CN103093319A - Power system communication emergency capacity assessment method - Google Patents

Abstract

A power system communication emergency capacity assessment method comprises that a relative-importance matrix of each branch node of a tree-form assessment graph of power system communication emergency capacity is established; the importance weight value of each node layer of the tree-form assessment graph is computed according to the importance matrix; the importance weight value is subjected to data consistency check to acquire screening importance weight value; and the power system communication emergency capacity is assessed according to the screening importance weight value and assessment score. According to the power system communication emergency capacity assessment method, a scientific and objective assessment means is used, affect on an assessment process because of unreasonable factors is removed to the maximum extent, and assessment results are high in accuracy.

Description

Power system communication emergency capacity evaluation method

Technical Field

The invention relates to the technical field of power engineering, in particular to a method for evaluating communication emergency capacity of a power system.

Background

In the power communication industry, the communication emergency capacity construction is increasingly regarded by the power industry as the communication emergency capacity for guaranteeing the emergency condition. At present, in emergency communication emergency capacity evaluation and emergency communication drilling evaluation in the power industry, an expert evaluation method is generally used, the method has more subjective factors and lacks of unified and scientific analysis technical means, so that the accuracy of the communication emergency capacity evaluation of a power system is low, and the obtained evaluation result often cannot truly reflect the objective communication emergency capacity condition.

Disclosure of Invention

Therefore, it is necessary to provide an evaluation method for communication emergency capability of a power system, aiming at the problem that the existing evaluation method is low in accuracy.

A power system communication emergency capacity evaluation method comprises the following steps:

constructing a relative importance matrix of each branch node of a tree-shaped evaluation graph of the communication emergency capacity of the power system;

respectively calculating the importance weight of each layer of node of the tree evaluation graph according to the importance matrix;

carrying out data consistency check on the importance weight to obtain a screening importance weight;

and evaluating the communication emergency capacity of the power system according to the screening importance weight and the evaluation score.

According to the method for evaluating the communication emergency capacity of the power system, the tree-shaped evaluation graph of the communication emergency capacity of the power system is constructed, the importance weight of each node of the tree-shaped evaluation graph is calculated, then data consistency inspection and screening are carried out on the importance weight, then the communication emergency capacity of the power system is evaluated according to the screened importance weight and the evaluation score, a scientific and objective evaluation means is adopted, the influence of unreasonable factors on the evaluation process is eliminated to the greatest extent, and the accuracy of an evaluation result is high.

Drawings

FIG. 1 is a flow diagram of a power system communication emergency capability assessment method according to an embodiment;

fig. 2 is a schematic diagram of a t-test coefficient table.

Detailed Description

The following describes in detail a specific embodiment of the method for evaluating communication emergency capability of an electric power system according to the present invention with reference to the accompanying drawings

Fig. 1 shows a flowchart of a power system communication emergency capability evaluation method according to an embodiment, which includes the following steps:

step S10: and constructing a relative importance matrix of each branch node of the tree-shaped evaluation graph of the communication emergency capacity of the power system.

In one embodiment, the process of step S10 specifically includes the following steps:

step S101, reading nodes of each layer of each branch of a tree-shaped evaluation graph of the communication emergency capacity of the power system; specifically, the tree-shaped evaluation graph is a topological graph constructed according to a tree-shaped evaluation system of the communication emergency capacity of the power system, and each node in the tree-shaped evaluation graph corresponds to each evaluation item of the tree-shaped evaluation system of the communication emergency capacity of the power system.

Step S102, two nodes x are respectively taken_i、x_jFinding x_i、x_jRatio of influence on upper node a_ijObtaining a relative importance matrix A for pairwise comparison, wherein A = (a)_ij)n×n，a_ij＞0，

(i≠j)，α_ij=1，(i＝j=1,2，…，n)。

Step S20: and respectively calculating the importance weight of each layer of node of the tree evaluation graph according to the importance matrix.

In one embodiment, the process of step S20 specifically includes the following steps:

step S201, calculating each row element a of the importance matrix A_ijProduct of (D) M_iWherein(i, j =1,2, …, n), n being the order of the matrix a, which corresponds to the number of evaluation items in the hierarchy.

Step S202, calculating M_iThe n-th square root of (A) to obtain a vector

Wherein,

corresponding to the solutions of the n-th root, respectively.

Step S203, vector quantity

Normalization processing is carried out to obtain the characteristic vector W of each node_iWherein

specifically, a unified evaluation standard is established after normalization processing.

Step S204, according to the characteristic vector W_iObtaining the importance weight of each node; in particular, the feature vector W_iA weight vector corresponding to each evaluation item.

In this embodiment, the obtained importance weight corresponding to each layer of node of each branch is calculated, the importance weight of each node is calculated for each level of the tree-shaped evaluation graph, and the weight value of each layer of evaluation item is constructed.

Step S30: and carrying out data consistency check on the importance weight to obtain a screening importance weight.

In one embodiment, the process of step S30 specifically includes the following steps:

step S301, judging the number of the importance weights according to a set threshold value, if the number is larger than or equal to the threshold value, executing step S301, and if the number is smaller than the threshold value, executing step S302; wherein, the threshold value is generally 10, and the importance weight can be given by an expert.

And step S302, carrying out data consistency check on the importance weight based on a 3 sigma criterion to obtain a screening importance weight.

In this embodiment, it is assumed that the importance weight only includes a random error, a standard deviation is calculated, an interval is determined according to a certain probability, if the error exceeds the interval, the error is not a random error but a coarse error, and then the importance weight including the error is removed.

Specifically, each importance weight Z obtained now_iAverage value of (2)

Substitute its reasonable value to obtain residual error

Then calculating by a Bessel (Bessel) formula to obtain a standard deviation S replacing the mean square error sigma;

$S=\sqrt{\frac{1}{N-1}\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{(Z_i-\stackrel{\‾}{Z})}^2}$

comparing the 3S value with each residual delta to obtain a certain importance weight Z_dIf its residual error is delta_dSatisfy | δ_d|>3S, judging the error as a gross error, and eliminating the importance weight Z_d。

And after each coarse error is eliminated, recalculating the S value of the rest importance weight, further judging whether the coarse errors exist based on the new S value with the reduced numerical value, if so, eliminating, repeating the operation until no coarse errors exist, and taking the rest importance weight as the screening importance weight.

Step S303, carrying out data consistency check on the importance weight based on the Romanofsky criterion to obtain a screening importance weight.

In this embodiment, the importance weight is [ Z ]₁,Z₂,…,Z_N]Suppose importance weight Z_dIf the data is suspicious, the data is pre-eliminated and then the average value is calculated

(excluding Z in the calculation)_d)；

$\stackrel{\‾}{Z}=\frac{1}{N-1}\underset{i=1,i\≠d}{\overset{N}{\mathrm{\Σ}}}{Z}_i$

And calculating its standard deviation S (excluding Z in calculation)_d)；

$S=\sqrt{\frac{1}{N-2}\underset{i=1,i\≠d}{\overset{N}{\mathrm{\Σ}}}{(Z_i-\stackrel{\‾}{Z})}^2}$

According to the measurement times N and the selected significance degree alpha, the t test coefficient K (N, alpha) is obtained by looking up the t test coefficient table shown in figure 2, if delta_dIf | ≧ K (n, α) S, the data Z_dIf the filtering importance weight contains the gross errors, the filtering importance weight is removed, otherwise, the filtering importance weight is retained, and the operations are repeated until all the importance weight containing the gross errors are removed, and the remaining importance weight is the filtering importance weight.

Step S40: and evaluating the communication emergency capacity of the power system according to the screening importance weight and the evaluation score.

In one embodiment, the process of step S40 specifically includes the following steps:

step S401, the evaluation scores corresponding to the bottom nodes are multiplied by the screening importance weights to obtain sub-item values of all branches; specifically, the items corresponding to the bottom nodes are evaluated to obtain evaluation scores, and the evaluation scores of the bottom nodes are multiplied by the screening importance weights to obtain quantitative data of the evaluation items corresponding to the bottom nodes.

Step S402, adding the subentry values to obtain a subentry evaluation value of each branch; specifically, the subentry value under each branch is added to obtain the subentry evaluation value of the branch.

Step S403, calculating the evaluation value of the root node at the uppermost layer of the tree evaluation graph by layer; specifically, the evaluation values of the branches are calculated from the bottom layer to the top layer, and finally, the evaluation value of the root node is obtained through calculation.

S404, evaluating the communication emergency capacity of the power system according to the root node evaluation value; specifically, the root node evaluation value calculated through the steps is used as an evaluation reference, and the communication emergency capacity of the power system is finally evaluated, so that the influence of unreasonable factors is avoided, and the probability of error evaluation is reduced.

The method for evaluating the communication emergency capacity of the power system starts from a large layer, decomposes evaluation contents layer by layer, constructs a tree-shaped evaluation topological graph, normalizes indexes of each layer by layer through hierarchical analysis, and can calculate a final result by layer by up-stepping only by judging each bottom index which can be judged during evaluation.

Furthermore, the data consistency check selection method based on the 3 sigma criterion or the Romannofski criterion analyzes and screens the importance weight, eliminates unreasonable weight, ensures the consistency of data and avoids influence of unreasonable factors on the evaluation result.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (5)

1. A power system communication emergency capacity evaluation method is characterized by comprising the following steps:

constructing a relative importance matrix of each branch node of a tree-shaped evaluation graph of the communication emergency capacity of the power system;

respectively calculating the importance weight of each layer of node of the tree evaluation graph according to the importance matrix;

carrying out data consistency check on the importance weight to obtain a screening importance weight;

and evaluating the communication emergency capacity of the power system according to the screening importance weight and the evaluation score.

2. The method for evaluating the communication emergency capacity of the power system according to claim 1, wherein the step of constructing the relative importance matrix of each branch node of the tree-shaped evaluation graph of the communication emergency capacity of the power system comprises the following steps:

reading nodes of each branch of the tree-shaped evaluation graph of the communication emergency capacity of the power system;

respectively taking two nodes x_i、x_jFinding x_i、x_jRatio of influence on upper node a_ijObtaining a relative importance matrix A for pairwise comparison, wherein A = (a)_ij)_n×n，a_ij＞0，

(i≠j)，a_ij=1，(i＝j=1,2，…，n)。

3. The method according to claim 1, wherein the step of calculating the importance weights of the nodes at each layer of the tree-shaped evaluation graph according to the importance matrix comprises:

calculating each row node a of the importance matrix A_ijProduct of (D) M_iWherein

(i, j =1,2, …, n), n being the order of the matrix a;

calculating M_iThe n-th square root of (A) to obtain a vector

Wherein,

for vector

Normalization processing is carried out to obtain the characteristic vector W of each node_iWherein

according to the feature vector W_iAnd obtaining the importance weight of each node.

4. The method according to claim 1, wherein the step of performing data consistency check on the importance weights to obtain screening importance weights comprises:

judging the number of the importance weights according to a set threshold value;

if the number is larger than or equal to the threshold value, carrying out data consistency check on the importance weight based on a 3 sigma criterion to obtain a screening importance weight;

and if the number is smaller than the threshold value, carrying out data consistency check on the importance weight based on the Romanofsky criterion to obtain a screening importance weight.

5. The method according to claim 1, wherein the step of evaluating the communication emergency capability of the power system according to the screening importance weight and the evaluation score comprises:

multiplying the evaluation value corresponding to the bottom node by the screening importance weight to obtain the sub-item value of each branch;

adding the sub-item values to obtain a sub-item evaluation value of each branch;

calculating the evaluation value of the root node at the uppermost layer of the tree evaluation graph by layer upward pushing;

and evaluating the communication emergency capacity of the power system according to the root node evaluation value.

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