Capacity configuration method for electricity-pumped storage-wind-light combined power generation system

Abstract

The invention discloses a capacity configuration method for a hydroelectric-pumped storage-wind-light combined power generation system. The method comprises the following steps: step (1), generating a typical wind power and photovoltaic output scene; step (2), selecting runoff corresponding to typical frequency according to runoff frequency distribution characteristics to generate runoff scenes of all seasons; step (3), establishing a two-stage complementary strategy of water and electricity coordinated pumped storage complementary wind and light operation; step (4), constructing a capacity optimization configuration mathematical model of the hydropower-pumped storage-wind-light multi-energy complementary system; step (5), constructing an all-scene optimal cooperative operation model of the wind power plant and the photovoltaic power station under different planned installed capacity conditions; (6), a wind-light capacity and matched channel capacity configuration scheme is formulated for the all-scene optimal cooperative operation result obtained in the step (5) by adopting a wind-light capacity and matched channel capacity configuration method of the scene set optimization result; according to the invention, water and electricity combined pumped storage self-adaptive complementary wind and light output is realized, and the stability of the total output of the intercommunication channel is effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of wind power and photovoltaic installed capacity and supporting transmission channel capacity configuration in a hydropower-pumped storage-wind-solar combined power generation system, and in particular to a capacity configuration method for a hydropower-pumped storage-wind-solar combined power generation system. Background Art

[0002] The deep adjustment of energy structure and emission reduction strategy have rapidly promoted the development and utilization of clean energy represented by photovoltaic and wind power. Doing a good job in the development and utilization of clean energy has been and will continue to be the top priority of my country's future energy work. my country's photovoltaic, wind power, hydropower clean energy and their development and utilization are generally distributed in the west and less in the east, with the Hu Huanyong Line as the boundary, forming an energy encirclement of the "Three Norths" and the coast. From the perspective of energy supply and demand and clean electricity substitution, the demand in the socially and economically developed areas east of the Hu Huanyong Line is significantly greater than that in the areas with excellent resource endowments on the west side. The spatial mismatch between clean energy supply and demand will inevitably require my country to take an energy development path that suits itself.

[0003] Wind and solar energy have special regional endowments and inherent intermittent, volatile and random characteristics. Large-scale and high-proportion direct grid connection and consumption have an impact on the stability and safety of grid operation, and increase the demand for grid regulation capacity; especially when adopting UHV DC cross-regional transmission and consumption, the stable transmission process requires high requirements. If the grid-connected power process does not meet the requirements, it will lead to frequent adjustment or even failure of transmission equipment. Based on this, considering the endowment of wind and solar resources and their inherent intermittent, volatile and random characteristics, combined with the flexible characteristics of hydropower output regulation, large-scale water-wind-solar clean energy systems in the west have been developed and planned one after another, and the clean electricity produced will also be transmitted to the eastern region through UHV transmission lines. With the access and scale of wind and solar energy in the basin, new complementary operation requirements have increased the difficulty of hydropower station dispatching decisions. How to adapt to the integration of multiple types of new energy on the basis of ensuring the original functional requirements, realize the multi-time scale and multi-type complementarity of energy and the compensation of clean energy for water resources has become a difficult problem that basin development and management agencies need to solve urgently.

[0004] In recent years, China has proposed a hydropower-pumped-storage-wind-solar multi-energy complementary system development model that uses the upper and lower reservoirs of cascade hydropower stations as regulating pools to develop pumped-storage power stations. Adding pumped-storage power stations will effectively improve the ability of hydropower stations to complement wind and solar power, making the multi-energy complementary system more secure for grid-connected power generation; but the above-mentioned projects and equipment as well as supporting transmission channels have significantly increased the investment, and how to balance input and output is the key problem that needs to be solved first. On the other hand, hydropower stations have their own planning functions, inflow characteristics, regulation and regulation performance. After participating in multi-energy complementary operation, how to keep their functions unchanged, while making the best use of pumping and storage to achieve the best operation and regulation of the complementary system is also a key problem that needs to be solved. Therefore, it is necessary to propose a capacity configuration method for a hydropower-pumped-storage-wind-solar combined power generation system based on bundled transmission of ultra-high voltage direct current channels. Summary of the invention

[0005] In view of the difficulties in the prior art, the present invention proposes a capacity configuration method for a hydropower-pumped storage-wind-solar combined power generation system based on bundled transmission of ultra-high voltage direct current channels. The method of the present invention can be realized under the condition that the installed capacity of hydropower and the installed capacity of pumped storage power stations are determined, taking into account the uncertainty of wind power and photovoltaic energy and runoff in the large-scale hydropower-pumped storage-wind-solar multi-energy complementary system and the characteristics of ultra-high voltage cross-grid power transmission, and using the proposed hydropower and pumped storage two-stage complementary strategy to construct a capacity optimization configuration mathematical model for the hydropower-pumped storage-wind-solar multi-energy complementary system; multi-objective and multi-level comprehensive evaluation indicators of the hydropower-pumped storage-wind-solar multi-energy complementary system are proposed for the full scenario simulation optimization results, and a system full life cycle evaluation method considering multi-object costs is established; based on the comprehensive system evaluation, the optimal capacity configuration scheme of the hydropower-pumped storage-wind-solar multi-energy complementary system under ultra-high voltage direct current transmission and consumption and its corresponding system operation mode are formed, in which the hydropower combined pumped storage adaptively complements the wind and solar output, and effectively improves the stability of the total output sent by the mutual channel. The present invention can provide technical support for the planning and construction of a hydropower-pumped storage-wind-solar multi-energy complementary system, and is suitable for promotion and application in the configuration of wind power, photovoltaics and supporting channel capacity in a large-scale hydropower-pumped storage-wind-solar multi-energy complementary system.

[0006] In order to solve the problems of the prior art, the present invention adopts the following technical solutions:

[0007] A method for configuring the capacity of a hydropower-pumped storage-wind-solar combined power generation system comprises the following steps:

[0008] Step (1), the historical measured daily output process of the wind farms and photovoltaic power stations built in the study area is divided into four categories according to seasons, and typical wind power and photovoltaic output scenarios are generated respectively;

[0009] Step (2), dividing the historical average daily runoff data of the hydrological station upstream of the hydropower station into four categories according to season, calculating the frequency of the historical average daily runoff respectively, and selecting the runoff corresponding to the typical frequency according to the runoff frequency distribution characteristics to generate the runoff scenario of each season;

[0010] Step (3), according to the characteristics of cross-grid power transmission of ultra-high voltage transmission lines of large-scale hydropower-pumped storage-wind-solar combined power generation system, and taking into account the uncertainty of wind power and photovoltaic output and reservoir runoff, and the output characteristics of hydropower and pumped storage units, the total output process of the hydropower-pumped storage-wind-solar combined power generation system under the ultra-high voltage transmission demand is described by using time parameters and characteristic parameters, and a two-stage complementary strategy of hydropower coordinated pumped storage and complementary wind and solar operation is set;

[0011] Step (4), constructing a capacity optimization configuration mathematical model of a hydropower-pumped storage-wind-solar multi-energy complementary system based on the complementary strategy of step (3);

[0012] Step (5), using the typical wind power-photovoltaic combined scenario daily power generation process obtained in step (1) and the typical runoff scenario obtained in step (2) as input variables of the multi-objective optimization model established in step (4), using the multi-objective optimization algorithm to solve the model, and obtaining the channel delivery capacity and the optimal coordinated operation process under different planned installed capacity conditions, and calculating the daily power generation (power) process and channel delivery process of the hydropower station and pumped storage power station;

[0013] Step (6), taking into account the complementary capacity of hydropower combined with pumped storage, channel transmission characteristics, wind power and photovoltaic grid-connected electricity prices, component costs, land costs, social discount rates and other factors, a method for configuring wind and solar capacity and supporting channel capacity based on the optimization results of the scenario set is proposed;

[0014] Step (7), based on the optimal coordinated operation results of the entire scenario obtained in step (5), the configuration method proposed in step (6) is adopted to formulate a configuration plan for wind and solar capacity and supporting channel capacity according to the goal orientation of managers and decision makers.

[0015] Furthermore, in step (1), spring is March, April, and May, summer is June, July, and August, autumn is September, October, and November, and winter is December, January, and February; the scenario generation step specifically includes: using Copu la function to construct a wind power-photovoltaic power joint probability distribution model for each season and each period; using Latin hypercube sampling method to sample the output data of each season and each period, and obtain the wind-solar joint output data set of each season; based on the samples with random characteristics obtained by sampling, a large number of wind-solar joint output initial scenario sets that meet the fluctuation characteristics of wind power and photovoltaic output are generated; finally, using the FCM clustering method of eigenvalue dimensionality reduction to reduce the initial scenario set, and obtain a typical wind-solar joint output scenario.

[0016] Furthermore, in step (2), spring is March, April, and May, summer is June, July, and August, autumn is September, October, and November, and winter is December, January, and February; the steps for generating runoff scenarios for each season specifically include: for the area enclosed by the inflow runoff frequency curve and the coordinate axis, different probability intervals are used for division, and the area enclosed by each boundary of each interval represents the inflow flow value in the runoff scenario, and finally a typical runoff scenario is obtained.

[0017] Furthermore, in step (3), the two-stage complementary strategy includes: in the first complementary regulation stage, pumped storage performs complementary regulation on the wind-solar combined output, and complements the wind-solar output curve into a multi-segment line. In each segment of the multi-segment line, when the output of the segment is greater than the wind-solar output, the pumped storage performs power generation, and when the output of the segment is less than the wind-solar output, the pumped storage performs water pumping; in the second complementary regulation stage, hydropower performs complementary regulation on the multi-segment line output obtained in the first stage, and hydropower compensates it into a U+1 segment line; wherein: the U+1 segment line divides the total output process of the hydropower-pumped storage-wind-solar combined power generation system into U+1 stages according to the ultra-high voltage transmission characteristics, and each stage is subdivided into a number of time periods according to the decision time step. The total output of the hydropower-pumped storage-wind-solar combined power generation system in all time periods in each stage is a constant value, and characteristic parameters are used to characterize the output characteristics of different stages;

[0018] Furthermore, in step (4), the hydropower-pumped storage-wind-solar multi-energy complementary system capacity optimization configuration mathematical model is a multi-objective optimization model, which is composed of an objective function, decision variables and constraints:

[0019] a. Objective function:

[0020] f1: Maximize the power generation of the complementary system

[0021]

[0022] Where:

[0023] is the total output of the complementary system in the jth period, (MW);

[0024] is the output of the hydropower station in the jth period, (MW);

[0025] is the combined output of wind power and photovoltaic power in the jth period, (MW);

[0026] is the pumping power of the pumped storage power station in the jth period, (MW);

[0027] is the power generation capacity of the pumped storage power station in the jth period, (MW);

[0028] Represents the comprehensive output coefficient of the hydropower station in the jth period, which is related to the unit output and the generating head;

[0029] represents the average power generation flow of the hydropower station in the jth period, (m 3 / s);

[0030] represents the average power generation head of the hydropower station in the jth period, (m);

[0031] C wp is the total capacity of wind power and photovoltaic power, (MW);

[0032] is the proportion of PV capacity in the total wind-solar capacity, (MW);

[0033] is the installed capacity of wind power in megawatts in the jth period, (MW);

[0034] is the installed capacity of PV in megawatts in the jth period, (MW);

[0035] J is the number of time periods in the scheduling period;

[0036] is the operating status of the pumped storage unit in the jth period, (MW);

[0037] represents the average power generation flow of the pumped storage power station in the jth period, (m 3 / s);

[0038] represents the average pumping flow of the pumped storage power station in the jth period, (m 3 / s);

[0039] H ph Represents the water level difference between the upper and lower reservoirs of the pumped storage power station, (m);

[0040] η p are the comprehensive output coefficients of the pumped storage power station under pumping conditions;

[0041] η t are the comprehensive output coefficients of the pumped storage power station under power generation conditions;

[0042] f2: Minimize the total system output fluctuation

[0043]

[0044] Where:

[0045] C line is the total capacity of the power transmission channel, (MW);

[0046] b. Decision variables

[0047] The total channel capacity C line , time parameter t of the polyline u and the output parameter P of the polyline u+1 is the decision variable.

[0048] c. Constraints, as follows:

[0049] ① System power balance constraints:

[0050]

[0051] ②Sending channel capacity constraints:

[0052] C hydro <C line ≤C line，max

[0053] In the formula, C hydro is the total installed capacity of the hydropower station, (MW);

[0054] ③ Constraints on total wind and solar capacity:

[0055] 0<C wp ≤C wp,max

[0056] In the formula, C wp，max is the upper limit of total wind and solar capacity, (MW);

[0057] ④ Constraints on the total capacity of pumped storage power stations:

[0058] 0<C ph ≤C ph,max

[0059] In the formula, C ph，max is the upper limit of total wind and solar capacity, (MW);

[0060] ⑤Power constraints of pumped storage power stations:

[0061]

[0062] In the formula, are the minimum and maximum outputs of the pumped storage power station in the jth period, respectively (MW).

[0063] ⑥ Pumped storage power station operating conditions constraints:

[0064]

[0065] ⑦Reservoir water balance constraints:

[0066]

[0067] Where V j represents the initial storage capacity of the reservoir in the jth period of the day, m 3 ; represents the average inflow of the hydropower station in the jth period of the day, (m 3 / s); represents the water discharge of the hydropower station in the jth period of the day, (m 3 / s); Δt is the duration of a time period, (h);

[0068] ⑧Hydropower station output constraints:

[0069]

[0070] In the formula, represents the minimum output of the hydropower station in the jth period of the day, (MW); represents the maximum output of the hydropower station in the jth period of the day, (MW);

[0071] ⑨Hydropower station output climbing constraints:

[0072]

[0073] In the formula, UP hydro Represents the maximum value of the hydropower station's output when it climbs upward (load increase), (MW); LP hydro Represents the maximum output of the hydropower station when it is ramping down (load reduction), (MW).

[0074] ⑩ Constraints on the discharge flow allowed by hydropower stations:

[0075]

[0076] In the formula, represents the minimum discharge flow allowed in the jth period of the hydropower station day, (m 3 / s); represents the maximum discharge flow allowed in the jth period of the hydropower station day, (m 3 / s);

[0077] Hydropower station power generation head constraints:

[0078]

[0079] In the formula, represents the minimum generating head of the hydropower station in the jth period of the day, (m); represents the maximum generating head of the hydropower station in the jth period of the day, (m);

[0080] Reservoir water level constraints:

[0081]

[0082] In the formula, represents the lower limit water level of the reservoir in the jth period of the day, (m); Represents the lower limit water level of the reservoir during the jth period of the day, (m).

[0083] The initial and final water level constraints of the reservoir operation period:

[0084] Z1=Z start Z J =Z end

[0085] In the formula, Z start represents the initial reservoir water level during the reservoir operation period, (m); Z end Represents the reservoir water level at the end of the reservoir operation period, (m).

[0086] Total output constraint:

[0087]

[0088] In the formula, C trans，min , C trans，max They are the minimum and maximum outputs allowed by the output channel, respectively (MW).

[0089] Furthermore, in step (5), the total wind and solar capacity value as the input variable is set to start from the minimum wind and solar capacity, and to increase in equal value until the upper limit of the wind and solar capacity that satisfies both the maximum power generation of the complementary system and the minimum fluctuation of the total output of the system is calculated;

[0090] The optimization algorithm adopts one of dynamic programming and its improved algorithm or heuristic algorithm:

[0091] The dynamic programming and its improved algorithm include discrete differential dynamic programming, successive asymptotic dynamic programming and successive optimization method.

[0092] The heuristic algorithms include genetic algorithm, artificial neural network algorithm, particle swarm algorithm and ant colony algorithm.

[0093] Furthermore, in step (6), the capacity configuration method is specifically as follows: an annual time scale indicator system is proposed to characterize the comprehensive characteristics of the hydropower-pumped storage-wind-solar multi-energy complementary system; a system full life cycle (25 years) evaluation method that considers multi-object costs is established; and a wind and solar capacity and supporting channel capacity configuration plan is formulated based on the full life cycle evaluation results.

[0094] Beneficial Effects

[0095] Compared with the traditional technical solution, the beneficial effects brought by the present invention are:

[0096] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: The present invention proposes a capacity configuration method for a hydropower-pumped-storage-wind-solar combined power generation system based on bundled transmission of ultra-high voltage direct current channels. A typical combined wind power-photovoltaic output scenario daily output process is generated based on the historical measured daily output process of the built wind farms and photovoltaic power stations in the study area. A runoff scenario is generated based on the historical average daily runoff data of the hydrological station upstream of the hydropower station. According to the characteristics of cross-network power transmission of ultra-high voltage transmission lines of large-scale hydropower-pumped-storage-wind-solar combined power generation system and the regulation capacity of hydropower stations and pumped storage power stations, a two-stage complementary strategy for the hydropower-pumped-storage-wind-solar combined power generation system is set. A mathematical model for capacity configuration of the hydropower-pumped-storage-wind-solar combined power generation system is constructed, and an optimization algorithm is used to solve it, and the optimal coordinated operation process of the wind farm and photovoltaic power station under different planned installed capacity conditions is obtained. A method for configuring wind and solar capacity and supporting channel capacity based on the optimization results of the scenario set is proposed, and the optimal capacity configuration scheme of the hydropower-pumped-storage-wind-solar combined power generation system is determined according to the goal orientation of managers and decision makers.

[0097] The capacity configuration method proposed in the present invention takes into account the characteristics of ultra-high voltage transmission and the uncertainty of the output of wind, solar and water energy, and determines the capacity configuration scheme of the hydropower-pumped storage-wind-solar combined power generation system based on a comprehensive evaluation of the entire life cycle. It can provide technical support for the planning and construction of the hydropower-pumped storage-wind-solar combined power generation system, and is suitable for promotion and application in the configuration of wind power, photovoltaic capacity and supporting transmission channel capacity in large-scale hydropower-pumped storage-wind-solar combined power generation systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] Figure 1 It is a flowchart for executing the technical solution of the present invention;

[0099] Figure 2 The daily power generation process of a typical wind and solar scenario under unit megawatt installed capacity in step (1) of the method of the present invention;

[0100] Figure 3 is the empirical frequency curve of runoff entering the reservoir in different seasons in step (2) of the method of the present invention;

[0101] Figure 4 Schematic diagram of the two-stage complementary strategy of the hydropower-pumped storage-wind-solar combined power generation system in step (3) of the method of the present invention;

[0102] Figure 5 The system coordinated operation optimization result under all runoff scenarios in a certain wind-solar scenario in step (5) of the method of the present invention;

[0103] Figure 6 The calculation results of the technical and economic characteristics of the system in step (6) of the method of the present invention. DETAILED DESCRIPTION

[0104] The following is combined with Figure 1 to Figure 6 The present invention is described as follows:

[0105] To further illustrate the technical solutions and features of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments, but the content of the present invention is not limited to the content described in the specific embodiments.

[0106] This example takes a hydropower station and its supporting pumped storage power station as an example. Figure 1 As shown, a capacity configuration method for a hydropower-pumped storage-wind-solar combined power generation system based on bundled transmission of UHV DC channels is implemented in the following specific steps:

[0107] Step 101: Divide the historical measured daily output process (time step of 10 minutes) of the existing wind farms and photovoltaic power stations in the study area by season (spring is March, April, and May, summer is June, July, and August, autumn is September, October, and November, and winter is December, January, and February), and use the Copula function to construct a joint probability distribution model of wind power and photovoltaic output in each season and time period; use the Latin hypercube sampling method to sample the output data of each season and time period, and obtain the wind-solar joint output data set of each season; based on the random feature samples obtained by sampling, generate a large number of wind-solar joint output initial scenario sets that meet the fluctuation characteristics of wind power and photovoltaic output, and use the output fluctuation interval constraints of each time period to eliminate the scenarios that do not meet the requirements; finally, use the FCM clustering method of eigenvalue dimensionality reduction to reduce the initial scenario set to obtain the typical wind-solar scenarios of each season (see Figure 2 ). The multiple ratio method is used to obtain the daily output process of typical combined wind power-photovoltaic output scenarios in each season under different planned installed capacity conditions of wind farms and photovoltaic power stations.

[0108] Step 102: Calculate the frequency of historical daily average runoff data of the upstream hydrological station of the hydropower station by season (see Figure 3), the area enclosed by the inflow runoff frequency curve and the coordinate axis is divided into different probability intervals. The area enclosed by each boundary of each interval represents the inflow flow value in the runoff scenario, and finally a typical runoff scenario is obtained (see Table 1).

[0109] Table 1 Inflow values ​​and corresponding probabilities of each runoff scenario

[0110]

[0111]

[0112] Step 103: According to the UHV transmission characteristics, the total output process of the hydropower-pumped storage-wind-solar combined power generation system is divided into U+1 stages using time parameters. Each stage is subdivided into several time periods according to the decision time step. The output of the hydropower-pumped storage-wind-solar combined power generation system in all time periods in each stage is a constant value. The characteristic parameters are used to characterize the output characteristics of different stages (see Figure 4 );

[0113] Step 104: construct a capacity configuration mathematical model for the hydropower-pumped storage-wind-solar combined power generation system.

[0114] The multi-objective optimization model is composed of objective function, decision variables and constraints:

[0115] a. Objective function:

[0116] f1: Maximize the power generation of the complementary system

[0117]

[0118] Where:

[0119] is the total output of the complementary system in the jth period, (MW);

[0120] is the output of the hydropower station in the jth period, (MW);

[0121] is the combined output of wind power and photovoltaic power in the jth period, (MW);

[0122] is the pumping power of the pumped storage power station in the jth period, (MW);

[0123] is the power generation capacity of the pumped storage power station in the jth period, (MW);

[0124] Represents the comprehensive output coefficient of the hydropower station in the jth period, which is related to the unit output and the generating head;

[0125] represents the average power generation flow of the hydropower station in the jth period, (m 3 / s);

[0126] represents the average power generation head of the hydropower station in the jth period, (m);

[0127] C wp is the total capacity of wind power and photovoltaic power, (MW);

[0128] γ is the proportion of PV capacity in the total wind-solar capacity, (MW);

[0129] is the installed capacity of wind power in megawatts in the jth period, (MW);

[0130] is the installed capacity of PV in megawatts in the jth period, (MW);

[0131] J is the number of time periods in the scheduling period;

[0132] is the operating status of the pumped storage unit in the jth period, (MW);

[0133] represents the average power generation flow of the pumped storage power station in the jth period, (m 3 / s);

[0134] represents the average pumping flow of the pumped storage power station in the jth period, (m 3 / s);

[0135] H ph Represents the water level difference between the upper and lower reservoirs of the pumped storage power station, (m);

[0136] η p are the comprehensive output coefficients of the pumped storage power station under pumping conditions;

[0137] η t are the comprehensive output coefficients of the pumped storage power station under power generation conditions;

[0138] f2: Minimize the total system output fluctuation

[0139]

[0140] Where:

[0141] C lineis the total capacity of the power transmission channel (MW).

[0142] b. Decision variables

[0143] The total channel capacity C line , time parameter t of the polyline u and the output parameter P of the polyline u+1 is the decision variable.

[0144] c. Constraints, as follows:

[0145] ① System power balance constraints:

[0146]

[0147] ②Sending channel capacity constraints:

[0148] C hydro <C line ≤C line，max

[0149] In the formula, C hydro is the total installed capacity of the hydropower station, (MW).

[0150] ③ Constraints on total wind and solar capacity:

[0151] 0<C wp ≤C wp,max

[0152] In the formula, C wp，max is the upper limit of total wind and solar capacity (MW).

[0153] ④ Constraints on the total capacity of pumped storage power stations:

[0154] 0<C ph ≤C ph，max

[0155] In the formula, C ph，max is the upper limit of total wind and solar capacity (MW).

[0156] ⑤Power constraints of pumped storage power stations:

[0157]

[0158] In the formula, are the minimum and maximum outputs of the pumped storage power station in the jth period, respectively (MW).

[0159] ⑥ Pumped storage power station operating conditions constraints:

[0160]

[0161] ⑦Reservoir water balance constraints:

[0162]

[0163] Where V j represents the initial storage capacity of the reservoir in the jth period of the day, m 3 ; represents the average inflow of the hydropower station in the jth period of the day, (m 3 / s); represents the water discharge of the hydropower station in the jth period of the day, (m 3 / s); Δt is the duration of a time period, (h).

[0164] ⑧Hydropower station output constraints:

[0165]

[0166] In the formula, represents the minimum output of the hydropower station in the jth period of the day, (MW); represents the maximum output of the hydropower station in the jth period of the day, (MW);

[0167] ⑨Hydropower station output climbing constraints:

[0168]

[0169] In the formula, UP hydro Represents the maximum value of the hydropower station's output when it climbs upward (load increase), (MW); LP hydro Represents the maximum output of the hydropower station when it is ramping down (load reduction), (MW).

[0170] ⑩ Constraints on the discharge flow allowed by hydropower stations:

[0171]

[0172] In the formula, represents the minimum discharge flow allowed in the jth period of the hydropower station day, (m 3 / s); represents the maximum discharge flow allowed in the jth period of the hydropower station day, (m 3 / s).

[0173] Hydropower station power generation head constraints:

[0174]

[0175] In the formula, represents the minimum generating head of the hydropower station in the jth period of the day, (m); Represents the maximum generating head of the hydropower station in the jth period of the day, (m).

[0176] Reservoir water level constraints:

[0177]

[0178] In the formula, represents the lower limit water level of the reservoir in the jth period of the day, (m); Represents the lower limit water level of the reservoir during the jth period of the day, (m).

[0179] The initial and final water level constraints of the reservoir operation period:

[0180] Z1=Z start Z J =Z end

[0181] In the formula, Z start represents the initial reservoir water level during the reservoir operation period, (m); Z end Represents the reservoir water level at the end of the reservoir operation period, (m).

[0182] Total output constraint:

[0183]

[0184] In the formula, C trans，min , C trans，max They are the minimum and maximum outputs allowed by the output channel, respectively (MW).

[0185] Step 105: Combine the typical wind-PV scenario obtained in step (1) and the runoff scenario obtained in step (2), and use the typical wind-PV scenario and the wind-PV capacity ratio as input variables of the multi-objective optimization model established in step (4). Use the optimization algorithm to solve the optimal coordinated operation mode of the hydropower-pumped storage-wind-solar combined power generation system under all scenarios, and calculate the various output processes (see Figure 5 ).

[0186] Step 106: Calculate and count the technical and economic characteristics of the hydropower-pumped storage-wind-solar combined power generation system under all scenarios. Determine the optimal capacity configuration scheme of the hydropower-pumped storage-wind-solar combined power generation system based on the goal orientation of managers and decision makers (see Figure 6 ). For example: If the goal of managers and decision makers is to achieve greater economic benefits for the system, the optimal configuration of the hydropower-pumped storage-wind-solar combined power generation system can be obtained as follows: 3000MW of wind power, 1500MW of photovoltaic power, and 3700MW of supporting channel capacity.

[0187] Although the present invention has been described above, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can make many modifications without departing from the purpose of the present invention, which are all within the protection of the present invention.

Claims

1. A method for configuring the capacity of a hydropower-pumped storage-wind-solar combined power generation system, characterized in that: The steps include: Step (1), the historical measured daily output process of the wind farms and photovoltaic power stations built in the study area is divided into four categories according to seasons, and typical wind power and photovoltaic output scenarios are generated respectively; Step (2), dividing the historical average daily runoff data of the hydrological station upstream of the hydropower station into four categories according to season, calculating the frequency of the historical average daily runoff respectively, and selecting the inflow corresponding to the typical frequency according to the runoff frequency distribution characteristics to generate the runoff scenario of each season; Step (3), according to the characteristics of cross-grid power transmission of ultra-high voltage transmission lines of large-scale hydropower-pumped storage-wind-solar combined power generation system, and taking into account the uncertainty of wind power output, photovoltaic output and reservoir runoff, and the output characteristics of hydropower and pumped storage units, the total output process of the hydropower-pumped storage-wind-solar combined power generation system under the ultra-high voltage transmission demand is described by using time parameters and characteristic parameters, and a two-stage complementary strategy of hydropower coordinated pumped storage and complementary wind and solar operation is set; Step (4), constructing a capacity optimization configuration mathematical model of a hydropower-pumped storage-wind-solar multi-energy complementary system based on the complementary strategy of step (3); Step (5), using the typical wind power-photovoltaic joint scenario daily power generation process obtained in step (1) and the typical runoff scenario obtained in step (2) as input variables of the multi-objective optimization model established in step (4), using the multi-objective optimization algorithm to solve the model, and obtaining the full-scenario optimal coordinated operation model of the wind farm and the photovoltaic power station under different planned installed capacity conditions; calculating the daily power generation of the hydropower station and the pumped storage power station and the channel delivery power according to the full-scenario optimal coordinated operation model; Step (6), adopting the wind and solar capacity and supporting channel capacity configuration method based on the scenario set optimization results to formulate a wind and solar capacity and supporting channel capacity configuration plan based on the full scenario optimal coordinated operation results obtained in step (5).

2. A method for configuring the capacity of a hydropower-pumped storage-wind-solar combined power generation system according to claim 1, characterized in that: In step (1), the process of generating typical wind power and photovoltaic output scenarios includes: The Copula function is used to construct the joint probability distribution model of wind power and photovoltaic power output in each season and time period; The Latin hypercube sampling method is used to sample the output data of each season and each period, and the wind-solar joint output data set of each season is obtained; Based on the samples with random characteristics obtained by sampling, a large number of initial scenarios of wind-solar combined output that meet the fluctuation characteristics of wind power and photovoltaic output are generated; The FCM clustering method with eigenvalue dimensionality reduction was used to reduce the initial scenario set and obtain a typical wind-solar joint output scenario.

3. A method for configuring the capacity of a hydropower-pumped storage-wind-solar combined power generation system according to claim 1, characterized in that: In step (3), the two-stage complementary strategy includes: In the first complementary regulation stage, pumped storage performs complementary regulation on the wind-solar combined output, and wind-solar output curves are complemented into multiple lines. In each segment of the multiple lines, when the output of the segment is greater than the wind-solar output, pumped storage performs power generation, and when the output of the segment is less than the wind-solar output, pumping is performed. In the second complementary regulation stage, hydropower makes complementary regulation on the multi-segment line output obtained in the first stage, and hydropower compensates it into a U+1 segment line; where: The U+1 section line divides the total output process of the hydropower-pumped-storage-wind-solar combined power generation system into U+1 stages according to the ultra-high voltage transmission characteristics and U time parameters. Each stage is subdivided into several time periods according to the decision time step. The total output of the hydropower-pumped-storage-wind-solar combined power generation system in all time periods in each stage is a constant value, and characteristic parameters are used to characterize the output characteristics of different stages.

4. A method for configuring the capacity of a hydropower-pumped storage-wind-solar combined power generation system according to claim 1, characterized in that: In step (4), the hydropower-pumped storage-wind-solar multi-energy complementary system capacity optimization configuration mathematical model is a multi-objective optimization model, which is composed of an objective function, decision variables and constraints: a. Objective function: f1: Maximize the power generation of the complementary system Where: is the total output of the complementary system in the jth period, (MW); is the output of the hydropower station in the jth period, (MW); is the combined output of wind power and photovoltaic power in the jth period, (MW); is the pumping power of the pumped storage power station in the jth period, (MW); is the power generation capacity of the pumped storage power station in the jth period, (MW); Represents the comprehensive output coefficient of the hydropower station in the jth period, which is related to the unit output and the generating head; represents the average power generation flow of the hydropower station in the jth period, (m 3 / s); represents the average power generation head of the hydropower station in the jth period, (m); C wp is the total capacity of wind power and photovoltaic power, (MW); γ is the proportion of PV capacity in the total wind-solar capacity, (MW); is the installed capacity of wind power in megawatts in the jth period, (MW); is the installed capacity of PV in megawatts in the jth period, (MW); J is the number of time periods in the scheduling period; is the operating status of the pumped storage unit in the jth period, (MW); represents the average power generation flow of the pumped storage power station in the jth period, (m 3 / s); represents the average pumping flow of the pumped storage power station in the jth period, (m 3 / s); H ph Represents the water level difference between the upper and lower reservoirs of the pumped storage power station, (m); η p are the comprehensive output coefficients of the pumped storage power station under pumping conditions; η t are the comprehensive output coefficients of the pumped storage power station under power generation conditions; f2: Minimize the total system output fluctuation Where: C line is the total capacity of the power transmission channel, (MW); b. Decision variables The total channel capacity C line , time parameter t of the polyline u and the output parameter P of the polyline u+1 is the decision variable. c. Constraints, as follows: ① System power balance constraints: ②Sending channel capacity constraints: C hydro <C line ≤C line，max In the formula, C hydro is the total installed capacity of the hydropower station, (MW). ③ Constraints on total wind and solar capacity: 0<C wp ≤C wp，max In the formula, C wp，max is the upper limit of total wind and solar capacity (MW). ④ Constraints on the total capacity of pumped storage power stations: 0<C ph ≤C ph,max In the formula, C ph，max is the upper limit of total wind and solar capacity (MW). ⑤Power constraints of pumped storage power stations: In the formula, are the minimum and maximum outputs of the pumped storage power station in the jth period, respectively (MW). ⑥ Pumped storage power station operating conditions constraints: ⑦Reservoir water balance constraints: Where V j represents the initial storage capacity of the reservoir in the jth period of the day, m 3 ; represents the average inflow of the hydropower station in the jth period of the day, (m 3 / s); represents the water discharge of the hydropower station in the jth period of the day, (m 3 / s); Δt is the duration of a time period, (h). ⑧Hydropower station output constraints: In the formula, represents the minimum output of the hydropower station in the jth period of the day, (MW); represents the maximum output of the hydropower station in the jth period of the day, (MW); ⑨Hydropower station output climbing constraints: In the formula, UP hydro Represents the maximum value of the hydropower station's output when it climbs upward (load increase), (MW); LP hydro Represents the maximum output of the hydropower station when it is ramping down (load reduction), (MW); ⑩ Constraints on the discharge flow allowed by hydropower stations: In the formula, represents the minimum discharge flow allowed in the jth period of the hydropower station day, (m 3 / s); represents the maximum discharge flow allowed in the jth period of the hydropower station day, (m 3 / s); Hydropower station power generation head constraints: In the formula, represents the minimum generating head of the hydropower station in the jth period of the day, (m); represents the maximum generating head of the hydropower station in the jth period of the day, (m); Reservoir water level constraints: In the formula, represents the lower limit water level of the reservoir in the jth period of the day, (m); represents the lower limit water level of the reservoir in the jth period of the day, (m); The initial and final water level constraints of the reservoir operation period: Z1=Z start ,WITH J =Z end In the formula, Z start represents the initial reservoir water level during the reservoir operation period, (m); Z end represents the reservoir water level at the end of the reservoir operation period, (m); Total output constraint: In the formula, C trans，min , C trans，max They are the minimum and maximum outputs allowed by the output channel, respectively (MW).

5. A method for configuring the capacity of a hydropower-pumped storage-wind-solar combined power generation system according to claim 1, characterized in that: In step (5), the total wind and solar capacity value as the input variable is set to start from the minimum wind and solar capacity, and to increase in equal value until the upper limit of the wind and solar capacity that satisfies both the maximum power generation of the complementary system and the minimum fluctuation of the total output of the system is calculated; The optimization algorithm adopts one of dynamic programming and its improved algorithm or heuristic algorithm: The dynamic programming and its improved algorithm include discrete differential dynamic programming, successive asymptotic dynamic programming and successive optimization method. The heuristic algorithms include genetic algorithm, artificial neural network algorithm, particle swarm algorithm and ant colony algorithm.

6. A method for configuring the capacity of a hydropower-pumped storage-wind-solar combined power generation system according to claim 1, characterized in that: In step (6), the capacity configuration includes: proposing an annual time scale indicator system to characterize the comprehensive characteristics of the hydropower-pumped storage-wind-solar multi-energy complementary system; establishing a system full life cycle evaluation method that considers multi-object costs; and formulating a wind and solar capacity and supporting channel capacity configuration plan based on the full life cycle evaluation results.

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