Direct-current submarine cable section selection method for offshore wind power delivery project

Abstract

The invention discloses an offshore wind power transmission project DC submarine cable section selection method, which comprises the following steps: collecting historical operation data of a wind power plant, carrying out probability distribution fitting on the historical operation data to obtain a generation power probability distribution function, and establishing a wind curtailment loss function according to the generation power probability distribution function; obtaining related data of submarine cable engineering to establish a submarine cable cost function; based on the wind curtailment loss function and the submarine cable manufacturing cost function, a submarine cable full-life-cycle cost function is obtained, derivation about the submarine cable cross section is conducted on the submarine cable full-life-cycle cost function, and an optimal submarine cable cross section value is obtained; and laying the submarine cable according to the selected optimal submarine cable section value, continuously monitoring the power generation condition of the wind power plant, the operation state of the submarine cable and the actual expense in the operation process of the wind power plant project, and performing comparison, adjustment and optimization. According to the method, factors such as wind curtailment loss and submarine cable manufacturing cost are comprehensively considered, so that optimal selection of the direct-current submarine cable section is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of offshore wind power, and particularly relates to a method for selecting the cross-section of a DC submarine cable for an offshore wind power transmission project. Background Art

[0002] In the field of offshore wind power, after the power of a wind farm is converged by an offshore converter station, it needs to be transmitted to an onshore centralized control station through a DC submarine cable. With the large-scale development of offshore wind power, several wind farm clusters form GW-level large wind farms. However, the probability of such wind farms operating at full capacity is extremely low. If the cross-section of the DC submarine cable is determined only based on the rated installed capacity, although it can ensure the theoretical upper limit of power transmission, it will lead to a significant increase in project cost, thus greatly increasing the initial investment cost of the project; on the contrary, if the cross-section of the submarine cable is selected too small, it cannot carry the power output during the peak power generation of the wind farm, which will inevitably lead to wind abandonment losses and affect the power generation efficiency of the wind farm. Therefore, how to accurately balance the wind abandonment loss and the submarine cable cost, comprehensively consider the life cycle cost, and scientifically and reasonably select the cross-section of the DC submarine cable has become a key problem to be solved urgently.

[0003] Chinese Patent with Publication No. CN106355284A discloses a method for optimizing the selection of outgoing lines of a wind farm, including the following steps: S1: respectively construct a thermal circuit model of a power cable and a stochastic model of wind power generation environmental factors; S2: construct a linearized model of the temperature of the power cable core, and calculate the semi-invariants of each order of each random variable; S3: obtain the semi-invariants of each order of the cable core temperature according to the properties and definitions of the semi-invariants; S4: use the Gram-Charlier series expansion combined with the semi-invariants of each order of the cable core temperature to obtain the probability density function and the over-limit probability of the state variable core temperature, so as to carry out the optimized selection. The invention comprehensively considers the randomness of current and temperature, the cable thermal circuit model and the high-order moments of temperature distribution to optimize the selection of outgoing cables, but does not fully consider important factors such as the actual wind abandonment probability loss of the wind farm, which may lead to deviations in the selection scheme during actual operation, and fails to fully balance the power transmission demand and economy, thus causing unnecessary capital investment or resource waste. Summary of the Invention

[0004] The purpose of the invention is to provide a method for selecting the cross-section of a DC submarine cable for an offshore wind power transmission project, which realizes the optimized selection of the cross-section of the DC submarine cable by comprehensively considering various factors such as wind abandonment loss and submarine cable cost.

[0005] The technical solution of the invention is as follows:

[0006] On the one hand, the invention provides a method for selecting the cross-section of a DC submarine cable for an offshore wind power transmission project, including the following steps:

[0007] Collect the historical operation data of the wind farm, perform probability distribution fitting on the historical operation data of the wind farm to obtain the power generation probability distribution function, and establish a curtailment loss function according to the power generation probability distribution function.

[0008] Obtain the relevant data of the submarine cable project, and establish a submarine cable construction cost function according to the relevant data of the submarine cable project.

[0009] Based on the curtailment loss function and the submarine cable construction cost function, obtain the submarine cable life cycle cost function, and take the derivative of the submarine cable life cycle cost function with respect to the submarine cable cross-section to obtain the optimal submarine cable cross-section value.

[0010] Lay the submarine cable according to the selected optimal submarine cable cross-section value, continuously monitor the power generation situation of the wind farm, the operation status of the submarine cable and the actual cost expenditure during the operation of the wind farm project, and compare with the theoretical calculation results; if there is a deviation, adjust and optimize the relevant parameters.

[0011] Preferably, the curtailment loss function is expressed as the integral of the curtailment power over a certain time period T:

[0012]

[0013] In the formula, L wind is the curtailment loss function; P is the power generation power of the wind farm; ΔP is the curtailment power; f(P) is the power generation probability distribution function of the wind farm.

[0014] When the power generation power P of the wind farm > P Cable , curtailment loss occurs, and the curtailment power is solved as follows:

[0015] ΔP = max(0, P - P cable )

[0016] In the formula, P is the power generation power of the wind farm; P cable is the transmission capacity of the DC cable.

[0017] When the voltage is constant, the transmission capacity of the DC cable is solved as follows:

[0018] P cable = kS

[0019] In the formula, k is a coefficient related to the submarine cable material and heat dissipation conditions; S is the submarine cable cross-section.

[0020] Preferably, the submarine cable construction cost function is expressed as:

[0021] C cable = L total ·C unit

[0022] In the formula, C cableis the cost function of submarine cable, L total is the total laying length of submarine cable; C unit is the cost per unit length of submarine cable.

[0023] The cost per unit length of the submarine cable C unit is solved as follows:

[0024] C unit = C m + C p + C t

[0025] In the formula, C m is the basic material cost; C p is the processing additional cost; C t is the transportation and installation cost.

[0026] The basic material cost C m is solved as follows:

[0027] C m = mS

[0028] In the formula, m is the unit price of basic materials per unit cross-section of the submarine cable; S is the cross-section of the submarine cable.

[0029] The processing additional cost C p is solved as follows:

[0030] C p = pS 2

[0031] In the formula, p is the processing technology related coefficient; S is the cross-section of the submarine cable.

[0032] The transportation and installation cost C t is solved as follows:

[0033] C t = tSL

[0034] In the formula, t is the transportation and installation unit price per unit cross-section and per unit length; S is the cross-section of the submarine cable; L is the length of the submarine cable.

[0035] Preferably, the full life cycle cost function of the submarine cable is differentiated with respect to the cross-section of the submarine cable, and the specific value of the optimal cross-section of the submarine cable is obtained as follows:

[0036] The full life cycle cost function of the submarine cable is expressed as:

[0037] C total = C cable + v·L wind

[0038] In the formula, C total is the full life cycle cost function of the submarine cable; Ccable is the cost function of submarine cable; v is the value of unit curtailment loss; L wind is the curtailment loss function.

[0039] The derivative of the submarine cable's life cycle cost function with respect to the submarine cable cross-section is expressed as:

[0040]

[0041] For the submarine cable cost function C cable the derivative is expressed as:

[0042]

[0043] The derivative of the curtailment loss function is obtained according to the derivative rule of variable upper limit integral and the derivative rule of composite function.

[0044] Let Solve through numerical calculation methods to obtain the optimal submarine cable cross-section value.

[0045] On the other hand, the present invention provides a DC submarine cable cross-section selection system for an offshore wind power transmission project, including a curtailment loss construction module, a cost construction module, a submarine cable cross-section optimization module, and a submarine cable laying and monitoring optimization module.

[0046] The curtailment loss construction module is used to collect the historical operation data of the wind farm, fit the probability distribution of the historical operation data of the wind farm to obtain the power generation probability distribution function, and establish a curtailment loss function according to the power generation probability distribution function.

[0047] The cost construction module is used to obtain the relevant data of the submarine cable project and establish a submarine cable cost function according to the relevant data of the submarine cable project.

[0048] The submarine cable cross-section optimization module is used to obtain the submarine cable life cycle cost function based on the curtailment loss function and the submarine cable cost function, and take the derivative of the submarine cable life cycle cost function with respect to the submarine cable cross-section to obtain the optimal submarine cable cross-section value.

[0049] The submarine cable laying and monitoring optimization module is used to lay the submarine cable according to the selected optimal submarine cable cross-section value, continuously monitor the power generation situation of the wind farm, the operation status of the submarine cable, and the actual cost expenditure during the operation of the wind farm project, and compare with the theoretical calculation results; if there is a deviation, adjust and optimize the relevant parameters.

[0050] Preferably, the curtailment loss function in the curtailment loss construction module is expressed as the integral of the curtailment power within a certain time period T:

[0051]

[0052] In the formula, Lwind is the curtailment loss function; P is the power generation of the wind farm; ΔP is the curtailment power; f(P) is the probability distribution function of the power generation of the wind farm.

[0053] When the power generation of the wind farm P > P cable , curtailment loss occurs, and the curtailment power is solved as follows:

[0054] ΔP = max(0, P - P cable )

[0055] In the formula, P is the power generation of the wind farm; P cable is the transmission capacity of the DC cable.

[0056] When the voltage is constant, the transmission capacity of the DC cable is solved as follows:

[0057] P cable = kS

[0058] In the formula, k is the coefficient related to the material of the submarine cable and the heat dissipation condition; S is the cross-section of the submarine cable.

[0059] Preferably, the submarine cable construction cost function in the submarine cable construction cost module is expressed as:

[0060] C cable = L total ·C unit

[0061] In the formula, C cable is the submarine cable construction cost function, L total is the total laying length of the submarine cable; C unit is the unit length construction cost of the submarine cable.

[0062] The unit length construction cost C of the submarine cable unit is solved as follows:

[0063] C unit = C m + C p + C t

[0064] In the formula, C m is the basic material cost; C p is the processing additional cost; C t is the transportation and installation cost.

[0065] The basic material cost C m is solved as follows:

[0066] C m = mS

[0067] In the formula, m is the unit cross-section basic material unit price of the submarine cable; S is the cross-section of the submarine cable.

[0068] The additional processing cost C p is solved as follows:

[0069] C p = pS 2

[0070] where p is the processing technology related coefficient; S is the submarine cable cross-section.

[0071] The transportation and installation cost C t is solved as follows:

[0072] C t = tSL

[0073] where t is the transportation and installation unit price per unit cross-section per unit length; S is the submarine cable cross-section; L is the submarine cable length.

[0074] Preferably, in the submarine cable cross-section optimization module, the derivative of the submarine cable life cycle cost function with respect to the submarine cable cross-section is obtained, and the optimal submarine cable cross-section value is specifically:

[0075] The submarine cable life cycle cost function is expressed as:

[0076] C total = C cable + v·L wind

[0077] where C total is the submarine cable life cycle cost function; C cable is the submarine cable construction cost function; v is the unit value of abandoned wind loss; L wind is the abandoned wind loss function.

[0078] The derivative of the submarine cable life cycle cost function with respect to the submarine cable cross-section is expressed as:

[0079]

[0080] For the derivative of the submarine cable construction cost function C cable is expressed as:

[0081]

[0082] The derivative of the abandoned wind loss function is obtained according to the derivative rule of variable upper limit integral and the derivative rule of composite function.

[0083] Let Solve by numerical calculation method to obtain the optimal submarine cable cross-section value.

[0084] On the other hand, the present invention further provides an electronic device, which includes: a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the method for selecting the cross-section of a DC submarine cable for an offshore wind power transmission project as described in any embodiment of the present invention is implemented.

[0085] On the other hand, the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the method for selecting the cross-section of a DC submarine cable for an offshore wind power transmission project as described in any embodiment of the present invention is implemented.

[0086] Compared with the prior art, the present invention has the following technical effects:

[0087] By constructing a curtailment loss function and a submarine cable cost function, the present invention comprehensively considers the randomness of wind power generation and the economy of submarine cables, and determines the optimal cross-section value of the submarine cable. It can reduce the curtailment loss while optimizing the life-cycle cost of the submarine cable. It not only improves the utilization efficiency of the submarine cable but also reduces the overall project cost. After the submarine cable is laid, through continuous monitoring and optimization, it further ensures that the actual operation results are consistent with the theoretical expectations, thus achieving the dual goals of high efficiency and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Figure 1 is the overall flowchart of the method for selecting the cross-section of a DC submarine cable for an offshore wind power transmission project described in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0089] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present application and with reference to the accompanying drawings.

[0090] Embodiment 1

[0091] This embodiment provides a method for selecting the cross-section of a DC submarine cable for an offshore wind power transmission project. Referring to Figure 1 as shown, the method includes the following steps:

[0092] Collect historical operation data of the wind farm. Set the installed capacity of the wind farm as P rated (unit: MW), perform probability distribution fitting to obtain the power generation probability distribution function f(P), which reflects the probability of different power generation levels, and establish a curtailment loss function based on the power generation probability distribution function.

[0093] As a preferred implementation of this embodiment, the curtailment loss function is expressed as the integral of the curtailment power over a certain time period T (unit: h):

[0094]

[0095] In the formula, L wind is the curtailment loss function; P is the power generation of the wind farm; ΔP is the curtailment power; f(P) is the probability distribution function of the power generation of the wind farm. Here, no restriction is imposed on the selected probability distribution, and an appropriate probability distribution (including normal distribution, uniform distribution, exponential distribution, etc.) can be selected according to the data characteristics and actual requirements to determine the appropriate probability distribution function f(P).

[0096] When the power generation of the wind farm P > P cable , curtailment loss occurs, and the curtailment power is solved as follows:

[0097] ΔP = max(0, P - P cable )

[0098] In the formula, P is the power generation of the wind farm; P cable is the transmission capacity of the DC cable.

[0099] When the voltage is constant, the transmission capacity P cable of the DC submarine cable is related to the cable cross-section S and can be expressed as:

[0100] P cable = kS

[0101] In the formula, k is a coefficient related to the cable material and heat dissipation conditions (unit: MW / mm 2 ), and the coefficient k can be specifically determined according to the power engineering manual to calculate the current-carrying capacity of the corresponding cable cross-section. The voltage * current is the transmission capacity. When the voltage is constant, the transmission capacity is only related to the cross-section; S is the cable cross-section.

[0102] Obtain the relevant data of the submarine cable project and establish a submarine cable construction cost function according to the relevant data of the submarine cable project.

[0103] As a preferred implementation manner of this embodiment, the submarine cable construction cost function is expressed as:

[0104] C cable = L total ·C unit

[0105] In the formula, C cable is the submarine cable construction cost function, L total is the total length of the submarine cable laying; C unit is the construction cost per unit length of the submarine cable.

[0106] The submarine cable construction cost is not only related to the cable cross-section S, but also affected by many factors such as raw material cost, production process complexity, transportation and installation difficulty, etc. The construction cost per unit length C unit of the submarine cable is solved as follows:

[0107] C unit = C m + C p + C t

[0108] Wherein, C m is the basic material cost; C p is the processing additional cost; C t is the transportation and installation cost.

[0109] The basic material cost C m has an approximately linear relationship with the submarine cable cross-section S. The basic material cost C m is solved as follows:

[0110] C m = mS

[0111] Wherein, m is the basic material unit price per unit cross-section of the submarine cable (unit: yuan / mm 2 ); S is the submarine cable cross-section. The processing additional cost C p is solved as follows:

[0112] C p = pS 2

[0113] Wherein, p is the processing technology related coefficient (unit: yuan / mm 4 ), and as the submarine cable cross-section increases, the processing difficulty increases non-linearly; S is the submarine cable cross-section.

[0114] The transportation and installation cost C t is solved as follows:

[0115] C t = tSL

[0116] Wherein, t is the transportation and installation unit price per unit cross-section and per unit length; S is the submarine cable cross-section; L is the submarine cable length.

[0117] Based on the curtailment loss function and the submarine cable construction cost function, the submarine cable life cycle cost function is obtained, and the derivative of the submarine cable life cycle cost function with respect to the submarine cable cross-section is taken to obtain the optimal submarine cable cross-section value.

[0118] As a preferred implementation manner of this embodiment, taking the derivative of the submarine cable life cycle cost function with respect to the submarine cable cross-section, the specific optimal submarine cable cross-section value is:

[0119] The submarine cable life cycle cost function is expressed as:

[0120] C total = C cable + v·L wind

[0121] In the formula, C total is the total life cycle cost function of the submarine cable; C cable is the construction cost function of the submarine cable; v is the value of unit wind curtailment loss; L wind is the wind curtailment loss function.

[0122] In order to find the optimal cross-section of the submarine cable, the total life cycle cost function of the submarine cable is differentiated with respect to the cross-section of the submarine cable:

[0123]

[0124] For the construction cost function C cable of the submarine cable, the differentiation is expressed as:

[0125]

[0126] The differentiation of the wind curtailment loss function is obtained according to the differentiation rule of variable upper limit integral and the differentiation rule of composite function (the specific derivation process depends on the form of the f(P) function).

[0127] Let Solve by numerical calculation methods (such as Newton iteration method, etc.) to obtain the optimal cross-section value of the submarine cable.

[0128] Lay the submarine cable according to the selected optimal cross-section value of the submarine cable. During the operation of the wind farm project, continuously monitor the power generation situation of the wind farm, the operation status of the submarine cable, and the actual cost expenditure, and compare with the theoretical calculation results; if there is a deviation, adjust and optimize the relevant parameters.

[0129] Through the method described in this embodiment, while ensuring the reliable transmission of offshore wind power, it can effectively reduce the total life cycle cost of the submarine cable and improve the economic benefits and sustainable development ability of the offshore wind power project.

[0130] Embodiment 2

[0131] Correspondingly, this embodiment provides a DC submarine cable cross-section selection system for an offshore wind power transmission project. The system is used to implement the DC cable cross-section selection method for an offshore wind power transmission project as described in any embodiment of the present invention, including a wind curtailment loss construction module, a construction cost construction module, a submarine cable cross-section optimization module, and a submarine cable laying and monitoring optimization module.

[0132] The wind curtailment loss construction module is used to collect the historical operation data of the wind farm, fit the probability distribution of the historical operation data of the wind farm to obtain the power generation probability distribution function, and establish a wind curtailment loss function according to the power generation probability distribution function.

[0133] The construction cost construction module is used to obtain the relevant data of the submarine cable project and establish a construction cost function of the submarine cable according to the relevant data of the submarine cable project.

[0134] The submarine cable cross-section optimization module is used to obtain the total life-cycle cost function of the submarine cable based on the curtailment loss function and the submarine cable construction cost function, and take the derivative of the total life-cycle cost function of the submarine cable with respect to the submarine cable cross-section to obtain the optimal submarine cable cross-section value.

[0135] The submarine cable laying and monitoring optimization module is used to lay the submarine cable according to the selected optimal submarine cable cross-section value, continuously monitor the power generation situation of the wind farm, the operation status of the submarine cable, and the actual cost expenditure during the operation of the wind farm project, and compare with the theoretical calculation results; if there is a deviation, adjust and optimize the relevant parameters.

[0136] As a preferred implementation manner of this embodiment, the curtailment loss function in the curtailment loss construction module is expressed as the integral of the curtailment power over a certain time period T:

[0137]

[0138] In the formula, L wind is the curtailment loss function; P is the power generation power of the wind farm; ΔP is the curtailment power; f(P) is the probability distribution function of the power generation power of the wind farm.

[0139] When the power generation power P of the wind farm > P cable , curtailment loss occurs, and the curtailment power is solved as follows:

[0140] ΔP = max(0, P - P cable )

[0141] In the formula, P is the power generation power of the wind farm; P cable is the transmission capacity of the DC cable.

[0142] When the voltage is constant, the transmission capacity of the DC cable is solved as follows:

[0143] P cable = kS

[0144] In the formula, k is a coefficient related to the submarine cable material and heat dissipation conditions; S is the submarine cable cross-section.

[0145] As a preferred implementation manner of this embodiment, the submarine cable construction cost function in the submarine cable construction cost construction module is expressed as:

[0146] C cable = L total ·C unit

[0147] In the formula, C cable is the submarine cable construction cost function, L total is the total laying length of the submarine cable; C unit is the unit length construction cost of the submarine cable.

[0148] The cost per unit length C of the submarine cable unit is solved as follows:

[0149] C unit = C m + C p + C t

[0150] In the formula, C m is the basic material cost; C p is the processing additional cost; C t is the transportation and installation cost.

[0151] The basic material cost C m is solved as follows:

[0152] C m = mS

[0153] In the formula, m is the unit price of the basic material per unit cross-section of the submarine cable; S is the cross-section of the submarine cable.

[0154] The processing additional cost C p is solved as follows:

[0155] C p = pS 2

[0156] In the formula, p is the coefficient related to the processing technology; S is the cross-section of the submarine cable.

[0157] The transportation and installation cost C t is solved as follows:

[0158] C t = tSL

[0159] In the formula, t is the unit price of transportation and installation per unit cross-section and per unit length; S is the cross-section of the submarine cable; L is the length of the submarine cable.

[0160] As a preferred implementation mode of this embodiment, in the submarine cable cross-section optimization module, the derivative of the submarine cable life cycle cost function with respect to the submarine cable cross-section is obtained, and the specific optimal submarine cable cross-section value is:

[0161] The submarine cable life cycle cost function is expressed as:

[0162] C total = C cable + v·L wind

[0163] In the formula, C total is the submarine cable life cycle cost function; C cable is the submarine cable construction cost function; v is the value of unit abandoned wind loss; L windis the curtailment loss function.

[0164] The derivative of the total life cycle cost function of the submarine cable with respect to the cross-section of the submarine cable is expressed as:

[0165]

[0166] For the submarine cable construction cost function C cable The derivative is expressed as:

[0167]

[0168] The derivative of the curtailment loss function is obtained according to the derivative rule of variable upper limit integral and the derivative rule of composite function.

[0169] Let By solving through numerical calculation methods, the optimal cross-section value of the submarine cable is obtained.

[0170] Embodiment III

[0171] This embodiment provides an electronic device, which includes: a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the method for selecting the DC submarine cable cross-section of the offshore wind power transmission project as described in any embodiment of the present invention.

[0172] Embodiment IV

[0173] This embodiment provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the method for selecting the DC submarine cable cross-section of the offshore wind power transmission project as described in any embodiment of the present invention.

[0174] In the embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent the situation of A existing alone, A and B existing simultaneously, and B existing alone. Where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one of the following" and its similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0175] Those of ordinary skill in the art can realize that the various units and algorithm steps described in the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. A professional technician can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0176] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0177] In several embodiments provided in this application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (hereinafter referred to as ROMs), random access memories (hereinafter referred to as RAMs), magnetic disks, or optical discs that can store program codes.

[0178] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A method for selecting the cross-section of a DC submarine cable for an offshore wind power transmission project, characterized in that: The following steps are involved: Collect historical operation data of wind farms, perform probability distribution fitting on the historical operation data of wind farms to obtain the probability distribution function of power generation, and establish the wind abandonment loss function based on the probability distribution function of power generation; Obtaining submarine cable project related data, and establishing a submarine cable cost function based on the submarine cable project related data; Based on the wind abandonment loss function and the submarine cable cost function, the submarine cable life cycle cost function is obtained, and the submarine cable life cycle cost function is derived with respect to the submarine cable cross section to obtain the optimal submarine cable cross section value; The submarine cable is laid according to the selected optimal submarine cable cross-section value. During the operation of the wind farm project, the wind farm power generation, the submarine cable operation status and the actual expenditure are continuously monitored and compared with the theoretical calculation results. If there is any deviation, the relevant parameters are adjusted and optimized.

2. The method for selecting the cross section of a DC submarine cable for an offshore wind power transmission project according to claim 1 is characterized in that: The wind curtailment loss function is expressed as the integral of the wind curtailment power within a certain time period T: Where, L wind is the wind abandonment loss function; P is the wind farm power generation; ΔP is the wind abandonment power; f(P) is the wind farm power generation probability distribution function; When the wind farm power generation P>P cable When , wind abandonment loss occurs, and the abandoned wind power is solved as follows: ΔP=max(0,PP cable ) Where, P is the power generated by the wind farm; P cable is the transmission capacity of the DC cable; When the voltage is constant, the transmission capacity of the DC cable is solved as follows: P cable =kS Where k is a coefficient related to the cable material and heat dissipation conditions; S is the cable cross section.

3. The method for selecting the cross-section of a DC submarine cable for an offshore wind power transmission project according to any one of claims 1 or 2, characterized in that: The cost function of the submarine cable is expressed as: C cable =L total ·C unit In the formula, C cable is the cost function of submarine cable, L total The total length of the submarine cable laid; C unit is the cost per unit length of submarine cable; The cost per unit length of the submarine cable is C unit The solution is as follows: C unit =C m +C p +C t In the formula, C m is the basic material cost; C p Additional cost for processing; C t Installation costs for transportation; The basic material cost C m The solution is as follows: C m =mS In the formula, m is the unit price of the basic material per unit cross-section of the submarine cable; S is the cross-section of the submarine cable; The additional processing cost C p The solution is as follows: C p =pS 2 Where, p is the processing technology correlation coefficient; S is the cross section of the submarine cable; The transportation and installation cost C t The solution is as follows: C t =tSL Where t is the unit price of transportation and installation per unit length of unit cross-section; S is the cross-section of the submarine cable; and L is the length of the submarine cable.

4. The method for selecting the cross-section of a DC submarine cable for an offshore wind power transmission project according to claim 3 is characterized in that: The cost function of the submarine cable life cycle is derived with respect to the cross section of the submarine cable, and the optimal cross section value of the submarine cable is obtained as follows: The cost function of the submarine cable life cycle is expressed as: C tital =C cable +v·L wind In the formula, C total is the cost function of the submarine cable throughout its life cycle; C cable is the cost function of submarine cable; v is the unit wind abandonment loss value; L wind is the wind abandonment loss function; The derivative of the cost function of the submarine cable's entire life cycle with respect to the cable cross section is expressed as: For the submarine cable cost function C cable The derivative of is expressed as: The derivation of the wind abandonment loss function is obtained according to the variable upper limit integral derivation rule and the composite function derivation rule; make The optimal cross-section value of the submarine cable is obtained by numerical calculation method.

5. A DC submarine cable section selection system for offshore wind power transmission projects, characterized in that: It includes wind abandonment loss building module, construction cost building module, submarine cable section optimization module and submarine cable laying and monitoring optimization module; A wind abandonment loss construction module is used to collect historical operation data of wind farms, perform probability distribution fitting on the historical operation data of wind farms to obtain a power generation probability distribution function, and establish a wind abandonment loss function based on the power generation probability distribution function; The cost construction module is used to obtain the relevant data of the submarine cable project and establish the submarine cable cost function according to the relevant data of the submarine cable project; The submarine cable cross-section optimization module is used to obtain the submarine cable life cycle cost function based on the wind abandonment loss function and the submarine cable cost function, and to derive the submarine cable life cycle cost function with respect to the submarine cable cross-section to obtain the optimal submarine cable cross-section value; The submarine cable laying and monitoring optimization module is used to lay submarine cables according to the selected optimal submarine cable cross-section value. During the operation of the wind farm project, it continuously monitors the wind farm power generation, submarine cable operation status and actual cost expenditure, and compares them with the theoretical calculation results; if there is any deviation, the relevant parameters are adjusted and optimized.

6. The DC submarine cable section selection system for offshore wind power transmission projects according to claim 5 is characterized in that: The wind abandonment loss function in the wind abandonment loss building module is expressed as the integral of the abandoned wind power within a certain time period T: Where, L wind is the wind abandonment loss function; P is the wind farm power generation; ΔP is the wind abandonment power; f(P) is the wind farm power generation probability distribution function; When the wind farm power generation P>P cable When , wind abandonment loss occurs, and the abandoned wind power is solved as follows: ΔP=max(0,PP cable ) Where, P is the power generated by the wind farm; P cable is the transmission capacity of the DC cable; When the voltage is constant, the transmission capacity of the DC cable is solved as follows: P cable =kS Where k is a coefficient related to the cable material and heat dissipation conditions; S is the cable cross section.

7. The DC submarine cable section selection system for an offshore wind power transmission project according to any one of claims 5 or 6, characterized in that: The submarine cable cost function in the submarine cable cost building module is expressed as: C cable =L total ·C unit In the formula, C cable is the cost function of submarine cable, L total The total length of the submarine cable laid; C unit is the cost per unit length of submarine cable; The cost per unit length of the submarine cable is C unit The solution is as follows: C unit =C m +C p +C t In the formula, C m is the basic material cost; C p Additional cost for processing; C t Installation costs for transportation; The basic material cost C m The solution is as follows: C m =mS In the formula, m is the unit price of the basic material per unit cross-section of the submarine cable; S is the cross-section of the submarine cable; The additional processing cost C p The solution is as follows: C p =pS 2 Where, p is the processing technology correlation coefficient; S is the cross section of the submarine cable; The transportation and installation cost C t The solution is as follows: C t =tSL Where t is the unit price of transportation and installation per unit length of unit cross-section; S is the cross-section of the submarine cable; and L is the length of the submarine cable.

8. The DC submarine cable section selection system for offshore wind power transmission projects according to claim 7 is characterized in that: In the submarine cable cross-section optimization module, the cost function of the submarine cable life cycle is derived with respect to the submarine cable cross-section, and the optimal submarine cable cross-section value is obtained as follows: The cost function of the submarine cable life cycle is expressed as: C total =C cable +v·L wind In the formula, C total is the cost function of the submarine cable throughout its life cycle; C cable is the cost function of submarine cable; v is the unit wind abandonment loss value; L wind is the wind abandonment loss function; The derivative of the cost function of the submarine cable's entire life cycle with respect to the cable cross section is expressed as: For the submarine cable cost function C cable The derivative of is expressed as: The derivation of the wind abandonment loss function is obtained according to the variable upper limit integral derivation rule and the composite function derivation rule; make The optimal cross-section value of the submarine cable is obtained by numerical calculation method.

9. An electronic device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method for selecting the cross-section of a DC submarine cable for an offshore wind power transmission project as described in any one of claims 1 to 4 when executing the computer program.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for selecting the cross-section of a DC submarine cable for an offshore wind power transmission project according to any one of claims 1 to 4 is implemented.

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