Analytic method for optimizing machine expansion capacity of hydropower station of water-wind-light multi-energy complementary system

Abstract

The invention discloses an analytic method for hydropower station expansion capacity optimization of a water-wind-light multi-energy complementary system, and the method comprises the following steps: constructing a hydropower expansion target function through a net present value formula; based on the relation between the annual average hydroelectric power generation and the hydroelectric power expansion capacity, constructing a hydroelectric power expansion function; analyzing a function relationship between the annual average electricity abandoning rate and the hydropower expansion capacity to obtain an electricity abandoning expansion function; on the basis of the function relation between the annual average hydroelectric generation and the hydropower expansion capacity and the function relation between the annual average electricity abandoning rate and the hydropower expansion capacity, a hydropower station expansion cost-benefit function is obtained in combination with the constructed hydropower expansion target function; and obtaining the optimal hydropower station expansion capacity based on the obtained hydropower station expansion cost-benefit function. According to the method, complicated simulation calculation is avoided by utilizing an analysis method of the historical reservoir dispatching data, and the relationship between the installed capacity of the hydropower station and the cost effectiveness and the relationship between the hydroelectric generation and the abandoned power are quantified.

Description

Technical Field

[0001] The present invention relates to the field of hydropower stations with a water-wind-solar multi-energy complementary system, and in particular to the field of capacity expansion optimization of hydropower stations, and specifically to an analytical method for optimizing capacity expansion of hydropower stations with a water-wind-solar multi-energy complementary system. Background Art

[0002] Clean renewable energy sources such as hydropower, wind power and solar power have become an effective way to cope with the energy crisis, reduce emissions and meet the challenges of climate change. Hydropower has the ability to regulate and store electricity, and is a beneficial supplement to wind power plants and photovoltaic power plants. The stable water-wind-solar multi-energy complementary system integrates photovoltaic and wind power generation with adjustable hydropower, which is a promising strategy for effectively integrating renewable energy. Power station capacity configuration is an important issue in the water-wind-solar multi-energy complementary system, and current research focuses on wind and solar power installation planning. With the increasing construction of wind power stations and photovoltaic power stations, research on the expansion of hydropower stations is very necessary.

[0003] At present, most of the research methods for hydropower station installed capacity planning are numerical methods, which require complex simulation calculations. Based on this, the present invention provides an analytical method for optimizing the expansion capacity of a hydropower station in a water-wind-solar multi-energy complementary system. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides an analytical method for optimizing the expansion capacity of a hydropower station in a water-wind-solar multi-energy complementary system. By determining the optimal expansion capacity of the hydropower station, a new approach is provided for capacity planning of hydropower stations under the water-wind-solar complementary system.

[0005] According to one aspect of the present invention, a method for analyzing the capacity expansion optimization of a hydropower station in a water-wind-solar multi-energy complementary system is provided, comprising the following steps:

[0006] The objective function of hydropower expansion is constructed through the net present value formula;

[0007] Based on the relationship between the average annual hydropower generation and the hydropower expansion capacity, a hydropower expansion function is constructed;

[0008] Analyze the functional relationship between the annual average power abandonment rate and the hydropower expansion capacity, and obtain the power abandonment expansion function;

[0009] Based on the functional relationship between the average annual hydropower generation and the hydropower expansion capacity, as well as the functional relationship between the average annual power abandonment rate and the hydropower expansion capacity, combined with the constructed hydropower expansion objective function, the cost-benefit function of hydropower station expansion is obtained;

[0010] Based on the obtained cost-benefit function of hydropower station expansion, the optimal hydropower station expansion capacity is obtained.

[0011] As a further technical solution, the constructed hydropower expansion objective function is based on the maximum net present value within the entire life cycle of the hydropower station. The functional relationship expression of the maximum net present value is as follows:

[0012]

[0013]

[0014] in, is the net present value; Expand the capacity of hydropower stations; is the total number of hours in the calculation period; and They are the average annual power generation and initial average annual power generation of the water-wind-solar hybrid system respectively; and They are the annual average wind-solar curtailment rate and the initial annual average wind-solar curtailment rate of the hydro-wind-solar hybrid system; is the average annual power generation of wind and solar power; For the on-grid electricity price; To maintain operating costs; is the initial investment cost; is the social discount rate; is the multi-year discount factor of the water-wind-solar complementary system; It is the maximum expansion capacity of the hydropower station.

[0015] As a further technical solution, the relationship between system power generation and hydropower-expansion function and the relationship between power abandonment rate and power abandonment-expansion function under different hydropower station expansion capacities are shown as follows:

[0016]

[0017]

[0018] in, It is the hydropower-expansion function; It is the power abandonment-capacity expansion function; and They are the average annual power generation and initial average annual power generation of the water-wind-solar hybrid system respectively; is the average annual power generation of wind and solar power; and They are the annual average wind-solar curtailment rate and the initial annual average wind-solar curtailment rate of the hydro-wind-solar hybrid system; is the function value when the hydropower expansion capacity is 0; is the function value when the hydropower expansion capacity is 0.

[0019] As a further technical solution, based on the hydropower expansion function, the functional relationship between the average annual hydropower generation and the hydropower expansion capacity is obtained as follows:

[0020]

[0021] in, It is the hydropower-expansion function; Expand the capacity of hydropower stations; , , and is the function coefficient; It is the maximum expansion capacity of the hydropower station; It is the maximum annual hydroelectric power generation.

[0022] As a further technical solution, based on the power abandonment expansion function, the functional relationship between the annual average power abandonment rate and the hydropower expansion capacity is obtained as follows:

[0023]

[0024] in, It is the power abandonment-capacity expansion function; and is the power abandonment function coefficient; and They are the expansion capacity and maximum expansion capacity of the hydropower station respectively.

[0025] As a further technical solution, based on the functional relationship between the average annual hydropower generation and the hydropower expansion capacity and the functional relationship between the average annual power abandonment rate and the hydropower expansion capacity, combined with the constructed hydropower expansion objective function, the cost-benefit function of the hydropower station expansion is obtained, and the relationship is as follows:

[0026]

[0027] in, is the net present value; is the multi-year discount factor of the water-wind-solar complementary system; For the on-grid electricity price; To maintain operating costs; Expand the capacity of hydropower stations; , and is the function coefficient; is the power abandonment function coefficient; is the average annual power generation of wind and solar power; It is the initial investment cost for the expansion of the hydropower station.

[0028] As a further technical solution, based on the obtained cost-benefit function of hydropower station expansion, the optimal hydropower station expansion capacity is obtained, including:

[0029]

[0030]

[0031] in, To expand the capacity of hydropower for the best results; is the net present value; Expand the capacity of hydropower stations; is the multi-year discount factor of the water-wind-solar complementary system; , and is the function coefficient; is the power abandonment function coefficient; For the on-grid electricity price; To maintain operating costs; is the average annual power generation of wind and solar power; is the initial investment cost.

[0032] According to one aspect of the present invention, there is provided an analytical system for optimizing the capacity expansion of a hydropower station in a water-wind-solar multi-energy complementary system, comprising:

[0033] The first main module: used to construct the hydropower expansion objective function through the net present value formula;

[0034] The second main module is used to construct a hydropower expansion function based on the relationship between the average annual hydropower generation and the hydropower expansion capacity;

[0035] The third main module is used to analyze the functional relationship between the annual average power abandonment rate and the hydropower expansion capacity, and obtain the power abandonment expansion function;

[0036] The fourth main module is used to obtain the cost-benefit function of hydropower station expansion based on the functional relationship between the average annual hydropower generation and the hydropower expansion capacity and the functional relationship between the average annual power abandonment rate and the hydropower expansion capacity, combined with the constructed hydropower expansion objective function;

[0037] The fifth main module is used to obtain the optimal hydropower station expansion capacity based on the obtained hydropower station expansion cost-benefit function.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention avoids complex simulation calculations by utilizing the analytical method of historical reservoir dispatching data, and quantifies the relationship between the installed capacity of a hydropower station and cost-effectiveness, hydropower generation and power abandonment. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction is given below to the drawings used in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 A flow chart of an analytical method for optimizing the capacity expansion of a hydropower station in a water-wind-solar multi-energy complementary system provided in an embodiment of the present invention.

[0041] Figure 2 A schematic diagram for comparing and verifying the analytical results and numerical results of the analytical method for optimizing the expansion capacity of a hydropower station in a water-wind-solar multi-energy complementary system provided in an embodiment of the present invention.

[0042] Figure 3 A schematic diagram of the optimal expansion capacity and net present value of the Ertan Hydropower Station according to the analytical method for optimizing the expansion capacity of a hydropower station in a water-wind-solar multi-energy complementary system provided in an embodiment of the present invention.

[0043] Figure 4 A schematic diagram of the system structure of an analytical method for optimizing the capacity expansion of a hydropower station in a water-wind-solar multi-energy complementary system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions, for example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to the steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0045] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In addition, the technical features in the various embodiments or single embodiments provided by the present invention are arbitrarily combined with each other to form a new technical solution. This combination is not restricted by the sequence of steps and / or the structural composition mode, but must be based on the ability of ordinary technicians in this field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that this combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0046] See also Figure 1-4 The embodiment of the present invention provides an analytical method for optimizing the expansion capacity of a hydropower station in a water-wind-solar multi-energy complementary system, comprising the following steps:

[0047] 1) Construct the objective function of hydropower expansion through the net present value formula;

[0048] Specifically, the hydropower expansion objective function constructed in step 1) is based on the maximum net present value of the hydropower station during its entire life cycle. The functional relationship expression of the maximum net present value is as follows:

[0049] (1)

[0050] (2)

[0051] in, is the net present value; Expand the capacity of hydropower stations; is the total number of hours in the calculation period; and They are the average annual power generation and initial average annual power generation of the water-wind-solar hybrid system respectively; and They are the annual average wind-solar curtailment rate and the initial annual average wind-solar curtailment rate of the hydro-wind-solar hybrid system; is the average annual power generation of wind and solar power; For the on-grid electricity price; To maintain operating costs; is the initial investment cost; is the social discount rate; is the multi-year discount factor of the water-wind-solar complementary system; It is the maximum expansion capacity of the hydropower station.

[0052] The functional relationships between the system power generation and power abandonment rate under different hydropower station expansion capacities and the hydropower-expansion function and the power abandonment-expansion function are as follows:

[0053] (3)

[0054] (4)

[0055] in, It is the hydropower-expansion function; It is the power abandonment-capacity expansion function; and They are the average annual power generation and initial average annual power generation of the water-wind-solar hybrid system respectively; is the average annual power generation of wind and solar power; and They are the annual average wind-solar curtailment rate and the initial annual average wind-solar curtailment rate of the hydro-wind-solar hybrid system; is the function value when the hydropower expansion capacity is 0; is the function value when the hydropower expansion capacity is 0.

[0056] 2) Based on the relationship between average annual hydropower generation and hydropower expansion capacity, a hydropower expansion function is constructed;

[0057] First, through the principle of diminishing marginal benefits, it can be seen that the average annual hydropower generation and the expansion capacity of the hydropower station are in a nonlinear relationship. If it is a cubic function before all water resources are used, after exceeding a certain installed capacity, the hydropower generation will no longer increase and will be a constant. The functional relationship is expressed by the following formula:

[0058] (5)

[0059] in, It is the hydropower-expansion function; Expand the capacity of hydropower stations; , , and is the function coefficient; It is the maximum expansion capacity of the hydropower station; It is the maximum annual hydroelectric power generation.

[0060] Based on the historical dispatching data of the hydropower station, the average annual hydropower generation under different hydropower expansion capacities can be obtained. The historical dispatching data of the hydropower station specifically includes reservoir outflow, power generation head and power generation flow. The calculation formula for the average annual hydropower generation is as follows:

[0061] (6)

[0062] (7)

[0063] in, is the average annual hydroelectric power generation; The water consumption for power generation before the expansion; , and The increased water consumption for power generation after the expansion; is the comprehensive efficiency coefficient; for The actual operating power generation head during the period; is the total number of hours in the calculation period; To calculate the time period; for Reservoir outflow during the period; is the maximum current.

[0064] 3) Analyze the functional relationship between the annual average power abandonment rate and the hydropower expansion capacity, and obtain the power abandonment expansion function;

[0065] With the increase of hydropower installed capacity and transmission capacity, the wind and solar power absorption capacity has increased. Based on this assumption, the wind and solar power abandonment rate and the hydropower station expansion capacity are in a monotonically decreasing linear relationship. The functional relationship between the hydropower expansion capacity and the annual average abandonment rate is obtained as follows:

[0066] (8)

[0067] in, It is the power abandonment-capacity expansion function; and is the power abandonment function coefficient; and They are the expansion capacity and maximum expansion capacity of the hydropower station respectively.

[0068] Furthermore, when the expanded capacity of the hydropower station is 0, the corresponding annual average power abandonment rate is obtained through the statistics of historical wind and solar power generation and grid-connected power data; when the wind and solar power are completely consumed and the power abandonment rate is 0, the expanded capacity of the hydropower station is calculated by the following formula:

[0069] (9)

[0070] in, and are the maximum and initial hydropower installed capacity, respectively; The average annual contribution to the landscape.

[0071] 4) Based on the functional relationship between the average annual hydropower generation and the hydropower expansion capacity and the functional relationship between the average annual power abandonment rate and the hydropower expansion capacity, combined with the constructed hydropower expansion objective function, the cost-benefit function of the hydropower station expansion is obtained; wherein, the calculation method of the cost-benefit function of the hydropower station expansion is as follows:

[0072] Substituting formula (5) and (8) into formula (1), we can get the cost-benefit function of hydropower expansion, which is as follows:

[0073] (10)

[0074] in, is the net present value; is the multi-year discount factor of the water-wind-solar complementary system; For the on-grid electricity price; To maintain operating costs; Expand the capacity of hydropower stations; , and is the function coefficient; is the power abandonment function coefficient; is the average annual power generation of wind and solar power; It is the initial investment cost for the expansion of the hydropower station.

[0075] The process of deriving the cost-benefit function of hydropower station expansion to obtain the optimal hydropower station expansion capacity is as follows:

[0076] (11)

[0077] (12)

[0078] in, To expand the capacity of hydropower for the best results; is the net present value; Expand the capacity of hydropower stations; is the multi-year discount factor of the water-wind-solar complementary system; , and is the function coefficient; is the power abandonment function coefficient; For the on-grid electricity price; To maintain operating costs; is the average annual power generation of wind and solar power; is the initial investment cost.

[0079] After the expansion capacity of the target hydropower station is determined, it is applied to the example to determine the expansion capacity of the target hydropower station and compare it with the results of the traditional method; the determination coefficient is used to compare the results of the analytical method with the traditional numerical method. Make an evaluation:

[0080] (13)

[0081] in, is the result of the analytical method; is the result of numerical method; is the average value of the numerical results.

[0082] Taking the Yalong River Ertan Reservoir as an example, the results of the analytical method are compared with those of the traditional numerical method. Figure 2 As shown in the figure, the function obtained by the analytical method can better estimate the annual average hydropower and power abandonment rate under different hydropower expansion capacities, and the determination coefficient with the numerical results is more than 0.9. Figure 3 It can be seen that the optimal expansion capacity of the hydropower station by the analytical method and the numerical method are 1210 and 1250MW respectively. The results show that the proposed method is reasonable for estimating the optimal expansion capacity of the hydropower station in the water-wind-solar hybrid system.

[0083] Table 1 Power generation indicators and changes before and after the expansion of hydropower stations

[0084]

[0085] As can be seen from Table 1, compared with the initial installed capacity, the annual hydropower generation and the amount of electricity fed into the grid increased by about 13% after the expansion. The annual reduction in electricity was reduced from 9.2 billion kWh to 7.3 billion kWh. The above results show that the expansion of hydropower station installed capacity based on existing water resources effectively improves the power generation efficiency and wind and solar power absorption capacity of the water-wind-solar complementary system.

[0086] Based on the available water resources and planned installed capacity of wind and solar power, the research method proposes an analytical method for the optimal hydropower station expansion capacity planning from an economic perspective, constructs a cost-benefit model for hydropower station expansion over the entire life cycle, and reasonably evaluates the power generation, abandoned power, and online power of the multi-energy complementary system under different expansion capacities of the hydropower station, providing a new way to efficiently utilize water resources and rationally plan the installed capacity of the water, wind, and solar multi-energy complementary system.

[0087] The implementation basis of each embodiment of the present invention is achieved by programmed processing through a device with a processor function. Therefore, in engineering practice, the technical solutions and functions of each embodiment of the present invention are encapsulated into various modules. Based on this reality, on the basis of the above-mentioned embodiments, an embodiment of the present invention provides an analytical system for optimizing the capacity expansion of a hydropower station in a water-wind-solar multi-energy complementary system, which is used to execute an analytical method for optimizing the capacity expansion of a hydropower station in a water-wind-solar multi-energy complementary system in the above-mentioned method embodiment.

[0088] Reference Figure 4 The system includes: a first main module, which is used to construct a hydropower expansion target function through a net present value formula; a second main module, which is used to construct a hydropower expansion function based on the relationship between the average annual hydropower generation and the hydropower expansion capacity; a third main module, which is used to analyze the functional relationship between the average annual power abandonment rate and the hydropower expansion capacity to obtain the power abandonment expansion function; a fourth main module, which is used to obtain a hydropower station expansion cost-benefit function based on the functional relationship between the average annual hydropower generation and the hydropower expansion capacity and the functional relationship between the average annual power abandonment rate and the hydropower expansion capacity, combined with the constructed hydropower expansion target function; and a fifth main module, which is used to obtain the optimal hydropower station expansion capacity based on the obtained hydropower station expansion cost-benefit function.

[0089] An embodiment of the present invention provides an analytical system for optimizing the expansion capacity of a hydropower station in a water-wind-solar multi-energy complementary system. By utilizing the above-mentioned modules, the analytical method using historical reservoir scheduling data can avoid complex simulation calculations, and quantify the relationship between the installed capacity of the hydropower station and cost-effectiveness, hydropower generation and power abandonment.

[0090] In summary, the present invention constructs a hydropower expansion objective function based on the net present value formula; proposes a method for calculating the average annual hydropower generation and power abandonment rate, obtains a function related to the expansion capacity, substitutes it into the hydropower expansion objective function, and obtains the cost-benefit function of the hydropower station's full life cycle expansion; finally, the hydropower station's full life cycle expansion cost-benefit function is derived to obtain the expansion capacity of the target hydropower station. The present invention uses the analytical method of the reservoir's historical dispatching data to avoid complex simulation calculations, and quantifies the relationship between the installed capacity of the hydropower station and cost-effectiveness, hydropower generation and power abandonment. And it is applied to examples to determine the expansion capacity of the target hydropower station and compare and verify it with the results of traditional methods to verify the accuracy of the results.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. An analytical method for optimizing the capacity expansion of a hydropower station in a water-wind-solar multi-energy complementary system, characterized in that: The following steps are involved: The objective function of hydropower expansion is constructed through the net present value formula; Based on the relationship between the average annual hydropower generation and the hydropower expansion capacity, a hydropower expansion function is constructed; Analyze the functional relationship between the annual average power abandonment rate and the hydropower expansion capacity, and obtain the power abandonment expansion function; Based on the functional relationship between the average annual hydropower generation and the hydropower expansion capacity, as well as the functional relationship between the average annual power abandonment rate and the hydropower expansion capacity, combined with the constructed hydropower expansion objective function, the cost-benefit function of hydropower station expansion is obtained; Based on the obtained cost-benefit function of hydropower station expansion, the optimal hydropower station expansion capacity is obtained.

2. According to claim 1, the analytical method for optimizing the capacity expansion of a hydropower station in a water-wind-solar multi-energy complementary system is characterized by: The constructed hydropower expansion objective function takes the maximum net present value within the entire life cycle of the hydropower station as the objective function. The functional relationship expression of the maximum net present value is as follows: ； ； in, is the net present value; Expand the capacity of hydropower stations; is the total number of hours in the calculation period; and They are the average annual power generation and initial average annual power generation of the water-wind-solar hybrid system respectively; and They are the annual average wind-solar curtailment rate and the initial annual average wind-solar curtailment rate of the hydro-wind-solar hybrid system; is the average annual power generation of wind and solar power; For the on-grid electricity price; To maintain operating costs; is the initial investment cost; is the social discount rate; is the multi-year discount factor of the water-wind-solar complementary system; It is the maximum expansion capacity of the hydropower station; The number of hours in the calculation period.

3. According to claim 2, the analytical method for optimizing the expansion capacity of a hydropower station in a water-wind-solar multi-energy complementary system is characterized in that: Under different hydropower station expansion capacities, the relationship between system power generation and hydropower-expansion function and between power abandonment rate and power abandonment-expansion function are as follows: ； ； in, It is the hydropower-expansion function; It is the power abandonment-capacity expansion function; and They are the average annual power generation and initial average annual power generation of the water-wind-solar hybrid system respectively; is the average annual power generation of wind and solar power; and They are the annual average wind-solar curtailment rate and the initial annual average wind-solar curtailment rate of the hydro-wind-solar hybrid system; is the function value when the hydropower expansion capacity is 0; is the function value when the hydropower expansion capacity is 0.

4. According to claim 3, the analytical method for optimizing the capacity expansion of a hydropower station in a water-wind-solar multi-energy complementary system is characterized in that: Based on the hydropower expansion function, the functional relationship between the average annual hydropower generation and the hydropower expansion capacity is as follows: ； in, It is the hydropower-expansion function; Expand the capacity of hydropower stations; , , and is the function coefficient; It is the maximum expansion capacity of the hydropower station; It is the maximum annual hydroelectric power generation.

5. According to claim 3, the analytical method for optimizing the expansion capacity of a hydropower station in a water-wind-solar multi-energy complementary system is characterized in that: Based on the power abandonment and expansion function, the functional relationship between the annual average power abandonment rate and the hydropower expansion capacity is obtained as follows: ； in, It is the power abandonment-capacity expansion function; and is the power abandonment function coefficient; and They are the expansion capacity and maximum expansion capacity of the hydropower station respectively.

6. According to claim 1, the analytical method for optimizing the capacity expansion of a hydropower station in a water-wind-solar multi-energy complementary system is characterized in that: Based on the functional relationship between the average annual hydropower generation and the hydropower expansion capacity and the functional relationship between the average annual power abandonment rate and the hydropower expansion capacity, combined with the constructed hydropower expansion objective function, the cost-benefit function of the hydropower station expansion is obtained, and the relationship is as follows: ； in, is the net present value; is the multi-year discount factor of the water-wind-solar complementary system; For the on-grid electricity price; To maintain operating costs; Expand the capacity of hydropower stations; , and is the function coefficient; is the power abandonment function coefficient; is the average annual power generation of wind and solar power; It is the initial investment cost for the expansion of the hydropower station.

7. The analytical method for optimizing the expansion capacity of a hydropower station in a water-wind-solar multi-energy complementary system according to claim 6 is characterized in that: Based on the obtained cost-benefit function of hydropower station expansion, the optimal hydropower station expansion capacity is obtained as follows: ； in, To expand the capacity of hydropower for the best results; is the net present value; Expand the capacity of hydropower stations; is the multi-year discount factor of the water-wind-solar complementary system; , and is the function coefficient; is the power abandonment function coefficient; For the on-grid electricity price; To maintain operating costs; is the average annual power generation of wind and solar power; is the initial investment cost.

8. An analytical system for optimizing the capacity expansion of a hydropower station in a water-wind-solar multi-energy complementary system, characterized in that: include: The first main module: used to construct the hydropower expansion objective function through the net present value formula; The second main module is used to construct a hydropower expansion function based on the relationship between the average annual hydropower generation and the hydropower expansion capacity; The third main module is used to analyze the functional relationship between the annual average power abandonment rate and the hydropower expansion capacity, and obtain the power abandonment expansion function; The fourth main module is used to obtain the cost-benefit function of hydropower station expansion based on the functional relationship between the average annual hydropower generation and the hydropower expansion capacity and the functional relationship between the average annual power abandonment rate and the hydropower expansion capacity, combined with the constructed hydropower expansion objective function; The fifth main module is used to obtain the optimal hydropower station expansion capacity based on the obtained hydropower station expansion cost-benefit function.

Images