CN106130039A - The leading instability mode recognition method of power system and system - Google Patents

Abstract

The present invention relates to leading instability mode recognition method and the system of a kind of power system, described method includes: determined the interconnection at place, disturbed rear system oscillation center by wide area measurement system；The dynamic feature information of described interconnection is extracted from metric data；The first component and the second component of described interconnection sending end complex power variable quantity is calculated according to described dynamic feature information；The identification parameter of leading Failure Model is calculated according to described first component and second component；The leading Failure Model of system when judging that transient state merit angle unstability and transient voltage unstable phenomenon occur simultaneously based on described identification parameter.The present invention is in the interconnection of oscillation center by wide area measurement information determining system after disturbed, sending end active power based on interconnection and reactive power characteristic, calculate leading Failure Model identification parameter in real time to judge as leading Failure Model criterion, determine the leading Failure Model of power system.The leading Failure Model of power system can be accurately identified, provide decision-making foundation accurately for follow-up Transient Stability Control.

Description

The leading instability mode recognition method of power system and system

Technical field

The present invention relates to technical field of electric power, particularly relate to a kind of power system leading instability mode recognition method and System.

Background technology

Along with the development of extensive AC-DC interconnecting power network, the extensive access of the new forms of energy such as wind energy, solar energy, Novel electric The extensive application of power electronic installation, the transient stability characteristic of electrical network becomes increasingly complex.For this extensive alternating current-direct current complexity electricity Net, in the transient process after power system is disturbed, transient state merit angle unstability and transient voltage unstable phenomenon often weave in, one In the case of as, a kind of Failure Model occupies leading position, determines that Transient Stability Control is had by the Failure Model occupying leading position Significance.

Wide area measurement system is the most perfect in recent years, promote transient stability analysis with control towards " Real-time Decision, in real time Control " direction develop, gradually formed electrical power system wide-area security and stability control system based on real measured data.To based on extensively For the real-time transient stability analysis of territory measurement information and control, carry out leading Failure Model identification in real time and be particularly important, This is because for transient stability analysis method based on WAMS information, be different from time-domain-simulation method, when can only obtain current The disturbed trace information of system under between, it is impossible to being analyzed the disturbed situation of overall process, simultaneous computer is also difficult to abundant profit By abundant artificial experience.

Owing to for a long time Transient angle stability problem and Enhancement of Transient Voltage Stability Study on Problems being lacked relatedness, difficult To propose the leading Failure Model identifying schemes to power system, proposed INSTABILITY CRITERION is caused the most not have exclusiveness, When i.e. transient state merit angle INSTABILITY CRITERION is triggered, it is not meant to that transient voltage unstable phenomenon does not occur；In like manner transient voltage loses When steady criterion is triggered, it is not meant to that transient state merit angle unstable phenomenon does not occur, so that INSTABILITY CRITERION cannot be follow-up Transient Stability Control provides decision-making foundation accurately.

Summary of the invention

Based on this, it is necessary to for above-mentioned technical problem, it is provided that the leading instability mode recognition method of a kind of power system And system, accurately identify the leading Failure Model of power system, improve the accuracy of Transient Stability Control.

A kind of leading instability mode recognition method of power system, including:

The interconnection at place, disturbed rear system oscillation center is determined by wide area measurement system；

The dynamic feature information of described interconnection, wherein, described dynamic feature information sending end electricity is extracted from metric data Press phase angle and amplitude and the voltage phase angle of receiving end and amplitude；

The first component of described interconnection sending end complex power variable quantity and second point is calculated according to described dynamic feature information Amount；Wherein, described first component is the component relevant with the busbar voltage phase angle difference variable quantity of sending end, receiving end, and second component is The component relevant to the busbar voltage amplitude variable quantity of sending end, receiving end；

The identification parameter I of leading Failure Model is calculated according to described first component and second component,In formula, Δ S_δIt is the first component, Δ S_vFor second component, i represents data sampling instants；

The leading Failure Model of power system is judged based on described identification parameter.

A kind of leading Failure Model identification system of power system, including:

Vibration interconnection identification module, for determining the connection at place, disturbed rear system oscillation center by wide area measurement system Winding thread；

Characteristic information extracting module, for extracting the dynamic feature information of described interconnection, wherein, institute from metric data State dynamic feature information sending end voltage phase angle and amplitude and the voltage phase angle of receiving end and amplitude；

Component computing module, for calculating described interconnection sending end complex power variable quantity according to described dynamic feature information First component and second component；Wherein, described first component is relevant with the busbar voltage phase angle difference variable quantity of sending end, receiving end Component, second component is the component relevant to the busbar voltage amplitude variable quantity of sending end, receiving end；

Parameter calculating module, for calculating the identification parameter of leading Failure Model according to described first component and second component I,In formula, Δ S_δIt is the first component, Δ S_vFor second component, i represents data sampling instants；

Based on described identification parameter, pattern recognition module, for judging that transient state merit angle unstability and transient voltage unstable phenomenon are same The leading Failure Model of system during Shi Fasheng.

The leading instability mode recognition method of above-mentioned power system and system, disturbed by wide area measurement information determining system After be in the interconnection of oscillation center, sending end active power based on interconnection and reactive power characteristic, calculate leading mistake in real time Steady pattern recognition parameter judges as leading Failure Model criterion, determines the leading Failure Model of power system.Can be accurate Really identify the leading Failure Model of power system, provide decision-making foundation accurately for follow-up Transient Stability Control.

Accompanying drawing explanation

Fig. 1 is the leading instability mode recognition method flow chart of the power system of an embodiment；

Fig. 2 send receiving-end system schematic diagram；

Fig. 3 equivalence unit list load system figure；

The system schematic of Fig. 4 stability analysis；

Fig. 5 Failure Model relation schematic diagram；

Fig. 6 is 3 machine 10 node system schematic diagrams；

Fig. 7 the whole network generator's power and angle curve synoptic diagram；

Voltage curve schematic diagram near Fig. 8 oscillation center；

Fig. 9 is the leading Failure Model identification system structure schematic diagram of the power system of an embodiment.

Detailed description of the invention

Illustrate leading instability mode recognition method and the embodiment of system of the power system of the present invention below in conjunction with the accompanying drawings.

With reference to shown in Fig. 1, Fig. 1 is the leading instability mode recognition method flow chart of the power system of an embodiment, including:

Step S101, determines the interconnection at place, disturbed rear system oscillation center by wide area measurement system.

In this step, after power system is disturbed, measured by wide area measurement system, determine shaking of disturbance Swing center, determine the interconnection being in oscillation center.

Wide area measurement system can be begun through after disturbance to measure, determine that system is disturbed by wide area measurement system The interconnection at rear oscillation center place, i.e. determines the oscillation center of system according to measurement information, determines the connection being in oscillation center Winding thread.

Step S102, extracts the dynamic feature information of described interconnection from metric data, and wherein, described behavioral characteristics is believed Breath sending end voltage, phase angle and amplitude and the voltage of receiving end, phase angle and amplitude.

In this step, from the metric data of wide area measurement system magnanimity, extract the dynamic of oscillation center place interconnection State characteristic information, the sampling period of described dynamic feature information can be with the PMU (Phasor in described wide area measurement system Measurement Unit, synchronous phasor measurement system) sampling period of measuring unit is identical.

The dynamic feature information of oscillation center place interconnection include interconnection the most in the same time send receiving end voltage magnitude and Phase angle, wherein, after disturbance, the sending end voltage magnitude in the i-th moment of oscillation center is U_AI (), sending end voltage phase angle is δ_A(i), receiving end Voltage magnitude is U_BI (), receiving end voltage phase angle is δ_BI (), send, receiving end phase difference of voltage is δ (i)=δ_A(i)-δ_B(i), circuit Resistance is R_∑, reactance is X_∑。

Step S103, calculates the first component of described interconnection sending end complex power variable quantity according to described dynamic feature information And second component；Wherein, described first component is the component relevant with the busbar voltage phase angle difference variable quantity of sending end, receiving end, the Two components are the components relevant to the busbar voltage amplitude variable quantity of sending end, receiving end；

For the first component and second component, can be expressed as follows:

${\mathrm{\ΔS}}_{\mathrm{\δ}}\left(i\right)=\[\frac{U_A\left(i\right)U_B\left(i\right)}{\left|Z\right|}cos\left(\mathrm{\δ}\right(i)-a)+j\frac{U_A\left(i\right)U_B\left(i\right)}{\left|Z\right|}sin\left(\mathrm{\δ}\right(i)-a)\]\×\mathrm{\Δ}\mathrm{\δ}\left(i\right)$

$\begin{array}{c}{\mathrm{\ΔS}}_v\left(i\right)=\{\[\frac{2U_A\left(i\right)}{\left|Z\right|}\sin a+\frac{U_B\left(i\right)}{\left|Z\right|}\sin \left(\mathrm{\δ}\right(i)-a)\]+j\[\frac{2U_A\left(i\right)}{\left|Z\right|}\cos a-\frac{U_B\left(i\right)}{\left|Z\right|}\cos \left(\mathrm{\δ}\right(i)-a)\]\}\×{\mathrm{\ΔU}}_A\left(i\right)\\ +\[\frac{U_A\left(i\right)}{\left|Z\right|}\sin \left(\mathrm{\δ}\right(i)-a)-j\frac{U_A\left(i\right)}{\left|Z\right|}\cos \left(\mathrm{\δ}\right(i)-a)\]\×{\mathrm{\ΔU}}_B\left(i\right)\end{array}$

In formula, Z=R_∑+jX_∑=| Z | ∠ arctg (X_∑/R_∑), α=pi/2-arctg (X_∑/R_∑), Δ δ (i)=δ (i)-δ (i-1), Δ U_A(i)=U_A(i)-U_A(i-1), Δ U_B(i)=U_B(i)-U_B(i-1)；Wherein, the i-th moment of oscillation center sending end Voltage magnitude is U_AI (), sending end voltage phase angle is δ_AI (), receiving end voltage magnitude is U_BI (), receiving end voltage phase angle is δ_BI (), send End, the phase difference of voltage of receiving end are δ (i)=δ_A(i)-δ_BI (), the line resistance of interconnection is R_∑, the line reactance of interconnection is X_∑。

In one embodiment, the complex power variable quantity of the sending end calculating described interconnection in this step can be such that

First, according to oscillation center place interconnection and the direction of tide of reality, power system is equivalent to one and send End, the interacted system model that receiving end is clear and definite；I.e. according to oscillation center place interconnection and the direction of tide of reality, can be by system Be equivalent to a sending end, interacted system model that receiving end is clear and definite.

Then according to described interacted system model sending end, the external characteristics of receiving-end system, obtain corresponding equivalent unit list and bear G system；I.e. according to sending end, the external characteristics of receiving-end system, available corresponding equivalent unit list load system, as shown in Figure 2. The sending end power expression of interconnection is:

$P=\frac{U_A^2}{\left|Z\right|}\sin a+\frac{U_A{U}_B}{\left|Z\right|}sin(\mathrm{\δ}-a)---\left(1\right)$

$Q=\frac{U_A^2}{\left|Z\right|}\cos a-\frac{U_A{U}_B}{\left|Z\right|}cos(\mathrm{\δ}-a)---\left(2\right)$

In formula, line impedance Z=R of interconnection_∑+jX_∑=Z ∠ arctg (X_∑/R_∑)；Phase angle difference is δ=δ_A-δ_B；α=π/ 2-arctg(X_∑/R_∑)。

Calculate again under the dynamic situation of change ignoring line parameter circuit value, oscillation center place interconnection sending end in transient process The variable quantity of complex power, concrete, ignore the dynamic change of line parameter circuit value, then in transient process, oscillation center place interconnection send The total differential of end complex power is:

$dp=\frac{U_A{U}_B}{\left|Z\right|}cos(\mathrm{\δ}-a)d\mathrm{\δ}+\[\frac{2U_A}{\left|Z\right|}\sin a+\frac{U_B}{\left|Z\right|}sin(\mathrm{\δ}-a)\]{\mathrm{dU}}_A+\frac{U_A}{\left|Z\right|}sin(\mathrm{\δ}-a){\mathrm{dU}}_B---\left(3\right)$

$dQ=\frac{U_A{U}_B}{\left|Z\right|}sin(\mathrm{\δ}-a)d\mathrm{\δ}+\[\frac{2U_A}{\left|Z\right|}\cos a-\frac{U_B}{\left|Z\right|}cos(\mathrm{\δ}-a)\]{\mathrm{dU}}_A-\frac{U_A}{\left|Z\right|}cos(\mathrm{\δ}-a){\mathrm{dU}}_B---\left(4\right)$

The complex power of consideration system sending end is expressed as:

S=P+jQ (5)

Then

$\begin{array}{c}dS=\[\frac{U_A{U}_B}{\left|Z\right|}cos(\mathrm{\δ}-a)+j\frac{U_A{U}_B}{\left|Z\right|}sin(\mathrm{\δ}-a)\]d\mathrm{\δ}+\{\[\frac{2U_A}{\left|Z\right|}\sin a+\frac{U_B}{\left|Z\right|}sin(\mathrm{\δ}-a)\]\\ +j\[\frac{2U_A}{\left|Z\right|}\cos a-\frac{U_B}{\left|Z\right|}\cos (\mathrm{\δ}-a)\]\}{\mathrm{dU}}_A+\[\frac{U_A}{\left|Z\right|}\sin (\mathrm{\δ}-a)-j\frac{U_A}{\left|Z\right|}\cos (\mathrm{\δ}-a)\]{\mathrm{dU}}_B\end{array}---\left(6\right)$

Difference replaces differential to have:

$\begin{array}{c}\mathrm{\Δ}S=\[\frac{U_A{U}_B}{\left|Z\right|}\cos (\mathrm{\δ}-a)+j\frac{U_A{U}_B}{\left|Z\right|}\sin (\mathrm{\δ}-a)\]\mathrm{\Δ}\mathrm{\δ}+\{\[\frac{2U_A}{\left|Z\right|}\sin a+\frac{U_B}{\left|Z\right|}\sin (\mathrm{\δ}-a)\]\\ +j\[\frac{2U_A}{\left|Z\right|}\cos a-\frac{U_B}{\left|Z\right|}\cos (\mathrm{\δ}-a)\]\}{\mathrm{\ΔU}}_A+\[\frac{U_A}{\left|Z\right|}\sin (\mathrm{\δ}-a)-j\frac{U_A}{\left|Z\right|}\cos (\mathrm{\δ}-a)\]{\mathrm{\ΔU}}_B\end{array}---\left(7\right)$

Calculate the first component and the second component of interconnection sending end complex power variable quantity, i.e. calculate Δ S_δWith Δ S_v。

From formula (7), the complex power variable quantity of power system sending end is represented by:

${\mathrm{\ΔS}}_{\mathrm{\δ}}=\[\frac{U_A{U}_B}{\left|Z\right|}\cos (\mathrm{\δ}-a)+j\frac{U_A{U}_B}{\left|Z\right|}\sin (\mathrm{\δ}-a)\]\mathrm{\Δ}({\mathrm{\δ}}_A-{\mathrm{\δ}}_B)---\left(8\right)$

${\mathrm{\ΔS}}_v=\{\[\frac{2U_A}{\left|Z\right|}\sin a+\frac{U_B}{\left|Z\right|}\sin (\mathrm{\δ}-a)\]+j\[\frac{2U_A}{\left|Z\right|}\cos a-\frac{U_B}{\left|Z\right|}\cos (\mathrm{\δ}-a)\]\}{\mathrm{\ΔU}}_A+\[\frac{U_A}{\left|Z\right|}\sin (\mathrm{\δ}-a)-j\frac{U_A}{\left|Z\right|}\cos (\mathrm{\δ}-a)\]{\mathrm{\ΔU}}_B---\left(9\right)$

Technique scheme, changes conventional decoupling mode, and existing research is generally by active power/merit angle and idle Power/voltage decoupling is studied, although this decoupling mode reduces the complexity of Stability Analysis, but unfavorable Unified Analysis in merit angle problem Yu voltage problem.

In transient process after disturbance, Δ S reflects the change of power transmission network running status, has both comprised active power Change, also comprises the change of reactive power, and technique scheme, by Δ S_δWith Δ S_vDominate system variable as a pair to grind Study carefully transient state merit angle unstability and the dominance of transient voltage unstability, can be united in active power/merit angle and reactive power/voltage It is analyzed, it is thus possible to comprehensively reflect the transient stability problem of power system.

Step S104, calculates the identification parameter of leading Failure Model according to described first component and second component.

In this step, according to Δ S_δWith Δ S_vCalculate leading Failure Model identification parameter I, from formula (8)～(9), Δ S_δWith Δ S_vIt is a pair complex variable, takes its modulus value as leading system variable, it may be assumed that

$\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\right|=\frac{U_A{U}_B}{\left|Z\right|}\left|\mathrm{\Δ}({\mathrm{\δ}}_A-{\mathrm{\δ}}_B)\right|---\left(10\right)$

$\left|{\mathrm{\ΔS}}_v\right|=\frac{1}{\left|Z\right|}\sqrt{(4U_A^2+U_B^2-4U_A{U}_{B}cos\mathrm{\δ}){\mathrm{\ΔU}}_A^2+U_A^2{\mathrm{\ΔU}}_B^2+(2U_A{U}_B-4U_A^{2}cos\mathrm{\δ}){\mathrm{\ΔU}}_A{\mathrm{\ΔU}}_B}---\left(11\right)$

The computing formula that can obtain I is:

$I=\frac{\left|{\mathrm{\ΔS}}_v\left(i\right)\right|}{\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\left(i\right)\right|+\left|{\mathrm{\ΔS}}_v\left(i\right)\right|}---\left(12\right)$

In formula, Δ S_δIt is the first component, Δ S_vFor second component, i represents data sampling instants, wherein:

$\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\left(i\right)\right|=\frac{U_A\left(i\right)U_B\left(i\right)}{\left|Z\right|}\×\left|\mathrm{\Δ}\mathrm{\δ}\left(i\right)\right|$

$\left|{\mathrm{\ΔS}}_v\left(i\right)\right|=\frac{1}{\left|Z\right|}\sqrt{\begin{array}{c}\left(4U_A^2\right(i)+U_B^2(i)-4U_A(i\left)U_B\right(i\left)\cos \mathrm{\δ}\right(i\left)\right){\mathrm{\ΔU}}_A^2\left(i\right)+U_A^2\left(i\right){\mathrm{\ΔU}}_B^2\left(i\right)\\ +\left(2U_A\right(i\left)U_B\right(i)-4U_A^2(i\left)\cos \mathrm{\δ}\right(i\left)\right){\mathrm{\ΔU}}_A\left(i\right){\mathrm{\ΔU}}_B\left(i\right)\end{array}}.$

Leading Failure Model identification parameter I is calculated as the threshold value judged during identifying by above-mentioned formula.

Based on described identification parameter, step S105, when judging that transient state merit angle unstability and transient voltage unstable phenomenon occur simultaneously The leading Failure Model of system.

In this step, dominate system variable a pair that is mainly based upon structure, according to Failure Model and leading system variable Between relation to leading Failure Model identification.

In one embodiment, it is judged that method can be such that

As 0≤I ＜ ξ, the leading Failure Model of described power system is transient state merit angle Failure Model, when ξ ＜ I≤1, The leading Failure Model of described power system is transient voltage Failure Model, and as I=ξ, power system is in Instability mould Formula；Wherein, ξ is threshold value during Critical unstable mode.

Preferably, ξ=0.5 can be used as threshold value, its value can be analyzed according to following:

Under single Failure Model, disturbed after system only there is pure transient voltage destabilization problems or pure transient state merit angle unstability Problem, in the dominance identification of Failure Model, single Failure Model is considered as a kind of extreme case.Generally with infinitely great female Line accesses single load system and studies pure Transient Voltage Stability problem, as shown in Figure 4, with one machine infinity bus system study pure temporarily State angle stability problem.

Situation shown in Fig. 4 (a), when only there is pure transient voltage unstability, available boundary condition:

δ_A≈δ_B, Δ U_A≠ 0, Δ U_B≠0 (13)

Then:

$\frac{\left|{\mathrm{\ΔS}}_v\right|}{\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\right|+\left|{\mathrm{\ΔS}}_v\right|}=1---\left(14\right)$

Situation shown in Fig. 4 (b), when only there is pure transient state merit angle unstability, available boundary condition:

δ_A≠δ_B, Δ U_A≈ 0, Δ U_B≈0 (15)

Then:

$\frac{\left|{\mathrm{\ΔS}}_v\right|}{\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\right|+\left|{\mathrm{\ΔS}}_v\right|}=0---\left(16\right)$

Under leading Failure Model, the Failure Model of disturbed rear system is divided into the unstability mould taken as the leading factor with transient voltage unstability Formula and the Failure Model taken as the leading factor with transient state merit angle unstability, under leading Failure Model, two kinds of unstable phenomenons exist simultaneously, but with A kind of Failure Model is taken as the leading factor.

In order to preferably analyze the boundary condition under leading Failure Model, the leading Failure Model of research and single mistake further The relation of steady pattern, as it is shown in figure 5, Fig. 5 describes the relation between different Failure Model, under leading Failure Model, no matter Transient state merit angle unstability accounts for leading still transient voltage unstability and accounts for leading, all has:

Δ δ ≠ 0, Δ U ≠ 0 (17)

In oscillatory process, it will be assumed that:

U_A=kU_B (18)

Then:

ΔU_A=k Δ U_B (19)

Consider U_A、U_BBeing the voltage magnitude of oscillation center same interconnection two side bus, variable k has:

k∈[1-ε,1+ε] (20)

Wherein, ε is a less positive number.

Formula (19) is updated to formula (10), formula (11) has:

$\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\right|=\frac{{\mathrm{kU}}_B^2}{\left|Z\right|}\left|\mathrm{\Δ}\mathrm{\δ}\right|---\left(21\right)$

$\left|{\mathrm{\ΔS}}_v\right|=\frac{{\mathrm{kU}}_B\left|{\mathrm{\ΔU}}_B\right|}{\left|Z\right|}\sqrt{4k^2-8kcos\mathrm{\δ}+4}---\left(22\right)$

Then:

$\frac{\left|{\mathrm{\ΔS}}_v\right|}{\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\right|}=\frac{\sqrt{4k^2-8kcos\mathrm{\δ}+4}}{U_B}\×\frac{\left|{\mathrm{\ΔU}}_B\right|}{\left|\mathrm{\Δ}\mathrm{\δ}\right|}---\left(23\right)$

Defined function:

$F\left(k\right)=\frac{\sqrt{4k^2-8kcos\mathrm{\δ}+4}}{U_B}---\left(24\right)$

Have according to formula (20):

$\underset{k\→1}{\lim }F\left(k\right)=\underset{k\→1}{\lim }\frac{\sqrt{4k^2-8k\cos \mathrm{\δ}+4}}{U_B}=\frac{\sqrt{8-8\cos \mathrm{\δ}}}{U_B}=\frac{4\sin (\mathrm{\δ}/2)}{U_B}---\left(25\right)$

The dominance identification of Failure Model is carried out after Transient Instability criterion triggers immediately, and now system operating point is firm Enter transient voltage unstability determined by unstability interval in transient state merit angle determined by P-δ curve or V-P curve interval, therefore formula (25) U in_BAnd δ is finite value, it is impossible to take infinitely small quantity, i.e. function F (k) is bounded function.

When transient state merit angle unstability takes Failure Model as the leading factor, formula (17) is set up, along with the dominance of transient state merit angle unstability is got over When coming the strongest, node voltage variation delta U is more and more less, until final Δ U ≈ 0, now Failure Model shows as pure transient state merit Angle unstability, then have:

$\underset{{\mathrm{\ΔU}}_B\→0}{\lim }\frac{\left|{\mathrm{\ΔS}}_v\right|}{\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\right|}=F\left(k\right)\underset{{\mathrm{\ΔU}}_B\→0}{\lim }\frac{\left|{\mathrm{\ΔU}}_B\right|}{\left|\mathrm{\Δ}\mathrm{\δ}\right|}---\left(26\right)$

Function F (k) is bounded function, then when transient state merit angle unstability takes Failure Model as the leading factor:

$\underset{{\mathrm{\ΔU}}_B\→0}{\lim }\frac{\left|{\mathrm{\ΔS}}_v\right|}{\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\right|}=0---\left(27\right)$

I.e.

$\underset{{\mathrm{\ΔU}}_B\→0}{\lim }\frac{\left|{\mathrm{\ΔS}}_v\right|}{\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\right|+\left|{\mathrm{\ΔS}}_v\right|}=0---\left(28\right)$

When transient voltage unstability takes Failure Model as the leading factor, formula (17) is set up, along with the dominance of transient voltage unstability is got over When coming the strongest, circuit first and last terminal voltage phase angle difference variation delta δ is more and more less, until final Δ δ ≈ 0, now Failure Model table It is now pure transient voltage unstability, then has:

$\underset{\mathrm{\Δ}\mathrm{\δ}\→0}{\lim }\frac{\left|{\mathrm{\ΔS}}_v\right|}{\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\right|}=F\left(k\right)\underset{\mathrm{\Δ}\mathrm{\δ}\→0}{\lim }\frac{\left|{\mathrm{\ΔU}}_B\right|}{\left|\mathrm{\Δ}\mathrm{\δ}\right|}---\left(29\right)$

Function F (k) is bounded function, then when transient voltage unstability takes Failure Model as the leading factor:

$\underset{\mathrm{\Δ}\mathrm{\δ}\→0}{\lim }\frac{\left|{\mathrm{\ΔS}}_v\right|}{\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\right|}=+\mathrm{\∞}---\left(30\right)$

I.e.

$\underset{\mathrm{\Δ}\mathrm{\δ}\→0}{\lim }\frac{\left|{\mathrm{\ΔS}}_v\right|}{\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\right|+\left|{\mathrm{\ΔS}}_v\right|}=1---\left(31\right)$

Particularly, when leading Failure Model is Critical unstable mode, due to

Δ S=Δ S_v+ΔS_δ (32)

As it was previously stated, in transient process after disturbance, Δ S reflects the change of power transmission network running status, and it comprises Two parts component, a part with give, variation delta S of receiving end busbar voltage phase angle difference_δRelevant, another part and sending end, receiving end Variation delta S of busbar voltage amplitude_vRelevant, therefore under Critical unstable mode, it is believed that this two parts component is equal, i.e. Have:

$\frac{\left|{\mathrm{\ΔS}}_v\right|}{\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\right|+\left|{\mathrm{\ΔS}}_v\right|}=\frac{1}{2}---\left(33\right)$

In sum, in actual applications, ξ=0.5 can be taken to judge as threshold value.I.e. as 0≤I ＜ 0.5, The leading Failure Model judging power system is merit angle Failure Model, when 0.5 ＜ I≤1, it is judged that the leading unstability of power system Pattern is transient voltage Failure Model, as I=0.5, it is judged that power system is in Critical unstable mode.

As an embodiment, when power system is in Critical unstable mode, step S106 can be performed further；

Step S106, reads the real-time measurement data in i+T moment, according to described real-time measurement data identification subsequent time electricity The leading Failure Model of Force system；Wherein, T is the sampling period.

It is more than the related embodiment content of technical solution of the present invention, in order to become apparent from the technology of technical solution of the present invention Effect, illustrates an application example the most again.

This application example is as a example by the valve systems such as 3 machine 10 nodes, and as shown in Figure 6, the load model that power system uses is: It is 100% constant-impedance load at B7, is 100% induction-motor load at B10.Three phase short circuit fault, 0.0056s is there is at B6 during 0s Rear cutout removes fault, identifies that process is as follows:

(1) interconnection at the disturbed rear oscillation center place of power system, oscillation center institute is determined by wide area measurement system It is Bus6-Bus8 at interconnection；

(2) extracting the dynamic feature information of oscillation center place interconnection, after fault, data are from the beginning of 0.0056s, dynamically Characteristic information is bus Bus6 and the voltage magnitude of bus Bus8 and phase angle；

(3) two parts component Δ S of the sending end complex power variable quantity of interconnection is calculated_δWith Δ S_v, computing formula is:

${\mathrm{\ΔS}}_{\mathrm{\δ}}\left(i\right)=\[\frac{U_A\left(i\right)U_B\left(i\right)}{\left|Z\right|}cos\left(\mathrm{\δ}\right(i)-a)+j\frac{U_A\left(i\right)U_B\left(i\right)}{\left|Z\right|}sin\left(\mathrm{\δ}\right(i)-a)\]\×\mathrm{\Δ}\mathrm{\δ}\left(i\right)$

$\begin{array}{c}{\mathrm{\ΔS}}_v\left(i\right)=\{\[\frac{2U_A\left(i\right)}{\left|Z\right|}\sin a+\frac{U_B\left(i\right)}{\left|Z\right|}\sin \left(\mathrm{\δ}\right(i)-a)\]+j\[\frac{2U_A\left(i\right)}{\left|Z\right|}\cos a-\frac{U_B\left(i\right)}{\left|Z\right|}\cos \left(\mathrm{\δ}\right(i)-a)\]\}\×{\mathrm{\ΔU}}_A\left(i\right)\\ +\[\frac{U_A\left(i\right)}{\left|Z\right|}\sin \left(\mathrm{\δ}\right(i)-a)-j\frac{U_A\left(i\right)}{\left|Z\right|}\cos \left(\mathrm{\δ}\right(i)-a)\]\×{\mathrm{\ΔU}}_B\left(i\right)\end{array}$

(4) calculating leading Failure Model identification parameter I, computing formula is:

$I=\frac{\left|{\mathrm{\ΔS}}_v\left(i\right)\right|}{\left|{\mathrm{\ΔS}}_{\mathrm{\δ}}\left(i\right)\right|+\left|{\mathrm{\ΔS}}_v\left(i\right)\right|}$

Wherein:

$\left|{\mathrm{\ΔS}}_{\mathrm{\υ}}\left(i\right)\right|=\frac{1}{\left|Z\right|}\sqrt{\begin{array}{c}\left(4U_A^2\right(i)+U_B^2(i)-4U_A(i\left)U_B\right(i\left)cos\mathrm{\Δ}\mathrm{\δ}\right(i\left)\right){\mathrm{\ΔU}}_A^2\left(i\right)+U_A^2\left(i\right){\mathrm{\ΔU}}_B^2\left(i\right)\\ +\left(2U_A\right(i)U_B\left(i\right)-4U_A^2\left(i\right)\cos \mathrm{\δ}\left(i\right)){\mathrm{\ΔU}}_A\left(i\right){\mathrm{\ΔU}}_B\left(i\right)\end{array}}$

(5) based on identification parameter I, it is judged that the leading Failure Model of power system, as 0≤I ＜ 0.5, it is judged that power train The leading Failure Model of system is merit angle Failure Model, when 0.5 ＜ I≤1, it is judged that the leading Failure Model of power system is transient state Voltage Instability pattern, as I=0.5, it is judged that power system is in Critical unstable mode.The result of calculation of identification parameter I such as table 1 Shown in:

Table 1

Understand according to above-mentioned recognition methods, I > 0.5, therefore judge that the leading Failure Model of power system is Voltage Instability mould Formula.

Based on time-domain-simulation method, according to the merit angle of the whole network after Fig. 7 to Fig. 8 disturbance and voltage curve, it may be determined that power system There occurs transient voltage unstability.It follows that the above-mentioned leading Failure Model judging system based on identification parameter I is Voltage Instability It is correct.

(6) according to the real-time measurement data in i+T moment, it is judged that the leading Failure Model of subsequent time system.

To sum up embodiment is visible, present invention power transfer characteristic based on power transmission network, considers active power and nothing simultaneously The impact of merit power, extracts the complex power component relevant to angle stability sex chromosome mosaicism and the multiple merit relevant with voltage stabilization sex chromosome mosaicism Rate component, builds and dominates system variable for a pair and study the relation between different Failure Models and leading system variable, Jin Erti Go out a kind of leading instability mode recognition method.The method is based only upon measured data and calculates, explicit physical meaning, uses letter Single, calculate speed fast.And simulation result shows, the method can effectively identify the leading Failure Model of power system.The program Transient stability analysis based on WAMS information carries out leading Failure Model identification, provides decision-making to depend on for follow-up Transient Stability Control According to.

More than for the leading instability mode recognition method related content of power system, corresponding with the method, the present invention also carries Supply the leading Failure Model identification system of a kind of power system.

With reference to the leading Failure Model identification system structure schematic diagram of the power system that Fig. 9, Fig. 9 are an embodiment, bag Include:

Vibration interconnection identification module 101, for determining place, disturbed rear system oscillation center by wide area measurement system Interconnection；

Characteristic information extracting module 102, for extracting the dynamic feature information of described interconnection from metric data, its In, described dynamic feature information sending end voltage, phase angle and amplitude and the voltage of receiving end, phase angle and amplitude；

Component computing module 103, for calculating the change of described interconnection sending end complex power according to described dynamic feature information First component of amount and second component；Wherein, described first component is that the busbar voltage phase angle difference variable quantity with sending end, receiving end has The component closed, second component is the component relevant to the busbar voltage amplitude variable quantity of sending end, receiving end；

Parameter calculating module 104, for calculating the identification of leading Failure Model according to described first component and second component Parameter I,In formula, Δ S_δIt is the first component, Δ S_vFor second component, i represents data sampling instants；

Based on described identification parameter, pattern recognition module 105, for judging that transient state merit angle unstability and transient voltage unstability are existing The leading Failure Model of system during as occurring simultaneously.

Further, it is also possible to include that identification redirects module 106, it is used for when power system is in Critical unstable mode, Read the real-time measurement data in i+T moment, according to the leading unstability of described real-time measurement data identification subsequent time power system Pattern；Wherein, T is the sampling period.

The leading Failure Model identification system of the power system of the present invention and the leading unstability mould of the power system of the present invention Formula recognition methods one_to_one corresponding, the technical characteristic that the embodiment in the leading instability mode recognition method of above-mentioned power system illustrates And beneficial effect is all be applicable to the embodiment of the leading Failure Model identification system of power system, hereby give notice that.

Each technical characteristic of embodiment described above can combine arbitrarily, for making description succinct, not to above-mentioned reality The all possible combination of each technical characteristic executed in example is all described, but, as long as the combination of these technical characteristics is not deposited In contradiction, all it is considered to be the scope that this specification is recorded.

Embodiment described above only have expressed the several embodiments of the present invention, and it describes more concrete and detailed, but also Can not therefore be construed as limiting the scope of the patent.It should be pointed out that, come for those of ordinary skill in the art Saying, without departing from the inventive concept of the premise, it is also possible to make some deformation and improvement, these broadly fall into the protection of the present invention Scope.Therefore, the protection domain of patent of the present invention should be as the criterion with claims.

Claims (10)

1. the leading instability mode recognition method of a power system, it is characterised in that including:

The interconnection at place, disturbed rear system oscillation center is determined by wide area measurement system；

The dynamic feature information of described interconnection, wherein, described dynamic feature information sending end voltage phase is extracted from metric data Angle and amplitude and the voltage phase angle of receiving end and amplitude；

The first component and the second component of described interconnection sending end complex power variable quantity is calculated according to described dynamic feature information；Its In, described first component is the component relevant with the busbar voltage phase angle difference variable quantity of sending end, receiving end, and second component is and send The component that end, the busbar voltage amplitude variable quantity of receiving end are correlated with；

The identification parameter I of leading Failure Model is calculated according to described first component and second component,Formula In, Δ S_δIt is the first component, Δ S_vFor second component, i represents data sampling instants；

The leading mistake of system when judging that transient state merit angle unstability and transient voltage unstable phenomenon occur simultaneously based on described identification parameter Steady pattern.

The leading instability mode recognition method of power system the most according to claim 1, it is characterised in that described based on institute State identification parameter and judge the step of the leading Failure Model of system when transient state merit angle unstability and transient voltage unstable phenomenon occur simultaneously Suddenly include:

As 0≤I ＜ ξ, the leading Failure Model of described power system is transient state merit angle Failure Model, when ξ ＜ I≤1, described The leading Failure Model of power system is transient voltage Failure Model, and as I=ξ, power system is in Critical unstable mode；Its In, ξ is threshold value during Critical unstable mode.

The leading instability mode recognition method of power system the most according to claim 1, it is characterised in that described by extensively Territory measurement system determines that the step of the interconnection at the disturbed rear oscillation center place of system includes:

After power system is disturbed, by the real-time measurement data of wide area measurement system, identify the oscillation center of system, really Surely the interconnection of oscillation center it is in.

The leading instability mode recognition method of power system the most according to claim 1, it is characterised in that described according to institute State dynamic feature information described first component of interconnection sending end complex power variable quantity of calculating and the step of second component include:

According to oscillation center place interconnection and the direction of tide of reality, power system is equivalent to a sending end, receiving end bright True interacted system model；

According to described interacted system model sending end, the external characteristics of receiving-end system, obtain corresponding equivalent unit list load system；

Under the dynamic situation of change ignoring line parameter circuit value, calculate transmission cross-section complex power variable quantity the first component in transient process And second component.

The leading instability mode recognition method of power system the most according to claim 1, it is characterised in that described extracting During the dynamic feature information of interconnection, in the sampling period of described dynamic feature information and described wide area measurement system The sampling period of PMU measuring unit is identical.

The leading instability mode recognition method of power system the most according to claim 1, it is characterised in that described first point Amount and second component are calculated as follows:

${\mathrm{\ΔS}}_{\mathrm{\δ}}\left(i\right)=\[\frac{U_A\left(i\right)U_B\left(i\right)}{\left|Z\right|}\cos \left(\mathrm{\δ}\left(i\right)-a\right)+j\frac{U_A\left(i\right)U_B\left(i\right)}{\left|Z\right|}\sin \left(\mathrm{\δ}\left(i\right)-a\right)\]\×\mathrm{\Δ}\mathrm{\δ}\left(i\right)$

$\begin{array}{c}{\mathrm{\ΔS}}_v\left(i\right)=\{\[\frac{2U_A\left(i\right)}{\left|Z\right|}\sin a+\frac{U_B\left(i\right)}{\left|Z\right|}sin\left(\mathrm{\δ}\right(i)-a)\]+j\[\frac{2U_A\left(i\right)}{\left|Z\right|}\cos a-\frac{U_B\left(i\right)}{\left|Z\right|}cos\left(\mathrm{\δ}\right(i)-a)\]\}\×{\mathrm{\ΔU}}_A\left(i\right)\\ +\[\frac{U_A\left(i\right)}{\left|Z\right|}\sin \left(\mathrm{\δ}\left(i\right)-a\right)-j\frac{U_A\left(i\right)}{\left|Z\right|}\cos \left(\mathrm{\δ}\left(i\right)-a\right)\]\×{\mathrm{\ΔU}}_B\left(i\right)\end{array}$

In formula, Z=R_Σ+jX_Σ=| Z | ∠ arctg (X_Σ/R_Σ), α=pi/2-arctg (X_Σ/R_Σ), Δ δ (i)=δ (i)-δ (i- 1), Δ U_A(i)=U_A(i)-U_A(i-1), Δ U_B(i)=U_B(i)-U_B(i-1)；Wherein, the voltage of the i-th moment of oscillation center sending end Amplitude is U_AI (), sending end voltage phase angle is δ_AI (), receiving end voltage magnitude is U_BI (), receiving end voltage phase angle is δ_B(i), sending end, The phase difference of voltage of receiving end is δ (i)=δ_A(i)-δ_BI (), the line resistance of interconnection is R_Σ, the line reactance of interconnection is X_Σ。

The leading instability mode recognition method of power system the most according to claim 6, it is characterised in that wherein:

$\left|{\mathrm{\ΔS}}_v\left(i\right)\right|=\frac{1}{\left|Z\right|}\sqrt{\begin{array}{c}\left(4U_A^2\right(i)+U_B^2(i)-4U_A(i\left)U_B\right(i\left)cos\mathrm{\δ}\right(i\left)\right){\mathrm{\ΔU}}_A^2\left(i\right)+U_A^2\left(i\right){\mathrm{\ΔU}}_B^2\left(i\right)\\ +\left(2U_A\left(i\right)U_B\left(i\right)-4U_A^2\left(i\right)\cos \mathrm{\δ}\left(i\right)\right){\mathrm{\ΔU}}_A\left(i\right){\mathrm{\ΔU}}_B\left(i\right)\end{array}}.$

The leading instability mode recognition method of power system the most according to claim 1, it is characterised in that described ξ= 0.5。

The leading instability mode recognition method of power system the most according to claim 1, it is characterised in that also include:

When power system is in Critical unstable mode, read the real-time measurement data in i+T moment, according to described real-time measurement number According to the leading Failure Model identifying subsequent time power system；Wherein, T is the sampling period.

10. the leading Failure Model identification system of a power system, it is characterised in that including:

Vibration interconnection identification module, for determining the contact at place, disturbed rear system oscillation center by wide area measurement system Line；

Characteristic information extracting module, for extracting the dynamic feature information of described interconnection from metric data, wherein, described dynamic State characteristic information sending end voltage phase angle and amplitude and the voltage phase angle of receiving end and amplitude；

Component computing module, for calculating the first of described interconnection sending end complex power variable quantity according to described dynamic feature information Component and second component；Wherein, described first component is divides relevant with the busbar voltage phase angle difference variable quantity of sending end, receiving end Amount, second component is the component relevant to the busbar voltage amplitude variable quantity of sending end, receiving end；

Parameter calculating module, for calculating the identification parameter I of leading Failure Model according to described first component and second component,In formula, Δ S_δIt is the first component, Δ S_vFor second component, i represents data sampling instants；

Based on described identification parameter, pattern recognition module, for judging that transient state merit angle unstability and transient voltage unstable phenomenon are sent out simultaneously The leading Failure Model of system time raw.