CN108734599A - Power grid island effect detecting system and method - Google Patents

Power grid island effect detecting system and method Download PDF

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CN108734599A
CN108734599A CN201710251309.1A CN201710251309A CN108734599A CN 108734599 A CN108734599 A CN 108734599A CN 201710251309 A CN201710251309 A CN 201710251309A CN 108734599 A CN108734599 A CN 108734599A
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data
matrix
island effect
phasor
common connection
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郭媛君
刘育权
冯圣中
莫文雄
胡金星
吴国沛
王勇
王劲
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Shenzhen Institute of Advanced Technology of CAS
Guangzhou Power Supply Bureau Co Ltd
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Guangzhou Power Supply Bureau Co Ltd
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    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06QINFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
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    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/381Dispersed generators
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2203/00Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/20Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/388Islanding, i.e. disconnection of local power supply from the network

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Abstract

The present invention relates to a kind of power grid island effect detection methods, including:A. the phasor data at corresponding points of common connection is acquired by each phase amount detection unit;B. the data of above-mentioned acquisition are pre-processed;C. it according to above-mentioned pretreated data, is modeled using pca method;D. on the basis of pca method models, real-time data to be tested are detected, to determine whether to generate island effect.The invention further relates to a kind of power grid island effect detecting systems.Data used in the present invention more comprehensively, precision higher, and improve accuracy in detection.

Description

Power grid island effect detecting system and method
Technical field
The present invention relates to a kind of power grid island effect detecting system and methods.
Background technology
In distributed power generation grid-connected system, when main body power grid is due to electric fault, interruption maintenance or other human factors When interruption of power supply, each grid-connected system does not detect that power failure cuts off itself, and the isolated state of maintenance power supply, The island phenomenon that uncontrollable self-energizing is formd with load around, is referred to as island effect.When island effect occurs, electricity Net voltage or frequency will appear fluctuation, be easy to cause equipment damage;In addition, partial line road is still charged, it can serious prestige Coerce staff's personal safety.Effective island effect detection method is to safeguard distributed power generation grid-connected system and bulk power grid just The effective protection measure often run.
Existing island effect detection scheme is broadly divided into remote detection and local detection method.Remote detection is adopted due to data The use for collecting equipment and communication equipment, increases the complexity and installation maintenance cost of system, comes to the expansion bands of power grid certain Limitation.In local detection method, active method introduces interference signal to power grid, when being incorporated into the power networks, due to clamping down on for bulk power grid, disturbance Influence very little of the signal to inverter;And island effect is when occurring, the parameter (voltage, phase, frequency) of inverter output end by Disturbing signal effect deviates normal value and detects island effect when beyond given threshold.And passive means are to pass through detection Whether the terminal voltage amplitude, phase, frequency of points of common connection, harmonic wave occur abnormal to determine whether generating lonely when grid cut-off Island, since it does not introduce any interference signal to power grid, do not damage power quality and by the support of numerous researchers.
Existing island effect detection technique avoids the problem of conventional monitoring methods may cause to a certain extent, such as It avoids by introducing the shortcomings that interference is to destroy power quality into power grid, but still has following technical problem:One It is that the training of neural network needs a large amount of partial data, could improves accuracy of detection, and the SCADA that current power grid relies primarily on Device data amount is simultaneously little, and data acquisition when mainly for stable state, lacks the high-precision note of real-time transient data Record;Second is that the process object of wavelet transformation and neural network can only be synchronization that is single, can not being carried out at the same time in wide scope Detection, and rapid identification is carried out to island effect scene.
Invention content
In view of this, it is necessary to provide a kind of power grid island effect detecting system and method, can utilize multiple dimensioned Image information and vision significance obtain the information of image multi-dimensional degree, and carry out power grid island effect detection.
The present invention provides a kind of power grid island effect detecting system, including:Main network system, main circuit breaker, secondary breaker, Distributed grid-connected electricity generation system, local load demand and major network load demand, which is characterized in that the system further includes:With not Less than the high speed communication equipment that a phase amount detection unit is electrically connected, and be electrically connected respectively with the high speed communication equipment Global positioning system and data acquisition applications analysis center, data acquisition applications analysis center include acquisition module, pre- place Module, modeling module and detection module are managed, wherein:The acquisition module is used to acquire by each phase amount detection unit corresponding public Phasor data at tie point altogether;The preprocessing module is for pre-processing the data of above-mentioned acquisition;The modeling mould Block is used to, according to above-mentioned pretreated data, model using pca method;The detection module is used in pivot analysis On the basis of Method Modeling, real-time data to be tested are detected, to determine whether to generate island effect.
Wherein, the phasor data includes:Voltage magnitude, current amplitude and voltage phase angle.
The points of common connection is the public company of main network system, distributed grid-connected electricity generation system and major network load demand Contact.
The modeling module is specifically used for:
c1:By the main network system of above-mentioned acquisition, distributed grid-connected electricity generation system and major network load demand points of common connection The voltage magnitude at place, the phasor data of current amplitude and voltage phase angle, use phasor dataIt indicates;
c2:The PMU data composition matrix in N number of place is handled, data matrix X ∈ R are obtainedN×m
c3:The eigenvalue matrix of normalized treated data matrix X:
c4:Singular value decomposition is carried out by the variance matrix to data matrix to obtain:
X=U Λ0VT,
Wherein, Λ ∈ RN×NBe diagonal matrix, contain the characteristic value of the variance matrix, and by the variance matrix into Row is following to be decomposed:
c5:Raw data matrix is decomposed into load vectors p by pca methodiAnd score vector tiProduct it With along with residual error E:
Wherein, k indicates the pivot number chosen, for representing the maximum principal component space of variance in data;
c6:Calculate two statistical indicators that pca method is used for detection model:
T2Index:
And Q indexs:
c7:Detection control limit is calculated on the basis of the processing of normal data, due to T2Statistical value meets F distributions, presses According to confidence alpha, Statisti-cal control limitIt is calculated by following formula:
Wherein, k is pivot number, and m is the variable number of training data, and F (k, m-k, α) is indicated when data fit F distributions When, the probability value when degree of freedom is (m-k), and confidence level is α;
c8:Calculate the Statisti-cal control limit of Q values:
Wherein, θiIndicate that all remaining characteristic values correspond to the sum of 1,2,3 different power powers:
h0For intermediate result variable:
The detection module is specifically used for:By normal operation and containing island effect event real-time data to be tested Calculate new statistical indicator T2With Q values, then by new value of statistical indicant and Statisti-cal control limit be compared, generate Visual retrieval Chart detects the island effect of power grid according to the Visual retrieval chart;It is further confirmed that specifically by calculating contribution rate The phase amount detection unit of island effect occurs.
The present invention also provides a kind of power grid island effect detection methods, including:A. it is acquired by each phase amount detection unit Phasor data at corresponding points of common connection;B. the data of above-mentioned acquisition are pre-processed;C. according to above-mentioned pretreated Data are modeled using pca method;D. on the basis of pca method models, real-time data to be tested are examined It surveys, to determine whether to generate island effect.
Wherein, the phasor data includes:Voltage magnitude, current amplitude and voltage phase angle.
The points of common connection is the public company of main network system, distributed grid-connected electricity generation system and major network load demand Contact.
The step c detailed processes include:
c1:By the main network system of above-mentioned acquisition, distributed grid-connected electricity generation system and major network load demand points of common connection The voltage magnitude at place, the phasor data of current amplitude and voltage phase angle, use phasor dataIt indicates;
c2:The PMU data composition matrix in N number of place is handled, data matrix X ∈ R are obtainedN×m
c3:The eigenvalue matrix of normalized treated data matrix X:
c4:Singular value decomposition is carried out by the variance matrix to data matrix to obtain:
X=U Λ0VT,
Wherein, Λ ∈ RN×NBe diagonal matrix, contain the characteristic value of the variance matrix, and by the variance matrix into Row is following to be decomposed:
c5:Raw data matrix is decomposed into load vectors p by pca methodiAnd score vector tiProduct it With along with residual error E:
Wherein, k indicates the pivot number chosen, for representing the maximum principal component space of variance in data;
c6:Calculate two statistical indicators that pca method is used for detection model:
T2Index:
And Q indexs:
c7:Detection control limit is calculated on the basis of the processing of normal data, due to T2Statistical value meets F distributions, presses According to confidence alpha, Statisti-cal control limitIt is calculated by following formula:
Wherein, k is pivot number, and m is the variable number of training data, and F (k, m-k, α) is indicated when data fit F distributions When, the probability value when degree of freedom is (m-k), and confidence level is α;
c8:Calculate the Statisti-cal control limit of Q values:
Wherein, θiIndicate that all remaining characteristic values correspond to the sum of 1,2,3 different power powers:
h0For intermediate result variable:
The step d is specifically included:Normal operation and containing island effect event real-time data to be tested are pressed New statistical indicator T is calculated according to step c1 to step c62With Q values, then by new value of statistical indicant and above-mentioned steps c7 and step Statisti-cal control limit described in c8 is compared, and is generated Visual retrieval chart and is detected according to the Visual retrieval chart The island effect of power grid;The specific phase amount detection unit that island effect occurs is further confirmed that by calculating contribution rate.
Compared with prior art, the present invention mainly has the advantage that:
(1) present invention is the PMU data based on Wide Area Measurement System, and compared with prior art, data used are more Add comprehensive, precision higher, and since PMU technologies introduce the temporal information of the whole network synchronization, can include more fully dynamically Information improves the accuracy of island effect detection;
(2) pca method that uses of the present invention, is a kind of common process statistics method, be usually used in image procossing, The artificial aptitude area such as recognition of face, the at present application in power grid islet operation detection field or an innovation direction.It is main Element method can simultaneously be handled multiplely compared with the methods of the wavelet analysis that the prior art mostly uses greatly, neural network Quickly identification island effect scene is calculated according to pivot contribution rate in the real time data of point.It avoids at single object The limitation of reason and analysis, improves treatment effeciency from power grid overall operation, improves accuracy in detection.
Description of the drawings
Fig. 1 is the implementation environment schematic diagram of power grid island effect detecting system of the present invention;
Fig. 2 is the operation process chart of power grid island effect detection method preferred embodiment of the present invention;
Fig. 3 is the testing result schematic diagram that one embodiment of the invention pca method handles normal operation data;
Fig. 4 is that one embodiment of the invention pca method handles the testing result signal containing island effect event data Figure;
Fig. 5 is that one embodiment of the invention island effect scene judges result schematic diagram.
Specific implementation mode
Below in conjunction with the accompanying drawings and specific embodiment the present invention is described in further detail.
As shown in fig.1, being the implementation environment schematic diagram of power grid island effect detecting system of the present invention.
Power grid island effect detecting system of the present invention is established on the power supply system including distributed energy, packet It includes:Main network system 1, main circuit breaker 2, secondary breaker 31,32,33, distributed grid-connected electricity generation system (is distinguished in the present embodiment Also can be other kinds of for other distributed energies 43 such as wind generator system 41, solar power system 42, marine geothermal Distributed grid-connected electricity generation system), local load demand 51,52 and major network load demand 6;Further include:With phase amount detection unit (Phasor Measurement Unit, PMU) 71,72,73 high speed communication equipment 9 being electrically connected, and respectively with it is described The global positioning system (GPS) 8 and data acquisition applications analysis center 10 that high speed communication equipment 9 is electrically connected.Wherein:
The phase amount detection unit 71,72,73, be separately mounted to main network system 1 and distributed grid-connected electricity generation system 41, 42, at 43 points of common connection, for acquiring the phasor data at corresponding points of common connection.
The high speed communication equipment 9 is used to the phasor data of above-mentioned acquisition being transmitted to data acquisition applications analysis center 10。
The GPS8 is used to carry out the time synchronization of the whole network.
Data acquisition applications analysis center 10 is used to carry out analyzing processing to the data that high speed communication equipment 9 transmits, Realize the detection to power grid island effect.Data acquisition applications analysis center 10 includes the acquisition module being electrically connected successively 101, preprocessing module 102, modeling module 103 and detection module 104.Wherein:
The acquisition module 101 is for passing through each phase amount detection unit (Phasor Measurement Unit, PMU) Phasor data at the corresponding points of common connection of acquisition.The phasor data includes:Voltage magnitude, current amplitude and voltage-phase Angle.Specifically:
The phase amount detection unit acquires voltage magnitude, current amplitude and voltage phase angle at each points of common connection Phasor data, the phasor data by global positioning system (GPS) 8 carry out the whole network time synchronization, then pass through high speed Communication equipment 9 carries out data transmission, and analyzing processing is carried out in data acquisition applications analysis center 10.
Further, main network system 1, distributed grid-connected electricity generation system 41 and the major network load that PMU71 is acquired in real time are used The phasor data of voltage magnitude, current amplitude and voltage phase angle at 6 points of common connection of family;The main electricity that PMU72 is acquired in real time Voltage magnitude, current amplitude at 6 points of common connection of net system 1, distributed grid-connected electricity generation system 42 and major network load demand and The phasor data of voltage phase angle;Main network system 1, distributed grid-connected electricity generation system 43 and the major network that PMU73 is acquired in real time are negative The phasor data of voltage magnitude, current amplitude and voltage phase angle at load 6 points of common connection of user.
The preprocessing module 102 is for pre-processing the data of above-mentioned acquisition.Specifically:
The pretreatment includes:
Incomplete raw data file is removed from the data of above-mentioned acquisition, the incomplete raw data file has May be transmission fault, PMU is not keyed up or operation exception causes;
The normal reading PMU data at all points of common connection on the same day is chosen, imports analysis software MATLAB one by one In, and remove the data row for mark in PMU data, access time, voltage magnitude, current amplitude and voltage-phase Angle;
The time of selection is converted, is converted from general universal time coordinated (UTC, Universal Time Coordinated) It (is made within 24 hours) for the local time;
The voltage phase angle of selection is pre-processed, the vector form of voltage phase angle is converted into angle value, is convenient for Matrix calculates.
The modeling module 103 is used to, according to above-mentioned pretreated data, utilize pivot analysis (Principal Component Analysis, PCA) Method Modeling.It specifically includes:
Main network system 1, distributed grid-connected electricity generation system 41 and the major network load that phasor measurement unit 71 is acquired in real time The phasor data of voltage magnitude, current amplitude and voltage phase angle at 6 points of common connection of user, with vectorIndicate m time series sampled point of PMU71 continuous acquisitions here;
Likewise, the data of PMU72 devices acquisition can be expressed asIt can similarly obtain, other i-th The PMU of a place installation can obtain the phasor data of same format
According to the calculation features of pca method, the PMU data composition matrix in N number of place is handled, is counted According to matrix X ∈ RN×m
Pca method is handled, the eigenvalue matrix of normalized treated data matrix X:
By to the variance matrix of data matrix carry out singular value decomposition (Singular Value Decomposition, SVD it) obtains:
X=U Λ0VT,
Wherein, Λ ∈ RN×NIt is diagonal matrix, contains the characteristic value of the variance matrix;And by the variance matrix into Row is following to be decomposed:
Raw data matrix is decomposed into load vectors p by pca methodiAnd score vector tiThe sum of products again In addition residual error E:
Wherein, k indicates the pivot number chosen, for representing the maximum principal component space of variance in data.Under normal conditions, The 95% of data population variance can be included by choosing each pivot numbers of k;
Calculate two important statistical indicators that PCA methods are used for detection model:Hotelling's T2,
With Q indexs:
By PCA approach applications when process detects, detection control limit is calculated on the basis of the processing of normal data, due to T2Statistical value meets F distributions, and according to confidence degree α, (in the present embodiment, the confidence alpha is 95%) statistics control System limitIt is calculated by following formula:
Wherein, k is pivot number, and m is the variable number of training data, and F (k, m-k, α) is indicated when data fit F distributions When, the probability value when degree of freedom is (m-k), and confidence level is α;
Calculate the Statisti-cal control limit of Q values:
Wherein, θiIndicate that all remaining characteristic values correspond to the sum of 1,2,3 different power powers:
h0For intermediate result variable:
The detection module 104 is used on the basis of pca method models, and is examined to real-time data to be tested It surveys, to determine whether to generate island effect.Specifically:
On the basis of pca method models, by normal operation and contain the real-time to be detected of island effect event Data calculate new statistical indicator T by modeling module 1032It, then will be in new value of statistical indicant and modeling module 103 with Q values The Statisti-cal control limit is compared, and generates Visual retrieval chart, as shown in Figure 3 and Figure 4:
Fig. 3 shows the testing result to normal data, the T of new data2The control that statistical indicator is all indicated in dotted line Under limit, and Q statistics is substantially under control limit;
Fig. 4 show Principal Component Analysis Model to have recorded island effect generation PMU data be detected as a result, when Carve 16:51:In 41 oval regions shown in solid after the saltus step of first time, T2With Q simultaneously surmounted detection limit, and continue to when Between window terminate, successfully detect island effect;
In order to further confirm that the specific PMU that island effect occurs, knot as shown in Figure 5 can get by calculating contribution rate Fruit:
As can be seen that the PMU of site number the 4th contributes maximum to failure in Fig. 5, it is believed that be point of the positions PMU There is island effect in cloth electricity generation system, provides quick and easy and accurate testing result for Systems Operator, and assist determining Plan.
As shown in fig.2, being the operation process chart of power grid island effect detection method preferred embodiment of the present invention.
Step S1, it is public by each phase amount detection unit (Phasor Measurement Unit, PMU) acquisition correspondence Phasor data at tie point.The phasor data includes:Voltage magnitude, current amplitude and voltage phase angle.Specifically:
The phase amount detection unit acquires voltage magnitude, current amplitude and voltage phase angle at each points of common connection Phasor data, the phasor data by global positioning system (GPS) 8 carry out the whole network time synchronization, then pass through high speed Communication equipment 9 carries out data transmission, and analyzing processing is carried out in data acquisition applications analysis center 10.
Further, main network system 1, distributed grid-connected electricity generation system 41 and the major network load that PMU71 is acquired in real time are used The phasor data of voltage magnitude, current amplitude and voltage phase angle at 6 points of common connection of family;The main electricity that PMU72 is acquired in real time Voltage magnitude, current amplitude at 6 points of common connection of net system 1, distributed grid-connected electricity generation system 42 and major network load demand and The phasor data of voltage phase angle;Main network system 1, distributed grid-connected electricity generation system 43 and the major network that PMU73 is acquired in real time are negative The phasor data of voltage magnitude, current amplitude and voltage phase angle at load 6 points of common connection of user.
Step S2 pre-processes the data of above-mentioned acquisition.Specifically:
The pretreatment includes:
Incomplete raw data file is removed from the data of above-mentioned acquisition, the incomplete raw data file has May be transmission fault, PMU is not keyed up or operation exception causes;
The normal reading PMU data at all points of common connection on the same day is chosen, imports analysis software MATLAB one by one In, and remove the data row for mark in PMU data, access time, voltage magnitude, current amplitude and voltage-phase Angle;
The time of selection is converted, is converted from general universal time coordinated (UTC, Universal Time Coordinated) It (is made within 24 hours) for the local time;
The voltage phase angle of selection is pre-processed, the vector form of voltage phase angle is converted into angle value, is convenient for Matrix calculates.
Step S3 utilizes pivot analysis (Principal Component according to above-mentioned pretreated data Analysis, PCA) Method Modeling.Specifically comprise the following steps:
Step S31, the main network system 1 that phasor measurement unit 71 is acquired in real time, 41 and of distributed grid-connected electricity generation system The phasor data of voltage magnitude, current amplitude and voltage phase angle at 6 points of common connection of major network load demand, with vectorIndicate m time series sampled point of PMU71 continuous acquisitions here;
Step S32, likewise, the data of PMU72 devices acquisition can be expressed asSimilarly may be used , the PMU of other i-th of places installation can obtain the phasor data of same format
Step S33, according to the calculation features of pca method, at the PMU data composition matrix in N number of place Reason, obtains data matrix X ∈ RN×m
Step S34, handles pca method, the characteristic value square of normalized treated data matrix X Battle array:
Step S35 carries out singular value decomposition (Singular Value by the variance matrix to data matrix Decomposition, SVD) it obtains:
X=U Λ0VT,
Wherein, Λ ∈ RN×NIt is diagonal matrix, contains the characteristic value of the variance matrix;And by the variance matrix into Row is following to be decomposed:
Raw data matrix is decomposed into load vectors p by step S36 by pca methodiAnd score vector tiMultiply The sum of product adds residual error E:
Wherein, k indicates the pivot number chosen, for representing the maximum principal component space of variance in data, it is generally the case that The 95% of data population variance can be included by choosing each pivot numbers of k;
Step S37 calculates two important statistical indicators that PCA methods are used for detection model:Hotelling's T2,
With Q indexs:
Step S38 will calculate detection control by PCA approach applications when process detects on the basis of the processing of normal data System limit, due to T2Statistical value meets F distributions, and according to confidence degree α, (in the present embodiment, the confidence alpha is 95%), Statisti-cal control limitsIt is calculated by following formula:
Wherein, k is pivot number, and m is the variable number of training data, and F (k, m-k, α) is indicated when data fit F distributions When, the probability value when degree of freedom is (m-k), and confidence level is α;
Step S39 calculates the Statisti-cal control limit of Q values:
Wherein, θiIndicate that all remaining characteristic values correspond to the sum of 1,2,3 different power powers:
h0For intermediate result variable:
Step S4:On the basis of pca method models, real-time data to be tested are detected, to determine whether Generate island effect.Specifically:
On the basis of pca method models, by normal operation and contain the real-time to be detected of island effect event Data calculate new statistical indicator T according to step S31 to step S372With Q values, then by new value of statistical indicant and above-mentioned steps Statisti-cal control limit described in S38 and step S39 is compared, and generates Visual retrieval chart, as shown in Figure 3 and Figure 4:
Fig. 3 shows the testing result to normal data, the T of new data2The control that statistical indicator is all indicated in dotted line Under limit, and Q statistics is substantially under control limit;
Fig. 4 show Principal Component Analysis Model to have recorded island effect generation PMU data be detected as a result, when Carve 16:51:In 41 oval regions shown in solid after the saltus step of first time, T2With Q simultaneously surmounted detection limit, and continue to when Between window terminate, successfully detect island effect;
In order to further confirm that the specific PMU that island effect occurs, knot as shown in Figure 5 can get by calculating contribution rate Fruit:
As can be seen that the PMU of site number the 4th contributes maximum to failure in Fig. 5, it is believed that be point of the positions PMU There is island effect in cloth electricity generation system, provides quick and easy and accurate testing result for Systems Operator, and assist determining Plan.
Island effect detection method proposed by the present invention utilizes master by the PMU data acquired based on Wide Area Measurement System Element method carries out pivot analysis to the data under normal operational condition and establishes model, realizes the isolated island effect of online real time data It should quickly detect, carrying out easy failure contribution rate for the data limited more than monitoring and controlling calculates, and can determine island effect Scene.This invention takes full advantage of the Dynamic High-accuracy real time data based on Wide Area Measurement System, helps to improve Island effect accuracy in detection eliminates destruction of the interference of active detecting method introducing to power quality;Using pivot analysis side Method can simultaneously be detected the PMU data in multiple places, and the erroneous judgement that may be brought when avoiding single object handles helps Automation and the level of IT application are protected in improving smart grid distribution.
Although the present invention is described with reference to current better embodiment, those skilled in the art should be able to manage Solution, for above-mentioned better embodiment only for illustrating the present invention, protection domain not for the purpose of limiting the invention is any in the present invention Spirit and spirit within, any modification, equivalence replacement, improvement for being done etc., should be included in the present invention right protect Within the scope of shield.

Claims (10)

1. a kind of power grid island effect detecting system, including:Main network system, main circuit breaker, secondary breaker, distributed grid-connected hair Electric system, local load demand and major network load demand, which is characterized in that the system further includes:With a no less than phasor The high speed communication equipment that detection unit is electrically connected, and the global positioning system with high speed communication equipment electric connection respectively With data acquisition applications analysis center, data acquisition applications analysis center includes acquisition module, preprocessing module, modeling mould Block and detection module, wherein:
The acquisition module is used to acquire the phasor data at corresponding points of common connection by each phase amount detection unit;
The preprocessing module is for pre-processing the data of above-mentioned acquisition;
The modeling module is used to, according to above-mentioned pretreated data, model using pca method;
The detection module is used on the basis of pca method models, and is detected to real-time data to be tested, with true It is fixed whether to generate island effect.
2. the system as claimed in claim 1, which is characterized in that the phasor data includes:Voltage magnitude, current amplitude and Voltage phase angle.
3. system as claimed in claim 2, which is characterized in that the points of common connection be main network system, it is distributed simultaneously The points of common connection of net electricity generation system and major network load demand.
4. system as claimed in claim 3, which is characterized in that the modeling module is specifically used for:
c1:At the main network system of above-mentioned acquisition, distributed grid-connected electricity generation system and major network load demand points of common connection The phasor data of voltage magnitude, current amplitude and voltage phase angle, uses phasor dataIt indicates;
c2:The PMU data composition matrix in N number of place is handled, data matrix X ∈ R are obtainedN×m
c3:The eigenvalue matrix of normalized treated data matrix X:
c4:Singular value decomposition is carried out by the variance matrix to data matrix to obtain:
X=U Λ0VT,
Wherein, Λ ∈ RN×NIt is diagonal matrix, contains the characteristic value of the variance matrix, and the variance matrix is carried out such as Lower decomposition:
c5:Raw data matrix is decomposed into load vectors p by pca methodiAnd score vector tiThe sum of products again In addition residual error E:
Wherein, k indicates the pivot number chosen, for representing the maximum principal component space of variance in data;
c6:Calculate two statistical indicators that pca method is used for detection model:
T2Index:
And Q indexs:
c7:Detection control limit is calculated on the basis of the processing of normal data, due to T2Statistical value meets F distributions, according to confidence Spend α, Statisti-cal control limitIt is calculated by following formula:
Wherein, k is pivot number, and m is the variable number of training data, and F (k, m-k, α) is indicated when data fit F is distributed, Degree of freedom is (m-k), probability value when confidence level is α;
c8:Calculate the Statisti-cal control limit of Q values:
Wherein, θiIndicate that all remaining characteristic values correspond to the sum of 1,2,3 different power powers:
h0For intermediate result variable:
5. system as claimed in claim 4, which is characterized in that the detection module is specifically used for:
Normal operation and containing island effect event real-time data to be tested are calculated into new statistical indicator T2With Q values, then general New value of statistical indicant and Statisti-cal control limit are compared, and generate Visual retrieval chart, according to the Visual retrieval chart, Detect the island effect of power grid;
The specific phase amount detection unit that island effect occurs is further confirmed that by calculating contribution rate.
6. a kind of power grid island effect detection method, which is characterized in that this method comprises the following steps:
A. the phasor data at corresponding points of common connection is acquired by each phase amount detection unit;
B. the data of above-mentioned acquisition are pre-processed;
C. it according to above-mentioned pretreated data, is modeled using pca method;
D. on the basis of pca method models, real-time data to be tested are detected, to determine whether to generate isolated island Effect.
7. method as claimed in claim 6, which is characterized in that the phasor data includes:Voltage magnitude, current amplitude and Voltage phase angle.
8. the method for claim 7, which is characterized in that the points of common connection be main network system, it is distributed simultaneously The points of common connection of net electricity generation system and major network load demand.
9. method as claimed in claim 8, which is characterized in that the step c detailed processes include:
c1:At the main network system of above-mentioned acquisition, distributed grid-connected electricity generation system and major network load demand points of common connection The phasor data of voltage magnitude, current amplitude and voltage phase angle, uses phasor dataIt indicates;
c2:The PMU data composition matrix in N number of place is handled, data matrix X ∈ R are obtainedN×m
c3:The eigenvalue matrix of normalized treated data matrix X:
c4:Singular value decomposition is carried out by the variance matrix to data matrix to obtain:
X=U Λ0VT,
Wherein, Λ ∈ RN×NIt is diagonal matrix, contains the characteristic value of the variance matrix, and the variance matrix is carried out such as Lower decomposition:
c5:Raw data matrix is decomposed into load vectors p by pca methodiAnd score vector tiThe sum of products again In addition residual error E:
Wherein, k indicates the pivot number chosen, for representing the maximum principal component space of variance in data;
c6:Calculate two statistical indicators that pca method is used for detection model:
T2Index:
And Q indexs:
c7:Detection control limit is calculated on the basis of the processing of normal data, due to T2Statistical value meets F distributions, according to confidence Spend α, Statisti-cal control limitIt is calculated by following formula:
Wherein, k is pivot number, and m is the variable number of training data, and F (k, m-k, α) is indicated when data fit F is distributed, Degree of freedom is (m-k), probability value when confidence level is α;
c8:Calculate the Statisti-cal control limit of Q values:
Wherein, θiIndicate that all remaining characteristic values correspond to the sum of 1,2,3 different power powers:
h0For intermediate result variable:
10. method as claimed in claim 9, which is characterized in that the step d is specifically included:
Normal operation and containing island effect event real-time data to be tested are calculated newly according to step c1 to step c6 Statistical indicator T2With Q values, then the Statisti-cal control described in new value of statistical indicant and above-mentioned steps c7 and step c8 is limited and is carried out Compare, generates Visual retrieval chart and the island effect of power grid is detected according to the Visual retrieval chart;
The specific phase amount detection unit that island effect occurs is further confirmed that by calculating contribution rate.
CN201710251309.1A 2017-04-18 2017-04-18 Power grid island effect detecting system and method Pending CN108734599A (en)

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