CN108717597B

CN108717597B - Grid engineering operation benefit evaluation method and system for optimizing grid structure

Info

Publication number: CN108717597B
Application number: CN201810367072.8A
Authority: CN
Inventors: 张恒; 郑燕; 雷体钧; 温卫宁; 汪亚平; 易文飞; 邵黎; 李培栋; 翟树军; 徐玉杰; 李如萍; 吕岳; 李士亮
Original assignee: State Grid Tianjin Electric Power Co Ltd; State Grid Economic and Technological Research Institute
Current assignee: State Grid Tianjin Electric Power Co Ltd; State Grid Economic and Technological Research Institute
Priority date: 2018-04-23
Filing date: 2018-04-23
Publication date: 2021-12-07
Anticipated expiration: 2038-04-23
Also published as: CN108717597A

Abstract

The invention relates to a power grid engineering operation benefit evaluation method and system for optimizing a grid structure, including the following contents: collecting actual operating power data to be evaluated; and evaluating the power grid engineering project efficiency of the optimized grid structure according to the collected power data ; Evaluate the effect of the power grid engineering project of the optimized grid structure according to the collected power data; evaluate the project safety of the optimized grid structure project according to the collected power data, and comprehensively consider the project efficiency, project effect and project safety. Comprehensive evaluation of the operation effect of optimizing the grid structure project.

Description

Grid engineering operation benefit evaluation method and system for optimizing grid structure

Technical Field

The invention relates to a power grid engineering operation benefit evaluation method and system for optimizing a grid structure, and relates to the technical field of power grid transmission.

Background

At present, two methods are generally used for evaluating the operation benefit of a power grid engineering project, and one method is to evaluate the operation benefit of the power grid engineering project with all functional types by adopting the same index system.

Because the functions of the power transmission and transformation project in the power grid are different, the evaluation indexes and the evaluation standards of the power transmission and transformation project are different, for example, the safety requirement of the power supply project of the electric railway is high, the requirement on the load rate is relatively low, the requirement on the load rate of the power demand project is high, all projects are evaluated by adopting uniform indexes and standards, the functional attribute characteristics of the project are ignored, a targeted suggestion cannot be provided for the subsequent construction of the project, and the evaluation method cannot fully reflect whether the fundamental objective of the project construction is realized; the other type is that the power grid engineering project is divided into public network engineering, special power transmission and transformation engineering and networking engineering, and different evaluation indexes are respectively set for each engineering to evaluate the operating benefits of the project from the aspects of space and physical level of the engineering in the power grid. In addition, the indexes related in the two methods are not set with evaluation standards, and the subjectivity of the evaluation process is strong.

In summary, no research has been conducted so far to construct an evaluation system for meeting the power consumption requirement in a targeted manner from the perspective of different functions of engineering project systems, provide evaluation indexes and clarify evaluation standards.

Disclosure of Invention

In view of the above problems, the present invention aims to provide a grid project operation benefit evaluation method and system for optimizing a grid structure, which can accurately evaluate a grid project from the perspective of different engineering system functions.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a grid engineering operation benefit evaluation method for optimizing a grid structure, which includes the following steps: acquiring actual operation power data to be evaluated; evaluating the power grid engineering project performance of the optimized grid structure according to the collected power data, wherein project performance evaluation indexes comprise improvement of contribution performance of the grid structure, a bayonet current check ratio and an average power supply radius difference value; evaluating the power grid engineering project effect of the optimized grid structure according to the collected power data, wherein project effect evaluation indexes comprise the maximum load rate of an engineering transformer, the average load rate of the engineering transformer, the maximum load rate of an engineering line, the average load rate of the engineering line, overhead line loss, main transformer loss, the power factor at the moment of maximum load, the power factor at the moment of minimum load and capacity-to-load ratio;

evaluating the project safety of the optimized grid structure engineering according to the collected electric power data, wherein the evaluation indexes of the project safety comprise main transformer availability, line availability, bus voltage qualification rate, grid safety accident occurrence times, misoperation and failure times of a relay protection and stability device, transformer unplanned outage time, line unplanned outage hours, line unplanned outage frequency and line trip-out rate;

and comprehensively considering the project efficiency, the project effect and the project safety, and comprehensively evaluating the operation effect of the optimized grid structure project.

Further, the efficiency of the power grid engineering project of the optimized grid structure is evaluated according to the collected power data, and the specific evaluation process is as follows:

calculating contribution performance sigma of the change situation of the peripheral power grid connection structure, namely the grid structure before and after the project is put into operation, evaluating the importance of the project according to the sigma, and recording the evaluation result as D₁₁；

Calculating the ratio R of the actual line running current to the line bayonet current_ab：

R_ab＝C_a/C_b

In the formula, C_aFor line running of actual current, C_bFor line-card current, according to R_abThe importance of the process was evaluated and the evaluation result was recorded as D₁₂；

Calculating the difference delta R between the geometric center of the power supply range of the transformer substation and the average value of the boundary before and after the project operation:

in the formula, delta R is the difference between the average power supply radiuses of regional power grids before and after project operation, S is the power supply area of the region where the project is located, N is the total number of the substations of the regional power grids where the project is located before the project operation, project importance evaluation is carried out according to the delta R, and the evaluation result is marked as D₁₃；

Calculating D from the above results₁：D₁＝a₁₁D₁₁+a₁₂D₁₂+a₁₃D₁₃According to D₁Evaluating the effect of the engineering construction on enhancing the optimization capability of the grid structure, wherein a₁₁、a₁₂、a₁₃Respectively contributing performance for improving the grid structure, checking the weight of the ratio and the difference value of the average power supply radius in the performance evaluation, a₁₁+a₁₂+a₁₃＝1。

Further, the specific evaluation process for evaluating the power grid engineering project effect of the optimized grid structure according to the collected power data is as follows:

calculating the maximum load factor mu of the engineering transformer_max,t：μ_max,t＝P_max,t/S_tIn the formula, mu_max,tThe maximum load rate of the transformer is obtained; p_max,tFor the maximum load of the transformer, S_tEvaluating the engineering operation effect according to the interval of the maximum load rate after the transformer is put into operation for a preset time for the rated capacity of the transformer, and recording the evaluation result as D₂₁According to whether the engineering operation effect reaches the expected pair D₂₁Setting the value of (c);

calculating the average load factor mu of the engineering transformer_avg,t：μ_avg,t＝P_avg,t/S_tIn the formula, mu_avg,tThe average load factor of the transformer is obtained; p_avg,tIs the annual average load of the transformer, S_tSetting the age limit time for rated capacity of the transformer and operation of the transformer, evaluating the engineering operation effect according to the interval of the average load rate of the transformer, and recording the evaluation result as D₂₂According to whether the engineering operation effect reaches the expected pair D₂₂Setting the value of (c);

calculating the maximum load rate mu of the line_max,1：μ_max,1＝P_max,1/S₁In the formula, mu_max,1The maximum load rate of the line; p_max,lFor the maximum load on the line, S_lEvaluating the engineering operation effect according to the interval of the maximum load rate of the line after the line is put into operation for setting the age limit for the rated capacity of the line, and recording the evaluation result as D₂₃According to whether the engineering operation effect reaches the expected pair D₂₃Setting the value of (c);

calculating the average load factor mu of the line_avg,1：μ_avg,1＝P_avg,1/S₁In the formula, mu_avg,1Is the average load rate of the line; p_avg,lThe annual average load of the line; s_lA line with rated capacity; after the set time of commissioning, evaluating the engineering operation effect according to the line average load percentage interval, and recording the evaluation result as D₂₄According to whether the engineering operation effect reaches the expected pair D₂₄Setting the value of (c);

calculating overhead line loss Q_l,l：Q_l.l＝Q_in-Q_outIn the formula, Q_inFor input of electric power, Q, to the transformer_outEvaluating the engineering operation effect according to the overhead line loss for the output electric quantity of the transformer, and recording the evaluation result as D₂₅According to whether the engineering operation effect reaches the expected pair D₂₅Setting the value of (c);

calculating main transformer loss Q_l,t，Q_l.t＝Q_in-Q_outIn the formula Q_inInputting electric quantity for the transformer in unit of MWh; q_outFor the transformer output electric quantity, the engineering operation effect is evaluated according to the main transformer loss, and the evaluation result is recorded as D₂₆；

Calculating the power factor at the moment of maximum load

In the formula, S is the apparent power transmitted by the equipment at the moment of maximum load, P is the active power transmitted by the equipment at the moment of maximum load, Q is the reactive power transmitted by the equipment at the moment of maximum load, the engineering operation effect evaluation is carried out according to the power factor at the moment of maximum load, and the evaluation result is recorded as D₂₇According to whether the engineering operation effect reaches the expected pair D₂₇Setting the value of (c);

calculating the power factor at the moment of minimum load

In the formula, S is apparent power transmitted by the equipment at the moment of minimum load, P is active power transmitted by the equipment at the moment of minimum load, Q is reactive power transmitted by the equipment at the moment of minimum load, engineering operation effect evaluation is carried out according to the power factor at the moment of minimum load, and the evaluation result is recorded as D₂₈According to whether the engineering operation effect reaches the expected pair D₂₈Setting the value of (c);

calculating the ratio Rs of the total capacity of the public transformation equipment of a certain power supply area of the power grid and the power grid with the same voltage class to the corresponding total load after the project is put into operation:

R_s＝∑S_ei/P_max

in the formula, sigma S_eiThe daily maximum load is the maximum load of the voltage class; p_maxEvaluating the total capacity of the transformer substation which is put into operation for the annual maximum load according to the engineering operation effect of Q/GDW 156-2006 in accordance with the urban power grid planning and designing guide rule, and recording the evaluation result as D₂₉According to whether the engineering operation effect reaches the expected pair D₂₉Setting the value of (c);

calculating D from the above index₂According to D₂And evaluating the engineering effect with the comparison result of the preset threshold: d₂＝a₂₁D₂₁+a₂₂D₂₂+a₂₃D₂₃+a₂₄D₂₄+a₂₅D₂₅+a₂₆D₂₆+a₂₇D₂₇+a₂₈D₂₈+a₂₉D₂₉Wherein a is₂₁、a₂₂、a₂₃、a₂₄、a₂₅、a₂₆、a₂₇、a₂₈、a₂₉The maximum load rate of the engineering transformer, the average load rate of the engineering transformer, the maximum load rate of the engineering line and the average load rate of the engineering line are respectivelyThe weight of the average load rate, overhead line loss, main transformer loss, maximum load moment power factor, minimum load moment power factor and capacity-to-load ratio in the efficiency evaluation, a₂₁+a₂₂+a₂₃+a₂₄+a₂₅+a₂₆+a₂₇+a₂₈+a₂₉＝1。

Further, the specific evaluation process for evaluating the project safety of the optimized grid structure engineering according to the collected power data is as follows:

calculating the availability A of the main transformer_T：

In the formula: mu is the forced outage rate, T_rMean time to failure, T_ΣAAccumulating fault-free operating time, T, for the plant_ΣIn order to accumulate the commissioning time, the engineering safety reliability is evaluated according to the availability of the main transformer, and the evaluation result is D₃₁Indicates, according to the degree of engineering safety reliability, the pair D₃₁Determining a value;

calculating line availability A_L：

Wherein u is the forced outage rate, T_rMean time to failure, T_ΣAAccumulating fault-free operating time, T, for the plant_ΣFor accumulating the commissioning time, the engineering safety and reliability are evaluated according to the availability of the line, and the evaluation result is D₃₁Indicates, according to the degree of engineering safety reliability, the pair D₃₂Determining a value;

calculating the qualification rate eta of A-phase voltage of project bus_A：η_A(％)＝(1-T_b/T_Σ) 100% of formula (i), wherein eta_AFor project bus A phase voltage qualification rate, T_bFor voltage out-of-limit accumulated time, T_ΣCounting time for the total operation of the project according to the A phase voltage of the busEvaluating the engineering safety reliability by the qualification rate, and recording the evaluation result as D₃₃According to the degree of engineering safety reliability, pair D₃₃Determining a value;

counting the occurrence frequency J of the grid safety accident_aEvaluating the engineering safety reliability according to the occurrence frequency of the power grid safety accidents, and recording the evaluation result as D₃₄According to the degree of engineering safety reliability, pair D₃₄Determining a value;

calculating the times J of false operation and refusal operation of relay protection and safety device in the project or safety device at other positions in the power grid caused by project operation_JEvaluating the engineering safety reliability according to the misoperation and the failure times of the relay protection and stability device, and recording the evaluation result as D₃₅According to the degree of engineering safety reliability, pair D₃₅Determining a value;

statistics of unplanned transformer outage time sigma T_d.tEvaluating the engineering safety reliability according to the unplanned outage hours of the transformer, and recording the evaluation result as D₃₆According to the degree of engineering safety reliability, pair D₃₆Determining a value;

obtaining the number sigma T of the unplanned shutdown hours of the line_d.lEvaluating the engineering safety reliability according to the unplanned outage hours of the line, and recording the evaluation result as D₃₇According to the degree of engineering safety reliability, pair D₃₇Determining a value;

statistical circuit unplanned outage frequency f_lEvaluating the engineering safety reliability according to the unplanned shutdown frequency of the line, and recording the evaluation result as D₃₈According to the degree of engineering safety reliability, pair D₃₈Determining a value;

calculating the trip rate caused by the external environment or insulation problem of the line operation: λ is M/T, where λ is the trip rate of the line, M is the total number of trips within a statistical period, which are not caused by the capacity of the line or insulation problems, T is the evaluation time, the engineering safety and reliability are evaluated according to the trip rate of the line, and the evaluation result is recorded as D₃₉According to the degree of engineering safety reliability, pair D₃₉Determining a value;

evaluating engineering safety according to the above indexes, and using D as evaluation result₃Represents: d₃＝a₃₁D₃₁+a₃₂D₃₂+a₃₃D₃₃+a₃₄D₃₄+a₃₅D₃₅+a₃₆D₃₆+a₃₇D₃₇+a₃₈D₃₈+a₃₉D₃₉Wherein a is₃₁、a₃₂、a₃₃、a₃₄、a₃₅、a₃₆、a₃₇、a₃₈、a₃₉The weights of 9 indexes of main transformer availability, line availability, bus voltage qualification rate, grid safety accident occurrence frequency, relay protection and safety device misoperation and failure frequency, transformer unplanned outage time, line unplanned outage hours, line unplanned outage frequency and line trip-out rate in safety evaluation are respectively, and a₃₁+a₃₂+a₃₃+a₃₄+a₃₅+a₃₆+a₃₇+a₃₈+a₃₉1 is ═ 1; according to D₃And evaluating whether the engineering safety reliability is qualified or not according to a comparison result with a preset value.

Further, according to the evaluation results of project efficiency, project effect and project safety, the comprehensive evaluation of the operation effect of the power grid project of the cross-province and cross-district reinforced transmission channel comprises the following specific processes:

1) calculating a running effect comprehensive evaluation value, wherein the calculation formula of the running effect comprehensive evaluation is as follows:

D＝a₁D₁+a₂D₂+a₃D₃

wherein, a₁、a₂、a₃Respectively, project efficiency D₁Project effect D₂Project safety D₃Weight of a₁+a₂+a₃＝1；

2) When D is less than the set minimum threshold, the operation effect of the project as the optimized grid structure project is considered to be poor;

when the set minimum threshold value is not more than D and less than the set maximum threshold value, the operation effect of the optimized grid structure of the project is considered to be good;

when D is larger than or equal to the set maximum threshold value, the operation effect of the engineering optimization grid structure is considered to be good.

Further, said a₁、a₂、a₃And solving by adopting a weight solving algorithm combining an index classification reference comparison method and subjective and objective weights.

Further, before calculating the running effect comprehensive evaluation value D, the method further includes:

determination of D₁、D₂、D₃Comment level domain;

for efficiency D₁Evaluating and determining comment grade domain as d₁＝{d₁₁,d₁₂,d₁₃In which d is₁₁Represents importance, d₁₂Representing general importance, d₁₃The representation is not critical;

for effect D₂Evaluation determination of discourse Domain as d₂＝{d₂₁,d₂₂In which d is₂₁Representing satisfaction of the demand, d₂₂Representing an unsatisfied demand;

for safety D₃Evaluation determination of discourse Domain as d₃＝{d₃₁,d₃₂In which d is₃₁Represents pass, d₃₂Is not qualified;

the above qualitative evaluations were converted into numerical values.

In a second aspect, the present invention further provides a grid engineering operation benefit evaluation system for optimizing a grid structure, where the system includes:

the data acquisition module is used for acquiring actual operation power data to be evaluated;

the project efficiency evaluation module is used for evaluating the power grid project efficiency of the optimized grid structure according to the collected power data, and project efficiency evaluation indexes comprise improvement of contribution performance of the grid structure, a bayonet current check ratio and an average power supply radius difference value;

the project effect evaluation module is used for evaluating the power grid project effect of the optimized grid structure according to the collected power data, and project effect evaluation indexes comprise the maximum load rate of an engineering transformer, the average load rate of the engineering transformer, the maximum load rate of an engineering line, the average load rate of the engineering line, overhead line loss, main transformer loss, power factor at the maximum load moment, power factor at the minimum load moment and capacity-to-load ratio;

the project safety evaluation module is used for evaluating the project safety of the optimized grid structure project according to the collected power data, and the evaluation indexes of the project safety include main transformer availability, line availability, bus voltage qualification rate, grid safety accident occurrence times, misoperation and rejection times of relay protection and safety devices, transformer unplanned outage time, line unplanned outage hours, line unplanned outage frequencies and line trip-out rates;

and the comprehensive evaluation module is used for comprehensively considering the project efficiency, the project effect and the project safety and comprehensively evaluating the operation effect of the optimized grid structure engineering.

Due to the adoption of the technical scheme, the invention has the following advantages: 1. the invention provides a power grid project operation benefit evaluation method aiming at optimizing a grid structure from the aspect of project system function positioning, and solves the problem that the evaluation is difficult after the project is put into operation. 2. According to the invention, the power grid project operation evaluation index of the optimized grid structure is established from three dimensions of efficiency, effect and safety, the maximum function and the actual function of a newly-built project in a power grid can be directly reflected, and the contribution of the project to the optimization of the grid structure is reflected. 3. The invention provides an evaluation index which is in accordance with the original intention of engineering construction aiming at the optimization of grid structure engineering, so that the evaluation result can truly reflect whether the actual operation benefit of the engineering meets the construction requirement or not, and the problem that the evaluation content is comprehensive but the pertinence is not strong is avoided. 4. The invention adopts a weight solving algorithm based on the combination of an index classification reference comparison method and subjective and objective weights, is used for determining the weight aggregation calculation process of subjective and objective influence factors in combined evaluation indexes, can solve the problem that the application of an analytic hierarchy process is often limited in practice in multiple stages of dimension constraints, and realizes accurate weight values under the condition of multi-index evaluation. 5. The method has the advantages of strong pertinence of evaluation indexes, clear evaluation standard and scientific weight determination method, and the evaluation result directly acts on the future operation management work of the project, thereby having an important guiding function on the construction management meeting the power consumption requirement in the future.

Drawings

FIG. 1 is a schematic flow chart of a power grid engineering operation benefit evaluation method for optimizing a grid structure of the invention;

FIG. 2 is a schematic flow chart of the weight solving algorithm based on the combination of index classification reference comparison method (ICRC) and subjective and objective weights.

Detailed Description

The present invention is described in detail below with reference to the attached drawings. It is to be understood, however, that the drawings are provided solely for the purposes of promoting an understanding of the invention and that they are not to be construed as limiting the invention.

The method evaluates the operation effect of the power grid project of the optimized grid structure from three dimensions of efficiency, effect and safety.

Efficiency: the setting of the efficiency evaluation index aims to reflect the maximum effect that the engineering optimization network structure can play in the power grid system of the engineering after the engineering is put into operation, and whether the capability of the engineering construction mainly pointing to the optimization of the regional power grid structure is obvious or not is the evaluation result.

The effect is as follows: the setting of the effect evaluation index aims to reflect the actual operation condition in the engineering operation process, and whether the actual effect exerted by the operation of the evaluation result mainly pointing to the engineering in the aspect of optimizing the grid structure meets the construction requirement or not.

Safety: the setting of the safety evaluation index aims to reflect the conditions of the engineering in the aspects of safety, reliability and the like as public infrastructure, and the evaluation result mainly points to whether the safety and reliability of the engineering meet the basic requirements of the power grid engineering.

Example 1

As shown in fig. 1, the method for evaluating the operation benefit of the grid project with an optimized grid structure provided by the invention comprises the following steps:

1. and collecting actual operation power data needing to be evaluated.

2. Evaluating the power grid engineering project performance of the optimized grid structure according to the collected power data, wherein project performance evaluation indexes comprise improvement of contribution performance of the grid structure, a bayonet current check ratio and an average power supply radius difference value, and the specific evaluation process of each evaluation index on the project performance is as follows:

1) improving contribution performance of grid structure

Calculating the change condition of the wiring structure of the peripheral power grid before and after the project is put into operation, evaluating the contribution effect of the project on improving the grid structure and improving the power supply reliability and the load transfer capability. Double radiation is considered to be equivalent to a single ring network, a single chain, and a double ring network is equivalent to a double chain.

Sigma (-1 or 0 or 1)

In the formula, sigma is used for improving the contribution performance of the grid structure, engineering importance evaluation is carried out on sigma, and the evaluation result is recorded as D₁₁. When the project is put into operation, sigma is 1, the grid structure is changed from radiation to a ring network or a chain, the project plays a role in grid optimization, and D₁₁100; when σ is 0, the grid structure is not changed in engineering construction, D₁₁60; when sigma is-1, the net frame structure is considered to be changed from ring net or chain type to radiation, the engineering has weakening effect on the net frame structure, D₁₁＝40。

2) Checking ratio of bayonet current

Calculating the ratio R of the actual line running current to the line bayonet current_abAnd evaluating the maximum limit level of current supply when the project is in normal operation. The current of the line bayonet is determined by the minimum value of rated capacity of equipment such as a line section, switches at two ends of the line, a mutual inductor, a wave trap and the like.

R_ab＝C_a/C_b

In the formula, C_aFor line running of actual current, C_bIs a line card port current. To R_abThe engineering importance evaluation is carried out according to percentage value intervals, and the evaluation result is recorded as D₁₂. When R is_abBetween 50% and 90%, considered important for engineering, D₁₂100; when R is_abBetween 30% and 50%, considered important, D₁₂80; when R is_abLess than 30%, the engineering is considered less important, D₁₂40; when R is_abGreater than 90%Considering that there is a design defect in the engineering, the efficiency performance exceeds the safety standard, D₁₂＝0。

3) Average power supply radius difference

And calculating the difference delta R between the geometric center of the power supply range of the transformer substation and the average value of the boundary before and after the project is put into operation, and evaluating the condition of shortening the radius of the project on the regional power grid.

In the formula, delta R is the difference of the average power supply radius of the regional power grid before and after the project operation, and the unit is km; s is the power supply area of the area where the project is located, and the unit is km²N is the total number of the regional power grid transformer substations where the engineering is located before operation, engineering importance evaluation is carried out on the delta R, and the evaluation result is recorded as D₁₃. When the delta R is more than 5km, the effect of engineering on shortening the average power supply radius is considered to be remarkable, D₁₃100; when the delta R is between 3 and 5km, the effect of the engineering on shortening the average power supply radius is considered to be obvious, and D₁₃80; delta R is between 1 and 3km, and the engineering effect on shortening the average power supply radius is considered to be general, D₁₃60; delta R is less than 1km, the effect of the project on shortening the average power supply radius is not considered obvious, D₁₃＝40。

4) Determination of engineering performance evaluation index weight

The method adopts a weight solving algorithm based on the combination of an index classification reference comparison method (ICRC) and subjective and objective weights to solve the determination of the index weight, and can determine a₁₁、a₁₂、a₁₃Wherein, a₁₁、a₁₂、a₁₃Respectively contributing performance for improving the grid structure, checking the ratio of the bayonet current and the weight of 3 indexes of the difference value of the average power supply radius in the performance evaluation, and a₁₁+a₁₂+a₁₃＝1。

Evaluating whether the effect of the engineering construction on enhancing the optimization capability of the grid structure is obvious or not according to the efficiency calculation result, and using D as the evaluation result₁Represents:

D₁＝a₁₁D₁₁+a₁₂D₁₂+a₁₃D₁₃…a₁₉D₁₉

when the evaluation result D₁When the construction time is more than or equal to 80, the construction of the project is considered to have obvious optimization capacity for reinforcing the grid structure; when the evaluation result is 60. ltoreq.D₁When the number is less than 80, the construction of the project is considered to have general optimization capability for reinforcing the grid structure; when the evaluation result D₁If the number is less than 60, the optimization capability of the construction of the project on the reinforced grid structure is considered to be poor.

3. Evaluating the power grid engineering project effect of the optimized grid structure according to the collected power data, wherein project effect evaluation indexes comprise the maximum load rate of an engineering transformer, the average load rate of the engineering transformer, the maximum load rate of an engineering line, the average load rate of the engineering line, overhead line loss, main transformer loss, the power factor at the moment of maximum load, the power factor at the moment of minimum load and capacity-to-load ratio, and the specific evaluation process of each evaluation index on the project effect is as follows:

1) maximum load factor of engineering transformer

Calculating the maximum load factor mu of the engineering transformer_max,tAnd evaluating the maximum load condition of the engineering transformer.

μ_max,t＝P_max,t/S_t

In the formula, P_max,tThe maximum load of the transformer, unit MW; s_tThe rated capacity of the transformer is in MVA.

After the transformer is put into operation for one year, evaluating the engineering operation effect according to the percentage interval of the maximum load rate, and recording the evaluation result as D₂₁. When mu is_max,tWhen the maximum load condition of the engineering transformer is more than 40 percent, the maximum load condition of the engineering transformer is considered to basically realize the planning target, the selection of the main transformer capacity is reasonable, the engineering operation effect meets the expected requirement, and D₂₁100; otherwise, the expected requirements are not met, D₂₁＝50。

2) Average load factor of engineering transformer

Calculating the average load factor mu of the engineering transformer_avg,tAnd evaluating the average load condition of the engineering transformer.

μ_avg,t＝P_avg,t/S_t

In the formula, mu_avg,tThe average load factor of the transformer is obtained; p_avg,tThe unit MW is the annual average load of the transformer; s_tThe rated capacity of the transformer is in MVA. After the transformer is put into operation for one year, evaluating the engineering operation effect according to the average load percentage interval of the transformer, and recording the evaluation result as D₂₂. When mu is_avg,tWhen the load is more than or equal to 50 percent, the engineering transformer is considered to be overloaded for a long time, the operation effect does not meet the expected requirement, and D₂₂50; when mu is_avg,tBetween 25% and 50%, considering that the engineering transformer has reasonable load condition, the engineering operation effect meets the expected requirement, D₂₂100; when mu is_avg,tWhen the load is less than or equal to 25 percent, the engineering transformer is considered to be light-load, the operation effect does not meet the expected requirement, and D₂₂＝50。

3) Line maximum load rate

Calculating the maximum load rate mu of the line_max,1And evaluating the maximum load condition of the engineering line.

μ_max,1＝P_max,1/S₁

In the formula, mu_max,1The maximum load rate of the line; p_max,lThe maximum load of the line, unit MW; s_lFor line rated capacity, in MVA. And after the line is put into operation for one year, evaluating the engineering operation effect according to the percentage interval of the maximum load rate of the line, and recording the evaluation result as D₂₃. When mu is_max,1When the maximum load rate of the regional power grid line is more than 60% of the average value of the maximum load rates of the regional power grid line with the same voltage class, the maximum load condition of the engineering line is considered to basically achieve the planning target, the line type selection is reasonable, the engineering operation effect is considered to meet the expected requirement, and D₂₃100; otherwise, the engineering operation effect is considered to be not in accordance with the expected requirement, D₂₃＝50。

4) Average load factor of line

Calculating the average load factor mu of the line_avg,1And evaluating the average load condition of the engineering line.

μ_avg,1＝P_avg,1/S₁

In the formula, mu_avg,1Is the average load rate of the line; p_avg,lThe annual average load of the line; s_lIs the rated capacity of the line. And after the line is put into operation for one year, evaluating the engineering operation effect according to the line average load percentage interval, and recording the evaluation result as D₂₄. When mu is_avg,lWhen the average load rate of the regional power grid line is more than 60 percent of the average load rate of the regional power grid line with the same voltage level, the average load condition of the engineering line is considered to basically achieve the planning target, the line type selection is reasonable, the engineering operation effect is considered to meet the expected requirement, and D₂₄100; otherwise, the engineering operation effect is considered to be not in accordance with the expected requirement, D₂₄＝50。

5) Overhead line loss

Calculating overhead line loss Q_l,lAnd evaluating the reasonability of the overhead line loss.

Q_l.l＝Q_in-Q_out

In the formula, Q_l,lUnit MWh; q_inInputting electric quantity for the transformer in unit of MWh; q_outThe output electric quantity of the transformer is unit MWh. Evaluating the engineering operation effect according to the overhead line loss, and recording the evaluation result as D₂₅. When Q is_l,lWhen the average loss of the overhead line is less than or equal to the average loss of the overhead line with the same voltage class, considering that the loss of the overhead line is reasonable, and the engineering operation effect meets the expected requirement, D₂₅100; when Q is_l,lWhen the average loss of the overhead line is larger than the average loss of the overhead line with the same voltage class, the overhead line is considered to be seriously lost, the engineering operation effect does not meet the expected requirement, and D₂₅＝50。

6) Main transformer loss

Calculating main transformer loss Q_l,tAnd evaluating the rationality of the main transformer loss.

Q_l.t＝Q_in-Q_out

In the formula, Q_l,tThe unit MWh is the main transformer loss; q_inInputting electric quantity for the transformer in unit of MWh; q_outThe output electric quantity of the transformer is unit MWh. Evaluating the engineering operation effect according to the main transformer loss, and recording the evaluation result as D₂₆. When Q is_l,tWhen the average loss of the transformer with the same voltage class and the same capacity is less than or equal to the average loss of the transformer with the same voltage class and the same capacity,considering the reasonable loss of the main transformer, D₂₆100; when Q is_l,tWhen the average loss of the transformer with the same voltage class and the same capacity is larger than the average loss of the transformer with the same voltage class, the main transformer loss is considered to be serious, D₂₆＝50。

7) Power factor at time of maximum load

Calculating the power factor at the moment of maximum load

Evaluating whether project capacitive reactive configuration is sufficient:

in the formula, S is the apparent power transmitted by the device at the time of maximum load, and the unit is MVA, P is the active power transmitted by the device at the time of maximum load, and the unit is MW, Q is the reactive power transmitted by the device at the time of maximum load, and the unit is MVar.

And evaluating the engineering operation effect according to the power factor at the maximum load moment, and recording the evaluation result as D₂₇. When in use

When the reactive power is more than or equal to 0.95, the project capacitive reactive power configuration is enough, the contribution to reducing the power grid loss and improving the power quality is obvious, the engineering operation effect meets the expected requirement, and D₂₇100; when in use

When the reactive configuration is less than 0.95, the project capacitive reactive configuration or the actual investment is not enough, the regulation requirement is not met, the engineering operation effect does not meet the expected requirement, and D₂₇＝50。

8) Power factor at minimum load moment

Calculating the power factor at the moment of minimum load

Evaluating whether the project inductive reactive configuration is sufficient:

in the formula, S is the apparent power transmitted by the minimum load time device, and the unit is MVA, P is the active power transmitted by the minimum load time device, and the unit is MW, Q is the reactive power transmitted by the minimum load time device, and the unit is MVar.

And evaluating the engineering operation effect according to the power factor at the minimum load moment, and recording the evaluation result as D₂₈When is coming into contact with

When the value is between 0.92 and 0.95, the inductive reactive power configuration of the project is reasonable, the operation switching is timely, the engineering operation effect meets the expected requirement, and D₂₈100; when in use

When the configuration capacity of the project reactive compensation device is less than 0.92 or more than 0.95, the project reactive compensation device is considered to be unreasonable in configuration capacity or not timely in switching, the regulation requirement is not met, the project operation effect does not meet the expected requirement, and D₂₈＝50。

9) Capacity to load ratio

And calculating the ratio Rs of the total capacity of the public power transformation equipment of the power grid in a certain power supply area and the power grid of the same voltage class to the corresponding total load (grid supply load) after the project is put into operation, and evaluating the rationality of the planning and designing of the power transformation capacity of the power grid.

R_s＝∑S_ei/P_max

Wherein Rs is a capacity-carrying ratio; sigma S_eiThe daily maximum load is the maximum load of the voltage class, and the unit MW is the maximum load of the voltage class; p_maxTo the voltage, etcTotal capacity in MVA of the substation put into operation on the annual maximum load day. The evaluation standard refers to the urban power grid planning and design guide (Q/GDW 156-2006), and the evaluation result is recorded as D₂₉. Wherein, 500kV and above are calculated according to a provincial power grid, 330 kV and 220kV are calculated according to a local-city power grid, and 110 kV and 35 kV are calculated according to a county-level power grid. When Rs meets the guide rule for urban electric power network planning and design (Q/GDW 156-2006), D₂₉When Rs does not meet the guide for urban Power grid planning and design (Q/GDW 156-₂₉＝0。

10) Determination of project effect evaluation index weight

The method adopts a weight solving algorithm based on the combination of an index classification reference comparison method and subjective and objective weights to solve the determination of the index weight, and can determine a₂₁、a₂₂、a₂₃、a₂₄、a₂₅、a₂₆、a₂₇、a₂₈、a₂₉Wherein, a₂₁、a₂₂、a₂₃、a₂₄、a₂₅、a₂₆、a₂₇、a₂₈、a₂₉Respectively weighting 9 indexes of the maximum load rate of the engineering transformer, the average load rate of the engineering transformer, the maximum load rate of the engineering line, the average load rate of the engineering line, the loss of the overhead line, the loss of the main transformer, the power factor at the maximum load moment, the power factor at the minimum load moment and the capacity-to-load ratio in the efficiency evaluation, and a₂₁+a₂₂+a₂₃+a₂₄+a₂₅+a₂₆+a₂₇+a₂₈+a₂₉＝1。

Evaluating whether the operation of the project meets the construction requirements in the aspect of optimizing the grid structure of the area according to the effect calculation result, wherein the evaluation result is D₂And (4) showing.

D₂＝a₂₁D₂₁+a₂₂D₂₂+a₂₃D₂₃+a₂₄D₂₄+a₂₅D₂₅+a₂₆D₂₆+a₂₇D₂₇+a₂₈D₂₈+a₂₉D₂₉

When the evaluation result D₂When the operation time is more than or equal to 60, the operation of the project is considered to be in the optimization of the grid structure to meet the requirement; when the evaluation result D₂If the number is less than 60, the operation of the engineering is considered to be not satisfied when the grid structure is optimized.

4. Evaluating the project safety of the optimized grid structure engineering according to the collected power data, wherein the evaluation indexes of the project safety comprise main transformer availability, line availability, bus voltage qualification rate, grid safety accident occurrence frequency, misoperation and failure frequency of a relay protection and stability device, transformer unplanned outage time, line unplanned outage hours, line unplanned outage frequency and line trip-out rate, and the specific evaluation process of each evaluation index on the project safety is as follows:

1) availability of main transformer

Calculating the availability A of the main transformer_TEvaluation of the capacity of the transformer for continuous use:

in the formula: a. the_TThe availability of the main transformer is obtained; mu is forced outage rate, unit times/year; t is_rThe mean time for repairing the fault is unit hour/time; t is_ΣAAccumulating the fault-free working time for the equipment in unit hour; t is_ΣIn order to accumulate the commissioning time, the unit hour, if the project relates to many main transformers, simplify and calculate and take each main transformer minimum. Evaluating the engineering safety reliability according to the availability of the main transformer, and using D as the evaluation result₃₁Is shown when A_TWhen the average value of the availability of the same type of products of the regional power grid is more than or equal to the average value of the availability of the same type of products, the transformer is considered to have good continuous use capability, excellent engineering safety and reliability and D₃₁100; when A is_TWhen the average value of the availability of the same type of products of the regional power grid is smaller than the average value of the availability of the same type of products, the transformer is considered to have weak continuous use capability, the quality of the transformer has defects, and D₃₁＝50。

2) Availability of lines

Calculating line availability A_LAnd evaluating the continuous use capability of the line.

Wherein u is the forced outage rate, unit times/year; t is_rThe mean time for repairing the fault is unit hour/time; t is_ΣAAccumulating the fault-free working time for the equipment in unit hour; t is_ΣTo accumulate commissioning time in hours. Evaluating the engineering safety reliability according to the availability of the line, and using D as the evaluation result₃₂Is shown when A_LWhen the average value of the availability of the same type of lines of regional power grids is more than or equal to the average value, the continuous use capability of the lines is considered to be good, the engineering safety and reliability are good, and D₃₂100; when A is_TWhen the average value of the availability of the same type of line of the regional power grid is less than the average value of the availability of the same type of line, the line is considered to have weaker continuous use capability, the engineering safety and reliability are unqualified, and D₃₂＝50。

3) Bus voltage qualification rate

Calculating the qualification rate eta of A-phase voltage of project bus_AAnd evaluating the voltage quality of the project:

η_A(％)＝(1-T_b/T_Σ)*100％

in the formula eta_AFor project bus A phase voltage qualification rate, T_bThe unit hour is the voltage out-of-limit accumulated time; t is_ΣThe statistical time is the total run of the project in hours.

Evaluating the engineering safety reliability according to the qualification rate of the A-phase voltage of the bus, and recording the evaluation result as D₃₃. When eta_AWhen the voltage is more than or equal to 99.99 percent, the project bus voltage qualification rate is considered to be good, the engineering safety and reliability are excellent, and D₃₃100; when eta_AWhen the voltage is between 99.95 and 99.99 percent, the voltage qualification rate of the project bus is considered to be qualified, the engineering safety and reliability are considered to be excellent, and D₃₃100; when eta_AWhen the voltage is less than or equal to 99.95 percent, the project bus voltage qualification rate is considered to be low, the engineering safety and reliability are unqualified, D₃₃＝50。

4) Number of occurrence of power grid safety accidents

Statistics of grid securityNumber of occurrences of this event J_aAnd evaluating the safe operation level of the project.

Evaluating the engineering safety reliability according to the occurrence frequency of the power grid safety accidents, and recording the evaluation result as D₃₄. Compared with the regulations for emergency handling and investigation handling of electric power safety accidents, when no safety accident occurs in a project, the project is considered to have no influence on the safety of a power grid, the engineering safety and reliability are excellent, and D₃₄100; when the accident below the common accident happens to the project, the project is considered to form certain threat to the safe operation of the power grid, the engineering safety and reliability are excellent, and D₃₄70; when a particularly major accident, a major accident and a major accident occur, the project is considered to have serious damage to the safe operation of the power grid, the engineering safety and reliability are unqualified, and D₃₄＝0。

5) False operation and failure operation times of relay protection and safety device

Calculating the times J of false operation and refusal operation of relay protection and safety device in the project or safety device at other positions in the power grid caused by project operation_JAnd evaluating the accuracy of actions of the relay protection and stability device and the influence on the safe and stable operation of the power grid.

Evaluating the engineering safety reliability according to the misoperation and the failure times of the relay protection and stability device, and recording the evaluation result as D₃₅. When J is_JWhen the value is equal to 0, the project has no influence on the safe and stable operation of the power grid, the engineering safety and reliability are considered to be good, and D₃₅100; when J is_JWhen the value is more than or equal to 1, the condition that the project has large influence on the safe and stable operation of the power grid is shown, the engineering safety and reliability are considered to be unqualified, and D₃₅＝50。

6) Unplanned downtime of transformer

Statistics of unplanned transformer outage time sigma T_d.tAnd evaluating the capability of the transformer for maintaining safe and stable operation.

Evaluating the engineering safety reliability according to the unplanned outage hours of the transformer, and recording the evaluation result as D₃₆. When sigma T_d.tLess than the mean value of the unplanned shutdown time of the regional transformer, the project transformer is considered to have good capability of keeping safe and stable operation, and the project transformer is not damaged by the heat of the heat exchangerExcellent in safety and reliability, D₃₆100; when sigma T_d.tThe mean value of the unplanned shutdown time of the regional transformer is larger than or equal to the mean value of the unplanned shutdown time of the regional transformer, the project transformer is considered to have poor capability of maintaining safe and stable operation, the engineering safety and reliability are unqualified, D₃₆＝50。

7) Number of unplanned outage hours of line

Number of unplanned line outage hours ∑ T_d.lAnd evaluating the capability of the line to maintain safe and stable operation.

Evaluating the engineering safety reliability according to the unplanned outage hours of the line, and recording the evaluation result as D₃₇. When sigma T_d.lLess than the mean value of the unplanned shutdown time of the regional line, good capability of maintaining safe and stable operation of the project line, excellent engineering safety and reliability, D₃₇100; when sigma T_d.lThe mean value of the unplanned shutdown time of the regional line or more is considered as the poor capability of the project line for maintaining safe and stable operation, the engineering safety and reliability are unqualified, D₃₇＝50。

8) Frequency of unplanned outages of line

Statistical circuit unplanned outage frequency f_lAnd evaluating the capability of the line to maintain safe and stable operation.

Evaluating the engineering safety reliability according to the unplanned shutdown frequency of the line, and recording the evaluation result as D₃₈. When f is_lLess than the mean value of the unplanned shutdown frequency of the regional line, good capability of maintaining safe and stable operation of the project line, good engineering safety and reliability, D₃₈100; when f is_lThe mean frequency of unplanned shutdown of the regional lines or more is considered as the capacity of maintaining safe and stable operation of the project line is poor, the engineering safety and reliability are unqualified, D₃₈＝50。

9) Line trip rate

And calculating the tripping rate lambda caused by the external environment or insulation problem of the line operation, and evaluating the safe operation capacity of the line to the environmental change.

λ＝M/T

In the formula, lambda is the non-intrinsic tripping rate of the circuit, unit times/year; m is within the statistical period, non-causeThe total number of trips caused by the capacity of the line or insulation problems is expressed in units of times; t is evaluation time in years. Evaluating the engineering safety reliability according to the line trip rate, and recording the evaluation result as D₃₉. When lambda is less than 1, the safe operation capability of the circuit for coping with environmental changes is considered to be good, the engineering safety and reliability are excellent, and D₃₉100; when lambda is between 1 and 3, the safe operation capability of the line for coping with environmental change is considered to be general, the engineering safety and reliability are excellent, and D₃₉100; when the lambda is more than or equal to 3, the safe operation capability of the line for coping with the environmental change is considered to be poor, the engineering safety reliability is unqualified, and D₃₉＝50。

10) Determination of project safety evaluation index weight

The method for determining the index weight adopts a weight solving algorithm based on the combination of an index classification reference comparison method and subjective and objective weights to solve, and can obtain a₃₁、a₃₂、a₃₃、a₃₄、a₃₅、a₃₆、a₃₇、a₃₈、a₃₉A determined weight value, wherein₃₁、a₃₂、a₃₃、a₃₄、a₃₅、a₃₆、a₃₇、a₃₈、a₃₉The weights of 9 indexes of main transformer availability, line availability, bus voltage qualification rate, grid safety accident occurrence frequency, relay protection and safety device misoperation and failure frequency, transformer unplanned outage time, line unplanned outage hours, line unplanned outage frequency and line trip-out rate in safety evaluation are respectively, and a₃₁+a₃₂+a₃₃+a₃₄+a₃₅+a₃₆+a₃₇+a₃₈+a₃₉＝1。

Evaluating whether the engineering safety reliability is qualified according to the safety calculation result, wherein the evaluation result is D₃And (4) showing.

D₃＝a₃₁D₃₁+a₃₂D₃₂+a₃₃D₃₃+a₃₄D₃₄+a₃₅D₃₅+a₃₆D₃₆+a₃₇D₃₇+a₃₈D₃₈+a₃₉D₃₉

When the evaluation result D₃When the safety reliability of the engineering operation is more than or equal to 60, the basic requirements of the power grid engineering are considered to be met in the aspect of safety reliability of the engineering operation; when the evaluation result D₃When the time is less than 60, the operation of the project is considered to be not in accordance with the basic requirements of the power grid project in terms of safety and reliability.

5. And comprehensively considering the project efficiency, the project effect and the project safety, and comprehensively evaluating the operation effect of the optimized grid structure project.

D＝a₁D₁+a₂D₂+a₃D₃

wherein, a₁、a₂、a₃Respectively is efficacy D₁Effect D₂Safety D₃And define a₁+a₂+a₃And (4) solving by adopting a weight solving algorithm based on the combination of an index classification reference comparison method and the subjective and objective weights, wherein the weight solving algorithm is 1.

2) Determination of D₁、D₂、D₃Comment level discourse

for safety D₃Evaluation determination of discourse Domain as d₃＝{d₃₁,d₃₂In which d is₃₁Represents pass, d₃₂Indicating a failure.

And converting the qualitative evaluation into numerical values, and obtaining the numerical values respectively by the equivalent values corresponding to the three types of membership conversion. To pull the score span between different qualitative judgments, the following three sets of score correspondences are set:

substituting the comprehensive evaluation formula D ═ a₁D₁+a₂D₂+a₃D₃

When D is less than 60, the project is considered to have poor operation effect as the optimized grid structure project, and the efficiency D is determined₁Effect D₂Safety D₃Specifically analyzing the reason of poor operation effect and developing targeted improvement measures.

When D is more than or equal to 60 and less than 80, the optimized grid structure of the engineering is considered to have good operation effect and certain safety and stability, the construction of the engineering has the function of optimizing the grid structure, and the operation of the engineering realizes the function of optimizing the local grid structure to a certain extent. Should be based on efficacy D₁Effect D₂Safety D₃The evaluation result of (2) specifically analyzes the problems existing in the aspect of operation effect, and develops targeted improvement measures.

When D is larger than or equal to 80, the operation effect of the engineering optimization grid structure is good, the engineering optimization grid structure has good safety and stability, the construction of the engineering greatly enhances the structural rationality of the regional power grid, and the function of optimizing the regional power grid structure is fully realized by the operation of the engineering.

In the above embodiment, in order to accurately and comprehensively describe the importance of the evaluation index quantitatively, improve the subjective weight calculation process based on the preference index of the decision maker in the decision logic process in the conventional evaluation method, and according to the first impression effect in decision center, the invention provides a weight solving algorithm based on the combination of an index classification reference comparison method and subjective and objective weights to solve, the subjective weight is determined by the expert experience preference, objective data analysis uses various classical data analysis evaluations, and the combination weight considering the evaluation data characteristics is obtained by normalization formula processing, so that the determination of reasonable weight values under the evaluation of the index number within 20 can be realized, and the specific principle is as follows:

as shown in fig. 2, it is assumed that the samples to be evaluated have i indexes χ whose weights need to be determined, j is not greater than 20, and the evaluated weight vector is W ═ W₁,w₂...,w_j]^TThe specific process for solving the evaluation weight W is as follows:

1) preprocessing the index data, specifically:

1.1) eliminating index abnormal points, specifically adopting the index deviation average value plus two times of standard deviation mu +2 sigma as a sample x for judging whether the index value is abnormal or not_outlierThe standard of (2).

In the formula, μ represents a sample mean value, and σ represents a sample standard deviation.

1.2) index reconciliation treatment

According to the comprehensive evaluation theory, the indexes may belong to three types: "very Large" index X_maxThe "centered" index X_mid"ultra small" index X_min. In order to make the evaluation result comparable, firstly, the mathematical change is performed on the index, namely the index is subjected to the consistency processing, and specifically, the method comprises the following steps:

(1) if X belongs to the extremely small index, taking the reciprocal of the index X as the value e for the coincidence:

(2) if X belongs to the middle type index, taking the comparison result of the index X and the maximum value U and the minimum value U of the optimal range as a consistent value e:

1.3) dimensionless of the index

If the dimensions and the magnitude orders of a plurality of evaluation indexes are different, the indexes need to be subjected to mathematical transformation treatment firstly, so that the indexes are subjected to non-dimensionalization and then are evaluated continuously, and the method specifically comprises the following steps:

in the formula, x_ijValue of j index representing ith sample, M_j＝max{x_ij}，m_j＝min{x_ij}，e_ij∈[0,1]. If the index value is a fixed value, the index needs to be removed.

2) Calculating subjective weight based on preference information of a decision maker, and solving the subjective weight based on ICRC; the classification stage and the reference comparison stage form a solving framework of the weight subjective experience decision.

2.1) index Classification

According to the primary classification index of expert experience, j evaluation indexes chi are set₁,χ₂,......,χ_jAccording to expert's experience, the index χ under the same criterion_kAnd classifying the data into four different importance levels: core level S₁Supporting level S₂Base level S₃Weakly associated hierarchy S₄：

S_i∈χ_k

According to the significance and the distribution characteristics of the importance degree of each level, the classification principle is defined as follows:

classification principle 1: corresponds to S₁、S₂、S₃、S₄The number ratio of the distribution indexes is as follows:

above formula b₁Representing that the core layer covers 20% of the index, b₂Representing an index covering 30% of the supporting layer, b₃Index representing 40% coverage of the base layer, b₄The number of layers representing weak association is 10% of the total index.

Principle of classification2: corresponds to S₁、S₂、S₃、S₄The weights of the four levels are:

the importance degree p of the core layer index is represented in the formula₁The weight of the criterion, θ, which can be expressed as 40%, the degree of importance of the support layer index, p₂The criterion weight, which can be expressed as 30%, the importance level p of the base layer index₃The weight of the criterion, which can be expressed as 20%, the degree of importance p of the weakly associated layer indicator₄This criterion weight can be expressed as 10%.

2.2) reference comparison

According to expert experience, respectively selecting one most important index from four levels as a reference index chi_{Reference to}The importance of the reference index can be used as a judgment criterion for determining the weight, namely, the rest indexes and the reference index are compared and scored pairwise, the index score values are summed according to lines to obtain the score sum of each index, and finally, the weighted average processing is carried out to obtain the subjective weight coefficient v of the index_k。

After grading, the standard index χ_{Reference to}Relative comparative score set as m_k，

m_k＝χ_k/χ_{Reference to}

Wherein the score m_kThe scoring criteria are as follows:

TABLE 1 RC method score table

Of importance	Of greater importance	Of less importance	Is less important than
				0.9	0.6	0.3	0.1

Obtaining an evaluation vector:

α_i＝[m₁...,m_k,...]^T

calculating the weight value theta after the grading is finished_iIs S_iThe sum of the assigned weights, p_iIs S_iAssigned weight percentage, define k 1, if S_i∈χ_kCorresponding score value m_k，ν_kSubjective weighting factor:

the obtained subjective weights are: v ═ V₁,ν₂...,ν_j]^T。

3) And calculating the objective weight based on the evaluation data, namely calculating the values of the index variance, the information entropy and the grey correlation degree, and obtaining the objective weight through weighted average.

(1) Calculating the index variance:

wherein μ represents a sample subscript, k represents an index subscript, e_μkValue representing the kth index of the μ th sample

(2) Calculating index information entropy:

(3) calculating the grey correlation degree of the index:

Δ_k(q)＝|X₀(q)-X_k(q)|

in the formula, k represents index subscript, X₀(q) is an index value of the reference number series, ξ_kThe term (q) denotes a correlation coefficient, and ρ denotes a resolution coefficient, and ρ is usually 0.5.

Comparing the degree of relatedness of a sequence to a reference sequence

Values are generally expressed as averages, i.e.:

(5) weighted average integration of objective weights:

the objective weights obtained were: f ═ F₁,f₂...,f_j]^T。

4) The subjective and objective weight combination based on the normalization formula comprises the following specific processes:

4.1) normalization formula calculates the combining weight:

obtaining a weight vector of W ═[w₁,w₂...,w_j]^T。

Example 2

The invention also provides a power grid engineering operation benefit evaluation system for optimizing the grid structure, which comprises the following components:

In a preferred embodiment, the specific evaluation process of the project performance evaluation module is as follows:

calculating contribution performance sigma of the change situation of the peripheral power grid connection structure, namely the grid structure before and after the project is put into operation, evaluating the importance of the project according to the sigma, and recording the evaluation result as D₁₁Optimizing the net rack according to the construction of the projectWhether the effect of the structure is significant on D₁₁Setting the value of (c);

R_ab＝C_a/C_b

In the formula, C_aFor line running of actual current, C_bFor line-card current, according to R_abThe importance of the process was evaluated and the evaluation result was recorded as D₁₂Whether the effect of the construction of the project on optimizing the grid structure is significant or not is judged for D₁₂Setting the value of (c);

in the formula, delta R is the difference between the average power supply radiuses of regional power grids before and after project operation, S is the power supply area of the region where the project is located, N is the total number of the substations of the regional power grids where the project is located before the project operation, project importance evaluation is carried out according to the delta R, and the evaluation result is marked as D₁₃Whether the effect of the construction of the project on optimizing the grid structure is significant or not is judged for D₁₃Setting the value of (c);

calculating D from the above results₁：D₁＝a₁₁D₁₁+a₁₂D₁₂+a₁₃D₁₃According to D₁Evaluating the effect of the engineering construction on enhancing the optimization capability of the grid structure, wherein a₁₁、a₁₂、a₁₃Respectively contributing performance for improving the grid structure, checking the weight of the ratio and the difference value of the average power supply radius in the performance evaluation, a₁₁+a₁₂+a₁₃1 according to D₁And evaluating the optimization capability of the construction of the project on strengthening the grid structure according to the comparison result with the preset value.

In a preferred embodiment, the specific evaluation process of the project effect evaluation module is as follows:

computingMaximum load factor mu of engineering transformer_max,t：μ_max,t＝P_max,t/S_tIn the formula, mu_max,tThe maximum load rate of the transformer is obtained; p_max,tFor the maximum load of the transformer, S_tEvaluating the engineering operation effect according to the interval of the maximum load rate after the transformer is put into operation for a preset time for the rated capacity of the transformer, and recording the evaluation result as D₂₁According to whether the engineering operation effect reaches the expected pair D₂₁Setting the value of (c);

Calculating the power factor at the moment of maximum load

calculating the power factor at the moment of minimum load

R_s＝∑S_ei/P_max

calculating D from the above index₂According to D₂And evaluating the engineering effect with the comparison result of the preset threshold: d₂＝a₂₁D₂₁+a₂₂D₂₂+a₂₃D₂₃+a₂₄D₂₄+a₂₅D₂₅+a₂₆D₂₆+a₂₇D₂₇+a₂₈D₂₈+a₂₉D₂₉Wherein a is₂₁、a₂₂、a₂₃、a₂₄、a₂₅、a₂₆、a₂₇、a₂₈、a₂₉Respectively the weights of the maximum load rate of the engineering transformer, the average load rate of the engineering transformer, the maximum load rate of the engineering line, the average load rate of the engineering line, the loss of the overhead line, the main transformer loss, the power factor at the maximum load moment, the power factor at the minimum load moment and the capacity-to-load ratio in the efficiency evaluation, a₂₁+a₂₂+a₂₃+a₂₄+a₂₅+a₂₆+a₂₇+a₂₈+a₂₉＝1。

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks. The above embodiments are only used for illustrating the present invention, and the implementation steps of the method and the like can be changed, and all equivalent changes and modifications based on the technical scheme of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. a power grid engineering operation benefit evaluation method of optimizing grid structure is characterized in that comprising the following content:

Collect actual operating power data that needs to be evaluated;

According to the collected power data, the performance of the power grid engineering project with the optimized grid structure is evaluated. The project efficiency evaluation indicators include the contribution performance of improving the grid structure, the check ratio of the bayonet current and the average power supply radius difference. The specific evaluation process is as follows:

Calculate the change of the wiring structure of the surrounding power grid before and after the project is put into operation, that is, the contribution performance σ of the grid structure, and evaluate the importance of the project according to σ, and the evaluation result is recorded as D ₁₁ . ₁₁ to set the value;

Calculate the ratio _Rab of the actual current of the line operation to the current of the line bayonet:

_Rab = _Ca / _Cb

In the formula, C _a is the actual current of the line operation, C _b is the line bayonet current, according to the importance of _Rab to evaluate the project, the evaluation result is recorded as D ₁₂ , according to whether the construction of the project has a significant effect on optimizing the grid structure. The value of D ₁₂ is set;

Calculate the difference ΔR between the average value of the geometric center and the boundary of the power supply range of the substation before and after the project is put into operation:

In the formula, ΔR is the difference between the average power supply radius of the regional power grid before and after the project is put into operation, S is the power supply area of the region where the project is located, and N is the total number of substations in the region where the project is located before the project is put into operation. It is recorded as D ₁₃ , and the value of D ₁₃ is set according to whether the construction of the project has a significant effect on optimizing the grid structure;

Calculate D ₁ according to the above results: D ₁ =a ₁₁ D ₁₁ +a ₁₂ D ₁₂ +a ₁₃ D ₁₃ , and evaluate the effect of the project construction on strengthening the optimization capability of the grid structure according to D ₁ , where a ₁₁ , a ₁₂ , a ₁₃ is the weight of the contribution performance of improving the grid structure, the check ratio of the bayonet current and the average power supply radius difference in the performance evaluation, a ₁₁ +a ₁₂ +a ₁₃ =1, according to the comparison between D ₁ and the preset value The results evaluate the construction of this project to strengthen the optimization ability of the grid structure;

According to the collected power data, the power grid engineering project effect of the optimized grid structure is evaluated. The project effect evaluation indicators include the maximum load rate of engineering transformers, the average load rate of engineering transformers, the maximum load rate of engineering lines, the average load rate of engineering lines, and the overhead lines. Loss, main transformer loss, power factor at the time of maximum load, power factor at the time of minimum load and load capacity ratio, the specific evaluation process is as follows:

Calculate the maximum load rate μ _max,t of the engineering transformer: μ _max,t =P _max,t /S _t , where μ _max,t is the maximum load rate of the transformer; P _max,t is the maximum load of the transformer, S _t It is the rated capacity of the transformer. After the transformer is put into operation for a preset time, the project operation effect is evaluated according to the interval of the maximum load rate. The evaluation result is recorded as D ₂₁ , and the value of D ₂₁ is set according to whether the project operation effect reaches the expectation;

Calculate the average load rate μ _avg,t of the engineering transformer: μ _avg,t =P _avg,t /S _t , where μ _avg,t is the average load rate of the transformer; P _avg,t is the annual average load of the transformer, S _t It is the rated capacity of the transformer and the time limit for the transformer to be put into operation. The project operation effect is evaluated according to the interval of the average load rate of the transformer. The evaluation result is recorded as D ₂₂ , and the value of D ₂₂ is set according to whether the project operation effect reaches the expectation;

Calculate the maximum load rate of the line μ _max,1 : μ _max,1 =P _max,1 /S ₁ , where μ _max,1 is the maximum load rate of the line; P _max,l is the maximum load that occurs on the line, and S _l is The rated capacity of the line, after the line has been put into operation for a set period of time, evaluate the project operation effect according to the interval of the maximum load rate of the line, and the evaluation result is recorded as D ₂₃ , and the value of D ₂₃ is set according to whether the project operation effect reaches the expectation;

Calculate the line average load rate μ _avg,1 : μ _avg,1 =P _avg,1 /S ₁ , where μ _avg,1 is the line average load rate; P _avg,l is the line annual average load; S _l is the line Rated capacity line; after the set period of operation, the project operation effect is evaluated according to the percentage interval of the average load rate of the line, and the evaluation result is recorded as D ₂₄ , and the value of D ₂₄ is set according to whether the project operation effect reaches the expectation;

Calculate overhead line loss Q _l,l : Q _ll =Q _in -Q _out , in the formula, Q _in is the input power of the transformer, Q _out is the output power of the transformer, and the project operation effect is evaluated according to the overhead line loss, and the evaluation result is recorded as D ₂₅ , set the value of D ₂₅ according to whether the project operation effect reaches the expectation;

Calculate the main transformer loss Q _l,t , Q _lt =Q _in -Q _out , where Q _in is the transformer input power, unit MWh; Q _out is the transformer output power, according to the main transformer loss to evaluate the project operation effect, the evaluation results Denoted as D ₂₆ ;

Calculate the power factor at the time of maximum load

In the formula, S is the apparent power delivered by the equipment at the time of maximum load, P is the active power delivered by the equipment at the time of maximum load, Q is the reactive power delivered by the equipment at the time of maximum load, and the project operation effect is evaluated according to the power factor at the time of maximum load, The evaluation result is recorded as D ₂₇ , and the value of D ₂₇ is set according to whether the project operation effect reaches the expectation;

Calculate the power factor at the minimum load moment

In the formula, S is the apparent power delivered by the equipment at the minimum load time, P is the active power delivered by the equipment at the minimum load time, Q is the reactive power delivered by the equipment at the minimum load time, and the project operation effect is evaluated according to the power factor at the minimum load time, The evaluation result is recorded as D ₂₈ , and the value of D ₂₈ is set according to whether the project operation effect reaches the expectation;

Calculate the ratio Rs of the total capacity of the public substation equipment to the corresponding total load in a power supply area of the grid and the grid of the same voltage level after the project is put into operation:

R _s =∑S _ei /P _max

In the formula, ∑S _ei is the maximum load on the maximum load day of the voltage level; P _max is the total capacity of the substations that are put into operation on the maximum load day of the voltage level. Project operation effect evaluation, the evaluation result is recorded as D ₂₉ , and the value of D ₂₉ is set according to whether the project operation effect reaches the expectation;

Calculate D ₂ according to the above indicators, and evaluate the engineering effect according to the comparison result of D ₂ and the preset threshold: D ₂ =a ₂₁ D ₂₁ +a ₂₂ D ₂₂ +a ₂₃ D ₂₃ +a ₂₄ D ₂₄ +a ₂₅ D ₂₅ + a ₂₆ D ₂₆ +a ₂₇ D ₂₇ +a ₂₈ D ₂₈ +a ₂₉ D ₂₉ , wherein a ₂₁ , a ₂₂ , a ₂₃ , a ₂₄ , a ₂₅ , a ₂₆ , a ₂₇ , a ₂₈ , and a ₂₉ are respectively The maximum load rate of engineering transformers, the average load rate of engineering transformers, the maximum load rate of engineering lines, the average load rate of engineering lines, overhead line losses, main transformer losses, power factor at the time of maximum load, power factor at the time of minimum load, and capacity-load ratio are used in performance evaluation The weight in , a ₂₁ +a ₂₂ +a ₂₃ +a ₂₄ +a ₂₅ +a ₂₆ +a ₂₇ +a ₂₈ +a ₂₉ =1;

According to the collected power data, the project safety of the optimized grid structure project is evaluated. The evaluation indicators of the project safety include main transformer availability, line availability, bus voltage qualification rate, number of power grid safety accidents, relay protection and stabilization devices. The number of malfunctions and refusals, the unplanned outage time of the transformer, the number of unplanned outage hours of the line, the frequency of the unplanned outage of the line and the line trip rate. The specific evaluation process is as follows:

Calculate the main transformer availability A _T :

In the formula: μ is the forced outage rate, T _r is the average fault repair time, T _ΣA is the cumulative fault-free working time of the equipment, T _Σ is the cumulative operation time, and the project safety and reliability are evaluated according to the availability of the main transformer. The result is represented by D ₃₁ , and the D ₃₁ value is determined according to the degree of engineering safety and reliability;

Calculate the line availability _AL :

In the formula, u is the forced outage rate, T _r is the average fault repair time, T _ΣA is the cumulative fault-free working time of the equipment, T _Σ is the cumulative commissioning time, and the engineering safety and reliability are evaluated according to the line availability. It is represented by D ₃₁ , and the D ₃₂ value is determined according to the degree of engineering safety and reliability;

Calculate the project busbar phase A voltage pass rate η _A : η _A %＝(1-T _b /T _Σ )*100%, in the formula, η _A is the project bus bar phase A voltage pass rate, T _b is the accumulated time of voltage violation , T _Σ is the total operation statistical time of the project, the project safety and reliability is evaluated according to the pass rate of the bus A-phase voltage, the evaluation result is recorded as D ₃₃ , and the D ₃₃ value is determined according to the project safety and reliability degree;

Count the number of power grid safety accidents _Ja , and evaluate the project safety and reliability according to the number of power grid safety accidents. The evaluation result is recorded as D ₃₄ , and the D ₃₄ value is determined according to the degree of project safety and reliability;

Calculate the number of malfunctions and _refusals of the relay protection and stabilization devices inside the project or the stabilization devices in other positions in the power grid caused by the project operation. The reliability is evaluated, and the evaluation result is recorded as D ₃₅ , and the D ₃₅ value is determined according to the degree of engineering safety and reliability;

Calculate the unplanned outage time ∑T _dt of the transformer, and evaluate the safety and reliability of the project according to the unplanned outage hours of the transformer. The evaluation result is recorded as D ₃₆ , and the D ₃₆ value is determined according to the degree of project safety and reliability;

Obtain the number of unplanned outage hours ∑T _dl of the line, and evaluate the safety and reliability of the project according to the number of unplanned outage hours of the line. The evaluation result is recorded as D ₃₇ , and the value of D ₃₇ is determined according to the degree of project safety and reliability;

Count the unplanned outage frequency f _l of the line, and evaluate the safety and reliability of the project according to the frequency of unplanned outage of the line. The evaluation result is recorded as D ₃₈ , and the D ₃₈ value is determined according to the degree of project safety and reliability;

Calculate the trip rate caused by the external environment or insulation problems of the line operation: λ=M/T, where λ is the non-intrinsic trip rate of the line, and M is the total trip rate during the statistical period, not due to the capacity of the line itself or insulation problems. The number of times, T is the evaluation time, the safety and reliability of the project is evaluated according to the line trip rate, and the evaluation result is recorded as D ₃₉ , and the value of D ₃₉ is determined according to the degree of project safety and reliability;

Carry out engineering safety evaluation according to the above indicators, and the evaluation result is represented by D ₃ : D ₃ =a ₃₁ D ₃₁ +a ₃₂ D ₃₂ +a ₃₃ D ₃₃ +a ₃₄ D ₃₄ +a ₃₅ D ₃₅ +a ₃₆ D ₃₆ +a ₃₇ D ₃₇ +a ₃₈ D ₃₈ +a ₃₉ D ₃₉ , among which, a ₃₁ , a ₃₂ , a ₃₃ , a ₃₄ , a ₃₅ , a ₃₆ , a ₃₇ , a ₃₈ , a ₃₉ are respectively the availability of the main transformer and the availability of the line degree, bus voltage qualification rate, number of grid safety accidents, number of malfunctions and refusals of relay protection and stabilization devices, unplanned outage time of transformers, hours of unplanned outages of lines, frequency of unplanned outages of lines and line trips The weight of 9 indicators in the safety evaluation, and a ₃₁ +a ₃₂ +a ₃₃ +a ₃₄ +a ₃₅ +a ₃₆ +a ₃₇ +a ₃₈ +a ₃₉ =1; according to the comparison of D ₃ with the preset value The results evaluate whether the safety and reliability of the project is qualified;

Comprehensively consider the project efficiency, project effect and project safety, and comprehensively evaluate the operation effect of the optimized grid structure project. The specific process of evaluation is as follows:

1) Calculate the comprehensive evaluation value of the operation effect. The calculation formula of the comprehensive evaluation of the operation effect is:

D=a ₁ D ₁ +a ₂ D ₂ +a ₃ D ₃

Among them, a ₁ , a ₂ , and a ₃ are the weights of project effectiveness D ₁ , project effect D ₂ , and project safety D ₃ respectively, a ₁ +a ₂ +a ₃ =1;

2) When D < the set minimum threshold, it is considered that the project has a poor operation effect as an optimized grid structure project;

When the set minimum threshold ≤ D < the set maximum threshold, it is considered that the optimized grid structure of the project has a good operation effect;

When D ≥ the set maximum threshold, it is considered that the project has a good performance in optimizing the grid structure.

2. The power grid engineering operation benefit evaluation method for optimizing the grid structure according to claim 1, wherein the a ₁ , a ₂ , and a ₃ adopt a weight solving algorithm combining an index classification reference comparison method and a combination of subjective and objective weights Solve to get.

3. The power grid engineering operation benefit evaluation method of optimizing grid structure as claimed in claim 1, is characterized in that, before calculating the comprehensive evaluation value D of operation effect, further comprises:

Determine the comment level domain of D ₁ , D ₂ , D ₃ ;

According to the evaluation of efficacy D ₁ , the comment level domain is determined as d ₁ ={d ₁₁ , d ₁₂ , d ₁₃ }, wherein d ₁₁ represents important, d ₁₂ represents general importance, and d ₁₃ represents unimportant;

For the evaluation of the effect D ₂ , the universe of discourse is determined as d ₂ ={d ₂₁ ,d ₂₂ }, where d ₂₁ represents satisfying the requirement, and d ₂₂ represents not satisfying the requirement;

For the safety _D3 evaluation, the universe of discourse is determined as d ₃ ={d ₃₁ ,d ₃₂ }, where d ₃₁ represents qualified, and d ₃₂ represents unqualified;

Convert the above qualitative evaluations to numerical values.

4. A power grid engineering operation benefit evaluation system for optimizing grid structure, is characterized in that, this system comprises:

A data acquisition module for collecting actual operating power data that needs to be evaluated;

The project efficiency evaluation module is used to evaluate the efficiency of the power grid engineering project with the optimized grid structure according to the collected power data. The project efficiency evaluation indicators include the contribution performance of improving the grid structure, the check ratio of the bayonet current and the average power supply radius difference. ; Among them, the specific evaluation process of the project effectiveness evaluation module is as follows:

_Rab = _Ca / _Cb

The project effect evaluation module is used to evaluate the effect of the power grid engineering project of the optimized grid structure according to the collected power data. The project effect evaluation indicators include the maximum load rate of engineering transformers, the average load rate of engineering transformers, the maximum load rate of engineering lines, and the Line average load rate, overhead line loss, main transformer loss, power factor at the time of maximum load, power factor at the time of minimum load, and load capacity ratio. The specific evaluation process of the project effect evaluation module is as follows:

Calculate the power factor at the time of maximum load

Calculate the power factor at the minimum load moment

R _s =∑S _ei /P _max

Calculate D ₂ according to the above indicators, and perform engineering effect evaluation according to the comparison result of D ₂ and the preset threshold: D ₂ =a ₂₁ D ₂₁ +a ₂₂ D ₂₂ +a ₂₃ D ₂₃ +a ₂₄ D ₂₄ +a ₂₅ D ₂₅ + a ₂₆ D ₂₆ +a ₂₇ D ₂₇ +a ₂₈ D ₂₈ +a ₂₉ D ₂₉ , wherein a ₂₁ , a ₂₂ , a ₂₃ , a ₂₄ , a ₂₅ , a ₂₆ , a ₂₇ , a ₂₈ , and a ₂₉ are respectively The maximum load rate of engineering transformers, the average load rate of engineering transformers, the maximum load rate of engineering lines, the average load rate of engineering lines, overhead line losses, main transformer losses, power factor at the time of maximum load, power factor at the time of minimum load, and capacity-load ratio are used in performance evaluation The weight in , a ₂₁ +a ₂₂ +a ₂₃ +a ₂₄ +a ₂₅ +a ₂₆ +a ₂₇ +a ₂₈ +a ₂₉ =1;

The project safety evaluation module is used to evaluate the project safety of the optimized grid structure project according to the collected power data. The evaluation indicators of the project safety include main transformer availability, line availability, bus voltage qualification rate, and the number of power grid safety accidents. , The number of malfunctions and refusals of relay protection and stabilizing devices, the unplanned outage time of the transformer, the number of unplanned outage hours of the line, the frequency of unplanned outage of the line and the line trip rate;

It is a comprehensive evaluation module used to comprehensively evaluate the operation effect of the optimized grid structure project considering the project efficiency, project effect and project safety.