CN109524982B - AC/DC power grid transient stability risk assessment method - Google Patents
AC/DC power grid transient stability risk assessment method Download PDFInfo
- Publication number
- CN109524982B CN109524982B CN201811518505.1A CN201811518505A CN109524982B CN 109524982 B CN109524982 B CN 109524982B CN 201811518505 A CN201811518505 A CN 201811518505A CN 109524982 B CN109524982 B CN 109524982B
- Authority
- CN
- China
- Prior art keywords
- risk assessment
- power grid
- fault
- direct current
- alternating current
- 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
Links
- 230000001052 transient effect Effects 0.000 title claims abstract description 103
- 238000012502 risk assessment Methods 0.000 title claims abstract description 97
- 238000000034 method Methods 0.000 title claims abstract description 64
- 238000004364 calculation method Methods 0.000 claims abstract description 14
- 238000011156 evaluation Methods 0.000 claims abstract description 11
- 238000005070 sampling Methods 0.000 claims description 62
- 238000004088 simulation Methods 0.000 claims description 29
- 238000012544 monitoring process Methods 0.000 claims description 6
- 238000005316 response function Methods 0.000 claims description 6
- 238000007619 statistical method Methods 0.000 claims description 6
- 230000000737 periodic effect Effects 0.000 claims description 2
- 230000005540 biological transmission Effects 0.000 abstract description 10
- 238000004458 analytical method Methods 0.000 abstract description 3
- 238000005259 measurement Methods 0.000 abstract description 3
- 238000013473 artificial intelligence Methods 0.000 abstract description 2
- 238000006243 chemical reaction Methods 0.000 description 5
- 230000001687 destabilization Effects 0.000 description 5
- 238000004891 communication Methods 0.000 description 2
- 238000012804 iterative process Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000012821 model calculation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION 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
- G06Q10/00—Administration; Management
- G06Q10/06—Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
- G06Q10/063—Operations research, analysis or management
- G06Q10/0635—Risk analysis of enterprise or organisation activities
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION 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
- G06Q50/00—Information and communication technology [ICT] specially adapted for implementation of business processes of specific business sectors, e.g. utilities or tourism
- G06Q50/06—Energy or water supply
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
Landscapes
- Business, Economics & Management (AREA)
- Engineering & Computer Science (AREA)
- Human Resources & Organizations (AREA)
- Economics (AREA)
- Strategic Management (AREA)
- Tourism & Hospitality (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Theoretical Computer Science (AREA)
- Marketing (AREA)
- Entrepreneurship & Innovation (AREA)
- General Physics & Mathematics (AREA)
- General Business, Economics & Management (AREA)
- Operations Research (AREA)
- Development Economics (AREA)
- Quality & Reliability (AREA)
- Educational Administration (AREA)
- Game Theory and Decision Science (AREA)
- Public Health (AREA)
- Water Supply & Treatment (AREA)
- General Health & Medical Sciences (AREA)
- Primary Health Care (AREA)
- Power Engineering (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention discloses an AC/DC system transient stability risk assessment method, and belongs to the crossing field of the relay protection field and the artificial intelligence field of a power system transmission line. The invention adopts real-time measurement information under the large disturbance state of the direct current control system to carry out parallel analysis and evaluation of the rapid hypothetical fault set so as to obtain a continuous commutation failure risk estimation value of the disturbance based on the hypothetical fault set. The method provided by the invention can quickly evaluate the risk of continuous commutation failure of the direct current transmission system based on the measurement information after the alternating current disturbance occurs, overcomes the problem that the running risk of the direct current transmission system is difficult to evaluate, accelerates the calculation speed under the engineering field application based on the analysis of the equivalent model and the parallel calculation of the direct current converter station, and has wide engineering application prospect.
Description
Technical Field
The invention belongs to the technical field of power system stability control, relates to crossing of relay protection and artificial intelligence of a power transmission line of a power system, and particularly relates to a direct current system running state risk assessment method of an alternating current-direct current hybrid system.
Background
With the rapid development of direct-current transmission technology in China, an alternating-current and direct-current hybrid transmission system with the largest scale and the highest voltage level in the world is formed in China. The converter valve of LCC-HVDC (based on the high-voltage direct-current transmission of the phase-changing rectifier of the power grid) is generally a thyristor, and the on-off state of the valve is continuously changed in the running process, so that strong nonlinearity is brought to an alternating current-direct-current hybrid system.
In order to improve the transient stability of the ac/dc hybrid power grid, a transient response mechanism of the dc power transmission system is proposed in the industry, that is, the power flow of the receiving-end power grid is controlled in advance before the ac/dc system generates large-scale power fluctuation caused by continuous commutation failure, so as to reduce the influence of power shortage caused by the continuous commutation failure of the dc system. However, the transient response mechanism depends on the advanced evaluation and early warning of the running state of the ac/dc system, and a reliable evaluation method is difficult to advance due to the complexity of the ac/dc system. How to evaluate the risk of transient instability of the dc system still is a technical problem.
Disclosure of Invention
The invention aims to solve the problem of transient stability risk assessment of an alternating current-direct current hybrid system under large disturbance, and is different from the traditional pure physical mechanism modeling method.
For the reader to better understand the technical solution of the present invention, before introducing the technical solution, the technical terms used in the present invention are first described as follows:
AC/DC control system: the system is characterized by comprising a series of controller sets including a direct current converter valve controller body and having the capacity of recording field operation data;
the direct current control system refers to a direct current system converter valve body controller and generally comprises a constant current controller, a constant voltage controller, a constant gamma angle controller, a current margin controller and αminA controller;
state variables of the direct current control system: the method mainly refers to the integrator output quantity of a related PI controller of a pole control stage of a direct current converter valve controller, and the integrator output quantity is output by an integrator and cannot be suddenly changed, so that the integrator output quantity is used as a state variable to carry out initial value iteration when numerical integration is solved; the output quantity of PI links of all controllers in the converter valve controller of the direct current system needs to be recorded in real time, and the output quantity of the PI links is the state variable of the control system;
in order to achieve the purpose, the invention specifically adopts the following technical scheme:
a transient stability risk assessment method for an alternating current-direct current power grid is characterized by comprising the following steps:
step 1: fault set for constructing AC/DC hybrid power gridThe fault concentration data includes off-line simulation dataAnd real recording data
Step 2: for the AC-DC series-parallel power grid fault set constructed in the step 1Analyzing the data, calibrating the fault capacity delta P equivalent to the alternating current fault for each fault situation, namely disturbance situationacAt the same timeRecording state variables of a DC control systemAnd the delay flip angle of the inverting side
And step 3: in the running process of the AC-DC hybrid power grid, the AC-DC protection system carries out real-time online monitoring on the running state of the AC-DC hybrid power grid, and if AC disturbance occurs, the fault capacity of the AC system is estimated by estimation
And 4, step 4: using estimated fault capacityTo AC/DC series-parallel connection electric network fault setCarrying out rapid parallel retrieval sampling to obtain N sampling values of response of the alternating current system under the fault capacity;
and 5: reading in the state variables of the DC control system recorded in step 2And the delay flip angle of the inverting sideInputting the N sampling values obtained in the step (4) into a dynamic phasor equivalent model of the direct current converter station for rapid parallel analytical calculation, and obtaining direct current responses corresponding to the sampling values of all alternating current systems under the equivalent model, namely expected responses of the direct current systems;
step 6: performing statistical analysis on the expected response of the direct current system obtained in the step 5, calibrating the number of events of the transient instability of the alternating current-direct current hybrid power grid under N sampling values, calculating the proportion of the events of the transient instability under the parallel sampling, and taking the proportion as the estimated value of the transient instability risk;
and 7: and returning to the step 2 to the step 6, repeating the steps for K times, calculating a corresponding updated risk index, namely an estimated value of the transient instability risk each time, and carrying out weighted average to obtain a final transient instability risk evaluation value of the alternating current/direct current power grid.
The invention further comprises the following preferred embodiments:
in step 1, the offline simulation data refers to TB-level operating data obtained by performing grid-type electromagnetic transient simulation on the ac/dc hybrid network, recording responses of the ac/dc system under various disturbance situations, and performing TB-level simulation.
The real wave recording data refers to real wave recording data obtained in the running process of the alternating current-direct current hybrid power grid.
In step 2, the state variable of the control system refers to the integrator output quantity of the related PI controller of the pole control stage of the DC converter valve controller.
In step 3, when the alternating current disturbance occurs to the alternating current/direct current hybrid power grid, the alternating current/direct current protection system measures and obtains a direct current power disturbance value delta PdcAnd estimating the fault capacity of the AC system based thereon
Estimation of the fault capacity of an ac system preferably by the following ac/dc power estimation formula
Where k is a scaling factor, derived from the fault set fitting, oa is the allowed residual error.
The proportion coefficient k is used for calibrating the fault capacity delta P equivalent to the alternating-current fault in each fault situation obtained in the step 2acAnd off-line simulation data in step 1And fitting to obtain.
The permissible residual oa value range is 0.03p.u. -0.06p.u.
The allowed residual oa value is 0.05p.u.
In step 4, the fault set of the AC/DC hybrid power gridIn the method, relevant recording data under all fault situations are searched, as long as the power disturbance of the alternating current system of any fault situation meets the fault capacity of the alternating current system estimated in the step 3And within the allowable residual error range, namely, taking the residual error as a fault situation required by risk assessment, wherein the wave recording data of the bus voltage of the inverter alternating-current system under the fault situation is a sampling value.
In step 4, the recorded wave recording data of the bus voltage of the inverter alternating current system under the fault situation takes 3-4 pieces of periodic wave data as a sampling value.
Preferably, the ac/dc power conversion formula is modified as follows:
then the residual error estimate of the fault capacity of the ac systemSatisfies the interval [ k delta Pdc-ò,kΔPdc+ò]In, i.e. in, the data setRelevant recording data under all fault situations are searched, as long as the alternating current system power disturbance of any fault situation meets the condition of [ K delta Pdc-ò,kΔPdc+ò]Within the scope of fault scenarios required for their use as risk assessment.
The N sampling values refer to wave recording data of the first N fault situations meeting the conditions.
Wherein the value of N is determined based on a tradeoff between risk assessment speed and risk assessment accuracy.
When the rapidity requirement of the risk assessment is greater than the requirement on the accuracy of the risk assessment, N takes a relatively small numerical value, and the value range is as follows: [500,2000].
When the accuracy requirement of the risk assessment is greater than the rapidity requirement of the risk assessment, N takes a relatively large numerical value, and the value range is as follows: [20000,80000].
When the balance between the risk assessment speed and the risk assessment accuracy is considered, the value range of N is [5000,10000 ].
In step 5, the direct current converter station dynamic phasor equivalent model is an equivalent model of a direct current system electromagnetic transient level.
In step 6, an estimate of the risk of transient destabilization is calculated by:
in the above formula, hunstableThe (phi) is a discrimination function for judging whether the AC/DC system generates transient instability, and outputs 1 when the transient instability occurs, otherwise outputs 0;is a direct current system response function based on a dynamic phasor method; x is the number ofiRefers to the ith generalized sample value vector that satisfies the sampling requirement.
Wherein the ith generalized sample value vector x satisfying the sampling requirementiIncluding state variables of the control systemContravariant side flip angleAnd recording the wave value of the alternating current bus voltage of the alternating current system.
In step 7, the value of K is 2-5. Preferably, K is 3.
Note the bookThe instability risk assessment calculated for the i-th assessment,a risk estimate calculated for the i +1 th assessment;
when i >1, there are
s.t.α+β=1,
α,β≥0
Final AC/DC power grid transient instability risk assessment value Rest=RkWherein i +1 is less than or equal to K.
WhereinThe risk assessment value calculated for the (i + 1) th evaluation (the calculation method is the calculation process from step 2 to step 6), Ri+1For the i +1 th risk assessment value updated according to the αβ rule, the intention is that the next assessment is the calculated value of the next assessmentRisk estimate R updated from previous αβ ruleiThe weighted average of (2) to prevent a certain estimation value from being too different from the rest estimation values to cause great influence on the real estimation value.
Generally, α is given by human, the simplest method is to take the value of 0.5 respectively, however, there is also a trade-off between the volatility of the iterative process of risk assessment, if β is infinitely close to 1, then according to αβ ruleUpdated i +1 th risk assessment value depends mainly on last risk assessment valueIn turn, if the risk estimation value which is updated according to the αβ rule each time has a very smooth updating process, the value of α should be as large as possible, so that the influence of each single estimation on the final estimation value is relatively limited, i.e. smooth updating of the risk estimation value updated according to the αβ rule can be realized.
Compared with the prior art, the invention has the following beneficial technical effects:
the method provided by the invention can quickly evaluate the risk of continuous commutation failure of the direct current transmission system based on the measurement information after the alternating current disturbance occurs, overcomes the problem that the running risk of the direct current transmission system is difficult to evaluate, accelerates the calculation speed under the engineering field application based on the analysis of the equivalent model and the parallel calculation of the direct current converter station, and has wide engineering application prospect.
Drawings
FIG. 1 is a schematic flow chart of the risk assessment method for transient stability of an AC/DC power grid according to the present invention;
Detailed Description
The technical scheme of the invention is further described in detail by combining the drawings and the specific embodiments in the specification.
The invention provides an AC/DC system transient stability risk assessment method based on a fault set and a DC converter station equivalent model, as shown in the attached figure 1, comprising the following steps:
step 1: construction ofFault set of AC-DC hybrid power gridThe fault concentration data includes off-line simulation dataAnd real recording data
The off-line simulation data refers to TB-level operation data obtained by performing grid-type electromagnetic transient simulation on the alternating current-direct current hybrid network, recording the response of the alternating current-direct current system under various disturbance situations, and performing TB-level simulation.
The real wave recording data refers to real wave recording data obtained in the running process of the alternating current-direct current hybrid power grid.
Step 2: for the AC-DC series-parallel power grid fault set constructed in the step 1Analyzing the data, calibrating the fault capacity delta P equivalent to the alternating current fault for each fault situation, namely disturbance situationacWhile recording the state variables of the DC control systemAnd the delay flip angle of the inverting side
The state variable of the control system refers to the output quantity of an integrator of a related PI controller of a pole control stage of the direct current converter valve controller.
And step 3: in the running process of the AC-DC hybrid power grid, the AC-DC protection system carries out real-time online monitoring on the running state of the AC-DC hybrid power grid, and if AC disturbance occurs, the fault capacity of the AC system is estimated by estimation
When alternating current disturbance occurs to the alternating current and direct current hybrid power grid, a direct current power disturbance value delta P is measured and obtained by an alternating current and direct current protection systemdcAnd estimating the fault capacity of the AC system based thereon
Estimation of the fault capacity of an ac system preferably by the following ac/dc power estimation formula
Where k is a scaling factor, derived from the fault set fitting, oa is the allowed residual error.
Wherein, the proportion coefficient k is used for calibrating the fault capacity delta P equivalent to the alternating current fault in each fault situation obtained in the step 2acAnd off-line simulation data in step 1And fitting to obtain.
The permissible residual oa value range is 0.03p.u. -0.06p.u.
And 4, step 4: using estimated fault capacityTo AC/DC series-parallel connection electric network fault setCarrying out rapid parallel retrieval sampling to obtain N sampling values of response of the alternating current system under the fault capacity;
and 3-4 cycle data are taken as a sampling value from the recorded wave recording data of the bus voltage of the inverter alternating current system under the fault situation.
Preferably, the ac/dc power conversion formula is modified as follows:
then the residual error estimate of the fault capacity of the ac systemSatisfies the interval [ k delta Pdc-ò,kΔPdc+ò]In, i.e. in, the data setRelevant recording data under all fault situations are searched, as long as the alternating current system power disturbance of any fault situation meets the condition that [ k delta P ]dc-ò,kΔPdc+ò]Within the scope of fault scenarios required for their use as risk assessment.
The N sampling values refer to wave recording data of the first N fault situations meeting the conditions.
Wherein the value of N is determined based on a tradeoff between risk assessment speed and risk assessment accuracy.
And 5: reading in the state variables of the DC control system recorded in step 2And the delay flip angle of the inverting sideInputting the N sampling values obtained in the step (4) into a dynamic phasor equivalent model of the direct current converter station for rapid parallel analytical calculation, and obtaining direct current responses corresponding to the sampling values of all alternating current systems under the equivalent model, namely expected responses of the direct current systems;
the direct current converter station dynamic phasor equivalent model is an equivalent model of direct current system electromagnetic transient level in the prior art. Referring to fig. 2, the dynamic phasor equivalent model is essentially an analytical expression of the switching function of the dc system based on the dynamic phasor method, thereby describing the dc system as a model of a voltage controlled current source. The model receives the voltages of the alternating current buses on the inversion side and the rectification side as input, and outputs an alternating current value which is injected into an alternating current system by a direct current system and has the same time length as the input alternating voltage.
Step 6: performing statistical analysis on the expected response of the direct current system obtained in the step 5, calibrating the number of events of the transient instability of the alternating current-direct current hybrid power grid under N sampling values, calculating the proportion of the events of the transient instability under the parallel sampling, and taking the proportion as the estimated value of the transient instability risk;
an estimate of the risk of transient destabilization is calculated by:
in the above formula, hunstableThe (phi) is a discrimination function for judging whether the AC/DC system generates transient instability, and outputs 1 when the transient instability occurs, otherwise outputs 0;is a direct current system response function based on a dynamic phasor method; x is the number ofiRefers to the ith generalized sample value vector that satisfies the sampling requirement.
Wherein the ith generalized sample value vector x satisfying the sampling requirementiIncluding state variables of the control systemContravariant side flip angleAnd recording the wave value of the alternating current bus voltage of the alternating current system.
And 7: and returning to the step 2 to the step 6, repeating the steps for K times, calculating a corresponding updated risk index, namely an estimated value of the transient instability risk each time, and carrying out weighted average to obtain a final transient instability risk evaluation value of the alternating current/direct current power grid.
The value of K is 2-5. Preferably, k is 3.
Note the bookThe instability risk assessment calculated for the i-th assessment,a risk estimate calculated for the i +1 th assessment;
when i >1, there are
s.t.α+β=1,
α,β≥0
Final AC/DC power grid transient instability risk assessment value Rest=RkWherein i +1 is less than or equal to K.
WhereinThe risk assessment value calculated for the (i + 1) th evaluation (the calculation method is the calculation process from step 2 to step 6), Ri+1For the i +1 th risk assessment value updated according to the αβ rule, the intention is that the next assessment is the calculated value of the next assessmentRisk estimate R updated from previous αβ ruleiThe weighted average of (2) to prevent a certain estimation value from being too different from the rest estimation values to cause great influence on the real estimation value.
Generally, α is given by human, the simplest approach is to take the value of 0.5 respectively, however, this involves a trade-off of the volatility of the iterative process of risk assessment, if β is infinitely close to 1, then the i +1 th risk assessment updated according to αβ is mainly dependent on the last risk assessmentIn turn, if the risk estimation value which is updated according to the αβ rule each time has a very smooth updating process, the value of α should be as large as possible, so that the influence of each single estimation on the final estimation value is relatively limited, i.e. smooth updating of the risk estimation value updated according to the αβ rule can be realized.
In order to better assist the reader in understanding the technical aspects of the present invention, the following examples are presented in detail.
Example 1:
a fault set and direct current converter station equivalent model-based alternating current and direct current system transient stability risk assessment method comprises the following steps:
step 1: fault set for constructing AC/DC hybrid power gridThe fault concentration data includes off-line simulation dataAnd real recording data
The off-line simulation data refers to TB-level operation data obtained by performing grid-type electromagnetic transient simulation on the alternating current-direct current hybrid network, recording the response of the alternating current-direct current system under various disturbance situations, and performing TB-level simulation.
The real wave recording data refers to real wave recording data obtained in the running process of the alternating current-direct current hybrid power grid.
Step 2: for the AC-DC series-parallel power grid fault set constructed in the step 1Data go onAnalyzing, calibrating the fault capacity delta P equivalent to the alternating current fault for each fault situation, namely disturbance situationacWhile recording the state variables of the DC control systemAnd the delay flip angle of the inverting side
The state variable of the control system refers to the output quantity of an integrator of a related PI controller of a pole control stage of the direct current converter valve controller.
And step 3: in the running process of the AC-DC hybrid power grid, the AC-DC protection system carries out real-time online monitoring on the running state of the AC-DC hybrid power grid, and if AC disturbance occurs, the fault capacity of the AC system is estimated by estimation
When alternating current disturbance occurs to the alternating current and direct current hybrid power grid, a direct current power disturbance value delta P is measured and obtained by an alternating current and direct current protection systemdcAnd estimating the fault capacity of the AC system based thereon
Estimation of the fault capacity of an ac system preferably by the following ac/dc power estimation formula
Where k is a scaling factor, derived from the fault set fitting, oa is the allowed residual error.
In general, the value of k is related to the short-circuit ratio of the dc system, and is generally [1.2,8 ]]In example 1, the receiver ac system is a very weak system that receives power injection into the primary sourceFrom the direct current system, the rapidity requirement of risk assessment is greater than the requirement on the accuracy of risk assessment, and the fitting result of k is 1.2. Wherein, the proportion coefficient k is used for calibrating the fault capacity delta P equivalent to the alternating current fault in each fault situation obtained in the step 2acAnd off-line simulation data in step 1And fitting to obtain.
In embodiment 1, the permissible residual oa takes the value 0.04p.u.
And 4, step 4: using estimated fault capacityTo AC/DC series-parallel connection electric network fault setCarrying out rapid parallel retrieval sampling to obtain N sampling values of response of the alternating current system under the fault capacity;
and 3-4 cycle data are taken as a sampling value from the recorded wave recording data of the bus voltage of the inverter alternating current system under the fault situation.
Preferably, the ac/dc power conversion formula is modified as follows:
then the residual error estimate of the fault capacity of the ac systemSatisfies the interval [ k delta Pdc-ò,kΔPdc+ò]In, i.e. in, the data setRelevant recording data under all fault situations are searched, as long as the alternating current system power disturbance of any fault situation meets the condition that [ k delta P ]dc-ò,kΔPdc+ò]Within the scope of fault scenarios required for their use as risk assessment.
The N sampling values refer to wave recording data of the first N fault situations meeting the conditions. The rapidity requirement of the risk assessment of the embodiment 1 is greater than the requirement on the accuracy of the risk assessment, and the value range of N is [500,2000], which is taken as 500.
And 5: reading in the state variables of the DC control system recorded in step 2And the delay flip angle of the inverting sideInputting the N sampling values obtained in the step (4) into a dynamic phasor equivalent model of the direct current converter station for rapid parallel analytical calculation, and obtaining direct current responses corresponding to the sampling values of all alternating current systems under the equivalent model, namely expected responses of the direct current systems;
the direct current converter station dynamic phasor equivalent model is an equivalent model of direct current system electromagnetic transient level in the prior art.
Step 6: performing statistical analysis on the expected response of the direct current system obtained in the step 5, calibrating the number of events of the transient instability of the alternating current-direct current hybrid power grid under N sampling values, calculating the proportion of the events of the transient instability under the parallel sampling, and taking the proportion as the estimated value of the transient instability risk;
an estimate of the risk of transient destabilization is calculated by:
in the above formula, hunstableThe (phi) is a discrimination function for judging whether the AC/DC system generates transient instability, and outputs 1 when the transient instability occurs, otherwise outputs 0; i (-) is an indicator function;is a direct current system response function based on a dynamic phasor method; x is the number ofiRefers to the ith generalized sample that satisfies the sampling requirementA vector of values.
Wherein the ith generalized sample value vector x satisfying the sampling requirementiIncluding state variables of the control systemContravariant side flip angleAnd recording the wave value of the alternating current bus voltage of the alternating current system.
And 7: and returning to the step 2 to the step 6, repeating the steps for K times, calculating a corresponding updated risk index, namely an estimated value of the transient instability risk each time, and carrying out weighted average to obtain a final transient instability risk evaluation value of the alternating current/direct current power grid.
And K is 3.
Note the bookThe instability risk assessment calculated for the i-th assessment,a risk estimate calculated for the i +1 th assessment;
when i >1, there are
s.t.α+β=1,
α,β≥0
Final AC/DC power grid transient instability risk assessment value Rest=RkWherein i +1 is less than or equal to 3.
The allowed residual oa value is 0.05p.u.
Example 2: a fault set and direct current converter station equivalent model-based alternating current and direct current system transient stability risk assessment method comprises the following steps:
step 1: fault set for constructing AC/DC hybrid power gridThe fault concentration data includes off-line simulation dataAnd real recording data
The off-line simulation data refers to TB-level operation data obtained by performing grid-type electromagnetic transient simulation on the alternating current-direct current hybrid network, recording the response of the alternating current-direct current system under various disturbance situations, and performing TB-level simulation.
The real wave recording data refers to real wave recording data obtained in the running process of the alternating current-direct current hybrid power grid.
Step 2: for the AC-DC series-parallel power grid fault set constructed in the step 1Analyzing the data, calibrating the fault capacity delta P equivalent to the alternating current fault for each fault situation, namely disturbance situationacWhile recording the state variables of the DC control systemAnd the delay flip angle of the inverting side
The state variable of the control system refers to the output quantity of an integrator of a related PI controller of a pole control stage of the direct current converter valve controller.
And step 3: in the running process of the AC-DC hybrid power grid, the AC-DC protection system carries out real-time online monitoring on the running state of the AC-DC hybrid power grid, and if AC disturbance occurs, the fault capacity of the AC system is estimated by estimation
When alternating current disturbance occurs to the alternating current and direct current hybrid power grid, a direct current power disturbance value delta P is measured and obtained by an alternating current and direct current protection systemdcAnd estimating the fault capacity of the AC system based thereon
Estimation of the fault capacity of an ac system preferably by the following ac/dc power estimation formula
Where k is a scaling factor, derived from the fault set fitting, oa is the allowed residual error. The receiving end communication system is a medium-intensity system, the rapidity requirement of risk assessment is the same as the accuracy requirement of risk assessment, and the fitting result of k is 4.
Wherein, the proportion coefficient k is used for calibrating the fault capacity delta P equivalent to the alternating current fault in each fault situation obtained in the step 2acAnd off-line simulation data in step 1And fitting to obtain.
In embodiment 2, the permissible residual oa takes the value 0.05 pu..
And 4, step 4: using estimated fault capacityTo AC/DC series-parallel connection electric network fault setCarrying out rapid parallel retrieval sampling to obtain N sampling values of response of the alternating current system under the fault capacity;
and 3-4 cycle data are taken as a sampling value from the recorded wave recording data of the bus voltage of the inverter alternating current system under the fault situation.
Preferably, the ac/dc power conversion formula is modified as follows:
then the residual error estimate of the fault capacity of the ac systemSatisfies the interval [ k delta Pdc-ò,kΔPdc+ò,]In, i.e. in, the data setRelevant recording data under all fault situations are searched, as long as the alternating current system power disturbance of any fault situation meets the condition that [ k delta P ]dc-ò,kΔPdc+ò,]Within the scope of fault scenarios required for their use as risk assessment.
The N sampling values refer to wave recording data of the first N fault situations meeting the conditions. Wherein the value of N is determined based on a tradeoff between risk assessment speed and risk assessment accuracy.
The rapidity requirement and the accuracy requirement of risk assessment in embodiment 2 are the same, and the value range of N is [5000,10000], which is assumed to be 5000 here.
And 5: reading in the state variables of the DC control system recorded in step 2And the delay flip angle of the inverting sideInputting the N sampling values obtained in the step (4) into a dynamic phasor equivalent model of the direct current converter station for rapid parallel analytical calculation, and obtaining direct current responses corresponding to the sampling values of all alternating current systems under the equivalent model, namely expected responses of the direct current systems;
the direct current converter station dynamic phasor equivalent model is an equivalent model of direct current system electromagnetic transient level in the prior art.
Step 6: performing statistical analysis on the expected response of the direct current system obtained in the step 5, calibrating the number of events of the transient instability of the alternating current-direct current hybrid power grid under N sampling values, calculating the proportion of the events of the transient instability under the parallel sampling, and taking the proportion as the estimated value of the transient instability risk;
an estimate of the risk of transient destabilization is calculated by:
in the above formula, hunstableThe (phi) is a discrimination function for judging whether the AC/DC system generates transient instability, and outputs 1 when the transient instability occurs, otherwise outputs 0; i (-) is an indicator function;is a direct current system response function based on a dynamic phasor method; x is the number ofiRefers to the ith generalized sample value vector that satisfies the sampling requirement.
Wherein the ith generalized sample value vector x satisfying the sampling requirementiIncluding state variables of the control systemContravariant side flip angleAnd recording the wave value of the alternating current bus voltage of the alternating current system.
And 7: and returning to the step 2 to the step 6, repeating the steps for K times, calculating a corresponding updated risk index, namely an estimated value of the transient instability risk each time, and carrying out weighted average to obtain a final transient instability risk evaluation value of the alternating current/direct current power grid.
And K is 4.
Note the bookThe instability risk assessment calculated for the i-th assessment,a risk estimate calculated for the i +1 th assessment;
when i >1, there are
s.t.α+β=1,
α,β≥0
Final AC/DC power grid transient instability risk assessment value Rest=RkWherein i +1 is less than or equal to 4.
The allowed residual oa value is 0.05p.u.
Example 3:
a fault set and direct current converter station equivalent model-based alternating current and direct current system transient stability risk assessment method comprises the following steps:
step 1: fault set for constructing AC/DC hybrid power gridThe fault concentration data includes off-line simulation dataAnd real recording data
The off-line simulation data refers to TB-level operation data obtained by performing grid-type electromagnetic transient simulation on the alternating current-direct current hybrid network, recording the response of the alternating current-direct current system under various disturbance situations, and performing TB-level simulation.
The real wave recording data refers to real wave recording data obtained in the running process of the alternating current-direct current hybrid power grid.
Step 2: for the AC-DC series-parallel power grid fault set constructed in the step 1Analyzing the data, calibrating the fault capacity delta P equivalent to the alternating current fault for each fault situation, namely disturbance situationacWhile recording the state variables of the DC control systemAnd the delay flip angle of the inverting side
The state variable of the control system refers to the output quantity of an integrator of a related PI controller of a pole control stage of the direct current converter valve controller.
And step 3: in the running process of the AC-DC hybrid power grid, the AC-DC protection system carries out real-time online monitoring on the running state of the AC-DC hybrid power grid, and if AC disturbance occurs, the fault capacity of the AC system is estimated by estimation
When alternating current disturbance occurs to the alternating current and direct current hybrid power grid, a direct current power disturbance value delta P is measured and obtained by an alternating current and direct current protection systemdcAnd estimating the fault capacity of the AC system based thereon
Estimation of the fault capacity of an ac system preferably by the following ac/dc power estimation formula
Wherein k is a proportionality coefficient consisting ofThe fault set is derived from the fitting, oa being the permissible residual. The receiving end communication system is a strong system, the requirement on the accuracy of risk assessment is far higher than the requirement on the rapidity of risk assessment, and the fitting result of k is 8. Wherein, the proportion coefficient k is used for calibrating the fault capacity delta P equivalent to the alternating current fault in each fault situation obtained in the step 2acAnd off-line simulation data in step 1And fitting to obtain.
In embodiment 3, the permissible residual oa takes the value 0.05 pu..
And 4, step 4: using estimated fault capacityTo AC/DC series-parallel connection electric network fault setCarrying out rapid parallel retrieval sampling to obtain N sampling values of response of the alternating current system under the fault capacity;
and 3-4 cycle data are taken as a sampling value from the recorded wave recording data of the bus voltage of the inverter alternating current system under the fault situation.
Preferably, the ac/dc power conversion formula is modified as follows:
then the residual error estimate of the fault capacity of the ac systemSatisfies the interval [ k delta Pdc-ò,kΔPdc+ò,]In, i.e. in, the data setRelevant recording data under all fault situations are searched, as long as the alternating current system power disturbance of any fault situation meets the condition that [ k delta P ]dc-ò,kΔPdc+ò,]Within the range ofI.e. the fault scenario required for its risk assessment.
The N sampling values refer to wave recording data of the first N fault situations meeting the conditions. Wherein the value of N is determined based on a tradeoff between risk assessment speed and risk assessment accuracy.
The requirement for rapidity of risk assessment in embodiment 3 is much lower than the requirement for accuracy of risk assessment, and the value range of N is [20000,80000], which is assumed here to be 80000.
And 5: reading in the state variables of the DC control system recorded in step 2And the delay flip angle of the inverting sideInputting the N sampling values obtained in the step (4) into a dynamic phasor equivalent model of the direct current converter station for rapid parallel analytical calculation, and obtaining direct current responses corresponding to the sampling values of all alternating current systems under the equivalent model, namely expected responses of the direct current systems;
the direct current converter station dynamic phasor equivalent model is an equivalent model of direct current system electromagnetic transient level in the prior art.
Step 6: performing statistical analysis on the expected response of the direct current system obtained in the step 5, calibrating the number of events of the transient instability of the alternating current-direct current hybrid power grid under N sampling values, calculating the proportion of the events of the transient instability under the parallel sampling, and taking the proportion as the estimated value of the transient instability risk;
an estimate of the risk of transient destabilization is calculated by:
in the above formula, hunstableThe (phi) is a discrimination function for judging whether the AC/DC system generates transient instability, and outputs 1 when the transient instability occurs, otherwise outputs 0; i (-) is an indicator function;is a direct current system response function based on a dynamic phasor method; x is the number ofiRefers to the ith generalized sample value vector that satisfies the sampling requirement.
Wherein the ith generalized sample value vector x satisfying the sampling requirementiIncluding state variables of the control systemContravariant side flip angleAnd recording the wave value of the alternating current bus voltage of the alternating current system.
And 7: and returning to the step 2 to the step 6, repeating the steps for K times, calculating a corresponding updated risk index, namely an estimated value of the transient instability risk each time, and carrying out weighted average to obtain a final transient instability risk evaluation value of the alternating current/direct current power grid.
And K is 4.
Note the bookThe instability risk assessment calculated for the i-th assessment,a risk estimate calculated for the i +1 th assessment;
when i >1, there are
s.t.α+β=1,
α,β≥0
Final AC/DC power grid transient instability risk assessment value Rest=RkWherein i +1 is less than or equal to 4.
The allowed residual oa value is 0.05p.u.
While the best mode for carrying out the invention has been described in detail and illustrated in the accompanying drawings, it is to be understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the scope of the invention should be determined by the appended claims and any changes or modifications which fall within the true spirit and scope of the invention should be construed as broadly described herein.
Claims (23)
1. A transient stability risk assessment method for an alternating current-direct current power grid is characterized by comprising the following steps:
step 1: fault set for constructing AC/DC hybrid power gridThe fault concentration data includes off-line simulation dataAnd real recording data
Step 2: for the AC-DC series-parallel power grid fault set constructed in the step 1Analyzing the data, calibrating the fault capacity delta P equivalent to the alternating current fault for each fault situation, namely disturbance situationacWhile recording the state variables of the DC control systemAnd the delay flip angle of the inverting side
And step 3: at the intersectionIn the operation process of the direct current hybrid power grid, the alternating current and direct current protection system carries out real-time online monitoring on the operation state of the alternating current and direct current hybrid power grid, and if alternating current disturbance occurs, the fault capacity of the alternating current system is estimated
And 4, step 4: using estimated fault capacityTo AC/DC series-parallel connection electric network fault setCarrying out rapid parallel retrieval sampling to obtain N sampling values of response of the alternating current system under the fault capacity;
and 5: reading in the state variables of the DC control system recorded in step 2And the delay flip angle of the inverting sideInputting the N sampling values obtained in the step (4) into a dynamic phasor equivalent model of the direct current converter station for rapid parallel analytical calculation, and obtaining direct current responses corresponding to the sampling values of all alternating current systems under the equivalent model, namely expected responses of the direct current systems;
step 6: performing statistical analysis on the expected response of the direct current system obtained in the step 5, calibrating the number of events of the transient instability of the alternating current-direct current hybrid power grid under N sampling values, calculating the proportion of the events of the transient instability under the parallel sampling, and taking the proportion as the estimated value of the transient instability risk;
and 7: and returning to the step 2 to the step 6, repeating the steps for K times, calculating a corresponding updated risk index, namely an estimated value of the transient instability risk each time, and carrying out weighted average to obtain a final transient instability risk evaluation value of the alternating current/direct current power grid.
2. The ac/dc power grid transient stability risk assessment method according to claim 1, wherein:
in step 1, the offline simulation data refers to operation data obtained by performing grid-type electromagnetic transient simulation on the ac/dc hybrid network, recording responses of the ac/dc system under various disturbance situations, and acquiring the responses.
3. The ac/dc power grid transient stability risk assessment method according to claim 2, wherein:
in step 1, the real recording data refers to real recording data obtained in the operation process of the alternating current-direct current hybrid power grid.
4. The AC/DC power grid transient stability risk assessment method according to claim 1 or 3, wherein:
in step 2, the state variable of the control system refers to the integrator output quantity of the related PI controller of the pole control stage of the DC converter valve controller.
5. The AC/DC power grid transient stability risk assessment method according to claim 4, wherein:
7. The AC/DC power grid transient stability risk assessment method according to claim 6, wherein:
8. The ac/dc power grid transient stability risk assessment method according to claim 7, wherein:
the permissible residual oa value range is 0.03p.u. -0.06p.u.
9. The ac/dc power grid transient stability risk assessment method according to claim 8, wherein:
the allowed residual oa value is 0.05p.u.
10. The ac/dc power grid transient stability risk assessment method according to claim 1, wherein:
in step 4, the fault set of the AC/DC hybrid power gridIn the method, relevant recording data under all fault situations are searched, and the fault capacity of the alternating current system is estimated in the step 3 as long as the alternating current system power disturbance of any fault situation occursAnd within the allowable residual error range, namely, taking the residual error as a fault situation required by risk assessment, wherein the wave recording data of the bus voltage of the inverter alternating-current system under the fault situation is a sampling value.
11. The ac/dc power grid transient stability risk assessment method according to claim 10, wherein:
in step 4, the recorded wave recording data of the bus voltage of the inverter alternating current system under the fault situation takes 3-4 pieces of periodic wave data as a sampling value.
12. The AC/DC power grid transient stability risk assessment method according to claim 6, wherein:
in step 4, firstly, the ac/dc power estimation formula is modified as follows:
then the residual error estimate of the fault capacity of the ac systemSatisfies the interval [ k delta Pdc-ò,kΔPdc+ò]I.e. in the data setRelevant recording data under all fault situations are searched, as long as the alternating current system power disturbance of any fault situation meets the condition that [ k delta P ]dc-ò,kΔPdc+ò,]Within the scope of fault scenarios required for their use as risk assessment.
13. The ac/dc power grid transient stability risk assessment method according to claim 12, wherein:
14. The ac/dc power grid transient stability risk assessment method according to claim 13, wherein:
wherein the value of N is determined based on a tradeoff between risk assessment speed and risk assessment accuracy.
15. The ac/dc power grid transient stability risk assessment method according to claim 14, wherein:
when the rapidity requirement of the risk assessment is greater than the requirement on the accuracy of the risk assessment, N takes a relatively small numerical value, and the value range is as follows: [500,2000].
16. The ac/dc power grid transient stability risk assessment method according to claim 14, wherein:
when the accuracy requirement of the risk assessment is greater than the rapidity requirement of the risk assessment, N takes a relatively large numerical value, and the value range is as follows: [20000,80000].
17. The ac/dc power grid transient stability risk assessment method according to claim 14, wherein: when the balance between the risk assessment speed and the risk assessment accuracy is considered, the value range of N is [5000,10000 ].
18. The ac/dc power grid transient stability risk assessment method according to claim 1, wherein:
in step 5, the direct current converter station dynamic phasor equivalent model is an equivalent model of a direct current system electromagnetic transient level.
19. The ac/dc power grid transient stability risk assessment method according to claim 1, wherein:
in step 6, an estimate R of the risk of transient instability is calculated by the following equationest:
In the above formula, hunstableThe (phi) is a discrimination function for judging whether the AC/DC system generates transient instability, and outputs 1 when the transient instability occurs, otherwise outputs 0;is a direct current system response function based on a dynamic phasor method; x is the number ofiRefers to the ith generalized sample value vector that satisfies the sampling requirement.
20. The ac/dc power grid transient stability risk assessment method according to claim 19, wherein:
21. The ac/dc power grid transient stability risk assessment method according to claim 1, wherein:
in step 7, the value of K is 2-5.
22. The ac-dc power grid transient stability risk assessment method according to claim 21, wherein:
note the bookThe instability risk assessment calculated for the i-th assessment,a risk estimate calculated for the i +1 th assessment;
when i >1, there are
s.t.α+β=1,
α,β≥0
Final AC/DC power grid transient instability risk assessment value Rest=RkWherein i +1 is less than or equal to K.
23. The ac-dc power grid transient stability risk assessment method according to claim 22, wherein:
and K is 3.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201811518505.1A CN109524982B (en) | 2018-12-12 | 2018-12-12 | AC/DC power grid transient stability risk assessment method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201811518505.1A CN109524982B (en) | 2018-12-12 | 2018-12-12 | AC/DC power grid transient stability risk assessment method |
Publications (2)
Publication Number | Publication Date |
---|---|
CN109524982A CN109524982A (en) | 2019-03-26 |
CN109524982B true CN109524982B (en) | 2020-06-16 |
Family
ID=65796148
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201811518505.1A Active CN109524982B (en) | 2018-12-12 | 2018-12-12 | AC/DC power grid transient stability risk assessment method |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN109524982B (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111064216B (en) * | 2019-12-20 | 2021-09-07 | 清华大学 | Method for quickly obtaining expected transient response of high-voltage direct-current power transmission system |
CN111162557B (en) * | 2020-01-17 | 2021-03-23 | 华北电力大学 | Sending end system transient stability margin adjusting method and system |
CN111311008B (en) * | 2020-02-21 | 2021-04-30 | 山东大学 | AC/DC large power grid dynamic security risk situation rolling prospective early warning method and system |
CN112529373B (en) * | 2020-11-26 | 2022-04-26 | 国网宁夏电力有限公司电力科学研究院 | Power grid frequency stability evaluation method under simultaneous fault of multiple loops of direct current |
CN114325213A (en) * | 2021-11-17 | 2022-04-12 | 国网江苏省电力有限公司盐城供电分公司 | Fault detection method for direct-current power transmission system |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105354675A (en) * | 2015-11-17 | 2016-02-24 | 南方电网科学研究院有限责任公司 | AC/DC power grid cascading failure analysis method based on key power transmission section recognition |
CN106712097A (en) * | 2017-02-13 | 2017-05-24 | 云南电网有限责任公司电力科学研究院 | Transient stability risk assessment method of electric power system containing large-scale wind power station |
CN106960394A (en) * | 2017-03-09 | 2017-07-18 | 国网新疆电力公司 | A kind of AC-DC hybrid power grid ability to transmit electricity appraisal procedure based on Monte Carlo |
CN108389002A (en) * | 2018-03-13 | 2018-08-10 | 国电南瑞科技股份有限公司 | A kind of multiple failure generation method based on N-1 catastrophe failure collection |
-
2018
- 2018-12-12 CN CN201811518505.1A patent/CN109524982B/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105354675A (en) * | 2015-11-17 | 2016-02-24 | 南方电网科学研究院有限责任公司 | AC/DC power grid cascading failure analysis method based on key power transmission section recognition |
CN106712097A (en) * | 2017-02-13 | 2017-05-24 | 云南电网有限责任公司电力科学研究院 | Transient stability risk assessment method of electric power system containing large-scale wind power station |
CN106960394A (en) * | 2017-03-09 | 2017-07-18 | 国网新疆电力公司 | A kind of AC-DC hybrid power grid ability to transmit electricity appraisal procedure based on Monte Carlo |
CN108389002A (en) * | 2018-03-13 | 2018-08-10 | 国电南瑞科技股份有限公司 | A kind of multiple failure generation method based on N-1 catastrophe failure collection |
Non-Patent Citations (2)
Title |
---|
Operation risk assessment for distribution system with Photovoltaic Substation connections;Y. Shang 等;《12th IET International Conference on Developments in Power System Protection (DPSP 2014)》;20140731;第1-5页 * |
基于多源信息融合的电网暂态稳定风险评估;宋墩文;《中国博士学位论文全文数据库 工程科技Ⅱ辑》;20160815(第08期);第49-137页 * |
Also Published As
Publication number | Publication date |
---|---|
CN109524982A (en) | 2019-03-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN109524982B (en) | AC/DC power grid transient stability risk assessment method | |
CN107093895B (en) | online transient state safety and stability assessment method based on automatic screening of expected fault set | |
CN104134999B (en) | Distribution network based on multi-data source measures the practical method of calculation of efficiency analysis | |
CN101425686B (en) | Electrical power system on-line safety and stability evaluation forecast failure collection adaptive selection method | |
CN105938578A (en) | Large-scale photovoltaic power station equivalent modeling method based on clustering analysis | |
CN103870703B (en) | A kind of dynamic short-circuit ratio computational methods based on Thevenin's equivalence parameter tracking | |
CN107359612B (en) | Comprehensive evaluation method for influence of power quality on power distribution network energy consumption | |
CN112069727B (en) | Intelligent transient stability evaluation system and method with high reliability for power system | |
CN105978016A (en) | Optimization control method based on optimal power flow for multi-terminal flexible direct current transmission system | |
CN109428327B (en) | Power grid key branch and leading stable mode identification method and system based on response | |
CN105098763A (en) | Transient voltage stable on-line assessment method based on WAMS and EMS | |
CN108448585A (en) | A kind of electric network swim equation solution method of linearization based on data-driven | |
CN112039108B (en) | Single-ended transient response rapid estimation model and calculation method for high-voltage direct-current power transmission system | |
CN111654392A (en) | Low-voltage distribution network topology identification method and system based on mutual information | |
CN104319760B (en) | Method and system for evaluating voltage supporting capability of multi-direct-current-fed alternating-current power grid | |
CN110783918A (en) | Linear model-based power distribution three-phase interval state estimation solving algorithm | |
CN113791351B (en) | Lithium battery life prediction method based on transfer learning and difference probability distribution | |
CN105610161B (en) | Dynamic impedance based stability characteristic estimation method of power system | |
CN114970154A (en) | Transient voltage supporting capability quantitative evaluation index construction method | |
CN109613372B (en) | Power grid fault diagnosis method based on multi-element power grid database | |
CN112100946B (en) | Inverter open-circuit fault diagnosis method and device based on fault online simulation | |
CN108233356B (en) | Consistency evaluation method and evaluation platform for photovoltaic inverter controller | |
CN113092933A (en) | LSTM-based single-phase earth fault line selection method and system | |
CN104240036B (en) | A kind of Transient Voltage Stability quantitative estimation method based on critical system equiva lent impedance | |
CN103928923B (en) | A kind of network stationary power quality method for early warning based on sensitivity analysis |
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 |