CN111146773A - Single-phase earth fault self-healing method for small current grounding system - Google Patents

Single-phase earth fault self-healing method for small current grounding system Download PDF

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CN111146773A
CN111146773A CN201911333181.9A CN201911333181A CN111146773A CN 111146773 A CN111146773 A CN 111146773A CN 201911333181 A CN201911333181 A CN 201911333181A CN 111146773 A CN111146773 A CN 111146773A
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phase
fault
traveling wave
self
healing
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Inventor
朱皓
施慎行
赵一名
董新洲
文忠进
张锐锋
张裕
汤铁军
华龙
唐仲伟
陈正慧
王磊
肖小兵
赵圆圆
何洪流
武昌平
张梦纯
陈航
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Guizhou Power Grid Co Ltd
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Guizhou Power Grid Co Ltd
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    • 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
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/02—Details
    • H02H3/06—Details with automatic reconnection
    • H02H3/066—Reconnection being a consequence of eliminating the fault which caused disconnection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/30—Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
    • Y04S20/20—End-user application control systems

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  • Emergency Management (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

The invention provides a self-healing method for a single-phase earth fault of a low-current grounding system, which comprises the following steps: collecting electric signals of the power transmission line in real time; when the electrical signal is abnormal, identifying the fault type according to the electrical quantity characteristics; when the single-phase earth fault is identified, the implementation strategy of the self-healing of the fault is specifically as follows: three-phase tripping of the circuit breaker; carrying out three-phase automatic reclosing, wherein if the fault is instantaneous, the fault disappears and the reclosing is successful; if the fault is a permanent fault, reclosing fails, the breaker immediately trips again, the opposite side breaker trips in an accelerated manner, a standby power supply is automatically switched in, and fault self-healing is achieved. The self-healing method and the self-healing system provided by the invention are beneficial to accelerating the isolation and power restoration of a fault section, reducing the power failure time and the power failure range, reducing the economic and social losses caused by power failure and providing the power supply reliability.

Description

Single-phase earth fault self-healing method for small current grounding system
Technical Field
The invention relates to the technical field of power systems, in particular to a self-healing method for a single-phase earth fault of a low-current grounding system.
Background
The power distribution network is an important component of a power system and is also an important link for power supply of users. The power supply reliability of the system is greatly influenced by the neutral point grounding mode of the power distribution network. At present, a neutral point of a power distribution network usually adopts a low-current grounding mode, and a system with no obvious overcurrent is available after a single-phase grounding fault occurs. Structurally, the distribution network usually adopts an open-loop structure and a closed-loop operation mode. Each feeder is provided with segment protection, and the segment protection is single circuit breaker protection. Distribution automation is an important guarantee for realizing safe, reliable and continuous power supply for power consumers. In the related prior art, an effective method for quickly and accurately judging and self-healing the single-phase earth fault of a low-current grounding system is lacked, the manual routing inspection adopted at present is complicated in fault judging and processing mode, timely and accurate judgment of the single-phase earth fault is difficult to realize, the fault processing efficiency is low, and the realization of distribution automation is not facilitated.
Disclosure of Invention
The invention aims to solve the technical problems and provides a relatively accurate and efficient self-healing method for a single-phase earth fault of a low-current grounding system, which is beneficial to improving distribution automation management.
The invention discloses a single-phase earth fault self-healing method of a small current grounding system, which comprises the following steps:
s1, collecting electric signals of the electric transmission line in real time;
s2, when the electrical signal is abnormal, identifying the fault type according to the electrical quantity characteristics;
s3, performing fault self-healing according to the fault type, wherein the implementation strategy of the fault self-healing specifically comprises the following steps:
if the fault is a single-phase earth fault, the three-phase tripping of the breaker is carried out;
carrying out three-phase automatic reclosing, wherein if the fault is instantaneous, the fault disappears and the reclosing is successful; if the fault is a permanent fault, reclosing fails, the breaker immediately trips again, the opposite side breaker trips in an accelerated manner, a standby power supply is automatically switched in, and fault self-healing is achieved.
Preferably, the electrical signals include three-phase power frequency voltage signals, three-phase voltage traveling wave signals and three-phase current traveling wave signals.
Preferably, the sampling frequency of the power frequency three-phase voltage signal is 1kHz, and the sampling frequencies of the three-phase voltage traveling wave signal and the three-phase current traveling wave signal are both 1 MHz.
Preferably, the identifying the fault type according to the electrical quantity characteristic specifically includes:
firstly, carrying out phase sequence transformation processing on the collected power frequency electric quantity, carrying out three-phase decoupling on the power frequency electric quantity, and respectively converting ABC three-phase quantity into positive sequence, negative sequence and zero sequence components;
then, performing Discrete Fourier Transform (DFT) on the power frequency electric quantity, and calculating the fundamental wave amplitude of the required power frequency quantity to obtain power frequency three-phase voltage;
finally, judging the single-phase earth fault of the low-current earth system according to the following criteria: a phase voltage is smaller than a threshold value epsilon and is close to 0; the other two phases of voltage exceed the threshold value UsetRises to the original
Figure BDA0002330220870000021
Doubling; zero sequence voltage super-threshold value U0.set(ii) a The power frequency starting criterion is as follows:
Figure BDA0002330220870000022
preferably, if the fault is a single-phase ground fault, the circuit breaker triphase tripping specifically includes:
firstly, carrying out phase-mode conversion processing on the collected traveling wave electric quantity, carrying out three-phase decoupling on the traveling wave electric quantity, wherein the phase-mode conversion comprises Kernenbel conversion and Clark conversion, and judging whether the circuit breaker is positioned on a power supply side or a load side of a fault point by utilizing a zero-mode voltage traveling wave and a zero-mode current wave.
Preferably, the zero-mode voltage traveling wave and the zero-mode voltage prevailing wave are subjected to binary wavelet transform, the derivative of a cubic B-spline function is selected as the basic wavelet function of the binary wavelet transform, the third-scale wavelet transform modulus maximum is adopted, and the initial zero-mode voltage traveling wave are usedWavelet transformation modulus maximum M corresponding to zero-modulus current traveling waveU、MIRepresents the polarity of the traveling wave:
Figure BDA0002330220870000023
the criterion of the traveling wave starting is as follows: the polarity of the head wave mode maximum value of the voltage traveling wave and the current traveling wave is opposite, starting is judged, and the circuit breaker on the power supply side is guaranteed to trip firstly;
the time setting principle is as follows: the action time of the circuit breaker is set according to a trapezoidal principle, and the setting time from the tail end of the circuit to the head end of the circuit is increased in sequence.
Preferably, the opposite side circuit breaker is accelerated to trip, and the standby power supply is automatically switched on, and the method specifically comprises the following steps:
according to the electrical quantity characteristic of the healthy full phase after the circuit breaker is tripped off again, an acceleration criterion is constructed, the opposite-side circuit breaker is accelerated to trip, and the acceleration criterion of the opposite-side circuit breaker is as follows:
in the time window, the three-phase low voltage appears on the line twice continuously, and the three-phase voltage is close to 0 at the same time;
after the opposite side circuit breaker is accelerated to be tripped, a standby power supply is switched in through an automatic switching device, and power supply recovery of an original load side circuit is achieved.
Compared with the prior art, the invention has the remarkable improvements at least in that:
the small-current grounding system single-phase grounding fault self-healing method can reduce unnecessary power failure caused by transient faults, shorten power failure time, reduce power failure range, reduce economic loss caused by power failure, effectively improve power supply reliability, avoid single-phase grounding operation of a distribution line, effectively protect personal safety, and has high practical value and economic value.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
Fig. 1 is a logic flow diagram of a single-phase ground fault self-healing method of a low-current grounding system according to an embodiment of the present invention;
figure 2 is a schematic diagram of a power distribution network according to one embodiment of the present invention.
Detailed Description
In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced otherwise than as specifically described herein, and thus the scope of the present invention is not limited by the specific embodiments disclosed below.
The invention discloses a single-phase earth fault self-healing method of a small current grounding system, which comprises the following steps:
s1, collecting electric signals of the electric transmission line in real time;
s2, when the electrical signal is abnormal, identifying the fault type according to the electrical quantity characteristics;
s3, performing fault self-healing according to the fault type, wherein the implementation strategy of the fault self-healing specifically comprises the following steps:
if the fault is a single-phase earth fault, the three-phase tripping of the breaker is carried out;
carrying out three-phase automatic reclosing, wherein if the fault is instantaneous, the fault disappears and the reclosing is successful; if the fault is a permanent fault, reclosing fails, the breaker immediately trips again, the opposite side breaker trips in an accelerated manner, a standby power supply is automatically switched in, and fault self-healing is achieved. Fig. 1 is a logic flow diagram illustrating a self-healing method for a single-phase ground fault of a low-current grounding system according to an embodiment.
As a preferred embodiment scheme, the method comprises the steps of collecting three-phase power frequency voltage signals, three-phase voltage traveling wave signals and three-phase current traveling wave signals of the power frequency three-phase voltage signals in real time, further, enabling the sampling frequency of the power frequency three-phase voltage signals to be 1kHz, enabling the sampling frequency of the three-phase voltage traveling wave signals and the sampling frequency of the three-phase current traveling wave signals to be 1MHz, and enabling a high-frequency measuring device meeting the requirements of traveling wave sampling rate to be adopted for collection and measurement. And according to the collected traveling wave signals, the method can be used for judging whether traveling wave disturbance occurs in the monitored power transmission line network.
As a preferred embodiment, the identifying the fault type according to the electrical quantity characteristic specifically includes:
firstly, the phase sequence transformation processing is carried out on the collected power frequency electric quantity, the three-phase decoupling is carried out on the power frequency electric quantity, and the ABC three-phase quantity is converted into positive sequence, negative sequence and zero sequence components. Wherein the zero sequence voltage can be used to judge the ground fault.
And then carrying out discrete Fourier transform on the power frequency electric quantity. For the power frequency criterion, power frequency zero sequence voltage and power frequency three-phase voltage need to be calculated, so that Discrete Fourier Transform (DFT) is needed to calculate the fundamental amplitude of the required power frequency quantity.
The criterion of the single-phase earth fault of the small-current earthing system is as follows: one phase voltage UALess than a set threshold epsilon, close to 0; another two-phase voltage UBAnd UCOver-set threshold UsetRises to the original
Figure BDA0002330220870000041
Doubling; zero sequence voltage U0Super threshold U0.set. The corresponding power frequency starting criterion is as follows:
Figure BDA0002330220870000051
in the technical scheme, the fault type is identified by using the power frequency voltage characteristics after the single-phase earth fault of the low-current earthing system, so that the problem that the single-phase earth fault of the distribution line caused by the ungrounded neutral point is difficult to identify can be effectively solved.
As a preferred embodiment, if the fault is a single-phase ground fault, the three-phase trip of the circuit breaker specifically includes:
firstly, the collected traveling wave electric quantity is processed by phase-mode conversion, and for the three-phase decoupling of the traveling wave quantity, the phase-mode conversion is usually adopted. The phase-mode transformation generally used includes kelnbel transformation, clarke transformation, and the like, and the kelnbel transformation can be preferably used in the present embodiment.
Further, the zero-mode voltage traveling wave and the zero-mode current wave are used for judging whether the circuit breaker is positioned on the power supply side or the load side of the fault point. Specifically, the binary wavelet transform is performed on the zero-mode voltage traveling wave and the zero-mode voltage prevailing wave, a plurality of basis functions corresponding to the binary wavelet transform exist, the derivative function of the cubic B-spline function needs the least support in all the polynomial bar functions, and good approximation similar to a Gaussian function can be obtained. Therefore, in this embodiment, the derivative of the cubic B-spline function is selected as the basic wavelet function of the dyadic wavelet transform, and the third scale wavelet transform modulus maximum is adopted, and the wavelet transform modulus maximum M corresponding to the initial zero-mode voltage traveling wave and the initial zero-mode current traveling wave is usedU、MIPositive and negative to characterize the polarity of the traveling wave.
Figure BDA0002330220870000052
The criterion of the traveling wave starting is as follows: the voltage traveling wave and the current traveling wave have opposite polarity of the head mode maximum value, namely MU×MI<And 0, judging to be started regularly, and ensuring that the circuit breaker on the power supply side trips first.
The time setting principle of the breaker action is as follows: the action time of the circuit breaker is set according to a trapezoidal principle, and the setting time from the tail end of the circuit to the head end of the circuit is sequentially increased, as shown in an abstract attached drawing.
In the technical scheme, the polarity characteristics of the zero-mode voltage traveling wave and the zero-mode current traveling wave are utilized to realize effective identification of a fault section, and when a single-phase earth fault is ensured, a breaker at the upstream of a fault point, namely a power supply side, acts first to prepare for removing transient faults by reclosing.
As a preferred embodiment scheme, the accelerated tripping of the side circuit breaker and the automatic switching of the standby power supply specifically include:
and constructing an acceleration criterion according to the electrical quantity characteristics of the sound phase after the circuit breaker is tripped again, and accelerating tripping of the opposite circuit breaker. The protection acceleration criterion of the side breaker is as follows:
in the time window, the three-phase low voltage appears on the line twice continuously, and the three-phase voltage is close to 0 at the same time, and the characteristics are as follows:
Figure BDA0002330220870000061
and finally, switching in a standby power supply through an automatic switching device to realize power supply recovery of the original load side circuit.
In the technical scheme, the rapid isolation of a fault section is realized by using channel-free protection, and the tripping of the load side circuit breaker is accelerated according to secondary disturbance information after the power supply side circuit breaker trips. The channel-less protection can quickly and selectively isolate asymmetric faults occurring on the distribution line from a power supply side and a load side on the premise of not depending on communication, and the load in a non-fault section is restored to be supplied with power through a standby power automatic switching device (BZT).
It is understood that faults occurring in distribution overhead lines or hybrid overhead and cable lines are dominated by transient faults. After the circuit breaker acts for the first time to remove the fault, the insulation strength of the fault point can be recovered again, and if the disconnected circuit breaker is closed again at the moment, normal power supply can be recovered, so that the power supply reliability can be effectively improved, unnecessary power failure is reduced, the power failure time is shortened, the power failure range is reduced, and the economic loss caused by power failure is avoided. Meanwhile, if the first reclosing failure occurs, the fault can be determined to be a permanent fault, the second tripping operation is immediately carried out, meanwhile, the opposite terminal is protected to perform acceleration action, single-phase grounding operation of a distribution line is avoided, personal safety is effectively protected, and electric shock accidents are avoided.
According to the single-phase earth fault self-healing method for the small-current grounding system, the three-phase primary reclosing is carried out through the breaker on the power supply side, the instantaneous fault can be successfully reclosed, the permanent fault immediately trips for the second time, and meanwhile the load side trips in an accelerated mode. And the load side breaker has a reclosing function after tripping, the downstream load of the load side breaker acts by the automatic throw-in device of the standby power supply, and the ring network switch recovers power supply after closing. The technical scheme provided by the invention has very high practical value and economic value. Fig. 2 is a schematic diagram of a power distribution network for implementing the fault self-healing method according to an embodiment.
In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (7)

1. A self-healing method for single-phase earth fault of a low-current grounding system is characterized by comprising the following steps:
s1, collecting electric signals of the electric transmission line in real time;
s2, when the electrical signal is abnormal, identifying the fault type according to the electrical quantity characteristics;
s3, performing fault self-healing according to the fault type, wherein the implementation strategy of the fault self-healing specifically comprises the following steps:
if the fault is a single-phase earth fault, the three phases of the circuit breaker are tripped out, then three-phase automatic reclosing is carried out, and if the fault is an instantaneous fault, the fault disappears and the reclosing is successful; if the fault is a permanent fault, reclosing fails, the breaker immediately trips again, the opposite side breaker trips in an accelerated manner, a standby power supply is automatically switched in, and fault self-healing is achieved.
2. A self-healing method for a single-phase earth fault of a low-current grounding system according to claim 1, wherein the electrical signals include three-phase power-frequency voltage signals, three-phase voltage traveling wave signals and three-phase current traveling wave signals.
3. A self-healing method for a single-phase earth fault of a low-current grounding system according to claim 2, wherein the sampling frequency for the power frequency three-phase voltage signal is 1kHz, and the sampling frequencies for the three-phase voltage traveling wave signal and the three-phase current traveling wave signal are both 1 MHz.
4. A self-healing method for a single-phase earth fault of a low-current grounding system according to claim 1, wherein the fault type identification according to the electrical quantity characteristics specifically includes:
firstly, carrying out phase sequence transformation processing on the collected power frequency electric quantity, carrying out three-phase decoupling on the power frequency electric quantity, and respectively converting ABC three-phase quantity into positive sequence, negative sequence and zero sequence components;
then, performing Discrete Fourier Transform (DFT) on the power frequency electric quantity, and calculating the fundamental wave amplitude of the required power frequency quantity to obtain power frequency three-phase voltage;
finally, judging the single-phase earth fault of the low-current earth system according to the following criteria: one phase voltage UALess than a set threshold epsilon, close to 0; another two-phase voltage UBAnd UCSuper threshold UsetRises to the original
Figure FDA0002330220860000011
Doubling; zero sequence voltage U0Super threshold U0.set(ii) a The corresponding power frequency starting criterion is as follows:
Figure FDA0002330220860000012
5. a self-healing method for a single-phase earth fault of a low-current grounding system according to claim 1, wherein if the single-phase earth fault occurs, a three-phase trip of a circuit breaker specifically includes:
firstly, carrying out phase-mode conversion processing on the collected traveling wave electric quantity, carrying out three-phase decoupling on the traveling wave electric quantity, wherein the phase-mode conversion comprises Kernenbel conversion and Clark conversion, and judging whether the circuit breaker is positioned on a power supply side or a load side of a fault point by utilizing a zero-mode voltage traveling wave and a zero-mode current wave.
6. The single-phase earth fault self-healing method of the small current grounding system according to claim 5, wherein the zero-mode voltage traveling wave and the zero-mode current traveling wave are subjected to a dyadic wavelet transform, the derivative of a cubic B-spline function is selected as the basic wavelet function of the dyadic wavelet transform, a third-scale wavelet transform modulus maximum value is adopted, and a wavelet transform modulus maximum value M corresponding to the initial zero-mode voltage traveling wave and the initial zero-mode current traveling wave is adoptedU、MIRepresents the polarity of the traveling wave:
Figure FDA0002330220860000021
the criterion of the traveling wave starting is as follows: the polarity of the head wave mode maximum value of the voltage traveling wave and the current traveling wave is opposite, the judgment is started, and a breaker on the power supply side trips firstly;
the time setting principle is as follows: the action time of the circuit breaker is set according to a trapezoidal principle, and the setting time from the tail end of the circuit to the head end of the circuit is increased in sequence.
7. The small-current grounding system single-phase grounding fault self-healing method according to claim 4, wherein the accelerated tripping of the side circuit breaker and the automatic switching of the standby power supply specifically comprise:
according to the electrical quantity characteristic of the healthy full phase after the circuit breaker is tripped off again, an acceleration criterion is constructed, the opposite-side circuit breaker is accelerated to trip, and the acceleration criterion of the opposite-side circuit breaker is as follows: in the time window, the three-phase low voltage appears on the line twice continuously, and the three-phase voltage is close to 0 at the same time;
after the opposite side circuit breaker is accelerated to be tripped, a standby power supply is switched in through an automatic switching device, and power supply recovery of an original load side circuit is achieved.
CN201911333181.9A 2019-12-23 2019-12-23 Single-phase earth fault self-healing method for small current grounding system Pending CN111146773A (en)

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CN112285601A (en) * 2020-10-16 2021-01-29 太原理工大学 Multi-terminal low-current grounding flexible direct current system single-pole grounding fault line selection method
CN112436478A (en) * 2020-11-12 2021-03-02 贵州电网有限责任公司 Automatic reclosing method based on cooperation of SPSR distribution line and channel-free protection
CN112578315A (en) * 2020-11-26 2021-03-30 贵州电网有限责任公司 Control loop disconnection fault judgment method based on matrix diagram

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CN112436478A (en) * 2020-11-12 2021-03-02 贵州电网有限责任公司 Automatic reclosing method based on cooperation of SPSR distribution line and channel-free protection
CN112578315A (en) * 2020-11-26 2021-03-30 贵州电网有限责任公司 Control loop disconnection fault judgment method based on matrix diagram
CN112578315B (en) * 2020-11-26 2022-08-26 贵州电网有限责任公司 Control loop disconnection fault judgment method based on matrix diagram

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Application publication date: 20200512