CN109256769B - Transient stability evaluation method for uncertain power system - Google Patents

Transient stability evaluation method for uncertain power system Download PDF

Info

Publication number
CN109256769B
CN109256769B CN201811135263.8A CN201811135263A CN109256769B CN 109256769 B CN109256769 B CN 109256769B CN 201811135263 A CN201811135263 A CN 201811135263A CN 109256769 B CN109256769 B CN 109256769B
Authority
CN
China
Prior art keywords
transient
power system
equation
state
state quantity
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
CN201811135263.8A
Other languages
Chinese (zh)
Other versions
CN109256769A (en
Inventor
晏永飞
刘志坚
孙应毕
王旭辉
徐慧
周于尧
王一菲
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.)
Kunming University of Science and Technology
Original Assignee
Kunming University of Science and Technology
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 Kunming University of Science and Technology filed Critical Kunming University of Science and Technology
Priority to CN201811135263.8A priority Critical patent/CN109256769B/en
Publication of CN109256769A publication Critical patent/CN109256769A/en
Application granted granted Critical
Publication of CN109256769B publication Critical patent/CN109256769B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • 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
    • H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention relates to an uncertain power system transient stability assessment method, and belongs to the field of power system stability. The method of the invention comprises the following steps: firstly, inputting basic structure data of a power system to obtain an electromechanical transient equation describing a generator, and further obtaining a state equation of a vector form of the electromechanical transient equation; determining the disturbance amount lambda of the system; and establishing an uncertain power system transient stability evaluation model introducing uncertain variables, and calculating related response coefficients by adopting an interval Taylor expansion method to obtain upper and lower limits of the state quantity x in the transient process of the power system. The simulation of a single-machine infinite system shows that the method provided by the invention can effectively evaluate the transient stability of an uncertain power system.

Description

Transient stability evaluation method for uncertain power system
Technical Field
The invention relates to an uncertain power system transient stability assessment method, and belongs to the field of power system stability.
Background
Modern power systems are developed into large-scale regional interconnected power grids, and the development can bring great economy and make the transient stability problem more complicated. Transient instability remains one of the biggest threats faced by modern power systems. Effective real-time transient stability prediction and emergency control are of great importance. The traditional transient stability control strategy mainly adopts a control method of 'making a strategy table off line and matching in real time'. And the system model and the parameters have some deviation, thereby influencing the accuracy of the calculation result. At present, a common transient stability analysis method is time domain simulation, the time domain simulation method can be used for testing the stability of a device in the later stage of design and is considered as a standard for testing other stability analysis methods, but the simulation method has the defects of large calculation amount, long simulation time, incapability of simulating all running states and the like, and therefore quantitative information of the stability degree of a system cannot be obtained. The other main transient stability analysis method is a direct method based on a modern differential power system, and the method can deeply research the mechanism of the transient stability of the system and has extremely high academic value. The direct method does not need to integrate the system after the fault, and directly judges the transient stability of the system by comparing the transient energy of the system at the fault clearing moment with the critical energy. And a transient stability analysis method using an artificial intelligence algorithm as a guide, wherein the method has the defect that if an error exists between online data and preset data, the result is not ideal.
With the wide access of power electronics, new energy and the like, the operation of a power system has great uncertainty, so that the traditional power system analysis method is not suitable any more. Aiming at the influence of uncertain input quantity and disturbance variable which often occur in a power system on the transient stability of the power system, the system needs to capture the uncertain input quantity and analyze the influence of the uncertain input quantity on the power system, and the uncertain power system transient evaluation method based on Taylor series expansion is provided.
Disclosure of Invention
In order to solve the existing defects, the invention provides an uncertain power system transient stability evaluation method.
The technical scheme of the invention is as follows: firstly, inputting basic structure data of a power system to obtain an electromechanical transient equation describing a generator and further obtain a state equation of a mathematical expression of the electromechanical transient equation; establishing an uncertainty electric power system transient stability evaluation model based on an interval Taylor series; establishing the disturbance quantity of the system variable; and calculating related response coefficients to obtain the upper and lower limits of the characteristic quantity in the transient process of the power system. The simulation of a single-machine infinite system shows that the method provided by the invention can effectively evaluate the transient stability of an uncertain power system.
An uncertainty electric power system transient stability evaluation method comprises the following steps:
step 1, establishing an electromechanical transient equation of a generator, and further obtaining an electromechanical transient state equation in a vector form;
step 2, determining the disturbance amount lambda of the system;
step 3, establishing an electromechanical transient state equation introducing a disturbance amount lambda;
step 4, calculating related response coefficients by adopting an interval Taylor expansion method to obtain upper and lower limits of the state quantity x in the transient process of the power system: min (max) x (t, λ) (1)
Wherein x is a state quantity of the system; t is time; λ is the disturbance amount of the state quantity x.
The specific process of the step 1 is as follows:
the following electromechanical transient equations of the generator are established:
Figure GDA0003044684330000021
wherein, deltaiIs the power angle, ω, of the ith generatoriIs the angular velocity of the ith generator; omega0Is the relative angular velocity; diIs the damping coefficient of the ith generator; pmiAnd PeiMechanical and electromagnetic power, M, of the ith generator, respectivelyiIs the mechanical power moment of inertia of the ith generator;
obtaining an electromechanical transient state equation in a vector form according to the formula:
Figure GDA0003044684330000022
wherein x is [ δ, ω ═ o]T；δ＝[δ1,...δi,...,δm]；ω＝[ω1,...ωi,...,ωm]And m is the total number of generators.
The specific process of the step 3 is as follows:
disturbance amount of input system:
λ＝[λ1,...λj,...,λn]T(4)
wherein the state quantity x varies with time t, λ1，…λj，…λnN is the number of disturbance amounts corresponding to the state amounts at each time,
establishing an electromechanical transient state equation under the condition of introducing disturbance quantity:
Figure GDA0003044684330000023
the specific process of the step 4 is as follows:
establishing a state equation of a first derivative of the state quantity x containing the uncertainty under the interval Taylor series expansion:
Figure GDA0003044684330000031
establishing a state equation of the state quantity x containing uncertainty under interval Taylor series expansion:
Figure GDA0003044684330000032
further derivation of the above equation:
Figure GDA0003044684330000033
the synthesis is as follows:
Figure GDA0003044684330000034
the corresponding terms in this equation are equal:
Figure GDA0003044684330000035
accordingly, the upper and lower limits of the state quantity x of the system changing along with the time t in the dynamic response process are obtained, wherein xcIs the state quantity, lambda, of the system in normal operationcIs corresponding to xcThe amount of disturbance of.
The invention has the beneficial effects that:
1) a novel uncertainty power system transient stability assessment method based on interval Taylor series expansion is provided, and the method can solve the problems caused by intermittent renewable energy sources and measurement errors.
2) The method is simple, has high prediction precision, can be used for early warning of transient instability of the system, further improves the timeliness of instability judgment, and reduces the cost paid by subsequent control measures as far as possible.
Drawings
FIG. 1 is a diagram of a stand-alone infinity system and its basic configuration data;
fig. 2 introduces uncertainty in the upper and lower limits of the power angle of the generator.
Detailed Description
The invention is further described with reference to the following figures and specific examples.
Example 1: an uncertain electric power system transient stability evaluation method comprises the following specific steps:
step 1, establishing an electromechanical transient equation of a generator, and further obtaining an electromechanical transient state equation in a vector form;
step 2, determining the disturbance amount lambda of the system;
step 3, establishing an electromechanical transient state equation introducing a disturbance amount lambda;
step 4, calculating related response coefficients by adopting an interval Taylor expansion method to obtain upper and lower limits of the state quantity x in the transient process of the power system: min (max) x (t, λ) (1)
Wherein x is a state quantity of the system; t is time; λ is the disturbance amount of the state quantity x.
The specific process of the step 1 is as follows:
the following electromechanical transient equations of the generator are established:
Figure GDA0003044684330000041
wherein, deltaiIs the power angle, ω, of the ith generatoriIs the angular velocity of the ith generator; omega0Is the relative angular velocity; diIs the damping coefficient of the ith generator; pmiAnd PeiMechanical and electromagnetic power, M, of the ith generator, respectivelyiIs the mechanical power moment of inertia of the ith generator;
obtaining an electromechanical transient state equation in a vector form according to the formula:
Figure GDA0003044684330000042
wherein x is [ δ, ω ═ o]T；δ＝[δ1,...δi,...,δm]；ω＝[ω1,...ωi,...,ωm]And m is the total number of generators.
The specific process of the step 3 is as follows:
disturbance amount of input system:
λ＝[λ1,...λj,...,λn]T(4)
wherein the state quantity x varies with time t, λ1，…λj，…λnN is the number of disturbance amounts corresponding to the state amounts at each time,
establishing an electromechanical transient state equation under the condition of introducing disturbance quantity:
Figure GDA0003044684330000043
the specific process of the step 4 is as follows:
establishing a state equation of a first derivative of the state quantity x containing the uncertainty under the interval Taylor series expansion:
Figure GDA0003044684330000051
establishing a state equation of the state quantity x containing uncertainty under interval Taylor series expansion:
Figure GDA0003044684330000052
further derivation of the above equation:
Figure GDA0003044684330000053
the synthesis is as follows:
Figure GDA0003044684330000054
the corresponding terms in this equation are equal:
Figure GDA0003044684330000055
accordingly, the upper and lower limits of the state quantity x of the system changing along with the time t in the dynamic response process are obtained, wherein xcIs the state quantity, lambda, of the system in normal operationcIs corresponding to xcThe amount of disturbance of.
Example 2: as shown in fig. 1-2, to verify the phase trajectory and transient energy based stability identification method presented herein, a verification was performed in a stand-alone infinity system using MATLAB software. The basic parameters of the system are as follows:
and selecting a reference value, wherein SB is 250MV, A, UB (220) is 209 kV.
Figure GDA0003044684330000056
Figure GDA0003044684330000057
Figure GDA0003044684330000058
Figure GDA0003044684330000059
Figure GDA0003044684330000061
Figure GDA0003044684330000062
E'＝1.5164
δ0＝27.75°
Where SB is the reference power of the system, UB is the reference voltage of the system,
Figure GDA0003044684330000063
is the equivalent reactance, x, of the generator stator2Is a negative sequence reactance, xL1、xL2Is the reactance per unit value, x, of line 1 and line 2T1、xT2Is the reactance per unit value, T, of the transformer 1 and the transformer 2 respectivelyJIs a constant of time, and is,
Figure GDA0003044684330000064
is a transient potential, δ0Is a power angle value.
Step S1, describing the state equation of the mathematical expression of the transient process of the generator
Figure GDA0003044684330000065
And step S2, setting the disturbance parameter of the system as the fluctuation of the mechanical power of +/-5%.
Step S3, establishing a state equation of a mathematical expression of the transient process of the generator under the condition of introducing uncertain variables;
Figure GDA0003044684330000066
step S4, obtaining the time-varying upper and lower limits of the system description system characteristic quantity, which is shown in fig. 2.
Fig. 2 shows a power angle stability curve of a single infinite system and upper and lower boundaries of dynamic response when mechanical power fluctuates by ± 5%, it can be seen that the power angle curve during stable operation of the system is within the upper and lower boundary curves of dynamic response, when the mechanical power changes, the change curve of the power angle with time slightly changes, the operation of the power system is affected by numerous uncertainty factors, and for these uncertainties, the transient stability evaluation method of the power system based on interval taylor expansion can accurately determine the transient stability of the power system.
While the present invention has been described in detail with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.

Claims (3)

1. An uncertain electric power system transient stability assessment method is characterized by comprising the following steps: the method comprises the following steps:
step 1, establishing an electromechanical transient equation of a generator, and further obtaining an electromechanical transient state equation in a vector form;
step 2, determining the disturbance amount lambda of the system;
step 3, establishing an electromechanical transient state equation introducing a disturbance amount lambda;
step 4, calculating related response coefficients by adopting an interval Taylor expansion method to obtain upper and lower limits of the state quantity x in the transient process of the power system: min (max) x (t, λ), x being the state quantity of the system; t is time; λ is the disturbance amount of the state quantity x;
the specific process of the step 4 is as follows:
establishing a state equation of a first derivative of the state quantity x containing the uncertainty under the interval Taylor series expansion:
Figure FDA0003044684320000011
establishing a state equation of the state quantity x containing uncertainty under interval Taylor series expansion:
Figure FDA0003044684320000012
further derivation of the above equation:
Figure FDA0003044684320000013
the synthesis is as follows:
Figure FDA0003044684320000014
the corresponding terms in this equation are equal:
Figure FDA0003044684320000015
accordingly, the upper and lower limits of the state quantity x of the system changing along with the time t in the dynamic response process are obtained, wherein xcIs the state quantity, lambda, of the system in normal operationcIs corresponding to xcThe amount of disturbance of.
2. The uncertainty power system transient stability assessment method of claim 1, characterized by: the specific process of the step 1 is as follows:
the following electromechanical transient equations of the generator are established:
Figure FDA0003044684320000021
wherein, deltaiIs the power angle, ω, of the ith generatoriIs the angular velocity of the ith generator; omega0Is the relative angular velocity; diIs the damping coefficient of the ith generator; pmiAnd PeiMechanical and electromagnetic power, M, of the ith generator, respectivelyiIs the mechanical power moment of inertia of the ith generator;
obtaining an electromechanical transient state equation in a vector form according to the formula:
Figure FDA0003044684320000022
wherein x is [ δ, ω ═ o]T；δ＝[δ1,...δi,...,δm]；ω＝[ω1,...ωi,...,ωm]And m is the total number of generators.
3. The uncertainty electric power system transient stability evaluation method of claim 1, characterized by: the specific process of the step 3 is as follows:
disturbance amount of input system:
λ＝[λ1,...λj,...,λn]T
wherein the state quantity x varies with time t, λ1，…λj，…λnN is the number of disturbance amounts corresponding to the state amounts at each time,
establishing an electromechanical transient state equation under the condition of introducing disturbance quantity:
Figure FDA0003044684320000023
CN201811135263.8A 2018-09-28 2018-09-28 Transient stability evaluation method for uncertain power system Active CN109256769B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201811135263.8A CN109256769B (en) 2018-09-28 2018-09-28 Transient stability evaluation method for uncertain power system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811135263.8A CN109256769B (en) 2018-09-28 2018-09-28 Transient stability evaluation method for uncertain power system

Publications (2)

Publication Number Publication Date
CN109256769A CN109256769A (en) 2019-01-22
CN109256769B true CN109256769B (en) 2021-08-20

Family

ID=65047995

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811135263.8A Active CN109256769B (en) 2018-09-28 2018-09-28 Transient stability evaluation method for uncertain power system

Country Status (1)

Country Link
CN (1) CN109256769B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009120190A1 (en) * 2008-03-26 2009-10-01 The Tokyo Electric Power Company, Incorporated Stable equilibrium point (sep) calculation apparatus of power system
CN102915471A (en) * 2012-09-26 2013-02-06 中国电力科学研究院 Wind power disturbance online safety precaution method
CN104158191A (en) * 2014-09-09 2014-11-19 武汉大学 Dispersed coordination control method for stable running of multi-machine power system
CN104217090A (en) * 2013-06-04 2014-12-17 刘光晔 Method for analyzing and calculating voltage stabilization critical point of electric power system through Taylor series
CN105305425A (en) * 2015-10-20 2016-02-03 国家电网公司 UPFC buffeting control method of additional interference observer

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009120190A1 (en) * 2008-03-26 2009-10-01 The Tokyo Electric Power Company, Incorporated Stable equilibrium point (sep) calculation apparatus of power system
CN102915471A (en) * 2012-09-26 2013-02-06 中国电力科学研究院 Wind power disturbance online safety precaution method
CN104217090A (en) * 2013-06-04 2014-12-17 刘光晔 Method for analyzing and calculating voltage stabilization critical point of electric power system through Taylor series
CN104158191A (en) * 2014-09-09 2014-11-19 武汉大学 Dispersed coordination control method for stable running of multi-machine power system
CN105305425A (en) * 2015-10-20 2016-02-03 国家电网公司 UPFC buffeting control method of additional interference observer

Also Published As

Publication number Publication date
CN109256769A (en) 2019-01-22

Similar Documents

Publication Publication Date Title
US20210042452A1 (en) Generator dynamic model parameter estimation and tuning using online data and subspace state space model
CN106526384B (en) A kind of oscillation source localization method for large-scale electrical power system
CN110119570B (en) Actually measured data driven wind farm model parameter checking method
US10234508B1 (en) Dynamic parameter estimation of generators
CN109284933B (en) Electronic transformer state evaluation system and method based on mathematical statistics
Zhang et al. Measurement-based power system dynamic model reductions
CN111046327A (en) Prony analysis method suitable for low-frequency oscillation and subsynchronous oscillation identification
CN102364490B (en) Automatic synchronization recognition method based on hierarchical analyzing model
CN111680823A (en) Wind direction information prediction method and system
CN105425611A (en) Hydraulic generator set excitation system parameter identification method
CN107958120B (en) System Thevenin equivalent parameter calculation method based on power series expansion
KR100946278B1 (en) Modeling and parameter test method for wind farm
CN109883596A (en) A kind of Suo Li automation real-time resolving method based on Spectrum Method
CN109256769B (en) Transient stability evaluation method for uncertain power system
CN110474323B (en) Method for measuring inertia time constant of power system
CN103279030A (en) Bayesian framework-based dynamic soft measurement modeling method and device
CN110098610B (en) Real-time identification method and system for oscillation leading mode of power system under fault disturbance
Papadopoulos et al. Measurement based method for online characterization of generator dynamic behaviour in systems with renewable generation
CN110943473A (en) Generator coherence identification method based on wide area measurement system and clustering theory
Dudzik et al. Optimal dynamic error formula for charge output accelerometer obtained by the neural network
Ranjbar et al. Determining wide area damping control signal (WADCS) based on C5. 0 classifier
CN109240085A (en) Non-Gaussian filtering dynamic data rectification and system control performance optimization method
Liu et al. A novel fast transient stability prediction method based on pmu
CN113408076A (en) Small sample mechanical residual life prediction method based on support vector machine model
CN109217336B (en) On-line identification method for damping coefficient of synchronous generator based on partition modeling

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