CN112271714B - Arc extinction switching method and system for power distribution network ground fault - Google Patents
Arc extinction switching method and system for power distribution network ground fault Download PDFInfo
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Abstract
The invention discloses a method and a system for arc extinction and switching of a power distribution network ground fault, wherein the method comprises the following steps: injecting a current signal into the power distribution network through the active inverter, and measuring the equivalent parameters of the power distribution network to the ground based on the current signal; measuring the current zero-sequence voltage and the current three-phase voltage of the power distribution network, and judging whether the power distribution network has a ground fault or not based on the current zero-sequence voltage and the current three-phase voltage; if so, obtaining compensation current of each phase by combining equivalent parameters of the power distribution network to the ground, and injecting the compensation current of each phase into the power distribution network based on a current arc extinction method; determining fault phases in the power distribution network, extracting compensation current corresponding to faults from compensation current of each phase, and determining a ground resistance threshold value based on the compensation current; acquiring the actual grounding resistance of a fault phase, and judging whether the actual grounding resistance exceeds a grounding resistance threshold value; and if so, controlling the current phase voltage of the fault phase to be zero based on a voltage arc extinction method. The embodiment of the invention can realize the instant switching of current arc extinction and voltage arc extinction in the operation process, and has good practicability.
Description
Technical Field
The invention relates to the technical field of electric power, in particular to a method and a system for arc extinction and switching of a power distribution network ground fault.
Background
As the power cables and nonlinear loads in the distribution network increase, short-circuit currents, which are generated in case of transient single-phase earth faults, contain a large amount of active components and harmonics in addition to capacitive currents to ground, resulting in that the earth fault arc is difficult to self-extinguish. The arc suppression coil adopted in the traditional mode can only compensate the fundamental wave reactive component of the earth fault current and cannot compensate the active component and harmonic component of the earth fault current no matter a manual tuning mode or an automatic tuning mode is adopted. At present, most of domestic and foreign researches are carried out through active arc extinction by devices such as inverters, and the method can theoretically generate any compensation current including fundamental wave active and reactive currents and harmonic currents of fault currents and can carry out stepless regulation on the output current of the fault currents so as to realize real full compensation. Aiming at different control objects, the active arc extinction method can be divided into two main categories of current arc extinction method and voltage arc extinction method, however, the two categories of arc extinction methods have certain defects in the process of independent use: the current arc extinction method is greatly influenced by the ground parameters, the compensation response time is long, and the voltage arc extinction method needs to preferentially ensure the accuracy of fault phase selection. Therefore, how to make a scheme for extinguishing the arc of the ground fault of the power distribution network according to the advantages of the current arc extinguishing method and the voltage arc extinguishing method is the problem to be solved by the invention.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and provides a power distribution network ground fault arc extinction switching method and system, which can realize the instant switching of a current arc extinction method and a voltage arc extinction method in the operation process, ensure the effective arc extinction of the power distribution network ground fault and have practical value.
In order to solve the problem, the invention provides a power distribution network ground fault arc extinction switching method, which comprises the following steps:
injecting a current signal into the power distribution network through the active inverter, and measuring a ground equivalent parameter of the power distribution network based on the current signal;
measuring the current zero sequence voltage and the current three-phase voltage of the power distribution network, and judging whether the power distribution network has a ground fault or not based on the current zero sequence voltage and the current three-phase voltage;
after the power distribution network is judged to have the ground fault, each phase of compensation current is obtained by combining the ground equivalent parameters of the power distribution network, and each phase of compensation current is injected into the power distribution network based on a current arc extinction method;
determining a fault phase in a power distribution network, extracting compensation current corresponding to the fault phase from the compensation current of each phase, and determining a grounding resistance threshold value based on the compensation current;
acquiring the actual grounding resistance of the fault phase, and judging whether the actual grounding resistance exceeds the grounding resistance threshold value;
and after the actual ground resistance is judged to exceed the ground resistance threshold value, controlling the current phase voltage of the fault phase to be zero based on a voltage arc extinction method.
Optionally, the injecting a current signal into the power distribution network through the active inverter, and measuring the equivalent parameter of the power distribution network to ground based on the current signal includes:
injecting a first current signal into the power distribution network through an active inverter, and acquiring a first zero-sequence voltage at a neutral point of the power distribution network through a voltage transformer to obtain a first relational expression between the first current signal and the first zero-sequence voltage;
injecting a second current signal into the power distribution network through the active inverter, and acquiring a second zero-sequence voltage at a neutral point of the power distribution network through the voltage transformer to obtain a second relational expression between the second current signal and the second zero-sequence voltage;
and performing fusion analysis on the first relational expression and the second relational expression to obtain the equivalent parameters of the distribution network to the ground.
Optionally, the equivalent parameters of the distribution network to ground include a line-to-ground capacitance value and a line-to-ground leakage resistance.
Optionally, after determining whether the power distribution network has an earth fault based on the current zero-sequence voltage and the current three-phase voltage, the method further includes:
and if the power distribution network is judged not to have the ground fault, returning to inject a current signal into the power distribution network through the active inverter.
Optionally, the determining a fault phase in the power distribution network includes:
and based on the current three-phase voltage, performing difference operation on a current voltage value corresponding to each phase of alternating current in the power distribution network and a voltage value at the previous moment, and acquiring a fault phase with a difference value smaller than zero.
Optionally, after determining whether the actual ground resistance exceeds the ground resistance threshold, the method further includes:
and if the actual grounding resistance does not exceed the grounding resistance threshold, returning to inject the compensation current of each phase into the power distribution network based on the current arc extinction.
In addition, an embodiment of the present invention further provides an arc extinction switching system for a power distribution network ground fault, where the system includes:
the parameter measurement module is used for injecting a current signal into the power distribution network through the active inverter and measuring the equivalent ground parameters of the power distribution network based on the current signal;
the fault judgment module is used for measuring the current zero sequence voltage and the current three-phase voltage of the power distribution network and judging whether the power distribution network has a ground fault or not based on the current zero sequence voltage and the current three-phase voltage;
the current control module is used for acquiring each phase of compensation current by combining with the ground equivalent parameters of the power distribution network after judging that the power distribution network has a ground fault, and injecting each phase of compensation current into the power distribution network based on a current arc extinction method;
the threshold value determining module is used for determining fault phases in the power distribution network, extracting compensation current corresponding to the fault phases from the compensation current of each phase, and determining a grounding resistance threshold value based on the compensation current;
the resistance judgment module is used for acquiring the actual grounding resistance of the fault phase and judging whether the actual grounding resistance exceeds the grounding resistance threshold value;
and the voltage control module is used for controlling the current phase voltage of the fault phase to be zero based on a voltage arc extinction method after the actual ground resistance is judged to exceed the ground resistance threshold value.
Optionally, the parameter measuring module includes:
the first obtaining unit is used for injecting a first current signal into the power distribution network through the active inverter, and simultaneously collecting a first zero sequence voltage at a neutral point of the power distribution network through a voltage transformer to obtain a first relational expression between the first current signal and the first zero sequence voltage;
the second obtaining unit is used for injecting a second current signal into the power distribution network through the active inverter, and simultaneously collecting a second zero-sequence voltage at a neutral point of the power distribution network through the voltage transformer to obtain a second relational expression between the second current signal and the second zero-sequence voltage;
and the parameter analysis unit is used for performing fusion analysis on the first relational expression and the second relational expression to obtain the equivalent parameters of the power distribution network to the ground.
Optionally, the equivalent parameters of the distribution network to ground include a line-to-ground capacitance value and a line-to-ground leakage resistance.
Optionally, the threshold determining module is configured to perform a difference operation on a current voltage value corresponding to each phase of alternating current in the power distribution network and a voltage value at a previous time based on the current three-phase voltage, and obtain a fault phase with a difference value smaller than zero from the current voltage value.
The embodiment of the invention can synthesize a current arc extinction method and a voltage arc extinction method to effectively extinguish the arc of the ground fault of the power distribution network, and the ground resistance threshold value is taken as a switching condition in the period, so that the current arc extinction method and the voltage arc extinction method can give play to respective advantages in time: preferentially and accurately determining a fault phase in the application process of the current arc extinction method so as to meet the precondition of applying the voltage arc extinction method; the current arc extinction method can ensure the current reduction efficiency in the case of the prior low-resistance earth fault, and avoid the increased residual current risk brought by the voltage arc extinction method; the voltage arc extinction method can effectively suppress intermittent arc overvoltage caused by the current arc extinction method, can assist arc extinction work to the maximum extent, and has good practical value.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a schematic flow chart of a power distribution network ground fault arc extinction switching method disclosed by the embodiment of the invention;
FIG. 2 is a schematic diagram of a power distribution network structure based on an active inverter according to an embodiment of the present invention;
fig. 3 is a schematic composition diagram of an arc extinction switching system for a power distribution network ground fault according to an 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.
Referring to fig. 1, fig. 1 shows a schematic flow chart of a power distribution network ground fault arc extinction switching method in an embodiment of the present invention, where the method includes the following steps:
s101, injecting a current signal into the power distribution network through an active inverter, and measuring a ground equivalent parameter of the power distribution network based on the current signal;
in the embodiment of the present invention, in combination with the schematic diagram of the power distribution network structure based on the active inverter shown in fig. 2, the parameters of the power distribution network are analyzed as follows:
(1) Injecting a first current signal into a power distribution network through an active inverter
Simultaneously, a first zero sequence voltage at a neutral point of a power distribution network is acquired through a voltage transformer
Acquiring the first current signal
With said first zero sequence voltage
The first relationship between:
(2) Injecting a second current signal into the power distribution network through the active inverter
Simultaneously collecting second zero sequence voltage at the neutral point of the power distribution network through the voltage transformer
Acquiring the second current signal
And the second zero sequence voltage
The second relationship between:
(3) And performing fusion analysis on the first relational expression and the second relational expression to obtain equivalent parameters of the power distribution network to the ground, wherein the equivalent parameters of the power distribution network to the ground comprise a line capacitance value to the ground and a line leakage resistance to the ground.
Specifically, subtracting the first relational expression in step (1) from the second relational expression in step (2) can obtain:
at this time, the line-to-ground leakage resistance can be obtained as follows:
and the line-to-ground capacitance value is:
in the formula,
is the supply voltage of the a-phase line,
is the supply voltage of the B-phase line,
is the supply voltage of the C-phase line, omega is the angular frequency of the distribution network, C 0A Is A capacitance to ground, C 0B Is B relative to ground capacitance, C 0C Is C relative to ground capacitance, r A Is A relative earth leakage resistance, r B Is B relative ground leakage resistance, r C Leakage resistance is C relative to ground.
It should be noted that the active inverter adopts a three-phase cascaded H-bridge multilevel converter, and in the implementation process, the neutral point of the active inverter is grounded, and the independent three-phase branch is connected to the three-phase line of the power distribution network bus through a reactor, so as to assist in completing the work of injecting the current signal into the power distribution network by the active inverter.
S102, measuring the current zero sequence voltage and the current three-phase voltage of the power distribution network, and judging whether the power distribution network has a ground fault or not based on the current zero sequence voltage and the current three-phase voltage;
in the embodiment of the invention, the current zero sequence voltage of the power distribution network is acquired through the voltage transformer
And comparing the amplitude variation with the zero sequence voltage of the previous cycle stored in the system, and judging whether the amplitude variation generated by the two exceeds a preset threshold, wherein the judgment result comprises the following steps: if the amplitude variation is judged to exceed the preset threshold value, which indicates that the power distribution network has a ground fault, continuing to execute the step S103; and if the amplitude variation does not exceed the preset threshold value, which indicates that the power distribution network has no ground fault, returning to execute the step S101.
S103, obtaining compensation current of each phase by combining the equivalent parameters of the power distribution network to the ground, and injecting the compensation current of each phase into the power distribution network based on a current arc extinction method;
in the embodiment of the invention, the total compensation current injected into the three-phase power of the power distribution network through the active transformer is as follows:
let r be A ＝r B ＝r C ＝r 0 ，C 0A ＝C 0B ＝C 0c ＝C 0 The above-described expression for the total compensation current can be collated as:
therefore, the compensation current of each phase injected into the power distribution network by the active converter is as follows:
wherein,
injecting a compensation current for the A-phase line into the active transformer,
injecting a compensation current for the B-phase line into the active transformer,
injecting a compensation current, R, for the C-phase line into the active transformer f Is the transition resistance of the A phase and is the transition resistance of the A phase,
for the present a-phase voltage,
for the present phase-B voltage to be present,
the current C-phase voltage.
S104, determining a fault phase in the power distribution network, extracting compensation current corresponding to the fault phase from the compensation current of each phase, and determining a grounding resistance threshold value based on the compensation current;
in the embodiment of the invention, firstly, based on the current three-phase voltage, the difference operation is performed on the current voltage value corresponding to each phase of alternating current in the power distribution network and the voltage value at the previous moment, and the fault phase with the difference value smaller than zero is obtained, which is specifically represented as follows: extracting the current voltage value corresponding to the A-phase alternating current in the power distribution network from the current three-phase voltage, and subtracting the current voltage value from the A-phase voltage value of the previous period stored by the system to obtain an A-phase jump difference value delta U A Obtaining the B phase jump difference value delta U in the same way B And C phase jump difference value delta U C One or more jump difference values with a value less than zero are extracted from the three jump difference values and are designated as the accidentA jump difference of the barrier phase; next, the compensation current corresponding to the fault phase is extracted from the compensation currents of each phase in step S103, and it can be known that the fault phase is an a-phase line by combining the schematic diagram of the power distribution network structure shown in fig. 2, and since the voltage drop of a general line is not allowed to exceed 5% of the power supply voltage, the maximum allowable value of the voltage drop generated from the power distribution network bus to the fault point on the a-phase line is the maximum allowable value of the voltage drop generated from the power distribution network bus to the fault point on the a-phase line
Meanwhile, according to the maximum compensation degree V preset by a power technician, the maximum value of residual current allowed by the line can be determined by combining the compensation current of the A-phase line
Finally, the grounding resistance threshold is determined as follows:
s105, acquiring the actual grounding resistance of the fault phase, and judging whether the actual grounding resistance exceeds the grounding resistance threshold value;
in the embodiment of the invention, the voltage value of the fault point on the phase A line is directly acquired by the voltage transformer
Then the residual current value flowing through the fault point is directly collected by a current transformer
The actual grounding resistance of the A-phase circuit fault point can be acquired at the moment
Then judging the actual grounding resistance R f Whether the ground resistance threshold value R is exceeded or not fset And the judgment result comprises: if the actual grounding resistance R is judged f Exceeds the ground resistance threshold R fset If yes, continue to execute step S106; if the actual grounding resistance R is judged f The ground resistance threshold R is not exceeded fset Then, the process returns to step S103.
And S106, controlling the current phase voltage of the fault phase to be zero based on a voltage arc extinction method.
In the embodiment of the invention, current signals with specific frequency are injected to the ground by controlling the active inverter, and meanwhile, the voltage transformer is used for collecting the current zero-sequence voltage at the neutral point of the power distribution network in real time until the system monitors that the current zero-sequence voltage is equal to the negative value of the power voltage of the A-phase line, namely, the current phase voltage of the A-phase line is zero at the moment, and then the existing fault arc detector is used for detecting whether the arc of the fault point of the A-phase line is extinguished: if the arc is extinguished, controlling the active inverter to gradually reduce the injected current signal; if the electric arc is not extinguished, the A-phase fault line is directly isolated, and the electric power technical personnel are waited for manual maintenance.
Referring to fig. 3, fig. 3 is a schematic diagram illustrating a composition of a power distribution network ground fault arc extinction switching system according to an embodiment of the present invention, where the system includes the following components:
the parameter measurement module 201 is used for injecting a current signal into the power distribution network through the active inverter and measuring a ground equivalent parameter of the power distribution network based on the current signal;
specifically, the parameter measurement module 201 includes a first obtaining unit, a second obtaining unit and a parameter analysis unit; the first obtaining unit is used for injecting a first current signal into the power distribution network through the active inverter, and simultaneously collecting a first zero sequence voltage at a neutral point of the power distribution network through a voltage transformer to obtain a first relation between the first current signal and the first zero sequence voltage; the second obtaining unit is used for injecting a second current signal into the power distribution network through the active inverter, and simultaneously collecting a second zero-sequence voltage at a neutral point of the power distribution network through the voltage transformer to obtain a second relational expression between the second current signal and the second zero-sequence voltage; the parameter analysis unit is used for performing fusion analysis on the first relational expression and the second relational expression to obtain equivalent parameters of the power distribution network to the ground, wherein the equivalent parameters of the power distribution network to the ground comprise a line to the ground capacitance value and a line to the ground leakage resistance.
The fault judgment module 202 is configured to measure a current zero-sequence voltage and a current three-phase voltage of the power distribution network, and judge whether a ground fault occurs in the power distribution network based on the current zero-sequence voltage and the current three-phase voltage;
the current control module 203 is used for acquiring each phase of compensation current by combining with the ground equivalent parameters of the power distribution network after judging that the power distribution network has a ground fault, and injecting each phase of compensation current into the power distribution network based on a current arc extinction method;
a threshold determining module 204, configured to determine a fault phase in the power distribution network, extract a compensation current corresponding to the fault phase from the compensation currents of each phase, and determine a ground resistance threshold based on the compensation current;
specifically, the threshold determining module 204 is configured to perform a difference operation on a current voltage value corresponding to each phase of alternating current in the power distribution network and a voltage value at a previous time based on the current three-phase voltage, and obtain a fault phase with a difference value smaller than zero from the current voltage value.
The resistance judgment module 205 is configured to obtain an actual ground resistance of the fault phase, and judge whether the actual ground resistance exceeds the ground resistance threshold;
and the voltage control module 206 is configured to control the current phase voltage of the fault phase to be zero based on a voltage arc extinction method after the actual ground resistance is judged to exceed the ground resistance threshold.
For specific embodiments of each module in the system, please refer to the method flowchart and specific implementation contents shown in fig. 1, which are not described herein again.
The embodiment of the invention can synthesize a current arc extinction method and a voltage arc extinction method to effectively extinguish the arc of the ground fault of the power distribution network, and the ground resistance threshold value is taken as a switching condition in the period, so that the current arc extinction method and the voltage arc extinction method can give play to respective advantages in time: preferentially and accurately determining a fault phase in the application process of the current arc extinction method so as to meet the precondition of applying the voltage arc extinction method; the current arc extinction method can ensure the current reduction efficiency in the case of the prior low-resistance earth fault, and avoid the increased residual current risk brought by the voltage arc extinction method; the voltage arc extinction method can effectively suppress intermittent arc overvoltage caused by the current arc extinction method, can assist arc extinction work to the maximum extent, and has good practical value.
Those skilled in the art will appreciate that all or part of the steps in the methods of the above embodiments may be implemented by hardware related to instructions of a program, and the program may be stored in a computer-readable storage medium, and the storage medium may include: read Only Memory (ROM), random Access Memory (RAM), magnetic or optical disks, and the like.
The method and the system for arc extinction and switching of the power distribution network ground fault provided by the embodiment of the invention are described in detail, a specific example is adopted in the method to explain the principle and the implementation mode of the invention, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.
Claims (4)
1. An arc extinction switching method for a power distribution network ground fault is characterized by comprising the following steps:
injecting a current signal into the power distribution network through the active inverter, and measuring a ground equivalent parameter of the power distribution network based on the current signal;
measuring the current zero sequence voltage and the current three-phase voltage of the power distribution network, and judging whether the power distribution network has a ground fault or not based on the current zero sequence voltage and the current three-phase voltage;
after the power distribution network is judged to have the ground fault, each phase of compensation current is obtained by combining the ground equivalent parameters of the power distribution network, and each phase of compensation current is injected into the power distribution network based on the current arc extinction;
determining a fault phase in a power distribution network, extracting compensation current corresponding to the fault phase from the compensation current of each phase, and determining a grounding resistance threshold value based on the compensation current;
acquiring the actual grounding resistance of the fault phase, and judging whether the actual grounding resistance exceeds the grounding resistance threshold value;
after the actual grounding resistance is judged to exceed the grounding resistance threshold, the current phase voltage of the fault phase is controlled to be zero based on a voltage arc extinction method;
the current signal is injected into the power distribution network through the active inverter, and the measurement of the equivalent parameters of the power distribution network to the ground based on the current signal comprises the following steps:
injecting a first current signal into the power distribution network through an active inverter, and acquiring a first zero-sequence voltage at a neutral point of the power distribution network through a voltage transformer to obtain a first relational expression between the first current signal and the first zero-sequence voltage;
injecting a second current signal into the power distribution network through the active inverter, and acquiring a second zero-sequence voltage at a neutral point of the power distribution network through the voltage transformer to obtain a second relational expression between the second current signal and the second zero-sequence voltage;
performing fusion analysis on the first relational expression and the second relational expression to obtain equivalent parameters of the power distribution network to the ground;
the equivalent parameters of the power distribution network to the ground comprise a line-to-ground capacitance value and a line-to-ground leakage resistance;
the determining a fault phase in the power distribution network comprises:
and based on the current three-phase voltage, performing difference operation on a current voltage value corresponding to each phase of alternating current in the power distribution network and a voltage value at the previous moment, and acquiring a fault phase with a difference value smaller than zero.
2. The arc extinction switching method for the power distribution network ground fault according to claim 1, wherein after judging whether the power distribution network has the ground fault or not based on the current zero sequence voltage and the current three-phase voltage, the method further comprises:
and if the power distribution network is judged not to have the ground fault, returning to inject a current signal into the power distribution network through the active inverter.
3. The power distribution network ground fault arc extinction switching method according to claim 1, after judging whether the actual ground resistance exceeds the ground resistance threshold value, further comprising:
and if the actual grounding resistance does not exceed the grounding resistance threshold, returning to inject the compensation current of each phase into the power distribution network based on the current arc extinction.
4. A power distribution network ground fault arc extinction switching system, characterized in that the system comprises:
the parameter measurement module is used for injecting a current signal into the power distribution network through the active inverter and measuring the equivalent parameters of the power distribution network to the ground based on the current signal;
the fault judgment module is used for measuring the current zero sequence voltage and the current three-phase voltage of the power distribution network and judging whether the power distribution network has a ground fault or not based on the current zero sequence voltage and the current three-phase voltage;
the current control module is used for acquiring each phase of compensation current by combining with the ground equivalent parameters of the power distribution network after judging that the power distribution network has a ground fault, and injecting each phase of compensation current into the power distribution network based on a current arc extinction method;
the threshold value determining module is used for determining a fault phase in the power distribution network, extracting compensation current corresponding to the fault phase from the compensation current of each phase, and determining a ground resistance threshold value based on the compensation current;
the resistance judgment module is used for acquiring the actual grounding resistance of the fault phase and judging whether the actual grounding resistance exceeds the grounding resistance threshold value;
the voltage control module is used for controlling the current phase voltage of the fault phase to be zero based on a voltage arc extinction method after the actual ground resistance is judged to exceed the ground resistance threshold;
the parameter measurement module includes:
the first obtaining unit is used for injecting a first current signal into the power distribution network through the active inverter, and simultaneously collecting a first zero sequence voltage at a neutral point of the power distribution network through a voltage transformer to obtain a first relational expression between the first current signal and the first zero sequence voltage;
the second obtaining unit is used for injecting a second current signal into the power distribution network through the active inverter, and acquiring a second zero-sequence voltage at a neutral point of the power distribution network through the voltage transformer to obtain a second relation between the second current signal and the second zero-sequence voltage;
the parameter analysis unit is used for performing fusion analysis on the first relational expression and the second relational expression to obtain equivalent parameters of the power distribution network to the ground;
the power distribution network ground equivalent parameters comprise a line-to-ground capacitance value and a line-to-ground leakage resistance;
and the threshold value determining module is used for performing difference operation on a current voltage value corresponding to each phase of alternating current in the distribution network and a voltage value at the previous moment based on the current three-phase voltage, and acquiring a fault phase with a difference value smaller than zero from the current voltage value.
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| CN113178854B (en) * | 2021-04-27 | 2023-12-29 | 福州大学 | Flexible distributed arc extinction method for power distribution network ground fault based on master-slave control |
| CN113270860B (en) * | 2021-06-29 | 2022-06-21 | 南方电网科学研究院有限责任公司 | Single-phase earth fault arc extinction device of power distribution network |
| CN113820620A (en) * | 2021-08-17 | 2021-12-21 | 捍防（深圳）实业有限公司 | Fault analysis method and fault analysis device for power supply system |
| CN114285009B (en) * | 2021-12-14 | 2023-11-24 | 国网江苏省电力有限公司常州供电分公司 | Active voltage arc extinction method based on neutral point injection current |
| CN117277246B (en) * | 2023-11-15 | 2024-02-06 | 昆明理工大学 | Active and passive combined power distribution network ground fault self-adaptive arc extinction method |
| CN117277248B (en) * | 2023-11-17 | 2024-02-20 | 昆明理工大学 | Active arc extinction voltage-current conversion method, system and medium for power distribution network |
| CN117277249B (en) * | 2023-11-20 | 2024-01-30 | 昆明理工大学 | Single-phase earth fault voltage and current matching arc extinction method and system for power distribution network |
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| CN106655144A (en) * | 2017-02-13 | 2017-05-10 | 云南电网有限责任公司电力科学研究院 | Dual-closed-loop control-based active voltage arc extinction method and apparatus for power distribution network in fault |
| CN110880750A (en) * | 2019-12-24 | 2020-03-13 | 长沙理工大学 | Power distribution network ground fault arc extinction method based on three-phase half-bridge inverter |
| WO2020087811A1 (en) * | 2018-11-01 | 2020-05-07 | 杭州求创电力科技有限公司 | Method for suppressing fault phase residual voltage of resonant grounding system based on precise tuning control on active adjustable complex impedance |
Family Cites Families (7)
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|---|---|---|---|---|
| EP1693679B1 (en) * | 2005-02-21 | 2014-06-11 | Adaptive Regelsysteme GmbH | Method for the determination of a parameter of an electric power supply network |
| CN103545796A (en) * | 2013-09-16 | 2014-01-29 | 国家电网公司 | Single-phase grounding fault handling device and method for power distribution network with non-effectively grounded neutral points |
| CN104218563B (en) * | 2014-09-26 | 2018-01-12 | 福州大学 | The distribution network failure arc extinguishing method that a kind of neutral point is grounded through Multilevel Inverters |
| CN105610147B (en) * | 2016-03-24 | 2018-03-16 | 福州大学 | A kind of distribution network ground fault arc extinction method based on three-phase cascaded H-bridges current transformer |
| US10333290B2 (en) * | 2016-12-08 | 2019-06-25 | Schneider Electric USA, Inc. | Multi-winding ground fault sensor |
| CN108347046B (en) * | 2017-01-24 | 2019-08-06 | 中国石油化工股份有限公司 | A kind of small current grounding fault New Method of Active Electronic Compensation and system |
| EP3506445B1 (en) * | 2017-12-27 | 2021-05-12 | ABB Schweiz AG | System for identification of a feeder with high-ohmic earth fault in a distribution network |
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| CN106655144A (en) * | 2017-02-13 | 2017-05-10 | 云南电网有限责任公司电力科学研究院 | Dual-closed-loop control-based active voltage arc extinction method and apparatus for power distribution network in fault |
| WO2020087811A1 (en) * | 2018-11-01 | 2020-05-07 | 杭州求创电力科技有限公司 | Method for suppressing fault phase residual voltage of resonant grounding system based on precise tuning control on active adjustable complex impedance |
| CN110880750A (en) * | 2019-12-24 | 2020-03-13 | 长沙理工大学 | Power distribution network ground fault arc extinction method based on three-phase half-bridge inverter |
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