CN104330671B - Evaluation and analysis method of alternating-current tie line power fluctuation caused by impulse disturbance - Google Patents

Abstract

The invention provides an evaluation and analysis method of alternating-current tie line power fluctuation caused by impulse disturbance. The evaluation and analysis method comprises the steps of obtaining the interregional oscillation frequency and the interregional damping ratio of the oscillation modes of the power grids on the two sides of a tie line, obtaining the ratio of the inertia constants of the power grids on the two sides of the tie line, determining the maximum power value and the equivalent impulse time of the impulse disturbance, determining the maximum value of the alternating-current tie line power fluctuation caused by the impulse disturbance and the time of obtaining the maximum value of the power fluctuation, and evaluating the influence of the impulse disturbance on the alternating-current tie line. The evaluation and analysis method of the alternating-current tie line power fluctuation caused by the impulse disturbance is applicable to analyzing the tie line fluctuation circumstances in cases of faults such as direct-current commutation failure and direct-current restart, and helpful for the system analysts and the dispatching operators to analyze the characteristics of the power grids.

Description

A kind of analysis and assessment method of the alternating current interconnection tie power fluctuation that impulse disturbance causes

Technical field

The present invention relates to a kind of analysis method, and in particular to the alternating current interconnection tie power fluctuation that a kind of impulse disturbance causes Analysis and assessment method.

Background technology

Due to china natural resources energy skewness, distance is longer between Energy Base and load center, and direct current transportation is at me State has obtained large-scale application, defines huge AC-DC interconnecting power network.In particular with extra-high voltage direct-current engineering Large scale construction, influencing each other between ac and dc systemses become apparent from, and commutation failure is wherein common one kind.Receiving end electricity Net AC fault will cause direct-current commutation failure, direct-current commutation failure that of short duration disturbance is produced to AC system, and disturbance may cause The fluctuation of alternating current interconnection.Because afterwards the commutation failure duration is shorter and it is normal to recover, itself is little to systematic influence.But The alternating current interconnection tie power fluctuation that commutation failure causes will produce considerable influence to the ability to transmit electricity of alternating current interconnection.Direct current is again Start and successfully there is also Similar Problems.Thus how accurately to calculate commutation failure, direct current and the friendship that impulse disturbance causes such as restart The fluctuation size of stream interconnection arranges significant to instructing actual interconnection mode.

The patent of invention of Application No. 201010187823.1 discloses a kind of two big regional internet electric power system alternating current connection The computational methods of winding thread tie power fluctuation peak, using 2 rank time-domain analysis in linear correlation techniques the ranks such as unit tripping are given The computational methods of jump disturbance initiation area interconnection fluctuating power size.But commutation failure, direct current are restarted successfully etc. rapid The impulse disturbance of recovery does not provide analysis to interconnection fluctuation size.And impulse disturbance causes the fluctuation mechanism and machine of interconnection The step disturbances such as group tripping operation, direct current locking cause interconnection fluctuation mechanism to there is larger difference.If directly adopting above-mentioned patent Result difference is very big when the method for offer calculates the interconnection fluctuation size of impulse disturbance initiation.

The content of the invention

In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides the alternating current interconnection power that a kind of impulse disturbance causes The analysis and assessment method of fluctuation, it is adaptable to direct-current commutation failure, direct current occur and the interconnection fluctuation situation point under failure such as restarts Analysis, is conducive to systems analyst, management and running personnel analysis electrical network characteristic.

In order to realize foregoing invention purpose, the present invention is adopted the following technical scheme that：

The present invention provides a kind of analysis and assessment method of the alternating current interconnection tie power fluctuation that impulse disturbance causes, methods described Comprise the following steps：

Step 1：Obtain the inter area oscillation frequency and interregional damping ratio of interconnection both sides power grid oscillation mode；

Step 2：Obtain the ratio of the inertia constant of alternating current interconnection both sides electrical network；

Step 3：Determine the maximum power value of impulse disturbance and equivalent impulse time；

Step 4：Determine the alternating current interconnection tie power fluctuation maximum of impulse disturbance initiation and obtain power swing maximum Time；

Step 5：Impact of the assessment impulse disturbance to alternating current interconnection.

In the step 1, the eigenvalue Method in the analysis of little interference theory obtains the electrical network vibration of interconnection both sides The inter area oscillation frequency and interregional damping ratio of pattern, or interconnection actual power oscillating curve is carried out during to disturbing PRONY analyses obtain the inter area oscillation frequency and interregional damping ratio of interconnection both sides power grid oscillation mode, inter area oscillation Frequency and interregional damping ratio use respectively ω_dRepresent with ξ.

In the step 2, according to the generator parameter of interconnection both sides electrical network, the inertia for obtaining interconnection both sides electrical network is normal Several ratio, uses H_Σ1/H_Σ2Represent, wherein H_Σ1、H_Σ2Respectively total inertia constant of all units of interconnection both sides electrical network.

In the step 3, situation is disturbed according to impulse, obtain the maximum power value of impulse disturbance, use Δ P_maxRepresent；

The equivalent impulse time of impulse disturbance represents have with Δ T：

Wherein, Δ P and t are respectively impulse disturbance instantaneous value and duration.

In the step 4, according to the response characteristic of the lower second-order system of of short duration square wave disturbance, you can determine that impulse disturbance causes Alternating current interconnection tie power fluctuation maximum and obtain power swing maximum time.

The step 4 is comprised the following steps：

(4-1) because square wave disturbance can be analyzed to positive step disturbance and negative sense step disturbance, received according to alternating current interconnection The wave equation of step disturbance, obtains the wave equation of its recipient's wave disturbance：

Wherein, h (t) for alternating current interconnection recipient's wave disturbance wave function, Δ P_sSize is disturbed for square wave, Δ t is side The wave disturbance time；H_Σ1And H_Σ2Respectively total inertia constant of all units of interconnection both sides electrical network, ξ is interregional damping ratio, ω_nFor natural frequency of oscillation, ω_dFor inter area oscillation frequency, β is initial phase angle；

Because Δ T is much smaller than the inter area oscillation cycle and ξ is less than 0.15,1 is approximately, then formula (1) is reduced to：

Because the impulse time is much smaller than the inter area oscillation cycle, formula (2) can be reduced to：

Multiple square wave disturbance superpositions constitute impulse disturbance, ignore the decay between each square-wave response and phase difference, according to Formula (3) can obtain the wave equation of the alternating current interconnection that impulse disturbance causes：

Wherein, H (t) disturbs the wave function of the alternating current interconnection for causing, Δ P for impulse_maxFor the maximum work of impulse disturbance Rate value, is the equivalent impulse time of Δ T impulses disturbance；

(4-2) wave equation of the alternating current interconnection for causing, the alternating current interconnection that impulse disturbance causes are disturbed according to impulse The time of power swing maximum and acquirement power swing maximum is expressed as：

Wherein, H_maxThe alternating current interconnection tie power fluctuation maximum for causing, t are disturbed for impulse_pThe friendship for causing is disturbed for impulse Stream interconnection obtains the time of power swing maximum.

In the step 5, according to the alternating current interconnection tie power fluctuation maximum and acquirement work(of the impulse disturbance initiation for obtaining The time assessment impulse of rate fluctuation maximum disturbs the impact to alternating current interconnection, the alternating current interconnection power that impulse disturbance causes Fluctuation maximum is bigger, and the impact that impulse is disturbed to alternating current interconnection is bigger.

Compared with prior art, the beneficial effects of the present invention is：

The present invention is by obtaining the alternating current interconnection tie power fluctuation maximum and obtain power swing most that impulse disturbance causes The time of big value, assess impact of the impulse disturbance to alternating current interconnection.Suitable for the punching such as restarting to direct-current commutation failure, direct current The interconnection fluctuation situation that sharp failure causes fast and accurately is analyzed, and is that interconnection mode arranges to be carried with control measure formulation For foundation, be conducive to systems analyst, management and running personnel analysis electrical network characteristic.

Description of the drawings

Fig. 1 is the analysis and assessment method flow of the alternating current interconnection tie power fluctuation that impulse disturbance causes in the embodiment of the present invention Figure；

Fig. 2 is that Central China Power Grid sends dc power waveform when direct current gives again direct current generation commutation failure outside in the embodiment of the present invention Figure；

Fig. 3 be the perturbation waveform figure of Central China during commutation failure in the embodiment of the present invention-North China contact line length south I lines ( Deduct initial power).

Specific embodiment

The present invention is described in further detail below in conjunction with the accompanying drawings.

Such as the analysis and assessment method of the alternating current interconnection tie power fluctuation that Fig. 1, a kind of impulse disturbance of present invention offer cause, institute The method of stating is comprised the following steps：

Step 1：Obtain the inter area oscillation frequency and interregional damping ratio of interconnection both sides power grid oscillation mode；

Step 2：Obtain the ratio of the inertia constant of alternating current interconnection both sides electrical network；

Step 3：Determine the maximum power value of impulse disturbance and equivalent impulse time；

Step 4：Determine the alternating current interconnection tie power fluctuation maximum of impulse disturbance initiation and obtain power swing maximum Time；

Step 5：Impact of the assessment impulse disturbance to alternating current interconnection.

In the step 1, the eigenvalue Method in the analysis of little interference theory obtains the electrical network vibration of interconnection both sides The inter area oscillation frequency and interregional damping ratio of pattern, or interconnection actual power oscillating curve is carried out during to disturbing PRONY analyses obtain the inter area oscillation frequency and interregional damping ratio of interconnection both sides power grid oscillation mode, inter area oscillation Frequency and interregional damping ratio use respectively ω_dRepresent with ξ.

In the step 2, according to the generator parameter of interconnection both sides electrical network, the inertia for obtaining interconnection both sides electrical network is normal Several ratio, uses H_Σ1/H_Σ2Represent, wherein H_Σ1、H_Σ2Respectively total inertia constant of all units of interconnection both sides electrical network.

In the step 3, situation is disturbed according to impulse, obtain the maximum power value of impulse disturbance, use Δ P_maxRepresent；

The equivalent impulse time of impulse disturbance represents have with Δ T：

Wherein, Δ P and t are respectively impulse disturbance instantaneous value and duration.

In the step 4, according to the response characteristic of the lower second-order system of of short duration square wave disturbance, you can determine that impulse disturbance causes Alternating current interconnection tie power fluctuation maximum and obtain power swing maximum time.

The step 4 is comprised the following steps：

(4-1) because square wave disturbance can be analyzed to positive step disturbance and negative sense step disturbance, received according to alternating current interconnection The wave equation of step disturbance, obtains the wave equation of its recipient's wave disturbance：

Wherein, h (t) for alternating current interconnection recipient's wave disturbance wave function, Δ P_sSize is disturbed for square wave, Δ t is side The wave disturbance time；H_Σ1And H_Σ2Respectively total inertia constant of all units of interconnection both sides electrical network, ξ is interregional damping ratio, ω_nFor natural frequency of oscillation, ω_dFor inter area oscillation frequency, β is initial phase angle；

Because Δ T is much smaller than the inter area oscillation cycle and ξ is less than 0.15,1 is approximately, then formula (1) is reduced to：

Because the impulse time is much smaller than the inter area oscillation cycle, formula (2) can be reduced to：

Multiple square wave disturbance superpositions constitute impulse disturbance, ignore the decay between each square-wave response and phase difference, according to Formula (3) can obtain the wave equation of the alternating current interconnection that impulse disturbance causes：

Wherein, H (t) disturbs the wave function of the alternating current interconnection for causing, Δ P for impulse_maxFor the maximum work of impulse disturbance Rate value, is the equivalent impulse time of Δ T impulses disturbance；

(4-2) wave equation of the alternating current interconnection for causing, the alternating current interconnection that impulse disturbance causes are disturbed according to impulse The time of power swing maximum and acquirement power swing maximum is expressed as：

Wherein, H_maxThe alternating current interconnection tie power fluctuation maximum for causing, t are disturbed for impulse_pThe friendship for causing is disturbed for impulse Stream interconnection obtains the time of power swing maximum.

In the step 5, according to the alternating current interconnection tie power fluctuation maximum and acquirement work(of the impulse disturbance initiation for obtaining The time assessment impulse of rate fluctuation maximum disturbs the impact to alternating current interconnection, the alternating current interconnection power that impulse disturbance causes Fluctuation maximum is bigger, and the impact that impulse is disturbed to alternating current interconnection is bigger.To prevent alternating current interconnection peak power from reaching line Road stability limit, alternating current interconnection actual power is less than the friendship that circuit stability limitation and impulse disturbance cause when arranging normal operation The difference of stream interconnection tie power fluctuation maximum.

Embodiment

When Central China or North China direct current occur commutation failure, straight-flow system applies an impulse disturbance to AC network, in punching Central China-North China contact line length south I linear heat generation rates can fluctuate under sharp perturbation action.Send East China extra-high straightening with actual certain Central China Stream gives again the correctness that Central China when direct current occurs commutation failure-North China contact line length south I line fluctuations size verifies this method.

(1) interconnection actual power oscillating curve can obtain Central China North China when analyzing or disturb according to little interference theory Frequency of oscillation is 0.183Hz between electrical network, and damping ratio is 0.081；

(2) according to the generator parameter of interconnection both sides electrical network, the ratio 0.67 of the inertia constant of two electrical networks can be obtained:1；

(3) according to commutation failure waveform, 5,400,000 kilowatts of the maximum impulse power for disturbing, equivalent impulse time can be obtained 0.14 second；

(4) adopt the inventive method to calculate interconnection maximum fluctuation value for 460,000 kilowatts, obtain the maximum fluctuation value time For 1.43 seconds, I line maximum fluctuations value in actual (tube) length south was 510,000 kilowatts, obtains 1.7 seconds maximum fluctuation value time, and both basic one Cause, demonstrate the correctness of this method.According to entitled " two big regional internet electric power system alternating current interconnection tie power fluctuation peaks Method in the patent of the computational methods of value " calculates maximum fluctuation value for 5,740,000 kilowatts, obtains the maximum fluctuation value time and is It is 2.73 seconds, very big with actual fluctuation situation difference.Illustrate that the method that patent of the present invention is provided is applied to the connection that impulse disturbs initiation Winding thread fluctuation size is calculated；And entitled " the calculating side of two big regional internet electric power system alternating current interconnection tie power fluctuation peaks The interconnection fluctuation that the method and inapplicable impulse disturbance that the patent of method " is proposed causes is calculated, and is only applicable to step disturbance initiation Interconnection fluctuation calculate.Can be according to interconnection fluctuation maximum and interconnection stability limitation reasonable arrangement interconnection conveying work( Rate.

Finally it should be noted that：Above example only to illustrate technical scheme rather than a limitation, institute The those of ordinary skill in category field with reference to above-described embodiment still can to the present invention specific embodiment modify or Equivalent, these any modifications or equivalent without departing from spirit and scope of the invention are applying for pending this Within bright claims.

Claims (6)

1. a kind of impulse disturbs the analysis and assessment method of the alternating current interconnection tie power fluctuation for causing, it is characterised in that：Methods described Comprise the following steps：

Step 1：Obtain the inter area oscillation frequency and interregional damping ratio of interconnection both sides power grid oscillation mode；

Step 2：Obtain the ratio of the inertia constant of alternating current interconnection both sides electrical network；

Step 3：Determine the maximum power value of impulse disturbance and equivalent impulse time；

Step 4：Determine impulse disturbance cause alternating current interconnection tie power fluctuation maximum and obtain power swing maximum when Between；

Step 5：Impact of the assessment impulse disturbance to alternating current interconnection；

The step 4 is comprised the following steps：

(4-1) because square wave disturbance can be analyzed to positive step disturbance and negative sense step disturbance, step is received according to alternating current interconnection The wave equation of disturbance, obtains the wave equation of its recipient's wave disturbance：

$\begin{array}{c}h\left(t\right)={\mathrm{\ΔP}}_s\frac{H_{\mathrm{\Σ}2}}{H_{\mathrm{\Σ}1}+H_{\mathrm{\Σ}2}}\left(1-\frac{1}{\sqrt{1-{\mathrm{\ξ}}^2}}{e}^{-{\mathrm{\ξ\ω}}_{n}t}\sin \left({\mathrm{\ω}}_{d}t+\mathrm{\β}\right)\right)\\ -{\mathrm{\ΔP}}_s\frac{H_{\mathrm{\Σ}2}}{H_{\mathrm{\Σ}1}+H_{\mathrm{\Σ}2}}\left(1-\frac{1}{\sqrt{1-{\mathrm{\ξ}}^2}}{e}^{-{\mathrm{\ξ\ω}}_n\left(t-\mathrm{\Δ}t\right)}\sin \left({\mathrm{\ω}}_d\left(t-\mathrm{\Δ}t\right)+\mathrm{\β}\right)\right)\end{array}---\left(1\right)$

Wherein, h (t) for alternating current interconnection recipient's wave disturbance wave function, Δ P_sSize is disturbed for square wave, Δ t is square wave disturbance Time；H_Σ1And H_Σ2Respectively total inertia constant of all units of interconnection both sides electrical network, ξ is interregional damping ratio, ω_nIt is certainly Right frequency of oscillation, ω_dFor inter area oscillation frequency, β is initial phase angle；

Because Δ t is much smaller than the inter area oscillation cycle and ξ is less than 0.15,1 is approximately, then formula (1) is reduced to：

$h\left(t\right)\≈{\mathrm{\ΔP}}_s\frac{H_{\mathrm{\Σ}2}}{H_{\mathrm{\Σ}1}+H_{\mathrm{\Σ}2}}\frac{1}{\sqrt{1-{\mathrm{\ξ}}^2}}{e}^{-{\mathrm{\ξ\ω}}_n(t-\frac{\mathrm{\Δ}t}{2})}\·2sin\left(\frac{{\mathrm{\ω}}_d\mathrm{\Δ}t}{2}\right)sin\left({\mathrm{\ω}}_d\right(t-\frac{\mathrm{\Δ}t}{2})+\mathrm{\β}-\frac{\mathrm{\π}}{2})---\left(2\right)$

Because the impulse time is much smaller than the inter area oscillation cycle, formula (2) can be reduced to：

$h\left(t\right)\≈{\mathrm{\ΔP}}_s{\mathrm{\ω}}_d\mathrm{\Δ}t\frac{H_{\mathrm{\Σ}2}}{H_{\mathrm{\Σ}1}+H_{\mathrm{\Σ}2}}\frac{1}{\sqrt{1-{\mathrm{\ξ}}^2}}{e}^{-{\mathrm{\ξ\ω}}_n\left(t-\frac{\mathrm{\Δ}t}{2}\right)}\sin \left({\mathrm{\ω}}_d\left(t-\frac{\mathrm{\Δ}t}{2}\right)+\mathrm{\β}-\frac{\mathrm{\π}}{2}\right)---\left(3\right)$

Multiple square wave disturbance superpositions constitute impulse disturbance, ignore the decay between each square-wave response and phase difference, according to formula (3) The wave equation of the alternating current interconnection that impulse disturbance causes can be obtained：

$\begin{array}{c}H\left(t\right)\≈\underset{t=0}{\overset{t}{\∫}}\mathrm{\Δ}Pdt\·{\mathrm{\ω}}_d\frac{H_{\mathrm{\Σ}2}}{H_{\mathrm{\Σ}1}+H_{\mathrm{\Σ}2}}\frac{1}{\sqrt{1-{\mathrm{\ξ}}^2}}{e}^{-{\mathrm{\ξ\ω}}_n\left(t-\frac{\mathrm{\Δ}T}{2}\right)}\sin \left({\mathrm{\ω}}_d\left(t-\frac{\mathrm{\Δ}T}{2}\right)+\mathrm{\β}-\frac{\mathrm{\π}}{2}\right)\\ ={\mathrm{\ΔP}}_{\max }{\mathrm{\ΔT\ω}}_d\frac{H_{\mathrm{\Σ}2}}{H_{\mathrm{\Σ}1}+H_{\mathrm{\Σ}2}}\frac{1}{\sqrt{1-{\mathrm{\ξ}}^2}}{e}^{-{\mathrm{\ξ\ω}}_n\left(t-\frac{\mathrm{\Δ}T}{2}\right)}\sin \left({\mathrm{\ω}}_d\left(t-\frac{\mathrm{\Δ}T}{2}\right)+\mathrm{\β}-\frac{\mathrm{\π}}{2}\right)\end{array}---\left(4\right)$

Wherein, Δ P is that impulse disturbs instantaneous value, and H (t) disturbs the wave function of the alternating current interconnection for causing, Δ P for impulse_maxFor The maximum power value of impulse disturbance, Δ T is the equivalent impulse time of impulse disturbance；

(4-2) wave equation of the alternating current interconnection for causing, the alternating current interconnection power that impulse disturbance causes are disturbed according to impulse The time of fluctuation maximum and acquirement power swing maximum is expressed as：

$H_{max}\≈{\mathrm{\ΔP}}_{max}{\mathrm{\ΔT\ω}}_d\frac{H_{\mathrm{\Σ}2}}{H_{\mathrm{\Σ}1}+H_{\mathrm{\Σ}2}}{e}^{-\mathrm{\ξ}\mathrm{\π}/2\sqrt{1-{\mathrm{\ξ}}^2}}---\left(5\right)$

$t_p=\frac{\mathrm{\π}}{2{\mathrm{\ω}}_d}+\frac{\mathrm{\Δ}T}{2}---\left(6\right)$

Wherein, H_maxThe alternating current interconnection tie power fluctuation maximum for causing, t are disturbed for impulse_pThe exchange for causing connection is disturbed for impulse Winding thread obtains the time of power swing maximum.

2. impulse according to claim 1 disturbs the analysis and assessment method of the alternating current interconnection tie power fluctuation for causing, and it is special Levy and be：In the step 1, the eigenvalue Method in the analysis of little interference theory obtains interconnection both sides electrical network oscillation mode The inter area oscillation frequency and interregional damping ratio of formula, or interconnection actual power oscillating curve is carried out during to disturbing PRONY analyses obtain the inter area oscillation frequency and interregional damping ratio of interconnection both sides power grid oscillation mode, inter area oscillation Frequency and interregional damping ratio use respectively ω_dRepresent with ξ.

3. impulse according to claim 1 disturbs the analysis and assessment method of the alternating current interconnection tie power fluctuation for causing, and it is special Levy and be：In the step 2, according to the generator parameter of interconnection both sides electrical network, the inertia for obtaining interconnection both sides electrical network is normal Several ratio, uses H_Σ1/H_Σ2Represent, wherein H_Σ1、H_Σ2Respectively total inertia constant of all units of interconnection both sides electrical network.

4. impulse according to claim 1 disturbs the analysis and assessment method of the alternating current interconnection tie power fluctuation for causing, and it is special Levy and be：In the step 3, situation is disturbed according to impulse, obtain the maximum power value of impulse disturbance, use Δ P_maxRepresent；

The equivalent impulse time of impulse disturbance represents have with Δ T：

$\mathrm{\Δ}T=\underset{t=0}{\overset{t}{\∫}}\mathrm{\Δ}Pdt\backslash {\mathrm{\ΔP}}_{max}$

Wherein, Δ P and t are respectively impulse disturbance instantaneous value and duration.

5. impulse according to claim 1 disturbs the analysis and assessment method of the alternating current interconnection tie power fluctuation for causing, and it is special Levy and be：In the step 4, according to the response characteristic of the lower second-order system of of short duration square wave disturbance, you can determine that impulse disturbance causes Alternating current interconnection tie power fluctuation maximum and obtain power swing maximum time.

6. impulse according to claim 1 disturbs the analysis and assessment method of the alternating current interconnection tie power fluctuation for causing, and it is special Levy and be：In the step 5, according to the alternating current interconnection tie power fluctuation maximum and acquirement power of the impulse disturbance initiation for obtaining The time assessment impulse of fluctuation maximum disturbs the impact to alternating current interconnection, the alternating current interconnection power waves that impulse disturbance causes Dynamic maximum is bigger, and the impact that impulse is disturbed to alternating current interconnection is bigger.