for bus fault recognition, D1，…，DnIs the direction recognition result of the protection of the outlet of each inlet and outlet wire connected with the bus.
For a single feeder line, if the protection at the two sides of the feeder line detects a forward fault, the feeder line has an in-zone fault, otherwise, the feeder line has an out-of-zone fault, specifically:
Figure BDA0002629249360000133
wherein M isLAs criterion for feeder fault recognition, DxAnd DyAnd identifying the fault direction of the protection at the two ends of the feeder line.
The principle of judging whether the feeder line has a fault or not according to the fault directions at the two ends is as follows: the analysis was performed with the active distribution network model shown in fig. 2, when f1Protection A when point fault occurs1、A2Positive direction faults are judged, so that the feeder line between the positive direction faults and the feeder line between the positive direction faults is subjected to in-zone faults; when f is2Protection A when point fault occurs1Judging the positive direction fault and protecting A2And judging that the direction fault occurs, so that the feeder line between the two does not have an in-zone fault.
The embodiment utilizes the transient fault direction signal to carry out fault identification on the feeder line, the bus and the branch line in the active power distribution network, can accurately identify a fault section, and realizes the comprehensive protection of the active power distribution network.
For the purpose of illustration, a 10kV active power distribution network model is built through PSCAD/EMTDC software, and the method for identifying the multi-terminal fault of the active power distribution network based on the transient signal provided in this embodiment is subjected to simulation verification:
the topology of the simulation model is shown in FIG. 2. Wherein the system reference voltage is 10.5kV, and the transformer capacity is 100 MVA; the two IBDGs are photovoltaic power supplies with capacity of 2 MW; the length of each feeder line is shown in the figure, and the impedance of the feeder line per unit length is Z ═ 0.l7+ j0.34) omega/km; the simulation sampling frequency is set to be 20kHz, and the fault direction identification criterion in the protection scheme adopts 2-4kHz as the characteristic frequency.
In order to verify the proposed fault identification method, various typical faults are set in the simulation model, corresponding fault positions are marked in fig. 2, and the occurrence time of each fault is set to 1 s. Based on the above analysis, and taking a certain threshold value in consideration of the relevant influence factors, the protection device A1、A2、A3And A7Fault direction criterion threshold value Zi,setThe setting value of (Ω) is as follows:
Figure BDA0002629249360000141
the single-phase impedance setting value in the three-phase symmetric fault is given in the formula, and the interphase impedance setting value is 2 times of the single-phase impedance setting value in the three-phase symmetric fault.
2) Simulation analysis
a) And (5) simulating fault phase selection criteria.
At fault point f1Setting different types of metallic faults, fig. 6 shows a protection device a2Detected zero mode voltage and transient voltage (zero mode component filtered) signal of each phase. Table 1 shows protection device A under various faults2The fault phase selection result.
TABLE 1 different failure types A2Fault phase selection result of
Type of failure S0 Sa Sb Sc Fault phase selection discrimination result
BCG 2.73 0.07 4.63 4.58 BCG
BC 0 0.07 4.63 4.59 BC
ABC
0 5.29 5.34 5.32 ABC
As can be seen from the graph and the table, a zero-mode voltage component exists when a ground fault occurs, and a zero-mode voltage component does not exist when a ground fault does not occur; the fault phase transient voltage amplitude is higher, and the non-fault phase transient voltage amplitude is lower. In summary, the basis of the fault phase selection method adopted by the embodiment is accurate, and the fault phase selection method can correctly judge the fault type.
b) And (5) simulating the protection criteria of the feeder line, the bus and the branch line.
At fault point f1And f2Set the feeder faults for different initial conditions, table 2 gives the main feeder L12Two-end protection device A1And A2The protection criterion simulation result; at fault point f3Setting bus faults of different initial conditions, Table 3 shows bus B2Protector A at outlet of each incoming/outgoing line2、A3And A7The simulation operation result of (2); at fault point f4Setting the branch line faults for different initial conditions, table 4 gives the branch line l2Exit protection device A7The simulation run results of (1). RfIndicating a fault transition resistance. The transition resistance and the transient impedance are both in units of Ω in the table.
TABLE 2 feeder line fault protection device A1And A2Simulation result
Figure BDA0002629249360000151
Figure BDA0002629249360000161
TABLE 3 protection device A in case of bus fault2、A3And A7Simulation result
Figure BDA0002629249360000162
Table 4 protective device a in case of a branch line fault7Simulation result
Figure BDA0002629249360000163
Figure BDA0002629249360000171
As can be seen from tables 2 to 4, the setting threshold value of the fault direction identification criterion in this embodiment is reasonable and effective, and protection can accurately identify the fault direction for different types of faults at different positions, and has strong transition resistance. For the fault of the branch line, the protection device in the fault identification method of the embodiment can identify the fault branch line only by acquiring local voltage and current signals; and for the fault occurring on the feeder line or the bus, the fault feeder line or the bus can be correctly identified according to the fault direction information obtained by the corresponding protection device.
The embodiment provides an active power distribution network fault identification and multi-terminal protection method based on transient signals based on active power distribution network fault transient characteristics. Firstly, constructing a protection starting criterion by adopting transient voltage; comparing the integral average value of the zero-mode voltage in the protection time window with the zero-mode setting threshold value, judging whether the ground fault occurs, comparing the integral average value of each phase of transient voltage in the protection time window after the zero-mode component is filtered with the set threshold value, and identifying the fault phase; then according to the fault phase and the fault type, selecting a corresponding transient signal to carry out windowed Fourier transform, extracting the voltage and the current of a corresponding characteristic frequency band, calculating the transient impedance under the required characteristic frequency band, and judging the fault direction by comparing the root mean square value of the transient impedance with the magnitude of a protection setting impedance value; and finally, judging the fault position according to the multi-terminal fault direction information. The PSCAD simulation result shows that when faults of various conditions occur in the active power distribution network, the protection scheme provided by the embodiment can reliably act, and has higher sensitivity and anti-transient resistance capability compared with protection based on steady-state quantity. In addition, strict time synchronization is not needed when the feeder pilot protection is carried out, and the method has good economy.
Example 2
The active power distribution network multi-terminal quantity fault identification system based on transient signals that this embodiment provided includes: the method comprises the steps that protection devices are arranged at each wire inlet and outlet of a bus, the protection devices execute the transient signal-based active power distribution network multi-terminal fault identification method in embodiment 1, the fault direction of the protection devices is identified, fault signals of adjacent protection devices are obtained, and the fault directions of related measurement points are compared to determine whether sections connected with the protection devices have faults or not.
Example 3
The embodiment provides active distribution network multiterminal volume fault recognition system based on transient signal includes:
an acquisition module: the bus transient voltage acquisition device is configured to be used for acquiring bus transient voltage of each measurement point and three-phase current of each incoming and outgoing line of the bus;
the fault phase and fault type judging module: configured for identifying, for each measurement point, a faulty phase and a fault type from the bus transient voltage;
a fault direction identification module: the transient voltage and current signal of each measuring point is used for calculating transient impedance and judging to obtain the fault direction of each measuring point;
a comparison and identification module: configured for fusing the fault directions of the measurement points to determine a fault section.
Example 4
The present embodiment provides an electronic device comprising a memory and a processor, and computer instructions stored on the memory and executed on the processor, wherein the computer instructions, when executed by the processor, perform the steps of the method of embodiment 1.
Example 5
This embodiment provides a computer-readable storage medium storing computer instructions that, when executed by a processor, perform the steps of performing the method of embodiment 1.
The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure, and various modifications and changes may be made to the present disclosure by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.
Although the present disclosure has been described with reference to specific embodiments, it should be understood that the scope of the present disclosure is not limited thereto, and those skilled in the art will appreciate that various modifications and changes can be made without departing from the spirit and scope of the present disclosure.

Claims (10)

1. The transient signal-based active power distribution network multi-terminal quantity fault identification method is characterized by comprising the following steps of:
acquiring bus transient voltage of each measuring point and three-phase current of each incoming and outgoing line of the bus;
for each measuring point, identifying a fault phase and a fault type according to the transient voltage of the bus;
calculating transient impedance and judging based on the transient voltage and current signals of each measuring point to obtain the fault direction of each measuring point;
and fusing the fault directions of the measurement points to determine a fault section.
2. The transient signal-based active power distribution network multi-terminal fault identification method of claim 1, wherein: the method for identifying the fault type according to the transient voltage of the bus aiming at each measuring point comprises the following steps:
constructing a starting criterion based on the transient voltage, and starting fault identification when the transient voltage of the bus is higher than a threshold value and reaches a set number of times;
recording the fault moment, selecting data of a data window with a preset size before and after the fault, and extracting zero-mode voltage and transient voltage of each phase;
identifying the fault type: and calculating an integral average value of the zero-mode voltage in the selected data window, comparing the average value with a zero-mode voltage setting threshold value, judging whether the fault is a ground fault, and obtaining a fault type.
3. The transient signal-based active power distribution network multi-terminal fault identification method of claim 1, wherein: the method for identifying the fault phase according to the transient voltage of the bus for each measuring point comprises the following steps:
constructing a starting criterion based on the transient voltage, and starting fault identification when the transient voltage of the bus is higher than a threshold value and reaches a set number of times;
recording the fault moment, selecting data of a data window with a preset size before and after the fault, and extracting zero-mode voltage and transient voltage of each phase;
identifying a fault phase: and filtering zero modulus components of the transient voltages of all phases in the selected data window, calculating integral average values of the transient voltages of all phases after the zero modulus components are filtered, and comparing the integral average values with a set phase voltage threshold value to determine a fault phase.
4. The transient signal-based active power distribution network multi-terminal fault identification method of claim 1, wherein: the method for calculating transient impedance and judging to obtain the fault direction of each measuring point based on the transient voltage and current signals of each measuring point comprises the following steps:
selecting transient voltage and current signals of corresponding time periods to carry out windowed Fourier transform according to the fault phase and the fault type, and extracting the voltage and the current of a set characteristic frequency band;
calculating transient impedance under a set characteristic frequency band according to the relation among voltage, current and impedance;
selecting frequency domain measurement impedance under a set characteristic frequency band, and calculating to obtain a root mean square value of the transient impedance;
and comparing the root mean square value of the transient impedance with the protection setting impedance value, and determining that the fault is a forward fault when the root mean square value of the transient impedance is between the upper limit and the lower limit of the protection setting value, or determining that the fault is a reverse fault.
5. The transient signal-based active power distribution network multi-terminal fault identification method of claim 1, wherein: the method for determining the fault section by fusing the fault directions of the measurement points comprises the following steps: and comparing and judging the fault directions of the measurement points, and identifying the faults of the branch lines, the buses and the feeder lines respectively.
6. The transient signal-based active power distribution network multi-terminal fault identification method of claim 5, wherein: the method for identifying the faults of the branch line, the bus and the feeder line respectively comprises the following steps:
for the fault judgment of the branch line, if the fault direction of the measuring point is positive, the branch line is in fault;
for the fault judgment of the bus, if the protection devices of the measurement points at the inlet and outlet lines in the bus measure reverse faults, the bus is considered to have an intra-area fault, otherwise, the bus is an extra-area fault;
for a single feeder line, if the protection on the two sides of the feeder line detects a forward fault, the feeder line has an in-zone fault, otherwise, the feeder line has an out-of-zone fault.
7. Active distribution network multiterminal volume fault identification system based on transient state signal, characterized by: the method comprises the steps that a protection device is arranged at each wire inlet and outlet of a bus, and the protection device executes the transient signal-based active power distribution network multi-terminal fault identification method in any one of claims 1 to 6.
8. Active distribution network multiterminal volume fault identification system based on transient state signal, characterized by includes:
an acquisition module: the bus transient voltage acquisition device is configured to be used for acquiring bus transient voltage of each measurement point and three-phase current of each incoming and outgoing line of the bus;
the fault phase and fault type judging module: configured for identifying, for each measurement point, a faulty phase and a fault type from the bus transient voltage;
a fault direction identification module: the transient voltage and current signal of each measuring point is used for calculating transient impedance and judging to obtain the fault direction of each measuring point;
a comparison and identification module: configured for fusing the fault directions of the measurement points to determine a fault section.
9. An electronic device comprising a memory and a processor and computer instructions stored on the memory and executable on the processor, the computer instructions when executed by the processor performing the steps of the method of any of claims 1 to 6.
10. A computer-readable storage medium storing computer instructions which, when executed by a processor, perform the steps of the method of any one of claims 1 to 6.
CN202010806360.6A 2020-08-12 2020-08-12 Transient signal-based active power distribution network multi-terminal quantity fault identification method and system Active CN111948491B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010806360.6A CN111948491B (en) 2020-08-12 2020-08-12 Transient signal-based active power distribution network multi-terminal quantity fault identification method and system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010806360.6A CN111948491B (en) 2020-08-12 2020-08-12 Transient signal-based active power distribution network multi-terminal quantity fault identification method and system

Publications (2)

Publication Number Publication Date
CN111948491A true CN111948491A (en) 2020-11-17
CN111948491B CN111948491B (en) 2022-03-18

Family

ID=73332789

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010806360.6A Active CN111948491B (en) 2020-08-12 2020-08-12 Transient signal-based active power distribution network multi-terminal quantity fault identification method and system

Country Status (1)

Country Link
CN (1) CN111948491B (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112595932A (en) * 2020-12-23 2021-04-02 西安科技大学 Single-pole fault line selection method suitable for medium-voltage direct-current power distribution network
CN113281615A (en) * 2021-05-28 2021-08-20 广西电网有限责任公司电力科学研究院 Active power distribution network line fault characteristic analysis method and storage medium
CN113437734A (en) * 2021-08-30 2021-09-24 国网江西省电力有限公司电力科学研究院 Fault protection method and device suitable for wind power plant output line
CN113922343A (en) * 2021-09-22 2022-01-11 国网河北省电力有限公司电力科学研究院 Power distribution network protection fixed value setting method, terminal equipment and storage medium
CN114552547A (en) * 2022-03-01 2022-05-27 国网宁夏电力有限公司 Method and system for identifying fault property of distribution line connected with distributed power supply

Citations (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101242097A (en) * 2008-03-11 2008-08-13 昆明理工大学 Failure line selection method of small current ground system by using simulation after zero mode current measure
CN102621449A (en) * 2012-03-16 2012-08-01 河南理工大学 Single phase ground fault section locating method in small current grounding system
CN103178507A (en) * 2012-12-06 2013-06-26 郭振威 Transmission line self-adaptive single-end transient protection based on transition resistance and fault angle reductions
CN103245880A (en) * 2013-04-19 2013-08-14 国家电网公司 Small current grounding fault location method utilizing circuit equivalent parameter identification principle
CN104578013A (en) * 2015-01-20 2015-04-29 西安理工大学 Directional protection method for distribution network comprising DFIG based on current frequency difference
CN105811382A (en) * 2016-03-24 2016-07-27 国网山东省电力公司枣庄供电公司 Positive sequence impedance differential protection method with braking characteristic for power distribution network containing inverter-based distributed generation (IBDG)
CN106443330A (en) * 2016-09-07 2017-02-22 中国石油大学(华东) Small current grounding system high-resistance grounding fault line selection method based on comparison between transient projection component amplitude and polar relationship
CN108054736A (en) * 2017-11-27 2018-05-18 山东大学 A kind of multiterminal flexible direct current power grid DC line protection method based on voltage pole ripple
CN108663599A (en) * 2018-05-07 2018-10-16 太原理工大学 Fault line selection method for single-phase-to-ground fault based on transient high-frequency component correlation analysis
CN108663602A (en) * 2018-05-14 2018-10-16 山东大学 Flexible direct current power distribution network monopole failure line selection and Section Location and system
CN109085460A (en) * 2018-07-10 2018-12-25 国网浙江省电力有限公司杭州供电公司 The single-ended diagnostic method of extra high voltage direct current transmission line failure based on transient monitoring
CN109119977A (en) * 2018-09-20 2019-01-01 山东大学 Multiterminal flexible direct current power grid DC line fast protection method and system based on single ended voltage
CN109283432A (en) * 2018-10-10 2019-01-29 珠海许继电气有限公司 A kind of method and device based on spectrum sequence kurtosis analysis fault section location
CN109387728A (en) * 2018-12-21 2019-02-26 云南电网有限责任公司电力科学研究院 A kind of fault line selection method for single-phase-to-ground fault and system
US20190137556A1 (en) * 2015-09-09 2019-05-09 Beijing Inhand Networks Technology Co., Ltd. Method and system for detecting and locating single-phase ground fault on low current grounded power-distribution network
CN109901015A (en) * 2019-03-08 2019-06-18 西安交通大学 Fault line selection method for single-phase-to-ground fault based on Discrete Orthogonal S-transformation and information divergence
CN110221176A (en) * 2019-06-28 2019-09-10 昆明理工大学 A kind of micro-capacitance sensor fault detection method based on juxtaposition differential transformation
CN110297154A (en) * 2019-07-18 2019-10-01 国电南瑞科技股份有限公司 Earth fault line selection method and device based on zero mould current temporary state energy
CN110824294A (en) * 2019-10-18 2020-02-21 济南大学 Flexible direct-current power distribution network bipolar short-circuit fault section identification and distance measurement method
CN110907758A (en) * 2019-12-06 2020-03-24 国电南瑞科技股份有限公司 Small current ground fault line selection method covering CT polarity self-correction
CN110907761A (en) * 2019-12-09 2020-03-24 四川旭华源科技有限公司 Continuous line selection method and system for single-phase earth fault
CN111426908A (en) * 2020-03-31 2020-07-17 国电南瑞科技股份有限公司 Single-phase earth fault protection method, device and system for small current earthing system
CN111521908A (en) * 2020-04-30 2020-08-11 华中科技大学 Alternating current fault positioning method applied to four-end wind power direct current power grid

Patent Citations (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101242097A (en) * 2008-03-11 2008-08-13 昆明理工大学 Failure line selection method of small current ground system by using simulation after zero mode current measure
CN102621449A (en) * 2012-03-16 2012-08-01 河南理工大学 Single phase ground fault section locating method in small current grounding system
CN103178507A (en) * 2012-12-06 2013-06-26 郭振威 Transmission line self-adaptive single-end transient protection based on transition resistance and fault angle reductions
CN103245880A (en) * 2013-04-19 2013-08-14 国家电网公司 Small current grounding fault location method utilizing circuit equivalent parameter identification principle
CN104578013A (en) * 2015-01-20 2015-04-29 西安理工大学 Directional protection method for distribution network comprising DFIG based on current frequency difference
US20190137556A1 (en) * 2015-09-09 2019-05-09 Beijing Inhand Networks Technology Co., Ltd. Method and system for detecting and locating single-phase ground fault on low current grounded power-distribution network
CN105811382A (en) * 2016-03-24 2016-07-27 国网山东省电力公司枣庄供电公司 Positive sequence impedance differential protection method with braking characteristic for power distribution network containing inverter-based distributed generation (IBDG)
CN106443330A (en) * 2016-09-07 2017-02-22 中国石油大学(华东) Small current grounding system high-resistance grounding fault line selection method based on comparison between transient projection component amplitude and polar relationship
CN108054736A (en) * 2017-11-27 2018-05-18 山东大学 A kind of multiterminal flexible direct current power grid DC line protection method based on voltage pole ripple
CN108663599A (en) * 2018-05-07 2018-10-16 太原理工大学 Fault line selection method for single-phase-to-ground fault based on transient high-frequency component correlation analysis
CN108663602A (en) * 2018-05-14 2018-10-16 山东大学 Flexible direct current power distribution network monopole failure line selection and Section Location and system
CN109085460A (en) * 2018-07-10 2018-12-25 国网浙江省电力有限公司杭州供电公司 The single-ended diagnostic method of extra high voltage direct current transmission line failure based on transient monitoring
CN109119977A (en) * 2018-09-20 2019-01-01 山东大学 Multiterminal flexible direct current power grid DC line fast protection method and system based on single ended voltage
CN109283432A (en) * 2018-10-10 2019-01-29 珠海许继电气有限公司 A kind of method and device based on spectrum sequence kurtosis analysis fault section location
CN109387728A (en) * 2018-12-21 2019-02-26 云南电网有限责任公司电力科学研究院 A kind of fault line selection method for single-phase-to-ground fault and system
CN109901015A (en) * 2019-03-08 2019-06-18 西安交通大学 Fault line selection method for single-phase-to-ground fault based on Discrete Orthogonal S-transformation and information divergence
CN110221176A (en) * 2019-06-28 2019-09-10 昆明理工大学 A kind of micro-capacitance sensor fault detection method based on juxtaposition differential transformation
CN110297154A (en) * 2019-07-18 2019-10-01 国电南瑞科技股份有限公司 Earth fault line selection method and device based on zero mould current temporary state energy
CN110824294A (en) * 2019-10-18 2020-02-21 济南大学 Flexible direct-current power distribution network bipolar short-circuit fault section identification and distance measurement method
CN110907758A (en) * 2019-12-06 2020-03-24 国电南瑞科技股份有限公司 Small current ground fault line selection method covering CT polarity self-correction
CN110907761A (en) * 2019-12-09 2020-03-24 四川旭华源科技有限公司 Continuous line selection method and system for single-phase earth fault
CN111426908A (en) * 2020-03-31 2020-07-17 国电南瑞科技股份有限公司 Single-phase earth fault protection method, device and system for small current earthing system
CN111521908A (en) * 2020-04-30 2020-08-11 华中科技大学 Alternating current fault positioning method applied to four-end wind power direct current power grid

Non-Patent Citations (7)

* Cited by examiner, † Cited by third party
Title
HUANG, Q等: "A non-unit line protection scheme for MMC-based multi-terminal HVDC grid", 《INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS》 *
刘剑等: "利用暂态测量阻抗的高压直流线路故障识别方法", 《中国电机工程学报》 *
刘红文等: "高精度配网单相接地故障检测与定位***研发", 《电气技术》 *
王晨清等: "适用于风电接入***的相电压暂态量时域选相新原理", 《电网技术》 *
谢仲润: "交直流混合配电网保护技术研究", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》 *
谢仲润等: "基于真双极的MTDC电网直流线路快速保护", 《中国电机工程学报》 *
贾科等: "柔性直流配网中基于暂态高频阻抗比较的方向纵联保护", 《中国电机工程学报》 *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112595932A (en) * 2020-12-23 2021-04-02 西安科技大学 Single-pole fault line selection method suitable for medium-voltage direct-current power distribution network
CN112595932B (en) * 2020-12-23 2024-03-01 西安科技大学 Monopole fault line selection method suitable for medium-voltage direct-current power distribution network
CN113281615A (en) * 2021-05-28 2021-08-20 广西电网有限责任公司电力科学研究院 Active power distribution network line fault characteristic analysis method and storage medium
CN113437734A (en) * 2021-08-30 2021-09-24 国网江西省电力有限公司电力科学研究院 Fault protection method and device suitable for wind power plant output line
CN113437734B (en) * 2021-08-30 2021-12-31 国网江西省电力有限公司电力科学研究院 Fault protection method and device suitable for wind power plant output line
CN113922343A (en) * 2021-09-22 2022-01-11 国网河北省电力有限公司电力科学研究院 Power distribution network protection fixed value setting method, terminal equipment and storage medium
CN113922343B (en) * 2021-09-22 2023-07-25 国网河北省电力有限公司电力科学研究院 Power distribution network protection fixed value setting method, terminal equipment and storage medium
CN114552547A (en) * 2022-03-01 2022-05-27 国网宁夏电力有限公司 Method and system for identifying fault property of distribution line connected with distributed power supply
CN114552547B (en) * 2022-03-01 2023-07-21 国网宁夏电力有限公司 Distribution line fault property identification method and system for connecting distributed power supply

Also Published As

Publication number Publication date
CN111948491B (en) 2022-03-18

Similar Documents

Publication Publication Date Title
CN111948491B (en) Transient signal-based active power distribution network multi-terminal quantity fault identification method and system
CN111007427B (en) Distribution line single-phase earth fault line selection method and computer readable storage medium
CN108663602B (en) Flexible direct current power distribution network monopole failure line selection and Section Location and system
CN107979075B (en) A kind of multiterminal flexible direct current power grid DC line Non-unit protection method
CN102590703B (en) Single-phase grounding failure route selection method of resonance grounding system based on zero-sequence transient charge
CN101943737A (en) Single-phase earth fault diagnosis method and device
CN114295935B (en) Low-voltage measurement-based low-current system medium-voltage single-phase grounding fault positioning method
CN108872783A (en) Resonant earthed system singlephase earth fault Section Location
CN108196162A (en) The DC distribution net monopolar grounding fault wireline inspection method of model and parameters identification
CN109061397A (en) A kind of line fault area recognizing method
CN107271851B (en) A kind of wide area backup protection method based on differential active power
CN114512966B (en) Pilot protection method and system for direct-current power distribution network based on S-transform frequency domain impedance
Meghwani et al. An on-line fault location technique for DC microgrid using transient measurements
CN109444666B (en) Power distribution network single-phase high-blocking line fault identification method and device
CN112952775B (en) Method for protecting voltage quantity of power distribution network containing distributed photovoltaic power supply
CN109193595B (en) Active power distribution network failure separation method based on current phase comparison
CN113917276B (en) Single-phase grounding short-circuit fault positioning method and system for medium-voltage side small-current system
CN109839570A (en) A kind of multiterminal alternating current-direct current mixing power distribution network direct current high resistive fault detection method and device
Liu et al. A fast protection scheme using fault current characteristics in multi-terminal flexible DC distribution network
Zhang et al. A pilot protection on Hybrid DC line based on correlation coefficient
CN115360683B (en) Protection method for single-phase earth fault of neutral point ungrounded system
Fu et al. Directional pilot protection for flexible DC distribution system based on transient high-frequency impedance
Guo et al. Single Phase Short Circuit Fault Location Method Based on Innovation Graph
Yang et al. Boundary Protection Scheme for HVDC Transmission System
Sun et al. A Unit Protection Scheme Based on Transient Signals for Active Distribution Network

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