CN114202186A - Economic assessment method for offshore wind farm grid-connected conveying system - Google Patents
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Abstract
The invention relates to the field of power grid planning, and provides an economic assessment method for an offshore wind farm grid-connected conveying system, which comprises the following steps: s1, obtaining the installed capacity P and offshore transmission distance D of the wind power plant planned to be built, sending the installed capacity P and offshore transmission distance D to a static model to obtain a preset construction scheme and calculating the total static cost of one-time investment; and S2, converting the total static cost of the one-time investment by using a full-period equal-year-number algorithm, solving the dynamic economic cost according to a preset dynamic cost calculation method, and accumulating the total static cost of the one-time investment to obtain the total equal-year-number sum of the comprehensive static and dynamic costs. And S3, evaluating the preference transmission system technical scheme of the offshore wind power system under the input condition based on the obtained cost values of each economic measurement and calculation system scheme, and determining the optimal construction scheme under the close-range and long-range modes according to preference selection.
Description
Technical Field
The invention relates to the technical economy analysis field of an offshore wind farm collecting and conveying system, in particular to an economic assessment method for an offshore wind farm grid-connected conveying system.
Background
With the increasing demand for electric power resources and the gradual deterioration of global ecological environment, the proportion of green energy in power generation is further expanding in various countries in the world. Offshore wind power is one of renewable green energy, and is distinguished in various new energy power generation modes due to the characteristics of abundant resources and relatively stable output. In 2020, the global wind power total installed capacity reaches 96GW despite being influenced by global new crown epidemic situation. With the acceleration of global energy transformation speed and the reduction of new energy cost, the countries with abundant offshore wind resources pay more attention to the development of offshore wind power and give definite development and positioning. In order to achieve the goal that non-fossil energy accounts for 15% and 20% of primary energy consumption in 2020 and 2030, China pays high attention to the development of clean energy.
At the present stage, a plurality of innovative technologies and optimized configuration schemes are adopted in an onshore wind power generation system, and onshore wind power and high-voltage power transmission technologies are gradually migrating to a gigawatt-level deep sea large-scale wind power plant. Due to the fact that the transmission technology is limited, adaptability of a system grid-connected scene is different, and complex cost calculation brings new challenges for system planning, the existing structure is configured and optimized in combination with a new technology, and the realization of economic benefit maximization becomes a key point of large-scale offshore wind farm research. Therefore, it is very necessary to analyze the technical and economic aspects of the collective delivery system.
The minimized investment and operation cost can be realized by configuring a topological structure of a current collection system and reasonably planning a power transmission scheme of a conveying system, so that the power generation income and the transmission efficiency are maximized, and the economic benefit is improved. In the method, economic optimization is performed from the perspective of a system power transmission scheme, and the problems of power generation efficiency, engineering technical limitations of offshore construction and the like need to be considered simultaneously by combining the topological characteristics of a current collection system and the applicability of migration of an onshore power transmission system to an offshore power transmission system. In general, calculating the economic cost of the offshore wind farm by combining the characteristics of the offshore wind farm is an important reference for engineering construction. Therefore, it is important to establish an offshore wind farm grid-connected transmission economy evaluation model considering the line transmission capacity limit.
Disclosure of Invention
The invention aims to provide an economic assessment method for an offshore wind power plant grid-connected transmission system, which is used for designing an offshore wind power plant grid-connected transmission economic assessment model considering line transmission capacity limitation aiming at different gathering transmission system preference schemes by combining offshore wind power networking and power transmission technical trends.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows: an economic assessment method for an offshore wind farm grid-connected conveying system comprises the following steps:
s1, converting the installed capacity P and the transmission distance D of the wind power plant into dimensions set by an evaluation model and inputting the dimensions into an optimization model by acquiring the installed capacity P and the offshore transmission distance D of the wind power plant planned to be constructed, obtaining a preset construction scheme and calculating the total static cost of one-time investment;
s2, converting the total static cost of the one-time investment by using a full-period equal-year-number algorithm, solving the dynamic economic cost according to a preset dynamic cost calculation method, and accumulating the total static cost of the one-time investment to obtain the total equal-year-number sum of the comprehensive static and dynamic costs; .
And S3, evaluating the preference transmission system technical scheme of the offshore wind power system under the input condition based on the obtained cost values of each economic measurement and calculation system scheme, and determining the optimal construction scheme under the close-range and long-range modes according to preference selection.
Preferably, the preset construction scheme comprises cost calculation setting of a fan and outlet supporting equipment thereof, cost calculation setting of a topological structure route in a collecting system, cost calculation setting of a transmitting end converter station, a frequency conversion station or a booster station and supporting equipment thereof of a conveying system, cost calculation setting of a submarine cable and reactive compensation equipment thereof in the conveying system, and cost calculation setting of a receiving end converter station, a frequency conversion station and supporting equipment thereof of a power grid of the conveying system.
Preferably, the limitation of installed capacity P and the limitation of offshore transmission distance D means that there are limit values for the input parameters of installed capacity P and offshore transmission distance D, that is, there are limit values for inputting maximum transmission capacity P corresponding to different transmission distances D based on the thermal stability limit and reactive compensation limit of the submarine cable under the current preset construction scheme.
Preferably, the dynamic cost calculation method includes dynamic operation and maintenance cost and dynamic loss cost.
Preferably, in S2, the total static cost per investment is converted into the total static cost per investment for each working year of the planned life cycle of the wind farm.
Preferably, in step S3, the optimal construction plan includes: calculating the total dynamic and static cost values of the preference scheme 1, calculating the total dynamic and static cost values of the preference scheme 2, calculating the total dynamic and static cost values of the preference scheme 3, and calculating the total dynamic and static cost values of the preference scheme n.
Preferably, in S3, the preference system technical solution includes the following systems: the system comprises an AC topology collection + AC transmission system, an AC topology collection + AC frequency division transmission system, an AC topology collection + DC transmission system and a DC topology collection + DC transmission system.
Preferably, in S3, the evaluation is mainly compared with the economic cost minimization as an index.
Preferably, in S3, the close-range mode refers to an existing technical solution of the preference transmission system, and the solution includes: the remote vision system comprises an AC topology convergence + AC transmission system, an AC topology convergence + AC frequency division transmission system and an AC topology convergence + DC transmission system, and the remote vision mode comprises a DC topology convergence + DC transmission system.
In conclusion, the beneficial effects of the invention are as follows:
1. and (3) considering the technical trend of the full direct current networking of the DC topology convergence and DC transmission system, calculating the comprehensive cost of the system, and performing comprehensive evaluation and analysis on the economy of the convergence and transmission system of the offshore wind farm as one of the preference transmission system schemes.
2. The method comprises the steps of considering factors such as space limitation of an offshore platform and the like, comprehensively considering transmission capacity and transmission distance limitation of the offshore platform, carrying out full-period static cost conversion on various transmission schemes including a DC topology convergence and DC transmission mode by adopting an equal-year-number method to obtain a total value of comprehensive investment cost under each scheme, and evaluating obtained results by taking the lowest economic cost as an index. The various transmission schemes include: the system comprises an AC topology convergence + AC transmission system, an AC topology convergence + AC frequency division transmission system and an AC topology convergence + DC transmission system.
Drawings
FIG. 1 is a system diagram of an economic assessment model of the present invention;
FIG. 2 is a schematic diagram of the offshore wind power collection and delivery system of the present invention incorporated into an AC power grid;
FIG. 3 is a schematic diagram of the offshore wind power collection and transportation system of the present invention incorporated into a DC power grid;
FIG. 4 is a comparison of cost distance curves for 4 schemes under AC networking in an embodiment of the present invention;
fig. 5 is a comparison of the cost distance curves of 4 schemes under dc grid connection in the embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to fig. 1 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 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.
Example 1:
an economic assessment method for an offshore wind farm grid-connected conveying system comprises the following steps:
s1, converting the installed capacity P and the transmission distance D of the wind power plant into dimensions set by an evaluation model and inputting the dimensions into an optimization model by acquiring the installed capacity P and the offshore transmission distance D of the wind power plant planned to be constructed, obtaining a preset construction scheme and calculating the total static cost of one-time investment;
s2, converting the total static cost of the one-time investment by using a full-period equal-year-number algorithm, solving the dynamic economic cost according to a preset dynamic cost calculation method, and accumulating the total static cost of the one-time investment to obtain the total equal-year-number sum of the comprehensive static and dynamic costs;
and S3, evaluating the preference transmission system technical scheme of the offshore wind power system under the input condition based on the obtained cost values of each economic measurement and calculation system scheme, and determining the optimal construction scheme under the close-range and long-range modes according to preference selection.
The main purpose of this embodiment 1 is to calculate a preset technical solution (construction solution) by using the installed capacity P and the offshore transmission distance D of the planned wind farm, calculate the cost of the preset solution by using each cost calculation method, evaluate each preset solution according to the construction preference transmission system technical solution, and further obtain an optimal construction solution in the short-range and long-range modes according to the locked preference or the calculation and comparison of multiple preferences, where the specific model building operation principle and the calculation method are described in detail in embodiment 2.
Example 2:
an offshore wind farm grid-connected transportation economy evaluation model considering line transmission capacity limitation comprises the following steps:
the working principle of the scheme is briefly described as follows:
s1, acquiring installed capacity P and offshore transmission distance D of the wind power plant planned to be built, and converting the input installed capacity P and offshore transmission distance D of the wind power plant into the dimension set by the economic evaluation type model of the offshore wind power plant grid-connected transmission system;
and S2, inputting the installed capacity P and offshore transmission distance D data of the wind power plant with the unified dimension into the constructed optimization model, and calculating the total static cost of the one-time investment according to a preset technical scheme under the consideration of the limit of the installed capacity P and the respective limit of the offshore transmission distance D.
S3, converting the total one-time investment static cost obtained by model solution by using a full-period equal-year-number algorithm, and solving to obtain dynamic economic cost according to a preset dynamic cost calculation method to obtain the total annual value of the comprehensive static and dynamic costs;
and S4, evaluating and comparing the input preference transmission system technical scheme of the offshore wind power system based on the obtained cost values of the economic measurement system schemes to obtain the preferred scheme and the cost value under the scheme in the near and distant view modes.
The evaluation system scheme shown in fig. 1 outlines how the economic analysis of the planning step of the offshore wind power system engineering construction affects the system structure. In the collecting and conveying process from an offshore wind turbine to a onshore grid-connected point/convertor station, the offshore wind power collecting system can be formed in two modes, namely a traditional alternating current topological structure and a direct current collecting system. The direct current collection topological structure is designed for a system in a distant view mode. The offshore wind power long-distance transmission system has 3 transmission modes, namely HVAC transmission, FFTS transmission and HVDC transmission. By combining the collection system and the long-distance transmission system reasonably, and considering different situations of merging the onshore AC power grid and the onshore DC power grid, 4 general system schemes can be obtained as shown in figures 2 and 3.
The preset transmission mode in the evaluation model of the invention comprises all specific schemes contained in 4 overall system schemes, and each scheme is different according to different specific equipment and cable types. Taking the example of being incorporated into an ac power grid, the current collection system of the first scheme (fig. 2(a)) adopts the idea of first performing primary voltage boosting and then collecting. The voltage at the outlet of the fan is about 0.69kV, the voltage is increased to the internal network voltage of 35kV by primary boosting, and then the internal network voltage is converged into an alternating current bus. The scheme I adopts an alternating current topological structure with high reliability and a relatively mature HVAC power transmission mode as a whole. Scheme two adopts the idea of frequency division power transmission on the basis of the scheme one power transmission scheme to improve the transmission distance, and circuit and equipment modification required in the frequency division power transmission mode is shown in fig. 2 (b). And both the third scheme (fig. 2(c)) and the fourth scheme (fig. 2(d)) adopt a transmission mode of the HVDC, wherein the fourth scheme adopts a full-direct-current networking and transmission system, a power collection system of the fourth scheme adopts a theoretical model of direct-current topology, and a direct-current fan is correspondingly used. The direct current topological structure adopts a two-stage boosting mode, the direct current topological structure is firstly boosted to medium voltage through a DC/DC converter in the direct current fan structure, and then concentrated boosting is carried out through a DC/DC converter of a subsequent transmission system. The scheme of the system is simple in structure, and the economic cost is intuitively relatively low.
The economic indexes of the large-scale offshore wind power generation system mainly refer to static investment cost and dynamic maintenance and loss cost of the power generation and transmission system. The specific cost calculation is mainly related to the transmission distance and the system capacity. Total cost of active system CtotalThe economics of the collective delivery system are evaluated at a minimum as an objective function:
Min Ctotal＝Cinv,dynamic+Cm+Cl,total
in the formula: ctotalFor the total cost in the full life cycle, CmAnd Cl,totalRespectively the dynamic maintenance cost and the dynamic loss total cost. The specific calculation is constrained by the thermal stability limit and the transmission distance limit of the transmission channel.
The thermally stable constraint may be expressed as
Wherein I is the current-carrying capacity of the conductor, thetamaxMaximum temperature allowed for the conductor, θaThe temperature is 25 ℃ generally; pdDielectric loss per unit length for conductor insulation material; g1,G2,G3,G4Thermal resistances between the conductor insulating layer and each medium between the armoring layers are respectively; n is the number of cable cores, lambda1And λ2The loss coefficients of the sheath and the armor are respectively; rACThe skin effect is considered in the calculation for the ac resistance of the conductor during operation.
The transmission distance constraint may be expressed as
x≤x0
In the formula, x0Indicating the distance transmission limits of systems of different limiting current carrying capacities. The transmission distance of the AC transmission system is increased, the charging power is increased, and the available effective transmission capacity is reduced, so that the transmission distance of different types of submarine cables in different capacity systems is constant, and the transmission distance can be calculated by a distribution parameter model of the line
In the formula of UeAnd IeRespectively a starting end voltage and a starting end current; x is the transmission distance, ZeIs the wave impedance. γ is the propagation coefficient. The reactive compensation equipment is arranged at the two ends or the single end of the submarine cable to improve the available transmission capacity value of the line,however, since the offshore platform has a limited area, the number of off-shore reactive power compensation equipment which can be installed is also limited and is limited by the current-carrying capacity of the cable. And the transmission limit and the capacity limit of different wires can be calculated by integrating the current-carrying capacity limit and the reactive compensation limit of the cable. Cable parameters and technical limits are shown in table 1.
TABLE 1 Cable parameters and technical Limit values
In the invention, according to the preset technical scheme in the model, based on the full-period static dynamic comprehensive cost calculation method, the economic evaluation is carried out on each technical scheme in the model, and the concrete solving steps are as follows:
solving static cost: the static investment cost mainly comprises the purchase and installation cost of each basic structure of a fan, a transformer substation, a converter station and the like of the terminal, and the route cost of cable laying and the like in the power transmission system. The main factors considered for the solution include:
(1) fan cost. Cost for fan acquisition Cinv,windAnd selecting an alternating current fan with a PMSG structure, wherein the installation cost is related to the installed capacity, and the installation cost comprises the purchase, transportation and installation costs of the structures such as a unit, blades, a tower and the like of the fan. The specific calculation method comprises the following steps:
Cinv,wind＝Cwind turbineP
in the formula, Cwind turbineThe price of the fan is ten thousand yuan/MW, and P is installed capacity and MW. Because the frequency division transmission mode redesigns the frequency, the fan cost under the frequency division transmission mode is different from the fan cost under other power transmission modes. Considering that the frequency division power transmission mode needs to reset the frequency of the fan, the volume of the improved fan is increased, but the structure is simplified, and the production process is relatively simple, so that the installation cost in the frequency division power transmission mode is calculated according to 94% of the cost of the power frequency fan. Thus the investment cost C of the wind power plantinv,wind(ten thousand yuan):
Cinv,wind＝94％Cwind turbineP
(2) transformer substation, converter station cost. The transformer substation and the converter station of the large-scale offshore wind power system are mainly and intensively built on an offshore platform, and for the alternating current system, the main cost of the offshore platform is formed by the construction cost of a collection transformer substation and reactive compensation equipment. Offshore platform substation cost Cinv,subThe calculation formula of (ten thousand yuan) is as follows:
in the formula, β 1 and β 2 are respectively cost coefficients under different power transmission modes, the construction cost of the substation in the frequency division power transmission mode is higher than the power frequency, and the cost of the frequency division power transmission substation is conservatively estimated to be 1.5 times of the cost of the power frequency power transmission substation.
For a direct current system, the main cost of an offshore platform is the construction of a converter station, and whether the cost of a boosting transformer substation needs to be calculated depends on the type of a fan and a specific topological structure adopted when a unit is connected. If a topological mode of a direct current fan and a series structure or a parallel series structure is adopted, the voltage is directly increased to a transmission voltage level through a collection bus, and a transformer substation does not need to be installed on an offshore platform; if an alternating current fan or other topological structures are adopted, besides the converter station, a transformer substation with larger capacity still needs to be installed, and the voltage level required by a transmission system is increased. The calculation is performed by adopting a parallel-series type or a series type according to the topological structure of the current collection system, and if the condition that the direct-current voltage reaches the transmission condition can be met, the transformer substation is not considered at all, and only the converter station is considered. In addition, for an ac system, it is necessary to install reactive power compensation equipment, the calculation cost of which is
Cinv,VAR＝Q×pVAR
In the formula, Q is the reactive power value that the system needs to compensate, and is expressed in MVAR, and a typical reactive compensation value is shown in table 2. PVAR is the price per unit MVAR for installing reactive equipment.
TABLE 2 charging power and reactive compensation values for high voltage lines
(3) The cost of the cable. The cable cost refers to the purchase, transportation, laying and installation cost of the cable, the larger the capacity of the system is, the larger the current-carrying capacity requirement of the required cable is, and even two-loop or multi-loop lines are used for transmission, so that the capacity transmission upper limit is provided. For ac systems, the transmission distance is limited by the reactive limit value to be compensated, with an upper distance transmission limit. Therefore, the alternating current and direct current systems with different scales have different cable models and different quantities, and the cable cost difference is large. The calculation formula is as follows:
Cinv,cable＝ncCcabled
in the formula, ncIs the number of cables, CcableThe unit price of the cable is ten thousand yuan/km, and d is the transmission distance.
Solving dynamic cost: the dynamic cost mainly refers to the operation and maintenance cost and the loss cost after the fan system is put into operation formally. Because the basic structures of the alternating current system and the direct current system are different from the composition of the offshore platform, the operation and maintenance costs are different. For the alternating current system, the investment construction cost of the frequency division transformer substation in the frequency division transmission mode is conservatively estimated to be 1.5 times of the investment construction cost of the transformer substation in the power frequency transmission mode, and therefore the operation and maintenance cost of the frequency division transmission mode is calculated according to 1.5 times of the power frequency. The cost of losses in the transmission system, also called the running cost, is the economic loss of this part of the electrical energy which is less emitted during operation due to the loss of transformers, converters and cabling. The loss cost is often reflected by the transmission loss rate, which is one of the important indicators for measuring the economy of the power system.
Calculating the maintenance and loss cost of the whole wind power plant within the time range of the whole construction initial stage and the service life by using the total life cycle cost, replacing and depreciating the cost and the like:
in the formula, Cinv,staticIs the static total investment cost of the system, with the unit of ten thousand yuan per year, i is the discount rate, noAnd planning the operation years of operation. The dynamic costs include:
(1) maintenance costs. The maintenance cost mainly refers to the labor cost and the material cost for maintaining and overhauling basic structures such as equipment, cables and the like during the operation of the wind power plant. Because the basic structures of the alternating current system and the direct current system are different from the offshore platform, the selected cables are different, and the maintenance cost is different. To simplify the calculation, a maintenance rate m (%) of the system is defined to represent and calculate the maintenance cost.
Cm,AC＝m×P×Ttotal×pgrid
In the formula, TtotalFor the annual generation hours, P, of the wind farm operationgridThe unit is ten thousand yuan/MWh.
(2) And (5) loss cost. Loss costs in a transmission system refer to economic losses due to the fraction of power that is less emitted during operation due to transformer, converter and cabling losses and losses that are not generated during blackout repairs. The invention defines the transmission loss rate lambda of the system to reflect the loss condition of the system, and the loss cost of each structure of the system is as follows:
Cl＝λ×Ttotal×pgrid
because plan to have a power failure to overhaul often selects the less period of fan power output among the year, consequently, the loss cost that the maintenance that has a power failure leads to considers fan unit power output coefficient alpha, has:
in the formula, TdownThe days of power failure are required for planned maintenance all the year.
The embodiment is about the situation that the total cost of the wind power plant with the installed capacity P of 800MW is changed along with the total transmission distance under 4 transmission schemes.The power price of the online fan is 610 yuan/MWh, the annual power generation hours are 3000 hours, the annual average maintenance time is 20 days, and the output coefficient of the fan during maintenance is 0.4. The current rate i is 5 percent, and the operation age n isoFor 20 years. And preferably selecting an optimal transmission system scheme.
The information of the voltage grade of power frequency transmission, the number of cable returns, the price and the like of each scheme can be obtained from the table 3, so that the model selection and the price reference of the fans and the cables of 4 schemes can be obtained as shown in the table 4. The cost and specific coefficient of each scheme transformer substation and converter station are shown in table 5.
TABLE 3 Cable parameters and distance, Capacity technical limits
TABLE 4 Fan and Cable cost calculation
| Scheme(s) | Fan model selection | Cost of blower fan ten thousand yuan | Cable model selection | Number of circuit loops | Cost per unit distance of cable/ten thousand yuan/km |
| A | AC fan | 1120000 | |
2 | 734 |
| II | AC fan | 1052800 | |
2 | 1500 |
| III | AC fan | 1120000 | |
1 | 1500 |
| Fourthly | DC fan | 1120000 | |
1 | 550 |
TABLE 5 System architecture cost calculation
Note:1represents the off-shore (offset) parameter,2representing the terrestrial (onshore) parameters.
The transmission loss ratios of the respective structures of the system are shown in table 6, and thus the system maintenance cost and the loss cost are calculated as shown in table 7.
TABLE 6 Transmission loss Rate for each configuration of the System
| Name of System architecture | Transmission loss ratio (%) |
| Wind turbine generator and corollary equipment thereof | 2.0 |
| Offshore substation | 0.5 |
| Marine rectification station | 0.8 |
| Land inversion station | 0.8 |
| Land frequency conversion station | 1.0 |
TABLE 7 maintenance cost and loss cost values
| System scheme | Maintenance cost/ten thousand yuan | Loss cost/ten thousand yuan |
| A | 30744 | 32143 |
| II | 30744 | 32161 |
| III | 26352 | 32172 |
| Fourthly | 21960 | 32139 |
From the above calculation, it can be derived that the variation curve of the annual cost value of the whole life cycle of the 800MW system with the transmission distance of the system ranging from 0 to 1200km is shown in fig. 4 when the 800MW system is incorporated into the land ac power grid. It can be concluded that the change in the annual cost value over the whole life cycle with the system transmission distance ranging from 0 to 1200km is shown in figure 5 for the case of incorporation into an onshore dc grid.
In addition, the installed capacity of 250MW of an existing wind farm and the transmission distance of 70km are taken as example input models, and the output results of the models, that is, the cost of merging into the ac power grid and the cost of merging into the dc power grid are shown in table 8.
TABLE 8250 MW/70km Total cost of System full cycle
Further, the preset technical scheme comprises the steps of calculating and setting the cost of a fan and outlet supporting equipment thereof, calculating and setting the cost of a topological structure route in a collecting system, calculating and setting the cost of a transmitting end converter station, a frequency conversion station or a booster station and supporting equipment thereof of a conveying system, calculating and setting the cost of a submarine cable and reactive compensation equipment thereof in the conveying system, and calculating and setting the cost of a receiving end converter station, a frequency conversion station and supporting equipment thereof of a power grid of the conveying system.
In summary, the robot service system suitable for medical beauty institutions with a large number of inquiry complaints and follow-up complaints is established through machine learning and big data algorithms, so that the manpower is saved for hospitals, better experience is provided for patients, and the robot service system is worthy of popularization.
Claims (9)
1. The economic assessment method for the offshore wind farm grid-connected conveying system is characterized by comprising the following steps of:
s1, converting the installed capacity P and the transmission distance D of the wind power plant into dimensions set by an evaluation model and sending the dimensions to the static model by acquiring the installed capacity P and the offshore transmission distance D of the wind power plant planned to be constructed, obtaining a preset construction scheme and calculating the total static cost of one-time investment;
s2, converting the total static cost of the one-time investment by using a full-period equal-year-number algorithm, solving the dynamic economic cost according to a preset dynamic cost calculation method, and accumulating the total static cost of the one-time investment to obtain the total equal-year-number sum of the comprehensive static and dynamic costs;
and S3, evaluating the preference transmission system technical scheme of the offshore wind power system under the input condition based on the obtained cost values of each economic measurement and calculation system scheme, and determining the optimal construction scheme under the close-range and long-range modes according to preference selection.
2. The economic evaluative method of the offshore wind farm grid-connected conveying system according to claim 1, wherein the preset construction scheme comprises cost calculation setting of fans and their outlet corollary equipment, cost calculation setting of topological structure routes in the collection system, cost calculation setting of a conveying system transmitting end converter station, a frequency conversion station or a booster station and its corollary equipment, cost calculation setting of a submarine cable and its reactive compensation equipment in the conveying system, and cost calculation setting of a conveying system grid receiving end converter station, a frequency conversion station and its corollary equipment.
3. The method for evaluating the economy of the offshore wind farm grid-connected transportation system according to claim 2, wherein the limitation of installed capacity P and the limitation of offshore transportation distance D mean that the input parameters of installed capacity P and offshore transportation distance D have limiting values, that is, the input parameters have limiting values of maximum transportation capacity P corresponding to different transportation distances D based on the thermal stability limit and reactive compensation limit of the submarine cable under the current preset construction scheme.
4. The method according to claim 3, wherein the dynamic cost calculation method comprises dynamic operation and maintenance cost and dynamic loss cost.
5. The method for economic evaluative of grid-connected offshore wind farm delivery system according to claim 3, wherein in step S2, the total static cost per investment is converted into each working year of the planned life cycle of the wind farm.
6. The method for evaluating the economy of the offshore wind farm grid-connected delivery system according to claim 3, wherein in step S3, the optimal construction scheme comprises: calculating the total dynamic and static cost values of the preference scheme 1, calculating the total dynamic and static cost values of the preference scheme 2, calculating the total dynamic and static cost values of the preference scheme 3, and calculating the total dynamic and static cost values of the preference scheme n.
7. The method according to claim 1, wherein in S3, the preference system technical solution includes the following systems: the system comprises an AC topology collection + AC transmission system, an AC topology collection + AC frequency division transmission system, an AC topology collection + DC transmission system and a DC topology collection + DC transmission system.
8. The method according to claim 7, wherein in step S3, the evaluation is mainly compared with the minimum economic cost.
9. The method according to claim 7, wherein in S3, the short-range mode refers to an existing technical solution of a preference transmission system, and the solution includes: the remote vision system comprises an AC topology convergence + AC transmission system, an AC topology convergence + AC frequency division transmission system and an AC topology convergence + DC transmission system, and the remote vision mode comprises a DC topology convergence + DC transmission system.
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| CN116051158A (en) * | 2022-12-12 | 2023-05-02 | 中广核风电有限公司 | Method and device for determining cost of offshore wind farm |
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| CN116051158A (en) * | 2022-12-12 | 2023-05-02 | 中广核风电有限公司 | Method and device for determining cost of offshore wind farm |
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