Method for estimating heat loss of conductor in new energy project and method for selecting cross section of conductor

Abstract

The present application belongs to the field of electric power engineering, and particularly relates to a new energy engineering conductor heat loss estimation method and a conductor cross section selection method, comprising obtaining power generation information of an existing new energy power station, and obtaining initial expected power of a newly built new energy power station through new energy power station output simulation simulation; according to the power generation information and the initial expected power, obtaining conductor heat loss information of the newly built new energy power station during operation under a plurality of conductor cross-sectional areas, to complete the estimation of the conductor annual average heat loss power of the newly built new energy power station during operation under a plurality of conductor cross-sectional areas; the technical problem that the existing power station conductor heat loss estimation method does not consider the actual output characteristics of the new energy project, it is difficult to accurately estimate the conductor heat loss of the new energy project, and it is difficult to accurately obtain the economic cross section of the new energy project.

Description

Technical Field

[0001] This invention belongs to the field of power engineering, specifically relating to a method for estimating conductor heat loss and a method for selecting conductor cross-section in new energy engineering. Background Technology

[0002] In the field of power line engineering, the cross-sectional area of ​​the conductor affects the construction investment cost, power heat loss cost, and fault repair cost of the line. In order to save construction investment costs, the conductor cross-sectional area is required to be designed to be relatively small. In order to reduce power heat loss cost and fault repair cost, the conductor cross-sectional area is required to be designed to be relatively large. During the life cycle of the conductor, the above cost factors are comprehensively considered to determine a more reasonable conductor cross-sectional area, that is, the economic cross-sectional area of ​​the conductor.

[0003] Currently, my country's power industry mainly calculates the economic cross-sectional area of ​​conductors by using the economic current density value set by the national competent authority. Although this method is simple to operate, it does not take into account the actual output characteristics of the power source. The actual output characteristics of the power source mainly affect the estimation of the heat loss cost of the conductor (specifically, it affects the estimation of the average annual heat loss power of the conductor). Therefore, this calculation method usually cannot accurately reflect the heat loss cost of the conductor, and thus it is difficult to accurately obtain the economic cross-section of the power supply conductor.

[0004] To address the aforementioned issues, existing methods for estimating conductor heat loss in power plants often involve acquiring operational data from similar existing power plants to forecast the output of newly constructed power plants. Based on this forecast, the average annual heat loss power of the conductors under different conductor cross-sectional areas is calculated, leading to the calculation of the conductor's energy heat loss cost. However, this method is designed for traditional power plants, which have the following characteristics: 1) Stable load, with load fluctuations through conductors within a certain range during operation, and a tendency to increase year by year with industrial development; 2) High annual utilization hours, with long operating times throughout the year, typically 5000 hours or more, and relatively small differences in operating hours between similar traditional power plants. These characteristics result in similar actual output characteristics among similar traditional power plants, making existing operational data from similar traditional power plants an excellent reference for forecasting the output of newly constructed traditional power plants.

[0005] However, the operating scenarios of new energy power plants have the following characteristics that differ from those of traditional power plants: 1) Large load fluctuations. For example, during the operation of photovoltaic power plants, the ideal power generation during the day follows a parabola, with the maximum load occurring at noon in summer, lasting for about 2 to 3 hours. After evening, there is no more power output. Photovoltaic power output is greatly affected by solar radiation, and clouds and fog in the air will reduce photovoltaic power generation, bringing great uncertainty to power output. Moreover, power generation is seasonal. In summer, photovoltaic power can reach the rated output power, while in spring, autumn, and winter, the output power is lower than the rated power. Wind power output is affected by wind strength, and power fluctuations are also uncertain. 2) The annual utilization hours are relatively small, far less than the line operation hours of traditional power plants. The peak power operation hours are only a few hundred hours (around 300-1000 hours), and there are large differences in the peak power operation hours between similar new energy power plants. These characteristics make the actual output characteristics of similar new energy power plants vary greatly, and the existing operating data of similar new energy power plants are not very useful for the output prediction of newly built new energy power plants.

[0006] In summary, existing methods for estimating the heat loss of power plant conductors fail to take into account the actual power output characteristics of new energy projects, making it difficult to accurately estimate the average annual heat loss power of the conductors in new energy projects. Summary of the Invention

[0007] This invention provides a method for estimating conductor heat loss and selecting conductor cross-section in new energy projects. This solves the technical problem that existing methods for estimating conductor heat loss in power plants do not take into account the actual output characteristics of new energy projects, making it difficult to accurately estimate the conductor heat loss and thus difficult to accurately obtain the economic cross-section of the conductor in new energy projects.

[0008] The technical solution adopted in this invention is: a method for estimating conductor heat loss in new energy engineering, comprising the following steps:

[0009] Step 1: Obtain the power generation information of existing new energy power plants, and obtain the initial expected power of the new energy power plant through power output simulation.

[0010] Step 2: Based on the power generation information and the initial expected power, obtain the conductor heat loss information under various conductor cross-sectional areas during the operation of the newly built new energy power station, so as to complete the estimation of the annual average conductor heat loss power under various conductor cross-sectional areas during the operation of the newly built new energy power station.

[0011] The above technical solution obtains the initial expected power of the newly built new energy power station through power output simulation to estimate the initial power output of the new power station. Then, it integrates the power generation information of existing new energy power stations to estimate the expected power of the new power station each year during its operation. Based on the expected power of the new power station each year, it obtains conductor heat loss information under various conductor cross-sectional areas during the operation of the new power station, thereby estimating the annual average conductor heat loss power under various conductor cross-sectional areas during the operation of the new power station. This makes the conductor heat loss estimation method for new energy projects provided by this invention more consistent with the actual power output characteristics of new energy projects, compared to existing methods that often rely on obtaining operating data from similar existing power stations to estimate the output of the new power station and then calculating the annual average conductor heat loss power under different conductor cross-sectional areas. This solves the technical problem that existing methods for estimating conductor heat loss fail to consider the actual power output characteristics of new energy projects, making it difficult to accurately estimate conductor heat loss and thus difficult to accurately obtain the economic cross-section of the conductors in new energy projects.

[0012] Furthermore, step 2 includes:

[0013] S1: Based on the power generation information and the initial expected power, obtain the expected power of the newly built new energy power station for each year during its operation;

[0014] S2: Based on the expected power of the newly built new energy power station in each year during its operation, obtain the average calculated current of the newly built new energy power station in each year during its operation.

[0015] S3: Based on the average calculated current of the newly built new energy power station in each year during its operation, obtain the conductor heat loss information of the newly built new energy power station under various conductor cross-sectional areas during its operation.

[0016] Furthermore, the method for calculating the initial expected power includes:

[0017]

[0018] and

[0019] Q g The g-th output power that appears in the simulation results of the power output of the new energy power plant; β g The output power Q of the g-th type in the simulation results of the power output of the new energy power plant g The probability of occurrence; y is the number of different output powers in the simulation results of the new energy power plant output; Q′ is the initial expected power.

[0020] Furthermore, the method for calculating the initial expected power includes:

[0021]

[0022] and

[0023]

[0024] Q g The g-th output power that appears in the simulation results of the power output of the new energy power plant; β g The output power Q of the g-th type in the simulation results of the power output of the new energy power plant g The probability of occurrence; a g To correspond to the g-th type of output power Q g The assigned weighting coefficient; y is the number of different output powers in the simulation results of the new energy power plant output; Q′ is the initial expected power.

[0025] The above two technical solutions propose two methods for calculating the initial expected power Q′. In the first method, the initial expected power Q′ is derived from the g-th output power Q that appears in the simulation results of the new energy power plant output. g The output power Q of the g-th type in the simulation results of the new energy power plant output g The probability of occurrence β g It is obtained by direct calculation; the calculation is convenient and simple, but the initial expected power Q′ obtained by this method fails to take into account some objective factors that cannot be taken into account in the simulation of the output of new energy power plants.

[0026] In the latter calculation method, the corresponding g-th output power Q is added to the calculation of the initial desired power Q′. g The assigned weight coefficient a g This method allows for the artificial adjustment of the initial expected power Q′, enabling the calculation of the initial expected power Q′ to take into account some objective factors that cannot be considered in the simulation of the output of new energy power plants (such as: when the power generation in the simulation of the output of new energy power plants is higher than the grid load, resulting in the problem of wind and solar curtailment, the excess power generation will become ineffective power, etc.). This makes the initial expected power Q′ calculated by this method more complex than the previous calculation method, but the calculation result is more accurate.

[0027] Furthermore, the power generation information includes the unit-scale power generation of the existing new energy power plants in each year within the statistical period;

[0028] In step S1, based on the power generation information, the average output power change rate of the existing new energy power plant in two consecutive years within the statistical period is obtained; then, based on the initial expected power and the average output power change rate, the expected power of the newly built new energy power plant in each year during its operation is obtained.

[0029] Furthermore, the method for calculating the average output power change rate includes:

[0030]

[0031] Among them W z c represents the unit-scale power generation of the existing new energy power plant in the z-th year within the statistical period; z represents the statistical period of the existing new energy power plant; and V represents the average output power change rate.

[0032] By obtaining the unit-scale power generation of the existing new energy power plant in each year within the statistical period; obtaining the change in unit-scale power generation of the existing new energy power plant between two adjacent years within the statistical period; and then obtaining the average change in unit-scale power generation of the existing new energy power plant between two adjacent years within the statistical period, and using the average output power change rate of the existing new energy power plant between two adjacent years within the statistical period as the expected average output power change rate of the newly built new energy power plant during its operation, the expected power of the newly built new energy power plant in each year during its operation can be calculated.

[0033] While the output of existing renewable energy power plants (e.g., power generation per unit area, actual output power) is not very relevant for estimating the output of newly built renewable energy power plants, the average output power change rate of renewable energy power plants over two consecutive years is usually mainly affected by changes in weather resources in the location of the renewable energy power plant. Therefore, the average output power change rate of existing renewable energy power plants with similar weather resources (e.g., similar geographical location, similar geographical conditions) over two consecutive years is a more relevant reference for the average output power change rate of newly built renewable energy power plants over two consecutive years.

[0034] Furthermore, the method for calculating the expected power output of the newly built new energy power plant each year during its operation includes:

[0035] Q t =Q′+Q′V t

[0036] Where t is the year the newly built new energy power station is put into operation; Q′ is the initial expected power; Q tLet V be the expected power output of the newly built new energy power plant in year t during its operation; V is the average output power change rate.

[0037] Furthermore, the calculation method for the average annual calculated current of the newly built new energy power plant during its operation includes:

[0038]

[0039] Where U is the nominal line voltage of the conductor during operation; t is the year the newly built new energy power station has been in operation; Q t Let I be the expected power output of the newly built new energy power plant in year t during its operation; t Let t be the average calculated current of the newly built new energy power plant during its operation in year t.

[0040] Furthermore, in S3, the conductor heat loss information includes the average annual heat loss power of the conductors for each year under various conductor cross-sectional areas during the operation of the newly built new energy power plant; the calculation method for the average annual heat loss power of the conductors in year t under various conductor cross-sectional areas during the operation of the newly built new energy power plant includes:

[0041]

[0042] Where P t I represents the average annual heat loss power of the conductors in year t under various conductor cross-sectional areas during the operation of the newly built new energy power plant; t ρ is the average calculated current in year t during the operation of the newly built new energy power station; t is the year the newly built new energy power station is in operation; ρ is the resistivity of the conductor; L is the total length of the line of the newly built new energy power station; A is the cross-sectional area of ​​the conductor.

[0043] This invention also provides a method for selecting conductor cross-sections in new energy projects, implemented using the conductor heat loss estimation method for new energy projects according to this invention, comprising the following steps:

[0044] S1: Obtain conductor heat loss information under various conductor cross-sectional areas during the operation of the newly built new energy power station;

[0045] S2: Based on the conductor heat loss information, obtain conductor heat loss cost information, which includes conductor heat loss cost under various conductor cross-sectional areas during the operation of the newly built new energy power station.

[0046] S3: Based on the conductor heat loss cost information and the conductor construction and maintenance costs of the new energy power station under various conductor cross-sectional areas, obtain the total conductor cost information, which includes the total conductor cost of the new energy power station under various conductor cross-sectional areas within its maximum operating life.

[0047] S4: Based on the total cost information of the conductor, select the economically optimal conductor cross-sectional area to complete the conductor cross-section selection for the new energy project. Attached Figure Description

[0048] Figure 1 This is a flowchart illustrating the method for selecting the conductor cross-sectional area in a new energy line project, as shown in the embodiment. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings:

[0050] Example 1:

[0051] like Figure 1 As shown, this embodiment 1 provides a method for estimating conductor heat loss and selecting conductor cross-section for new energy projects. It solves the technical problem that existing methods for estimating conductor heat loss in power plants do not take into account the actual output characteristics of new energy projects, making it difficult to accurately estimate the conductor heat loss of new energy projects, and thus making it difficult to accurately obtain the economic cross-section of conductors for new energy projects.

[0052] The technical solution adopted in this invention is: a method for estimating conductor heat loss in new energy engineering, comprising the following steps:

[0053] Step 1: Obtain the power generation information of existing new energy power plants, and obtain the initial expected power of the new energy power plant through power output simulation.

[0054] Step 2: Based on the power generation information and the initial expected power, obtain the conductor heat loss information under various conductor cross-sectional areas during the operation of the newly built new energy power plant, so as to complete the estimation of the annual average conductor heat loss power under various conductor cross-sectional areas during the operation of the newly built new energy power plant.

[0055] The above technical solution obtains the initial expected power of the newly built new energy power station through power output simulation to predict its initial output. Then, it integrates the power generation information of existing new energy power stations to predict the expected power for each year during the operation of the new power station. Based on the expected power for each year during the operation of the new power station, it obtains conductor heat loss information under various conductor cross-sectional areas during the operation of the new power station, thereby estimating the annual average conductor heat loss power under various conductor cross-sectional areas. This method for estimating conductor heat loss in new energy projects, compared to existing methods that often rely on obtaining operating data from similar existing power stations to predict the output of the new power station and then calculating the annual average conductor heat loss power under different conductor cross-sectional areas, is more consistent with the actual output characteristics of new energy projects. It solves the technical problem that existing methods for estimating conductor heat loss fail to consider the actual output characteristics of new energy projects, making it difficult to accurately estimate conductor heat loss and thus difficult to accurately determine the economic cross-section of the conductors.

[0056] Step 2 includes the following sub-steps:

[0057] S1: Based on the power generation information and the initial expected power, obtain the expected power of the newly built new energy power plant for each year during its operation;

[0058] S2: Based on the expected power of the newly built new energy power plant in each year during its operation, obtain the average calculated current of the newly built new energy power plant in each year during its operation.

[0059] S3: Based on the average calculated current of the newly built new energy power plant each year during its operation, obtain the conductor heat loss information of the newly built new energy power plant under various conductor cross-sectional areas during its operation.

[0060] There are multiple algorithms for calculating the initial expected power, including but not limited to the following:

[0061] Option 1: The calculation methods for the initial expected power include:

[0062]

[0063] and

[0064] Q g The g-th output power that appears in the simulation results of the power output of the new energy power plant; β g The output power Q of the g-th type in the simulation results of the power output of the new energy power plant gThe probability of occurrence; y is the number of different output powers in the simulation results of the new energy power plant output; Q′ is the initial expected power.

[0065] Option 2, the calculation method for the initial expected power includes:

[0066]

[0067] and

[0068]

[0069] Q g The g-th output power that appears in the simulation results of the power output of the new energy power plant; β g The output power Q of the g-th type in the simulation results of the power output of the new energy power plant g The probability of occurrence; a g To correspond to the g-th type of output power Q g The assigned weighting coefficient; y represents the number of different output powers in the simulation results of the new energy power plant output; Q′ represents the initial expected power.

[0070] In the two schemes mentioned above, two methods for calculating the initial expected power Q′ are proposed. In Scheme 1, the initial expected power Q′ is derived from the g-th output power Q that appears in the simulation results of the new energy power plant output. g The output power Q of the g-th type in the simulation results of the new energy power plant output g The probability of occurrence β g It is obtained by direct calculation; the calculation is convenient and simple, but the initial expected power Q′ obtained by this method fails to take into account some objective factors that cannot be taken into account in the simulation of the output of new energy power plants.

[0071] In Scheme 2, the corresponding g-th type of output power Q is added to the calculation of the initial desired power Q′. g The assigned weight coefficient a g This method allows for the artificial adjustment of the initial expected power Q′, enabling the calculation of the initial expected power Q′ to take into account some objective factors that cannot be considered in the simulation of the output of new energy power plants (such as: when the power generation in the simulation of the output of new energy power plants is higher than the grid load, resulting in the problem of wind and solar curtailment, the excess power generation will become ineffective power, etc.). This makes the initial expected power Q′ calculated by this method more complex than the previous calculation method, but the calculation results are more accurate.

[0072] Among them, the power generation information includes the unit-scale power generation of existing new energy power plants in each year within the statistical period;

[0073] In step S1, based on the power generation information, the average output power change rate of existing new energy power plants in adjacent two years within the statistical period is obtained; then, based on the initial expected power and the average output power change rate, the expected power of the newly built new energy power plant in each year during its operation is obtained.

[0074] The calculation methods for the average output power change rate include:

[0075]

[0076] Among them W z denoted as , where is the unit-scale power generation of existing new energy power plants in year z within the statistical period; is , where c is the statistical period for existing new energy power plants; is , where z is the statistical year for existing new energy power plants; and is , where V is the average output power change rate.

[0077] By obtaining the unit-scale power generation of existing new energy power plants in each year within the statistical period; obtaining the change in unit-scale power generation of existing new energy power plants between two adjacent years within the statistical period; and then obtaining the average change in unit-scale power generation of existing new energy power plants between two adjacent years within the statistical period, and using the average output power change rate of existing new energy power plants between two adjacent years within the statistical period as the expected average output power change rate of newly built new energy power plants during the operation period, the expected power of newly built new energy power plants in each year during the operation period can be calculated.

[0078] While the output of existing renewable energy power plants (e.g., power generation per unit area, actual output power) is not very useful for estimating the output of newly built renewable energy power plants, the average output power change rate of renewable energy power plants over two consecutive years during their operation is usually mainly affected by changes in weather resources in the location of the renewable energy power plant. Therefore, the average output power change rate of existing renewable energy power plants with similar weather resources (e.g., similar geographical location, similar geographical conditions) over two consecutive years during their operation is a more reliable reference for the average output power change rate of newly built renewable energy power plants over two consecutive years during their operation.

[0079] The calculation method for the expected power output of newly built new energy power plants each year during their operation includes:

[0080] Q t =Q′+Q′V t

[0081] Where t represents the year the newly built new energy power plant is put into operation; Q′ represents the initial expected power; Q t Let V be the expected power output of the newly built new energy power plant in year t during its operation; V is the average output power change rate.

[0082] That is to say

[0083] The calculation method for the average annual current of a newly built new energy power plant during its operation includes:

[0084]

[0085] Where U is the nominal line voltage of the conductor during operation; t is the year the newly built new energy power station has been in operation; Q t Let I be the expected power output of the newly built new energy power plant in year t during its operation. t This represents the average calculated current of a newly built new energy power plant in year t during its operation.

[0086] In S3, the conductor heat loss information includes the average annual heat loss power of the conductors for each year under various conductor cross-sectional areas during the operation of the newly built new energy power plant; the calculation method for the average annual heat loss power of the conductors in year t under various conductor cross-sectional areas during the operation of the newly built new energy power plant includes:

[0087]

[0088] Where P t I represents the average annual heat loss power of the conductors in year t under various conductor cross-sectional areas during the operation of a newly built new energy power plant; t ρ is the average calculated current in year t during the operation of the newly built new energy power station; t is the year the new energy power station is in operation; ρ is the resistivity of the conductor; L is the total length of the line of the new energy power station; A is the cross-sectional area of ​​the conductor.

[0089] Example 2:

[0090] Based on the conductor heat loss estimation method for new energy projects provided in Example 1, Example 2 provides a conductor cross-section selection method for new energy projects, including the following steps:

[0091] S1: Obtain conductor heat loss information under various conductor cross-sectional areas during the operation of newly built new energy power plants;

[0092] S2: Based on the conductor heat loss information, obtain the conductor heat loss cost information, which includes the conductor heat loss cost under various conductor cross-sectional areas during the operation of newly built new energy power plants.

[0093] S3: Based on conductor heat loss cost information and conductor construction and maintenance costs for new energy power plants under various conductor cross-sectional areas; obtain total conductor cost information, which includes the total conductor cost for new energy power plants under various conductor cross-sectional areas within the maximum operating life of various conductor cross-sectional areas.

[0094] S4: Based on the total cost information of the conductor, select the economically optimal conductor cross-sectional area to complete the conductor cross-section selection for the new energy project.

[0095] Among them, the construction and maintenance costs of conductors for newly built new energy power plants under various conductor cross-sectional areas include conductor construction costs and conductor maintenance costs;

[0096] In other words, the total cost of conductors under various conductor cross-sectional areas within the maximum operating life of a newly built new energy power plant includes the conductor heat loss cost, conductor maintenance cost, and conductor construction cost under various conductor cross-sectional areas during the operation of the newly built new energy power plant; the calculation method for the total cost of conductors under various conductor cross-sectional areas within the maximum operating life of a newly built new energy power plant includes:

[0097] S = K + F + H

[0098] Where K represents the conductor construction cost of the new energy power plant under various conductor cross-sectional areas; F represents the conductor heat loss cost under various conductor cross-sectional areas during the operation of the new energy power plant; and H represents the conductor maintenance cost under various conductor cross-sectional areas during the operation of the new energy power plant.

[0099] The calculation methods for conductor construction costs under various conductor cross-sectional areas in the line engineering of newly built new energy power stations include:

[0100] K = (Ks + Kr)L

[0101] Where Ks is the cost per unit length of the line that is not related to the conductor cross-sectional area; Kr is the cost per unit length of the line that is related to the conductor cross-sectional area; and L is the total length of the line for the newly built new energy power station.

[0102] Costs related to conductor cross-sectional area in the unit length investment of a power line include transportation costs, material costs, and labor costs for the conductor and related equipment; costs unrelated to conductor cross-sectional area in the unit length investment of a power line include various management costs in the unit length investment of a power line.

[0103] The calculation methods for costs per unit length of the line that are unrelated to the conductor cross-sectional area include:

[0104]

[0105] Where Ni is the i-th management cost per unit length of the line investment that is unrelated to the conductor cross-sectional area; M k is the cost of the kth equipment / facility in the unit length investment of the line that is unrelated to the conductor cross-sectional area; m is the number of management costs in the unit length investment of the line that are unrelated to the conductor cross-sectional area; n is the number of equipment / facilities in the unit length investment of the line that are unrelated to the conductor cross-sectional area.

[0106] The calculation methods for costs related to conductor cross-sectional area in the unit length investment of the railway line include:

[0107]

[0108] Where A is the cross-sectional area of ​​the conductor; H f is the f-th cost coefficient related to conductor cross-sectional area in the unit length investment of the line; x is the number of cost coefficients related to conductor cross-sectional area in the unit length investment of the line.

[0109] That is to say

[0110] The calculation methods for conductor heat loss costs under various conductor cross-sectional areas during the operation of newly built new energy power plants include:

[0111]

[0112] Where b is the maximum operating life of the newly built new energy power station; ρ is the resistivity of the conductor; L is the total length of the line of the newly built new energy power station; A is the cross-sectional area of ​​the conductor; E is the calculated electricity price of the newly built new energy power station (unit: yuan / kWh); P t δ represents the average annual heat loss power of the conductors in year t under various conductor cross-sectional areas during the operation of a newly built new energy power plant. t This represents the number of operating hours in year t during the operation of the newly built new energy power plant.

[0113] That is to say

[0114] Among them, the number of operating hours in year t during the operation of newly built new energy power plants δ t The annual operating hours of the new energy power plant are used to determine the initial expected power output when the power output of the new energy power plant is obtained through simulation.

[0115] The calculation methods for conductor maintenance costs under various conductor cross-sectional areas during the operation of newly built new energy power plants include:

[0116]

[0117] Hd t Hg represents the total maintenance cost of the conductor in year t during the operation of the newly built new energy power plant; t Let be the total cost of fault repair for the conductor in year t during the operation of the newly built new energy power station; t is the year the new energy power station is in operation; b is the maximum operating life of the new energy power station; H is the conductor maintenance cost of the new energy power station under various conductor cross-sectional areas.

[0118] Based on the existing conductor maintenance cost information of new energy power plants (that is, the annual conductor maintenance cost details for different existing new energy power plants under various conductor cross-sectional areas), it can be seen that the total annual maintenance cost of conductors during the operation of newly built new energy power plants is unrelated to the conductor cross-sectional area, while the total annual fault repair cost of conductors during the operation of newly built new energy power plants is related to the conductor cross-sectional area.

[0119] The calculation method for the total cost of fault repair in year t during the operation of a newly built new energy power station includes:

[0120] Hg t =γHg′ t +Hgd t

[0121] Among them Hg' t The cost of repairing a single conductor fault in year t during the operation of a newly built new energy power plant; Hgd t γ represents the other fixed costs invested in conductor fault repair during the operation of the newly built new energy power plant in year t; γ represents the expected number of conductor faults per year.

[0122] Based on existing conductor maintenance cost information for new energy power plants, it can be determined that the cost of a single conductor fault repair during the operation of a newly built new energy power plant includes labor costs, material costs, equipment rental costs, and depreciation costs of maintenance equipment. The cross-sectional area of ​​the conductor only affects material costs, but the change in material costs caused by the cross-sectional area accounts for a very small proportion of the cost of a single conductor fault repair. Therefore, it can be considered that the change in material costs caused by the cross-sectional area of ​​the conductor does not affect the size of the cost of a single conductor fault repair. Other fixed costs invested in conductor fault repair each year during the operation of a newly built new energy power plant include maintenance equipment costs and fixed wages for maintenance personnel.

[0123] The methods for calculating the estimated number of conductor failures per year include:

[0124] γ=C / A

[0125] Where A is the conductor cross-sectional area; C is the conductor fault constant.

[0126] Based on the maintenance cost information of the first conductor of existing new energy power plants, it can be known that the expected number of conductor failures per year is inversely proportional to the cross-sectional area of ​​the conductor. Based on the above analysis results, the above formula for calculating the expected number of conductor failures per year is proposed.

[0127] Therefore, we obtain

[0128] Based on the above calculation results, the formula for calculating total cost information can be obtained as follows:

[0129]

[0130] By differentiating the total cost information S with respect to the conductor cross-sectional area A and setting dS / dA = 0, the economic cross-sectional area A1 corresponding to the minimum annual cost can be obtained.

[0131] when hour;

[0132] The economic cross-sectional area corresponding to the minimum annual cost

[0133] The method for estimating conductor heat loss and selecting conductor cross-section in new energy engineering provided by this invention has at least the following technical effects or advantages:

[0134] 1. By simulating the output of a new energy power plant, the initial expected power of the new power plant is obtained to predict its initial output. Then, by combining the power generation information of existing new energy power plants, the expected power for each year during the operation of the new power plant is predicted. Based on the expected power for each year during the operation of the new power plant, the heat loss information of the conductors under various conductor cross-sectional areas during the operation of the new power plant is obtained to estimate the annual average heat loss power of the conductors under various conductor cross-sectional areas during the operation of the new power plant. This invention provides a method for estimating the conductor heat loss of new energy projects that is more consistent with the actual output characteristics of new energy projects than existing methods that often rely on obtaining operating data from similar existing power plants to predict the output of the new power plant and then calculating the annual average heat loss power of the conductors under different conductor cross-sectional areas. This solves the technical problem that existing methods for estimating conductor heat loss of new energy projects fail to consider the actual output characteristics of the new energy projects, making it difficult to accurately estimate the conductor heat loss and thus difficult to accurately obtain the economic cross-section of the conductors.

[0135] 2. By making the initial desired power Q′ the g-th output power Q that appears in the simulation results of the new energy power plant output. g The output power Q of the g-th type in the simulation results of the new energy power plant output g The probability of occurrence β g It is obtained by direct calculation; although the initial expected power Q′ obtained by this method does not take into account some objective factors that cannot be taken into account in the simulation of the output of new energy power plants, the calculation is convenient and simple.

[0136] 3. By adding the corresponding g-th type of output power Q to the calculation of the initial expected power Q′ g The assigned weight coefficient a gThis method allows for the artificial adjustment of the initial expected power Q′, enabling the calculation of the initial expected power Q′ to take into account some objective factors that cannot be considered in the simulation of the output of new energy power plants (such as: when the power generation in the simulation of the output of new energy power plants is higher than the grid load, resulting in the problem of wind and solar curtailment, the excess power generation will become ineffective power, etc.). This makes the calculation of the initial expected power Q′ obtained by this method more complex, but the calculation results are more accurate.

[0137] 4. By obtaining the unit-scale power generation of existing new energy power plants in each year within the statistical period; obtaining the change in unit-scale power generation of existing new energy power plants between two adjacent years within the statistical period; and then obtaining the average change in unit-scale power generation of existing new energy power plants between two adjacent years within the statistical period, and using the average output power change rate of existing new energy power plants between two adjacent years within the statistical period as the expected average output power change rate of newly built new energy power plants during the operation period, the expected power of newly built new energy power plants in each year during the operation period can be calculated.

[0138] The above are merely specific application examples of the present invention and do not constitute any limitation on the scope of protection of the present invention. All technical solutions formed by equivalent transformation or equivalent substitution fall within the scope of protection of the present invention.

Claims

1. A method for estimating conductor heat loss in new energy engineering, characterized in that: Includes the following steps: Step 1: Obtain the power generation information of existing new energy power plants, and obtain the initial expected power of the new energy power plant through power output simulation. Step 2: Based on the power generation information and the initial expected power, obtain the conductor heat loss information under various conductor cross-sectional areas during the operation of the newly built new energy power station, so as to complete the estimation of the annual average conductor heat loss power under various conductor cross-sectional areas during the operation of the newly built new energy power station. The power generation information includes the unit-scale power generation of the existing new energy power plants in each year within the statistical period. Step 2 includes: S1: Based on the power generation information and the initial expected power, obtain the expected power of the newly built new energy power station for each year during its operation; S2: Based on the expected power of the newly built new energy power station in each year during its operation, obtain the average calculated current of the newly built new energy power station in each year during its operation. S3: Based on the average calculated current of the newly built new energy power station in each year during its operation, obtain the conductor heat loss information of the newly built new energy power station under various conductor cross-sectional areas during its operation. In step S1, based on the power generation information, the average output power change rate of the existing new energy power plant in two consecutive years within the statistical period is obtained; then, based on the initial expected power and the average output power change rate, the expected power of the newly built new energy power plant in each year during its operation is obtained. The method for calculating the average output power change rate includes: ;W z c represents the unit-scale power generation of the existing new energy power plant in the z-th year within the statistical period; z represents the statistical period of the existing new energy power plant; and V represents the average output power change rate. The calculation method for the expected power output of the newly built new energy power plant in each year during its operation includes: Where t is the year the newly built new energy power plant is put into operation; Q' is the initial expected power; Q t Let V be the expected power output of the newly built new energy power plant in year t during its operation; V is the average output power change rate.

2. The method for estimating conductor heat loss in new energy projects according to claim 1, characterized in that: The method for calculating the initial expected power includes: Q g The g-th output power that appears in the simulation results of the power output of the new energy power plant; β g The output power Q of the g-th type in the simulation results of the power output of the new energy power plant g The probability of occurrence; y is the number of different output powers in the simulation results of the new energy power plant output; Q' is the initial expected power.

3. The method for estimating conductor heat loss in new energy engineering according to claim 1, characterized in that: The method for calculating the initial expected power includes: Q g The g-th output power that appears in the simulation results of the power output of the new energy power plant; β g The output power Q of the g-th type in the simulation results of the power output of the new energy power plant g The probability of occurrence; a g To correspond to the g-th type of output power Q g The assigned weighting coefficient; y is the number of different output powers in the simulation results of the new energy power plant output; Q' is the initial expected power.

4. The method for estimating conductor heat loss in new energy projects according to claim 1, characterized in that: The calculation method for the average annual current of the newly built new energy power plant during its operation includes: Where U is the nominal line voltage of the conductor during operation; t is the year the newly built new energy power station has been in operation; Q t Let I be the expected power output of the newly built new energy power plant in year t during its operation; t Let t be the average calculated current of the newly built new energy power plant during its operation in year t.

5. The method for estimating conductor heat loss in new energy projects according to claim 1, characterized in that: In S3, the conductor heat loss information includes the average annual heat loss power of the conductors under various conductor cross-sectional areas during the operation of the newly built new energy power station. The calculation method for the annual average heat loss power of the conductor in year t under various conductor cross-sectional areas during the operation of the newly built new energy power plant includes: ;where P t I represents the average annual heat loss power of the conductors in year t under various conductor cross-sectional areas during the operation of the newly built new energy power plant; t The average calculated current of the newly built new energy power station in year t during its operation; t is the year in which the newly built new energy power station operates; ρ is the resistivity of the conductor; L is the total length of the line of the newly built new energy power station; A is the cross-sectional area of ​​the conductor.

6. A method for selecting conductor cross-section in a new energy project, characterized in that: The method for estimating conductor heat loss in new energy projects according to any one of claims 1-5 includes the following steps: S1: Obtain conductor heat loss information under various conductor cross-sectional areas during the operation of the newly built new energy power station; S2: Based on the conductor heat loss information, obtain conductor heat loss cost information, which includes conductor heat loss cost under various conductor cross-sectional areas during the operation of the newly built new energy power station. S3: Based on the conductor heat loss cost information and the conductor construction and maintenance costs of the new energy power station under various conductor cross-sectional areas, obtain the total conductor cost information, which includes the total conductor cost of the new energy power station under various conductor cross-sectional areas within its maximum operating life. S4: Based on the total cost information of the conductor, select the economically optimal conductor cross-sectional area to complete the conductor cross-section selection for the new energy project.

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