KR102110102B1 - Optimal arrangement system for internal grid of offshore wind farm - Google Patents

Abstract

The present invention relates to an optimal arrangement system for an offshore wind power generation complex, an expected power calculation unit for estimating expected output of a wind turbine and a wind power generation complex, and an alternative selection unit for selecting at least one alternative for the construction of an internal grid. , Economic evaluation unit for evaluating the economics for each of the selected alternatives, reliability evaluation unit for evaluating the reliability for each of the selected alternatives, and calculating the total investment cost and power loss cost for the economic evaluation respectively In order to evaluate the reliability, the cost of calculating the amount of supply power and the corresponding supply equipment that cannot be delivered to the land system due to the failure of the internal grid facilities, and the cost calculated through the cost calculation among the selected alternatives The alternative with the minimum sum is selected as the best alternative for the internal grid construction. Includes the optimal alternative selection section.

Description

OPTIMAL ARRANGEMENT SYSTEM FOR INTERNAL GRID OF OFFSHORE WIND FARM}

The present invention relates to an optimal arrangement system for an internal grid of an offshore wind power plant, and more specifically, an optimal configuration alternative for minimizing the overall cost of an offshore wind power plant can be selected through economic and reliability evaluation according to the configuration of the internal grid. It is related to the optimal arrangement system for the internal grid of the offshore wind power generation complex.

Recently, wind power, which has been spotlighted as a new and renewable energy source, is being installed on the sea due to the large capacity and insufficient installation location on land.

However, offshore wind power generation can have a negative impact on the operation of the land power system as well as economic loss when electricity production is interrupted due to geographical access difficulties and failure of grid-connected facilities such as submarine cables.

In general, offshore wind power generation complexes consist of dozens or hundreds of wind turbines, and these wind turbines transmit the power generated in connection with the offshore substation through the internal grid to the land system.

The internal grid, which is composed of dozens of wind turbines and submarine cables, shows a lot of differences in the cost of building offshore wind farms depending on the wind turbine and cable configuration, and if the internal grid submarine cable fails, it is produced by the wind turbine and converted into a marine substation It is very important to review the economics and reliability of the internal grid construction method because the power transmitted is limited.

However, the technology for evaluating the economic feasibility and reliability of offshore wind farms, which has been increasing rapidly, is inadequate. In addition, due to high barriers to entry in related markets, the related information is also insufficient.

The background technology of the present invention is disclosed in Republic of Korea Patent Publication No. 2003-0036935 (published on May 9, 2003, wind farm).

The present invention was created to solve the above problems, and offshore wind power generation to select an optimal configuration alternative for minimizing the overall cost of offshore wind farms through the economic and reliability evaluation according to the composition of the inner grid. The purpose is only to provide an optimal system for placing the inner grid.

In addition, the present invention defines factors to be considered when constructing an internal grid, and inputs elements for constructing an internal grid, and automatically evaluates the economic efficiency and reliability of the offshore wind power generation complex to perform the optimal deployment of the internal grid. The purpose is to provide a grid optimal placement system.

In addition, the present invention evaluates the economic feasibility of the sum of the investment cost for the construction of the internal grid and the power loss cost according to the configuration, and the reliability of the amount of power that cannot be delivered to the offshore substation due to the failure of the submarine cable and the cost of loss (for supply equipment). The purpose is to provide an optimal grid positioning system for offshore wind farms that evaluates

An optimal grid arrangement system for an offshore wind power generation complex according to an aspect of the present invention includes: an expected power calculation unit for estimating expected output of a wind turbine and a wind power generation complex; Alternative selection unit for selecting at least one alternative for the configuration of the internal grid; Economic evaluation unit for evaluating the economics for each of the selected alternatives; A reliability evaluation unit for evaluating the reliability of each of the selected alternatives; In order to evaluate the economics, the total investment cost and the power loss cost are respectively calculated, and for the reliability evaluation, the cost is calculated to calculate the amount of power supplied to the land system that cannot be delivered to the land system due to the failure of the internal grid facilities and the equipment for the supply equipment. ; And among the selected alternatives, an optimal alternative selection unit that selects an alternative in which the sum of costs calculated through the cost calculation is the minimum as an optimal alternative for the construction of an internal grid.

In the present invention, the alternative selection unit, as a consideration factor for constructing the internal grid of the wind farm, 1) the location and spacing of a number of wind turbines, 2) the reference voltage of the inner grid and according to the type or rating of the submarine cable Capacity, 3) Number of feeders, 4) At least one of the inner grid arrangement method is considered.

)으로서, 개별 풍력터빈의 기대출력(

), 풍력발전단지 내의 풍력터빈의 총 개수(

) 및 1년의 총 시간(8760h)의 곱에 의해서 계산되는 것을 특징으로 한다.In the present invention, the expected output of the wind turbine and all the wind farms is the expected annual output of power output (

), The expected output of an individual wind turbine (

), The total number of wind turbines in the wind farm (

) And the total time of one year (8760h).

)은, 케이블 선종별 허용전류(

), 내부그리드(IG)의 기준전압(

) 및 내부그리드 역률(

)의 곱에 근거하여 산정되는 것을 특징으로 한다.In the present invention, the rated capacity of each submarine cable according to the internal grid reference voltage (

), Allowable current per cable type (

), The reference voltage of the internal grid (IG) (

) And inner grid power factor (

It is characterized in that it is calculated based on the product of).

In the present invention, the investment cost for the inner grid is characterized in that it is calculated as the product of the investment cost per unit length (subtraction of material cost and construction cost) per submarine cable type and the distance used.

In the present invention, the total power loss in the inner grid is calculated based on the sum of the power loss in all cable sections.

)은, 케이블에서의 전력손실(

)과 전력 판매단가(

)의 곱에 의거하여 산정되는 것을 특징으로 한다.In the present invention, due to the power loss, the power loss cost, which represents the cost for power that cannot be sold to the land system (

) Is the power loss in the cable (

) And electricity sales price (

It is characterized in that it is calculated based on the product of).

In the present invention, the supply interruption power amount (EEC) is energy that cannot be transferred from a wind turbine to a marine substation due to an internal grid cable failure, and the supply branch equipment (EECC) sells electrical energy equal to the supply interruption power amount. It is a loss cost caused by failure to do so, and the ratio of capacity that cannot be delivered to a marine substation due to a cable failure is characterized by a supply failure ratio (ECCR).

In the present invention, the power supply disturbance (EEC) is characterized in that it is calculated as a product of the annual supply of electricity expected of the offshore wind power generation ratio (ECCR) and offshore wind farms.

)은, 각 피더의 공급지장 비율의 합으로 산정되는 것을 특징으로 한다.In the present invention, the total supply disruption ratio of the inner grid (

) Is characterized in that it is calculated as the sum of the supply obstacle ratio of each feeder.

)은 출력발전단지의 연간 기대 전력 생산량(

)과 내부그리드의 공급지장 비율(

)의 곱에 근거하여 산정되는 것을 특징으로 한다.In the present invention, the power supply disturbance of the internal grid (

) Is the expected annual output of electricity output from the output complex (

) And the rate of supply disruption of the internal grid (

It is characterized in that it is calculated based on the product of).

)은 내부그리드의 공급지장 전력량(

)과 판매단가(

)의 곱에 근거하여 산정되는 것을 특징으로 한다.In the present invention, the supply cost of the internal grid (

) Is the amount of power for the supply of the internal grid (

) And unit price (

It is characterized in that it is calculated based on the product of).

In the present invention, the optimal alternative is characterized in that it is selected as an alternative that minimizes the sum of investment cost, power loss cost, and supply disruption cost.

The present invention allows the selection of the optimal configuration alternative to minimize the overall cost of the offshore wind farm through the evaluation of economic and reliability according to the configuration of the internal grid, so that the investment cost and power loss cost for the internal grid configuration and supply equipment So that the sum can be chosen as the alternative with the least amount. In addition, the present invention can be applied to a large-scale wind farm on land, and to be used to construct an internal grid of a power generation complex composed of various power sources in addition to wind power.

1 is an exemplary view for explaining a typical inner grid arrangement method.
Figure 2 is an exemplary view showing a schematic configuration of the optimal arrangement system for the offshore wind power generation complex according to an embodiment of the present invention.
Figure 3 is a flow chart for explaining the optimal arrangement method of the internal grid in offshore wind power generation complex in FIG.
Figure 4 is an exemplary view showing a graph of the output characteristics of a typical wind turbine.
Figure 5 is an exemplary view shown to explain the definition of the inner grid cable line.
6 is an exemplary view for explaining the operating state model of the submarine cable for application of the present invention.
7 is an exemplary view showing the structure of a ring (Ring) inner grid.
Figure 8 is an exemplary view showing a graph of the output characteristics of the limited wind turbine.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the optimal arrangement system and method for the internal grid offshore wind power generation according to the present invention.

In this process, the thickness of the lines or the size of components shown in the drawings may be exaggerated for clarity and convenience. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to a user's or operator's intention or practice. Therefore, the definition of these terms should be made based on the contents throughout the specification.

In the present invention, the power system reliability evaluation technology is a technology for evaluating the degree of the ability to supply electrical energy to a consumer when an unexpected power facility failure occurs.

In general, the power system performs reliability and stability analysis, evaluates vulnerable facilities, and establishes a new facility construction plan.

At this time, the reliability evaluation results are reflected in economic decision-making factors and decision making for the construction of new facilities. Here, the reliability evaluation technology includes a deterministic method according to the analytical model and a probabilistic method for calculating considering the probability of accidents of facilities, and among them, a probabilistic evaluation method reflecting the characteristics of a complex and unclear power system. A lot of research has been done on.

Consideration elements for constructing an internal grid of an offshore wind power generation complex according to the present invention include the following factors.

1) Location and spacing of multiple wind turbines

2) Reference voltage of the inner grid and the type of submarine cable according to it (rated capacity)

3) Number of feeders

4) How to arrange inner grid

1 is an exemplary view for explaining an arrangement method of a typical inner grid.

Based on the inner grid arrangement, there are a variety of alternatives for constructing the inner grid considering the above factors. For example, typical inner grid arrangement methods include a radial structure, a star structure, and a ring structure.

For optimal placement of the inner grid, it is basically constructed by reflecting economic factors such that the investment cost and the power loss cost of the inner grid are minimized. Here, the algorithm for selecting the optimal alternative is implemented by considering the results through the reliability evaluation technology together.

2 is an exemplary view showing a schematic configuration of an optimal arrangement system for an offshore wind power generation complex according to an embodiment of the present invention.

As shown in FIG. 2, the optimal arrangement system 100 for offshore wind farms according to an embodiment of the present invention includes an expected output calculation unit 110, an alternative selection unit 120, and an economic evaluation unit 130 ), A reliability evaluation unit 140, a cost calculation unit 150 and an optimal alternative selection unit 160.

The expected output calculation unit 110 calculates the expected output of the wind turbine and the wind power generation complex.

The alternative selection unit 120 selects alternatives for constructing an internal grid by reflecting the above-mentioned factors 1) to 4).

The economic evaluation unit 130 evaluates economic feasibility for alternatives for constructing the selected inner grid.

The reliability evaluation unit 140 evaluates the reliability of the alternatives for the selected internal grid configuration.

The cost calculation unit 150 estimates and evaluates the total investment cost and the power loss cost, respectively, for the economic evaluation. In addition, the cost calculation unit 150 calculates the cost of damage caused by failing to sell electric energy equal to the amount of power supplied to the power station because it cannot be transmitted from the wind farm to the offshore substation due to cable failure or the like for the reliability evaluation.

The optimal alternative selection unit 160 selects an alternative in which the sum of the costs calculated through the cost calculation unit 150 is the smallest among the alternatives for constructing the internal grid as the optimal alternative for the internal grid configuration. do.

3 is a flow chart for explaining the optimal arrangement method of the internal grid in the offshore wind farm in FIG. 2.

As shown in Figure 3, first, the expected output of the wind turbine and the wind farm is calculated (S101).

Next, the alternatives for the configuration of the inner grid are selected by reflecting the above considerations (S102).

Next, the economics are evaluated for alternatives for each of the selected internal grid configurations (S103). In order to evaluate the economics for each of the alternatives, the total cost of investment and the cost of loss due to power loss are calculated (S104, S105).

In addition, reliability is evaluated for alternatives for each of the selected internal grid configurations (S106). At this time, in order to evaluate the reliability for each of the alternatives, the amount of power that cannot be transmitted to the land system due to the failure of the internal grid facility and the cost of reliability loss are calculated (S107).

Finally, an alternative in which the sum of each cost is minimal is selected as an optimal alternative for the internal grid construction (S108).

Hereinafter, each configuration means and methods described with reference to FIGS. 2 to 3 will be described in detail.

First, the method of calculating the expected output of the offshore wind farm will be described.

4 is an exemplary view showing a graph of the output characteristics of a typical wind turbine.

The expected output of an offshore wind farm is calculated using the output characteristics of a wind turbine (WT) and the probability distribution of wind speed (WS).

Equation 1 below is a formula showing the output of the wind turbine according to the wind speed.

인 구간은, 풍속이 충분하지 않아서 풍력터빈이 전력을 생산하지 못하는 구간이다. 그리고

구간은, 기동속도(

) 이상에서 풍력터빈이 전력을 생산하기 시작하는 구간으로 풍속이 증가함에 따라 생산되는 전력도 증가한다. 그리고 정격속도(

) 이상의 풍속에서, 풍력터빈은 정격출력(

)을 생산하며, 제한속도(

) 이상의 풍속에서는 풍력터빈을 기계적으로 보호하기 위하여 전력생산을 중단한다.Here, the wind speed

The phosphorus section is a section in which the wind turbine does not produce electricity due to insufficient wind speed. And

The section is the starting speed (

) Above, it is the section where the wind turbine starts to produce power. As the wind speed increases, the power produced also increases. And rated speed (

), At wind speeds above, the wind turbine is rated

), And the speed limit (

) At wind speeds above, power generation is stopped to mechanically protect the wind turbine.

The expected outputs of the individual wind turbines and the entire wind farm are calculated by Equation 2 and Equation 3 below, respectively.

: 개별 풍력터빈의 기대출력,here,

: Expected output of individual wind turbine,

: 풍력발전단지의 연간 기대 전력 생산량,

: Annual expected power production of wind farms,

: 풍력발전단지 내의 풍력터빈의 총 개수,

: The total number of wind turbines in the wind farm,

: 풍속이

일 확률이다.

: Wind speed

It is a probability.

Hereinafter, a method of selecting an alternative for configuring the internal grid will be described.

Alternatives for constructing the inner grid may be selected in consideration of the following consideration factors as described above.

1) Reference voltage of the internal grid and the type of submarine cable according to it (rated capacity)

2) Number of feeders

3) How to arrange the inner grid

First, the rated capacity of the submarine cable according to the internal grid reference voltage is calculated as shown in Equation 4 below.

: 케이블 선종별 정격용량,here,

: Rated capacity by cable type,

: 케이블 선종별 허용전류,

: Allowable current by cable type,

: 내부그리드(IG, Internal Grid)의 기준전압,

: Reference voltage of the internal grid (IG),

: 내부그리드 역률이다.

: Inner grid power factor.

The connection between the wind turbines through the submarine cable is performed according to the following conditions.

1) Wind turbines are linked to nearby wind turbines.

2) Submarine cable lines do not cross each other.

3) The type of submarine cable used is selected so that the total investment cost is minimal within the range that does not exceed the rated capacity, and can be changed for a more economical configuration through comparison with the power loss cost in the future.

Hereinafter, a method for evaluating the internal grid economics will be described.

In order to perform economic and reliability evaluation, each cable line of the inner grid is defined as shown in FIG. 5.

5 is an exemplary view shown to explain the definition of the inner grid cable line.

At this time, each cable line is defined as the following items.

: 케이블 구간 번호,-

: Cable section number,

:

번 케이블 구간을 통해 흐르는 풍력터빈의 누적 개수-

:

Cumulative number of wind turbines flowing through cable section # 1

: 피더 번호-

: Feeder number

First, (1) investment cost calculation method will be described.

The investment cost for the inner grid is the product of the investment cost per unit length per submarine cable type (material cost plus construction cost) and the distance used, calculated by Equation 5 below.

: 전체 투자비용(Total Investment Cost),here,

: Total Investment Cost,

: N번째 피더-

번째 선로구간의 길이,

: Nth feeder

The length of the first track section,

: 케이블 선종별, 단위 길이당 투자비용,

: Cable type, investment cost per unit length,

: 케이블 회선 수

: Number of cable lines

Next, (2) the method for calculating the power stall cost will be described.

The following assumptions are introduced to calculate the internal grid power loss.

1) Failure of the submarine cable is not considered.

2) The voltage in all cable sections is assumed to be the rated voltage.

3) Consider the available state (normal operation state, failure state) of the wind turbine.

Under the above assumption, the power loss for each cable section is calculated by Equation 6 below.

: N번째 피더,

번째 선로구간의 평균 온도에서의 저항,here,

: Nth feeder,

Resistance at the average temperature of the first line section,

: 고장이 발생한 풍력터빈의 개수(

),

: Number of wind turbines that have failed (

),

: 풍력터빈의 가용률,

: Availability of wind turbines,

: 풍력터빈의 비가용률(

),

: Non-availability rate of wind turbine (

),

: N번째 피더의

번째 선로구간에 흐를 수 있는 최대 유효전력, 또는

번째 선로구간을 기준으로 피더의 끝단까지의 풍력터빈의 누적용량,

: Nth feeder

Maximum active power that can flow in the second track section, or

The accumulated capacity of the wind turbine to the end of the feeder based on the first track section,

: 케이블 정격전압,

: Rated voltage of cable,

: 역률,

: Power factor,

: Loss load factor,

: Loss load factor,

: 1년의 총 시간(T = 8760h)이다.

: Total time of one year (T = 8760h).

Then, the total power loss of the inner grid is calculated as shown in Equation 7 below as the sum of the power loss of all cable sections.

In addition, the power loss cost, which represents the cost for power that cannot be sold by land system due to power loss, is calculated by Equation 8 below.

: 케이블에서의 전력손실(Cable Loss),here,

: Cable Loss in Cable,

: 케이블에서의 전력손실비용(Cost of Cable Loss),

: Cost of Cable Loss,

: 전력 판매단가이다.

: This is the electricity sales price.

Hereinafter, a method for evaluating internal grid reliability will be described.

First, (1) the amount of power at the supply site and the equipment for the supply site will be described.

First, as a result of evaluating the reliability of the internal grid, the power supply interruption power and the index for supply equipment are defined as follows.

1) Expected Energy Curtailed (EEC)

: Energy that cannot be transferred from the wind turbine to the offshore substation due to the failure of the internal grid cable.

2) Supply paper equipment (EECC, EEC Cost)

: Cost of damage caused by failing to sell the electric energy equal to the amount of power supplied to the supply.

To calculate this, the index below is additionally defined.

3) Expected Capacity Curtailed Rate (ECCR)

: Ratio of capacity (power) that cannot be delivered to a marine substation due to a cable failure.

The supply interruption power amount (EEC) is calculated by multiplying the supply interruption ratio (ECCR) and the expected annual power generation of the offshore wind farm.

Next (2) The operation model of the cable will be described.

In order to consider the failure of the submarine cable, which is an internal grid component, the operating state of the cable is defined as a two-state model.

As shown in FIG. 6, the movement to each state is represented using two transition rates defined in the reliability analysis.

6 is an exemplary view for explaining the operating state model of the submarine cable for application of the present invention.

In the two-state model, the cable availability (A, Availability) and unavailability (U, Unavailability) are calculated as in Equation 9 below.

: 해저케이블의 단위 길이당 평균 고장률,here,

: Average failure rate per unit length of submarine cable,

: 평균 수리시간이다.

: Average repair time.

Hereinafter, an exemplary method for evaluating the reliability of the inner grid of the radial and star structures will be described.

번째 선로에 고장이 발생한 경우,

번째 선로에 흐를 수 있는 최대 유효전력을 공급지장전력으로 산정한다. 이에 N번째 피더의

번째 선로에 대한 공급지장 비율은 아래의 수학식 10으로 산정한다.In the inner grid of radial or star structure, the Nth feeder

If a fault occurs on the first line,

The maximum effective power that can flow in the second line is calculated as the supply interruption power. Therefore, the Nth feeder

The ratio of supply disruption to the second track is calculated by Equation 10 below.

here,

: N 번째 피더,

번째 선로구간에 흐를 수 있는 최대 유효전력,

: Nth feeder,

Maximum active power that can flow in the second track section,

: 풍력단지의 전체 용량이다.

: Total capacity of the wind farm.

In addition, the total supply obstacle ratio of the inner grid is calculated as the sum of the supply obstacle ratio of each feeder as shown in Equation 11 below.

In addition, the power supply interruption power (EEC) and the supply interruption cost (EECC) of the internal grid are calculated by Equations 12 and 13 below, respectively.

Hereinafter, by way of example, the inner grid of the cyclic structure will be described.

7 is an exemplary view showing a structure of a ring inner ring.

The characteristics of the inner grid of the cyclic structure are as follows.

1) The annular structure is constructed in a radial structure by connecting the ends of each feeder with a spare cable.

2) In the normal operating state, the spare cable is kept open, and when a failure occurs in a certain cable section in the feeder, it is closed.

3) In the annular structure, all cables constituting each feeder use the same wire type.

)로 나뉜다. In the inner grid of the annular structure of the above characteristics, any Nth feeder has two lower feeders (

).

Assuming that a cable failure has occurred at one of the two lower feeders, the power flowing through the cable flows through the feeder that has not failed through the spare cable. In this situation, the supply interruption power may or may not occur depending on the rated capacity of the feeder that has not failed.

선로구간에서 고장이 발생한 경우,

선로구간으로 흐르던 전력은

하위 피더를 통해서 흐르게 된다.For example, as shown in Figure 7,

If a failure occurs in the track section,

The electric power that flowed into the track section

It flows through the lower feeder.

In this case, the following two situations may occur.

하위 피더의 케이블 용량이, (1)~(4)번 풍력터빈 용량의 합보다 크다면, 공급지장전력은 발생하지 않는다.1) If,

If the cable capacity of the lower feeder is greater than the sum of the capacities of the wind turbines (1) to (4), supply disturbance power does not occur.

하위 피더의 케이블 용량이, (1)~(4)번 풍력터빈 용량의 합보다 작다면, 케이블 용량을 초과하는 풍력터빈의 출력량만큼의 공급지장전력이 발생하게 된다.2) But if,

If the cable capacity of the lower feeder is smaller than the sum of the capacities of wind turbines (1) to (4), supply interruption power is generated as much as the output amount of the wind turbine exceeding the cable capacity.

하위 피더에 연계된 풍력터빈들은, 케이블 용량에 의하여 그 출력이 제한된다. For the second situation (that is, the situation in which the supply interruption power occurs), the supply interruption power is calculated as shown in Equation 14 below. At this time

In the case of wind turbines connected to the lower feeder, the output is limited by the cable capacity.

8 is an exemplary view showing a graph of output characteristics of a limited wind turbine.

The rated output of the wind turbine in the above two situations is as shown in Equation 14 below.

:

케이블에서 고장이 발생한 경우의 풍력터빈의 정격출력,here,

:

Rated output of wind turbine in case of cable failure,

: N번째 피더를 구성하는 하위 피더. 각각 고장이 발생한 하위 피더와 고장이 발생하지 않은 하위 피더를 나타냄.

: Lower feeder constituting the Nth feeder. Each of the lower feeders that have failed and the lower feeders that have not failed.

: 하위 피더의 케이블 정격용량,

: Subordinate feeder's rated cable capacity,

: 고장이 발생하지 않은 하위 피더에 연계된 전체 풍력터빈의 개수이다.

: Total number of wind turbines connected to the lower feeder that has not failed.

In consideration of the above two situations, the ratio of the supply obstacle to the inner grid of the annular structure can be calculated using Equation 15 below.

In the inner grid of the annular structure, the supply interruption power amount and the supply interruption cost are calculated using Equation 11, Equation 12, and Equation 13, which are the same formulas as the inner grid of the radial and star structures.

Hereinafter, a method of selecting an optimal internal grid configuration alternative will be described.

The optimal alternative is selected as an alternative in which the sum of investment cost, power loss cost, and supply disruption cost is minimal.

Here, the power loss cost and the supply disruption cost, which represent the annual cost, are evaluated and reflected as the net present value for the considered life span.

The objective function for this is as shown in Equation 16 below.

: 연도,

의 최대값은 평가기간이 되는 설비 수명기간을 의미하고,

: 할인율을 의미한다.here,

: year,

The maximum value of means the life span of the equipment that becomes the evaluation period,

: Means discount rate.

As described above, the optimal arrangement system of the offshore wind power generation complex according to the present invention improves operational efficiency in accordance with the design and construction of a large-scale offshore wind power generation complex, minimizes damage due to electrical failures and power outages, and produces stable power. It has the effect of improving operational stability. In addition, when applying the method according to the present invention when designing a large-scale offshore wind power generation complex, it is possible to expect a cost reduction effect through design of an optimal internal network in consideration of economic efficiency and reliability.

The present invention has been described above with reference to the embodiment shown in the drawings, but this is only exemplary, and those skilled in the art to which the art pertains may have various modifications and other equivalent embodiments. You will understand the point. Therefore, the technical protection scope of the present invention should be defined by the following claims.

110: Expected output calculation unit 120: Alternative selection unit
130: economic evaluation unit 140: reliability evaluation unit
150: Cost calculation 160: Optimal alternative selection department

Claims (13)

Expected output calculation unit for estimating expected output of wind turbines and wind farms;
Alternative selection unit for selecting at least one alternative for the configuration of the internal grid;
Economic evaluation unit for evaluating the economics for each of the selected alternatives;
A reliability evaluation unit for evaluating the reliability of each of the selected alternatives;
In order to evaluate the economics, the total investment cost and the power loss cost are respectively calculated, and for the reliability evaluation, the cost is calculated to calculate the supply power amount that cannot be delivered to the land system due to the failure of the internal grid facility and the supply equipment. ; And
Includes; among the selected alternatives, an optimal alternative selection unit that selects, as an optimal alternative for constructing an internal grid, an alternative in which the sum of costs calculated through the cost calculation is the minimum.
The total power loss in the internal grid is calculated based on the sum of the power loss in all cable sections.
The method of claim 1, wherein the alternative selection unit,
As a consideration factor for constructing the internal grid of the wind power generation complex,
1) Location and spacing of multiple wind turbines,
2) The reference voltage of the internal grid and the type or rated capacity of the submarine cable,
3) Number of feeders,
4) Optimal placement system for offshore wind farms, characterized by considering at least one of the inner grid placement methods.
According to claim 1,
Expected output of the wind turbine and all wind farms is the expected annual output of electricity produced by the output farms (

), The expected output of an individual wind turbine (

), The total number of wind turbines in the wind farm (

) And the total time of year (8760h) is calculated by the product of the offshore wind farm complex internal grid optimal placement system.
According to claim 2,
Rated capacity of each submarine cable according to the internal grid reference voltage (

), Allowable current per cable type (

), The reference voltage of the internal grid (IG) (

) And inner grid power factor (

) Is an optimal grid positioning system for offshore wind farms.
According to claim 1,
The investment cost for the inner grid is calculated by multiplying the investment cost per unit length (sub-material cost and construction cost) by the submarine cable type and the distance used, and the optimal arrangement system for an offshore wind farm complex.
delete According to claim 1,
Power loss cost, which represents the cost for power that cannot be sold by land system due to power loss (

) Is the power loss in the cable (

) And electricity sales price (

) Is the optimal placement system of the offshore wind farm complex.
According to claim 1,
The power supply disturbance (EEC) is energy that cannot be transferred from the wind turbine to the offshore substation due to an internal grid cable failure,
The supply site equipment (EECC) is a loss cost caused by not selling the electric energy equal to the amount of power supplied to the supply site,
Optimal placement system for offshore wind farms, characterized in that the ratio of the capacity that cannot be delivered to the offshore substation due to cable failure is the supply disturbance ratio (ECCR).
The method of claim 8, wherein the power supply disturbance (EEC) is,
Optimal arrangement system for an offshore wind farm complex, characterized in that it is calculated by multiplying the supply obstacle ratio (ECCR) and the expected annual power generation of the wind farm.
The method of claim 8,
Percentage of total supply disruption of the internal grid (

) Is the optimum arrangement system for the internal grid of offshore wind farms, characterized in that it is calculated as the sum of the supply obstacle ratio of each feeder.
The method of claim 8,
The supply power of the internal grid (

) Is the expected annual output of electricity output from the output complex (

) And the rate of supply disruption of the internal grid (

) Is an optimal grid positioning system for offshore wind farms.
The method of claim 8,
Cost of disruption of supply of internal grid (

) Is the amount of power for the supply of the internal grid (

) And unit price (

) Is an optimal grid positioning system for offshore wind farms.
The method of claim 1, wherein the optimal alternative is,
Optimal layout system for offshore wind farm complexes, characterized in that the sum of investment cost, power loss cost, and supply disruption cost is selected as an alternative.

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