CN109239523B - Active power distribution network fault positioning method based on improved Karrenbauer transformation - Google Patents

Active power distribution network fault positioning method based on improved Karrenbauer transformation Download PDF

Info

Publication number
CN109239523B
CN109239523B CN201810773762.3A CN201810773762A CN109239523B CN 109239523 B CN109239523 B CN 109239523B CN 201810773762 A CN201810773762 A CN 201810773762A CN 109239523 B CN109239523 B CN 109239523B
Authority
CN
China
Prior art keywords
fault
matrix
section
distribution network
power distribution
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201810773762.3A
Other languages
Chinese (zh)
Other versions
CN109239523A (en
Inventor
姜惠兰
陈娟
贾燕琪
张弛
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tianjin University
Original Assignee
Tianjin University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tianjin University filed Critical Tianjin University
Priority to CN201810773762.3A priority Critical patent/CN109239523B/en
Publication of CN109239523A publication Critical patent/CN109239523A/en
Application granted granted Critical
Publication of CN109239523B publication Critical patent/CN109239523B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/088—Aspects of digital computing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
    • 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
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
    • Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
    • Y04S10/52—Outage or fault management, e.g. fault detection or location

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Locating Faults (AREA)

Abstract

The invention relates to an active power distribution network fault positioning method based on improved Karrenbauer transformation, which comprises the steps of obtaining an active power distribution network impedance matrix by a control center, diagonalizing the impedance matrix by using a standard Karrenbauer transformation matrix to obtain a primary transformation matrix, calculating the improved Karrenbauer transformation matrix, dividing the active power distribution network into a plurality of sections, transforming by using the improved Karrenbauer transformation matrix to obtain α, β and 0 mode currents, calculating a α mode fault additional current phase angle difference by a local data processing device and sending the phase angle difference to the control center to generate a real-time system state information matrix, and judging whether each section has a fault or not by the control center.

Description

Active power distribution network fault positioning method based on improved Karrenbauer transformation
Technical Field
The invention belongs to the technical field of fault location of an active power distribution network containing a distributed power supply, and particularly relates to a novel method for realizing fault location of the active power distribution network based on improved Karrenbauer transformation by considering the asymmetric characteristic of line parameters of the power distribution network.
Background
Under the background of increasingly tense world primary energy sources and more serious problems of energy conservation and emission reduction, Distributed Generation (DG) technology is generally concerned by people with unique economy and environmental protection.
The distributed power generation technology is a generator set which is connected into a module type, clean, pollution-free and small in capacity on the basis of power supply of a large power grid, and is generally installed near users, such as a wind driven generator, a photovoltaic cell, a fuel cell and the like. After the DGs are connected to the grid, the power distribution network is converted from a traditional radial single-ended power supply network into a two-end/multi-end power supply network. Most of the traditional fault positioning strategies are based on the unidirectional tide characteristic of a radial power distribution network, the structure of the power distribution network is changed by the access of DGs, and the distribution of short-circuit current is changed greatly, so that the fault positioning result is inevitably influenced. In addition, the medium and low voltage distribution network does not adopt three-phase transposition measures any more, so that three-phase line parameters of the distribution network are asymmetric, and the difficulty in accurately positioning faults of the active distribution network is increased.
At present, most researches on fault location of a power distribution network containing DGs ignore the asymmetry of line parameters of the power distribution network, and directly treat an asymmetric network as a symmetric network; and many studies do not deeply discuss the influence of the existence of the fault point transition resistance on the positioning, which limits the practicability of the fault positioning scheme. In addition, some power distribution network fault location methods, such as matrix algorithms and intelligent algorithms, have the problems that the fault location time is long and the fault section location cannot be realized quickly.
Disclosure of Invention
The invention provides a new active power distribution network fault positioning method based on improved Karrenbauer transformation, and aims to solve the problems that after a power distribution network is connected into a DG, the positioning accuracy of a traditional fault positioning scheme is reduced, the efficiency is low, and three-phase parameters of the power distribution network are asymmetric. According to the characteristics of the parameter matrix of the active power distribution network and the characteristics of fault current, a phase-mode transformation method and a fault location criterion which are suitable for high-precision decoupling of a three-phase network of the non-transposition power distribution network are found, and rapid and precise fault location of the DG-containing active power distribution network is achieved. The technical scheme is as follows:
an active power distribution network fault positioning method based on improved Karrenbauer transformation comprises the following steps:
(1) the control center obtains an impedance matrix Z of the active power distribution network, wherein the form of the Z is shown as a formula (1), and diagonalization processing is performed on the impedance matrix by using a standard Karrenbauer transformation matrix to obtain a primary transformation matrix Y:
Figure BDA0001730909310000011
Y＝K-1ZK (2)
correcting Karrenbauer matrix K for preliminary transformation matrix Y2And carrying out diagonalization treatment to obtain a diagonalized matrix lambda with higher precision:
λ＝(K2)-1YK2＝(KK2)-1Z(KK2) (3)
wherein:
Figure BDA0001730909310000021
let S be KK2S is an improved Karrenbauer transformation matrix;
(2) dividing an active power distribution network into a plurality of sections, respectively labeling each section and nodes at two ends of the section, synchronously acquiring three-phase currents at the nodes at two ends of each section by using a protection measuring device at the nodes at two ends of each section, filtering, and obtaining α, β and 0-mode currents by using improved Karrenbauer transformation matrix transformation;
(3) the local data processing device calculates the fault additional current after taking α mode current at two ends of the section
Figure BDA0001730909310000022
α mode fault additional current phase angle theta at two ends of a section is obtained by fast Fourier transform1(i)、θ1(j) And calculating the additional current phase angle difference of the section α mode fault:
Δθ1(i,j)＝θ1(i)-θ1(j)
obtained Delta theta1(i, j) the data is sent to the control center by communication, and the control center receives and stores delta theta1(i, j) generating a real-time system state information matrix;
(4) the threshold value delta for judging the fault of the control center section is 7.5-8 degrees, whether the element value in the system state information matrix is larger than the threshold value or not is judged, and if a certain element is lower than the threshold value, the section is not in fault; if some element is larger than the threshold value, judging that the section has a fault;
(5) and the control center immediately processes the fault after detecting and positioning the fault, and sends action signals to the protection devices at two ends of the fault section to isolate the fault.
Compared with the prior art, the scheme provides a new active power distribution network fault positioning method based on improved Karrenbauer transformation on the basis of fully considering distributed power supply access, and the following beneficial effects are achieved:
(1) aiming at the characteristic of asymmetric parameters of the power distribution network line, the phase-mode conversion method based on the improved Karrenbauer conversion can realize the high-precision decoupling of the asymmetric network. The transformation method has the advantages of simple calculation process, small calculation amount and high decoupling precision.
(2) And deducing a fault positioning criterion of the active power distribution network section on the basis of high-precision decoupling of the asymmetric network. The criterion is not influenced by transition resistance, accords with the practical characteristics of parameters of the power distribution network, can realize rapid positioning of the active power distribution network, does not need to be additionally provided with directional elements, and has higher reliability.
Drawings
FIG. 1 α model composite sequence net equivalent decomposition circuit, (a) α model normal state, (b) α model fault additional state
FIG. 2 is a schematic diagram of a method for locating faults in an active power distribution network
FIG. 3 is a diagram of a power distribution network simulation system
Detailed Description
The method comprises the following steps of firstly, according to the characteristic that line parameters of the power distribution network are asymmetric due to no transposition and have the central symmetry of a parameter impedance matrix, carrying out standard Karrenbauer transformation on the line impedance matrix of the power distribution network to increase the sparsity of the matrix, providing a premise for accurate decoupling, further carrying out diagonalization treatment on a primary transformation matrix to obtain a Karrenbauer correction matrix, thereby obtaining a phase-mode transformation matrix capable of realizing the high-accuracy decoupling of the three phases of the power distribution network without transposition, namely improving the Karrenbauer matrix, and on the basis of the high-accuracy decoupling of the three-phase network, deducing the criterion of fault location of a section of the active power distribution network, which is not influenced by transition resistance, by theoretically analyzing the phase angle difference of α mode fault additional current components after the three-phase decoupling of the active power distribution network, thereby realizing the accurate fault location of the power distribution network with the distributed power, wherein the scheme comprises the following steps:
1. improved Karrenbauer transformation for realizing accurate decoupling of asymmetric network
In practice, three-phase conductors of a medium-low voltage distribution network are usually arranged horizontally or vertically, and the distances between the three phases are not completely equal any more, so that the line parameters of the system are asymmetric. Analysis shows that the arrangement form of the medium and low voltage distribution network leads enables the impedance matrix of the line to be in the form of a central symmetric matrix:
Figure BDA0001730909310000031
aiming at the characteristic that the line parameters are asymmetric but have the central symmetry of a parameter impedance matrix caused by no transposition of a power distribution network, the impedance matrix is subjected to standard Karrenbauer transformation to increase the sparsity of the matrix, and a premise is provided for accurate decoupling; on the basis, further diagonalization processing is carried out on the preliminary transformation matrix to obtain a correction matrix, and then a phase-mode transformation matrix capable of realizing three-phase high-precision decoupling of the transposition-free power distribution network is obtained, namely the Karrenbauer matrix is improved.
(1) Standard Karrenbauer transformation
The Karrenbauer transformation matrix is known as follows:
Figure BDA0001730909310000032
mathematically, the decoupling process of the impedance matrix, i.e. the process of seeking the phase-mode transformation matrix S to realize the impedance matrix Z diagonalization, is expressed as S by the formula-1ZS ═ λ. The impedance matrix Z is preliminarily transformed by using a standard Karrenbauer transformation matrix to obtain:
Figure BDA0001730909310000033
Figure BDA0001730909310000041
therefore, for the medium and low voltage distribution network line impedance matrix in the form shown in the formula (1), the coupling degree between the α mode component and the β mode component is weakened to a certain extent through Karrenbauer transformation.
(2) Improved Karrenbauer transformation
As can be seen from the formula (3), in order to realize the decoupling of the matrix Z finally, only the decoupling of the matrix Y needs to be realized, that is to say, the decoupling is realized through the preliminary Karrenbauer transformationThe decoupling problem of Z can then be further translated into the decoupling problem of Y: seeking a phase-mode transformation matrix K2The diagonalization of the matrix Y is achieved. The mathematical expression is as follows:
(K2)-1YK2＝λ (5)
to ask for the modulus transformation matrix K2First, starting with solving the eigenvalue λ:
Figure BDA0001730909310000042
the characteristic value can be determined from equation (6):
Figure BDA0001730909310000043
thus, the phase-mode transformation matrix for Y is:
Figure BDA0001730909310000044
combining the above two transformations, we can obtain:
Figure BDA0001730909310000051
thus, the impedance matrix Z is diagonalized with a higher accuracy by the transformation. The new phase-mode transformation matrix is S-KK2，K2Can be regarded as the correction of the original Karrenbauer transformation matrix, which is called as the corrected Karrenbauer matrix. New phase-mode transformation matrix S-KK2The method is called an improved Karrenbauer transformation matrix.
2. Power distribution network section fault positioning criterion based on improved Karrenbauer transformation
(1) Phase angle difference of additional current of α mode network fault in internal fault
As can be seen from the principle of superposition, the α -mode equivalent sequence diagram can be decomposed into two parts, namely a normal state and a fault additional state, which are respectively shown in FIGS. 1(a) and (b), wherein the reference direction of the fault additional current and the normal current are defined
Figure BDA0001730909310000059
In the same direction.
From fig. 1(b) the fault added current across the segment can be calculated as:
Figure BDA0001730909310000052
in the formula:
Figure BDA0001730909310000053
since the parameters of the line are evenly distributed along the line, the parameters are concentrated
Figure BDA0001730909310000054
Can be expressed as
Figure BDA0001730909310000055
Figure BDA0001730909310000056
In the form of (1), Z represents the impedance per unit length of the line. After substituting the formula (11), the finishing can be obtained:
Figure BDA0001730909310000057
the phase angle difference of the fault additional current can be inferred as:
Figure BDA0001730909310000058
from equation (13), it can be seen that for the α mode network, when the in-zone fault occurs, the phase angle difference of the fault additional current is 180 °.
(2) Phase angle difference of α mode network fault additional current in external fault
When a fault occurs outside the section, the current passing through the head end and the tail end of the section is the same, so that the phase angle difference of the α mode fault additional current is 0 degree at the moment.
From the above analysis, it is found that the phase angle difference of the α mode fault additional current is 180 ° when a fault occurs inside the block, and the phase angle difference of the α mode fault additional current is 0 ° when a fault occurs outside the block.
In consideration of the measurement errors and the calculation errors of the phase-to-analog conversion which may be present in practice, a threshold value δ is set for the fault criterion, and a fault is only detected in this section if the fault component current phase angle difference is greater than this threshold value. The angular error of the current transformer is considered, the general load is selected according to a 10% error curve and is considered as 7 degrees; the calculation error can be considered as 0.5-1 deg.. Therefore, the threshold value of the criterion is generally 7.5-8 degrees.
Therefore, the fault location criterion of the active power distribution network is shown as the formula (14):
Figure BDA0001730909310000061
3. effect of transition resistance on Fault location
The transition resistance affects the additional impedance for the network after phase-mode conversion, so the transition resistance only changes the value of the additional impedance for α modes, and the formula (13) shows that delta theta1(i,j)＝arg(-k2/k1) And is independent of the transition resistance, so the fault criterion based on the α mode fault additional current phase angle difference is not influenced by the transition resistance.
In order to verify the effectiveness of the fault location strategy provided by the present invention, a three-phase asymmetric active power distribution network example is selected, as shown in fig. 3. A corresponding simulation model is built in Matlab/Simulink.
The line impedance matrix is:
Figure BDA0001730909310000062
(1) impedance matrix decoupling
The impedance matrix was decoupled using a symmetric component method, with the following results:
Figure BDA0001730909310000063
decoupling the impedance matrix using an improved Karrenbauer transformation, the results are as follows:
Figure BDA0001730909310000071
comparing the two decoupling results, it is found that: for the parameter asymmetric matrix, the capability of weakening the three-phase coupling degree by a symmetric component method is smaller, and the improved Karrenbauer transformation provided by the invention can realize the impedance matrix decoupling with higher precision.
(2) Fault location simulation
Table 1 shows the simulation of the improved Karrenbauer transform based fault location method under different transition resistances at different segments. By contrast, when different types of faults occur in different sections, whether transition resistance exists or not, the fault location method can achieve accurate fault section location.
TABLE 1 Fault location results based on improved Karrenbauer transformation
Figure BDA0001730909310000072
When the values of the transition resistances are different, and the section 3 has a fault, the values of α mode fault component current phase angle differences of the section based on the improved Karrenbauer transformation are shown in table 2.
TABLE 2 phase angle difference (Unit/0) of fault component current for different transition resistances
Figure BDA0001730909310000073

Claims (1)

1. An active power distribution network fault positioning method based on improved Karrenbauer transformation comprises the following steps:
(1) the control center obtains an impedance matrix Z of the active power distribution network, wherein the form of the Z is shown as a formula (1), and diagonalization processing is performed on the impedance matrix by using a standard Karrenbauer transformation matrix to obtain a primary transformation matrix Y:
Figure FDA0002233295650000011
Figure FDA0002233295650000012
wherein
Figure FDA0002233295650000013
Correcting Karrenbauer matrix K for preliminary transformation matrix Y2And carrying out diagonalization treatment to obtain a diagonalized matrix lambda with higher precision:
λ＝(K2)-1YK2＝(KK2)-1Z(KK2) (3)
wherein:
Figure FDA0002233295650000014
let S be KK2S is an improved Karrenbauer transformation matrix;
(2) dividing an active power distribution network into a plurality of sections, respectively labeling each section and nodes at two ends of the section, synchronously acquiring three-phase currents at the nodes at two ends of each section by using a protection measuring device at the nodes at two ends of each section, filtering, and obtaining α, β and 0-mode currents by using improved Karrenbauer transformation matrix transformation;
(3) the local data processing device calculates the fault additional current after taking α mode current at two ends of the section
Figure FDA0002233295650000021
α mode fault additional current phase angle theta at two ends of a section is obtained by fast Fourier transform1(i)、θ1(j) And calculating the additional current phase angle difference of the section α mode fault:
Δθ1(i,j)＝θ1(i)-θ1(j)
obtained Delta theta1(i, j) the data is sent to the control center by communication, and the control center receives and stores delta theta1(i, j) generating a real-time system state information matrix;
(4) the threshold value delta for judging the fault of the control center section is 7.5-8 degrees, whether the element value in the system state information matrix is larger than the threshold value or not is judged, and if a certain element is lower than the threshold value, the section is not in fault; if some element is larger than the threshold value, judging that the section has a fault;
(5) and the control center immediately processes the fault after detecting and positioning the fault, and sends action signals to the protection devices at two ends of the fault section to isolate the fault.
CN201810773762.3A 2018-07-15 2018-07-15 Active power distribution network fault positioning method based on improved Karrenbauer transformation Active CN109239523B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810773762.3A CN109239523B (en) 2018-07-15 2018-07-15 Active power distribution network fault positioning method based on improved Karrenbauer transformation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810773762.3A CN109239523B (en) 2018-07-15 2018-07-15 Active power distribution network fault positioning method based on improved Karrenbauer transformation

Publications (2)

Publication Number Publication Date
CN109239523A CN109239523A (en) 2019-01-18
CN109239523B true CN109239523B (en) 2020-03-24

Family

ID=65072675

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810773762.3A Active CN109239523B (en) 2018-07-15 2018-07-15 Active power distribution network fault positioning method based on improved Karrenbauer transformation

Country Status (1)

Country Link
CN (1) CN109239523B (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110456133B (en) * 2019-08-27 2021-11-09 河海大学 Cable parameter determination method based on phase-mode transformation
JP2023500471A (en) 2019-10-28 2023-01-06 エンフェーズ エナジー インコーポレイテッド Method and apparatus for microgrid tertiary control with integrated overcurrent protection
CN112180165B (en) * 2020-09-17 2022-03-29 国网湖南省电力有限公司供电服务中心（计量中心） Low-voltage power supply line impedance measuring and calculating method based on intelligent meter and terminal operation data
CN113009276B (en) * 2021-03-04 2022-05-31 国网宁夏电力有限公司电力科学研究院 Intelligent power distribution network fault positioning method based on impedance matrix
CN116359674B (en) * 2023-06-01 2023-09-12 昆明理工大学 Active power distribution network fault positioning method and system based on fault transient signals

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101299538A (en) * 2008-04-08 2008-11-05 昆明理工大学 Cable-aerial mixed line fault travelling wave ranging method
US7969155B2 (en) * 2007-07-03 2011-06-28 Thomas & Betts International, Inc. Directional fault current indicator
CN103809079A (en) * 2014-02-17 2014-05-21 华北电力大学 Double-end high frequency impedance type fault ranging method suitable for direct current distribution network
CN104267271A (en) * 2014-08-27 2015-01-07 华北电力大学 Circuit and method for quickly obtaining dynamic parameters of power electronic device
CN105826907A (en) * 2016-05-11 2016-08-03 天津大学 Three-phase permanent fault judgment method for hybrid power transmission line with shunt reactors
CN104297629B (en) * 2014-08-19 2017-09-12 中国科学院电工研究所 The section fault detection of power distribution network containing distributed power source and localization method
CN107329045A (en) * 2017-07-14 2017-11-07 国网上海市电力公司 Distribution Network Failure least square location algorithm
CN107505534A (en) * 2017-07-14 2017-12-22 国网上海市电力公司 Distribution Network Failure genetic search localization method
CN107870287A (en) * 2017-11-08 2018-04-03 云南电力试验研究院(集团)有限公司 A kind of localization method of distribution network failure

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7969155B2 (en) * 2007-07-03 2011-06-28 Thomas & Betts International, Inc. Directional fault current indicator
CN101299538A (en) * 2008-04-08 2008-11-05 昆明理工大学 Cable-aerial mixed line fault travelling wave ranging method
CN103809079A (en) * 2014-02-17 2014-05-21 华北电力大学 Double-end high frequency impedance type fault ranging method suitable for direct current distribution network
CN104297629B (en) * 2014-08-19 2017-09-12 中国科学院电工研究所 The section fault detection of power distribution network containing distributed power source and localization method
CN104267271A (en) * 2014-08-27 2015-01-07 华北电力大学 Circuit and method for quickly obtaining dynamic parameters of power electronic device
CN105826907A (en) * 2016-05-11 2016-08-03 天津大学 Three-phase permanent fault judgment method for hybrid power transmission line with shunt reactors
CN107329045A (en) * 2017-07-14 2017-11-07 国网上海市电力公司 Distribution Network Failure least square location algorithm
CN107505534A (en) * 2017-07-14 2017-12-22 国网上海市电力公司 Distribution Network Failure genetic search localization method
CN107870287A (en) * 2017-11-08 2018-04-03 云南电力试验研究院(集团)有限公司 A kind of localization method of distribution network failure

Also Published As

Publication number Publication date
CN109239523A (en) 2019-01-18

Similar Documents

Publication Publication Date Title
CN109239523B (en) Active power distribution network fault positioning method based on improved Karrenbauer transformation
Huang et al. Multiple open-circuit fault diagnosis based on multistate data processing and subsection fluctuation analysis for photovoltaic inverter
CN109557421B (en) Multi-branch distribution network fault location method based on initial traveling wave time difference relation
CN114172412B (en) Parameter-free model prediction current control method for double three-phase permanent magnet motor
CN109494724B (en) LU decomposition-based large power grid Thevenin equivalent parameter online identification method
CN104794531A (en) MDCOPF (modified direct current optimal power flow) method based on grid loss equivalent load model
CN110609213B (en) MMC-HVDC power transmission line high-resistance grounding fault positioning method based on optimal characteristics
CN110927519A (en) Active power distribution network fault positioning method based on mu PMU measurement value
CN112018784B (en) Subsynchronous resonance tracing method based on synchronous phasor measurement data
CN110880764B (en) Fault processing method for unbalanced distribution network containing inversion type distributed power supply
CN107505534B (en) Distribution network fault genetic search positioning method
CN104182644A (en) Power distribution network state estimation method fusing distributed generation characteristics
CN109858061B (en) Power distribution network equivalence and simplification method for voltage power sensitivity estimation
CN105305392B (en) Short circuit calculation symmetrical component method suitable for the type IIDG power distribution network of control containing voltage
CN109638892B (en) Photovoltaic power station equivalent modeling method based on improved fuzzy clustering algorithm
CN103825270A (en) Three-phase state estimation jacobi matrix constant treatment method of power distribution network
CN113985210B (en) Voltage sag domain calculation method considering voltage sag amplitude and duration
CN113820564B (en) Fault detection method suitable for source network load storage complex power grid
CN112670966B (en) Self-adaptive current protection method for photovoltaic power distribution network
CN113991652A (en) Data-driven multi-output calculation method for short-circuit current of IIDG-containing power distribution network
CN113553538A (en) Recursive correction hybrid linear state estimation method
CN110007195A (en) SCADA bad data elimination method and system based on transmission line of electricity current imbalance amount
CN103928941A (en) Analytic solution method for aggregation of generators
Yang et al. Fault current constrained impedance-based method for high resistance ground fault location in distribution grid
CN113721115B (en) Single-phase grounding fault positioning method for neutral point flexible grounding power distribution network

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant