CN104484746A - Interconnected power grid running control performance evaluation system - Google Patents

Abstract

The embodiment of the invention provides an interconnected power grid running control performance evaluation system. The system comprises a setting module, an acquiring module, a calculating module and an evaluating module, wherein the setting module is used for setting parameters of the system; the acquiring module is used for acquiring the frequency of a power grid and power deviation of a power grid connecting wire; the calculating module is used for calculating the frequency deviation and area control deviation of the power grid; the evaluating module is used for evaluating the running control performance of a regional power grid according to the parameters of the system, the frequency of the power grid, the frequency deviation of the power grid, the power deviation of the power grid connecting wire and the area control deviation. The interconnected power grid running control performance evaluation system disclosed by the invention realizes evaluation on the running control performance of the regional power grid aiming at different time scales, solves the problem of frequent regulation and excessive regulation occurring in running control on each regional power grid in the prior art, and improves the running control efficiency of the power grid.

Description

Interconnected network runs control performance evaluation system

Technical field

The embodiment of the present invention relates to interconnected network technical field, particularly relates to a kind of interconnected network and runs control performance evaluation system.

Background technology

China's electrical network starts to adopt A standard mid-term in last century 80.Calendar year 2001, use for reference North America CPS standard, East China and Fujian Electric Power Network have carried out new evaluation criterion and relevant evaluation method.Subsequently, Central China Power Grid and Southern Power Grid Company also release one after another oneself evaluation criterion and relevant evaluation method.Although China's second generation standard is identical with North-America standard index number, because index structural form exists different, therefore its intension and North-America standard there are differences.Therefore, the framework of two cover standards is not quite similar.

North American power grid CPS standard is made up of CPS1 and CPS2 two standards.Wherein CPS1 by form in the rolling of a year average (year rolls average), therefore it pays close attention to is the performance of (as: in a year) in a long period section of frequency difference sequence, and CPS2 is made up of the average of control deviation in 10 minutes, for limiting the inadvertent exchange electric quantity between control area under any method of operation.

China's electrical network evaluation criterion is also be made up of CPS1 and CPS2 two standards.Because its CPS1 is by first 10 minutes of Evaluation: Current point mean value (10 minute period is average) form, therefore its pay close attention to be frequency difference sequence in current 10 minutes sections short-term performance; And CPS2 is made up of the average of control deviation in 10 minutes, it is combined with CPS1, is making the inadvertent exchange electric quantity be unfavorable under system frequency recovery control situation by relevant evaluation method for limiting between control area.

For north American power grid, because its frequency quality meets the demands, therefore the target of its evaluation criterion stresses guidance system to control, and under the prerequisite not reducing system cloud gray model frequency quality, makes operation of power networks more economical.Therefore, in CPS1 standard, adjustment target is the frequency difference root mean square of the previous year, as long as mean the level that regulating effect reaches the previous year; And the year rolling average design in index, object to make control area make amends for one's faults by good deeds, and makes full use of the advantage of regional internet, to save adjustment cost.Therefore, for north American power grid, existing CPS framework enough meets frequency control requirement, and operative practice also demonstrates this point.

In China, because frequency security problem is never effectively solved, therefore, the emphasis of dispatching of power netwoks is short time interval frequency control.Therefore roll that to be on average revised as 10 minute period average year in being designed by CPS1 standard index in the standard carried out.Facts have proved, this way gets a desired effect to a certain extent, but there is following problem: one, because regulation in evaluation method carries out economic rewards and punishments according to CPS1 qualification rate, therefore qualified rate rank is pursued for reducing fine in each control area, the index contest between control area can be developed into, cause and excessively regulate and be unfavorable for energy-saving and emission-reduction.Two, in the formulation of AGC control, if according to long-time statistical index (as 1 year CPS1 qualification rate), then because such index relates to human factor, there is no fixed target, probably cause and control situation at a loss as to what to do; And if according to short run target (as CPS1 index itself), if system cloud gray model frequency variation is frequent, then pursuing for improving index the control that in 10 minutes, control deviation and frequency difference opposite sign are made, the number of times of control deviation zero passage can be made than also many during employing A standard.

Summary of the invention

The embodiment of the present invention provides a kind of interconnected network to run control performance evaluation system, to overcome the problem that is frequent and that excessively regulate of interconnected network running frequency variation in prior art.

Embodiments provide a kind of interconnected network and run control performance evaluation system, comprising:

Setting module, for the parameter of initialization system;

Acquisition module, for gathering mains frequency, interconnecting ties power deviation;

Computing module, for calculating mains frequency deviation, district control deviation;

Evaluation module, for according to described system parameter, described mains frequency, described mains frequency deviation, described interconnecting ties power deviation and described district control deviation, for different time scale evaluation region operation of power networks control performances.

Further, described setting module, specifically for:

Initialization system frequency security frequency difference limit value Δ f _d, field frequency Z-factor B _i, evaluate period T;

Described computing module, specifically for:

Adopt formula (1)

L _di＝-10B _iΔf _d(1)

The control deviation limit value of zoning;

Described evaluation module, specifically for:

Adopt formula (2)

$I_{\mathrm{fv}}=\left\{\underset{j\∈T}{\mathrm{\Σ}}\right\{\mathrm{sign}\left(\stackrel{\‾}{{\mathrm{\Δf}}_j}\right)\×[\mathrm{sign}\left(\stackrel{\‾}{{\mathrm{\Δf}}_j}\right)\×L_{\mathrm{di}}-{\mathrm{ACE}}_{\mathrm{ij}}]\left\}\right\}{|}_{\left|\stackrel{\‾}{{\mathrm{\Δf}}_j}\right|>{\mathrm{\Δf}}_d}---\left(2\right)$

Zoning frequency security index, if I _fv>=0, then examine the frequency security qualified in region, wherein, described i is control area; Described T, for evaluating the period, can be 1 year, month or week etc.; Described j ∈ T evaluates the time point in period T, is spaced apart every 5 seconds one; Described L _difor the district control deviation limit value of control area i, unit MW; Described B _ifor the frequency bias coefficient that control area i is assigned with, be negative, unit MW/0.1Hz; Described for the average in 5 seconds before the system frequency difference of j time point, unit Hz, frequency difference is 1 sampled value per second; Described Δ f _dfor system frequency difference limit value, unit Hz; Described ACE _ijfor control area i is at the district control deviation of j time point, every 5 seconds 1 sampled values; Described sign is sign function, and its numerical value is

$\mathrm{sign}\left(x\right)=\left\{\begin{array}{c}1,x>0\\ 0,x=0\\ -1,x<0\end{array}\right..$

Further, described setting module, specifically for:

Initialization system inadvertent exchange electric quantity limit value L _ti, evaluate period T;

Described evaluation module, specifically for:

Adopt formula (3)

Zoning frequency security index, if I _electricitywhen≤1, the control in region meets frequency security requirement, wherein, and described L _tifor inadvertent exchange electric quantity limit in the evaluation period t that control area i is prescribed, unit is MW, can make adjustment with running status or for customization, described in for control area i is in the average evaluating period t inner region control deviation, unit is MW.

Further, described setting module, specifically for:

Initialization system frequency quality criteria frequency difference limit value ε ₁, evaluate period T, region difference coefficient B;

Described evaluation module, specifically for:

Adopt formula (4) and (5)

${\mathrm{CF}}_1=\frac{1}{{\mathrm{\&epsiv;}}_1^2}\stackrel{\&OverBar;}{{\left\{\frac{\mathrm{ACE}}{-10B}\right\}}_1}\&times;{\stackrel{\&OverBar;}{\mathrm{\&Delta;f}}}_1---\left(4\right)$

I _quality=(2-AVG _t{ CF ₁) × 100% (5)

Zoning frequency quality index, if I _quality>=100%, then qualified by examination field frequency quality index, wherein, described AVG _tfor the mean value in the T period, described Δ f ₁for the system frequency difference mean value of 1 minute, unit is Hz, described B is examined the frequency bias coefficient in region, for negative, unit is MW/0.1Hz, and described control deviation is examined the district control deviation in region, unit is MW, described T is for evaluating the period, and unit is the moon, i.e. the historical data of the previous moon of the calculating use of each examination value.

Further, also comprise:

Memory module, for preserving mains frequency, interconnecting ties power deviation that described acquisition module gathers.

The embodiment of the present invention, evaluation module is according to setting module initialization system parameter, mains frequency, interconnecting ties power deviation that acquisition module gathers, computing module calculates mains frequency deviation, district control deviation, evaluates operation of power networks control performance for different time scales.Thus achieve evaluation region operation of power networks control performance under full time scale, solve each regional power grid in prior art and run the frequent adjustment controlling to occur in enforcement and the problem excessively regulated, improve operation of power networks control efficiency.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, introduce doing one to the accompanying drawing used required in embodiment or description of the prior art simply below, apparently, accompanying drawing in the following describes is some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Fig. 1 is that interconnected network of the present invention runs control performance evaluation system structural representation;

Fig. 2 is that interconnected network of the present invention runs another structural representation of control performance evaluation system.

Embodiment

For making the object of the embodiment of the present invention, technical scheme and advantage clearly, below in conjunction with the accompanying drawing in the embodiment of the present invention, technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

Fig. 1 is that interconnected network of the present invention runs control performance evaluation system structural representation, and as shown in Figure 1, the system of the present embodiment can comprise:

Setting module 101, parameter for initialization system;

Acquisition module 102, for gathering mains frequency, interconnecting ties power deviation;

Specifically, interconnecting ties power deviation is Δ P _t=P _t– P _s, wherein, Δ P _tfor interconnecting ties power deviation, P _sfor interconnection unscheduled power, P _tfor interconnection real power.

Computing module 103, for calculating mains frequency deviation, district control deviation;

Specifically, mains frequency deviation delta f=f – 50, wherein, Δ f is mains frequency deviation, and f is mains frequency.District control deviation is ACE=Δ P _t– 10B _iΔ f, wherein, ACE is district control deviation, B _ifor the frequency bias coefficient that control area i is assigned with, be negative, unit is MW/0.1Hz.In the present embodiment, at interval of 5 seconds, acquisition module gathers mains frequency, interconnecting ties power deviation, and computing module calculates mains frequency deviation, district control deviation ACE.

Evaluation module 104, for according to described system parameter, described mains frequency, described mains frequency deviation, described interconnecting ties power deviation and described district control deviation, evaluate operation of power networks control performance for different time scales.

Specifically, at each evaluation period T end, evaluation module, according to system parameter, mains frequency, mains frequency deviation, interconnecting ties power deviation and district control deviation, evaluates operation of power networks control performance at Different time scales.This evaluation period T by setting module according to system parameter settings.

Further, described setting module, specifically for:

Initialization system frequency security frequency difference limit value Δ f _d, field frequency Z-factor B _i, evaluate period T;

Described computing module, specifically for:

Adopt formula (1)

L _di＝-10B _iΔf _d(1)

The control deviation limit value of zoning;

Described evaluation module, specifically for:

Adopt formula (2)

$I_{\mathrm{fv}}=\left\{\underset{j\&Element;T}{\mathrm{\&Sigma;}}\right\{\mathrm{sign}\left(\stackrel{\&OverBar;}{{\mathrm{\&Delta;f}}_j}\right)\&times;[\mathrm{sign}\left(\stackrel{\&OverBar;}{{\mathrm{\&Delta;f}}_j}\right)\&times;L_{\mathrm{di}}-{\mathrm{ACE}}_{\mathrm{ij}}]\left\}\right\}{|}_{\left|\stackrel{\&OverBar;}{{\mathrm{\&Delta;f}}_j}\right|>{\mathrm{\&Delta;f}}_d}---\left(2\right)$

Zoning frequency security index, if I _fv>=0, then examine the frequency security qualified in region, wherein, described i is control area; Described T, for evaluating the period, can be 1 year, month or week etc.; Described j ∈ T evaluates the time point in period T, is spaced apart every 5 seconds one; Described L _difor the district control deviation limit value of control area i, unit MW; Described B _ifor the frequency bias coefficient that control area i is assigned with, be negative, unit MW/0.1Hz; Described for the average in 5 seconds before the system frequency difference of j time point, unit Hz, frequency difference is 1 sampled value per second; Described Δ f _dfor system frequency difference limit value, unit Hz; Described ACE _ijfor control area i is at the district control deviation of j time point, every 5 seconds 1 sampled values; Described sign is sign function, and its numerical value is

$\mathrm{sign}\left(x\right)=\left\{\begin{array}{c}1,x>0\\ 0,x=0\\ -1,x<0\end{array}\right..$

Specifically, the balance of active power in frequency departure reflection system cloud gray model, the time series that frequency deviation data is formed then embodies power balancing procedure during system cloud gray model, the frequency control performance of this process reflection system.Frequency difference time series is made up of the component of some different cycle of fluctuation.In frequency control, different regulating measures adjusts for the load fluctuation of different cycle of fluctuation.Wherein: Primary regulation is used for less, change load fluctuation comparatively frequently for level second; Secondary Control: manual adjustments and Automatic Generation Control be, load variations that change comparatively mild comparatively large for minute level then.One time frequency adjustment is carried out for load fluctuation more in small, broken bits, and Secondary Control mainly regulates comparatively mild load fluctuation.This means: on the one hand, based on the Secondary Control do not had, Primary regulation is good again, and its effect is also very limited, may can not meet the power demand of frequency adjustment; And the Primary regulation do not had, Secondary Control fully can not reach the quality requirements of frequency adjustment again.

Theory of probability theory shows, if frequency difference time series does not exist auto-correlation, only needs the quality level that frequency control can specified by a standard, such as: the root mean square of ACE average in 1 year limiting 10 minutes is less than a certain designated value.If there is not auto-correlation in frequency difference time series, then CPS2 standard redundancy (CPS1 designs for ACE1 minute average, and CPS2 was for 15 minutes).The development person of CPS standard points out, the engineering practice of control area and the AGC steering logic of employing cause frequency difference sequence to there is stronger autocorrelation.

System frequency is the primary goal that interconnected network is paid close attention to, because system frequency contains the information of two aspects: if system frequency difference at the appointed time in section (as: 1 year) meet the demands, show that system frequency is up-to-standard; And instantaneous frequency difference controls within the specific limits, mean that system active power comparatively balances, show system cloud gray model safety.Therefore, one of object that control performance assessment criteria is formulated ensures system frequency quality, this comprises two aspects: one is quality, namely control system frequency quality makes it to meet company standard and (as: requires under AGC puts into operation situation, interconnected network frequency controls by 50 ± 0.1Hz, qualification rate is not less than 99.99%), this needs to utilize the statistical indicator of frequency difference to evaluate; Two is safety, i.e. the safety requirements of demand fulfillment system all the time, and this should be weighed by the real-time indicator of frequency difference.

The focus that short time interval is paid close attention to is security of system.Therefore, what this time scale was paid close attention to is to exceed or each is evaluated the performance of main body close to during a certain specific frequency difference limit when frequency.The frequency control target paid close attention to due to this yardstick is a certain numerical intervals but not a certain fixed numbers; And when normally running, frequency reaches this interval bound by planned value needs certain hour, therefore utilize Secondary Control can realize in the ordinary course of things.

The evaluation method of this time scale can utilize when system frequency exceeds prescribed limit, according to the deviate be evaluated between the numerical value of main body A CE and its ACE limit value to evaluate its performance, the integrated value of this ACE deviate during frequency exceedes prescribed limits or average specifically can be adopted to describe.

Control area being caused to pursue ACE and frequency difference opposite sign for obtaining high target to the constraint of short time period in the existing CPS standard of China, if system cloud gray model frequency variation is frequent, then the number of times of ACE zero passage can be made than also many during employing A standard.This not only can increase the wearing and tearing of unit, also can cause the meaningless anxiety of dispatcher.And the standard adopting the present invention to retrain short time interval there will not be this situation.

Further, described setting module, specifically for:

Initialization system inadvertent exchange electric quantity limit value L _ti, evaluate period T;

Described evaluation module, specifically for:

Adopt formula (3)

Zoning frequency security index, if I _electricitywhen≤1, the control in region meets frequency security requirement, wherein, and described L _tifor inadvertent exchange electric quantity limit in the evaluation period t that control area i is prescribed, unit is MW, can make adjustment with running status or for customization, described in for control area i is in the average evaluating period t inner region control deviation, unit is MW.

Specifically, the inadvertent exchange electric quantity that main Focus Control of middle period is interregional, therefore, its realization is comparatively simple, the interconnection that only reality need be occurred exchanges electricity and compare with plan electricity, namely utilizes the average that is evaluated the ACE of main body in yardstick sometime or other indexs to compare with corresponding index limits.

Further, described setting module, specifically for:

Initialization system frequency quality criteria frequency difference limit value ε ₁, evaluate period T, region difference coefficient B;

Described evaluation module, specifically for:

Adopt formula (4) and (5)

${\mathrm{CF}}_1=\frac{1}{{\mathrm{\&epsiv;}}_1^2}\stackrel{\&OverBar;}{{\left\{\frac{\mathrm{ACE}}{-10B}\right\}}_1}\&times;{\stackrel{\&OverBar;}{\mathrm{\&Delta;f}}}_1---\left(4\right)$

I _quality=(2-AVG _t{ CF ₁) × 100% (5)

Zoning frequency quality index, if I _quality>=100%, then qualified by examination field frequency quality index, wherein, described AVG _tfor the mean value in the T period, described Δ f ₁for the system frequency difference mean value of 1 minute, unit is Hz, described B is examined the frequency bias coefficient in region, for negative, unit is MW/0.1Hz, and described control deviation is examined the district control deviation in region, unit is MW, described T is for evaluating the period, and unit is the moon, i.e. the historical data of the previous moon of the calculating use of each examination value.

Specifically, long duration pays close attention to frequency quality.What relate to due to it is frequency quality in comparatively long-term time period, therefore should utilize theory of probability statistical study means, is weighed by probability statistics index.North America CPS1 standard utilizes probability level to construct, and to be the frequency difference average of 1 minute be on average less than a certain designated value the rolling of a year to its control objectives.The frequency quality of China requires different from North America, is frequency qualification rate index, as: require that frequency controls by 50 ± 0.1Hz, qualification rate is not less than 99.99%.

By finding the analysis of frequency difference historical data, frequency substantially meets normal distribution and its average can be similar to and sees zero as.From above-mentioned conclusion, the probability meeting-4RMS{ Δ F}≤Δ f≤4RMS{ Δ F} is greater than 99.99%.

Due to enterprise frequency criterion of acceptability requirement-Δ f _d≤ Δ f≤+ Δ f _dprobability be greater than 99.99%, so, if RMS{ Δ F}≤Δ f _d/ 4, then-Δ f _d≤ Δ f≤+ Δ f _dprobability be greater than 99.99% naturally meet.If that is meet the company standard of frequency departure, frequency difference only need be made at the appointed time to meet following formula in section T.

RMS _T{ΔF}≤ε ₁(6)

${\mathrm{\&epsiv;}}_1=\frac{{\mathrm{\&Delta;f}}_d}{4}---\left(7\right)$

To consider in company standard generally with 1 year for time section investigates frequency qualification rate, therefore in the present embodiment, T is set as 1 year.

The embodiment of the present invention, the system parameter that evaluation module sets according to setting module, mains frequency, interconnecting ties power deviation that acquisition module gathers, mains frequency deviation, district control deviation that computing module calculates, evaluate operation of power networks control performance for different time scales.Thus control area both can have been guided to make adjustment fast, for system ensures that the frequency quality of mains frequency level second time scale lays the foundation, can tolerate again to make amends for one's faults by good deeds at certain yardstick in control area, thus reach the effect of energy-saving and emission-reduction.Achieve corresponding time scale and evaluate operation of power networks control performance, solve each regional power grid in prior art and run the frequent adjustment controlling to occur in enforcement and the problem excessively regulated, improve operation of power networks control efficiency.

Fig. 2 is that interconnected network of the present invention runs another structural representation of control performance evaluation system, and as shown in Figure 2, the system of the present embodiment, on the basis shown in Fig. 1, also comprises:

Memory module 105, for preserve described acquisition module gather mains frequency, interconnecting ties power deviation.

The present embodiment, the mains frequency of acquisition module collection, interconnecting ties power deviation store by memory module.Thus historical data values can be provided for system, be convenient to calculating and the system cloud gray model control performance corresponding to the statistical history time.

Last it is noted that above each embodiment is only in order to illustrate technical scheme of the present invention, be not intended to limit; Although with reference to foregoing embodiments to invention has been detailed description, those of ordinary skill in the art is to be understood that: it still can be modified to the technical scheme described in foregoing embodiments, or carries out equivalent replacement to wherein some or all of technical characteristic; And these amendments or replacement, do not make the essence of appropriate technical solution depart from the scope of various embodiments of the present invention technical scheme.

Claims (5)

1. interconnected network runs a control performance evaluation system, it is characterized in that, comprising:

Setting module, for the parameter of initialization system;

Acquisition module, for gathering mains frequency, interconnecting ties power deviation;

Computing module, for calculating mains frequency deviation, district control deviation;

Evaluation module, for according to described system parameter, described mains frequency, described mains frequency deviation, described interconnecting ties power deviation and described district control deviation, for different time scale evaluation region operation of power networks control performances.

2. system according to claim 1, is characterized in that, described setting module, specifically for:

Initialization system frequency security frequency difference limit value Δ f _d, field frequency Z-factor B _i, evaluate period T;

Described computing module, specifically for:

Adopt formula (1)

L _di＝-10B _iΔf _d(1)

The control deviation limit value of zoning;

Described evaluation module, specifically for:

Adopt formula (2)

$I_{\mathrm{fv}}={\left\{\underset{j\&Element;T}{\mathrm{\&Sigma;}}\right\{\mathrm{sign}\left(\stackrel{\&OverBar;}{{\mathrm{\&Delta;f}}_j}\right)\&times;[\mathrm{sign}\left(\stackrel{\&OverBar;}{{\mathrm{\&Delta;f}}_j}\right)\&times;L_{\mathrm{di}}-{\mathrm{ACE}}_{\mathrm{ij}}]\left\}\right\}|}_{\left|\stackrel{\&OverBar;}{{\mathrm{\&Delta;f}}_j}\right|>\mathrm{\&Delta;}{f}_d}---\left(2\right)$

Zoning frequency security index, if I _fv>=0, then examine the frequency security qualified in region, wherein, described i is control area; Described T, for evaluating the period, can be 1 year, month or week etc.; Described j ∈ T evaluates the time point in period T, is spaced apart every 5 seconds one; Described L _difor the district control deviation limit value of control area i, unit MW; Described B _ifor the frequency bias coefficient that control area i is assigned with, be negative, unit MW/0.1Hz; Described for the average in 5 seconds before the system frequency difference of j time point, unit Hz, frequency difference is 1 sampled value per second; Described Δ f _dfor system frequency difference limit value, unit Hz; Described ACE _ijfor control area i is at the district control deviation of j time point, every 5 seconds 1 sampled values; Described sign is sign function, and its numerical value is

$\mathrm{sign}\left(x\right)\left\{\begin{array}{c}1,x>0\\ 0,x=0\\ -1,x<0\end{array}\right..$

3. system according to claim 1, is characterized in that, described setting module, specifically for:

Initialization system inadvertent exchange electric quantity limit value L _ti, evaluate period T;

Described evaluation module, specifically for:

Adopt formula (3)

Zoning frequency security index, if I _electricitywhen≤1, the control in region meets frequency security requirement, wherein, and described L _tifor inadvertent exchange electric quantity limit in the evaluation period t that control area i is prescribed, unit is MW, can make adjustment with running status or for customization, described in for control area i is in the average evaluating period t inner region control deviation, unit is MW.

4. system according to claim 1, is characterized in that, described setting module, specifically for:

Initialization system frequency quality criteria frequency difference limit value ε ₁, evaluate period T, region difference coefficient B;

Described evaluation module, specifically for:

Adopt formula (4) and (5)

${\mathrm{CF}}_1=\frac{1}{{\mathrm{\&epsiv;}}_1^2}{\stackrel{\&OverBar;}{\left\{\frac{\mathrm{ACE}}{-10B}\right\}}}_1\&times;{\stackrel{\&OverBar;}{\mathrm{\&Delta;f}}}_1---\left(4\right)$

I _quality=(2-AVG _t{ CF ₁) × 100% (5)

Zoning frequency quality index, if I _quality>=100%, then qualified by examination field frequency quality index, wherein, described AVG _tfor the mean value in the T period, described Δ f ₁for the system frequency difference mean value of 1 minute, unit is Hz, described B is examined the frequency bias coefficient in region, for negative, unit is MW/0.1Hz, and described control deviation is examined the district control deviation in region, unit is MW, described T is for evaluating the period, and unit is the moon, i.e. the historical data of the previous moon of the calculating use of each examination value.

5. the system according to any one of claim 1-4, is characterized in that, also comprises:

Memory module, for preserving mains frequency, interconnecting ties power deviation that described acquisition module gathers.