CN113297750B

CN113297750B - Cable model selection method and system for offshore wind power plant

Info

Publication number: CN113297750B
Application number: CN202110633254.7A
Authority: CN
Inventors: 杨翠茹; 汪政; 何衍和; 周原; 李志峰; 于是乎; 吕忠麟; 胡克
Original assignee: Guangdong Power Grid Co Ltd; Electric Power Research Institute of Guangdong Power Grid Co Ltd
Current assignee: Guangdong Power Grid Co Ltd; Electric Power Research Institute of Guangdong Power Grid Co Ltd
Priority date: 2021-06-07
Filing date: 2021-06-07
Publication date: 2022-06-10
Anticipated expiration: 2041-06-07
Also published as: CN113297750A

Abstract

The invention provides a cable model selection method and a cable model selection system for an offshore wind farm, wherein the method comprises the following steps: acquiring related parameters of a superconducting direct current cable, related parameters of an HVDC cable, related parameters of an HVAC cable, related parameters of a refrigerator and element parameters; establishing a cable model selection model according to the related parameters of the superconducting direct current cable, the related parameters of the HVDC cable, the related parameters of the HVAC cable, the related parameters of the refrigerator and the element parameters; acquiring the length of a cable to be laid of an offshore wind farm; and inputting the length of the cable to be laid into the cable model selection model, and outputting a cable model selection result. The invention provides a relatively comprehensive quantification method for selecting the grid-connected mode of the offshore wind farm, and has a positive effect on the practical application of propelling the superconducting cable.

Description

Cable model selection method and system for offshore wind power plant

Technical Field

The invention relates to the technical field of cable model selection, in particular to a cable model selection method and system for an offshore wind farm.

Background

The superconducting direct current cable has different electrical characteristics from the common cable, and the comparison between the operation benefit and the modification and maintenance cost of the superconducting direct current cable and the conventional power transmission mode judges whether the superconducting direct current cable can be applied to a wind power plant in a large scale. It is necessary to analyze the economic feasibility of the offshore wind power adopting a superconducting direct current cable access mode.

At present, a selection method of an offshore wind farm grid-connection mode has a certain research foundation, but most of the research works do not consider a grid-connection scheme of a superconducting direct current cable, cost composition analysis on access of the superconducting cable in the research work which considers the grid-connection scheme of the superconducting direct current cable in a small amount is often simpler, a cost calculation method for applying the superconducting direct current cable to the offshore wind farm grid-connection is still relatively deficient, and finally obtained boundary conditions are often single and have lower reliability.

Disclosure of Invention

In order to solve the existing problems, the invention provides a cable type selection method and a cable type selection system for an offshore wind farm.

The invention provides a cable type selection method for an offshore wind farm in a first aspect, which comprises the following steps:

acquiring related parameters of a superconducting direct current cable, related parameters of an HVDC cable, related parameters of an HVAC cable, related parameters of a refrigerator and element parameters; establishing a cable model selection model according to the related parameters of the superconducting direct current cable, the related parameters of the HVDC cable, the related parameters of the HVAC cable, the related parameters of the refrigerator and the element parameters;

acquiring the length of a cable needing to be laid of an offshore wind farm; inputting the length of the cable to be laid into the cable model selection model, and outputting a cable model selection result;

wherein the related parameters of the superconducting direct current cable comprise: the method comprises the following steps of (1) construction cost of the superconducting direct current converter station, operation and maintenance cost of the superconducting direct current converter station, loss of the superconducting direct current converter station, pollutant discharge amount of a superconducting direct current grid-connected system, rated current of a superconducting direct current cable, purchase price of the superconducting direct current cable and laying cost of the superconducting direct current cable in unit length;

the HVDC cable related parameters comprise: the method comprises the following steps of high-voltage direct current converter station construction cost, high-voltage direct current converter station operation and maintenance cost, HVDC grid-connected system pollutant emission, HVDC cable purchase price, unit length HVDC cable laying cost, unit length HVDC cable loss and high-voltage direct current converter station loss;

the HVAC cable related parameters include: the method comprises the following steps of (1) constructing cost of a high-voltage alternating-current transformer substation, operation and maintenance cost of the high-voltage alternating-current transformer substation, HVAC reactive compensation cost, HVAC cable purchase price, HVAC cable laying cost per unit length, HVAC cable loss per unit length and pollutant discharge amount of an HVAC grid-connected system;

the chiller-related parameters include: refrigerator performance parameters and refrigerator purchase price;

the element parameters include: current lead loss, joint resistance loss, excess conductor loss, cryogenic vessel loss, dewar pipe joint loss, liquid nitrogen flow loss, wind farm operating load factor, electricity price, operating time discount factor, blowdown cost factor.

Further, the cable model selection model comprises: a cable length minimum model and a cable length maximum model; wherein, the first and the second end of the pipe are connected with each other,

the cable length minimum model is:

A₁＝A_{construction of superconducting DC converter station}+A_{Operation and maintenance of superconducting direct current converter station}-A_{Construction of high-voltage AC transformer substation}-A_{High-voltage AC transformer substation operation and maintenance}-A_{Reactive compensation}；

P₁＝ρ[μ(P_{Current lead}+P_{Joint resistor}+P_{Transition conductor})+P_{Low temperature container}]+2μP_{Superconducting converter station losses}；

P₂＝(0.086εdρ+r)(P_{Dewar pipe}+P_{Dewar pipe joint}+P_{Flow of liquid nitrogen})；

Wherein l_minIs the minimum value of the cable length, A₁For the first cost, A_{Construction of superconducting DC converter station}Construction costs for superconducting direct current converter stations, A_{Operation and maintenance of superconducting direct current converter station}For the operation and maintenance costs of superconducting DC converter stations, A_{Construction of high-voltage AC transformer substation}For the construction cost of high-voltage AC substations, A_{High-voltage AC transformer substation operation and maintenance}For the operation and maintenance cost of high voltage AC transformer station, A_{Reactive compensation}For HVAC reactive compensation costs, P₁Is the first loss, rho is the refrigerator performance parameter, mu is the wind farm operating load factor, P_{Current lead}For current lead loss, P_{Joint resistor}For resistive losses of the joint, P_{Transition conductor}For excessive conductor loss, P_{Low temperature container}For cryogenic vessel depletion, P_{Superconducting converter station losses}For superconducting DC converter station losses, P₂For the second loss, ε is the electricity price, d is the running time discount factor, r is the refrigerator purchase price, P_{Dewar pipe}For Dewar tube losses, P_{Dewar pipe joint}For a loss of a Dewar coupling, P_{Flow of liquid nitrogen}Is the flow loss of liquid nitrogen, k is the cost coefficient of pollution discharge, Q_HTSFor superconducting DC grid-connected system pollutant discharge, Q_HVACFor HVAC grid-tied system pollutant emissions, X_HVACPurchase price for HVAC Cable, A_{HVAC installation per unit length}Cost of HVAC cabling per unit length, P_{HVAC Unit line loss}For unit length of HVAC cable loss, I_HTSFor the rated current, X, of a superconducting DC cable_HTSPurchase price for superconducting DC cables, A_{HTS unit length laying}The laying cost of the superconducting direct current cable is unit length;

the maximum model of the cable length is as follows:

A₂＝A_{construction of superconducting DC converter station}+A_{Superconducting materialOperation and maintenance of direct current converter station}-A_{Construction of high-voltage direct current converter station}-A_{Operation and maintenance of high-voltage direct-current converter station}；

Wherein l_maxAt maximum cable length, A₂For the second cost, A_{Construction of superconducting DC converter station}Construction costs for superconducting direct current converter stations, A_{Operation and maintenance of superconducting direct current converter station}For the operation and maintenance costs of superconducting DC converter stations, A_{Construction of high-voltage direct current converter station}For the construction costs of the HVDC converter station, A_{Operation and maintenance of high-voltage direct current converter station}For the operation and maintenance cost of the high-voltage direct-current converter station, P₁Is the first loss, rho is the refrigerator performance parameter, mu is the wind farm operating load factor, P_{Current lead}For current lead loss, P_{Joint resistor}For resistive losses of the joint, P_{Transition conductor}For excessive conductor loss, P_{Low temperature container}For cryogenic vessel depletion, P_{Superconducting converter station losses}For superconducting DC converter station losses, P₂For the second loss, ε is the electricity price, d is the running time discount factor, r is the refrigerator purchase price, P_{Dewar pipe}For Dewar tube losses, P_{Dewar pipe joint}For a loss of a Dewar coupling, P_{Flow of liquid nitrogen}Is the flow loss of liquid nitrogen, k is the cost coefficient of pollution discharge, Q_HTSFor superconducting DC grid-connected system pollutant discharge, Q_HVDCFor HVDC grid-connected system pollutant emissions, P_{High voltage direct current converter station loss}For losses in HVDC converter stations, X_HVDCPurchase price for HVDC cables, A_{HVDC laying per unit length}For unit length HVDC cable laying cost, P_{HVDC Unit line loss}For unit length of HVDC cable loss, I_HTSFor the rated current, X, of a superconducting DC cable_HTSPurchase price for superconducting DC cables, A_{HTS unit length laying}For unit length superconducting DC cable coatingAnd setting cost.

Further, the inputting the length of the cable to be laid into the cable model selection model and outputting a cable model selection result includes:

judging the size relation between the length of the cable to be laid and the minimum value of the length of the cable;

if the length of the cable to be laid is smaller than the minimum value of the length of the cable, the output cable is an HVAC cable in a type selection result;

if the length of the cable to be laid is larger than the minimum value of the length of the cable, judging the size relation between the length of the cable to be laid and the maximum value of the length of the cable; if the length of the cable to be laid is greater than the maximum length of the cable, the output cable is an HVDC cable;

and if the length of the cable to be laid is not less than the minimum length of the cable and not more than the maximum length of the cable, the type selection result of the output cable is the superconducting direct current cable.

Further, the construction cost of the superconducting direct current converter station is calculated by the following formula:

A_{construction of superconducting DC converter station}＝2*P_{HTS Total Capacity}*A_{Cost of superconducting DC converter station}；

Wherein A is_{Construction of superconducting DC converter station}For the construction costs, P, of superconducting direct current converter stations_{HTS Total Capacity}For total capacity of superconducting DC transmission, A_{Cost of superconducting DC converter station}The cost of the superconducting direct current converter station.

Further, the operation and maintenance cost of the superconducting direct current converter station is calculated by the following formula:

A_{operation and maintenance of superconducting direct current converter station}＝m*k_{Operation and maintenance}*A_{Construction of superconducting DC converter station}；

Wherein A is_{Operation and maintenance of superconducting direct current converter station}M is annual capital value coefficient, k is the operation and maintenance cost of the superconducting direct current converter station_{Operation and maintenance}For maintenance rates of operation, A_{Construction of superconducting DC converter station}The construction cost of the superconducting direct current converter station is reduced.

Further, the HVAC reactive compensation cost is calculated by the following formula:

A_{reactive compensation}＝A_{Cost per unit of reactive power compensation}*Q；

Wherein A is_{Reactive power compensation}For HVAC reactive compensation costs, A_{Cost per unit of reactive power compensation}Is the HVAC reactive compensation cost per unit length, and Q is the reactive compensation capacity required by the HVAC transmission system.

Further, the construction cost of the high-voltage alternating-current substation is calculated by the following formula:

A_{construction of high-voltage AC transformer substation}＝2*P_{HVAC Total Capacity}*A_{Cost of high voltage AC substation}；

Wherein A is_{Construction of high-voltage alternating-current transformer substation}For the construction cost of high-voltage AC substations, P_{HVAC Total Capacity}For total capacity of high-voltage AC transmission, A_{High voltage ac substation cost}The cost of the high-voltage alternating-current transformer substation is reduced.

Further, the operation and maintenance cost of the high-voltage alternating-current substation is calculated by the following formula:

A_{high-voltage AC transformer substation operation and maintenance}＝m*(2*k_{Operation and maintenance}*P_{HVDC Total Capacity}+2*A_{High voltage AC substation communication}+2*A_{High voltage ac substation operation})；

Wherein A is_{Operation and maintenance of AC transformer substation}For the operation and maintenance cost of the high-voltage AC transformer station, m is the annual fund present value coefficient, k_{Operation and maintenance}For maintenance of the operation, P_{HVDC Total Capacity}For the total capacity of HVDC transmission, A_{High voltage AC substation communication}For the maintenance cost of the communication equipment of the high-voltage direct-current transformer substation, A_{High voltage ac substation operation}The operation cost of the high-voltage direct-current transformer substation is reduced.

The invention provides a cable type selection system of an offshore wind farm, which comprises:

the cable model selection model establishing module is used for acquiring related parameters of the superconducting direct current cable, related parameters of the HVDC cable, related parameters of the HVAC cable, related parameters of the refrigerator and element parameters; establishing a cable model selection model according to the related parameters of the superconducting direct current cable, the related parameters of the HVDC cable, the related parameters of the HVAC cable, the related parameters of the refrigerator and the element parameters;

the cable model selection result output module is used for acquiring the length of a cable needing to be laid in the offshore wind farm; inputting the length of the cable to be laid into the cable model selection model, and outputting a cable model selection result;

Further, the cable model selection model comprises: a cable length minimum model and a cable length maximum model; wherein the content of the first and second substances,

the cable length minimum model is:

Wherein l_minIs the minimum value of the cable length, A₁For the first cost, A_{Construction of superconducting DC converter station}Construction costs for superconducting direct current converter stations, A_{Operation and maintenance of superconducting direct current converter station}For the operation and maintenance costs of superconducting DC converter stations, A_{Construction of high-voltage AC transformer substation}For the construction costs of high-voltage AC substations, A_{High-voltage AC transformer substation operation and maintenance}For the operation and maintenance cost of high voltage AC transformer station, A_{Reactive compensation}For HVAC reactive compensation costs, P₁Is the first loss, rho is the refrigerator performance parameter, mu is the wind farm operating load factor, P_{Current lead}For current lead loss, P_{Joint resistor}For resistive losses of the joint, P_{Transition conductor}For excessive conductor loss, P_{Low temperature container}For cryogenic vessel depletion, P_{Superconducting converter station losses}For superconducting DC converter station losses, P₂For the second loss, ε is the electricity price, d is the running time discount factor, r is the refrigerator purchase price, P_{Dewar pipe}For Dewar tube losses, P_{Dewar pipe joint}For a loss of a Dewar coupling, P_{Flow of liquid nitrogen}Is the flow loss of liquid nitrogen, k is the pollution discharge cost coefficient, Q_HTSFor superconducting DC grid-connected system pollutant discharge, Q_HVACFor HVAC grid-tied system pollutant emissions, X_HVACPurchase price for HVAC Cable, A_{Unit length HVAC}Laying as a unit length HVAC cabling cost, P_{HVAC unit line loss}For unit length of HVAC cable loss, I_HTSIs a superconducting DC cableRated current, X_HTSPurchase price for superconducting DC cables, A_{HTS unit length laying}The laying cost of the unit length of the superconducting direct current cable is calculated;

the maximum model of the cable length is as follows:

A₂＝A_{construction of superconducting DC converter station}+A_{Operation and maintenance of superconducting direct current converter station}-A_{Construction of high-voltage direct current converter station}-A_{Operation and maintenance of high-voltage direct-current converter station}；

Wherein l_maxAt maximum cable length, A₂For the second cost, A_{Construction of superconducting DC converter station}Construction costs for superconducting direct current converter stations, A_{Operation and maintenance of superconducting direct current converter station}For the operation and maintenance costs of superconducting DC converter stations, A_{Construction of high-voltage direct current converter station}For the construction costs of the HVDC converter station, A_{Operation and maintenance of high-voltage direct-current converter station}For the operation and maintenance cost of the high-voltage direct-current converter station, P₁Is the first loss, rho is the refrigerator performance parameter, mu is the wind farm operating load factor, P_{Current lead}For current lead loss, P_{Joint resistor}For resistive losses of the joint, P_{Transition conductor}For excessive conductor loss, P_{Low temperature container}For cryogenic vessel depletion, P_{Superconducting converter station losses}For superconducting DC converter station losses, P₂For the second loss, ε is the electricity price, d is the running time discount factor, r is the refrigerator purchase price, P_{Dewar pipe}For Dewar tube losses, P_{Dewar pipe joint}For a loss of a Dewar coupling, P_{Flow of liquid nitrogen}Is the flow loss of liquid nitrogen, k is the cost coefficient of pollution discharge, Q_HTSIs a superconducting wireFlow and grid system pollutant discharge amount, Q_HVDCFor HVDC grid-connected system pollutant emissions, P_{High voltage direct current converter station loss}For losses in the HVDC converter station, X_HVDCPurchase price for HVDC cables, A_{HVDC laying per unit length}For unit length HVDC cable laying cost, P_{HVDC Unit line loss}For unit length of HVDC cable loss, I_HTSFor the rated current, X, of a superconducting DC cable_HTSPurchase price for superconducting DC cables, A_{HTS unit length laying}The cost is the laying cost of the unit length of the superconducting direct current cable.

Further, the cable type selection result output module includes a cable length judgment submodule configured to:

judging the size relation between the length of the cable to be laid and the minimum value of the length of the cable; if the length of the cable to be laid is smaller than the minimum value of the length of the cable, the output cable is an HVAC cable in a type selection result; if the length of the cable to be laid is larger than the minimum value of the length of the cable, judging the size relation between the length of the cable to be laid and the maximum value of the length of the cable; if the length of the cable to be laid is greater than the maximum length of the cable, the output cable is an HVDC cable; and if the length of the cable to be laid is not less than the minimum length of the cable and not more than the maximum length of the cable, the type selection result of the output cable is the superconducting direct current cable.

Compared with the prior art, the embodiment of the invention has the beneficial effects that:

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a flow chart of a cable model selection method for an offshore wind farm according to an embodiment of the present invention;

FIG. 2 is a graph comparing the life cycle cost of a superconducting DC cable and an HVAC cable provided by an embodiment of the present invention;

FIG. 3 is a graph comparing life cycle costs of a superconducting DC cable and a HVDC cable provided by an embodiment of the present invention;

FIG. 4 is a graph comparing life cycle costs of superconducting DC cables of different transport capacities and HVAC cables provided by one embodiment of the present invention;

FIG. 5 is a diagram of an apparatus for a cable sizing system for an offshore wind farm according to an embodiment of the present invention;

FIG. 6 is a diagram of an apparatus for a cable sizing system for an offshore wind farm according to another embodiment of the present invention;

fig. 7 is a block diagram of an electronic device according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be understood that the step numbers used herein are only for convenience of description and are not used as limitations on the order in which the steps are performed.

It is to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The terms "comprises" and "comprising" indicate the presence of the described features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The term "and/or" refers to and includes any and all possible combinations of one or more of the associated listed items.

A first aspect.

Referring to fig. 1, an embodiment of the present invention provides a cable model selection method for an offshore wind farm, including:

s10, acquiring related parameters of the superconducting direct current cable, related parameters of the HVDC cable, related parameters of the HVAC cable, related parameters of the refrigerator and parameters of elements; and establishing a cable model selection model according to the related parameters of the superconducting direct current cable, the related parameters of the HVDC cable, the related parameters of the HVAC cable, the related parameters of the refrigerating machine and the element parameters.

In a specific embodiment, the cable model selection model includes: a cable length minimum model and a cable length maximum model; wherein the content of the first and second substances,

the cable length minimum model is:

A₁＝A_{construction of superconducting direct current converter station}+A_{Operation and maintenance of superconducting direct current converter station}-A_{Construction of high-voltage AC transformer substation}-A_{High-voltage AC transformer substation operation and maintenance}-A_{Reactive compensation}；

Wherein l_minIs the minimum value of the cable length, A₁For the first cost, A_{Construction of superconducting DC converter station}Construction costs for superconducting direct current converter stations, A_{Operation and maintenance of superconducting direct current converter station}For the operation and maintenance costs of superconducting DC converter stations, A_{Construction of high-voltage AC transformer substation}Is highConstruction cost of AC-voltage substation, A_{High-voltage AC transformer substation operation and maintenance}For the operation and maintenance cost of high voltage AC transformer station, A_{Reactive compensation}For HVAC reactive compensation costs, P₁Is the first loss, rho is the refrigerator performance parameter, mu is the wind farm operating load factor, P_{Current lead}For current lead loss, P_{Joint resistor}For resistive losses of the joint, P_{Transition conductor}For excessive conductor loss, P_{Low temperature container}For cryogenic vessel depletion, P_{Superconducting converter station losses}For superconducting DC converter station losses, P₂For the second loss, ε is the electricity price, d is the running time discount factor, r is the refrigerator purchase price, P_{Dewar pipe}For Dewar tube losses, P_{Dewar pipe joint}For a loss of a Dewar coupling, P_{Flow of liquid nitrogen}Is the flow loss of liquid nitrogen, k is the cost coefficient of pollution discharge, Q_HTSFor superconducting DC grid-connected system pollutant discharge, Q_HVACFor HVAC grid-tied system pollutant emissions, X_HVACPurchase price for HVAC Cable, A_{HVAC installation per unit length}For unit length of HVAC cabling cost, P_{HVAC unit line loss}For unit length of HVAC cable loss, I_HTSFor the rated current, X, of a superconducting DC cable_HTSPurchase price for superconducting DC cables, A_{HTS unit length laying}The laying cost of the unit length of the superconducting direct current cable is calculated;

the maximum model of the cable length is as follows:

P₂＝(0.086εdρ+r)(P_{Dewar pipe}+P_{Dewar pipeJoint}+P_{Flow of liquid nitrogen})；

Wherein l_maxAt maximum cable length, A₂For the second cost, A_{Construction of superconducting DC converter station}Construction costs for superconducting direct current converter stations, A_{Operation and maintenance of superconducting direct current converter station}For the operation and maintenance costs of superconducting DC converter stations, A_{Construction of high-voltage direct current converter station}For the construction costs of the HVDC converter station, A_{Operation and maintenance of high-voltage direct-current converter station}For the operation and maintenance cost of the high-voltage direct-current converter station, P₁Is the first loss, rho is the refrigerator performance parameter, mu is the wind farm operating load factor, P_{Current lead}For current lead loss, P_{Joint resistor}For resistive losses of the joint, P_{Transition conductor}For excessive conductor loss, P_{Low temperature container}For cryogenic vessel depletion, P_{Superconducting converter station losses}For superconducting DC converter station losses, P₂For the second loss, ε is the electricity price, d is the running time discount factor, r is the refrigerator purchase price, P_{Dewar pipe}For Dewar tube losses, P_{Dewar pipe joint}For a loss of a Dewar coupling, P_{Flow of liquid nitrogen}Is the flow loss of liquid nitrogen, k is the cost coefficient of pollution discharge, Q_HTSFor superconducting DC grid-connected system pollutant discharge, Q_HVDCFor HVDC grid-connected system pollutant emissions, P_{High voltage direct current converter station loss}For losses in HVDC converter stations, X_HVDCPurchase price for HVDC cables, A_{HVDC laying per unit length}For unit length HVDC cable laying cost, P_{HVDC Unit line loss}For unit length of HVDC cable loss, I_HTSFor the rated current, X, of a superconducting DC cable_HTSPurchase price for superconducting DC cables, A_{HTS unit length laying}The cost is the unit length of the superconducting direct current cable.

Specifically, the method comprises the following steps:

the operation and maintenance cost of the superconducting direct current converter station is calculated by the following formula:

Wherein A is_{Operation and maintenance of superconducting direct current converter station}For operation of superconducting dc converter stationsDimension cost, m is the annual fund present value coefficient, k_{Operation and maintenance}For operation maintenance rates, A_{Construction of superconducting DC converter station}The construction cost of the superconducting direct current converter station is reduced.

The HVAC reactive compensation cost is calculated by the following formula:

A_{reactive compensation}＝A_{Unit reactive compensation cost}*Q；

Wherein, A_{Reactive compensation}For HVAC reactive compensation costs, A_{Cost per unit of reactive power compensation}Q is the reactive compensation capacity required by the HVAC transmission system for a unit length of HVAC reactive compensation cost.

The construction cost of the high-voltage alternating-current transformer substation is calculated by the following formula:

A_{construction of high-voltage alternating-current transformer substation}＝2*P_{HVAC Total Capacity}*A_{High voltage ac substation cost}；

Wherein A is_{Construction of high-voltage AC transformer substation}For the construction cost of high-voltage AC substations, P_{HVAC Total Capacity}For total capacity of high-voltage AC transmission, A_{Cost of high voltage AC substation}The cost of the high-voltage alternating-current transformer substation is reduced.

The operation and maintenance cost of the high-voltage alternating-current transformer substation is calculated by the following formula:

Wherein A is_{Operation and maintenance of AC transformer substation}The operation and maintenance cost of the high-voltage alternating-current transformer substation, m is the annual fund present value coefficient, k_{Operation and maintenance}For maintenance of the operation, P_{HVDC Total Capacity}For the total capacity of HVDC transmission, A_{High voltage AC substation communication}For the maintenance cost of the communication equipment of the high-voltage direct-current transformer substation, A_{High voltage ac substation operation}The operation cost of the high-voltage direct-current transformer substation is reduced.

S20, acquiring the length of a cable required to be laid of the offshore wind farm; and inputting the length of the cable to be laid into the cable model selection model, and outputting a cable model selection result.

In a specific embodiment, the step S20 includes:

The invention provides a cable model selection method for an offshore wind farm, which comprises the following steps: acquiring related parameters of a superconducting direct current cable, related parameters of an HVDC cable, related parameters of an HVAC cable, related parameters of a refrigerator and element parameters; establishing a cable model selection model according to the related parameters of the superconducting direct current cable, the related parameters of the HVDC cable, the related parameters of the HVAC cable, the related parameters of the refrigerator and the element parameters; acquiring the length of a cable to be laid of an offshore wind farm; and inputting the length of the cable to be laid into the cable model selection model, and outputting a cable model selection result. The invention provides a relatively comprehensive quantification method for selecting the grid-connected mode of the offshore wind farm, and has a positive effect on the practical application of propelling the superconducting cable.

In a specific embodiment, the life cycle cost calculation shows that the power transmission distance is an important influence factor of the life cycle cost of the three power transmission modes. The invention takes an offshore wind farm in south China as an example, and obtains the boundary condition and the corresponding critical length when the superconducting direct current cable is applied to an offshore wind farm by comparing the life cycle cost of three power transmission modes.

(1) Offshore wind farm and associated cost parameters

The total capacity of the offshore wind power station is 600 MW. Superconducting direct current cable miningWith bipolar supply, rated capacity P_H600MW rated voltage U_H35kV, 2 for loop number n, rated current I_H4.3kA, 2I for each cable to satisfy the N-1 principle_H8.6 kA; the HVAC transmission mode selects four-loop 220kV three-core XLPE submarine cable, the submarine cable structure type is HYJQ41-F127/220kV +24C photoelectric composite cable, the conductor sectional area is 3 multiplied by 500mm^2[52]Rated current of cable I_HA492A; the HVDC power transmission mode adopts bipolar power supply, and three-circuit 200kV direct current HYJQ41-F +/-200 kV +24C photoelectric composite cables are selected; the cross-sectional area of the conductor is 500mm²Rated current of cable I_HD＝500A。

Other required parameters: superconducting direct current cable reference unit price X _HTS1400 rLm; the reference unit price of the refrigerator is r-4900; HVAC Cable Purchase price of X_HVAC606.5 ═ m; HVDC Cable purchase price is X_HVDC335.6 ═ m; the superconducting cable has a laying cost of A_{HTS installation of unit length}350 ═ m; HVAC Cabling cost is taken as A_{HVAC installation per unit length}1000 ═ m; HVDC cable laying cost is taken from A_{HVDC laying per unit length}800 ═ m; the unit capacity reactive compensation cost is A_{Unit reactive compensation cost}5.33W/MVar; construction cost A of unit capacity AC transformer substation_{Cost of AC substation}30.29W/MVA; construction cost A of unit capacity high-voltage direct-current converter station_{Cost of high voltage direct current converter station}＝140W￥/MVA。

(2) Lifecycle cost comparison for different power transmission modes

1) Life cycle cost comparison of superconducting DC cable and HVAC cable transmission modes

By combining the data and the calculation method provided in the foregoing, the life cycle costs of the two power transmission modes can be respectively found and compared:

A_HTS＝A_HVAC*R

wherein R is the ratio of the rated power transmitted by the superconducting direct current cable and the HVAC cable, and R is 1 for the same wind power plant.

Substituting into a life cycle cost calculation formula to obtain the life cycle cost of the superconducting direct current cable lower than the critical length of the HVAC, wherein the calculation formula is as follows:

the important influencing factors are as follows: the system comprises an electric power meter, a wind power station, a generator, a wind power station, a generator.

At present, the purchase unit price of the superconducting cable, the unit price of the refrigerating machine and the refrigerating efficiency of the refrigerating machine are higher, so that the purchase cost of the superconducting cable and the refrigerating machine is higher, and in addition, the construction cost of the direct current converter station is higher than that of a transformer substation, so that the four factors become main influence factors of the critical length.

And analyzing the boundary condition of the critical length, namely the denominator of the calculation formula is positive, and the condition that the life cycle cost of the superconducting cable is superior to that of the common alternating current cable exists only when the denominator is positive. The boundary conditions are shown below:

4*X_HVAC+4*A_{HVAC installation per unit length}+0.086εdP_{HVAC unit line loss}*μ-8*X_HTS*I_H-4*A_{HTS unit length laying}-(0.086*ε*ρ*d+r)*(P_{Dewar pipe}+P_{Dewar pipe joint}+P_{Flow of liquid nitrogen})＞0

Taking 0.7 Rc/kW.h as the related condition epsilon of the current superconducting cable, taking 14.3 as d when the superconducting cable has an operation life of 40 years, taking 19 as rho, and taking other parameters as described above. Under this parameter condition, the denominator is calculated negative and there is no advantage of the superconducting cable over the conventional HVAC cable.

Under the prior art conditions, the critical length of the superconducting cable superior to the common HVAC cable does not exist due to the factors of low purchase cost of the superconducting cable, low purchase cost of the refrigerator, low efficiency of the refrigerator, low system load rate and the like. However, with the development of the technology in the future, after the cost is further reduced, the critical length boundary condition of the superconducting cable applied to the wind power plant compared with the common HVAC cable can be met, the critical length is gradually shortened, and the superconducting direct current transmission technology is expected to be widely applied.

Substituting the relevant fixed cost parameters into a life cycle cost calculation formula, neglecting the part with more than three orders of magnitude difference, and obtaining the life cycle cost (unit: element) of the superconducting cable as follows:

A_HTS＝(34.4*X_HTS+1400+4.24*r+4.91*ρ)*l+(459*u+40)*r+944.49M+8M*μ

the HVAC cable lifecycle cost can be derived by the same token as:

A_HVAC＝(7236.16+128.69*μ)*l+502.634M

the boundary condition at this time is

5836.16+128.69*μ-34.4*X_HTS-4.91*ρ-4.24*r＞0

When the system load rate, the superconducting cable unit price, the refrigerating machine refrigeration coefficient and the refrigerating machine unit price meet the boundary conditions, the critical length exists that the superconducting direct current cable grid-connected cost is lower than the HVAC grid-connected cost.

2) The life cycle cost of superconducting direct current cables is compared with that of HVDC cables.

By combining the data and the calculation method provided by the foregoing, the life cycle costs of the two power supply modes can be respectively obtained and compared:

A_HTS＝A_HVDC*R

wherein R is the ratio of the rated power transmitted by the superconducting direct current cable and the HVDC cable, and R is 1 for the same wind power plant.

Substituting the life cycle cost calculation formula into the life cycle cost calculation formula to obtain the life cycle cost of the superconducting direct current cable lower than the critical length of the HVDC, wherein the calculation formula is as follows:

Similar to a common HVAC cable, four factors, namely purchase price of a superconducting cable, purchase price of a refrigerator, refrigeration efficiency of the refrigerator and construction cost of a direct current converter station, are main influence factors of critical length. The boundary conditions are shown below:

6*X_HVDC+6*A_{HVDC laying per unit length}+0.086εdP_{HVDC Unit line loss}*μ-8*X_HTS*I_H-4*A_{HTS unit length laying}-(0.086*ε*ρ*d+r)*(P_{Dewar pipe}+P_{Dewar pipe joint}+P_{Flow of liquid nitrogen})＝0

Under the current conditions: ε was 0.7 kW.h, d was 14.3 and ρ was 19, all other parameters were as described above, with an operating life of 40 years.

Under the condition of the parameters, the life cycle cost variation rule of the two power transmission modes is opposite to that of the HVAC power transmission mode, when the power transmission distance is less than the critical length, the economy of the HTS cable is better, and when the power transmission distance is greater than the critical length, the HVDC cable is superior in the economic aspect. Similar to the above HVAC calculations, substituting the relevant parameters, one can obtain the HVDC cable life cycle cost (unit: yuan) as:

A_HVDC＝(6814+64.195*μ)*l+138.71M*μ+1849.34M

the boundary conditions at this time are:

5414+64.195*μ-34.4*X_HTS-4.91*ρ-4.24*r＝0

when the system load factor, the superconducting cable unit price, the refrigerating coefficient of the refrigerating machine and the refrigerating machine unit price meet the boundary conditions, the critical length exists when the superconducting direct current cable grid-connected cost is lower than the HVDC grid-connected cost.

(3) Life cycle cost analysis of different power transmission modes

In a superconducting cable unit price X _HTS1400 rRm, the unit price of the refrigerator is 4900 Rm, the performance coefficient of the refrigerator is ρ 19, and the load factor μ is 0.5 (average output of offshore wind farm), under the existing production parameter conditions, the 40-year life cycle cost (cost unit: yuan) (transmission distance unit: meter) of the three cables is:

A_HTS＝70429.3*l+949.81M

A_HVAC＝7300.5*l+502.634M

A_HVDC＝6878.2*l+1918.7M

for the offshore wind power plant with the capacity of 600MW, three grid-connected schemes are assumed to be respectively:

1) HTS: two loops of 600MW superconducting direct current cable bipolar power transmission with rated voltage of 35 kV.

2) HVAC: and four-circuit 200MW three-core XLPE alternating current cable with rated voltage of 220kV is used for power transmission.

3) HVDC: and the two poles of the XLPE direct current cable with 300MW and 200kV rated voltage are supplied with power.

It can be seen that the HVDC power transmission cost per unit length is lower than the HVAC power transmission under the existing power transmission modes and parameters. Because the HVDC cable adopts a bipolar power supply mode, the number of required cables is large, the cable laying cost is high, and the cost advantage per unit length is not expected to be large.

The cost per unit length of the superconducting direct current transmission is far higher than that of the other two conventional power transmission modes due to the factors of higher cable purchase cost, higher refrigerator purchase cost, lower refrigerator efficiency and the like, and the situation that the economic aspect of the superconducting direct current transmission is superior to that of HVAC does not exist; compared with HVDC, superconducting DC transmission is superior only in the case of relatively low transmission distance, and the critical length is 15.25 km.

The superconducting direct current cable has the main advantages that the transmission loss is zero in an offshore wind power plant grid-connected scene, the operation loss of the superconducting direct current cable cannot be ignored due to the large heat loss of a superconducting refrigeration system, and the operation loss of the three power transmission modes is compared and analyzed in the section.

Under the parameter conditions that ρ is 19 and u is 1, the energy loss of each of the three transmission methods is:

P_HTS＝80.56W/m*l+6.96*10⁶W

P_HVAC＝111.3W/m*l

P_HVDC＝55.5W/m*l+15.6*10⁶W

the part of the above equation proportional to the transmission length l (unit: m) is mainly the cable run loss and the constant part independent of l is mainly the converter station loss.

It can be seen that under this parameter, the loss per unit length of the HVDC cable is the smallest, only 49.9% of that of the HVAC cable, but the loss per unit length of the HTS cable is now as high as 80.56W, which is much higher than the expected loss situation, because the refrigerator coefficient of performance ρ of 19, which is required to consume 19W of electrical energy per 1W of heat load removed by the refrigerator, is only 4.24W per unit length of heat load, and on the basis of the prior art, the actual coefficient of performance ρ ranges from 18 to 26, which means that the superconducting direct current transmission technique is not dominant even in terms of loss of electrical energy per unit length.

Only by reducing the performance coefficient of the refrigerating machine to 11.09, namely, by improving the efficiency of the refrigerating machine to about 27.3%, and reducing the heat load of the unit length of the superconducting direct current system, the superconducting direct current cable can be advantageous in the aspect of electric energy loss of the unit length, but the efficiency of the existing refrigerating machine is only 11.7% -19.8%.

Because the heat loss of the unit length of the superconducting direct current cable is irrelevant to the load rate, if the load rate of the wind power plant is reduced due to output fluctuation, the superconducting direct current cable is less dominant at the moment. If the average output of the offshore wind farm is 50% (mu is 0.5), the efficiency of the refrigerator needs to be increased to about 54.6% to make the unit length loss of the superconducting direct current cable lower than that of the other two conventional transmission modes.

Under the current technical conditions, the grid-connected life cycle cost of the superconducting direct current cable for the offshore wind power plant is higher, and the superconducting direct current cable is not dominant in the economic aspect compared with HVDC and HVAC power transmission modes, which is caused by the factors of higher unit price of the superconducting direct current cable, overhigh heat loss of a refrigerating system, higher unit price of a refrigerating machine, unsatisfactory efficiency of the refrigerating machine and the like. The section provides an improvement scheme for a superconducting direct current cable power transmission system, so that the life cycle cost of superconducting direct current power transmission is reduced.

(1) The power transmission voltage is properly increased, so that the rated current of the cable is reduced.

Because the purchase cost of the superconducting direct current cable is in direct proportion to the current-carrying capacity, the power transmission voltage is improved, and the purchase cost of the superconducting direct current cable can be greatly reduced by reducing the rated current of the cable. When the superconductive direct current transmission voltage is increased to 150kV, the rated current of the cable is reduced to 1kA, and the required current-carrying capacity of the cable is reduced to 2 kA. However, this method may cause the construction and operation and maintenance costs of the superconducting dc converter station to increase.

(2) The rated capacity of a single cable is reduced, and the cost loss of redundant cables is reduced.

Reducing the capacity of a single cable reduces the purchase cost of redundant cables arranged to satisfy the N-1 principle. The rated capacity of a single cable is reduced to 300MW, three times of transmission are carried out, two improvement modes are considered together, at the moment, the rated current of the superconducting cable is reduced to 666.7A, and the current-carrying capacity required by the cable is reduced to 1 kA. However, this method results in increased cabling costs and increased cable heat loss.

(3) The unit price of the superconducting cable is reduced, the unit price of the refrigerator is reduced, and the refrigerating efficiency of the refrigerator is improved.

The critical lengths of the superconducting cable and the two transmission methods deduced in the foregoing show that reducing the purchase price of the refrigerator (about 500 rmb/W, which is predicted to be reduced to around this level after 5 years according to the industry), improving the efficiency of the refrigerator (to about 27% or more, and the superconducting direct current cable will be dominant in loss when the value is reached by the foregoing analysis) will contribute to the popularization of the superconducting cable in this scenario.

(4) The heat leakage of the superconducting cable refrigeration equipment is reduced.

The superconducting direct-current transmission heat insulation technology is improved, the unit length heat loss of the Dewar type pipe is reduced to 0.75W, the unit length heat loss of the Dewar type pipe is reduced to 2.67W/pipe, and meanwhile, the design that a single-return bipolar cable uses the same refrigeration pipeline is adopted. The improvement technology can reduce the heat loss per unit length of the single-loop superconducting direct current cable to 0.81W/m.

After the measures are comprehensively adopted, the superconducting direct current transmission life cycle cost when the load factor mu is 0.5 (the average output of the wind power plant is calculated according to 50% of the rated capacity) is as follows:

A_HTS＝(6*X_HTS+3406)*l+1457.2M

(1) in this case, the boundary condition obtained by comparison with the HVAC transmission system is X_HTS649.1 Rm, when the boundary condition is satisfied, the transmission distance is less than the critical length, the cost of HVAC cable is lower; the transmission distance is greater than that of the adjacentThe boundary length is long, and the cost of the HTS cable is low; HVAC cable costs are always lower than HTS cables when boundary conditions are not met. The superconducting dc cable versus HVAC transmission cost versus transmission distance is shown in fig. 2.

In the offshore wind farm grid-connected scene, the superconducting direct current cable is compared with the HVAC power transmission mode, and the applicable evaluation criterion of the superconducting direct current cable is given as shown in Table 1. When the conditions described in the table are met, the economics of superconducting dc cables will be better than normal HVAC cables.

TABLE 1 superconducting DC Transmission Life-cycle cost over HVAC boundary conditions and critical Length

(2) Compared with the HVDC transmission mode, the cost change rule of the HVDC and superconducting direct current transmission life cycle and the cost change rule of the HVAC and superconducting direct current transmission life cycle are just opposite when the improved conditions are met, and when the boundary condition X is met_HTSWhen the power transmission distance is more than or equal to 578.7 Rm/kA.m, the power transmission distance is less than the critical length, and the cost of the HTS cable is lower; the transmission distance is greater than the critical length, so that the HVDC cable has lower cost; HTS cables are always less costly than HVDC cables when boundary conditions are not met.

The main reasons for this difference are: compared with HVDC, superconducting direct current transmission has lower voltage grade, lower construction cost and operation and maintenance cost of a converter station, and the opposite is realized for HVAC. The relation between the transmission cost and the transmission distance of the superconducting direct current cable and the HVDC is shown in fig. 3.

In the offshore wind farm grid-connected scene, the superconducting direct current cable is compared with the HVDC power transmission mode, and the applicable evaluation criterion of the superconducting direct current cable is shown in table 2. When the conditions described in the table are met, the economy of the superconducting direct current cable is better than that of the HVDC cable, and particularly, when the related cost of the superconducting direct current cable is reduced, the cost of a superconducting direct current cable transmission mode under any length is better than that of an HVDC cable transmission mode due to factors such as low construction cost of a converter station and the like.

TABLE 2 boundary conditions and critical lengths for superconducting direct current transmission lifecycle cost superior to HVDC

(3) Analysis of economic impact of wind power plant capacity on different power transmission modes

In the previous calculation in this chapter, a 600MW offshore wind farm is taken as an example, if the capacity of the wind farm is increased to 1200MW, the voltage levels of three power transmission modes of superconducting direct current, HVAC and HVDC are unchanged, only the number of cable loops and the sectional area of a superconducting cable are increased, and the life cycle costs of the three power transmission modes are obtained by the calculation mode as above:

A_HTS＝(12*X_HTS+3406)*l+2914.4M

A_HVAC＝12849.9*l+975.22M

A_HVDC＝11433*l+3716.7M

at this time, the relationship between the life cycle cost, the transmission distance and the transmission capacity of the superconducting direct current cable and the HVAC cable is shown in fig. 4.

Comparing two power transmission modes of a superconducting direct current cable and an HVAC (heating, ventilation and air conditioning) to obtain the following result: the boundary condition for the existence of the applicable critical length of the superconducting cable is X_HTS787/kAm is less than or equal to. With X_HTSFor example, 500 rah/kA · m, the critical length of the superconducting dc cable transmission system is 563km, which is better than the HVAC system. And after comparing the two transmission modes of the superconducting direct current cable and the HVDC, the following results are obtained: the unit price boundary condition of the superconducting direct current cable is X_HTS≥668.9￥/kAm。

Therefore, with the increase of the capacity of the wind power plant, the application of the superconducting direct current transmission technology is more facilitated. The relation between the unit length heat loss of the superconducting direct current cable and the capacity and rated current of the cable is small, and the unit length transmission loss of the conventional power transmission mode is in positive correlation with the system capacity.

(4) Life cycle cost impact factor summary

The factors influencing the life cycle cost of the superconducting direct current cable transmission mode mainly comprise cable length, cable manufacturing cost, refrigerating machine efficiency, load rate, direct current converter station construction cost, electricity price, time period and the like, wherein the factors influencing the cost comparison result of the superconducting cable transmission mode and the HVAC and HVDC transmission modes are shown in table 3, wherein the arrow is upwards to indicate that the superconducting cable transmission mode is more beneficial, and the arrow is downwards to indicate that the superconducting cable transmission mode is more unfavorable.

TABLE 3 Life cycle cost influencing factors

According to the life cycle cost calculation model of applying the superconducting direct current cable to offshore wind power plant grid connection, boundary conditions and critical lengths of the superconducting direct current cable applied to offshore wind power plant grid connection scenes are obtained finally through cost comparison of different power transmission modes, and a calculation method of the boundary conditions and the critical lengths is obtained. When the offshore wind farm grid-connected scheme containing the superconducting direct current cable is selected, the critical length of the superconducting direct current cable with the predominant economy exists only when the boundary condition is met. When the critical length is met, the superconducting direct current cable can be selected as a grid-connected scheme of the offshore wind farm. The boundary conditions and the critical lengths provided by the invention are calculated under typical parameter conditions, relevant parameters will change along with the development of the superconducting direct current cable and the offshore wind power plant, and the boundary conditions and the critical lengths under different parameter conditions can be obtained by applying the calculation method provided by the invention.

The research content of the invention provides a relatively comprehensive quantification method for selecting the offshore wind power plant grid-connected mode in consideration of the superconducting direct current cable, and the method has a positive effect on promoting the practical application of the superconducting cable.

A second aspect.

Referring to fig. 5-6, an embodiment of the present invention provides a cable type selection system for an offshore wind farm, including:

a cable model selection model establishing module 10, configured to obtain related parameters of a superconducting direct current cable, related parameters of an HVDC cable, related parameters of an HVAC cable, related parameters of a refrigerator, and parameters of elements; and establishing a cable model selection model according to the related parameters of the superconducting direct current cable, the related parameters of the HVDC cable, the related parameters of the HVAC cable, the related parameters of the refrigerating machine and the element parameters.

the refrigerator-related parameters include: refrigerator performance parameters and refrigerator purchase price;

the cable length minimum model is:

A₁＝A_{construction of superconducting DC converter station}+A_{Operation and maintenance of superconducting direct current converter station}-A_{High-voltage AC transformer substation constructionIs provided with}-A_{Operation and maintenance of high-voltage alternating-current transformer substation}-A_{Reactive power compensation}；

Wherein l_minIs the minimum value of the cable length, A₁For the first cost, A_{Construction of superconducting DC converter station}Construction costs for superconducting direct current converter stations, A_{Operation and maintenance of superconducting direct current converter station}For the operation and maintenance costs of superconducting DC converter stations, A_{Construction of high-voltage AC transformer substation}For the construction costs of high-voltage AC substations, A_{High-voltage AC transformer substation operation and maintenance}For the operation and maintenance cost of high voltage AC transformer station, A_{Reactive compensation}For HVAC reactive compensation costs, P₁Is the first loss, rho is the refrigerator performance parameter, mu is the wind farm operating load factor, P_{Current lead}For current lead loss, P_{Joint resistor}For resistive losses of the joint, P_{Transition conductor}For excessive conductor loss, P_{Low-temperature container}For cryogenic vessel depletion, P_{Superconducting converter station losses}For superconducting DC converter station losses, P₂For the second loss, ε is the electricity price, d is the running time discount factor, r is the refrigerator purchase price, P_{Dewar pipe}Is a dewar pipe loss, P_{Dewar pipe joint}For a loss of a Dewar coupling, P_{Flow of liquid nitrogen}Is the flow loss of liquid nitrogen, k is the cost coefficient of pollution discharge, Q_HTSFor superconducting DC grid-connected system pollutant discharge, Q_HVACFor HVAC grid-tied system pollutant emissions, X_HVACPurchase price for HVAC Cable, A_{HVAC installation per unit length}For unit length of HVAC cabling cost, P_{HVAC unit line loss}For unit length of HVAC cable loss, I_HTSFor the rated current, X, of a superconducting DC cable_HTSPurchase price for superconducting DC cables, A_{HTS unit length laying}The laying cost of the unit length of the superconducting direct current cable is calculated;

the maximum model of the cable length is as follows:

Wherein l_maxAt maximum cable length, A₂For the second cost, A_{Construction of superconducting DC converter station}Construction costs for superconducting direct current converter stations, A_{Operation and maintenance of superconducting direct current converter station}For the operation and maintenance costs of superconducting DC converter stations, A_{Construction of high-voltage direct current converter station}For the construction costs of HVDC converter stations, A_{Operation and maintenance of high-voltage direct-current converter station}For the operation and maintenance cost of the high-voltage direct-current converter station, P₁Is the first loss, rho is the refrigerator performance parameter, mu is the wind farm operating load factor, P_{Current lead}For current lead loss, P_{Joint resistor}For resistive losses of the joint, P_{Transition conductor}For excessive conductor loss, P_{Low temperature container}For cryogenic vessel depletion, P_{Superconducting converter station losses}For superconducting DC converter station losses, P₂For the second loss, ε is the electricity price, d is the running time discount factor, r is the refrigerator purchase price, P_{Dewar pipe}For Dewar tube losses, P_{Dewar pipe joint}For a loss of a Dewar coupling, P_{Flow of liquid nitrogen}Is the flow loss of liquid nitrogen, k is the cost coefficient of pollution discharge, Q_HTSPollutant discharge amount Q for superconducting direct current grid-connected system_HVDCFor HVDC grid-connected system pollutant emissions, P_{High voltage direct current converter station loss}For losses in the HVDC converter station, X_HVDCIs HVDCPurchase price of cable, A_{HVDC laying per unit length}For unit length HVDC cable laying cost, P_{HVDC Unit line loss}For unit length of HVDC cable loss, I_HTSFor the rated current, X, of a superconducting DC cable_HTSPurchase price for superconducting DC cables, A_{HTS unit length laying}The cost is the unit length of the superconducting direct current cable.

Specifically, the method comprises the following steps:

The HVAC reactive compensation cost is calculated by the following formula:

Wherein, A_{Reactive power compensation}For HVAC reactive compensation costs, A_{Unit reactive compensation cost}Is the HVAC reactive compensation cost per unit length, and Q is the reactive compensation capacity required by the HVAC transmission system.

A_{construction of high-voltage alternating-current transformer substation}＝2*P_{HVAC Total Capacity}*A_{Cost of high voltage AC substation}；

Wherein A is_{Construction of high-voltage AC transformer substation}For the construction cost of high-voltage AC substations, P_{HVAC Total Capacity}For total capacity of high-voltage AC transmission, A_{High voltage ac substation cost}The cost of the high-voltage alternating-current transformer substation is low.

A_{operation and maintenance of high-voltage alternating-current transformer substation}＝m*(2*k_{Operation and maintenance}*P_{HVDC Total Capacity}+2*A_{High voltage AC substation communication}+2*A_{High voltage ac substation operation})；

The cable model selection result output module 20 is used for acquiring the length of a cable to be laid of the offshore wind farm; inputting the length of the cable to be laid into the cable model selection model, and outputting a cable model selection result;

in a specific embodiment, the cable type selection result output module 20 includes a cable length determining submodule 21, configured to:

judging the size relation between the length of the cable to be laid and the minimum value of the length of the cable; if the length of the cable to be laid is smaller than the minimum length of the cable, the output cable is an HVAC cable in the type selection result; if the length of the cable to be laid is larger than the minimum value of the length of the cable, judging the size relation between the length of the cable to be laid and the maximum value of the length of the cable; if the length of the cable to be laid is greater than the maximum length of the cable, the output cable is an HVDC cable; and if the length of the cable to be laid is not less than the minimum length of the cable and not more than the maximum length of the cable, the output cable is the superconducting direct current cable according to the model selection result.

In a third aspect.

The present invention provides an electronic device, including:

a processor, a memory, and a bus;

the bus is used for connecting the processor and the memory;

the memory is used for storing operation instructions;

the processor is configured to call the operation instruction, and the executable instruction enables the processor to perform an operation corresponding to the cable type selection method for the offshore wind farm shown in the first aspect of the present application.

In an alternative embodiment, an electronic device is provided, as shown in fig. 7, the electronic device 5000 shown in fig. 7 includes: a processor 5001 and a memory 5003. The processor 5001 and the memory 5003 are coupled, such as via a bus 5002. Optionally, the electronic device 5000 may also include a transceiver 5004. It should be noted that the transceiver 5004 is not limited to one in practical application, and the structure of the electronic device 5000 is not limited to the embodiment of the present application.

The processor 5001 may be a CPU, general purpose processor, DSP, ASIC, FPGA or other programmable logic device, transistor logic device, hardware component, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure. The processor 5001 may also be a combination of processors implementing computing functionality, e.g., a combination comprising one or more microprocessors, a combination of DSPs and microprocessors, or the like.

Bus 5002 can include a path that conveys information between the aforementioned components. The bus 5002 may be a PCI bus or EISA bus, etc. The bus 5002 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 7, but this is not intended to represent only one bus or type of bus.

The memory 5003 may be, but is not limited to, a ROM or other type of static storage device that can store static information and instructions, a RAM or other type of dynamic storage device that can store information and instructions, an EEPROM, a CD-ROM or other optical disk storage, optical disk storage (including compact disk, laser disk, optical disk, digital versatile disk, blu-ray disk, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.

The memory 5003 is used for storing application program codes for executing the present solution, and the execution is controlled by the processor 5001. The processor 5001 is configured to execute application program code stored in the memory 5003 to implement aspects illustrated in any of the method embodiments described previously.

Among them, electronic devices include but are not limited to: mobile terminals such as mobile phones, notebook computers, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and the like, and fixed terminals such as digital TVs, desktop computers, and the like.

A fourth aspect.

The present invention provides a computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements a method for cable typing for an offshore wind farm as set forth in the first aspect of the present application.

Yet another embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored, which, when run on a computer, enables the computer to perform the corresponding content in the aforementioned method embodiments.

Claims

1. A cable type selection method for an offshore wind farm is characterized by comprising the following steps:

acquiring the length of a cable to be laid of an offshore wind farm; inputting the length of the cable to be laid into the cable model selection model, and outputting a cable model selection result;

wherein, the related parameters of the superconducting direct current cable comprise: the method comprises the following steps of (1) construction cost of the superconducting direct current converter station, operation and maintenance cost of the superconducting direct current converter station, loss of the superconducting direct current converter station, pollutant discharge amount of a superconducting direct current grid-connected system, rated current of a superconducting direct current cable, purchase price of the superconducting direct current cable and laying cost of the superconducting direct current cable in unit length;

the element parameters include: current lead loss, joint resistance loss, excess conductor loss, cryogenic vessel loss, dewar pipe joint loss, liquid nitrogen flow loss, wind farm operating load rate, electricity price, operating time discount factor, pollution discharge cost coefficient;

the cable model selection model comprises: a cable length minimum model and a cable length maximum model; wherein, the first and the second end of the pipe are connected with each other,

the cable length minimum model is:

Wherein the content of the first and second substances,l_minis the minimum value of the cable length, A₁For the first cost, A_{Construction of superconducting DC converter station}Construction costs for superconducting direct current converter stations, A_{Operation and maintenance of superconducting direct current converter station}For the operation and maintenance costs of superconducting DC converter stations, A_{Construction of high-voltage AC transformer substation}For the construction cost of high-voltage AC substations, A_{High-voltage AC transformer substation operation and maintenance}For the operation and maintenance cost of high voltage AC transformer station, A_{Reactive compensation}For HVAC reactive compensation costs, P₁Is the first loss, rho is the refrigerator performance parameter, mu is the wind farm operating load factor, P_{Current lead}For current lead loss, P_{Joint resistor}For resistive losses of the joint, P_{Transition conductor}For excessive conductor loss, P_{Low temperature container}For cryogenic vessel depletion, P_{Superconducting converter station losses}For superconducting DC converter station losses, P₂For the second loss, ε is the electricity price, d is the running time discount factor, r is the refrigerator purchase price, P_{Dewar pipe}For Dewar tube losses, P_{Dewar pipe joint}For a loss of a Dewar coupling, P_{Flow of liquid nitrogen}Is the flow loss of liquid nitrogen, k is the cost coefficient of pollution discharge, Q_HTSFor superconducting DC grid-connected system pollutant discharge, Q_HVACFor HVAC grid-tied system pollutant emissions, X_HVACPurchase price for HVAC Cable, A_{HVAC installation per unit length}For unit length of HVAC cabling cost, P_{HVAC unit line loss}For unit length of HVAC cable loss, I_HTSFor the rated current, X, of a superconducting DC cable_HTSPurchase price for superconducting DC cables, A_{HTS unit length laying}The laying cost of the superconducting direct current cable is unit length;

the maximum model of the cable length is as follows:

P₁＝ρ[μ(P_{Current lead}+P_{Joint resistor}+P_{Transition conductor})+P_{Low-temperature container}]+2μP_{Superconducting converter station losses}；

Wherein l_maxAt maximum cable length, A₂For the second cost, A_{Construction of superconducting DC converter station}Construction costs for superconducting direct current converter stations, A_{Operation and maintenance of superconducting direct current converter station}For the operation and maintenance costs of superconducting DC converter stations, A_{Construction of high-voltage direct current converter station}For the construction costs of the HVDC converter station, A_{Operation and maintenance of high-voltage direct current converter station}For the operation and maintenance cost of the high-voltage direct-current converter station, P₁Is the first loss, rho is the refrigerator performance parameter, mu is the wind farm operating load factor, P_{Current lead}For current lead loss, P_{Joint resistor}For resistive losses of the joint, P_{Transition conductor}For excessive conductor loss, P_{Low temperature container}For cryogenic vessel depletion, P_{Superconducting converter station losses}For superconducting DC converter station losses, P₂For the second loss, ε is the electricity price, d is the running time discount factor, r is the refrigerator purchase price, P_{Dewar pipe}For Dewar tube losses, P_{Dewar pipe joint}For a loss of a Dewar coupling, P_{Flow of liquid nitrogen}Is the flow loss of liquid nitrogen, k is the cost coefficient of pollution discharge, Q_HTSFor superconducting DC grid-connected system pollutant discharge, Q_HVDCFor HVDC grid-connected system pollutant emissions, P_{High voltage direct current converter station loss}For losses in the HVDC converter station, X_HVDCPurchase price for HVDC cables, A_{HVDC laying per unit length}For unit length HVDC cable laying cost, P_{HVDC Unit line loss}For unit length of HVDC cable loss, I_HTSRated current, X, for superconducting DC cables_HTSPurchase price for superconducting DC cables, A_{HTS unit length lay-up}The laying cost of the unit length of the superconducting direct current cable is calculated;

the inputting the length of the cable to be laid into the cable model selection model and outputting a cable model selection result comprise:

2. The cable model selection method for offshore wind farms according to claim 1, wherein the construction cost of the superconducting direct current converter station is calculated by the following formula:

A_{construction of superconducting direct current converter station}＝2*P_{HTS Total Capacity}*A_{Cost of superconducting DC converter station}；

3. The cable model selection method for the offshore wind farm according to claim 1, wherein the operation and maintenance cost of the superconducting direct current converter station is calculated by the following formula:

Wherein A is_{Operation and maintenance of superconducting direct current converter station}M is annual capital value coefficient, k is the operation and maintenance cost of the superconducting direct current converter station_{Operation and maintenance}For maintenance rates of operation, A_{Construction of superconducting DC converter station}For construction of superconducting DC converter stationsAnd (4) cost.

4. The cable sizing method for offshore wind farms according to claim 1, wherein the HVAC reactive compensation cost is calculated by the formula:

5. The cable type selection method for the offshore wind farm according to claim 1, wherein the construction cost of the high-voltage alternating-current substation is calculated by the following formula:

Wherein, A_{Construction of high-voltage alternating-current transformer substation}For the construction cost of high-voltage AC substations, P_{HVAC Total Capacity}For the total capacity of the high-voltage AC transmission, A_{Cost of high voltage AC substation}The cost of the high-voltage alternating-current transformer substation is low.

6. The cable type selection method for the offshore wind farm according to claim 1, wherein the operation and maintenance cost of the high-voltage alternating-current substation is calculated by the following formula:

Wherein A is_{Operation and maintenance of AC transformer substation}For the operation and maintenance cost of the high-voltage AC transformer station, m is the annual fund present value coefficient, k_{Operation and maintenance}For maintenance of the operation, P_{HVDC Total Capacity}For the total capacity of HVDC transmission, A_{High voltage AC substation communication}For the maintenance cost of the communication equipment of the high-voltage direct-current transformer substation, A_{High voltage ac substation operation}For high-voltage direct-current transformer substationThe cost of operation.

7. A cable model selection system of an offshore wind farm, comprising:

the HVDC cable related parameters include: the method comprises the following steps of high-voltage direct current converter station construction cost, high-voltage direct current converter station operation and maintenance cost, HVDC grid-connected system pollutant emission, HVDC cable purchase price, unit length HVDC cable laying cost, unit length HVDC cable loss and high-voltage direct current converter station loss;

the cable model selection model comprises: a cable length minimum model and a cable length maximum model; wherein the content of the first and second substances,

the cable length minimum model is:

Wherein l_minIs the minimum value of the cable length, A₁For the first cost, A_{Construction of superconducting DC converter station}Construction costs for superconducting direct current converter stations, A_{Operation and maintenance of superconducting direct current converter station}For the operation and maintenance costs of superconducting DC converter stations, A_{Construction of high-voltage AC transformer substation}For the construction cost of high-voltage AC substations, A_{High-voltage AC transformer substation operation and maintenance}For the operation and maintenance cost of high voltage AC transformer station, A_{Reactive power compensation}For HVAC reactive compensation costs, P₁Is the first loss, rho is the refrigerator performance parameter, mu is the wind farm operating load factor, P_{Current lead}For current lead loss, P_{Joint resistor}For resistive losses of the joint, P_{Transition conductor}For excessive conductor loss, P_{Low temperature container}For cryogenic vessel depletion, P_{Superconducting converter station losses}For superconducting DC converter station losses, P₂For the second loss, ε is the electricity price, d is the running time discount factor, r is the refrigerator purchase price, P_{Dewar pipe}Is a dewar pipe loss，P_{Dewar pipe joint}For a loss of a Dewar coupling, P_{Flow of liquid nitrogen}Is the flow loss of liquid nitrogen, k is the pollution discharge cost coefficient, Q_HTSFor superconducting DC grid-connected system pollutant discharge, Q_HVACFor HVAC grid-tied system pollutant emissions, X_HVACPurchase price for HVAC Cable, A_{HVAC installation per unit length}For unit length of HVAC cabling cost, P_{HVAC unit line loss}HVAC Cable loss per unit length, I_HTSFor the rated current, X, of a superconducting DC cable_HTSPurchase price for superconducting DC cables, A_{HTS unit length laying}The laying cost of the unit length of the superconducting direct current cable is calculated;

the maximum model of the cable length is as follows:

Wherein l_maxAt maximum cable length, A₂For the second cost, A_{Construction of superconducting direct current converter station}Construction costs for superconducting direct current converter stations, A_{Operation and maintenance of superconducting direct current converter station}For the operation and maintenance costs of superconducting DC converter stations, A_{Construction of high-voltage direct current converter station}For the construction costs of the HVDC converter station, A_{Operation and maintenance of high-voltage direct-current converter station}For the operation and maintenance cost of the high-voltage direct-current converter station, P₁Is the first loss, rho is the refrigerator performance parameter, mu is the wind farm operating load factor, P_{Current lead}For current lead loss, P_{Joint resistor}To connect electricallyResistance loss, P_{Transition conductor}For excessive conductor loss, P_{Low temperature container}For cryogenic vessel depletion, P_{Superconducting converter station losses}For superconducting DC converter station losses, P₂For the second loss, ε is the electricity price, d is the running time discount factor, r is the refrigerator purchase price, P_{Dewar pipe}For Dewar tube losses, P_{Dewar pipe joint}For a loss of a Dewar coupling, P_{Flow of liquid nitrogen}Is the flow loss of liquid nitrogen, k is the cost coefficient of pollution discharge, Q_HTSFor superconducting DC grid-connected system pollutant discharge, Q_HVDCFor HVDC grid-connected system pollutant emissions, P_{High voltage direct current converter station loss}For losses in the HVDC converter station, X_HVDCPurchase price for HVDC cables, A_{HVDC laying per unit length}For unit length HVDC cable laying cost, P_{HVDC Unit line loss}For unit length of HVDC cable loss, I_HTSFor the rated current, X, of a superconducting DC cable_HTSPurchase price for superconducting DC cables, A_{HTS unit length laying}The laying cost of the unit length of the superconducting direct current cable is calculated;

the cable type selection result output module comprises a cable length judgment submodule for: