CN103632043A - Dominant power system instability mode recognition method based on real-time measurement response information - Google Patents

Abstract

The invention provides a dominant power system instability mode recognition method based on real-time measurement response information. According to the method, a dominant instability mode of a system is judged when a power angle instability phenomenon and a voltage instability phenomenon occur at the same time, and a decision basis is provided for subsequent transient stability emergency control. The method includes the steps of determining a power transmission cross section of the multi-machine interconnected electric power system, obtaining real-time measurement information of the power transmission cross section, calculating dominant system variables which can reflect a system instability mode according to the real-time measurement information, calculating the dominant instability mode identification index according to the dominant system variables, and determining the dominant instability mode of the system according to the dominant instability mode identification index. The method is totally based on the real-time measurement information, dynamic properties of the system are considered fully, and the dominant instability mode of the system when the power angle instability phenomenon and the voltage instability phenomenon occur at the same time can be recognized accurately.

Description

The leading Failure Model recognition methods of a kind of electric system based on actual measurement response message

Technical field

The present invention relates to field of power, be specifically related to the leading Failure Model recognition methods of a kind of electric system based on actual measurement response message.

Background technology

Transient state merit angle unstability and transient voltage unstability are the two kind forms of expression of system in transient state process after fault.When system unstability, merit angle unstability likely causes collapse of voltage, and collapse of voltage also likely causes merit angle unstability.Transient rotor angle stability problem and Transient Voltage Stability problem be weave in often, only from the be not easily distinguishable Failure Model of system after fault of the form of expression of merit angle, voltage.Yet system unstability is inevitable is taken as the leading factor by a kind of Failure Model, different Failure Models may occur in succession due to the variation of system condition.Merit angle unstability and Voltage Instability in Analysis on Mechanism, stablize the aspects such as control measure and be essentially different.Therefore,, for transient stability control system, after detecting the instability status of system, leading Failure Model that must further clear and definite system, just can guarantee the validity of transient state control measure.The detection of system instability status, mainly depends on INSTABILITY CRITERION, has developed Practical criterion and the Theoretical Criterion of multiple merit angle unstability and Voltage Instability at present.The development of these criterions, for the dominance identification of follow-up system Failure Model is laid a good foundation.

The dominance identification of Failure Model, is necessary angle stability problem and Voltage-stabilizing Problems to analyze as an organic whole, and going of can not isolating treated.In recent years, existing many documents have been studied and have proposed different leading Failure Model recognition methodss to the correlativity of angle stability and voltage stabilization.As followed the tracks of based on Dai Weinan equivalent parameters, can obtain the method for discrimination of Voltage Instability and merit angle unstability, by the Dai Weinan equivalent parameters after fault, change the Failure Model of judgement system.Concept based on generator matrix and matrix of loadings, according to the relation between characteristic root of a matrix variation and system Failure Model, can obtain judging the method for system voltage unstability and merit angle unstability.Under unified energy function framework, study angle stability and Voltage-stabilizing Problems, set up the relation between I class unstable equilibrium point (UEP-unstable equilibrium point) and different Failure Models, the UEP of voltage stabilization pattern and the UEP of angle stability pattern have been proposed, with the Failure Model of this compartment system.In addition, for correct angle stability and the voltage stabilization distinguished, IEEE/CIGRE has provided explanation in power system stability definition and classification report: the differentiation of angle stability and voltage stabilization is not the weak coupling relation based between active power/merit angle and reactive power/voltage magnitude, the impact of meritorious and reactive power flow before angle stability and voltage stabilization are all disturbed, two kinds of stable should differentiations based on the leading system variable that stands one group of specific phase reacting force of permanent disequilibrium and occur subsequently when unstable.

Summary of the invention

The present invention relates to the leading Failure Model recognition methods of a kind of electric system based on actual measurement response message, the leading Failure Model of system when judgement merit angle unstable phenomenon and Voltage Instability phenomenon occur simultaneously, for follow-up transient stability emergency control provides decision-making foundation, the method comprises:

Step S1, the information of measuring by WAMS measurement system is determined the transmission cross-section of described multimachine interconnected electric power system after fault;

Step S2, the T of take periodically obtains the transmission cross-section dynamic feature information that can reflect described multimachine interconnected electric power system dynamic perfromance as the sampling period by described WAMS measurement system;

Step S3, according to described transmission cross-section characteristic information, calculates two kinds of leading system variables of the leading Failure Model of energy reflection system;

Step S4, according to calculating resulting leading system variable, calculates leading Failure Model distinguishing indexes;

Step S5, according to described leading Failure Model distinguishing indexes S, judges whether two kinds of leading system variables equate, are, leading Failure Model None-identified, execution step S6; No, judging leading Failure Model is merit angle unstability or Voltage Instability;

Step S6, when judging that described multimachine interconnected electric power system is after fault during leading Failure Model constantly of i, the value that i is set is i=i+T, execution step S1.

Further, in described step S1, when the information of measuring by WAMS measurement system is determined the transmission cross-section of described multimachine interconnected electric power system after fault, transmission cross-section should lose synchronous sending between receiving end two district systems.

Further, in described step S2, the information of measuring according to WAMS measurement system is determined the interconnection that the transmission cross-section of system comprises after fault.When interconnection has many, the information on unstability interconnection of getting is as dynamic feature information.Described transmission cross-section dynamic feature information comprises not active power, interconnection first and last terminal voltage amplitude and the interconnection first and last terminal voltage phase angle of unstability interconnection on transmission cross-section in the same time; Wherein, after fault, on i moment transmission cross-section, the active power of k bar interconnection is interconnection first and last terminal voltage phase angle is respectively

interconnection first and last terminal voltage amplitude is respectively

Further, in described step S2, from fault, start periodically to obtain the contact section dynamic feature information that can reflect multimachine interconnected electric power system dynamic perfromance by described WAMS measurement system, the sampling period T of described contact section dynamic feature information is identical with the sampling period of PMU measuring unit in described WAMS measurement system;

Further, in described step S3, according to described transmission cross-section characteristic information, calculate the leading system variable of the leading Failure Model of energy reflection system, computing method are as follows:

After fault, on the i moment and i-T described transmission cross-section of the moment, the active power of k bar interconnection is respectively

with

the i active power variable quantity of k bar interconnection constantly for:

${\mathrm{\ΔP}}_{\mathrm{ek}}^i=P_{\mathrm{ek}}^i-P_{\mathrm{ek}}^{i-T};$

After fault, on i described transmission cross-section of the moment, the first and last terminal voltage amplitude of k bar interconnection is respectively

with

after fault, on i-T described transmission cross-section of the moment, the first and last terminal voltage amplitude of k bar interconnection is respectively

with i k bar interconnection first and last terminal voltage amplitude variable quantity constantly

with

be respectively:

$\begin{array}{cc}{\mathrm{\ΔV}}_{k1}^i=V_{k1}^i-V_{k1}^{i-T}& {\mathrm{\ΔV}}_{k2}^i=V_{k2}^i-V_{k2}^{i-T}\end{array}$

The first and last terminal voltage phase angle difference of k bar interconnection on the i moment and i-T described transmission cross-section of the moment after fault with

be respectively:

$\begin{array}{cc}{\mathrm{\δ}}_k^i={\mathrm{\δ}}_{k1}^i-{\mathrm{\δ}}_{k2}^i& {\mathrm{\δ}}_k^{i-T}={\mathrm{\δ}}_{k1}^{i-T}-{\mathrm{\δ}}_{k2}^{i-T}\end{array}$

The i variable quantity of the first and last terminal voltage phase angle difference of k bar interconnection on described transmission cross-section constantly after fault

for:

${\mathrm{\Δ\δ}}_k^i={\mathrm{\δ}}_k^i-{\mathrm{\δ}}_k^{i-T}$

I energy reflection constantly system is dominated the leading system variable of Failure Model with

be respectively:

${\mathrm{\ΔP}}_{\mathrm{k\δ}}^i=\frac{V_{k1}^i{V}_{k2}^i}{\left|Z_k\right|}\cos ({\mathrm{\δ}}_k^i-\mathrm{\α})\·{\mathrm{\Δ\δ}}_k^i$

${\mathrm{\ΔP}}_{\mathrm{kv}}^i=(\frac{{2V}_{k1}^i}{\left|Z_k\right|}\sin \mathrm{\α}+\frac{V_{k2}^i}{\left|Z_k\right|}\sin ({\mathrm{\δ}}_k^i-\mathrm{\α}))\·{\mathrm{\ΔV}}_{k1}^i+\frac{V_{k1}^i}{\left|Z_k\right|}\·\sin ({\mathrm{\δ}}_k^i-\mathrm{\α})\·{\mathrm{\ΔV}}_{k2}^i$

Wherein, Z _kbe k bar interconnection line impedance, the complementary angle that α is angle of impedance, Z _k=R _Σ+ jX _Σ=| Z| ∠ arctgX _Σ/ R _Σ, α=pi/2-arctgX _Σ/ R _Σ, Z is modulus of impedance, j is negative variable, X _Σbe all reactance on k bar interconnection circuit, R _Σbe all resistance on k bar interconnection circuit.

Further, in described step S4, according to calculating resulting leading system variable, calculate leading Failure Model distinguishing indexes S, computing method are:

$S=\frac{|{\mathrm{\ΔP}}_{\mathrm{k\δ}}^i-{\mathrm{\ΔP}}_{\mathrm{ek}}^i|}{|{\mathrm{\ΔP}}_{\mathrm{k\δ}}^i-{\mathrm{\ΔP}}_{\mathrm{ek}}^i|+|{\mathrm{\ΔP}}_{\mathrm{kv}}^i-{\mathrm{\ΔP}}_{\mathrm{ek}}^i|}$

Further, in described step S5, according to leading Failure Model distinguishing indexes, the leading Failure Model of judgement system, method of discrimination is:

When

time, merit angle unstability is taken Failure Model as the leading factor;

When time, Voltage Instability is taken Failure Model as the leading factor;

When

time, two kinds of components now

with

equate, multimachine interconnected electric power system is in critical conditions, and the leading Failure Model None-identified of multimachine interconnected electric power system, need to wait until that next judges constantly;

Beneficial effect of the present invention comprises:

The leading Failure Model recognition methods of a kind of electric system based on actual measurement response message provided by the invention, the transmission cross-section of the information identification multimachine interconnected electric power system of measuring by WAMS measurement system, extract the real-time measurement information of transmission cross-section, according to real-time measurement information, calculate the leading system variable that can reflect system Failure Model, according to leading system variable, calculate leading Failure Model distinguishing indexes, according to leading Failure Model distinguishing indexes, determine the leading Failure Model of system, for follow-up transient stability emergency control provides decision-making foundation.

The method is completely based on real-time measurement information, and the real-time response information that wherein electromagnetic power, voltage magnitude, voltage phase angle all can be measured by WAMS measurement system directly obtains, and makes identification more directly perceived quick, makes this recognition methods have more practicality.

Accompanying drawing explanation

Be illustrated in figure 1 the leading Failure Model recognition methods process flow diagram of a kind of electric system based on actual measurement response message provided by the invention;

Be illustrated in figure 2 the receiving-end system schematic diagram that send provided by the invention;

Be illustrated in figure 3 equivalent unit list load system structural representation provided by the invention;

Be illustrated in figure 4 the schematic diagram of embodiment of the grid structure of region provided by the invention multimachine interconnected electric power system;

Be illustrated in figure 5 the power-angle curve after the multimachine interconnected electric power system fault of region provided by the invention;

Be illustrated in figure 6 the voltage curve after the multimachine interconnected electric power system fault of region provided by the invention;

Be illustrated in figure 7 the power-angle curve of taking to cut machine measure rear region multimachine interconnected electric power system provided by the invention;

Be illustrated in figure 8 the voltage curve of taking to cut machine measure rear region multimachine interconnected electric power system provided by the invention.

Embodiment

The invention provides a kind of transient state merit angle unstability based on real-time measurement information and the dominance recognition methods of transient voltage unstability, the leading Failure Model of system when judgement merit angle unstable phenomenon and Voltage Instability phenomenon occur simultaneously, for follow-up transient stability emergency control provides decision-making foundation.By WAMS(Wide Area Measurement System, the transmission cross-section of the information identification multimachine interconnected electric power system that wide area monitoring system) measurement system is measured, extraction can reflect the dynamic feature information of leading Failure Model between oscillatory system, according to this dynamic feature information, the leading Failure Model of multimachine interconnected electric power system is carried out to Real time identification.Concrete, as shown in Figure 1, as shown in Figure 1, the method comprises the process flow diagram of the method:

Step S1, the information of measuring by WAMS measurement system is determined the transmission cross-section of described multimachine interconnected electric power system after fault;

Step S2, the T of take periodically obtains the transmission cross-section characteristic information that can reflect described multimachine interconnected electric power system dynamic perfromance as the sampling period by described WAMS measurement system;

Step S3, according to described transmission cross-section characteristic information, calculates the leading system variable of the leading Failure Model of energy reflection system;

Step S4, according to calculating resulting leading system variable, calculates leading Failure Model distinguishing indexes;

Step S5, according to leading Failure Model distinguishing indexes, the leading Failure Model of judgement system: when

time, merit angle unstability is taken Failure Model as the leading factor; When

time, Voltage Instability is taken Failure Model as the leading factor; When

time, now two kinds of leading system variables equate, and multimachine interconnected electric power system is in critical conditions, and the leading Failure Model None-identified of system, need to wait until that next judges constantly, execution step S6;

Step S6, cannot judge described multimachine interconnected electric power system i leading Failure Model constantly after fault, and the value that i is set is i=i+T, execution step S1.

The method, completely based on real-time measurement information, has taken into full account the dynamic perfromance of system, the leading Failure Model of system in the time of accurately identifying merit angle unstable phenomenon and Voltage Instability phenomenon and occur simultaneously.

The effect of recognition methods of the present invention is that leading Failure Model system being lost after stablizing by dominance distinguishing indexes is that merit angle unstability or Voltage Instability are identified, this recognition methods can be used alone, and also can combine use with the INSTABILITY CRITERION in No. CN201310008091.9 invention.Dominance distinguishing indexes itself does not have and judges whether system loses stable ability, whether can first use No. CN201310008091.9 INSTABILITY CRITERION in invention to judge system loses stable, be, by the leading Failure Model of recognition methods judgement of the present invention, be merit angle unstability or Voltage Instability again, as follow-up emergency control, provide decision-making foundation.

Embodiment mono-:

Embodiment mono-provided by the invention is the embodiment of the dominance recognition methods of a kind of transient state merit angle unstability based on real-time measurement information provided by the invention and transient voltage unstability.

Concrete, in this embodiment, the leading Failure Model real time discriminating of multimachine interconnected electric power system starts to measure by WAMS system from fault.

In step S1, by the metrical information of WAMS systematic survey, determine the transmission cross-section of multimachine interconnected electric power system after fault, the interconnection of identification on transmission cross-section, thus multimachine interconnected electric power system is divided into and send receiving end two district systems.

In step S2, from fault, start periodically to obtain the transmission cross-section dynamic feature information that can reflect multimachine interconnected electric power system dynamic perfromance by WAMS measurement system, the sampling period T of this transmission cross-section dynamic feature information and (the Phasor Measurement Unit of the PMU in WAMS measurement system, synchronous phase angle measuring unit) sampling period of measuring unit identical, comprise not active power, circuit first and last terminal voltage amplitude and the phase angle of different unstability interconnections on transmission cross-section in the same time.Wherein, after fault, on i moment transmission cross-section, the active power of k bar interconnection is

interconnection first and last terminal voltage phase angle is respectively

voltage magnitude is

The schematic diagram that send receiving end two district systems as shown in Figure 2, wherein region A is sending, and its external characteristics has generator character, and region B is receiving-end system, and its external characteristics has load character.According to the external characteristic of sending receiving-end system, can be unit list load system by its equivalence, as shown in Figure 3.

According to principle and the method for the leading Failure Model of transmission cross-section actual measurement response message recognition system, be:

The electromagnetic power of carrying on transmission cross-section is:

$P=\frac{V_A^2}{\left|Z\right|}\sin \mathrm{\α}+\frac{V_A{V}_B}{\left|Z\right|}\sin (\mathrm{\δ}-\mathrm{\α})$

Line impedance Z=R wherein _Σ+ jX _Σ=| Z| ∠ arctgX _Σ/ R _Σ, phase angle difference δ=δ _a-δ _b, α=pi/2-arctgX _Σ/ R _Σ.Ignore the variation of line parameter circuit value in transient state process, in transient state process, the total differential of transmission cross-section electromagnetic power is:

$\mathrm{dP}=\frac{V_A{V}_B}{\left|Z\right|}\cos (\mathrm{\δ}-\mathrm{\α})\·\mathrm{d\δ}+(\frac{{2V}_A}{\left|Z\right|}\sin \mathrm{\α}+\frac{V_B}{\left|Z\right|}\sin (\mathrm{\δ}-\mathrm{\α}))\·{\mathrm{dV}}_A+\frac{V_A}{\left|Z\right|}\sin (\mathrm{\δ}-\mathrm{\α})\·{\mathrm{dV}}_B$

Difference replaces differential to have

$\mathrm{\ΔP}=\frac{V_A{V}_B}{\left|Z\right|}\cos (\mathrm{\δ}-\mathrm{\α})\·\mathrm{\Δ\δ}+(\frac{{2V}_A}{\left|Z\right|}\sin \mathrm{\α}+\frac{V_B}{\left|Z\right|}\sin (\mathrm{\δ}-\mathrm{\α}))\·{\mathrm{\ΔV}}_A+\frac{V_A}{\left|Z\right|}\sin (\mathrm{\δ}-\mathrm{\α})\·{\mathrm{\ΔV}}_B$

Analysis above formula is known, and on transmission cross-section, the variation of power is the function of two ends busbar voltage amplitude variable quantity and phase difference of voltage variable quantity.Above formula is rewritten as:

$\mathrm{\ΔP}=\frac{\∂P}{\∂\mathrm{\δ}}\·\mathrm{\Δ\δ}+\frac{\∂P}{\∂V}\·\mathrm{\ΔV}={\mathrm{\ΔP}}_{\mathrm{\δ}}+{\mathrm{\ΔP}}_v$

Wherein:

${\mathrm{\ΔP}}_{\mathrm{\δ}}=\frac{V_A{V}_B}{\left|Z\right|}\cos (\mathrm{\δ}-\mathrm{\α})\·\mathrm{\Δ\δ}$

${\mathrm{\ΔP}}_v=(\frac{{2V}_A}{\left|Z\right|}\sin \mathrm{\α}+\frac{V_B}{\left|Z\right|}\sin (\mathrm{\δ}-\mathrm{\α}))\·{\mathrm{\ΔV}}_A+\frac{V_A}{\left|Z\right|}\sin (\mathrm{\δ}-\mathrm{\α})\·{\mathrm{\ΔV}}_B$

From above formula, in transient state process, the variable quantity of transmission cross-section active power comprises two parts component: a part and busbar voltage phase angular dependence (-dance) are the function of busbar voltage phase angle difference variable quantity; Another part and busbar voltage magnitude correlation are the function of busbar voltage amplitude variable quantity.In transient state process after disturbance, variable △ P _δ, △ P _vdetermining that between interacted system, the power on transmission cross-section changes, and then affecting system-wide stability.Therefore, can be by △ P _δwith △ P _vas a pair of leading system variable, come angle stability problem and the Voltage-stabilizing Problems of Study system.

When Voltage Instability is taken Failure Model as the leading factor, from voltage stability, defined, the power supply capacity to load of system cannot meet workload demand, and the actual electromagnetic power obtaining of loading is less than workload demand, has:

P _e=P _l<P _L

P wherein _lfor the meritorious demand of actual load, suppose:

P _L=P _l+△P′=(1+k)P _l?k∈(0,+∞)

?

(1+k)P _l>P _e

?

$(1+k)\left|\frac{{\mathrm{dP}}_l}{\mathrm{dt}}\right|>\left|\frac{{\mathrm{dP}}_e}{\mathrm{dt}}\right|$

Further have:

$(1+k)|\frac{{\mathrm{dP}}_l}{\mathrm{dV}}\&CenterDot;\frac{\mathrm{dV}}{\mathrm{dt}}|>|\frac{{\mathrm{dP}}_e}{\mathrm{d\&delta;}}\&CenterDot;\frac{\mathrm{d\&delta;}}{\mathrm{dt}}|$

?

$(1+k)|\frac{{\mathrm{dP}}_l}{\mathrm{dV}}\&CenterDot;\mathrm{\&Delta;V}|>|\frac{{\mathrm{dP}}_e}{\mathrm{d\&delta;}}\&CenterDot;\mathrm{\&Delta;\&delta;}|$

Can obtain:

$\frac{|\frac{{\mathrm{dP}}_l}{\mathrm{dv}}\&CenterDot;\mathrm{\&Delta;V}|}{|\frac{{\mathrm{dP}}_l}{\mathrm{dV}}\&CenterDot;\mathrm{\&Delta;V}|+|\frac{{\mathrm{dP}}_e}{\mathrm{d\&delta;}}\&CenterDot;\mathrm{\&Delta;\&delta;}|}>\frac{1}{k+2}$

Due to k ∈ (0 ,+∞), have:

When Voltage Instability accounts for when leading, above formula is permanent to be set up, and has:

$\frac{|\frac{{\mathrm{dP}}_l}{\mathrm{dv}}\&CenterDot;\mathrm{\&Delta;V}|}{|\frac{{\mathrm{dP}}_l}{\mathrm{dV}}\&CenterDot;\mathrm{\&Delta;V}|+|\frac{{\mathrm{dP}}_e}{\mathrm{d\&delta;}}\&CenterDot;\mathrm{\&Delta;\&delta;}|}=\frac{\left|{\mathrm{\&Delta;P}}_v\right|}{\left|{\mathrm{\&Delta;P}}_v\right|+\left|{\mathrm{\&Delta;P}}_{\mathrm{\&delta;}}\right|}>\frac{1}{2}$

When merit angle unstability is taken Failure Model as the leading factor, from angle stability, defined, on generator amature, there is uneven torque, have:

P _l=P _e<P _m

Suppose

P _m=P _e+△P″=(1+k)P _e?k∈(0,+∞)

?

(1+k)P _e>P _l

Have:

$(1+k)\left|\frac{{\mathrm{dP}}_e}{\mathrm{dt}}\right|>\left|\frac{{\mathrm{dP}}_l}{\mathrm{dt}}\right|$

Further have:

$(1+k)|\frac{{\mathrm{dP}}_e}{\mathrm{d\&delta;}}\&CenterDot;\frac{\mathrm{d\&delta;}}{\mathrm{dt}}|>|\frac{{\mathrm{dP}}_l}{\mathrm{dV}}\&CenterDot;\frac{\mathrm{dV}}{\mathrm{dt}}|$

?

$(1+k)|\frac{{\mathrm{dP}}_e}{\mathrm{d\&delta;}}\&CenterDot;\mathrm{\&Delta;\&delta;}|>|\frac{{\mathrm{dP}}_l}{\mathrm{dV}}\&CenterDot;\mathrm{\&Delta;V}|$

Can obtain:

$\frac{|\frac{{\mathrm{dP}}_l}{\mathrm{dv}}\&CenterDot;\mathrm{\&Delta;V}|}{|\frac{{\mathrm{dP}}_l}{\mathrm{dV}}\&CenterDot;\mathrm{\&Delta;V}|+|\frac{{\mathrm{dP}}_e}{\mathrm{d\&delta;}}\&CenterDot;\mathrm{\&Delta;\&delta;}|}<\frac{k+1}{k+2}$

Due to k ∈ (0 ,+∞), have:

When merit angle unstability accounts for when leading, above formula is permanent to be set up, and has:

$\frac{|\frac{{\mathrm{dP}}_l}{\mathrm{dv}}\&CenterDot;\mathrm{\&Delta;V}|}{|\frac{{\mathrm{dP}}_l}{\mathrm{dV}}\&CenterDot;\mathrm{\&Delta;V}|+|\frac{{\mathrm{dP}}_e}{\mathrm{d\&delta;}}\&CenterDot;\mathrm{\&Delta;\&delta;}|}=\frac{\left|{\mathrm{\&Delta;P}}_v\right|}{\left|{\mathrm{\&Delta;P}}_v\right|+\left|{\mathrm{\&Delta;P}}_{\mathrm{\&delta;}}\right|}<\frac{1}{2}$

Can be defined as follows leading Failure Model distinguishing indexes S:

$S=\frac{\left|{\mathrm{\&Delta;P}}_v\right|}{\left|{\mathrm{\&Delta;P}}_v\right|+\left|{\mathrm{\&Delta;P}}_{\mathrm{\&delta;}}\right|}$

Have:

$S=\frac{|{\mathrm{\&Delta;P}}_{\mathrm{\&delta;}}-\mathrm{\&Delta;P}|}{|{\mathrm{\&Delta;P}}_{\mathrm{\&delta;}}-\mathrm{\&Delta;P}|+|{\mathrm{\&Delta;P}}_v-\mathrm{\&Delta;P}|}$

Mathematical meaning and the physical significance of leading Failure Model distinguishing indexes S are soluble as follows: dominance distinguishing indexes S adopts transmission cross-section power change amount △ P curve and a minute discharge curve △ P _δ, △ P _vbetween geometric distance represent.When merit angle unstability is taken pattern as the leading factor, △ P curve and △ P _δdistance between curve is less, and the coincidence degree of two curves is higher, and under extreme case, two curves overlap, now △ P _δit is the principal element that causes that △ P changes.Otherwise, △ P _vit is the principal element that △ P changes.

In sum, the system Failure Model dominance recognition methods based on leading Failure Model distinguishing indexes S is as follows:

When

time, merit angle unstability is taken Failure Model as the leading factor;

When

time, Voltage Instability is taken Failure Model as the leading factor;

When time, two kinds of component △ P now _δwith △ P _vequate, system is in critical conditions, and the leading Failure Model None-identified of system, need to wait until that next judges constantly;

In step S3, according to described transmission cross-section characteristic information, calculate the leading system variable of the leading Failure Model of energy reflection system, computing method are as follows:

After fault, on the i moment and i-T described transmission cross-section of the moment, the active power of k bar interconnection is respectively

with

the i active power variable quantity of k bar interconnection constantly for:

${\mathrm{\&Delta;P}}_{\mathrm{ek}}^i=P_{\mathrm{ek}}^i-P_{\mathrm{ek}}^{i-T};$

After fault, on i described transmission cross-section of the moment, the first and last terminal voltage amplitude of k bar interconnection is respectively

with

after fault, on i-T described transmission cross-section of the moment, the first and last terminal voltage amplitude of k bar interconnection is respectively

with

i k bar interconnection first and last terminal voltage amplitude variable quantity constantly

with

be respectively:

$\begin{array}{cc}{\mathrm{\&Delta;V}}_{k1}^i=V_{k1}^i-V_{k1}^{i-T}& {\mathrm{\&Delta;V}}_{k2}^i=V_{k2}^i-V_{k2}^{i-T}\end{array}$

The first and last terminal voltage phase angle difference of k bar interconnection on the i moment and i-T described transmission cross-section of the moment after fault

with

be respectively:

$\begin{array}{cc}{\mathrm{\&delta;}}_k^i={\mathrm{\&delta;}}_{k1}^i-{\mathrm{\&delta;}}_{k2}^i& {\mathrm{\&delta;}}_k^{i-T}={\mathrm{\&delta;}}_{k1}^{i-T}-{\mathrm{\&delta;}}_{k2}^{i-T}\end{array}$

The i variable quantity of the first and last terminal voltage phase angle difference of k bar interconnection on described transmission cross-section constantly after fault

for:

${\mathrm{\&Delta;\&delta;}}_k^i={\mathrm{\&delta;}}_k^i-{\mathrm{\&delta;}}_k^{i-T}$

I energy reflection constantly system is dominated the leading system variable of Failure Model

with

be respectively:

${\mathrm{\&Delta;P}}_{\mathrm{k\&delta;}}^i=\frac{V_{k1}^i{V}_{k2}^i}{\left|Z_k\right|}\cos ({\mathrm{\&delta;}}_k^i-\mathrm{\&alpha;})\&CenterDot;{\mathrm{\&Delta;\&delta;}}_k^i$

${\mathrm{\&Delta;P}}_{\mathrm{kv}}^i=(\frac{{2V}_{k1}^i}{\left|Z_k\right|}\sin \mathrm{\&alpha;}+\frac{V_{k2}^i}{\left|Z_k\right|}\sin ({\mathrm{\&delta;}}_k^i-\mathrm{\&alpha;}))\&CenterDot;{\mathrm{\&Delta;V}}_{k1}^i+\frac{V_{k1}^i}{\left|Z_k\right|}\&CenterDot;\sin ({\mathrm{\&delta;}}_k^i-\mathrm{\&alpha;})\&CenterDot;{\mathrm{\&Delta;V}}_{k2}^i$

K bar interconnection line impedance Z wherein _k=R _Σ+ jX _Σ=| Z| ∠ arctgX _Σ/ R _Σ, α=pi/2-arctgX _Σ/ R _Σ.

In step S4, according to calculating resulting leading system variable, calculate leading Failure Model distinguishing indexes S, computing method are:

$S=\frac{|{\mathrm{\&Delta;P}}_{\mathrm{k\&delta;}}^i-{\mathrm{\&Delta;P}}_{\mathrm{ek}}^i|}{|{\mathrm{\&Delta;P}}_{\mathrm{k\&delta;}}^i-{\mathrm{\&Delta;P}}_{\mathrm{ek}}^i|+|{\mathrm{\&Delta;P}}_{\mathrm{kv}}^i-{\mathrm{\&Delta;P}}_{\mathrm{ek}}^i|}$

In step S5, according to leading Failure Model distinguishing indexes, the leading Failure Model of judgement system: when

time, merit angle unstability is taken Failure Model as the leading factor; When

time, Voltage Instability is taken Failure Model as the leading factor; When

time, two kinds of components now

with

in critical conditions, the leading Failure Model None-identified of system, need to wait until that next judges constantly, execution step S6;

Embodiment bis-:

The embodiment bis-of the dominance recognition methods of a kind of transient state merit angle unstability based on real-time measurement information provided by the invention and transient voltage unstability is based on IEEE9 node system, as shown in Figure 4, the computational tool of taking is PSD-FDS(electric power system full dynamic simulation program), the disturbance response data that obtain with simulated program are simulated the real-time measurement data of wide area measurement system, and in system, each load is constant-impedance.During 0s there is three-phase shortcircuit in circuit bus5-bus7,0.21s failure removal, monitoring interconnection Bus9-Bus6.

Step S1': the disturbance response data that obtain by simulated program are simulated the real-time measurement data of wide area measurement system, determine the interconnection on transmission cross-section is interconnection Bus9-Bus6 in this example.

Step S2': extraction can reflect the transmission cross-section characteristic information of system Failure Model, characteristic quantity is i active power constantly after interconnection Bus9-Bus6 fault

interconnection first and last terminal voltage phase angle voltage magnitude the whole network power-angle curve and voltage curve are as shown in Figure 5, Figure 6.From merit angular difference curve and voltage curve, merit angle unstability and Voltage Instability exist simultaneously.Only, from the form of expression of merit angle and voltage, be difficult to the leading Failure Model of compartment system, therefore be also difficult to select effective control measure.

Step S3': according to described transmission cross-section characteristic information, calculate the leading system variable of the leading Failure Model of energy reflection system, computing method are as follows:

After fault, on the i moment and i-T described transmission cross-section of the moment, the active power of k bar interconnection is respectively

with

the i active power variable quantity of k bar interconnection constantly for:

${\mathrm{\&Delta;P}}_{\mathrm{ek}}^i=P_{\mathrm{ek}}^i-P_{\mathrm{ek}}^{i-T};$

After fault, on i described transmission cross-section of the moment, the first and last terminal voltage amplitude of k bar interconnection is respectively

with after fault, on i-T described transmission cross-section of the moment, the first and last terminal voltage amplitude of k bar interconnection is respectively

with

i k bar interconnection first and last terminal voltage amplitude variable quantity constantly

with

be respectively:

$\begin{array}{cc}{\mathrm{\&Delta;V}}_{k1}^i=V_{k1}^i-V_{k1}^{i-T}& {\mathrm{\&Delta;V}}_{k2}^i=V_{k2}^i-V_{k2}^{i-T}\end{array}$

The first and last terminal voltage phase angle difference of k bar interconnection on the i moment and i-T described transmission cross-section of the moment after fault

with

be respectively:

$\begin{array}{cc}{\mathrm{\&delta;}}_k^i={\mathrm{\&delta;}}_{k1}^i-{\mathrm{\&delta;}}_{k2}^i& {\mathrm{\&delta;}}_k^{i-T}={\mathrm{\&delta;}}_{k1}^{i-T}-{\mathrm{\&delta;}}_{k2}^{i-T}\end{array}$

The i variable quantity of the first and last terminal voltage phase angle difference of k bar interconnection on described transmission cross-section constantly after fault

for:

${\mathrm{\&Delta;\&delta;}}_k^i={\mathrm{\&delta;}}_k^i-{\mathrm{\&delta;}}_k^{i-T}$

I energy reflection constantly system is dominated the leading system variable of Failure Model

with be respectively:

${\mathrm{\&Delta;P}}_{\mathrm{k\&delta;}}^i=\frac{V_{k1}^i{V}_{k2}^i}{\left|Z_k\right|}\cos ({\mathrm{\&delta;}}_k^i-\mathrm{\&alpha;})\&CenterDot;{\mathrm{\&Delta;\&delta;}}_k^i$

${\mathrm{\&Delta;P}}_{\mathrm{kv}}^i=(\frac{{2V}_{k1}^i}{\left|Z_k\right|}\sin \mathrm{\&alpha;}+\frac{V_{k2}^i}{\left|Z_k\right|}\sin ({\mathrm{\&delta;}}_k^i-\mathrm{\&alpha;}))\&CenterDot;{\mathrm{\&Delta;V}}_{k1}^i+\frac{V_{k1}^i}{\left|Z_k\right|}\&CenterDot;\sin ({\mathrm{\&delta;}}_k^i-\mathrm{\&alpha;})\&CenterDot;{\mathrm{\&Delta;V}}_{k2}^i$

Step S4': according to calculating resulting leading system variable, calculate leading Failure Model distinguishing indexes S, computing method are:

$S=\frac{|{\mathrm{\&Delta;P}}_{\mathrm{k\&delta;}}^i-{\mathrm{\&Delta;P}}_{\mathrm{ek}}^i|}{|{\mathrm{\&Delta;P}}_{\mathrm{k\&delta;}}^i-{\mathrm{\&Delta;P}}_{\mathrm{ek}}^i|+|{\mathrm{\&Delta;P}}_{\mathrm{kv}}^i-{\mathrm{\&Delta;P}}_{\mathrm{ek}}^i|}$

Index calculated value is as shown in table 1

Step S5': according to leading Failure Model distinguishing indexes S, the leading Failure Model of judgement system: when

time, merit angle unstability is taken Failure Model as the leading factor; When

time, Voltage Instability is taken Failure Model as the leading factor; When

time, now two kinds of components are in critical conditions, and the leading Failure Model None-identified of system, need to wait until that next judges constantly.The result of calculation of the leading Failure Model distinguishing indexes S that this example provides is as shown in table 1:

Table 1 index S result of calculation

According to result of calculation shown in table 1, index S is less than 0.5, and the leading Failure Model that can judge system is merit angle unstability, so system need take to cut machine measure.Supposing the system excises the generator at B2 place when 0.30s, and as shown in Figure 7, Figure 8, known to take to cut machine measure effective for the power-angle curve of system and voltage curve, and system is final recovers stable.

Finally should be noted that: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit; in conjunction with above-described embodiment, the present invention is had been described in detail; those of ordinary skill in the field are to be understood that: those skilled in the art carries out according to this concrete technical scheme is variously equal to, deformation process, also within protection scope of the present invention.

Claims (8)

1. the leading Failure Model recognition methods of the electric system based on actual measurement response message, the leading Failure Model of judgement multimachine interconnected electric power system after fault, is characterized in that, described method comprises:

Step S1, the information of measuring by WAMS measurement system is determined the transmission cross-section of described multimachine interconnected electric power system after fault;

Step S2, the T of take periodically obtains the transmission cross-section dynamic feature information that can reflect described multimachine interconnected electric power system dynamic perfromance as the sampling period by described WAMS measurement system;

Step S3, according to described transmission cross-section characteristic information, calculates two kinds of leading system variables of the leading Failure Model of energy reflection system;

Step S4, according to described leading system variable, calculates leading Failure Model distinguishing indexes S;

Step S5, according to described leading Failure Model distinguishing indexes S, judges whether two kinds of leading system variables equate, are, leading Failure Model None-identified, execution step S6; No, judging leading Failure Model is merit angle unstability or Voltage Instability;

Step S6, when judging that described multimachine interconnected electric power system is after fault during leading Failure Model constantly of i, the value that i is set is i=i+T, execution step S1.

2. the method for claim 1, is characterized in that, in described step S1, when the information of measuring by WAMS measurement system is determined the transmission cross-section of described multimachine interconnected electric power system after fault, transmission cross-section is losing synchronous sending between receiving-end system.

3. method as claimed in claim 2, it is characterized in that, in described step S2, the information of measuring according to WAMS measurement system is determined the interconnection that the transmission cross-section of described multimachine interconnected electric power system comprises after fault, when interconnection has many, the information on unstability interconnection of getting is as transmission cross-section dynamic feature information.

4. the method as described in claim 1 or 3, is characterized in that, described transmission cross-section dynamic feature information comprises not active power, interconnection first and last terminal voltage amplitude and the phase angle of unstability interconnection on transmission cross-section in the same time; Wherein, after fault, on i moment transmission cross-section, the active power of k bar interconnection is

interconnection first and last terminal voltage amplitude is respectively

interconnection first and last terminal voltage phase angle is respectively

5. the method for claim 1, it is characterized in that, in described step S2, from fault, start periodically to obtain the transmission cross-section dynamic feature information that can reflect described multimachine interconnected electric power system dynamic perfromance by described WAMS measurement system, the sampling period T of described transmission cross-section dynamic feature information is identical with the sampling period of PMU measuring unit in described WAMS measurement system.

6. method as claimed in claim 4, is characterized in that, in described step S3, according to described transmission cross-section dynamic feature information, the method for the leading system variable of the leading Failure Model of calculating energy reflection system is as follows:

After fault, on the i moment and i-T described transmission cross-section of the moment, the active power of k bar interconnection is respectively with

the i active power variable quantity of k bar interconnection constantly

for:

${\mathrm{\&Delta;P}}_{\mathrm{ek}}^i=P_{\mathrm{ek}}^i-P_{\mathrm{ek}}^{i-T};$

After fault, on i described transmission cross-section of the moment, the first and last terminal voltage amplitude of k bar interconnection is respectively

with

after fault, on i-T described transmission cross-section of the moment, the first and last terminal voltage amplitude of k bar interconnection is respectively

with

i k bar interconnection first and last terminal voltage amplitude variable quantity constantly

with

be respectively:

$\begin{array}{cc}{\mathrm{\&Delta;V}}_{k1}^i=V_{k1}^i-V_{k1}^{i-T}& {\mathrm{\&Delta;V}}_{k2}^i=V_{k2}^i-V_{k2}^{i-T}\end{array}$

The first and last terminal voltage phase angle difference of k bar interconnection on the i moment and i-T described transmission cross-section of the moment after fault with

be respectively:

$\begin{array}{cc}{\mathrm{\&delta;}}_k^i={\mathrm{\&delta;}}_{k1}^i-{\mathrm{\&delta;}}_{k2}^i& {\mathrm{\&delta;}}_k^{i-T}={\mathrm{\&delta;}}_{k1}^{i-T}-{\mathrm{\&delta;}}_{k2}^{i-T}\end{array}$

The i variable quantity of the first and last terminal voltage phase angle difference of k bar interconnection on described transmission cross-section constantly after fault

for:

${\mathrm{\&Delta;\&delta;}}_k^i={\mathrm{\&delta;}}_k^i-{\mathrm{\&delta;}}_k^{i-T}$

I energy reflection constantly system is dominated the leading system variable of Failure Model

with

be respectively:

${\mathrm{\&Delta;P}}_{\mathrm{k\&delta;}}^i=\frac{V_{k1}^i{V}_{k2}^i}{\left|Z_k\right|}\cos ({\mathrm{\&delta;}}_k^i-\mathrm{\&alpha;})\&CenterDot;{\mathrm{\&Delta;\&delta;}}_k^i$

${\mathrm{\&Delta;P}}_{\mathrm{kv}}^i=(\frac{{2V}_{k1}^i}{\left|Z_k\right|}\sin \mathrm{\&alpha;}+\frac{V_{k2}^i}{\left|Z_k\right|}\sin ({\mathrm{\&delta;}}_k^i-\mathrm{\&alpha;}))\&CenterDot;{\mathrm{\&Delta;V}}_{k1}^i+\frac{V_{k1}^i}{\left|Z_k\right|}\&CenterDot;\sin ({\mathrm{\&delta;}}_k^i-\mathrm{\&alpha;})\&CenterDot;{\mathrm{\&Delta;V}}_{k2}^i$

Wherein, Z _kbe k bar interconnection line impedance, the complementary angle that α is angle of impedance, Z _k=R _Σ+ jX _Σ=| Z| ∠ arctgX _Σ/ R _Σ, α=pi/2-arctgX _Σ/ R _Σ.

7. method as claimed in claim 4, is characterized in that, in described step S4, according to calculating resulting leading system variable, the method for calculating leading Failure Model distinguishing indexes S is:

$S=\frac{|{\mathrm{\&Delta;P}}_{\mathrm{k\&delta;}}^i-{\mathrm{\&Delta;P}}_{\mathrm{ek}}^i|}{|{\mathrm{\&Delta;P}}_{\mathrm{k\&delta;}}^i-{\mathrm{\&Delta;P}}_{\mathrm{ek}}^i|+|{\mathrm{\&Delta;P}}_{\mathrm{kv}}^i-{\mathrm{\&Delta;P}}_{\mathrm{ek}}^i|}$

8. the method for claim 1, is characterized in that, in described step S5, according to leading Failure Model distinguishing indexes S, the leading Failure Model method of judgement system is:

When

time, merit angle unstability is taken Failure Model as the leading factor;

When

time, Voltage Instability is taken Failure Model as the leading factor;

When

time, now two kinds of leading system variables equate, and multimachine interconnected electric power system is in critical conditions, and the leading Failure Model None-identified of multimachine interconnected electric power system, waits until that next judges constantly.

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