CN105139286A - Method for evaluating validity of SCADA data on the basis of amount of reactive unbalance - Google Patents

Abstract

The invention discloses a method for evaluating the validity of SCADA data on the basis of amount of reactive unbalance. The method is characterized by acquiring the amount of reactive unbalance of both ends of a line by computing according to a voltage amplitude on both ends of the line, a current amplitude of the line, the impedance of the line, and a susceptance-to-ground parameter of the line; and acquiring the amount of reactive unbalance according to the reactive power of SCADA measurement data at both ends. In an ideal case, the computed amount of reactive unbalance is approximately equal to the measured amount of reactive unbalance. If a difference value between the computed amount of reactive unbalance and the measured amount of reactive unbalance is very large, the validity of the SCADA data at that time segment is very low. The method has beneficial effects of using the reactive power of measurement data as an evaluation index to accurately evaluate the validity of the measurement data, thereby accurately finding out data with poor validity in the measurement data and fast removing the data with poor validity.

Description

Based on the SCADA data validity appraisal procedure of idle amount of unbalance

Technical field

The present invention relates to bad data recognition and detection technique field, be specifically related to the efficiency assessment method of a kind of SCADA based on idle amount of unbalance (Monitoring and Controlling and data acquisition, SupervisoryControlandDataAcquisition) metric data.

Background technology

Along with the raising of Automation of Electric Systems level, Monitor and Control and data acquisition system (DAS) (SupervisoryControlAndDataAcquisition, SCADA) play more and more important effect in electrical network.The accuracy of SCADA metric data directly has influence on the accuracy of the state estimation, parameter identification, on-line load forcasting etc. of electrical network.Therefore, SCADA data play more and more important effect in electrical network.Along with the raising to power grid measurement precision, the WAMS system measurements device fast development with phase angle measurements amount is got up.Because PMU measuring equipment is expensive, be only arranged on more than 500kV and important outlet, therefore SCADA metric data still plays an important role in the scheduling of electrical network, and the validity assessing its metric data has very large practical value.

But, in SCADA data acquisition, be subject to larger random disturbance owing to measuring with transfer system; Measure the random failure occurred with transfer system; Systems in operation or disturb greatly the transient process etc. caused to have impact on the accuracy of metric data.The error of metric data, the situation such as can cause that tidal current analysis is not restrained.Therefore, the validity of our Water demand metric data, rejects the data that validity is poor.

For passing judgment on the validity of metric data, existing had a large amount of analysis and research both at home and abroad.Propose in prior art to use innovation graph approach to carry out the method for data validity assessment, the method based on the metric data with physical significance, and utilizes basic Circuit theory, reaches the object that assessment measures data validity.But the method more complicated, can only apply in emulated data, not there is practical engineering application and be worth.

Also proposed in prior art and use the validity of PMU and SCADA metric data to metric data to assess, but the method is for the outlet of not installing PMU measuring equipment, and inapplicable.Therefore, the method does not have the ubiquity of engineer applied.

Summary of the invention

Object of the present invention is exactly to solve the problem, propose a kind of SCADA data validity appraisal procedure based on idle amount of unbalance, the method with the reactive power of metric data for judging quota, accurate to the efficiency assessment of metric data, accurately can find out the data of validity difference in metric data, and data poor for validity are rejected fast.

To achieve these goals, the present invention adopts following technical scheme:

Based on a SCADA data validity appraisal procedure for idle amount of unbalance, comprising:

(1) collection needs the reactance X of the transmission line of electricity carrying out data validity assessment, the B of susceptance over the ground of transmission line of electricity I side ₁, transmission line of electricity II side the B of susceptance over the ground ₂;

(2) collection needs the transmission line of electricity two ends SCADA metric data carrying out data validity assessment; Described metric data comprises: the active power of transmission line of electricity, reactive power, voltage magnitude and current amplitude; The reference direction of electric current and power is all to flow into the direction of circuit for positive dirction;

(3) pre-service is carried out to the metric data at circuit two ends: the single-phase data each measurement amount in the metric data at circuit two ends being converted to uniform units;

(4) according to the transmission line of electricity related data collected in step (1) and step (2), the calculating of the idle amount of unbalance in circuit two ends is carried out respectively;

(5) the absolute length chang relative difference of the idle amount of unbalance in circuit two ends obtained respectively in calculation procedure (4);

(6) the threshold value λ of transmission line of electricity valid data is set _t, according to the relative difference of the idle amount of unbalance in circuit two ends calculated, judge the validity of described transmission line of electricity each period SCADA data;

(7) add up the ratio of valid data in the transmission line of electricity SCADA metric data in setting-up time section, judge by gained ratio the levels of precision that transmission line of electricity two ends measurement equipment measures.

In described step (4), the method according to the idle amount of unbalance in circuit SCADA metric data computational scheme two ends collected in step (2) is specially:

Q _lm＝Q ₁+Q ₂；

Wherein, Q _lmfor the measurement amount of the idle imbalance power at k period circuit two ends, Q ₁for the reactive power measurement amount of k period circuit I side, Q ₂for the measurement amount of k period circuit II side reactive power.

In described step (4), the method according to the idle amount of unbalance in circuit real data computational scheme two ends collected in step (1) is specially:

$Q_{lc}={I_{12}}^{2}X-U_1^2{B}_1-{U_2}^2{B}_2\≈{\left(\frac{I_1+I_2}{2}\right)}^{2}X-U_1^2{B}_1-{U_2}^2{B}_2;$

Wherein, Q _lcfor the calculated amount of the idle imbalance power in k period circuit two ends; I ₁₂for flow through line impedance electric current, U ₁for the measurement voltage magnitude of k period circuit I side, U ₂for the measurement voltage magnitude of k period circuit II side, I ₁for the measured current amplitude of k period circuit I side, I ₂for the measured current amplitude of k period circuit II side, X is line reactance, B ₁for the susceptance over the ground of circuit I side, B ₂for the susceptance over the ground of circuit II side.

In described step (5), the method for the absolute difference of the idle amount of unbalance in circuit two ends obtained respectively in calculation procedure (4) is:

ΔQ _l＝|Q _lm-Q _lc|；

Wherein, Δ Q _lfor the absolute difference of the idle imbalance power in k period circuit two ends; Q _lmfor the measurement amount of the idle imbalance power at k period circuit two ends, Q _lcfor the calculated amount of the idle imbalance power in k period circuit two ends.

In described step (5), the method for the relative difference of the idle amount of unbalance in circuit two ends obtained respectively in calculation procedure (4) is:

$E_Q=\frac{\left|Q_{lm}-Q_{lc}\right|}{\left|Q_{lc}\right|};$

Wherein, E _qfor passing judgment on the reactive power index of metric data validity, Q _lmfor the measurement amount of the idle imbalance power at k period circuit two ends, Q _lcfor the calculated amount of the idle imbalance power in k period circuit two ends.

In described step (6),

If the relative difference of certain the idle amount of unbalance in period circuit two ends obtained is greater than the threshold value λ of setting _t, then judge that this period validity of transmission line of electricity SCADA metric data is poor, the metric data of this period rejected;

If the relative difference of the idle amount of unbalance in circuit two ends obtained is less than the threshold value of setting, λ _tthen judge that the validity of transmission line of electricity SCADA metric data is high;

In described step (7), in the transmission line of electricity SCADA metric data in statistics setting-up time section, the method for the ratio of valid data is:

$\mathrm{\η}=(1-\frac{n}{k})*100\%;$

Wherein, η is the valid data ratio of k period metric data; N is the poor metric data number of k lime period availability, and k is the time hop count of circuit two ends metric data.

If this ratio is lower than 50%, then illustrates that this circuit two ends measurement equipment measures precision lower, can study further, consider whether change.

The invention has the beneficial effects as follows:

The inventive method with the reactive power of metric data for judging quota, accurate to the efficiency assessment of metric data, accurately can find out the data of validity difference in metric data, and data poor for validity are rejected fast.The method is directed to SCADA metric data, has wide range of applications.In addition, the method is simply easy to operation, can be applicable in Practical Project, can be the appraisal procedure that dispatcher provides metric data quality, improve the accuracy of Load flow calculation, state estimation etc.

The point of penetration using idle amount of unbalance to assess as SCADA data validity, do not need to set up complicated node incidence matrix, method is simple, and execution speed is fast.Can carry out the differentiation of SCADA metric data validity, assessment accurately.

Compared with the existing error in measurement analytical approach based on PMU metric data, the method can be applicable to SCADA metric data, and range of application is wider, and engineering adaptability is strong.

By embodiment, this invention can be applicable to, in Practical Project, to have actual application value.In practice, for grasping electrical power system metric data quality, carry out Load flow calculation etc. reference be provided.

The present invention can be applicable to the metric data efficiency assessment that circuit two ends are equiped with measuring equipment.Be particularly useful for the metric data efficiency assessment that SCADA measuring equipment has been installed at two ends.

Accompanying drawing explanation

Fig. 1 is embodiment of the present invention transmission line of electricity Equivalent Model schematic diagram;

Fig. 2 is the inventive method process flow diagram;

Fig. 3 is measured data of the present invention section measurement loss sometime and computed losses comparison diagram;

Fig. 4 is emulated data of the present invention section measurement loss sometime and computed losses comparison diagram.

Embodiment:

Below in conjunction with accompanying drawing and embodiment, the present invention will be further described:

A kind of SCADA data validity appraisal procedure based on idle amount of unbalance.Utilize the correlation parameter of the voltage magnitude at circuit two ends, current amplitude, reactive power and circuit, to reach the validity problem passing judgment on circuit two ends SCADA data.This method by coding, according to the impedance of the voltage magnitude at circuit two ends, current amplitude, circuit and susceptance parameter (supposing that this electric parameters is accurate) over the ground, calculates the idle amount of unbalance at circuit two ends.Reactive power according to the SCADA metric data at two ends also can obtain idle amount of unbalance.In the ideal case, the idle amount of unbalance approximately equal that the idle amount of unbalance calculated obtains with measurement, when difference is larger, then illustrates that the SCADA data validity of this period is on the low side between the two.

Specifically comprise the following steps:

(1) transmission line of electricity Equivalent Model as shown in Figure 1, gathered the correlation parameter of transmission line of electricity by concrete voltage and current measurement equipment.The correlation parameter of incoming line comprises: the reactance X of circuit and the B of susceptance over the ground of circuit I side ₁, the B of susceptance over the ground of circuit II side ₂.

(2) need by data-interface collection the circuit two ends SCADA metric data carrying out data validity assessment.Metric data comprises: active power, reactive power, voltage magnitude, current amplitude.The reference direction of electric current and power is all to flow into the direction of circuit for positive dirction.

(3) pre-service is carried out to the metric data at circuit two ends.Each measurement amount in the metric data at circuit two ends is converted to phase data or the line data of uniform units.

(4) calculating of the idle amount of unbalance difference in circuit two ends is carried out.Concrete steps are:

1) according to the measurement amount of the reactive power of the SCADA metric data at circuit two ends, the idle imbalance power in circuit two ends is asked for.Asking for equation is

Q _lm＝Q ₁+Q ₂(1)

Wherein Qlm is the measurement amount of the idle imbalance power at k period circuit two ends, and Q1 is the reactive power measurement amount of k period circuit I side, and Q2 is the measurement amount of k period circuit II side reactive power.

2) 1) complete after, the calculated amount of computational scheme two ends are idle amount of unbalance.Computing formula is:

$Q_{lc}={I_{12}}^{2}X-U_1^2{B}_1-{U_2}^2{B}_2\≈{\left(\frac{I_1+I_2}{2}\right)}^{2}X-U_1^2{B}_1-{U_2}^2{B}_2---\left(2\right)$

With reference to the accompanying drawings 1, in formula, Q _lcfor the calculated amount of the idle imbalance power in k period circuit two ends.I ₁₂for flow through line impedance electric current, U ₁for the measurement voltage magnitude of k period circuit I side, U ₂for the measurement voltage magnitude of k period circuit II side, I ₁for the measured current amplitude of k period circuit I side, I ₂for the measured current amplitude of k period circuit II side, X is line reactance, B ₁for the susceptance over the ground of circuit I side, B ₂for the susceptance over the ground of circuit II side.

3) 2) complete after, ask for the absolute value of the idle imbalance power difference in circuit two ends, be absolute difference.Computing formula is:

ΔQ _l＝|Q _lm-Q _lc|(3)

In formula, Δ Q _lfor the absolute difference of the idle imbalance power in k period circuit two ends.Q _lmfor the measurement amount of the idle imbalance power at k period circuit two ends, Q _lcfor the calculated amount of the idle imbalance power in k period circuit two ends.When the metric data at circuit two ends is ideal value, Δ Q _lbe almost 0.In actual amount examining system, circuit two ends metric data validity is higher, Δ Q _lmore close to 0.

4) 3) terminate after, ask for the relative difference of the idle imbalance power in circuit two ends, be called the reactive power index passing judgment on metric data validity.Computing formula is:

$E_Q=\frac{\left|Q_{lm}-Q_{lc}\right|}{\left|Q_{lc}\right|}---\left(4\right)$

In formula, E _qfor passing judgment on the reactive power index of metric data validity, Q _lmfor the measurement amount of the idle imbalance power at k period circuit two ends, Q _lcfor the calculated amount of the idle imbalance power in k period circuit two ends.

(5) a threshold value λ is set _t, when the correlation parameter of circuit two ends metric data is not less than threshold value, thinks that this period metric data is effective, when the correlation parameter of circuit two ends metric data is greater than this threshold value, think that the metric data of this period is invalid.

(6) according to threshold value, the validity of circuit two ends metric data is determined.According to threshold value λ _tpick out the metric data that circuit two ends reactive power index is greater than threshold value, then this data validity is poor.Count the metric data number that validity is poor, count n.For not affecting the accuracy of Power Network Status Estimation, Load flow calculation etc., the metric data of period can reject this.

(7) add up the ratio of valid data in the metric data of a period of time, judge the accuracy of this circuit two ends measurement equipment.Asking for equation is:

$\mathrm{\η}=(1-\frac{n}{k})*100\%---\left(5\right)$

Wherein, η is the valid data ratio of this k period metric data.N is the poor metric data number of k lime period availability, and k is the time hop count of circuit two ends metric data.

If this ratio is lower than 50%, then illustrates that this circuit two ends measurement equipment measures precision lower, can study further, consider whether change.

Below by specific embodiment, the inventive method is described:

(1) as shown in Figure 1, the correlation parameter of transmission line of electricity is gathered by concrete voltage and current measurement equipment, the impedance of circuit and over the ground susceptance.In this example, the reactance parameter X=8.1956 of circuit, over the ground susceptance parameter B ₁=B ₂=1.6431*10^ (-5) Ω;

(2) need by data-interface collection the circuit two ends SCADA metric data carrying out data validity assessment.Comprise the active power of metric data, reactive power, voltage magnitude, current amplitude.This example comprises the metric data of 500 time periods altogether.Illustrate to the metric data of first period, in Fig. 1, the metric data at circuit two ends is as shown in the table:

Table 1

U 1(kV)	I 1(A)	P 1(MW)	Q 1(MVar)	U 2(kV)	I 2(A)	P 2(MW)	Q 2(MVar)
								228.8	325.5	-124.8	-22.30	230.1	323.9	125.8	19.25

In table 1, U ₁for I side voltage magnitude, I ₁for I side current amplitude; U ₂for II side voltage magnitude; I ₂for II side current amplitude; P ₁for I side electric current active power, P ₂for II side active power; Q ₁for I side electric current reactive power, Q ₂for II side reactive power.The unit of each measurement amount as shown in the tables.

(3) pre-service is carried out to the metric data at circuit two ends.Each measurement amount in the metric data at circuit two ends is converted to phase data or the line data of uniform units.

Table 2

U 1(kV)	I 1(kA)	U 2(kV)	I 2(kA)	P 1(MW)	Q 1(Mvar)	P 2(MW)	Q 2(Mvar)
								132.1	0.325	132.8	0.3239	-41.60	-7.434	41.94	6.417

In table 2, U ₁for I side voltage magnitude, I ₁for I side current amplitude; U ₂for II side voltage magnitude; I ₂for II side current amplitude; P ₁for I side electric current active power, P ₂for II side active power; Q ₁for I side electric current reactive power, Q ₂for II side reactive power.The unit of each measurement amount as shown in the tables.

(4) calculating of the idle amount of unbalance difference in circuit two ends is carried out.Concrete steps are:

1) according to the measurement amount of the reactive power of the SCADA metric data at circuit two ends, the idle imbalance power in circuit two ends is asked for.According to formula (1), to the citing of the first period, the measurement amount Q of circuit two ends are idle imbalance power _lm=-1.017MVar.

2) calculated amount of the idle amount of unbalance in computational scheme two ends.For the first period, use computing formula (2), obtain the difference Q of the idle imbalance power in circuit two ends _lc=-0.8360.The idle imbalance power measurement amount of 500 time periods and calculated amount be as shown in Figure 3:

3) ask for the absolute value of the idle imbalance power difference in circuit two ends, be absolute difference.Use computing formula (3), obtain the absolute value delta Q of the first period idle imbalance power difference _l=0.1812.

4) ask for the relative difference of the idle imbalance power in circuit two ends, be called the reactive power index passing judgment on metric data validity.Formula (4) is used to try to achieve the reactive power index E of the first period _q=0.217.

(5) a threshold value λ is set _t, threshold value λ is set in this example _t=0.5.

(6) according to threshold value, the validity of circuit two ends metric data is determined.According to threshold value λ _t, pick out the metric data that circuit two ends reactive power index is greater than threshold value, then this data validity is poor.Count the metric data number that validity is poor, count n.According to threshold value, in this example, the data validity having 36 periods is poor, n=36.Wherein with reactive power index E _qthe period of=1.422 is example, this period data considerably beyond threshold value, as used O to mark in accompanying drawing 3, now corresponding metric data is the data of 01-1001:48 period, illustrate that the data validity of this period is poor, can reject, improve market demand precision.

(7) ratio of valid data in the metric data of a period of time is added up.According to asking for equation (5), n=36, k=500, η=92.8% can be obtained.This ratio, considerably beyond 50%, illustrates that this circuit two ends measurement equipment error in measurement is little.

Experiment effect

With the circuit model shown in accompanying drawing 1 for object, with the method flow of accompanying drawing 2 for foundation, design the validity of following Example Verification the inventive method.Suppose circuit X=10.124 Ω in accompanying drawing 1, over the ground susceptance parameter B ₁=B ₂=7.377*10^ (-5) Ω.

A certain period circuit two ends SCADA metric data form is as shown in table 3.

Table 3

U 1(kV)	I 1(A)	U 2(kV)	I 2(A)	P 1(MW)	Q 1(Mvar)	P 2(MW)	Q 2(Mvar)
								304.414	436.4539	303.894	438.5211	132.9	0.2671	-132.7	-11.98

This metric data is desirable metric data.In form, U ₁for I side voltage magnitude, I ₁for I side current amplitude; U ₂for I side voltage magnitude; I ₂for II side current amplitude; P ₁for I side electric current active power, P ₂for II side active power; Q ₁for I side electric current reactive power, Q ₂for II side reactive power.The unit of each measurement amount as shown in the tables.

In above metric data, stochastic error signal is added to a certain period, form the SCADA emulated data of the multiple periods with error in measurement.Threshold value is set as 0.05.

Consider following four kinds of situations: 1. the voltage magnitude of circuit two ends a certain period has the reactive power amplitude of the current amplitude of the error circuit two ends a certain period of 5% have the error of 5% 2. circuit two ends a certain period to have the error of 5%

By the inventive method, effectively can determine the poor metric data of validity, and its position can be obtained, so that reject the metric data that validity is poor.

From above-mentioned result of calculation, the method can pick out the validity of multi-period SCADA metric data.The Data Position poor for validity also can accurately determine.For 1., it is idle amount of unbalance power scale and idle uneven rated output as shown in Figure 4, when without error in measurement, with reference to loss with measure loss and almost overlap.When measuring data validity and being poor, measurement loss and computed losses have obvious gap, and the data point O that wherein validity is poor marks.

By reference to the accompanying drawings the specific embodiment of the present invention is described although above-mentioned; but not limiting the scope of the invention; one of ordinary skill in the art should be understood that; on the basis of technical scheme of the present invention, those skilled in the art do not need to pay various amendment or distortion that creative work can make still within protection scope of the present invention.

Claims (7)

1., based on a SCADA data validity appraisal procedure for idle amount of unbalance, it is characterized in that, comprising:

(1) collection needs the reactance X of the transmission line of electricity carrying out data validity assessment, the B of susceptance over the ground of transmission line of electricity I side ₁, transmission line of electricity II side the B of susceptance over the ground ₂;

(2) collection needs the transmission line of electricity two ends SCADA metric data carrying out data validity assessment; Described metric data comprises: the active power of transmission line of electricity, reactive power, voltage magnitude and current amplitude; The reference direction of electric current and power is all to flow into the direction of circuit for positive dirction;

(3) pre-service is carried out to the metric data at circuit two ends: the single-phase data each measurement amount in the metric data at circuit two ends being converted to uniform units;

(4) according to the transmission line of electricity related data collected in step (1) and step (2), the calculating of the idle amount of unbalance in circuit two ends is carried out respectively;

(5) the absolute length chang relative difference of the idle amount of unbalance in circuit two ends obtained respectively in calculation procedure (4);

(6) the threshold value λ of transmission line of electricity valid data is set _t, according to the relative difference of the idle amount of unbalance in circuit two ends calculated, judge the validity of described transmission line of electricity each period SCADA data;

(7) add up the ratio of valid data in the transmission line of electricity SCADA metric data in setting-up time section, judge by gained ratio the levels of precision that transmission line of electricity two ends measurement equipment measures.

2. a kind of SCADA data validity appraisal procedure based on idle amount of unbalance as claimed in claim 1, it is characterized in that, in described step (4), the method according to the idle amount of unbalance in circuit SCADA metric data computational scheme two ends collected in step (2) is specially:

Q _lm＝Q ₁+Q ₂；

Wherein, Q _lmfor the measurement amount of the idle imbalance power at k period circuit two ends, Q ₁for the reactive power measurement amount of k period circuit I side, Q ₂for the measurement amount of k period circuit II side reactive power.

3. a kind of SCADA data validity appraisal procedure based on idle amount of unbalance as claimed in claim 1, it is characterized in that, in described step (4), the method according to the idle amount of unbalance in circuit real data computational scheme two ends collected in step (1) is specially:

$Q_{lc}={I_{12}}^{2}X-U_1^2{B}_1-{U_2}^2{B}_2\≈{\left(\frac{I_1+I_2}{2}\right)}^{2}X-U_1^2{B}_1-{U_2}^2{B}_2;$

Wherein, Q _lcfor the calculated amount of the idle imbalance power in k period circuit two ends; I ₁₂for flow through line impedance electric current, U ₁for the measurement voltage magnitude of k period circuit I side, U ₂for the measurement voltage magnitude of k period circuit II side, I ₁for the measured current amplitude of k period circuit I side, I ₂for the measured current amplitude of k period circuit II side, X is line reactance, B ₁for the susceptance over the ground of circuit I side, B ₂for the susceptance over the ground of circuit II side.

4. a kind of SCADA data validity appraisal procedure based on idle amount of unbalance as claimed in claim 1, it is characterized in that, in described step (5), the method for the absolute difference of the idle amount of unbalance in circuit two ends obtained respectively in calculation procedure (4) is:

ΔQ _l＝|Q _lm-Q _lc|；

Wherein, Δ Q _lfor the absolute difference of the idle imbalance power in k period circuit two ends; Q _lmfor the measurement amount of the idle imbalance power at k period circuit two ends, Q _lcfor the calculated amount of the idle imbalance power in k period circuit two ends.

5. a kind of SCADA data validity appraisal procedure based on idle amount of unbalance as claimed in claim 1, it is characterized in that, in described step (5), the method for the relative difference of the idle amount of unbalance in circuit two ends obtained respectively in calculation procedure (4) is:

$E_Q=\frac{\left|Q_{lm}-Q_{lc}\right|}{\left|Q_{lc}\right|};$

Wherein, E _qfor passing judgment on the reactive power index of metric data validity, Q _lmfor the measurement amount of the idle imbalance power at k period circuit two ends, Q _lcfor the calculated amount of the idle imbalance power in k period circuit two ends.

6. a kind of SCADA data validity appraisal procedure based on idle amount of unbalance as claimed in claim 1, is characterized in that, in described step (6),

If the relative difference of certain the idle amount of unbalance in period circuit two ends obtained is greater than the threshold value λ of setting _t, then judge that this period validity of transmission line of electricity SCADA metric data is poor, the metric data of this period rejected;

If the relative difference of the idle amount of unbalance in circuit two ends obtained is less than the threshold value of setting, λ _tthen judge that this period validity of transmission line of electricity SCADA metric data is high.

7. a kind of SCADA data validity appraisal procedure based on idle amount of unbalance as claimed in claim 1, it is characterized in that, in described step (7), in the transmission line of electricity SCADA metric data in statistics setting-up time section, the method for the ratio of valid data is:

$\mathrm{\η}=(1-\frac{n}{k})*100\%;$

Wherein, η is the valid data ratio of k period metric data; N is the poor metric data number of k lime period availability, and k is the time hop count of circuit two ends metric data.