KR102026245B1 - Apparatus and method for designing offshore wind farm - Google Patents

Abstract

According to an aspect of the present invention, there is provided a method of designing an offshore wind farm, comprising: acquiring data related to the offshore wind farm design, and based on the acquired data, a plurality of offshore substation locations of the offshore wind farm Searching for a candidate group, based on the found plurality of candidate groups, designing an internal grid including at least one cable type and at least one cable connection type connecting the plurality of wind turbines of the offshore wind farm; and The method may include evaluating each of the designed inner grids and the outer grids according to the marine substation location.

Description

Apparatus and method for designing offshore wind farms {APPARATUS AND METHOD FOR DESIGNING OFFSHORE WIND FARM}

The technical idea of the present invention relates to an offshore wind farm design apparatus and method, and more particularly, to an offshore wind farm design apparatus and method that considers the substation location selection and the internal grid design.

Offshore wind power generation refers to a power generation method in which wind turbines are installed in water bodies such as lakes, fiord topography, and coastal areas, and the kinetic energy of the wind blowing there is converted into mechanical energy by rotating blades to obtain electricity.

The offshore wind farm for offshore wind power generation is larger than the onshore wind farm and is composed of tens to hundreds of wind turbines.

Offshore wind farms generate power from offshore wind turbines, which are collected through internal grids and then delivered to land via offshore substations and external grids.

Therefore, the design of offshore wind farm has various factors such as the optimal location selection of wind turbines considering the wind resources, the optimal layout selection of cable lines in the internal grid, the optimal location and configuration of substations, and the optimal configuration of the external grid. Should be considered.

In particular, since offshore wind farms require a lot of initial development costs due to the geographical characteristics of the sea, it is necessary to derive an optimal alternative for each problem mainly through economic evaluation such as initial investment cost and power loss cost. have.

The technical problem of the offshore wind farm design apparatus and method according to the technical idea of the present invention is to provide a design plan of the offshore wind farm complex considering the location of the offshore substation and the internal grid design.

The present invention aims to provide an optimal solution for the location of a substation where the sum of the initial investment cost, power loss cost, and supply disruption cost, which are the result of economic evaluation, reliability, supply disruption cost, cable line arrangement in the internal grid, and external grid configuration. .

The technical problem to be achieved by the offshore wind farm design device and method according to the technical idea of the present invention is not limited to the above-mentioned task (s), another task (s) not mentioned is to those skilled in the art from the following description It will be clearly understood.

According to an aspect of the present invention, there is provided a method of designing an offshore wind farm, including obtaining data related to the offshore wind farm design; Searching for a plurality of candidate groups for offshore substation locations of the offshore wind farm based on the obtained data; Designing an inner grid including at least one cable type connecting the plurality of wind turbines of the offshore wind farm and a connection type of the at least one cable based on the found plurality of candidate groups; And evaluating each of the designed inner grid and the outer grid according to the marine substation location.

According to an exemplary embodiment, the searching of the plurality of candidate groups for the substation location may include selecting an arbitrary location as an initial location of the substation, and in a plurality of directions with respect to the selected initial location. The method may include setting a position separated by a distance to the plurality of candidate groups, and comparing the plurality of candidate groups.

According to an exemplary embodiment, the searching of the plurality of candidate groups for the substation location may include selecting a position of one of the plurality of candidate groups as a result of the comparison, and in the plurality of aspects with respect to the selected position, The method may further include setting a position separated by the reference distance as a plurality of candidate groups and comparing the plurality of reset candidate groups.

According to an exemplary embodiment, the reference distance may be a distance that varies according to a search process for setting the set plurality of candidate groups.

According to an exemplary embodiment, designing the internal grid may include classifying the plurality of wind turbines into groups of the number of feeders according to the obtained data, and the plurality of wind turbines of the classified group. Calculating a length of a cable connecting the turbine to the wind turbines in the feeder, calculating a flow rate of flow through the cable of the calculated length, and based on the calculated length and flow rate, The method may include determining a cable to be applied to the inner grid.

According to an exemplary embodiment, the calculating of the length of the cable may include connecting a wind turbine located closest to the marine substation among a plurality of wind turbines in one of the classified groups, with the marine substation. And searching for an unconnected second wind turbine located closest to the already connected first wind turbine among the plurality of wind turbines in the one feeder; Connecting to the wind turbine.

According to an exemplary embodiment, the step of evaluating each of the designed inner grid and the outer grid according to the marine substation location may include the installation cost of the cable line included in the inner grid, the power loss occurring in the cable line and the power loss. Evaluating the cost of economics for the internal grid based on the cost of power loss.

According to an exemplary embodiment, the step of evaluating each of the designed inner grid and the outer grid according to the marine substation location may include supply disturbance power amount due to a failure that may occur in at least one of the plurality of wind turbines in the inner grid. The method may include evaluating a reliability cost for the internal grid based on the use of the feed site equipment according to the amount of supply site power.

According to an exemplary embodiment, the step of evaluating each of the designed inner grid and the outer grid according to the location of the substation of the substation may include the installation cost of the cable line included in the outer grid, the power loss occurring in the cable line and the power loss. Evaluating the cost of economics for the external grid based on the cost of power loss.

According to an exemplary embodiment, evaluating each of the designed inner grids and the outer grids according to the substation location may comprise the total rated capacity of the available cables in the outer grids and the outputs of the plurality of available wind turbines in the inner grids. Based on the step of evaluating the reliability cost for the outer grid.

According to an exemplary embodiment, the method may further include determining a design for the offshore wind farm based on the economic cost and the reliability cost of each of the evaluated inner and outer grids.

According to an exemplary embodiment, the determining of the design of the offshore wind farm may comprise a design in which the sum of the economic and reliability costs of each of the evaluated inner and outer grids is a minimum. Determining the design for may include.

According to another aspect of the present invention, an offshore wind farm unit includes a data input unit for acquiring data related to an offshore wind farm design; An offshore substation location alternative search unit for searching a plurality of candidate groups for offshore substation locations of the offshore wind farm based on the obtained data; Based on the searched plurality of candidate groups, generating an internal grid design alternative for designing an internal grid comprising at least one cable type connecting the plurality of wind turbines of the offshore wind farm and a connection type of the at least one cable part; An internal grid design alternative evaluator for evaluating the economics and reliability of the designed internal grid; And it may include an external grid evaluation unit for evaluating the economics and reliability for the external grid according to the location of the substation.

According to an exemplary embodiment, based on the economic and reliability evaluation results of each of the internal grid design alternative evaluation unit and the external grid evaluation unit, the final design proposal selection unit for determining the design for the offshore wind farm may be further included. have.

According to an exemplary embodiment, the final design plan selection unit may determine a design for which the sum of economic and reliability costs of each of the inner grid and the outer grid is the minimum, as a design for the offshore wind farm.

The offshore wind farm design apparatus and method thereof according to embodiments of the inventive concept may provide a design plan for the offshore wind farm in consideration of the location selection of the substation and the internal grid design.

The present invention can derive the optimal design for the location of the substation where the sum of initial investment cost, power loss cost, supply disturbance cost, which are the result of economic and reliability evaluation, the location of the cable substation in the internal grid, and the external grid configuration are minimized. have.

BRIEF DESCRIPTION OF THE DRAWINGS In order to better understand the drawings referred to herein, a brief description of each drawing is provided.
1 is a conceptual diagram showing the configuration of an offshore wind farm according to various embodiments of the present invention.
2 is a block diagram illustrating a configuration of an offshore wind farm design device according to various embodiments of the present disclosure.
3 is a block diagram illustrating a configuration of an offshore wind farm design device according to various embodiments of the present disclosure.
4 is a flowchart illustrating a method of operating an offshore wind farm design device according to various embodiments of the present disclosure.
5A to 5D are conceptual diagrams of a position submarine location search based on pattern search according to various embodiments of the present disclosure.
6 is a flowchart illustrating an internal grid design operation according to various embodiments of the present disclosure.
7 is an exemplary diagram of a plurality of groups of wind turbines classified according to various embodiments of the present invention.
8 is an exemplary view of a wind turbine connection according to various embodiments of the present invention.
9 illustrates an embodiment for calculating a maximum effective power amount of a cable according to various embodiments of the present disclosure.
10 is an exemplary view of a cable failure between the wind turbine according to various embodiments of the present invention.
11 illustrates a probability distribution of an output characteristic curve and a wind speed of a wind turbine according to various embodiments of the present disclosure.
12 shows reduced output characteristic curves of a wind turbine according to an embodiment of the invention.

The technical spirit of the present invention may be variously modified and have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail with reference to the accompanying drawings. However, this is not intended to limit the technical spirit of the present invention to specific embodiments, it should be understood to include all changes, equivalents, and substitutes included in the scope of the technical spirit of the present invention.

In describing the technical idea of the present invention, if it is determined that the detailed description of the related known technology may unnecessarily obscure the gist of the technical idea of the present invention, the detailed description thereof will be omitted. In addition, numerals (eg, first, second, etc.) used in the description process of the present specification are merely identification symbols for distinguishing one component from another component.

In addition, in the present specification, when one component is referred to as "connected" or "connected" with another component, the one component may be directly connected or directly connected to the other component, but in particular It is to be understood that, unless there is an opposite substrate, it may be connected or connected via another component in the middle.

In addition, the terms "~ part", "~ group", "~ ruler", "~ module", etc. described herein refer to a unit for processing at least one function or operation, which is a processor, a micro Processor, Application Processor, Micro Controller, Central Processing Unit (CPU), Graphics Processing Unit (GPU), Accelerate Processor Unit (APU), Digital Signal Processor (DSP), ASIC ( It may be implemented by hardware or software such as an application specific integrated circuit (FPGA), a field programmable gate array (FPGA), or a combination of hardware and software.

In addition, it is intended to clarify that the division of the components in the present specification is only divided by the main function of each component. That is, two or more components to be described below may be combined into one component, or one component may be provided divided into two or more for each function. Each of the components to be described below may additionally perform some or all of the functions of other components in addition to the main functions of the components, and some of the main functions of each of the components are different. Of course, it may be carried out exclusively by.

Hereinafter, embodiments according to the spirit of the present invention will be described in detail.

1 is a conceptual diagram showing the configuration of an offshore wind farm according to various embodiments of the present invention.

Referring to FIG. 1, the offshore wind farm 10 may include an offshore substation 100, an inner grid 200, and an outer grid 300.

The marine substation 100 may boost the power generated by the wind turbine and transfer the boosted power to the external grid 300.

A plurality of wind turbines are included in the inner grid 200, and the plurality of wind turbines WT may generate power using wind energy. The produced power is transferred to the marine substation 100 through the internal grid 200. Here, each group linked to the marine substation is called a feeder.

The external grid 300 may transmit power transmitted from the marine substation 100 to substations of the land. The grid connection point 390 may be a point at which the external grid 300 is connected to the substation of the land and the power facility of the land.

The offshore wind farm design apparatus and method according to various embodiments of the present disclosure may perform the offshore substation location selection, the inner grid design, and the outer grid design of the offshore wind farm 10. It will be described in detail below.

First, with reference to Figure 2 will be described the configuration of the offshore wind farm design device according to various embodiments of the present invention.

2 is a block diagram illustrating a configuration of an offshore wind farm design device according to various embodiments of the present disclosure.

Referring to FIG. 2, the offshore wind farm design device 400 includes a data input unit 410, an internal grid generation and evaluation unit 420, an external grid generation and evaluation unit 430, a final design plan selection unit 440, and The design algorithm end determination unit 460 may be included.

The data input unit 410 may receive data related to the offshore wind farm design.

For example, the data input unit 410 may receive at least one of wind turbine related data, cable related data, wind speed data, economic evaluation related data, reliability evaluation related data, marine substation related data, and internal grid related data.

Wind turbine related data may include data on the number and location of wind turbines, capacity and decay curves of the wind turbine.

Cable-related data may include data on allowable capacity for each cable type and resistance per unit length.

The wind speed data may include data on the wind speed probability distribution.

Economic assessment-related data may include data on the life expectancy and discount rate of wind farms.

Reliability assessment-related data may include data on failure rates and average repair periods per unit length of cable, and availability and unavailability of wind turbines.

The marine substation-related data may include data related to the initial position of the marine substation.

The internal grid related data may include data on the number of feeders.

The internal grid design and evaluation unit 420 may include an internal grid design alternative generation unit 421 and an internal grid design alternative evaluation unit 423.

The internal grid design alternative generation unit 421 may generate a candidate group for cable line arrangement in the internal grid 200.

The internal grid design alternative generation unit 421 may design an optimal internal grid 200 for a plurality of marine substation locations set in the marine substation location alternative search unit 433.

The internal grid design alternative evaluator 423 may evaluate the economics and reliability of the designed internal grid 200. For example, the internal grid design alternative evaluator 423 may evaluate the cable installation cost and the power loss cost as an economic evaluation factor, and calculate the use of the feeder equipment as the reliability evaluation factor.

The external grid design and evaluation unit 430 may include an external grid evaluation unit 431 and a marine substation location alternative search unit 433.

The external grid evaluator 431 may evaluate the economics and the reliability of the external grid 300.

The external grid evaluator 431 may evaluate the economics and reliability of the external grid according to the position of the marine substation and the type of the cable line.

The marine substation location alternative search unit 433 may select a candidate group for the location of the marine substation 100.

The marine substation location alternative search unit 433 can search for an optimal location of the marine substation 100 by gradually searching for a location better than the current location by searching around the current location based on a pattern search technique. have.

The final design plan selection unit 450 may select an optimal offshore wind farm design plan based on evaluation results of the inner grid and the outer grid. For example, the final design selection unit 450 may provide an alternative of minimizing the sum of the economic cost and the reliability cost as a result of the evaluation of the internal grid and the external grid (offshore substation location, cable line arrangement in the internal grid, external grid cable type). Etc.) can be selected as the optimal offshore wind farm design plan.

The design algorithm end determination unit 460 may determine whether the design algorithm that is repeatedly performed on each of the inner grid and the outer grid is terminated.

The above-described offshore wind farm design device 400 may be implemented with a processor, a memory, or the like.

3 is a block diagram illustrating a configuration of an offshore wind farm design device according to various embodiments of the present disclosure.

Referring to FIG. 3, the offshore wind farm design device 500 may include a processor 510, a memory 530, and an input module 550.

The processor 510 may control and perform overall operations of the offshore wind farm design device 500.

The processor 510 may include at least one processor or may be configured of a plurality of processors.

The memory 530 may store various information related to the operation of the offshore wind farm design device 500.

The input module 550 may receive various information and data.

The offshore wind farm design apparatus 500 may perform operations related to offshore wind farm design using instructions driven by the processor 510 and the memory 530 described above.

Accordingly, operations performed by the components included in the above-described offshore wind farm design device 400 may be performed by instructions executed by the processor 510 and the memory 530.

On the other hand, the offshore wind farm design device 500 may include a variety of configurations in addition to the above-described configuration. For example, the offshore wind farm design device 500 may include a communication module for wired and wireless communication.

Referring to Figure 4, the operation of the offshore wind farm design device will be described.

4 is a flowchart illustrating a method of operating an offshore wind farm design device according to various embodiments of the present disclosure.

Referring to FIG. 4, the offshore wind farm design devices 400 and 500 may acquire data related to the offshore wind farm design (S110).

The data input unit 410 or the input module 550 of the offshore wind farm design devices 400 and 500 may receive various data related to the offshore wind farm design.

For example, the offshore wind farm design devices 400 and 500 may include wind turbine related data, cable related data, wind speed data, economic evaluation related data, reliability evaluation related data, marine substation related data, and internal grid related data. At least one may be input.

The offshore wind farm design devices 400 and 500 may search for alternatives to the offshore substation location (S120).

The marine substation location alternative search unit 433 may gradually search for a better location than the current location by searching around the current location based on a pattern search technique. Here, the current position may mean the position of the marine substation set as the candidate group.

Accordingly, the marine substation location alternative search unit 433 may search for the optimal location of the marine substation.

The substation location search based on the pattern search of the marine substation location alternative search unit 433 will be described with reference to FIGS. 5A to 5D.

5A to 5D are conceptual diagrams of a position submarine location search based on pattern search according to various embodiments of the present disclosure.

Referring to FIG. 5A, the marine substation position alternative search unit 433 sets positions spaced apart by the same distance for eight directions around the A 301 which is the initial position of the marine substation as a candidate group for the marine substation position. Can be.

The marine substation location alternative search unit 433 may perform economic and reliability evaluation on each of the eight candidate groups, and compare whether there is a better location than the current location and location A 301.

For example, the marine substation location alternative search unit 433 may determine that the location B 302 is better than the current location and location A 301 based on the comparison result. In addition, the marine substation location alternative search unit 433 may set the location B 302 as a new reference location of the peripheral search.

Referring to FIG. 5B, the marine substation position alternative search unit 433 may set candidate groups in eight directions in the same way around the new reference position, position B 302. At this time, the marine substation location alternative search unit 433 may set a candidate group in eight directions with a search distance having a distance twice as large as before with respect to the position B 302. In addition, the marine substation location alternative search unit 433 may perform economic and reliability evaluations on the eight candidate groups, and if there are no location candidates better than the current location and location B 302, the navigation substation location search unit 433 may search again by reducing the search distance. The process of performing the peripheral search after adjusting the search distance may be repeated.

Here, the marine substation location alternative search unit 433 may adjust the search distance based on the evaluation result of the candidate group. For example, the marine substation location alternative search unit 433 may reduce the search distance if the result of the evaluation of the candidate group is not found, and may increase the search distance when the result is found. In addition, the distance, magnification, and the like, to which the marine substation position alternative search unit 433 adjusts the search distance may be variously set.

Referring to FIG. 5C, the marine substation position alternative search unit 433 may set eight candidate groups having reduced search distances based on the current position and the position B 302. And the substation location alternative search unit 433 can find the current location, location C 303 which is better than location B 302. The position C 303 may be a criterion for selecting a position candidate group in the next search.

Referring to FIG. 5D, the marine substation location alternative search unit 433 may set candidate groups in eight directions based on the position C 303. Here, the marine substation position alternative search unit 433 may set a candidate group as a search distance at the minimum search, and repeat the search. The marine substation location alternative search unit 433 may search again by adjusting the search distance according to the search result.

The marine substation location alternative search unit 433 narrows the search interval to search for a better location, and if the search is possible to find a better location even though the search is performed up to the minimum search distance, the marine substation location ends. It can be determined as the optimal position of.

The above-described marine substation location alternative search may be performed simultaneously with the process of generating and evaluating the internal grid design alternative described later. Thus, the offshore wind farm design apparatus 400, 500 may select the final alternative by designing and evaluating the inner grid for each of the candidate groups for the offshore substation location described above for the inner grid design to be described later. Hereinafter, it will be described again.

Reference is again made to FIG. 4.

Referring to FIG. 4, the offshore wind farm design devices 400 and 500 may generate an internal grid design alternative for each position candidate group set by the offshore substation location alternative search unit 433 (S130).

In detail, the internal grid design alternative generation unit 421 may search for cases in which the plurality of wind turbines may be classified into groups as many as the number of input feeders. And the internal grid design alternative generation unit 421 connects the wind turbines in each feeder to the minimum cable length for the classified wind turbines, calculates the amount of tidal current that can flow through the connected cable line, Cables suitable for the current flow rate can be selected.

This will be described in detail with reference to FIG. 6.

6 is a flowchart illustrating an internal grid design operation according to various embodiments of the present disclosure.

Referring to FIG. 6, the internal grid design alternative generation unit 421 obtains information on the position of the marine substation and the positions of the plurality of wind turbines, and applies a K-clustering method to the plurality of grids. The wind turbines may be classified into groups as many as k of input feeders. The classified groups can then be considered initial in generating various cases for wind turbine classification.

Here, the K-clustering method can be expressed by the following equation.

는 i번째 피더에 속하는 풍력 터빈들의 각도의 평균값을 의미한다.In the above equation, FD _i is a set including wind turbines belonging to the i-th feeder, k is the number of feeders, θ _j is the angle of the j-th wind turbine calculated from the right side of the offshore substation,

Denotes an average value of angles of the wind turbines belonging to the i-th feeder.

An embodiment will be described with reference to FIG. 7.

7 is an exemplary diagram of a plurality of groups of wind turbines classified according to various embodiments of the present invention.

Referring to FIG. 7, the internal grid design alternative generation unit 421 has three feeders and four wind turbines, and the first wind turbine WT 1 to twelfth wind turbine ( The twelve wind turbines of WT 12 can be classified into three groups. The internal grid design alternative generation unit 421 is the first wind turbine (WT 1), the second wind turbine (WT 2), the third wind turbine (WT 3) and the fourth wind turbine (WT 4) to the first feeder. The fifth wind turbine (WT 5), the sixth wind turbine (WT 6), the seventh wind turbine (WT 7), and the eighth wind turbine (WT 8) are classified as second feeders, and the ninth wind turbine. The WT 9, the tenth wind turbine WT 10, the eleventh wind turbine WT 11, and the twelfth wind turbine WT 12 may be classified as third feeders.

The internal grid design alternative generation unit 421 may design the sorted wind turbines by using a genetic algorithm.

For example, the internal grid design alternative generation unit 421 may generate an information table for wind turbines belonging to each feeder, as shown in Table 1 below.

Feeder length One 2 3 4 5 6 Feeder 1 One 2 3 4 0 0 Feeder 2 5 6 7 8 0 0 Feeder 3 9 10 11 12 0 0

In Table 1 above, the length of the feeder is determined by the following formula by the rated capacity of the cable and the wind turbine, 0 means empty space.

The internal grid design alternative generation unit 421 may apply a crossover operator of a genetic algorithm.

In detail, the internal grid design alternative generation unit 421 may randomly select two nearby feeders and randomly select one of the elements of the two selected feeders from the wind turbine information table. The internal grid design alternative generation unit 421 may change the positions of two randomly selected wind turbines.

For example, referring to Table 2 below, the internal grid design alternative generation unit 421 selects feeder 1 and feeder 2, and in (1,4) and (2,2), respectively, in the feeder wind turbine information table. The corresponding element, wind turbine 4 and wind turbine 6 can be selected. In addition, the internal grid design alternative generation unit 421 may swap positions of the selected wind turbine 4 and wind turbine 6. Accordingly, wind turbines 1, 2, 3, and 6 belong to the feeder 1, and wind turbines 4, 5, 7, and 8 belong to the feeder 2.

Feeder length One 2 3 4 5 6 Feeder 1 One 2 3 4 → 6 0 0 Feeder 2 5 6 → 4 7 8 0 0 Feeder 3 9 10 11 12 0 0

The internal grid design alternative generation unit 421 may apply a mutation operation of the genetic algorithm.

Specifically, the internal grid design alternative generation unit 421 randomly selects two adjacent feeders, and randomly selects one of the elements of the first selected feeder among the two selected feeders in the wind turbine information table. Can be. In addition, the internal grid design alternative generation unit 421 may insert the randomly selected wind turbine later into the empty space of the selected feeder. The internal grid design alternative generation unit 421 may terminate the deformation operator operation when there is no empty space in the selected feeder later.

Referring to Table 3, one embodiment will be described.

Referring to Table 3 below, the internal grid design alternative generation unit 421 may select the feeder 2 and the feeder 3. The internal grid design alternative generation unit 421 may select the 9th wind turbine corresponding to (3,1) among the elements corresponding to the first feeder 3 selected from the selected feeder 2 and the feeder 3 from the wind turbine information table. have. In addition, the internal grid design alternative generation unit 421 may input 9 into the empty space of the feeder 2.

Feeder length One 2 3 4 5 6 Feeder 1 One 2 3 4 0 0 Feeder 2 5 6 7 8 0 → 9 0 Feeder 3 9 10 11 12 0 0

As such, the internal grid design alternative generation unit 421 may apply the genetic algorithm based on the wind turbine classification result obtained by applying the K-clustering technique, and may generate various cases for the classification of the wind turbine. .

Reference is again made to FIG. 6.

The internal grid design alternative generation unit 421 may connect the wind turbines in the feeder with the minimum cable length with respect to the classified wind turbines (S133).

The internal grid design alternative generation unit 421 may connect the wind turbines so that the length of the cable line is minimized by using the following equation.

Here, L _ij means the distance between wind turbines i, j belonging to the k-th feeder.

Specifically, the internal grid design alternative generation unit 421 may connect the wind turbine located nearest to the marine substation 100 in the k-feeder with the marine substation 100. The internal grid design alternative generation unit 421 may search for the wind turbine having the closest distance to the already connected wind turbines among the wind turbines remaining in the k feeder, and connect the two found wind turbines to each other. And the internal grid design alternative generation unit 421 may repeat the wind turbine search and connection until there are no wind turbines remaining in feeder k. The internal grid design alternative generation unit 421 may repeat the above-described process for all feeders. This process may be referred to as a minimum spanning tree.

A detailed connection example will be described with reference to FIG. 8.

8 is an exemplary view of a wind turbine connection according to various embodiments of the present invention.

Referring to FIG. 8 (a), with respect to the wind turbine classification result shown in Table 2, the internal grid design alternative generation unit 421 applies the above-described minimum spanning tree to apply the wind turbine and offshore substation 100. You can check the result of the connection. As shown in FIG. 8 (a), the internal grid design alternative generation unit 421 may check the results of connecting the wind turbines by cables in the feeders 1, 2, and 3, respectively. This can be shown in Table 4 below.

Feeder 1 Feeder 2 Feeder 3 0 4 0 8 0 12 4 3 8 7 12 11 2 3 7 6 11 10 One 3 6 5 10 9

Referring to FIG. 8 (b), with respect to the wind turbine classification result shown in Table 3, the internal grid design alternative generation unit 421 applies the above-described minimum spanning tree to apply the wind turbine and offshore substation 100. You can check the result of the connection.

Reference is again made to FIG. 6.

The internal grid design alternative generation unit 421 may select a cable type of a cable connected between the wind turbines (S135).

In detail, the internal grid design alternative generation unit 421 may calculate the maximum amount of effective power flowing through the cable in order to select a cable for connection between two wind turbines or between the wind turbine and the marine substation 100.

This will be described with reference to FIG. 9.

9 illustrates an embodiment for calculating a maximum effective power amount of a cable according to various embodiments of the present disclosure.

Referring to FIG. 9, the internal grid design alternative generation unit 421 may represent a sequence pair indicating a connection relationship of the wind turbine in the feeder as shown in FIG. 9 as shown in Table 5 below. The internal grid design alternative generation unit 421 may calculate the direction of the effective power flow and the maximum amount of effective power flowing through the cable, based on the ordered pair as shown in Table 5.

i

i j

0 (Marine Substation) One One 2 2 3 2 5 3 4 5 6

Specifically, the internal grid design alternative generation unit 421 may select an ordered pair including a number appearing only once from an ordered pair representing an ordered pair of a wind turbine and a marine substation connected to each other in the feeder.

For example, (i, j) ¹ = (3, 4), (5, 6), and the superscript means a turn to select an ordered pair.

In addition, the internal grid design alternative generation unit 421 may define a wind turbine of a number that appears only once as “From WT” and a remaining number of wind turbines as “To WT” to define a flow direction of active power. .

The internal grid design alternative generation unit 421 is a '1' (the number of cumulative wind turbines that send the generated power through the cable) to the corresponding position in the Maximum Power Flow (MPF) matrix as shown in Table 6 below. Can be entered.

(a) + (b) OS / S "To WT" 0 One 2 3 4 5 6 OS / S 0 "From WT" One 2 3 4 One 5 6 One

The internal grid design alternative generation unit 421 may delete the corresponding order pair from Table 6 after inputting the number, excluding the input number pair from consideration.

The internal grid design alternative generation unit 421 may select an ordered pair having a wind turbine number appearing only once of the remaining ordered pairs. For example, it may be (i, j) ¹ = (2, 3), (2, 5).

The internal grid design alternative generation unit 421 may input the cumulative number of wind turbines that deliver power through the cable according to the following equation in the MPF matrix as shown in Table 7 below.

Where MPF (i, j) ^iter refers to the element at position (i, j) of the MPF matrix during the selection of the iter th wind turbine sequence pair, between the two turbines in the direction from the i th wind turbine to the j th wind turbine The cumulative number of wind turbines that deliver power through the cable.

(a) + (b) OS / S "To WT" 0 One 2 3 4 5 6 OS / S 0 "From WT" One 2 3 1 + 1 4 One 5 1 + 1 6 One

In addition, the internal grid design alternative generation unit 421 may repeat the above-described process until all remaining order pairs disappear. The final result of the MPF matrix is shown in Table 8 below.

(a) + (b) OS / S "To WT" 0 One 2 3 4 5 6 OS / S 0 "From WT" One 6 2 5 3 2 4 One 5 2 6 One

The internal grid design alternative generation unit 421 may calculate the maximum active power flowing through each cable by multiplying the MPF matrix result by the wind turbine's rated capacity. In addition, the internal grid design alternative generation unit 421 may determine a cable type that can satisfy the maximum active power.

Reference is again made to FIG. 4.

The offshore wind farm design devices 400 and 500 may evaluate the generated internal grid (S140).

The internal grid design alternative evaluator 423 may evaluate the generated internal grid.

In detail, the internal grid design alternative evaluator 423 may evaluate the economics and reliability of the generated internal grid. For example, the internal grid design alternative evaluator 423 may evaluate the cable installation cost and the power loss cost as an economic evaluation factor, and calculate the use of the supply site equipment as the reliability evaluation factor.

The internal grid design alternative evaluator 423 may calculate the cable installation cost CC _IG in the internal grid through the following equation.

Where L _ij is the length of the cable line and CT _ij is the installation cost per unit length of the cable type selected between the ij sections.

The internal grid design alternative evaluator 423 may calculate the annual power loss amount PL _ij per cable and the total power loss cost PLC _IG in consideration of the following assumptions.

-Cable failures are not taken into account, only the available state of the wind turbine (normal operation, failure).

-All cable voltages are assumed to be rated.

The internal grid design alternative evaluator 423 may calculate the current I ² _ij (n _f ) flowing in the ij section through the following equation.

Where n _ij is the number of wind turbines accumulated in the cable of section ij, and n _f is the number of wind turbines in a fault state among n _ij . And V _IG is the rated voltage of the cable in the internal grid, pf is the power factor, P _R is the rated output of the wind turbine, A is the availability of the wind turbine, and U is the availability of the wind turbine.

The internal grid design alternative evaluator 423 may calculate the power loss in the cable of the ij section considering the failure of the wind turbine using the current calculated above. Specifically, the internal grid design alternative evaluator 423 may calculate the power loss PL _ij by using the following equation.

Where R _ij is the resistance per unit length of the cable line applied to section ij, δ is the Loss Load Factor, and T is 8760 hours.

Since the annual power loss is calculated as the sum of the power losses in all cables, the internal grid design alternative evaluator 423 may calculate the annual power loss cost PLC _IG based on the following equation.

Where π is the selling price of the electricity produced at the wind farm.

The internal grid design alternative evaluator 423 may evaluate the reliability evaluation of the internal grid by estimating the supply disturbance power and the supply site equipment, which is the amount of power not transmitted to the land system due to the failure of the cable and the wind turbine.

Specifically, when a failure occurs in the wind turbine, supply disturbance power is generated as much as the output of the wind turbine. However, if a failure occurs in the cable of the ij section, supply disturbance power is generated as much as the output of all the wind turbines transmitting power through the cable. This will be described with reference to FIG. 10.

10 is an exemplary view of a cable failure between the wind turbine according to various embodiments of the present invention.

For example, as shown in FIG. 10, when a failure occurs in the cable between the third wind turbine WT3 and the fourth wind turbine WT4, the first wind turbine WT1 and the second wind turbine WT2 are damaged. a third wind turbine _{(WT3) (n 34 = 3} ) , the output of the wind turbine in a wind turbine as many as the number of available (n ₃₂ -n _f, (stage, n ≤3 _f)) of the electric power is supplied hindrance.

Since cable failures are very low compared to failures of wind turbines, it can be assumed that only a single failure occurs for the cable and a plurality of failures occur for the wind turbine. In addition, since the failure of the cable and the wind turbine are independent of each other, the internal grid design alternative evaluation unit 423 calculates the net number of wind turbines, n _NU, which cannot be transmitted due to the two types of failures as shown in the following equation. I can express it.

Where N _WT is the total number of wind turbines in offshore wind farms.

The internal grid design alternative evaluator 423 determines the probability that the net number of wind turbines that cannot transmit power is n _NU when a failure occurs in the cable of section ij, and when the n _f wind turbines are in a broken state. The same formula can be used.

Where r is the average length of repair in the event of a cable failure and λ is the failure rate per unit length of the cable.

The internal grid design alternative evaluator 423 may calculate an annually supplied energy consumption (EENU) using the following equation.

Where EE is the expected output of an individual wind turbine.

11 illustrates a probability distribution of an output characteristic curve and a wind speed of a wind turbine according to various embodiments of the present disclosure.

As shown in FIG. 11, the expected output of the individual wind turbine may be calculated by the internal grid design alternative evaluator 423 using the following equation, using the output characteristic curve of the wind turbine and the probability distribution of the wind speed.

It can be assumed here that the expected output of all wind turbines is the same.

The internal grid design alternative evaluation unit 423 may calculate the annual supply disruption cost RC _IG by the following formula.

Cable installation costs are only incurred in the early stages of cable line layout in the internal grid, but annual power loss costs and supply site equipment costs are incurred annually.

Accordingly, the internal grid design alternative evaluator 423 may calculate the final investment cost (CC _IG ) for the internal grid by the net present value of annual power loss cost and supply site equipment.

Where lt is the life expectancy of the offshore wind farm and ir is the discount rate for calculating the net present value.

Through this process, the internal grid design alternative evaluator 423 may evaluate the economics and reliability of the generated internal grid.

Reference is again made to FIG. 4.

Offshore wind farm design device (400, 500) can evaluate the generated external grid (S150).

The external grid evaluator 431 may evaluate the generated external grid.

In detail, the external grid evaluation unit 431 may perform economic and reliability evaluation according to the cable configuration in the external grid.

The external grid evaluator 431 may calculate the cable installation cost in the external grid by using the following equation.

Where n _EG is the number of cable lines in the outer grid, L _EG is the length of the cable in the outer grid, and CT _EG is the installation cost per unit length depending on the cable type used in the outer grid.

The external grid evaluator 431 may calculate the power loss cost of the cable in the external grid by using the following equation. This may be similar to the case of the inner grid.

Where R _EG is the resistance per unit length according to cable type and V _EG is the rated voltage of the outer grid.

The external grid evaluator 431 may calculate supply disturbance power for cable failure in the external grid in consideration of the following two situations.

-The cables available in the external grid can withstand the output of the available wind turbines

-The cables available in the external grid cannot afford the output of the available wind turbines.

12 shows reduced output characteristic curves of a wind turbine according to an embodiment of the invention.

First, in the latter of the above two situations, it can be assumed that the wind turbines limit the output of the wind turbines as shown in FIG. 12 to transmit power below the total rated capacity of the available cables. In FIG. 12, the dotted line is the output characteristic curve of the wind turbine, and the solid line is the output characteristic curve when the output of the wind turbines is to be reduced.

)를 아래와 같이, 두 가지 상황에 대해 표현할 수 있다.The external grid evaluation unit 431 has a limited rated output (

) Can be expressed for two situations:

Where CB _EG is the rated capacity of the cable type used in the external grid.

In addition, the external grid evaluation unit 431 may calculate the probability of occurrence (Pr (n _f )) of the failure of the cable and the wind turbine in the external grid as follows.

The external grid evaluation unit 431 may calculate the supply disruption cost RC _EG , which is the reliability cost of the external grid, by the following formula.

는 제한된 정격 출력을 고려하여, 다시 산정된 풍력 터빈의 기대 출력을 의미하고, 외부 그리드 평가부(431)는 아래 수식으로 이를 계산할 수 있다.here

Denotes the expected output of the wind turbine, which is again calculated in consideration of the limited rated power, and the external grid evaluation unit 431 may calculate this by the following equation.

Through this process, the external grid evaluator 421 may evaluate the economics and reliability of the generated external grid.

Reference is again made to FIG. 4.

The offshore wind farm design devices 400 and 500 may select a final alternative based on the evaluation of the inner grid and the outer grid (S160).

The final design plan selector 450 may determine a final alternative to the offshore wind farm design based on evaluations performed by each of the internal grid design alternative evaluator 423 and the external grid evaluator 431. This determination may be determined according to the determination of whether the design algorithm end determination unit 460 repeats the above-described process.

Specifically, the above-described inner grid design and outer grid design may be performed at the same time, and evaluation for each of the designed inner grid and outer grid may also be performed at the same time. The design algorithm end determination unit 460 may determine whether the internal grid and the external grid are terminated by repeating the design and evaluation. Therefore, the above-described processes may be repeated until the design algorithm end determination unit 460 determines that the end of the repetition is performed. Can be judged.

The final design selection unit 450 may select the final alternative based on the calculated costs for the internal grid design and the calculated costs for the external grid design. For example, the final design selection unit 450 may select an alternative in which the sum of the calculated costs is the minimum as the final alternative. In one embodiment, the final design selection unit 450, the location of the offshore substation where the sum of the initial investment cost, power loss cost, supply disruption cost, which is the result of economic and reliability evaluation, cable line arrangement in the internal grid and the external grid The optimal solution for the configuration can be determined.

Accordingly, the offshore wind farm design apparatus 400 or 500 according to various embodiments of the present disclosure may perform a comprehensive design considering both economical efficiency and reliability for each of the inner grid and the outer grid. In particular, the offshore wind farm design apparatus 400, 500 according to various embodiments of the present invention is a marine substation having a great influence on the cable line arrangement problem in the inner grid and the cable line arrangement problem in the inner grid when designing the inner grid; By using an iterative algorithm for the positioning problem, it is possible to establish an optimal design considering two problems.

As mentioned above, although the technical idea of the present invention has been described in detail with reference to a preferred embodiment, the technical idea of the present invention is not limited to the above embodiments, and having ordinary skill in the art within the scope of the technical idea of the present invention. Many modifications and variations are possible.

10: Offshore wind farm
100: substation
200: internal grid
300: outer grid
390: grid connection point
400: offshore wind farm design device
410: data input unit
420: internal grid generation and evaluation unit
421: Generation of an internal grid design alternative
423: Internal grid design alternative evaluation unit
430: external grid generation and evaluation unit
431: external grid evaluation unit
433: marine substation location alternative search unit
450: Final design proposal selection unit
460: design algorithm end determination unit
500: offshore wind farm design device
510: processor
530: memory
550: input module

Claims (15)

In the offshore wind farm design method,
Acquiring data related to the design of the offshore wind farm;
Setting a plurality of candidate groups for the offshore substation locations of the offshore wind farm in the offshore wind farm based on the obtained data;
Designing, for each of the plurality of candidate groups, an inner grid including at least one cable type connecting the plurality of wind turbines of the offshore wind farm and a connection type of the at least one cable; And
Evaluating each of the candidate groups, each of the designed inner grids and outer grids according to the marine substation location.
Offshore wind farm design method.
The method of claim 1,
The step of setting a plurality of candidate groups for the marine substation location is
Selecting an arbitrary position as an initial reference position of the marine substation;
Setting the plurality of candidate groups to positions spaced apart from the initial reference position by the reference distance in the plurality of directions;
Offshore wind farm design method.
The method of claim 2,
The step of setting a plurality of candidate groups for the marine substation location is
Reselecting a position of any one of the plurality of candidate groups as the reference position based on the evaluation result for each of the plurality of candidate groups;
Setting the plurality of candidate groups back to the plurality of candidate positions away from the reselected reference position in the plurality of directions;
Offshore wind farm design method.
The method according to claim 2 or 3,
The reference distance is a distance that varies according to a setting process for setting the plurality of candidate groups.
Offshore wind farm design method.
The method of claim 1,
Designing the inner grid
Classifying the plurality of wind turbines into groups of the number of feeders according to the obtained data;
Calculating a length of a cable connecting the plurality of wind turbines in the classified group to wind turbines in the feeder;
Calculating the amount of algae flowing through the calculated length of cable;
Determining a cable to be applied to the inner grid based on the calculated length and tidal flow amount;
Offshore wind farm design method.
The method of claim 5,
Calculating the length of the cable
Connecting a wind turbine located closest to the marine substation among a plurality of wind turbines in one of the classified groups, with the marine substation;
Searching for a second unconnected wind turbine located at a closest distance to a first connected wind turbine among the plurality of wind turbines in the one feeder;
Coupling the searched second wind turbine to the first wind turbine.
Offshore wind farm design method.
The method of claim 1,
Evaluating each of the designed inner grid and the outer grid according to the marine substation location is
Evaluating the economic cost for the inner grid based on the installation cost of the cable line included in the inner grid, the power loss occurring in the cable line and the power loss cost according to the power loss.
Offshore wind farm design method.
The method of claim 1,
Evaluating each of the designed inner grid and the outer grid according to the marine substation location is
Evaluating a reliability cost for the inner grid based on the amount of supply disturbances that may occur in at least one of the plurality of wind turbines in the inner grid and the use of supply branch equipment in accordance with the amount of supply disturbance;
Offshore wind farm design method.
The method of claim 1,
Evaluating each of the designed inner grid and the outer grid according to the marine substation location is
Evaluating the economic cost for the outer grid based on the installation cost of the cable line included in the outer grid, the power loss occurring in the cable line and the power loss cost according to the power loss.
Offshore wind farm design method.
The method of claim 1,
Evaluating each of the designed inner grid and the outer grid according to the marine substation location is
Evaluating a reliability cost for the outer grid based on the total rated capacity of available cables in the outer grid and the output of the plurality of available wind turbines in the inner grid.
Offshore wind farm design method.
The method of claim 1,
Determining a design for the offshore wind farm based on the economic and reliability costs of each of the evaluated inner and outer grids;
Offshore wind farm design method.
The method of claim 11,
Determining a design for the offshore wind farm
Determining a design of the offshore wind farm as the designation of the sum of economic and reliability costs of each of the evaluated inner and outer grids is minimal.
Offshore wind farm design method.
A data input unit for acquiring data related to offshore wind farm design;
An alternative substation location search unit for setting positions away from a current reference location by a reference distance in a plurality of directions to a plurality of candidate groups for the substation location of the offshore wind farm;
An internal grid design alternative generation unit for designing an inner grid including at least one cable type connecting the plurality of wind turbines of the offshore wind farm and a connection form of the at least one cable for each of the plurality of candidate groups;
An internal grid design alternative evaluator for evaluating the economics and reliability of the designed internal grid for each of the plurality of candidate groups; And
An external grid evaluation unit for evaluating the economics and reliability of the external grid according to the position of the marine substation for each of the plurality of candidate groups.
Offshore wind farm design device.
The method of claim 13,
And further including a final design plan selection unit for determining a design for the offshore wind farm based on the economic and reliability evaluation results of each of the internal grid design alternative evaluator and the external grid evaluator.
Offshore wind farm design device.
The method of claim 14,
The final design proposal selection unit
The design of the offshore wind farm is determined to have a design in which the sum of economic and reliability costs of each of the inner grid and the outer grid is minimal.
Offshore wind farm design device.

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