Water-wind-light-storage complementary scheduling method considering seasonal regulation characteristics of hybrid pumped storage power station

Abstract

The invention discloses a hybrid pumped storage power station seasonal regulation characteristic-considered water-wind-light-storage complementary scheduling method, which relates to the technical field of energy scheduling, and comprises the following steps: additionally building a pump station between built conventional cascade hydropower stations to build a hybrid pumped storage power station which has pumped storage and runoff power generation functions; the hybrid pumped storage power station and the cascade water-wind-light power station are co-constructed to form a water-wind-light-storage complementary system; constructing a water-wind-light-storage complementary long and short term nested scheduling model considering seasonal regulation characteristics of the hybrid pumped storage power station, and taking maximum power generation benefits as a model objective function; based on a dynamic programming successive approximation algorithm, a pumping power generation working condition conversion model is introduced to construct a model solving method; solving the scheduling model through a model solving method, and obtaining a water-wind-light-storage complementary power generation plan of the seasonal regulation characteristics of the hybrid pumped storage power station; and while the short-term peak shifting benefit and the new energy consumption level are improved, the long-term water storage and energy storage effects of abundant storage and dry supplement of the hybrid pumped storage power station are brought into full play.

Description

Technical Field

[0001] The present invention relates to the technical field of energy dispatching, and specifically to a water-wind-solar-storage complementary dispatching method taking into account the seasonal regulation characteristics of a hybrid pumped-storage power station. Background Art

[0002] In order to achieve the "dual carbon" goals, support the safe and stable operation of the power system and the high-level consumption of new energy, the power grid urgently needs to develop large-scale flexible regulating power sources. Pumped storage power stations, as flexible regulating power sources with the most outstanding technical and economic advantages, are facing great difficulties in their development due to various factors such as terrain, water sources, and construction costs. The hybrid pumped storage (hybrid pumped storage) power station is built based on conventional cascade hydropower stations, taking into account the functions of pumped storage and runoff power generation. It has the advantages of low investment cost, short construction period, small reservoir flooding losses and environmental impact, and is an important way to improve the flexible regulation capacity of the power system. In addition, compared with traditional pumped storage power stations that generally only have daily regulation capabilities, hybrid pumped storage power stations based on large reservoir transformation have cross-day and even cross-season regulation capabilities, which can meet the long-term energy storage requirements of the power system.

[0003] However, traditional research on hybrid pumped storage power stations focuses on evaluating the impact of cascade hydropower energy storage transformation on hydropower's own power generation and peak-shaving benefits. In the context of new power system construction, it is urgent to explore the flexible regulation role of hybrid pumped storage power stations when they are jointly operated with wind power and photovoltaic energy. At present, the technology for the joint operation of hybrid pumped storage power stations and wind and solar energy is still in its infancy, including a short-term dispatching model for the joint operation of hybrid pumped storage power stations and wind power with the goal of maximizing economic benefits; and a cascade hydropower short-term peak-shaving optimization model containing hybrid pumped storage power stations, which analyzes the daily operation mode of hybrid pumped storage power stations and the main factors affecting their peak-shaving capacity. However, the above-mentioned existing technologies only focus on the daily regulation capacity of hybrid pumped storage power stations, and the water pumped up within a day will be emptied within the day. For hybrid pumped storage power stations built on reservoirs with seasonal or higher regulation performance, it is urgent to consider the water-wind-solar-storage complementary dispatching method of the seasonal regulation characteristics of hybrid pumped storage power stations, so as to achieve the long-term water storage and energy storage function of hybrid pumped storage power stations while improving the short-term peak-shaving benefits and the level of new energy consumption. Summary of the invention

[0004] The purpose of the present invention is to provide a water-wind-solar-storage complementary scheduling method taking into account the seasonal regulation characteristics of a hybrid pumped-storage power station, which can effectively solve the problems existing in the above-mentioned prior art.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solution: a water-wind-solar-storage complementary scheduling method considering the seasonal regulation characteristics of a hybrid pumped storage power station, comprising the following steps: S1. Add pumping stations between existing conventional cascade hydropower stations to establish hybrid pumped storage power stations, which include pumped storage and runoff power generation functions, and build the hybrid pumped storage power station together with the cascade hydro-wind-solar power stations to form a water-wind-solar-storage complementary system; S2. Construct a long-term and short-term nested scheduling model of water-wind-solar-storage complementary power plants considering the seasonal regulation characteristics of hybrid pumped storage power plants, and take the maximum power generation benefit as the model objective function; S3. Based on the dynamic programming successive approximation algorithm, a model solving method is constructed by introducing the pumped hydropower generation condition conversion model; S4. The long-term and short-term nested scheduling model of hydro-wind-solar-storage complementarity is solved by the constructed model solving method to obtain the hydro-wind-solar-storage complementary power generation plan with seasonal regulation characteristics of the hybrid pumped storage power station.

[0006] Preferably, in step S1, based on conventional cascade hydropower station reservoirs as upper and lower reservoirs, a hybrid pumped storage power station is formed by newly building a water transfer system and a pumping station; the scheduling principle of the water-wind-solar-storage multi-energy complementary system composed of the hybrid pumped storage power station and the cascade hydro-wind-solar power station is as follows: In order to ensure the minimum output of hydropower stations and the consumption of new energy, the priority of power transmission from different power sources is ranked from high to low as follows: the minimum output of conventional hydropower units, the output of new energy, and the adjustable output of conventional hydropower units; Hybrid pumped storage power stations give priority to using renewable energy to generate pumped storage energy. When renewable energy is generated and electricity is abandoned, hybrid pumped storage power stations pump water for energy storage under the premise of meeting water and electricity constraints. Secondly, they purchase electricity from the power grid to pump water during the period of low electricity prices. When the hybrid pumped-storage power station is in operation, conventional hydropower units operate at minimum output.

[0007] Preferably, in step S2, the model scheduling process includes a long-term scale and a short-term scale. The long-term scale takes the year as the scheduling period and the day as the scheduling period, considers the phased electricity price of wet and dry seasons, and takes the maximum annual power generation benefit as the model objective function; the short-term scale takes the day as the scheduling period and the hour as the scheduling period, and under the water level boundary constraints given by the long-term scheduling, considers the peak and valley time-of-use electricity prices, and takes the maximum daily power generation benefit as the model objective function.

[0008] Preferably, in step S2, the model objective function with maximum power generation benefit is specifically: ; ; ; ; ; ; ; in , are the long-term and d-day power generation benefits of the multi-energy complementary system respectively; D is the total long-term dispatch period; d is the d-day, d=1, 2, ..., D; T is the total short-term dispatch period; t is the t-hour, t=1, 2, ..., T; i is the i-th hydropower station, ; , , Respectively Hydropower station and access The power generation income of the wind power and photovoltaic power stations of the hydropower station at the t hour; The pumping costs for hybrid pumped storage plants; , , is the grid-connected power of the i-th hydropower station and the wind power and photovoltaic power stations connected to the i-th hydropower station at the tth hour; , , are the on-grid electricity prices of hydropower, wind power and photovoltaic power stations in period t; , are the pumping power purchased from the grid by the hybrid pumped-storage power station and the corresponding pumping electricity price; is the duration of the study period; , For the The output coefficient of the hydropower station and the The power generation flow during the period; , For the Hydropower Station No. Upstream reservoir water level and tailwater level during the period; , , are the pumping head, pumping flow and pumping efficiency of the hybrid pumped storage power station in the tth period respectively; The pumping power for the hybrid pumped-storage power station to absorb the internal electricity of the multi-energy complementary system.

[0009] Preferably, in step S2, constraints are also established in the model, and the constraints include water system constraints, power station output constraints and transmission channel capacity constraints.

[0010] Preferably, the water system constraints include: Water balance constraints: ; in, , They are The reservoir is in Initial and final storage capacity of the time period; is the interval inflow of the i-th reservoir in the t-th period; and Respectively The reservoir is in Power generation and water abandonment flows during the period; For the The collection of upstream reservoirs with which the reservoir has direct hydraulic connection; For the hybrid pumped storage power station Pumping flow rate during the period; is the state variable, when When the reservoir is the upper reservoir of a hybrid pumped storage power station, , when When the reservoir is the lower reservoir of a hybrid pumped storage power station, , when the i-th reservoir does not belong to the upper and lower reservoirs of the hybrid pumped storage power station, ; Water system constraints also include water level and storage capacity constraints: ; ; ; ; in, and respectively The reservoir is The water level in front of the dam and the tailwater level at the moment; is the functional relationship between the water level in front of the dam and the reservoir capacity; It represents the functional relationship between the discharge flow and the tailwater level; and They are The reservoir is in Initial and final storage capacity at a certain time; , It is The upper and lower limits of the storage capacity of the reservoir; and It represents the storage capacity of the reservoir at the beginning and end of the dispatch period; and is the storage capacity control boundary at the beginning and end of the scheduling period; Power generation flow constraints: ; For the The power generation flow of the turbine unit of the hydropower station at time t; For the The maximum permissible flow rate of the turbine units in the hydropower station; Reservoir discharge constraints: ; , It is The minimum and maximum discharge flow of the reservoir; For the The reservoir is in The amount of discarded water during the period.

[0011] Preferably, the power station output constraint is: ; ; ; ; ; in, , They are the wind and photovoltaic stations connected to the i-th hydropower station. Total output during the time period; and The wind and photovoltaic output consumed by the hybrid pumped storage power station; and They are The amount of power abandoned by wind power and photovoltaic power stations during the period; and represents the minimum and maximum output of the i-th hydropower station in period t; , , is the total power consumed by the hybrid pumped storage power station during period t, the pumping power used to absorb the excess power within the multi-energy complementary system, and the pumping power purchased from the grid; , is the minimum and maximum output of the hybrid pumped storage power station in period t.

[0012] Preferably, the transmission channel capacity constraint is: ; ; in, is the maximum transmission capacity of the power group, here it is the installed capacity of the hydropower station; It is Hydropower Stations The minimum output of a period is calculated based on the minimum downstream flow of the hydropower station.

[0013] Preferably, in step S3, the pumped power generation operating condition conversion model is introduced as follows: for power generation conditions, the power generation flow is not less than the minimum downstream flow; for pumping conditions, when wind and solar power are abandoned, priority is given to pumping and storing the abandoned wind and solar power, and the residual flow is obtained by deducting the minimum downstream flow according to the reservoir water balance formula in adjacent time periods. When the residual flow is negative, the corresponding part of the flow is used for pumping, otherwise it is used for power generation; when the first When the reservoir is the upper reservoir of a mixed storage power station, the residual flow is calculated as follows: ; in, For the Reservoirs in The remaining flow of the period, when When the corresponding part of the flow is used for power generation, When , the corresponding part of the flow is used for pumping; For the Reservoirs in Inbound flow during the time period; It is The minimum discharge flow of a reservoir.

[0014] Preferably, in step S4, the model solving method is specifically: The first step is to set the initial storage capacity of the cascade hydropower station during the entire dispatch period and enter the number of the currently optimized hydropower station. , each hydropower station corresponds to a reservoir, the number of iterations and power generation benefits The initial input values ​​of the parameters are , , , is a sufficiently small positive constant; The second step is to When the hybrid pumped storage power station is put on the reservoir, go to step 3, otherwise go to step 5; The third step is when When the dynamic programming algorithm is used to optimize The operation process of the hydropower station and its downstream hybrid pumped storage power station is shown in Figure 2. The constraints and power generation of other reservoirs are not considered in the initial iteration process. When the storage capacity of the remaining hydropower station reservoirs is fixed, the dynamic programming algorithm is used to optimize the The operation process of the hydropower station and its downstream hybrid pumped storage power station, and the optimization process combines the constraints and power generation of the remaining reservoirs; The fourth step is to set up the reservoir capacity process adjustment module to ensure that the cascade reservoir group meets the operation constraints in both pumping and power generation modes, and obtain the feasible capacity process of each reservoir. When , proceed to step 7. When, let ,like , proceed to step 5; The fifth step is to use the dynamic programming algorithm to optimize the first reservoir while keeping the storage capacity of other reservoirs unchanged. The storage capacity process of the reservoir of a large hydropower station.

[0015] Step 6: Let ,like , proceed to step 7, otherwise return to step 2; The seventh step is to solve the power generation flow of the hydropower station and the pumping flow of the hybrid pumped storage power station according to the optimized cascade reservoir storage capacity process, water balance and residual flow calculation formula, simulate the power generation and power consumption process of the cascade reservoir and hybrid pumped storage power station, and calculate the operating benefits of the multi-energy complementary system. , and set ,when or , indicating that the iterative calculation has not yet converged, let , return to step 2; otherwise, record and output the dispatching process of cascade hydropower stations and hybrid pumped-storage power stations.

[0016] Beneficial effects: (1) The present invention takes into account the seasonal regulation characteristics of the hybrid pumped storage power station, and establishes a long-term and short-term nested scheduling model of water-wind-solar-storage complementary power stations containing hybrid pumped storage power stations with the goal of maximizing operating benefits. In the short term, the wind and solar power abandonment and low-priced electricity can be used to achieve electricity time shifting and peak-valley price arbitrage. In the long term, part of the electricity can be transferred to the dry season with higher electricity prices by storing abundant electricity to make up for the dry season, thus giving full play to the incremental benefits brought by the transformation of cascade hydropower storage into a water-wind-solar-storage complementary system.

[0017] (2) The scheduling method proposed in the present invention that takes into account the seasonal regulation characteristics of the hybrid pumped-storage power station can provide additional flood control storage capacity for the downstream reservoirs by storing the excess water in the downstream to the upper reservoir with a larger storage capacity in advance, effectively improving the water abandonment phenomenon of the downstream small reservoirs, optimizing the seasonal allocation of water resources, and improving the flood control benefits of the cascade reservoirs.

[0018] (3) The solution of the complementary optimization scheduling process of water, wind, solar and storage including hybrid pumped storage power stations not only needs to determine the amount of water for power generation, but also increases the amount of water pumped by the pumping station, which increases the difficulty of solving the model. The present invention proposes an improved DPSA algorithm, which introduces the pumped power generation conversion model of the hybrid pumped storage power station into the DPSA algorithm for solution. The key is to judge the pumped power generation condition according to the operation status of the hybrid pumped storage power station and establish the connection between the pumped power generation variables, which can effectively reduce the number of variables and improve the calculation efficiency of the model.

[0019] The present invention provides technical support for the complementary dispatching operation of a water-wind-solar-storage complementary system including a hybrid pumped-storage power station, and can be used to guide the formulation of a power generation plan for the water-wind-solar-storage complementary system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0021] In the attached picture: Figure 1 It is a flow chart of the water-wind-solar-storage complementary scheduling method considering the seasonal regulation characteristics of the hybrid pumped-storage power station of the present invention; Figure 2 It is a structural schematic diagram of a water-wind-solar-storage complementary system including a hybrid pumped-storage power station.

[0022] Figure 3 It is a flow chart for solving the optimized dispatching of water-wind-solar-storage complementary system including a hybrid pumped-storage power station. DETAILED DESCRIPTION

[0023] The embodiments of the present invention are described below in conjunction with the drawings in the embodiments of the present invention. The terms used in the implementation mode of the present invention are only used to explain the specific embodiments of the present invention, and are not intended to limit the present invention. The embodiments of the present application are described below in conjunction with the drawings.

[0024] like Figure 1-Figure 3 As shown in FIG. 1 , the water-wind-solar-storage complementary scheduling method considering the seasonal regulation characteristics of the hybrid pumped storage power station includes the following steps: S1. Relying on seasonal regulation and above cascade hydropower stations, additional hybrid pumped storage power stations are built to construct a water-wind-solar-storage complementary system including seasonal regulation hybrid pumped storage power stations. Specifically, pumping stations are added between existing conventional cascade hydropower stations to establish hybrid pumped storage power stations. The hybrid pumped storage power stations include pumped storage and runoff power generation functions, and the hybrid pumped storage power stations are built together with cascade hydro-wind-solar power stations to form a water-wind-solar-storage complementary system. Hybrid pumped storage power station refers to a hybrid pumped storage power station that uses the existing conventional cascade hydropower station reservoirs as the upper and lower reservoirs, and forms a hybrid pumped storage power station with both runoff power generation and pumped storage functions through the construction of a new water transfer system and pumping station. Hybrid pumped storage power stations usually use a reservoir with large regulating capacity and good regulating performance as the upper reservoir, and a daily regulating or seasonal regulating reservoir as the lower reservoir, which can carry out energy storage regulation on a daily, weekly, monthly or even cross-seasonal scale.

[0025] The dispatching principles of the water-wind-solar-storage multi-energy complementary system consisting of a hybrid pumped storage power station and cascaded hydro-wind-solar power stations are as follows: In order to ensure the minimum output of hydropower stations and the absorption of new energy, the priority of power transmission from different power sources is arranged from high to low as follows: the minimum output of conventional hydropower units, new energy output, and adjustable output of conventional hydropower units.

[0026] Hybrid pumped-storage power stations give priority to the use of renewable energy to generate pumped storage energy, especially when large amounts of renewable energy are generated and electricity is wasted. Hybrid pumped-storage power stations pump storage energy under the premise of meeting hydraulic and electrical constraints. Secondly, they purchase electricity from the power grid to pump water during periods of low electricity prices.

[0027] Apart from the power generation flow that meets the minimum discharge requirement of the reservoir, due to the energy loss during the operation of the hybrid pumped storage power station, from the perspective of system economy and energy utilization efficiency, the pumped power generation conditions should not be operated at the same time, that is, when the hybrid pumped storage power station is in operation, the conventional hydropower units can only operate at the minimum output; refer to Figure 2 , the hybrid pumped storage power station transformed by the upper reservoir with seasonal regulation and above regulation capacity has the ability to regulate across seasons. Compared with the conventional water-wind-solar complementary system without a hybrid pumped storage power station, the hydraulic and electrical connection of the water-wind-solar-storage complementary system is more complex, forming a new water-energy coupling system: in terms of hydraulic connection, the hybrid pumped storage power station can pump water from the lower reservoir to the upper reservoir, so that the original one-way flow path from upstream to downstream is transformed into a two-way circulation loop between upstream and downstream; in terms of electrical connection, the hybrid pumped storage power station can use the surplus electricity of wind and solar energy and the low-priced electricity of the power grid to pump and store water, and release water to generate electricity during periods with higher electricity prices under the premise of meeting hydraulic and electrical constraints, and improve the new energy absorption capacity and system operation efficiency through time-shifting of electricity, so as to give full play to the incremental benefits of cascade hydropower storage transformation; S2. Considering the seasonal regulation characteristics of the hybrid pumped storage power station, a long-term and short-term nested scheduling model of water, wind, solar and storage complementarity is established with the goal of maximizing power generation benefits. Specifically, a long-term and short-term nested scheduling model of water, wind, solar and storage complementarity is established with the seasonal regulation characteristics of the hybrid pumped storage power station, and the maximum power generation benefits are taken as the model objective function; The model scheduling process includes long-term and short-term scales. The long-term scale takes the year as the scheduling period and the day as the scheduling period, considers the phased electricity price of wet and dry seasons, and takes the maximum annual power generation benefit as the model objective function; the short-term scale takes the day as the scheduling period and the hour as the scheduling period, and takes the peak and valley time-of-use electricity price as the scheduling period under the water level boundary constraints given by the long-term scheduling, and takes the maximum daily power generation benefit as the model objective function.

[0028] Taking the maximum power generation benefit as the model objective function, the specific model objective function is: ; ; ; ; ; ; ; in , are the long-term and d-day power generation benefits of the multi-energy complementary system respectively; D is the total long-term dispatch period; d is the d-day, d=1, 2, ..., D; T is the total short-term dispatch period; t is the t-hour, t=1, 2, ..., T; i is the i-th hydropower station, ; , , Respectively The power generation income of the hydropower station and the wind power and photovoltaic power stations connected to the i-th hydropower station at the tth hour; The pumping costs for hybrid pumped storage plants; , , For the Hydropower station and access The grid-connected power of the wind power and photovoltaic power stations of the hydropower station at the t hour; , , are the on-grid electricity prices of hydropower, wind power and photovoltaic power stations in period t; , are the pumping power purchased from the grid by the hybrid pumped-storage power station and the corresponding pumping electricity price; is the duration of the study period; , For the The output coefficient of the hydropower station and the The power generation flow during the period; , For the Hydropower Station No. Upstream reservoir water level and tailwater level during the period; , , Hybrid pumped storage power station Pumping head, pumping flow, and pumping efficiency during each period; The pumping power for the hybrid pumped-storage power station to absorb the internal electricity of the multi-energy complementary system.

[0029] Constraints are also set up in the model, including water system constraints, power station output constraints and transmission channel capacity constraints; Water system constraints include: Water balance constraints: ; in, , They are The reservoir is in Initial and final storage capacity of the time period; For the i-th reservoir in The interval inflow flow within the time period; and Respectively The reservoir is in Power generation and water abandonment flows during the period; For the The collection of upstream reservoirs with which the reservoir has direct hydraulic connection; For the hybrid pumped storage power station Pumping flow rate during the period; is the state variable, when When the reservoir is the upper reservoir of a hybrid pumped storage power station, , when When the reservoir is the lower reservoir of a hybrid pumped storage power station, , when When the reservoir is not the upper or lower reservoir of a hybrid pumped storage power station, ; Water system constraints also include water level and storage capacity constraints: ; ; ; ; in, and respectively The reservoir is The water level in front of the dam and the tailwater level at the moment; is the functional relationship between the water level in front of the dam and the reservoir capacity; It represents the functional relationship between the discharge flow and the tailwater level; and They are The initial and final storage capacity of a reservoir at time t; , It is The upper and lower limits of the storage capacity of the reservoir; and It represents the storage capacity of the reservoir at the beginning and end of the dispatch period; and is the storage capacity control boundary at the beginning and end of the scheduling period; Power generation flow constraints: ; For the The power generation flow of the turbine unit of the hydropower station at time t; For the The maximum permissible flow rate of the turbine units in the hydropower station; Reservoir discharge constraints: ; , It is The minimum and maximum discharge flow of the reservoir; For the The water discharge of a reservoir in period t.

[0030] The power station output constraint is: ; ; ; ; ; in, , Access The wind and photovoltaic stations of the hydropower station Total output during the time period; and The wind and photovoltaic output consumed by the hybrid pumped storage power station; and They are The amount of power abandoned by wind power and photovoltaic power stations during the period; and Indicates Hydropower Station Minimum and maximum output of the time period; , , is the total power consumed by the hybrid pumped storage power station during period t, the pumping power used to absorb the excess power within the multi-energy complementary system, and the pumping power purchased from the grid; , Hybrid pumped storage power station The minimum and maximum output of the time period.

[0031] The transmission channel capacity constraint is: ; ; in, is the maximum transmission capacity of the power group, here it is the installed capacity of the hydropower station; It is Hydropower Stations The minimum output of a period is calculated based on the minimum downstream flow of the hydropower station.

[0032] S3. Introducing the pumped-hydro power generation operating condition conversion model, an improved dynamic programming successive approximation solution method is proposed, specifically: based on the dynamic programming successive approximation algorithm, and introducing the pumped-hydro power generation operating condition conversion model to construct a model solution method; In order to avoid the "curse of dimensionality" caused by too many decision variables, the dynamic programming successive approximation algorithm (DPSA) can be used for solution. According to the principle that pumped power generation conditions cannot be operated simultaneously (ignoring the situation of power generation with the minimum downstream flow), the pumped power generation flow of the system is calculated, and the pumped power generation condition conversion model is introduced. Specifically: for power generation conditions, the power generation flow is not less than the minimum downstream flow; for pumped conditions, when wind and solar power are abandoned, priority is given to pumping and storing the abandoned wind and solar power. The residual flow is obtained by deducting the minimum downstream flow according to the reservoir water balance formula in adjacent time periods. When the residual flow is negative, the corresponding part of the flow is used for pumping, otherwise it is used for power generation; when the first When the reservoir is the upper reservoir of a mixed storage power station, the residual flow is calculated as follows: ; in, For the Reservoirs in The remaining flow of the period, when When the corresponding part of the flow is used for power generation, When , the corresponding part of the flow is used for pumping; For the i-th reservoir Inbound flow during the time period; It is The minimum outflow rate of the reservoir; S4. Solve the long-term and short-term nested scheduling model of water-wind-solar-storage complementary power generation with the constructed model solving method to obtain the water-wind-solar-storage complementary power generation plan with seasonal regulation characteristics of the hybrid pumped storage power station; The first The hydropower station and its downstream hybrid pumped storage power station are considered as a whole for calculation, with wind and solar power output, reservoir runoff, reservoir capacity control boundary, and time-of-use electricity price data as inputs. The model decision variable is the reservoir water storage capacity. The model solution method is as follows: The first step is to set the initial storage capacity of the cascade hydropower station during the entire dispatch period and enter the number of the currently optimized hydropower station. , each hydropower station corresponds to a reservoir, the number of iterations and power generation benefits The initial input values ​​of the parameters are , , , is a sufficiently small positive number; The second step is to When the hybrid pumped storage power station is put on the reservoir, go to step 3, otherwise go to step 5; The third step is when When the dynamic programming algorithm is used to optimize The operation process of the hydropower station and its downstream hybrid pumped storage power station is shown in Figure 2. The constraints and power generation of other reservoirs are not considered in the initial iteration process. When the storage capacity of the remaining hydropower station reservoirs is fixed, the dynamic programming algorithm is used to optimize the The operation process of the hydropower station and its downstream hybrid pumped storage power station, and the optimization process combines the constraints and power generation of the remaining reservoirs; The fourth step is to set up the reservoir capacity process adjustment module to ensure that the cascade reservoir group meets the operation constraints in both pumping and power generation modes, and obtain the feasible capacity process of each reservoir. When , proceed to step 7. When, let ,like , proceed to step 5; The fifth step is to use the dynamic programming algorithm to optimize the first reservoir while keeping the storage capacity of other reservoirs unchanged. The storage capacity process of the reservoir of a hydropower station.

[0033] Step 6: Let ,like , proceed to step 7, otherwise return to step 2; The seventh step is to solve the power generation flow of the hydropower station and the pumping flow of the hybrid pumped storage power station according to the optimized cascade reservoir storage capacity process, water balance and residual flow calculation formula, simulate the power generation and power consumption process of the cascade reservoir and hybrid pumped storage power station, and calculate the operating benefits of the multi-energy complementary system. , and set ,when or , indicating that the iterative calculation has not yet converged, let , return to step 2; otherwise, record and output the dispatching process of cascade hydropower stations and hybrid pumped-storage power stations.

[0034] In a specific embodiment, the Hongjiadu-Dongfeng-Suofengying cascade water-wind-solar complementary system in the Wujiang River Basin is taken as an example, and the water-wind-solar-storage complementary scheduling model and method considering the seasonal regulation characteristics of the hybrid pumped storage power station are used for analysis. The system includes 1895 MW of hydropower, 929 MW of wind power, and 1950 MW of photovoltaic power. Among them, the Hongjiadu Reservoir, as the leading reservoir in the Wujiang River Basin, has multi-year regulation characteristics, and the lower Dongfeng Reservoir and Suofengying Reservoir have seasonal regulation and daily regulation capabilities respectively. A hybrid pumped storage power station is constructed by adding a 340 MW pump station between the first-level Hongjiadu and the second-level Dongfeng power stations. The system characteristic parameters and the access to the wind and solar power stations are shown in Table 1.

[0035] Table 1 Parameters of Hongjiadu-Dongfeng-Suofengyingshui wind and solar power station

[0036] In order to evaluate the impact of the water-wind-solar-storage complementary scheduling method with seasonal regulation characteristics of hybrid pumped storage power stations on the scheduling process and operation benefits of the multi-energy complementary system, multi-energy complementary scheduling schemes without hybrid pumped storage, hybrid pumped storage daily regulation, and hybrid pumped storage seasonal regulation are set respectively: 1) No hybrid pumped storage: For the conventional water-wind-solar complementary system before the cascade hydropower storage transformation, the installed capacity of the hybrid pumped storage power station is 0; 2) Hybrid pumped storage daily regulation: The multi-energy complementary system consists of a hybrid pumped storage power station, cascade hydropower and wind-solar power stations. The regulation effect of the hybrid storage power station is not considered in the long-term scale. The water pumped up within a day will be emptied within the day. Therefore, the long-term water level process of the scheme without hybrid pumped storage is taken as the daily water level boundary of this scheme; 3) Hybrid pumped storage seasonal regulation: The water-wind-solar-storage complementary scheduling method considering the seasonal regulation characteristics of the hybrid pumped storage power station described in the present invention. The scheduling results of the three schemes are shown in Table 2.

[0037] Table 2 Scheduling results of multi-energy complementary system under different scheduling schemes

[0038] The application results show that the method of the invention can realize price arbitrage by utilizing the abandoned power of renewable energy and low-priced power in the short term, and increase the available water volume in the dry season by storing abundant water and making up for the shortage in the long term. Compared with the non-hybrid pumped storage scheme, it can effectively reduce the abandoned power of renewable energy (-99%), increase the power generation efficiency of the system (+4.20%), and reduce the abandoned water of cascade reservoirs (-95%); compared with the hybrid pumped storage daily regulation scheme, it can increase the power generation in the dry season and increase the comprehensive energy conversion efficiency of the system (+5.43%).

[0039] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. For ordinary technicians in this technical field, after knowing the contents recorded in the present invention, they can make several equivalent changes and substitutions without departing from the principle of the present invention. These equivalent changes and substitutions should also be regarded as belonging to the protection scope of the present invention.

Claims

1. A water-wind-solar-storage complementary scheduling method considering the seasonal regulation characteristics of a hybrid pumped storage power station, characterized in that: The steps include: S1. Add pumping stations between existing conventional cascade hydropower stations to establish hybrid pumped storage power stations, which include pumped storage and runoff power generation functions, and build the hybrid pumped storage power station together with the cascade hydro-wind-solar power stations to form a water-wind-solar-storage complementary system; S2. Construct a long-term and short-term nested scheduling model of water-wind-solar-storage complementary power plants considering the seasonal regulation characteristics of hybrid pumped storage power plants, and take the maximum power generation benefit as the model objective function; S3. Based on the dynamic programming successive approximation algorithm, a model solving method is constructed by introducing the pumped hydropower generation condition conversion model; S4. The long-term and short-term nested scheduling model of hydro-wind-solar-storage complementarity is solved by the constructed model solving method to obtain the hydro-wind-solar-storage complementary power generation plan with seasonal regulation characteristics of the hybrid pumped storage power station.

2. The water-wind-solar-storage complementary scheduling method considering the seasonal regulation characteristics of the hybrid pumped storage power station according to claim 1 is characterized by: In step S1, based on the conventional cascade hydropower station reservoirs as the upper and lower reservoirs, a hybrid pumped storage power station is formed by newly building a water transfer system and a pumping station; the scheduling principle of the water-wind-solar-storage multi-energy complementary system composed of the hybrid pumped storage power station and the cascade hydro-wind-solar power station is as follows: In order to ensure the minimum output of hydropower stations and the consumption of new energy, the priority of power transmission from different power sources is ranked from high to low as follows: the minimum output of conventional hydropower units, the output of new energy, and the adjustable output of conventional hydropower units; Hybrid pumped storage power stations give priority to using renewable energy to generate pumped storage energy. When renewable energy is generated and electricity is abandoned, hybrid pumped storage power stations pump water for energy storage under the premise of meeting water and electricity constraints. Secondly, they purchase electricity from the power grid to pump water during the period of low electricity prices. When the hybrid pumped-storage power station is in operation, conventional hydropower units operate at minimum output.

3. The water-wind-solar-storage complementary scheduling method considering the seasonal regulation characteristics of the hybrid pumped storage power station according to claim 1 is characterized in that: In step S2, the model scheduling process includes long-term and short-term scales. The long-term scale takes the year as the scheduling period and the day as the scheduling period, considers the phased electricity price of wet and dry seasons, and takes the maximum annual power generation benefit as the model objective function; the short-term scale takes the day as the scheduling period and the hour as the scheduling period, and under the water level boundary constraints given by the long-term scheduling, considers the peak and valley time-of-use electricity price, and takes the maximum daily power generation benefit as the model objective function.

4. The water-wind-solar-storage complementary scheduling method considering the seasonal regulation characteristics of the hybrid pumped storage power station according to claim 3 is characterized by: In step S2, the model objective function is to maximize the power generation benefit: ； ； ； ； ； ； ； in , are the long-term and d-day power generation benefits of the multi-energy complementary system respectively; D is the total long-term dispatch period; d is the d-day, d=1, 2,…, D; T is the total period of short-term scheduling; t is the tth hour, t=1, 2, …, T; i is the i-th hydropower station, ; , , Respectively Hydropower station and access The power generation income of the wind power and photovoltaic power stations of the hydropower station at the t hour; The pumping costs for hybrid pumped storage plants; , , For the The grid-connected power of the hydropower station and the wind power and photovoltaic power station connected to the i-th hydropower station at the tth hour; , , are the on-grid electricity prices of hydropower, wind power and photovoltaic power stations in period t; , are the pumping power purchased from the grid by the hybrid pumped-storage power station and the corresponding pumping electricity price; is the duration of the study period; , is the output coefficient of the i-th hydropower station and the The power generation flow during the period; , is the upstream reservoir water level and tailwater level of the i-th hydropower station in the t-th period; , , are the pumping head, pumping flow and pumping efficiency of the hybrid pumped storage power station in the tth period respectively; The pumping power for the hybrid pumped-storage power station to absorb the internal electricity of the multi-energy complementary system.

5. The water-wind-solar-storage complementary scheduling method considering the seasonal regulation characteristics of the hybrid pumped storage power station according to claim 1 is characterized in that: In step S2, constraints are also established in the model, and the constraints include water system constraints, power station output constraints and transmission channel capacity constraints.

6. The water-wind-solar-storage complementary scheduling method considering the seasonal regulation characteristics of the hybrid pumped storage power station according to claim 5 is characterized in that: The water system constraints include: Water balance constraints: ； in, , The i-th reservoir is Initial and final storage capacity of the time period; is the interval inflow of the i-th reservoir in the t-th period; and are the i-th reservoir in the Power generation and water abandonment flows during the period; is the set of upstream reservoirs that have direct hydraulic connection with the i-th reservoir; is the pumping flow of the hybrid pumped storage power station in the tth period; k is the state variable. When the reservoir is the upper reservoir of a hybrid pumped storage power station, , when When the reservoir is the lower reservoir of a hybrid pumped storage power station, , when When the reservoir is not the upper or lower reservoir of a hybrid pumped storage power station, .

7. The water-wind-solar-storage complementary scheduling method considering the seasonal regulation characteristics of the hybrid pumped storage power station according to claim 1 is characterized by: In step S3, the pumped power generation condition conversion model is introduced as follows: for power generation conditions, the power generation flow is not less than the minimum downstream flow; for pumping conditions, when wind and solar power are abandoned, priority is given to pumping to store the abandoned wind and solar power, and the residual flow is obtained by deducting the minimum downstream flow according to the reservoir water balance formula in adjacent time periods. When the residual flow is negative, the corresponding part of the flow is used for pumping, otherwise it is used for power generation; when the first When the reservoir is the upper reservoir of a mixed storage power station, the residual flow is calculated as follows: ； in, For the Reservoirs in The remaining flow of the period, when When the corresponding part of the flow is used for power generation, When , the corresponding part of the flow is used for pumping; For the Reservoirs in Inbound flow during the time period; It is The minimum discharge flow of a reservoir.

8. The water-wind-solar-storage complementary scheduling method considering the seasonal regulation characteristics of the hybrid pumped storage power station according to claim 5 is characterized by: In step S4, the model solving method is specifically as follows: The first step is to set the initial storage capacity of the cascade hydropower station during the entire dispatch period and enter the number of the currently optimized hydropower station. , number of iterations and power generation benefits The initial input values ​​of the parameters are , , , is a positive constant; The second step is to When the hybrid pumped storage power station is put on the reservoir, go to step 3, otherwise go to step 5; The third step is when When the dynamic programming algorithm is used to optimize The operation process of the hydropower station and its downstream hybrid pumped storage power station is shown in Figure 2. The constraints and power generation of other reservoirs are not considered in the initial iteration process. When the storage capacity of the remaining hydropower station reservoirs is fixed, the dynamic programming algorithm is used to optimize the The operation process of the hydropower station and its downstream hybrid pumped storage power station, and the optimization process combines the constraints and power generation of the remaining reservoirs; The fourth step is to set up the reservoir capacity process adjustment module to ensure that the cascade reservoir group meets the operation constraints in both pumping and power generation modes, and obtain the feasible capacity process of each reservoir; When , proceed to step 7. When, let ,like , proceed to step 5; The fifth step is to use the dynamic programming algorithm to optimize the first reservoir while keeping the storage capacity of other reservoirs unchanged. The storage capacity process of the reservoir of a hydropower station; Step 6: Let ,like , proceed to step 7, otherwise return to step 2; The seventh step is to solve the power generation flow of the hydropower station and the pumping flow of the hybrid pumped storage power station according to the optimized cascade reservoir storage capacity process, water balance and residual flow calculation formula, simulate the power generation and power consumption process of the cascade reservoir and hybrid pumped storage power station, and calculate the operating benefits of the multi-energy complementary system. , and set ,when or , indicating that the iterative calculation has not yet converged, let , return to step 2; otherwise, record and output the dispatching process of cascade hydropower stations and hybrid pumped-storage power stations.

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