Load loss fault severity quantification method and system for power system

Abstract

The invention discloses a power system load loss fault severity quantification method and system. The method comprises the following steps: constructing a load loss fault severity quantification system; counting the loss load electric quantity of the secondary index; calculating a second-level index load loss electric quantity risk weight; carrying out weighted summation on the loss-of-load electric quantity of the second-level index and the loss-of-load electric quantity risk weight of the second-level index to obtain the loss-of-load electric quantity of the first-level index; calculating a first-level index load loss electric quantity risk weight; carrying out weighted summation on the loss-of-load electric quantity of the first-level index and the loss-of-load electric quantity risk weight of the first-level index to obtain the loss-of-load electric quantity of a zero-level index; and evaluating the load loss risk according to the load loss electric quantity of the zero-level index. According to the scheme provided by the invention, when the risk of the superior power grid is evaluated and the superior power grid is evaluated, the lower power grid is taken as a basic unit to evaluate and calculate the consequence severity score by considering the difference factor of each region, so that the evaluation result more accurately reflects the load reduction severity degree.

Description

Technical Field

[0001] The present invention relates to the technical field of power system safety risks, and in particular to a method and system for quantifying the severity of a power system load loss fault. Background Art

[0002] The current method for quantifying the severity of power system load loss failures is to provide a score table for the severity of consequences at the provincial and municipal grid levels based on the object of grid security risk assessment and the possible scope of consequences of grid security risks; the severity of consequences is divided into five levels: extra-large losses, major losses, large losses, general A-level losses, and general B-level losses, based on the possible threats to grid security and the severity of load losses. When evaluating a certain level of grid, the severity of consequences is quantified based on the total amount of load reduction at that level of grid with reference to the score table.

[0003] The above method has the advantages of simple calculation method, strong intuitiveness and simplicity, and can accurately grasp the severity of the overall system load loss risk from a macro perspective by reducing the load of the provincial power grid. However, when evaluating the risk of the upper power grid, this method does not distinguish the importance of each city-level area in the provincial power grid and the importance and distribution of each regional load, which makes the method have a certain degree of concealment. Summary of the invention

[0004] In view of the problem pointed out in the background technology that the current method for quantifying the severity of load loss failure in a power system does not distinguish the importance of each city-level area in the provincial power grid and the importance and distribution of each regional load when evaluating the risk of the superior power grid, thereby causing a certain degree of masking in the method, the purpose of the present invention is to provide a method and system for quantifying the severity of load loss failure in a power system.

[0005] To achieve the purpose of the present invention, the technical solution provided by the present invention is specifically as follows:

[0006] First aspect

[0007] The present invention provides a method for quantifying the severity of a load loss fault in an electric power system, comprising the following steps:

[0008] Step S1: construct a load loss fault severity quantification system divided according to administrative regions and refined layer by layer, wherein the load loss fault severity quantification system uses the provincial load loss quantity as the zero-level indicator, and the zero-level indicator includes three first-level indicators: the load reduction of the prefecture-level city power grid, the load reduction of the county-level city power grid, and the load reduction of the county-level power grid. Each first-level indicator includes multiple second-level indicators formed by the load reduction of the power grid in a specific administrative region;

[0009] Step S2: Count the load loss power of the secondary indicator;

[0010] Step S3: Calculate the risk weight of the secondary indicator load loss electricity;

[0011] Step S4: weighted summing the load loss electricity of the secondary indicator and the risk weight of the load loss electricity of the secondary indicator to obtain the load loss electricity of the primary indicator;

[0012] Step S5: Calculate the risk weight of the first-level indicator load loss electricity;

[0013] Step S6: weighted sum of the load loss power of the first-level indicator and the risk weight of the load loss power of the first-level indicator to obtain the load loss power of the zero-level indicator;

[0014] Step S7: Evaluate the load loss risk according to the load loss power of the zero-level indicator.

[0015] Second aspect

[0016] Corresponding to the above method, the present invention also provides a power system load loss fault severity quantification system, including the following units: a quantification system construction unit, a load loss electricity statistical unit of a secondary indicator, a secondary indicator load loss electricity risk weight calculation unit, a primary indicator load loss electricity acquisition unit, a primary indicator load loss electricity risk weight calculation unit, a zero-level indicator load loss electricity calculation unit, and a load loss risk assessment unit;

[0017] The quantification system building unit is used to construct a load loss fault severity quantification system that is divided according to administrative regions and refined layer by layer. The load loss fault severity quantification system uses the provincial load loss quantity as the zero-level indicator. The zero-level indicator includes three first-level indicators: the load reduction of the prefecture-level city power grid, the load reduction of the county-level city power grid, and the load reduction of the county-level power grid. Each first-level indicator includes multiple second-level indicators formed by the load reduction of the power grid in a specific administrative region;

[0018] The load loss electricity statistical unit of the secondary indicator is used to count the load loss electricity of the secondary indicator;

[0019] The secondary indicator load loss electricity risk weight calculation unit is used to calculate the secondary indicator load loss electricity risk weight;

[0020] The first-level indicator load loss power acquisition unit is used to weighted sum the second-level indicator load loss power and the second-level indicator load loss power risk weight to obtain the first-level indicator load loss power;

[0021] The first-level indicator load loss electricity risk weight calculation unit is used to calculate the first-level indicator load loss electricity risk weight;

[0022] The zero-level index load loss power calculation unit is used to weighted sum the first-level index load loss power and the first-level index load loss power risk weight to obtain the zero-level index load loss power;

[0023] The load loss risk assessment unit is used to assess the load loss risk according to the load loss power of the zero-level indicator.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This application provides a solution that distinguishes the importance of each city-level region in the provincial power grid and the importance and distribution of each regional load when evaluating the risks of the upper-level power grid. When evaluating the upper-level power grid, the lower-level power grid is used as the basic unit for evaluation and the severity score of the consequences is calculated by considering the differences between regions, so that the evaluation results more accurately reflect the severity of the load reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the method flow provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] In order to eliminate the masking phenomenon of the current evaluation method, when evaluating the upper power grid, the lower power grid should be used as the basic unit for evaluation and the severity score of the consequences should be calculated by considering the differences in various regions, so that the evaluation results can more accurately reflect the severity of the load reduction. Therefore, this paper improves the existing evaluation method of Hainan power grid, and establishes a quantitative evaluation model for the load loss risk of Hainan power grid based on the hierarchical analysis method and the scoring method, thereby eliminating the masking phenomenon to a certain extent.

[0029] like Figure 1 As shown, this embodiment provides a method for quantifying the severity of a load loss fault in a power system, comprising the following steps:

[0030] Step S1: construct a load loss fault severity quantification system divided according to administrative regions and refined layer by layer, wherein the load loss fault severity quantification system uses the provincial load loss quantity as the zero-level indicator, and the zero-level indicator includes three first-level indicators: the load reduction of the prefecture-level city power grid, the load reduction of the county-level city power grid, and the load reduction of the county-level power grid. Each first-level indicator includes multiple second-level indicators formed by the load reduction of the power grid in a specific administrative region;

[0031] Step S2: Count the load loss power of the secondary indicator;

[0032] Step S3: Calculate the risk weight of the secondary indicator load loss electricity;

[0033] When using the above improved method to evaluate the load loss of provincial power grids, it is very important to properly determine the relative weights between power grids in various regions in order to better eliminate the shadowing phenomenon. The method of calculating the relative weights of each element in the hierarchical analysis method can use less quantitative information to mathematically and simplify relatively complex decision-making problems with multiple objectives and multiple criteria to a certain extent.

[0034] Using the hierarchical analysis method, it is necessary to first analyze the various factors contained in the complex system and group these factors in a logical order to form an orderly hierarchical structure. Then compare the relative importance of each factor in each layer to establish a judgment matrix. By calculating the maximum eigenvalue of the matrix and its corresponding eigenvector, the importance order of each element in the next layer to a certain element in the previous layer is obtained to establish the corresponding weight vector. The details are as follows:

[0035] First: Determine the judgment matrix

[0036] The elements in the judgment matrix are determined by comparing the factors at the same level in the risk assessment model, as shown below.

[0037]

[0038] In the matrix, B i Corresponding to B1 to Bn in the above matrix, it represents the i-th factor in a certain layer of the risk assessment model, a ij Corresponding to a11 to a1n in the above matrix, its values ​​and meanings are shown in Table 1. The judgment scale in the table refers to the scores given to different situations when comparing two factors using the scoring method.

[0039] Table 1

[0040]

[0041] In addition, when there are many factors to be compared, in order to avoid logical errors, the 0-2 three-scale method can be used to compare each factor pairwise, establish a comparison matrix and calculate the ranking index of each factor, and then transform the comparison matrix into a judgment matrix through transformation.

[0042] Table 2

[0043]

[0044] Second: Calculate the relative weight of each factor

[0045] The following describes the process of calculating relative weights using the 1-9 point scale method and the 0-2 point three-point scale method.

[0046] (1) Using a 1-9 scale

[0047] Assume that a certain layer in the quantitative system construction unit is composed of n common factors, and its judgment matrix is

[0048]

[0049] Among them, w i >0, w i Corresponding to w1 to wn in the above matrix, representing the weight of the i-th element, let

[0050] a ij =w i / w j

[0051] to a ij Taking the product of rows, we get

[0052]

[0053] Will Taking the nth power, we get

[0054]

[0055] Will Normalized, we get

[0056]

[0057] Then W=(w1,w2,…,w n ) T , which is the approximate characteristic root, that is, the weight vector; calculate This is the approximate value of the largest characteristic root.

[0058] In order to determine whether the same comparison standard is maintained for each risk factor when constructing the judgment matrix, it is also necessary to test the consistency of matrix A.

[0059]

[0060] It is called the consistency index; denoted by K RI is the average consistency index, see Table 5, K CR =K CI / K RI is the random consistency ratio. CR When <0.1, the judgment matrix is ​​considered to have satisfactory consistency, otherwise the judgment matrix should be reconstructed.

[0061] The average consistency index is shown in Table 3.

[0062] Table 3

[0063]

[0064] (2) Using a 0-2 point scale

[0065] A comparison matrix was established by comparing the factors in the same layer pairwise using the 0-2 scale method, and the ranking index of the importance of each factor was calculated. i ,Right now

[0066]

[0067] The comparison matrix is ​​transformed into a judgment matrix using the range method. The element values ​​in the judgment matrix are

[0068]

[0069] Among them, the range R is defined as

[0070] R=r max -r min

[0071] r max and r min The definition is as follows

[0072]

[0073] Among them, c b is a constant, which is the relative importance of the extreme element pair given by a certain standard cosine function (in practice, c b Generally, 9 is taken.

[0074] Step S4: weighted summing the load loss electricity of the secondary indicator and the risk weight of the load loss electricity of the secondary indicator to obtain the load loss electricity of the primary indicator;

[0075] Step S5: Calculate the risk weight of the first-level indicator load loss electricity;

[0076] It should be noted that the risk weight of the first-level indicator of lost load electricity refers to the method of calculating the risk weight of the second-level indicator of lost load electricity, which will not be repeated here;

[0077] Step S6: weighted sum of the load loss power of the first-level indicator and the risk weight of the load loss power of the first-level indicator to obtain the load loss power of the zero-level indicator;

[0078] Step S7: Evaluate the load loss risk according to the load loss power of the zero-level indicator.

[0079] Among them, in step S3, the risk weight of the secondary indicator load loss electricity is a relative weight.

[0080] Among them, the methods for calculating the risk weight of the secondary indicator load loss electricity include the 1-9 point scale method and the 0-2 point three-scale method.

[0081] Wherein, in step S7, the calculation formula of the magnitude of the load loss power of the zero-level indicator is as follows:

[0082]

[0083] Among them, w i is the weight of each secondary index relative to the zero-level index; the load loss power R of each secondary index i .

[0084] In addition, the present invention provides a power system load loss fault severity quantification system, comprising the following units: a quantification system construction unit, a load loss electricity statistical unit of a secondary indicator, a load loss electricity risk weight calculation unit of a secondary indicator, a load loss electricity acquisition unit of a primary indicator, a load loss electricity risk weight calculation unit of a primary indicator, a load loss electricity calculation unit of a zero-level indicator, and a load loss risk assessment unit;

[0085] The quantification system building unit is used to construct a load loss fault severity quantification system that is divided according to administrative regions and refined layer by layer. The load loss fault severity quantification system uses the provincial load loss quantity as the zero-level indicator. The zero-level indicator includes three first-level indicators: the load reduction of the prefecture-level city power grid, the load reduction of the county-level city power grid, and the load reduction of the county-level power grid. Each first-level indicator includes multiple second-level indicators formed by the load reduction of the power grid in a specific administrative region;

[0086] The load loss electricity statistical unit of the secondary indicator is used to count the load loss electricity of the secondary indicator;

[0087] The secondary indicator load loss electricity risk weight calculation unit is used to calculate the secondary indicator load loss electricity risk weight;

[0088] The first-level indicator load loss power acquisition unit is used to weighted sum the second-level indicator load loss power and the second-level indicator load loss power risk weight to obtain the first-level indicator load loss power;

[0089] The first-level indicator load loss electricity risk weight calculation unit is used to calculate the first-level indicator load loss electricity risk weight;

[0090] The zero-level index load loss electricity calculation unit is used to weighted sum the first-level index load loss electricity and the first-level index load loss electricity risk weight to obtain the zero-level index load loss electricity;

[0091] The load loss risk assessment unit is used to assess the load loss risk according to the load loss electricity of the zero-level indicator.

[0092] Among them, the risk weight of the secondary indicator load loss electricity is a relative weight.

[0093] Among them, the methods for calculating the risk weight of the secondary indicator load loss electricity include the 1-9 point scale method and the 0-2 point three-scale method.

[0094] The calculation formula of the load loss quantity of the zero-level indicator is as follows:

[0095]

[0096] Among them, w i is the weight of each secondary index relative to the zero-level index; the load loss power R of each secondary index i .

[0097] The optional implementation modes of the embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation modes. Within the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical scheme of the embodiments of the present invention, and these simple modifications all belong to the protection scope of the embodiments of the present invention.

Claims

1. A method for quantifying the severity of load loss faults in a power system, characterized in that: The steps include: Step S1: construct a load loss fault severity quantification system divided according to administrative regions and refined layer by layer, wherein the load loss fault severity quantification system uses the provincial load loss quantity as the zero-level indicator, and the zero-level indicator includes three first-level indicators: the load reduction of the prefecture-level city power grid, the load reduction of the county-level city power grid, and the load reduction of the county-level power grid. Each first-level indicator includes multiple second-level indicators formed by the load reduction of the power grid in a specific administrative region; Step S2: Count the load loss power of the secondary indicator; Step S3: Calculate the risk weight of the secondary indicator load loss electricity; Step S4: weighted summing the load loss electricity of the secondary indicator and the risk weight of the load loss electricity of the secondary indicator to obtain the load loss electricity of the primary indicator; Step S5: Calculate the risk weight of the first-level indicator load loss electricity; Step S6: weighted sum of the load loss power of the first-level indicator and the risk weight of the load loss power of the first-level indicator to obtain the load loss power of the zero-level indicator; Step S7: Evaluate the load loss risk according to the load loss power of the zero-level indicator.

2. A method for quantifying the severity of load loss fault in a power system according to claim 1, characterized in that: In step S3, the secondary indicator load loss power risk weight is a relative weight.

3. A method for quantifying the severity of load loss fault in a power system according to claim 1, characterized in that: The methods for calculating the risk weight of the secondary indicator load loss electricity include the 1-9 point scale method and the 0-2 point three-scale method.

4. A method for quantifying the severity of load loss fault in a power system according to claim 1, characterized in that: In step S7, the calculation formula of the load loss power of the zero-level indicator is as follows: Among them, w i is the weight of each secondary index relative to the zero-level index; the load loss power R of each secondary index i .

5. A power system load loss fault severity quantification system, characterized in that: It includes the following units: quantitative system building unit, load loss electricity statistics unit of secondary indicators, risk weight calculation unit of load loss electricity of secondary indicators, load loss electricity acquisition unit of primary indicators, risk weight calculation unit of load loss electricity of primary indicators, load loss electricity calculation unit of zero-level indicators, and load loss risk assessment unit; The quantification system building unit is used to construct a load loss fault severity quantification system that is divided according to administrative regions and refined layer by layer. The load loss fault severity quantification system uses the provincial load loss quantity as the zero-level indicator. The zero-level indicator includes three first-level indicators: the load reduction of the prefecture-level city power grid, the load reduction of the county-level city power grid, and the load reduction of the county-level power grid. Each first-level indicator includes multiple second-level indicators formed by the load reduction of the power grid in a specific administrative region; The load loss electricity statistical unit of the secondary indicator is used to count the load loss electricity of the secondary indicator; The secondary indicator load loss electricity risk weight calculation unit is used to calculate the secondary indicator load loss electricity risk weight; The first-level indicator load loss power acquisition unit is used to weighted sum the second-level indicator load loss power and the second-level indicator load loss power risk weight to obtain the first-level indicator load loss power; The first-level indicator load loss electricity risk weight calculation unit is used to calculate the first-level indicator load loss electricity risk weight; The zero-level index load loss electricity calculation unit is used to weighted sum the first-level index load loss electricity and the first-level index load loss electricity risk weight to obtain the zero-level index load loss electricity; The load loss risk assessment unit is used to assess the load loss risk according to the load loss electricity of the zero-level indicator.

6. A method for quantifying the severity of load loss fault in a power system according to claim 5, characterized in that: The risk weight of the secondary indicator load loss electricity is a relative weight.

7. A method for quantifying the severity of load loss fault in a power system according to claim 5, characterized in that: The methods for calculating the risk weight of the secondary indicator load loss electricity include the 1-9 point scale method and the 0-2 point three-scale method.

8. A method for quantifying the severity of load loss fault in a power system according to claim 5, characterized in that: The calculation formula of the load loss quantity of the zero-level indicator is as follows: Among them, w i is the weight of each secondary index relative to the zero-level index; the load loss power R of each secondary index i .

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