CN112541618B

CN112541618B - Active power distribution network planning method based on gridding and storage medium

Info

Publication number: CN112541618B
Application number: CN202011370156.0A
Authority: CN
Inventors: 贺春光; 檀晓林; 安佳坤; 邵华; 张菁; 臧志斌; 赵建伟; 赵光; 李向荣; 吴献立; 黄凯; 胡诗尧; 翟广心; 赵子珩; 杨书强; 孙鹏飞; 郭伟; 韩璟琳; 范文奕
Original assignee: XIAMEN GREAT POWER GEO INFORMATION TECHNOLOGY CO LTD; State Grid Corp of China SGCC; State Grid Information and Telecommunication Co Ltd; Economic and Technological Research Institute of State Grid Hebei Electric Power Co Ltd
Current assignee: XIAMEN GREAT POWER GEO INFORMATION TECHNOLOGY CO LTD; State Grid Corp of China SGCC; State Grid Information and Telecommunication Co Ltd; Economic and Technological Research Institute of State Grid Hebei Electric Power Co Ltd
Priority date: 2020-11-30
Filing date: 2020-11-30
Publication date: 2023-01-10
Anticipated expiration: 2040-11-30
Also published as: CN112541618A

Abstract

The invention discloses an active power distribution network planning method and a storage medium based on meshing, wherein the method comprises the following steps: sequentially dividing a preset planning area into a unit plot, a power supply unit and a power supply grid from small to large; carrying out load prediction on the planning area to obtain a load prediction result; according to the load prediction result, carrying out constant volume and site selection on the transformer substation; and carrying out power grid analysis and power grid evaluation on the planning area. The method can provide data support and scientific basis for power grid planning decision-making, realize accurate planning, assist relevant technicians to make decisions, and achieve the purpose of improving the working efficiency.

Description

Active power distribution network planning method based on gridding and storage medium

Technical Field

The invention relates to the technical field of active power distribution networks, in particular to an active power distribution network planning method based on meshing and a storage medium.

Background

At present, a grid development specialty does not apply geographic information technology to design a related grid structure model, and grid models designed by other business departments are not completely suitable for the development specialty. In order to get through barriers such as inconsistent data standards and insufficient sharing of various service departments, it is one of key points and difficulties how to meet the requirements of power distribution network planning on hierarchical display of a grid frame and related index display analysis by designing a related power grid model.

The power grid geographic information resource is often just used as a background signboard and is not associated with the power grid resource at all. In the power grid analysis, how to fuse two-source related information according to the characteristics of geographic resources and power grid resources, and realizing the new mode of the two-source integrated analysis and display of the graph network is one of key points and difficulties.

In addition, conventional electrical calculation models and methods generally do not take into account the effects of increasing numbers of distributed power sources, such as wind power generation and solar photovoltaic power generation, in a regional power grid. The comprehensive consideration of the factors ensures the scientificity and rationality of electrical calculation, which is one of key points and difficulties.

The development level of the built power distribution network, such as key indexes of power supply reliability, voltage quality, frequency quality, fault recovery time and the like, can support economic and social development, can match with the requirements of a novel urbanization process and can meet the requirements of an energy consumption revolution on a power grid, and is an important judgment standard for judging whether a planning scheme is effective and reasonable. Meanwhile, the matching degree of the planning scheme target setting and the investment scheme is also an important aspect for measuring whether the planning scheme is accurate, economic and efficient. Therefore, how to select key indexes and evaluation models and evaluate whether the town power distribution network adopting the new technical standard and the new technology meets the requirements of different town industries and social development or not is economic and efficient, and is one of key points and difficulties.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the active power distribution network planning method and the storage medium based on gridding are provided, accurate planning can be achieved, and working efficiency is improved.

In order to solve the technical problems, the invention adopts the technical scheme that: an active power distribution network planning method based on gridding comprises the following steps:

sequentially dividing a preset planning area into a unit land block, a power supply unit and a power supply grid from small to large;

carrying out load prediction on the planning area to obtain a load prediction result;

according to the load prediction result, carrying out constant volume and site selection on the transformer substation;

and carrying out power grid analysis and power grid evaluation on the planning area.

The invention also proposes a computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method as described above.

The invention has the beneficial effects that: the space load prediction of the active power distribution network can be realized, the positions and the capacities of the transformer substations to be built in the target year and the middle year can be determined according to the space load prediction result, the multi-dimensional statistical analysis, the topological analysis and the wiring analysis of the power distribution network are realized, and further electric calculation analysis is completed. Based on the data comprehensive analysis, scientific basis and effective support are provided for the efficient investment of the accurate planning of the power distribution network. The method can provide data support and scientific basis for power grid planning decision-making, realize accurate planning, assist relevant technicians to make decisions, and achieve the purpose of improving the working efficiency.

Drawings

Fig. 1 is a flowchart of an active power distribution network planning method based on meshing according to a first embodiment of the present invention;

fig. 2 is a schematic diagram of a substation site selection of a planning area of an existing substation according to a second embodiment of the present invention;

fig. 3 is a schematic diagram of site selection of a substation in a planning area where no substation exists yet according to the second embodiment of the present invention.

Detailed Description

In order to explain technical contents, objects and effects of the present invention in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.

Example one

Referring to fig. 1, a first embodiment of the present invention is: an active power distribution network planning method based on gridding can be applied to active power distribution network planning and comprises the following steps:

s1: sequentially dividing a preset planning area into a unit land block, a power supply unit and a power supply grid from small to large;

specifically, according to a region corresponding to a county administrative district, a planning region is determined, that is, the administrative district is divided by taking a county (district) as a unit to obtain the planning region; gridding and dividing the planning area to obtain more than one power supply grid; dividing each power supply grid respectively to obtain more than one power supply unit; and respectively dividing each power supply unit to obtain more than one unit plot.

S2: and carrying out load prediction on the planning area to obtain a load prediction result. The load prediction comprises a long-range load prediction and a near-intermediate load prediction.

The long-range load prediction specifically comprises the following steps:

s211: and collecting functional land index information in each unit block respectively, wherein the functional land index information comprises large user information, distributed power supply information and multi-load information.

Wherein, the big user information comprises: large user name, voltage class, reinstatement capacity, commissioning time, and historical annual maximum load; the distributed power supply information includes: power name, voltage class, power class, capacity, and commissioning time; multivariate load information: multiple load type, name, voltage class, storage capacity, peak power (capacity = peak power time), and commissioning time.

S212: and respectively calculating the saturation annual load of each unit plot according to the functional land index information.

Specifically, if a corresponding land planning map exists in a unit plot, calculating the saturation annual load of the unit plot by a space load prediction method; if a unit plot does not have a corresponding land planning map and the category of the unit plot is a special land or water area or other land, calculating the saturated annual load of the unit plot according to the number of users in the unit plot and a preset single-user-number perspective average highest load typical value; and if the unit plot does not have the corresponding land planning map and belongs to a mature development area, calculating the saturation annual load of the unit plot by using an average growth rate method.

S213: and determining the saturated load value of the unit plot according to the maximum value of the historical annual maximum load and the saturated annual load in the large user information of the unit plot.

S214: and calculating a long-range load predicted value of the power supply grid according to the saturated load value and the preset concurrence rate of each unit land parcel in the power supply grid. Preferably, the default value of the coincidence rate is 0.8, which can be modified according to the category of the unit block.

Furthermore, the predicted value of the long-range load of a power supply unit can be calculated according to the saturated load value and the preset coincidence rate of each unit block in the power supply unit.

S215: and calculating the long-term annual load of the planning area according to the long-term load predicted value of each power supply grid.

The near-middle-period load prediction specifically comprises the following steps:

s221: collecting power grid basic data of a current year and a plurality of historical years of a power grid, wherein the power grid basic data comprise distribution transformer of each unit plot, maximum load information of a circuit and corresponding time of the maximum load information, and load data of a circuit outlet switch 8760 point; further, the system also comprises population, GDP, industrial electricity consumption (comprising agriculture, forestry, animal husbandry and fishery industry, transportation, storage and postal industry, information transmission, software and information technology service industry, wholesale and retail industry, lodging and catering industry, financial industry, housing and land industry, leasing and business service industry, public service and management organization and the like), industrial electricity consumption (comprising first industry, second industry, third industry, urban and rural resident electricity consumption) and the like.

S222: and calculating the total regional social load of the current year according to the power grid basic data of the current year.

S223: and calculating the current year load of the power supply grid according to the total regional and social load of the current year, the proportion of the total load of the power supply grid in a saturation year to the total regional and social load of the current year or the proportion of the distribution and transformation capacity of the power supply grid in the current year to the total distribution and transformation capacity of the power supply grid in the current year.

The step provides two algorithms, namely a 'top-down' proportion allocation algorithm based on saturation years and a 'top-down' proportion allocation method based on distribution capacity.

The calculation formula of the proportion allocation algorithm based on the saturation year from top to bottom is as follows: grid existing load = total load of the whole community of the area × proportion of total load of the area occupied by the grid in saturated years.

The calculation formula based on the distribution transformation capacity 'top-down' proportion apportionment method is as follows: the grid existing load = total load of the whole area society x the proportion of the grid present distribution capacity to the total distribution capacity of the area.

S224: and calculating the current annual load of the power supply area according to the current annual load of each power supply grid. The current annual load of each power supply grid is accumulated to obtain the current annual load of the power supply area.

S225: respectively calculating the total regional social load of each historical year according to the basic data of the power grid of each historical year;

s226: and calculating the planned target year load of the planned region by a near-middle period load prediction method according to the total regional social load of the current year and each historical year, wherein the near-middle period load prediction method comprises an annual average growth rate method, a binary regression method, a ternary regression method, an exponential growth method, an S curve model and a large user method, and further comprises a yield value unit consumption, an elastic coefficient, an industrial power utilization method, a maximum load utilization hour number method and the like.

The method for calculating the regional total social load in steps S222 and S225 includes a "bottom-up" cumulative method based on line load and a "bottom-up" cumulative method based on distribution.

Based on the cumulative method of line loads from bottom to top, specifically, the data of all 10 kilovolt lines 8760 of the power supply grid are superposed and then the maximum value is obtained, the data of direct supply loads of 35kV or more and distributed power supplies are superposed, and the calculation formula is as follows: the regional whole social load = regional 10kV network supply line load +10kV special line load +35kV and above direct supply load +10kV grid-connected power output + low-voltage grid-connected power output + spontaneous self-service power. The power supply amount of the network (of the equipment, the line, the power supply unit and the grid) is directly accumulated, and the download power and the upload power are respectively calculated and stored.

Further, if there are lines across the power grids, the power grid to which the line has a large occupation ratio belongs.

The 'bottom-up' accumulation method based on the distribution transformation specifically comprises the following steps: adding the data of the distribution transformer 8760 points of the power supply grid, then taking the maximum value, and storing the data of the 8760 points; data of large users and distributed power supplies with power of 35kV or more are required to be superposed. The power supply amount of the network (of the equipment, the line, the power supply unit and the grid) is directly accumulated, and the download power and the upload power are respectively calculated and stored.

S3: and performing constant volume and site selection of the transformer substation according to the load prediction result.

Firstly, the constant volume of a transformer substation is performed, and the method specifically comprises the following steps:

s311: and setting a value range of the capacity-load ratio according to the preset load acceleration of the planning area. For example, if the load acceleration Kp is less than or equal to 7%, the value range of the capacity-load ratio is 1.8-2.0; if Kp is more than 7% and less than or equal to 12%, the value range of the capacity-load ratio is 1.9-2.1; if Kp is more than 12%, the value range of the capacity-carrying ratio is 2.0-2.2.

S312: and calculating a newly increased capacity range according to the planned target annual load, the capacity-to-load ratio value range and the existing capacity data of the planned area.

Specifically, added capacity = planned target annual load capacity-to-existing capacity.

S313: setting a constant volume strategy, wherein the constant volume strategy is point placement firstly or expansion firstly. Newly increased stationing is mainly used for a fast-growth region and a mature saturation region (stationing is difficult or income is fast); and for the area with the load slowly increasing in the initial stage and the investment benefit difficult to recover for a long time, the expansion of the main transformer is taken as the main part under the condition of meeting the requirement.

S314: and determining the number and the capacity of the transformer substations according to the constant volume strategy, the voltage grade and the type of the power supply area.

Then site selection of the transformer substation is carried out, specifically, for a planning area of the existing transformer substation, the maximum power supply range of the existing transformer substation in the planning area is determined, then the area of the maximum power supply range and the area of a preset transformer substation which cannot be built are removed from the planning area, and the site selection range of the transformer substation is determined; and taking the geometric center point of the addressing range as a feasible point distribution area.

For a planning area in which a transformer substation is not built, calculating the current load density of each power supply grid according to the current annual load and area of each power supply grid in the planning area; carrying out topology identification on the power supply grid with the current load density higher than a preset value to obtain a first central point; carrying out topology identification on all power supply grids in the planned area to obtain a second central point; taking the midpoint of the connecting line of the first central point and the second central point as a feasible point distribution area;

and finally, determining the address of the newly-built substation according to the feasible stationing area and the perspective annual load of the planning area.

S4: and carrying out power grid analysis and power grid evaluation on the planning area.

Specifically, grid statistics, grid topology analysis, wiring mode analysis and auxiliary electrical calculation are performed on a power grid with a voltage class of 35kV or more in the planned area.

The power grid statistics is to count the type, year, planning property and the like of the power grid equipment, and relevant information is checked according to a statistical result. For example: for lines, the statistics include line name, time of day, type (overhead, cable), starting station, terminating station, etc.

The power grid topology analysis is to analyze the net rack of 35kV or above, find out the topological connection relation and the electrified range of the net rack, prepare data for typical wiring mode identification and give out detailed analysis results.

And the wiring mode analysis is to identify the wiring mode of the net rack of 35kV or above, find out typical wiring modes such as radiation, chain type, ring type, T connection, pi connection and the like, and give out a detailed analysis result.

The auxiliary electrical calculations include, but are not limited to, the following electrical calculations: (1) carrying out load flow calculation; (2) short circuit calculation; and (3) calculating the N-1 passing rate.

Furthermore, power grid statistics, power grid topology analysis, wiring mode analysis, auxiliary electrical calculation and power grid evaluation are carried out on the power grid with the voltage class of 10kV or below in the planning area.

Wherein, the power grid statistics are as above.

The power grid topology analysis is to analyze the 10kV net rack and the net rack, find out the topological connection relation and the electrified range of the net rack, prepare data for typical wiring mode identification, trunk analysis, longest path analysis, topological island analysis and segmented contact analysis, and give out detailed analysis results.

And the wiring mode analysis is to identify the wiring mode of the 10kV net rack, find out the typical wiring modes of the overhead net, the cable net and the mixed net rack and give out a detailed analysis result.

The auxiliary electrical calculations include, but are not limited to, the following electrical calculations: (1) short circuit calculation; and (2) calculating the N-1 passing rate.

The indexes of the power grid evaluation comprise comprehensive indexes, power grid structure indexes, equipment level indexes, power supply capacity indexes, intelligent and green development indexes and power grid benefit indexes.

Wherein the comprehensive indexes comprise the average power failure time of a user, the comprehensive voltage qualification rate and the comprehensive line loss rate of 10kV or below. The power grid structure indexes comprise the average power supply radius of a 10kV line, the average number of sections of the 10kV overhead line, the contact rate of the 10kV line, the contact rate between 10kV line stations, the N-1 passing rate of the 10kV line and the standard wiring proportion of the 10kV line. The equipment level indexes comprise the average operation age of 10kV in-operation equipment, the cabling rate of a 10kV line, the insulation rate of a 10kV overhead line and the proportion of a 10kV high-loss distribution transformer. The power supply capacity indexes comprise the average value of the maximum load rate of the 10kV line, the occupation ratio of the 10kV heavy-load line, the average value of the maximum load rate of the 10kV distribution transformer, the occupation ratio of the 10kV heavy-load distribution transformer, the installation capacity of the 10kV line and the unsafe load of the 10kV line. The intelligent and green development indexes comprise distribution automation coverage rate, three-remote terminal occupation rate, distribution transformer information acquisition rate, distributed power supply permeability and distributed power supply absorption rate. The power grid benefit indexes comprise unit investment increase and supply load and unit investment increase and sale electric quantity.

According to the embodiment, the space load prediction of the active power distribution network can be realized, the positions and the capacities of the transformer substations to be built in the target year and the middle year can be determined according to the space load prediction result, the multi-dimensional statistical analysis, the topological analysis and the wiring analysis of the power distribution network are realized, and further electric calculation analysis is completed. Based on the data comprehensive analysis, scientific basis and effective support are provided for the efficient investment of the accurate planning of the power distribution network.

Example two

The present embodiment is a specific implementation scenario of the foregoing embodiments.

1. Gridding planning business process

Aiming at the characteristics of an online operation mode, a hierarchical collaborative planning operation mode is established according to the effective combination of problem guidance and target guidance, three layers of management of planning versions, planning schemes and planning projects are set, the merging of the planning versions in various areas, the comparison and selection of different planning schemes and the unified management of the planning projects are realized, the planning linkage of various hierarchies can be effectively strengthened, and the integrity, the continuity and the economy of grid planning are improved. The primary carding of the business process is as follows:

1. reference map setting

The planning reference time is determined, generally, 12 months and 31 days per year are taken as a time section, or a power grid section at the bottom of the previous month for starting a planning task is taken as a reference graph (the closer to the current time, the more practical the topological relation of the grid is), and the determined authority can be determined by superior units (state grids, provinces and city companies).

2. Planning area version management

The method comprises the steps of establishing a planning area version by taking a county (district) as a unit, and dividing and drawing a power supply area, a power supply grid, a power supply unit and a rural and urban network on a reference diagram by a governed unit. And after the drawing is finished, the planning region version can be modified according to the actual situation, and the new version can be modified on the basis of the released version.

3. Planning version creation

After the setting of the reference diagram and the release of the planning regional versions are completed, for normal planning work, a county (district) company autonomously creates a planning version of a next stage, sub-versions can be created according to actual requirements, all sub-versions can be mutually overlapped and released according to a finally confirmed sub-version, and the released sub-versions have a merging function. The upper level unit mainly issues planning tasks in a unified manner.

4. Power grid diagnostics

By means of the diagnosis model, typical day data such as the maximum load day of the year of the planning reference time is taken as a basis, the problem base list collected in the time period is combined, diagnosis and analysis are conducted on the power grid, the problem lists such as scheduling and operation and inspection are comprehensively considered, and after manual secondary verification and confirmation, the problem lists are converged and circulated to the problem base.

5. Load prediction

The method mainly adopts space load prediction to measure and calculate the power supply grid saturated load and each planned horizontal year load from bottom to top step by step, checks the power supply grid division according to the prediction result of the saturated load, needs to adjust the power supply grid (unit), and modifies the version of a planned area.

6. Planning objective

And importing or manually drawing a target net rack, setting a planning target index value and providing a comparison standard for subsequent net rack planning and effect analysis.

7. Planning plan creation

The method comprises the steps of screening out problem lists existing in grid areas by taking a single or multiple grids as a unit, associating the problem lists by combining load prediction requirements, considering a planning scheme, solving multiple problem conditions at the same time, focusing on connection with a target grid frame, and establishing the planning scheme aiming at different solutions, wherein the same planning scheme can be composed of one or a plurality of projects.

8. Comparison of economic technical schemes

Different schemes for solving the problems are compared and selected by methods such as an economic and technical method, load flow calculation, manual intervention and the like, and the schemes which are not required to be compared and selected are directly solidified after being audited.

9. Planning plan solidification

And determining a better planning scheme according to the selection result, solidifying the planning scheme, and automatically confirming and transferring the projects in the planning scheme to a planning project library for management.

10. Planning version release

After all the planning schemes of the edition are solidified, the solidified planning schemes are merged to form a stage planning edition result, the edition is released by taking county (district) companies as units, and all sub-editions can be merged.

11. Planning result

And forming a net rack planning geographical wiring diagram of the grid which is refined to 3 years before planning by taking county (district) as a unit, and counting the scale of the power grid equipment and the investment scale in the planning period and the year-by-year refined construction time sequence 3 years before the planning period.

2. Mesh partitioning

Plan area version management

The creation of the edition of the planning area is carried out by taking a county (district) as a unit, and the division and drawing of the power supply area, the power supply grid and the rural and urban network are carried out on a reference diagram by the governed unit. And after the drawing is finished, the layout area version can be modified according to the actual situation, and the new version can be modified on the basis of the released version.

1. Planning region version creation

The method comprises the steps of establishing a planning region version for a prefecture region by taking a county (region) as a unit, wherein the information comprises a planning version name, a region where the version is located, establishment time, an establishing person and the like.

2. Planning region versioning rendering

The planning region version content comprises drawing of a power supply region, a power supply grid, a power supply unit and a city rural power grid region, and setting three drawing modules of the city rural power grid, the power supply region, the power supply grid and the like.

3. Planning region version publishing

And after the planning area version is drawn, confirming and releasing after the verification is finished.

4. Planning area version update

According to actual requirements, the published planning region version can be inherited, and is modified, stored and published on the basis.

Planning version management

1. Planning version creation

Selecting a reference graph and a planning region version of a certain time section according to a planning task, and on the basis, establishing a planning version for a district by taking a county (region) as a unit, wherein the establishing comprises information such as a planning version name, a region where the version is located, establishing time, an establishing person and the like. After the creation of the planning version is completed, a planning solution can be created under the version.

2. Planning version release

And one planning version consists of one or a plurality of planning schemes, and after all planning schemes in the planning area are compiled, the confirmed planning schemes are selected and released.

3. Planning version modification

According to actual requirements, modification and updating can be carried out on the basis of the published planning versions, all planning schemes in any planning version and the following planning projects can be checked, and the planning versions are published after modification is completed.

4. Planning version store

And storing all planning schemes in any planning version, wherein the new planning version and the planning scheme cannot cover the original planning version and the planning scheme below the original planning version.

5. Planning version viewing

And setting the authority according to the jurisdiction region, and checking the development condition of the gridding planning versions of the unit and the lower-level unit.

3. Load prediction

The load prediction is a work for predicting the future value of the power load according to the past and the present of the power load, is an important process link of grid planning, and is an important operation means for connecting municipal control rules and power demand balance. Load prediction is developed in grid planning, firstly, data information in multiple aspects, including internal information and external information of power enterprises, information of relevant departments of national economy and the like, such as load, electric quantity, charging piles and distributed power supply data in grids, historical annual data of population, GDP, industrial electric quantity and the like in a planning area, is required to be researched and collected, data analysis is performed after arrangement and screening, and according to planning targets of near, medium and long periods, near-medium and distant load prediction work is developed by combining multiple power demand prediction models, and related work such as site selection and volume fixing of a transformer substation can be guided to be developed by prediction results.

Long-range load prediction

The long-range load prediction function mainly comprises the following steps: collecting functional land indexes, calculating unit block loads, setting parameters, and predicting results and displaying; the details are as follows.

1. And collecting the function land indexes.

The method comprises the steps of splitting the unit plot according to a government land planning map, and collecting large user information, charging pile information, distributed power supply information and multi-load information in the unit plot.

The method comprises the following steps of sequentially dividing a planning area range unit from small to large: unit block, power supply unit, power supply grid. The power supply grids are a county-level power supply area, a city-level power supply area and a provincial-level power supply area.

The content collection comprises the following steps: and the plot control rule planning information, the large user information of the plot and the distributed power supply information. The large user information includes: large user name, voltage class, installation capacity, commissioning time, historical annual maximum load; the distributed power supply information includes: power name, voltage class, power type, capacity, commissioning time; the multivariate load information includes: multiple load type, name, voltage class, storage capacity, peak power (capacity = peak power time), commissioning time.

The unit block display content includes: the system comprises the following components, namely, a land name, a land type, a power supply unit, a power supply region type, a floor area, an effective power supply area (the default is equal to the floor area and can be manually modified), a volume ratio, a building area and remarks (the remarks need to be maintained when controlling the land, and remark information is mainly described in the aspects of industrial characteristics and annual power consumption of large users).

The power supply unit displays content including: the method comprises the following steps of power supply unit name, power supply grids to which the power supply unit belongs, power supply area type, floor area, effective power supply area, building area, volume ratio, ratio of main land types in the power supply unit (the first two types with large default display ratio), and remarks.

The power grid display content comprises: power supply grid name, affiliated area, power supply area type, floor area, effective power supply area, building area, volume fraction and remarks.

Wherein, the volume fraction = building area/footprint. And for the area with only the master gauge and no control gauge, artificially giving the volume ratio according to the specific practical situation, and taking the highest value if the volume ratio value given by the unit block is an interval range. Typical bulk volume ratios are shown in table 3.1.

Table 3.1: typical plot volume ratio reference table

Right of land property code	Property of land	Volume fraction
			G1	Public greenbelt	0
M1	Industrial land	1.2
			U21	Land for public transport	0.2
U12	Power supply land	0.5

2. And calculating the load of the unit block.

The method integrates the large users, the charging piles, the distributed power supplies and the multi-element load data in the unit blocks, calculates the saturation annual load by using a space load prediction method, provides a basic data entry and maintenance function, supports the modification of the large users, the charging piles and the distributed power supplies in the unit blocks, and is convenient to correct the target annual load data.

The unit plot load calculation method selects three processing modes according to the type of the unit plot:

(1) Calculating the area of the existing land planning map by adopting a space load prediction method; the calculation formula method comprises the following steps:

when the plot only occupies the land area and has no volume fraction, selecting a construction land density index to calculate the saturation load of the plot; when a coincidence rate index exists, selecting a building density index to calculate the saturation load of the land; the calculation formula is as follows: x ₁ Index of area =;

acquiring the existing large user load of the plot, and calculating and installing the large user load; the calculation formula is as follows: x ₂ Load rate (= payload capacity);

calculating the highest load value of the charging piles of the land parcels; the calculation formula is as follows: x ₃ And (= slow charging vehicle position number + fast charging vehicle position number + unit load).

The three contents are superposed to obtain a long-range load target value, namely y = X ₁ +X ₂ +k ₁ *X ₃ Y is a target value of the perspective load, k ₁ The simultaneous rate coefficient of the charging pile load and the land saturation load is obtained.

(2) Calculating a soilless land planning map belonging to D and E type areas (D type land is special land, such as military land, foreign land and security land; E type land is water area and other land) according to a user average method; the calculation formula is as follows: y = k ₂ * N, N is the number of users in a block unit, k ₂ Is unit number of unit of long-term average highest load: (giving typical values according to local practical conditions);

(3) Calculating a soilless ground planning map belonging to a mature development area by adopting an average growth rate method; the calculation formula is y = a (1 + k) ₃ ) ⁿ A is the maximum load of the planned basic annual region, n is the time required for the region to reach saturation, k ₃ To develop an average of recent load increases in the mature region.

3. And (6) setting parameters.

(1) According to the standard document GB/T59023-2014 issued by the government, the contents in the urban electric load/load density index/planning unit construction land load index section are given 5 initial values in the order from small to large according to the load index range of various lands.

When the load prediction is performed by using the construction land load density method, the construction land load index is shown in table 3.2.

Table 3.2: load index of planning unit construction land

Classification of urban construction land	Unit construction land load index (kW/hm 2)
		Residential land (R)	100～400
Land for commercial service facility (B)	400～1200
		Land for public management and public service facilities (A)	300～800
Industrial land (M)	200～800
		Logistics storage land (W)	20～10
Land for road and traffic facilities (S)	15～30
		Public facility floor (U)	150～250
Land for green land and square (G)	10～30

The selection of the construction land load indexes of other various construction lands beyond the construction land in the table for planning units can be determined according to the specific conditions of the city.

When the unit building area load density index method is used, the building area load index is shown in table 3.3.

Table 3.3: load index for planning unit building area

The selection of the load density indexes of the special land and the planning reserved development reserve land can be determined by combining the local actual condition and the planning energy supply requirement according to the local condition.

When the coal-to-electricity region is involved, the index value standard is improved properly according to the local actual situation.

(2) The unit plot saturation load calculation method comprises the following steps: and the unit plot saturated load takes the larger value of the large user predicted value and the space load predicted value of the plot.

(3) The long-range load prediction calculation method comprises the following steps: and accumulating the saturation load values of the unit plots to which the power supply unit/power supply grid belongs. The new region concurrency rate is given according to the typical value of the local industry; the old city area synchronization rate is equal to the existing inter-industry synchronization rate. (the default value of the coincidence rate is 0.8, and the user is allowed to carry out single modification or batch modification on the land parcel except for the developed mature region, the other regions belong to a novel region, and the current method is suitable for the region with the land planning map).

4. And predicting and displaying the result.

The predicted result curve display interface can be divided according to the authority of the user, and two display types of a table and a curve are provided. The range sizes are referenced in table 3.4.

Table 3.4: display range corresponding to user authority

The map interface is presented in 2D in a style similar to thermodynamic diagrams.

The prediction results of a single power supply grid or power supply unit are displayed in a table mode and a curve mode, the prediction result value of the single grid or unit is displayed on a GIS map, and the load prediction value of the area can be displayed in a circled area.

(II) near-intermediate load prediction

The near-medium load prediction function mainly comprises the following steps: collecting basic data of the power grid, calculating historical data, selecting a load prediction method, and displaying a prediction result. The details are as follows.

1. And collecting basic data of the power grid.

The method mainly comprises the following steps: the distribution transformer in the unit block (the distribution transformer and the maximum load information of the line in the power supply unit/power supply grid and the corresponding time at the same time) and the load data of the line outlet switch 8760 point. Population, GDP, industrial power utilization (including: agriculture, forestry, animal husbandry, fishery, industry, transportation, storage and postal industry, information transmission, software and information technology service industry, wholesale and retail industry, lodging and catering industry, financial industry, land and house industry, leasing and business service industry, public service and management organization, and the like), industrial power utilization (including: first industry, second industry, third industry, urban and rural resident power utilization), and the like. The power grid equipment attribution can be classified, screened and summarized according to unit plots/power supply units/power supply grid attributes.

2. And (4) historical data calculation.

The correlation calculation method comprises the following steps: the method is based on a top-down proportion allocation method in saturated years, a top-down proportion allocation method based on distribution and transformation capacity, a bottom-up accumulation method based on line load and a bottom-up accumulation method based on distribution and transformation load. The details are as follows.

(1) A proportion allocation algorithm based on saturation year 'top-down': grid existing load = total load of the whole community of the area × proportion of total load of the area occupied by the grid in saturated years. The algorithm has the defects that the actual load ratio of the current state year is higher for a mature saturated grid, but the calculated current state load value ratio is lower because the grid load ratio in the region is possibly lower in the saturated year; for a slowly increasing area, the actual load ratio in the current year is lower, but the calculated current load value ratio is higher because the load ratio in the saturation year may be higher.

(2) Based on a distribution transformation capacity 'top-down' proportion allocation method: the grid existing load = total load of the whole area society x the proportion of the grid present distribution capacity to the total distribution capacity of the area. The algorithm has the disadvantage that the method may have partial errors due to different load rates of the distribution transformer.

(3) Based on the line load "bottom-up" cumulative method: superposing the data of all the 10 kilovolt lines 8760 of the power supply unit or the power supply grid to obtain the maximum value; data of direct supply load and distributed power supply of 35kV or more are required to be superposed; calculating the formula: the regional whole social load = regional 10kV network supply line load +10kV special line load +35kV and above direct supply load +10kV grid-connected power output + low-voltage grid-connected power output + spontaneous self-service power. The power supply amount of the network (of the equipment, the line, the power supply unit and the grid) is directly accumulated, and the download power and the upload power are respectively calculated and stored.

Wherein, each 10kv line needs to be added with an attribute tag to identify the power supply grid or power supply unit to which it belongs. The attribution relation is determined according to the distribution of the line configuration capacity (if the line has cross power supply units or power supply grids, the line belongs to which side with larger occupation ratio).

(4) Based on the 'bottom-up' cumulative method of distribution transformation: the 8760 point data of the power supply unit or the power supply grid are superposed and then the maximum value is obtained, and the 8760 point data are stored; data of large users and distributed power supplies with power of 35kV or more are required to be superposed. The power supply amount of the network (of the equipment, the line, the power supply unit and the grid) is directly accumulated, and the download power and the upload power are respectively calculated and stored.

3. And selecting a load prediction method.

(1) One or more averaging methods of the mainstream calculation methods are selected, including trend extrapolation (S-curve, average growth rate, binary regression, ternary regression, exponential growth), production value unit consumption, elastic coefficient, industrial electricity usage, maximum load utilization hours usage, and the like.

When a method fails or data is determined for a prediction, the method may not be selected. Different load prediction methods have different applicable scenarios, which are specifically shown in table 3.5.

Table 3.5: corresponding relation between load prediction algorithm model and scene

2) Hybrid load prediction method: as the mainstream algorithms have respective advantages and disadvantages, the method can give weights according to various prediction results, then accumulates the weights to obtain the load prediction results of the equipment or the area, and displays the load prediction results in a graph. The weight sum of the multi-curve method is 100%, and the proportion of the weight of each method is set by a planner.

4. And predicting and displaying the result.

The prediction result and the display part in the perspective load prediction can be referred to.

4. Constant volume site selection for transformer substation

Constant volume for transformer substation

1. The current year, the planning target year and the distant view year load of the planning area are collected, and data are derived from a load prediction result.

2. Referring to the "guidance of planning and designing technology of distribution network" to plan the regional load acceleration, the value range of the capacity-to-load ratio is set, as shown in table 4.1.

Table 4.1:110 kV-35 kV power grid capacity-load ratio selection range

Load increase situation	Slower growth	Moderate growth	Is increased more quickly
				Average annual load growth rate Kp	Kp≤7％	7％＜Kp≤12％	Kp＞12％
110 kV-35 kV electric network capacity-load ratio (recommended value)	1.8～2.0	1.9～2.1	2.0～2.2

3. Acquiring the existing capacity data, and calculating the upper limit and the lower limit of the newly added capacity

New capacity = network supply load of planned year capacity-current capacity.

4. And (3) setting selectable items, and selecting point distribution or expansion firstly (mainly adding new points for a fast-growing area and a mature saturated area (difficult point distribution or quick income), and mainly expanding main transformers for areas with load in the early stage of slow growth and difficult recovery of investment benefits for a long time under the condition of meeting the requirements).

5. The number of substations and the capacity are determined and the options are set with detailed reference to table 4.2.

Table 4.2: recommendation table for final capacity configuration of transformer substations in different power supply areas

In Table 4.2, the low voltage side of the main transformer is 10kV. For the power supply region determined by the load, a small-capacity transformer may be suitably employed. A. A 31.5MVA transformer (35 kV) in the class B region is suitable for use in the case of a power supply from a 220kV substation.

Site selection of transformer substation

1. The optimal site selection method (dotted area) is shown in fig. 2.

1) Through the load moment, the maximum 10kV power supply radius of the transformer substation in the planned area is calculated, the maximum power supply range of the existing transformer substation is determined, the distribution point of the newly-built transformer substation is beyond the range, and the range is gradually reduced along with the increase of the load.

2) Excluding the land type of the control gauge of the non-constructable transformer substation, comprising the following steps: lakes, roads, basic farmlands, ecological protection areas, etc.

3) And after the areas of the transformer substation which cannot be built are removed, the optimal site selection range of the transformer substation is narrowed, and the geometric center point of the site selection range is selected by combining boundary identification. And automatically giving a feasible point distribution area or an optimal point distribution suggestion, and finally, manually intervening to determine the site selection.

2. The selection method of the optimal station address (development starting area without distribution points) is shown in fig. 3.

For a development starting area without a transformer substation, the method is not applicable. The areas with the current load density higher than a certain value can be subjected to topology identification to obtain a central point a, the areas of all unit plots are subjected to topology identification to obtain a central point b, the center of a connecting line of a and b is taken as an optimal point arrangement suggestion (considering near-far stage load development), and finally, manual intervention is carried out to determine the address selection.

5. Analysis of 35kV and above power grid

(I) grid statistics

And (4) counting the type, the year, the planning property and the like of the power grid equipment, and checking related information according to a counting result. For example: for a line, the statistical information includes the line name, commissioning time, starting station, terminating station, etc.

(II) analysis of power grid topology

And analyzing the net racks of 35kV and above to find out the topological connection relation and the electrified range of the net racks, preparing data for typical wiring mode identification, and giving a detailed analysis result.

(III) analysis of Wiring Pattern

And identifying the wiring mode of the net rack of 35kV or above, finding out typical wiring modes such as radiation, chain type, ring type, T connection, pi connection and the like, and giving a detailed analysis result.

(IV) auxiliary electric calculation

The auxiliary electrical calculations include, but are not limited to, the following electrical calculations: (1) load flow calculation; (2) short circuit calculation; and (3) calculating the N-1 passing rate.

6. 10kV and above grid analysis

(I) grid statistics

And counting the type, the year, the planning property and the like of the power grid equipment, and checking related information according to a counting result. For example: for lines, the statistics include line name, time of day, type (overhead, cable), starting station, terminating station, etc.

(II) Power grid topology analysis

And carrying out topology analysis on the 10 (20, 6) kV net racks, finding out the topological connection relation and the electrified range of the net racks, preparing data for typical wiring mode identification, trunk analysis, longest path analysis, topological island analysis and segmented contact analysis, and giving out detailed analysis results.

(III) analysis of Wiring Pattern

And (3) carrying out wiring pattern recognition on the 10 (20, 6) kV net rack, finding out typical wiring modes of the overhead net, the cable net and the mixed net rack, and giving a detailed analysis result.

(IV) aiding electrical calculations

(V) grid evaluation

(1) Index system for evaluating city, county (district)

The method comprises six aspects including comprehensive indexes, power grid structure indexes, equipment level indexes, power supply capacity indexes, intelligent and green development indexes and power grid benefit indexes.

Wherein the comprehensive indexes comprise the average power failure time of a user, the comprehensive voltage qualification rate and the comprehensive line loss rate of 10kV or below. The power grid structure indexes comprise the average power supply radius of a 10kV line, the average number of sections of the 10kV overhead line, the contact rate of the 10kV line, the contact rate between 10kV line stations, the N-1 passing rate of the 10kV line and the standard wiring proportion of the 10kV line. The equipment level indexes comprise the average operation age of 10kV in-operation equipment, the cabling rate of a 10kV line, the insulation rate of a 10kV overhead line and the percentage of a 10kV high-loss distribution transformer. The power supply capacity indexes comprise the average value of the maximum load rate of a 10kV line, the occupation ratio of a 10kV heavy-load line, the average value of the maximum load rate of a 10kV distribution transformer, the occupation ratio of a 10kV heavy-load distribution transformer, the installation capacity of a 10kV line and the unsafe load of a 10kV line. The intelligent and green development indexes comprise distribution automation coverage rate, three-remote terminal occupation ratio, distribution transformer information acquisition rate, distributed power supply permeability and distributed power supply absorption rate. The power grid benefit indexes comprise unit investment increase and supply load and unit investment increase and sale electric quantity.

(2) Power distribution network power supply grid evaluation index system

The method also comprises six aspects including comprehensive indexes, power grid structure indexes, equipment level indexes, power supply capacity indexes, intelligent and green development indexes and power grid benefit indexes.

Wherein, the comprehensive index comprises the average power failure time of the household. The power grid structure indexes comprise the average power supply radius of the 10kV line and the N-1 passing rate of the 10kV line. The equipment level indexes comprise the cabling rate of a 10kV line and the insulation rate of a 10kV overhead line. The power supply capacity indexes comprise the ratio of a 10kV heavy-load line, the ratio of a 10kV heavy-load distribution transformer, the assembly capacity of a 10kV line and the unsafe load of the 10kV line. The intelligent and green development indexes comprise distribution automation coverage rate and distribution transformer information acquisition rate. The power grid benefit index comprises unit investment increase and supply load.

The embodiment integrates the data of the electric power related information system, forms a set of auxiliary tools with advanced technology, comprehensive functions and practicability for planning auxiliary calculation of the active power distribution network based on gridding, can meet the planning requirements of power distribution networks at all levels, can be popularized to A and B regions such as urban areas of six cities for use, provides data support and scientific basis for power grid planning decision making, realizes accurate planning, assists related technicians to make decisions, and achieves the purpose of improving the working efficiency.

EXAMPLE III

This embodiment is a computer-readable storage medium corresponding to the above-described embodiments, on which a computer program is stored, which program, when executed by a processor, performs the steps of:

sequentially dividing a preset planning area into a unit plot, a power supply unit and a power supply grid from small to large;

Further, sequentially dividing a preset planning area into a unit land block, a power supply unit and a power supply grid from small to large; the method specifically comprises the following steps:

determining a planning region according to a region corresponding to a county administrative district;

gridding and dividing the planning area to obtain more than one power supply grid;

dividing each power supply grid respectively to obtain more than one power supply unit;

and respectively dividing each power supply unit to obtain more than one unit plot.

Further, the load prediction of the planned area, and the load prediction result obtained specifically is:

performing long-term load prediction on the planning area to obtain long-term load of the planning area;

and performing near-medium term load prediction on the planning area to obtain a planning target annual load of the planning area and the current annual load of each power supply grid.

Further, the predicting the prospective load of the planning region to obtain the prospective annual load of the planning region specifically comprises:

respectively collecting functional land index information in each unit block, wherein the functional land index information comprises large user information, distributed power supply information and multi-element load information;

respectively calculating the saturation annual load of each unit plot according to the functional land use index information;

determining a saturation load value of a unit plot according to a maximum value of historical annual maximum load and saturation annual load in large user information of the unit plot;

calculating a distant view load predicted value of the power supply grid according to the saturated load value and a preset coincidence rate of each unit block in the power supply grid;

and calculating to obtain the long-term annual load of the planning area according to the long-term load predicted value of each power supply grid.

Further, the calculating the saturation annual load of each unit plot according to the functional land use index information specifically comprises:

if a corresponding land planning map exists in a unit plot, calculating the saturation annual load of the unit plot by a space load prediction method;

if a unit plot does not have a corresponding land planning map and the category of the unit plot is a special land or a water area or other lands, calculating the saturation annual load of the unit plot according to the number of users in the unit plot and a preset single-user-number perspective average highest load typical value;

and if the unit plot does not have the corresponding land planning map and belongs to a mature development area, calculating the saturated annual load of the unit plot by using an average growth rate method.

Further, the planning region is subjected to near-medium term load prediction to obtain a planning target annual load of the planning region and current annual loads of the power supply grids.

Collecting power grid basic data of a current year and a plurality of historical years of a power grid, wherein the power grid basic data comprise distribution transformer of each unit plot, maximum load information of a circuit and corresponding time of the maximum load information, and load data of a circuit outlet switch 8760 point;

calculating the total regional social load of the current year according to the power grid basic data of the current year;

calculating the current year load of a power supply grid according to the total regional social load of the current year, the proportion of the total load of the power supply grid in a saturated year to the total regional social load of the current year or the proportion of the distribution and transformation capacity of the power supply grid in the current year to the total distribution and transformation capacity of the power supply grid in the current year;

calculating the current annual load of the power supply area according to the current annual load of each power supply grid;

calculating the total regional social load of each historical year according to the basic data of the power grid of each historical year;

calculating the planned target annual load of the planned area through a near-middle period load forecasting method according to the total regional social load of the current year and each historical year, wherein the near-middle period load forecasting method comprises an annual average growth rate method, a binary regression method, a ternary regression method, an exponential growth method, an S curve model and a large user method.

Furthermore, the constant volume of the transformer substation is specifically determined as follows

Setting a value range of a capacity-load ratio according to a preset load acceleration of a planning area;

calculating a newly increased capacity range according to the planned target annual load, the capacity-to-load ratio value range and the existing capacity data of the planned area;

setting a constant volume strategy, wherein the constant volume strategy is point placement firstly or expansion firstly;

and determining the number and the capacity of the transformer substations according to the constant volume strategy, the voltage grade and the type of the power supply area.

Further, the site selection of the transformer substation specifically comprises:

judging whether a transformer substation exists in the planned area or not;

if the maximum power supply range exists, determining the maximum power supply range of the existing transformer substation in the planning area;

removing the area of the maximum power supply range and a preset area of the transformer substation which cannot be built in a planning area, and determining the site selection range of the transformer substation;

taking the geometric central point of the addressing range as a feasible point distribution area;

if the current year load and the current year load do not exist, calculating the current load density of each power supply grid according to the current year load and the current year area of each power supply grid in the planning area;

carrying out topology identification on the power supply grid with the current load density higher than a preset value to obtain a first central point;

carrying out topology identification on all power supply grids in the planned area to obtain a second central point;

taking the midpoint of the connecting line of the first central point and the second central point as a feasible point distribution area;

and determining the address of the newly-built substation according to the feasible stationing area and the perspective annual load of the planning area.

Further, the power grid analysis and the power grid evaluation of the planning area specifically include:

carrying out power grid statistics, power grid topology analysis, wiring mode analysis and auxiliary electrical calculation on a power grid with the voltage grade of 35kV or more in the planned area;

and carrying out power grid statistics, power grid topology analysis, wiring mode analysis, auxiliary electrical calculation and power grid evaluation on the power grid with the voltage grade of 10kV or below in the planned area.

In summary, the active power distribution network planning method and the storage medium based on meshing provided by the invention can realize active power distribution network space load prediction, determine the positions and capacities of the transformer substations to be built in the target year and the middle year according to the space load prediction result, realize multi-dimensional statistical analysis, topological analysis and wiring analysis of the power distribution network, and complete further electrical calculation analysis. Based on the data comprehensive analysis, scientific basis and effective support are provided for accurate planning and efficient investment of the power distribution network. The method can provide data support and scientific basis for power grid planning decision-making, realize accurate planning, assist relevant technicians to make decisions, and achieve the purpose of improving the working efficiency.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent changes made by using the contents of the present specification and the drawings, or applied directly or indirectly to the related technical fields, are included in the scope of the present invention.

Claims

1. An active power distribution network planning method based on gridding is characterized by comprising the following steps:

carrying out power grid analysis and power grid evaluation on the planning area;

the load prediction of the planned area is specifically as follows:

performing near-medium term load prediction on the planning area to obtain a planning target annual load of the planning area and the current annual load of each power supply grid;

the site selection of the transformer substation is specifically as follows:

judging whether a transformer substation exists in the planned area or not;

removing the area of the maximum power supply range and a preset area where a transformer substation cannot be built in the planned area, and determining the site selection range of the transformer substation;

2. The active power distribution network planning method based on meshing of claim 1, wherein the preset planning area is divided into a unit plot, a power supply unit and a power supply grid from small to large; the method specifically comprises the following steps:

determining a planning area according to an area corresponding to a county-level administrative district;

and dividing each power supply unit to obtain more than one unit block.

3. The active power distribution network planning method based on meshing of claim 1, wherein the perspective load prediction is performed on the planning region, and the perspective annual load of the planning region is obtained by:

respectively calculating the saturation annual load of each unit plot according to the functional land index information;

determining a saturated load value of a unit plot according to the maximum value of historical annual maximum load and saturated annual load in the large user information of the unit plot;

and calculating the long-term annual load of the planning area according to the long-term load predicted value of each power supply grid.

4. The active power distribution network planning method based on meshing of claim 3, wherein the calculating the saturation annual load of each unit plot according to the functional land use index information specifically comprises:

and if the unit plot does not have the corresponding land planning map and belongs to a mature development area, calculating the saturation annual load of the unit plot by using an average growth rate method.

5. The active power distribution network planning method based on meshing of claim 3, wherein the load prediction in the planning area in the near-middle period is performed to obtain a planning target annual load of the planning area and the current annual loads of the power supply grids specifically as follows:

6. The active power distribution network planning method based on meshing according to claim 5, wherein the volume determination of the transformer substation is specifically:

setting a value range of a capacity-to-load ratio according to a preset load acceleration rate of a planning area;

setting a constant volume strategy, wherein the constant volume strategy is point arrangement or expansion firstly;

7. The active power distribution network planning method based on meshing of claim 1, wherein the grid analysis and grid evaluation of the planning area specifically comprises:

performing power grid statistics, power grid topology analysis, wiring mode analysis and auxiliary electrical calculation on the power grid with the voltage class of 35kV or more in the planned area;

and carrying out power grid statistics, power grid topology analysis, wiring mode analysis, auxiliary electrical calculation and power grid evaluation on the power grid with the voltage grade of 10kV or below in the planning area.

8. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 7.