CN114062850B - Double-threshold power grid early fault detection method - Google Patents

Double-threshold power grid early fault detection method Download PDF

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CN114062850B
CN114062850B CN202111359977.9A CN202111359977A CN114062850B CN 114062850 B CN114062850 B CN 114062850B CN 202111359977 A CN202111359977 A CN 202111359977A CN 114062850 B CN114062850 B CN 114062850B
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吴定会
张娟
唐丹丹
张文峰
沈艳霞
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Jiangnan University
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    • G01R31/08Locating faults in cables, transmission lines, or networks
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    • G01R31/086Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
    • GPHYSICS
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    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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Abstract

The invention discloses a double-threshold power grid early fault detection method, which comprises the following steps: the method comprises the following steps: collecting power grid state data in real time, and arranging the data according to a time sequence to form a state matrix; step two: at each sampling time t, obtaining a non-metric matrix through data processing according to the constructed state matrix; step three: according to the constructed non-metric matrix, obtaining an early fault detection index D through feature decomposition t (ii) a Step four: based on Tracy-Widom distribution, fault detection dual-threshold gamma is calculated according to given false alarm probability and dimensionality of window matrix 1 And gamma 2 (ii) a Step five: according to the constructed early fault detection index D t With a threshold value gamma 1 And gamma 2 The magnitude relation of (2) detects the early failure of the power grid. The fault detection method can find the fault earlier, and particularly, the detection of the early fault is more accurate and advanced.

Description

Double-threshold power grid early fault detection method
Technical Field
The invention belongs to the technical field of power grid fault detection, and particularly relates to a double-threshold power grid early fault detection method.
Background
In the operation process of the power grid, the power grid is easily influenced by the external environment and the internal structure to break down. At the early stage of the fault, the influence on the power system is small, the fault characteristics are not obvious, and the fault is detected and eliminated, so that the fault can be prevented from being further expanded, the safety threat of the fault to a power grid is reduced, and the method has important significance for social and economic development.
The existing power grid fault detection method mainly comprises a model method and a data method. Wherein, the model method faces the problems of complex modeling process, difficult solving and the like; the data method is more suitable for analyzing and processing massive and various characteristic power grid state data, so that efficient fault detection is realized.
The conventional data method is mainly based on a random matrix theory, comprises an analysis method based on characteristic values of a unitary matrix and an analysis method based on characteristic values of a sample covariance matrix, and realizes fault detection by analyzing a state matrix constructed by power grid state data. When the power grid normally operates without faults, a state matrix constructed by the power grid state data is a random matrix, and the characteristic value of the matrix meets the random matrix theory; on the contrary, when the system breaks down, the running state of the power grid is changed, the randomness of the system is damaged, and the characteristic value of the state matrix no longer meets the random matrix theory.
The existing grid fault detection method based on the random matrix theory can be divided into three categories, and specifically, an average spectrum radius method is constructed based on the characteristic value characteristic of a unitary matrix; based on the sample covariance matrix, a spectral deviation method and a maximum eigenvalue method are constructed. The average spectrum radius method does not consider the random variation condition of noise, the fault detection sensitivity is reduced under the environment with low signal-to-noise ratio, and the fault detection speed is relatively slow due to the analysis operation based on the unitary matrix; the analysis method based on the sample covariance matrix shortens the calculation time and improves the operation analysis efficiency, but the fault detection precision needs to be further improved; in addition, the above methods are all single threshold methods, and the sensitivity of early fault detection, in which the fault characteristics are not obvious, is insufficient.
Disclosure of Invention
In order to overcome the defects of the existing power grid early fault detection method, the invention provides a dual-threshold power grid early fault detection method based on the principle that the maximum and minimum characteristic values of a sample covariance matrix in a random matrix theory meet Tracy-Widom distribution, and the analysis efficiency and the fault detection precision of the existing method are effectively improved.
In order to achieve the purpose, the method for detecting the early fault of the power grid comprises the following steps:
the method comprises the following steps: collecting power grid state data in real time, and arranging the data according to a time sequence to form a state matrix X;
step two: at each sampling time t, according toThe constructed state matrix X is processed by data to obtain a non-metric matrix
Figure GDA0003733932590000011
Step three: according to the constructed non-metric matrix
Figure GDA0003733932590000012
Obtaining early fault detection index D through feature decomposition t
Step four: based on Tracy-Widom distribution, fault detection dual-threshold gamma is calculated according to given false alarm probability and dimensionality of window matrix 1 And gamma 2
Step five: according to the constructed early fault detection index D t With a threshold value gamma 1 And gamma 2 The magnitude relation of (2) detects the early fault of the power grid.
Specifically, the power grid state data in step 1 is acquired by a wide area measurement unit.
The power grid state data in the step 1 comprise one or more of node voltage, branch current, load active power and reactive power, and each state data is analyzed independently.
Specifically, the data processing process in the second step is as follows: construction of a window matrix X using a sliding time window model t (ii) a According to the constructed window matrix X t Normalizing the state data by the row transformation of the formula (1) to obtain a non-metric matrix
Figure GDA0003733932590000013
Figure GDA0003733932590000014
Wherein the element in (1) is represented by formula;
Figure GDA0003733932590000015
wherein i is 1,2, …, N, N is the constructed window matrix X t The number of lines of (1) represents the collected formThe number of state variables; j is 1,2, …, T W ,T W Is a window matrix X t The number of columns of (a), i.e. the width of the sliding time window; x is a radical of a fluorine atom i,j Representing a window matrix X t The elements of (a) and (b),
Figure GDA0003733932590000021
is a window matrix X t The row vector of (2);
Figure GDA0003733932590000022
representing normalized matrix
Figure GDA0003733932590000023
The elements of (a) and (b),
Figure GDA0003733932590000024
is a matrix
Figure GDA0003733932590000025
The row vector of (2); mu (x) i ) Is a matrix X t Mean value of the row vectors of (a), σ (x) i ) Is a window matrix X t The standard deviation of the row vector of (a);
Figure GDA0003733932590000026
for normalized matrix
Figure GDA0003733932590000027
Of the average value of the row vectors of (a),
Figure GDA0003733932590000028
is a matrix
Figure GDA0003733932590000029
The standard deviation of the row vector of (c).
Specifically, the feature decomposition process in the third step includes: according to the constructed non-metric matrix
Figure GDA00037339325900000210
Calculating a sample covariance matrix S according to equation (2) t
Figure GDA00037339325900000211
Wherein
Figure GDA00037339325900000212
To represent
Figure GDA00037339325900000213
The conjugate transpose of (1);
further obtaining S by characteristic decomposition t Maximum eigenvalue λ of max,t And minimum eigenvalue λ min,t (ii) a Early failure detection index D t Calculated by the formula (3)
D t =λ max,tmin,t (3)。
Specifically, the Tracy-Widom distribution of the step four is expressed as:
for NxT W Matrix S of order t When N, T W → infinity and N/T W E [0, ∞ ]),
Figure GDA00037339325900000214
Figure GDA00037339325900000215
wherein F (x) is a Tracy-Widom cumulative distribution function, and P represents a probability.
Step four fault detection double threshold gamma 1 And gamma 2 Obtained according to the following method:
according to a given false alarm probability eta w And matrix dimensions N and T W Based on the Tracy-Widom distribution, the threshold value gamma is calculated according to the formulas (6) to (7) 1 And gamma 2
Figure GDA00037339325900000216
Figure GDA00037339325900000217
Wherein a and b represent the sample covariance matrix S, respectively t The theoretical infimum and supremum of the characteristic values,
Figure GDA0003733932590000031
Figure GDA0003733932590000032
F -1 (. cndot.) represents the inverse of the Tracy-Widom cumulative distribution function.
Specifically, the early failure detection index D in the fifth step t With fault detection dual threshold gamma 1 And gamma 2 The size relationship of (2) includes:
Figure GDA0003733932590000033
wherein, min (gamma) 12 ) Referred to as lower threshold, max (γ) 12 ) Referred to as upper threshold, respectively representing gamma 1 And gamma 2 Minimum and maximum values among the above.
The early failure detection results are expressed as:
Figure GDA0003733932590000034
wherein, P 0 When the fault detection index is between the upper threshold value and the lower threshold value, the probability that no fault occurs in the power grid is calculated by the formula (10)
Figure GDA0003733932590000035
D t =max(γ 12 ) The corresponding sampling time is the fault time.
The invention has the beneficial effects that:
1. the construction process of the double threshold takes the false alarm probability eta into account w And the influence of matrix dimension on the fault detection precision can be adjusted by adjusting the false alarm probability eta w And the width T of the sliding time window W And the threshold value is adjusted, so that higher flexibility is realized.
2. Compared with a single threshold analysis method, the method has the advantages that the lower threshold and the characteristic fuzzy processing between the upper threshold and the lower threshold can reduce the false alarm probability to a certain extent, and the method is specifically represented as follows: when the detection index is between the upper threshold and the lower threshold, the double-threshold method judges the system to be in a fault state according to a certain probability. In the single threshold method, only when the detection index is larger than the threshold value, it is determined that the system has disturbance. Therefore, the fault detection method of the invention can find the fault earlier, and particularly, the detection of the early fault is more accurate and advanced.
Drawings
Fig. 1 is a flowchart of a fault detection method according to the present invention.
Fig. 2 is a diagram of an IEEE39 node network topology.
Fig. 3 is a simulation graph of the fault detection method provided by the present invention under the condition of overload fault.
FIG. 4 is a graph of a simulation of the mean spectral radius method under overload fault.
FIG. 5 is a graph of a simulation of the spectral deviation method under overload fault.
FIG. 6 is a simulation graph of a sample covariance matrix maximum eigenvalue method under overload fault.
Detailed Description
The invention will be described in further detail below with reference to the figures and specific embodiments.
As shown in fig. 1, the method for detecting an early fault of a power grid provided by the present invention includes the following steps:
the method comprises the following steps: collecting power grid state data in real time, and arranging the data according to a time sequence to form a state matrix X;
step two: at each sampling time t, obtaining non-kilometers through data processing according to the constructed state matrix XSpecial matrix
Figure GDA0003733932590000041
Step three: according to the constructed non-metric matrix
Figure GDA0003733932590000042
Obtaining early failure detection index D through feature decomposition t
Step four: based on Tracy-Widom distribution, fault detection dual-threshold gamma is calculated according to given false alarm probability and dimensionality of window matrix 1 And gamma 2
Step five: according to the constructed early fault detection index D t With a threshold value gamma 1 And gamma 2 The magnitude relation of (2) detects the early failure of the power grid.
The dual-threshold early failure detection method proposed by the present invention is described in detail below by taking the IEEE39 node network shown in fig. 2 as a specific example. The power grid state data comprise node voltage, branch current, load active power, reactive power and the like, and can be selected according to analysis requirements. Each status data was analyzed separately. The type of fault we want to detect in the example is overload.
The method comprises the following steps: setting the fault type as overload, specifically, setting the load of the No. 8 bus in the experiment to be gradually increased from a rated value at the sampling time t of 500-600. The slow increase in load causes the bus voltage to change slowly over a small range and therefore the fault signature is not apparent early in the fault.
The IEEE39 node network shown in fig. 2 contains a total of 39 buses. The voltage of each bus is selected as a measurement state variable, namely N-39. The bus voltage is sampled for 1.5s by using the existing wide area measurement unit, if the sampling interval is 1ms, 1500 sampling moments are total, and a 39 × 1500 bus voltage matrix, namely the state matrix X in the step one, is obtained.
The data processing process of the second step comprises the following steps:
construction of a window matrix X using a sliding time window model t (ii) a According to the constructed window matrix X t Normalizing the state data by the row transformation of the formula (1) to obtain a non-metric matrix
Figure GDA0003733932590000043
Figure GDA0003733932590000044
The element(s) in (b) is represented by formula (1);
Figure GDA0003733932590000045
wherein i is 1,2, …, N, N is the constructed window matrix X t The number of rows of (2) represents the number of the collected state variables; j-1, 2, …, T W ,T W Is X t The number of columns of (a), i.e. the width of the sliding time window; x is the number of i,j Is X t The elements of (a) and (b),
Figure GDA0003733932590000046
is X t A row vector of (a);
Figure GDA0003733932590000047
for normalized matrix
Figure GDA0003733932590000048
The elements of (a) and (b),
Figure GDA0003733932590000049
is a matrix
Figure GDA00037339325900000410
A row vector of (a); mu (x) i ) Is X t Mean value of the row vectors of (a), σ (x) i ) Is X t The standard deviation of the row vector of (a);
Figure GDA00037339325900000411
for normalized matrix
Figure GDA00037339325900000412
The average of the row vectors of (a) is,
Figure GDA00037339325900000413
is a matrix
Figure GDA00037339325900000414
The standard deviation of the row vector of (1).
T W Typically several tens to several hundreds, T W Since the smaller the number of samples included in the matrix, the more sensitive the matrix is to noise signals, the less the asymptotic assumption (N, T) is satisfied in order to reduce the influence of noise on the state data when detecting an early fault whose fault signature is insignificant W → infinity and N/T W E [0, infinity)), selecting larger T as much as possible W
In an embodiment, the sliding time window width T is determined W At each sampling time t, a 39 × 100 non-metric matrix is obtained according to the above data processing procedure
Figure GDA00037339325900000415
The characteristic decomposition process of the third step comprises the following steps:
computing
Figure GDA00037339325900000416
Sample covariance matrix S of t And further obtaining a matrix S through characteristic decomposition t Maximum eigenvalue λ of max,t Minimum eigenvalue λ min,t
Figure GDA00037339325900000417
Wherein
Figure GDA0003733932590000051
To represent
Figure GDA0003733932590000052
The conjugate transpose of (c).
Further, an early failure detection index D is calculated t
D t =λ max,tmin,t (3)
The Tracy-Widom distribution of the step four is expressed as follows:
for NxT W Matrix S of order t ,λ max,t 、λ min,t Are respectively S t The maximum and minimum eigenvalues of (2), then when N, T W → infinity and N/T W Belongs to [0, ∞ ]),
Figure GDA0003733932590000053
Figure GDA0003733932590000054
wherein F (x) is a Tracy-Widom cumulative distribution function, and P represents a probability.
Step four fault detection double threshold gamma 1 And gamma 2 Obtained according to the following method:
according to a given false alarm probability eta w And matrix dimensions N and T W Based on the Tracy-Widom distribution, the threshold value gamma is calculated according to the formulas (6) to (7) 1 And gamma 2
Figure GDA0003733932590000055
Figure GDA0003733932590000056
Wherein a and b represent the sample covariance matrix S, respectively t Theoretical infimum and supremum of characteristic values, and
Figure GDA0003733932590000057
Figure GDA0003733932590000058
F -1 (. represents Tracy-Widom)The inverse of the distribution function is accumulated.
Wherein the false alarm probability eta w The fault probability is set according to actual analysis requirements, false alarm probability is increased when the false alarm probability is too high, false alarm probability is possibly too low, and false alarm is possibly missed, so that eta is obtained when higher fault detection probability is pursued in engineering practice w Should be relatively large. Determining false alarm probability eta in an embodiment w Obtaining double threshold value gamma based on Tracy-Widom distribution calculation 1 =2.9962,γ 2 =2.4230。
In step five, according to D t And gamma 1 And gamma 2 Detects whether the system has a fault.
Early failure detection index D t With fault detection dual threshold gamma 1 And gamma 2 The size relationship of (2) includes:
Figure GDA0003733932590000061
wherein, min (gamma) 12 ) Referred to as lower threshold, max (γ) 12 ) Referred to as upper threshold, respectively representing gamma 1 And gamma 2 Minimum and maximum values among the above.
Further, the early fault detection condition in step five is represented as:
Figure GDA0003733932590000062
wherein, P 0 When the fault detection index is between the upper threshold value and the lower threshold value, the probability that no fault occurs to the power grid is calculated by the formula (10).
Figure GDA0003733932590000063
The moment of failure is D t =max(γ 12 ) The corresponding sampling instant. The power grid protection device can immediately respond and execute corresponding fault protectionAnd (5) operating.
The probability judgment between the upper threshold and the lower threshold is called as "feature fuzzy" processing, wherein the "feature fuzzy" is relative to the determined state feature (fault/normal) of the power grid, and in the engineering practice, when the fault detection index is between the upper threshold and the lower threshold, whether the power grid has a fault is judged according to the probability, and at the moment, an engineer can determine whether to take protective measures according to experience.
FIG. 3 is a graph of the double threshold early fault detection method of the present invention under a set overload fault condition D t Curve line.
As can be seen from FIG. 3, in the normal state, D t <min(γ 12 ) And from the time t being 500, the bus voltage changes slowly as the load of node 8 increases, and at t 1 At the moment of time, satisfy
Figure GDA0003733932590000064
Then, D t Between the upper and lower thresholds to t 2 At the moment of time, satisfy
Figure GDA0003733932590000065
Therefore, the system can be judged to be at t through the double-threshold method 2 An overload fault occurs at a moment of time, and t 1 ~t 2 In P 0 The grid state is determined to be normal with a probability of 0.07, i.e. 1-P 0 And judging that the power grid state is abnormal by the probability of 0.93.
In order to verify the effectiveness of the fault detection method provided by the invention, the method provided by the invention is compared with three single threshold methods, and the method specifically comprises the following steps: mean Spectral Radius (MSR), spectral skewness, and sample covariance matrix Maximum Eigenvalue (MESCM). Simulation curves of the three methods under overload fault are respectively shown in fig. 4, fig. 5 and fig. 6. Wherein, the detection index of the MSR method is MSR, and the threshold value is Inner Radius; the detection index of the spectrum deviation method is d S The threshold value is
Figure GDA0003733932590000066
The detection index of the MESCM method is the most of the matrixLarge eigenvalue lambda max The threshold is γ. In the above single-threshold method, the intersection point of the detection index and the threshold is the fault time.
As can be seen from fig. 4, when detecting an overload fault with insignificant fault characteristics, the detection index of the MSR method does not have an intersection point with the threshold, that is, the MSR method fails; in FIGS. 5 and 6, both the spectral skewness method and the MESCM method are performed at t > t 2 The fault is detected at the moment, and compared with a double-threshold method, the fault is detected when t is t 2 The time for detecting faults is relatively lagged by the spectrum deviation method and the MESCM method.
The fault detection performance of the fault detection method based on the double threshold and the fault detection performance of the fault detection method based on the three single thresholds are summarized in table 1.
TABLE 1
Figure GDA0003733932590000071
As can be seen from table 1, compared with the single threshold method, the dual-threshold early fault detection method provided by the present invention can detect a fault earlier, and the calculation time is less.
The above embodiments are merely used to illustrate the present invention, and are not to be taken as limitations of the present invention, the applied objects are not limited to IEEE39 node network, the set fault type is not limited to overload, and changes and modifications to the above embodiments are within the scope of the claims of the present invention as long as they are within the scope of the present invention.

Claims (4)

1. A double-threshold power grid early fault detection method is characterized by comprising the following steps:
the method comprises the following steps: collecting power grid state data in real time, and arranging the data according to a time sequence to form a state matrix X;
step two: at each sampling time t, obtaining a non-metric matrix through data processing according to the constructed state matrix X
Figure FDA0003733932580000011
Step three: according to the constructed non-decimeter matrix
Figure FDA0003733932580000012
Obtaining early failure detection index D through feature decomposition t
Step four: based on Tracy-Widom distribution, fault detection dual-threshold gamma is calculated according to given false alarm probability and dimensionality of window matrix 1 And gamma 2
Step five: according to the constructed early fault detection index D t And a threshold value gamma 1 And gamma 2 The size relation of the grid fault detection module is used for detecting the early fault of the power grid;
the data processing process of the second step is as follows: construction of a window matrix X using a sliding time window model t (ii) a According to the constructed window matrix X t Normalizing the state data by the row transformation of the formula (1) to obtain a non-metric matrix
Figure FDA0003733932580000013
Figure FDA0003733932580000014
Wherein the element in (1) is represented by formula;
Figure FDA0003733932580000015
wherein i is 1,2, …, N, N is the constructed window matrix X t The number of rows of (2) represents the number of the collected state variables; j-1, 2, …, T W ,T W Is a window matrix X t The number of columns of (a), i.e. the width of the sliding time window; x is the number of i,j Representing a window matrix X t The elements of (a) and (b),
Figure FDA0003733932580000016
is a window matrix X t A row vector of (a);
Figure FDA0003733932580000017
representing normalized matrix
Figure FDA0003733932580000018
The elements of (a) and (b),
Figure FDA0003733932580000019
is a matrix
Figure FDA00037339325800000110
A row vector of (a); mu (x) i ) Is a matrix X t Mean value of the row vectors of (a), σ (x) i ) Is a window matrix X t The standard deviation of the row vector of (a);
Figure FDA00037339325800000111
for normalized matrix
Figure FDA00037339325800000112
The average of the row vectors of (a) is,
Figure FDA00037339325800000113
is a matrix
Figure FDA00037339325800000114
The standard deviation of the row vector of (a);
the characteristic decomposition process of the third step comprises the following steps: according to the constructed non-metric matrix
Figure FDA00037339325800000115
Calculating a sample covariance matrix S according to equation (2) t
Figure FDA00037339325800000116
Wherein
Figure FDA00037339325800000117
To represent
Figure FDA00037339325800000118
The conjugate transpose of (1);
further obtaining S through characteristic decomposition t Maximum eigenvalue λ of max,t And minimum eigenvalue λ min,t (ii) a Early failure detection index D t Calculated by the formula (3)
D t =λ max,tmin,t (3)
The Tracy-Widom distribution of the step four is expressed as follows:
for NxT W Matrix S of order t When N, T W → infinity and N/T W E [0, ∞ ]),
Figure FDA00037339325800000119
Figure FDA0003733932580000021
wherein F (x) is a Tracy-Widom cumulative distribution function, and P represents probability;
step four fault detection double threshold gamma 1 And gamma 2 Obtained according to the following method:
according to a given false alarm probability eta w And matrix dimensions N and T W Based on the Tracy-Widom distribution, the threshold value gamma is calculated according to the formulas (6) to (7) 1 And gamma 2
Figure FDA0003733932580000022
Figure FDA0003733932580000023
Wherein a and b represent the sample covariance matrix S, respectively t Feature(s)The theoretical infimum and supremum of values,
Figure FDA0003733932580000024
Figure FDA0003733932580000025
F -1 (. -) represents the inverse of the Tracy-Widom cumulative distribution function;
early fault detection index D in step five t With fault detection dual threshold gamma 1 And gamma 2 The size relationship of (2) includes:
Figure FDA0003733932580000026
wherein, min (gamma) 12 ) Referred to as lower threshold, max (γ) 12 ) Referred to as upper threshold, respectively representing gamma 1 And gamma 2 Minimum and maximum values of (d);
the early fault detection result in the step five is represented as:
Figure FDA0003733932580000027
wherein, P 0 When the fault detection index is between the upper threshold value and the lower threshold value, the probability that no fault occurs in the power grid is calculated by the formula (10)
Figure FDA0003733932580000031
2. The method as claimed in claim 1, wherein the grid state data of the first step is collected by a wide area measurement unit.
3. The method as claimed in claim 1, wherein the grid state data of the first step includes one or more of node voltage, branch current, load active power and reactive power, and each state data is analyzed separately.
4. A dual-threshold grid early fault detection method as claimed in claim 1, wherein in step five, D t =max(γ 12 ) The corresponding sampling time is the fault time.
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CN115032501A (en) * 2022-06-14 2022-09-09 无锡隆玛科技股份有限公司 Power grid anomaly detection method based on maximum characteristic value change rate of sample covariance matrix
CN115032502A (en) * 2022-06-14 2022-09-09 无锡隆玛科技股份有限公司 Maximum feature vector power grid abnormity positioning method
CN115358319B (en) * 2022-08-23 2023-06-16 天津大学 Self-adaptive fault-tolerant filtering method and system based on double-threshold detection

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201156070Y (en) * 2007-11-30 2008-11-26 北京市电力公司 Cable fault indicator
CN108196165A (en) * 2018-01-09 2018-06-22 贵州大学 Power grid abnormal state detection method based on sample covariance matrix maximum eigenvalue
CN109657613A (en) * 2018-12-19 2019-04-19 贵州大学 Large scale electric network abnormal load recognition methods based on power method and parallel computing
CN110568275A (en) * 2019-09-17 2019-12-13 国网福建省电力有限公司安溪县供电公司 open-phase fault studying and judging method and system based on public and private power distribution network variable data
CN110596533A (en) * 2019-09-12 2019-12-20 山东大学 Power distribution network single-phase earth fault section positioning method and system
CN110673060A (en) * 2019-09-25 2020-01-10 山东大学 Power distribution network fault diagnosis method based on synchronous phasor measurement and random matrix theory
CN111707901A (en) * 2020-04-21 2020-09-25 国网安徽省电力有限公司 Power distribution network single-phase grounding phase identification method based on voltage amplitude characteristics

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
PL1820034T3 (en) * 2004-11-18 2010-03-31 Powersense As Compensation of simple fiberoptic faraday effect sensors
US9019108B2 (en) * 2010-08-05 2015-04-28 General Electric Company Thermal measurement system for fault detection within a power generation system
CN206235698U (en) * 2016-10-28 2017-06-09 国家电网公司 A kind of electric network single-phase earth fault differentiates, isolates and resultant fault anticipation device
CN106447227A (en) * 2016-10-31 2017-02-22 国网上海市电力公司 Urban power grid abnormal state analyzing method and system

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201156070Y (en) * 2007-11-30 2008-11-26 北京市电力公司 Cable fault indicator
CN108196165A (en) * 2018-01-09 2018-06-22 贵州大学 Power grid abnormal state detection method based on sample covariance matrix maximum eigenvalue
CN109657613A (en) * 2018-12-19 2019-04-19 贵州大学 Large scale electric network abnormal load recognition methods based on power method and parallel computing
CN110596533A (en) * 2019-09-12 2019-12-20 山东大学 Power distribution network single-phase earth fault section positioning method and system
CN110568275A (en) * 2019-09-17 2019-12-13 国网福建省电力有限公司安溪县供电公司 open-phase fault studying and judging method and system based on public and private power distribution network variable data
CN110673060A (en) * 2019-09-25 2020-01-10 山东大学 Power distribution network fault diagnosis method based on synchronous phasor measurement and random matrix theory
CN111707901A (en) * 2020-04-21 2020-09-25 国网安徽省电力有限公司 Power distribution network single-phase grounding phase identification method based on voltage amplitude characteristics

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Research on Fault Diagnosis Technology for Power Grid Equipment Based on Spark;Peng Liu 等;《2018 IEEE 9th Annual Information Technology, Electronics and Mobile Communication Conference (IEMCON)》;20190117;第1126-1131页 *
基于MESCM算法的电网异常状态检测改进方法;张娟 等;《控制工程》;20200930;第28卷(第8期);第1641-1647页 *

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