Configuration method for pumped storage power station of provincial power system based on NNC-MILP method

Abstract

The invention discloses a provincial power system pumped storage power station configuration method based on an NNC-MILP method, and belongs to the technical field of pumped storage power station configuration. Comprising the steps that S1, a peak regulation demand model is constructed based on provincial power system composition equipment, and the peak regulation demand model is used for obtaining a planning target annual peak regulation demand evaluation result; s2, constructing a pumped storage power station power-capacity configuration model, and constructing a dual-objective function based on the pumped storage power-capacity configuration model and the peak regulation demand model; solving the dual-objective function by adopting an NNC method to obtain a dual-objective configuration scheme; and S3, measuring and calculating the suppression effect of the power abandoning time and the power shortage time of the pumped storage power station after configuration based on the double-target configuration scheme and the return-on-investment ratio to obtain a final energy storage configuration scheme. According to the method, the power abandoning / shortage, the duration, the peak value, the power abandoning / shortage time sequence distribution, the power abandoning / shortage coverage and the alternating condition are comprehensively considered, and the annual peak regulation demand of the planning target is accurately depicted.

Description

Technical Field

[0001] This invention belongs to the field of pumped storage power station configuration technology, specifically relating to a provincial power system pumped storage power station configuration method based on the NNC-MILP method. Background Technology

[0002] In characterizing peak-shaving demand, existing typical daily clustering methods approximate the annual sequence with a small number of representative curves. These methods have low computational overhead and are convenient for scenario extrapolation, but they struggle to cover extreme weather, long-memory correlations, and cross-seasonal coupling, and are prone to underestimating the demand gap. Annual time-series simulation methods start and stop units based on cost or priority, reflecting seasonal and intraday differences. However, without embedding physical conditions such as ramp-up constraints, minimum start-up and shutdown times, and standby linkage, the assessment tends to be overly optimistic. Probabilistic and scenario tree methods can characterize output and load uncertainties and improve robustness; however, the increasing number of scenarios, the complexity of correlation modeling, and the heavy solution burden limit their application on large-scale annual data. Demand-side profiling still needs to achieve a better balance between annual time-series accuracy, unit physical consistency, and computability to directly support engineering-level decision-making.

[0003] In terms of peak-shaving resource allocation, research on pumped storage encompasses stochastic programming, robust programming, multi-timescale stratified and rolling optimization, and site selection decisions with hydrological constraints. Stochastic programming based on typical daily data is efficient, but its adaptability to cross-seasonal extremes and peak-valley migration is limited. Robust programming can guarantee feasibility under adverse conditions, but the trade-off between conservatism and benefits still needs to be refined. Incorporating spatial distribution of water resources, natural water inflow processes, and topographic conditions can improve engineering feasibility and operational safety, but its coupling with electricity market mechanisms, reserve demand, and intra-annual temporal characteristics remains insufficient. Stratified and rolling strategies facilitate the connection between day-ahead and real-time conditions, but they are prone to computational bottlenecks in high-dimensional scenarios. Some works introduce the synergy of pumped storage with electrochemical energy storage and demand response, which can enhance system flexibility and renewable energy absorption capacity; however, simplifications are still needed in key aspects such as power and reservoir capacity coupling, daily or cyclical status, start-up and ramp-up of conventional units, and reserve levels. Economic evaluations often focus on single indicators, making it difficult to comprehensively reflect the combined performance of long-term investment and daily operation. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a configuration method for pumped storage power stations in provincial power systems based on the NNC-MILP method. This method covers models such as peak-shaving demand characterization, optimal power / capacity configuration schemes for pumped storage power stations, and calculation of peak-shaving benefits and return on investment of the configuration schemes.

[0005] To achieve the above objectives, the present invention provides the following solution: a method for configuring pumped storage substations in a provincial power system based on the NNC-MILP method, comprising the following steps: S1. Construct a peak-shaving demand model based on the components of the provincial power system. The peak-shaving demand model is used to obtain the peak-shaving demand assessment results for the planned target year. S2. Construct a pumped storage power-capacity configuration model based on the mixed integer linear programming method, and construct a dual objective function based on the pumped storage power-capacity configuration model and the peak-shaving demand model; solve the dual objective function using the NNC method to obtain the dual objective configuration scheme; S3. Calculate the effect of suppressing power curtailment and power shortage time and the return on investment of the pumped storage power station after configuration based on the dual-objective configuration scheme to obtain the final energy storage configuration scheme.

[0006] More preferably, the peak-shaving demand assessment results for the planned target year include: abandoned power, power shortage, abandoned power, power shortage power, abandoned power duration, power shortage duration, peak value, time-series distribution, and coverage and alternation status; The methods for obtaining the abandoned power, the shortage power, the abandoned power, and the shortage power include: ; ; ; In the formula, Indicates the net load of the regional power system; For electrical load; , The power in wind power maximum power point tracking mode and the power in solar power maximum power point tracking mode; , These represent the power curtailment and power shortage of the regional power system, respectively. , These represent the amount of abandoned electricity and the amount of electricity shortage in the regional power system, respectively. Indicates the total number of time periods in the configuration model; , , These represent the installed capacity of pumped storage power stations, thermal power units, and gas turbine units, respectively. , This indicates the curtailment rate and power shortage rate of the regional power system.

[0007] More preferably, the pumped storage power station power-capacity configuration model includes: a pumped storage power station cost model, a pumped storage power-capacity coupling constraint, and a pumped storage power station daily clearing constraint; The power-capacity coupling constraints of the pumped storage power station include: ; ; in, ; In the formula, , This refers to the rated installed power and rated installed capacity of the pumped storage power station. , They are respectively t The pumped storage power station displays both its power generation and pumping status indicators at all times. Power generation capacity; For real-time power storage; This is the lower limit of the charge capacity of pumped storage power stations; , These are the power generation operating efficiency and the pumping operating efficiency, respectively. This represents the time granularity of the model.

[0008] More preferably, the dual objective function includes: a social power supply cost objective function and a social power supply violation event objective function; The objective function F1 for minimizing the social cost of electricity includes: ; In the formula, The social power supply cost after configuring pumped storage power stations in the planned target year; , Costs of wind power generation and photovoltaic power generation; , , Costs of hydropower generation, thermal power generation, and gas-fired power generation; , Costs related to demand response and load shedding; As a penalty for abandoning electricity; This covers the investment, construction, operation, and maintenance costs of pumped storage power stations; This represents the total investment cost over the entire life cycle of a pumped storage power station. The objective function F2 for minimizing social power supply violation events includes: ; In the formula, This refers to the total annual amount of electricity wasted and the total amount of electricity shortage. This refers to the load shedding power.

[0009] More preferably, the method for calculating the effect of the configured pumped-storage power station on suppressing power curtailment and power shortage time includes: ; ; In the formula, , To configure the power curtailment before and after the pumped storage power station; , To configure the power shortage before and after the pumped storage power station; , To determine the changes in annual abandoned and shorted electricity before and after configuring pumped storage power stations; , To measure the changes in annual curtailment rate and power shortage rate before and after configuring pumped storage power stations.

[0010] More preferably, the method for calculating the return on investment of the pumped-storage power station includes: ; In the formula, , To determine the annual comprehensive operating costs before and after configuring the pumped storage power station; To determine the annual net profit of the pumped storage power station; To determine the return on investment for pumped storage power stations.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention comprehensively considers the amount of power curtailment / shortage, duration, peak value, timing distribution of curtailment / shortage, coverage, and alternation of curtailment / shortage to accurately characterize the peak-shaving demand for the planned target year. In the MATLAB / Gurobi environment, with the dual objectives of minimizing overall power supply cost and curtailment / shortage, it comprehensively considers unit start-up / ramp-up constraints, operating efficiency and boundary constraints, power-capacity coupling, and daily clearing constraints to determine the configuration capacity and power / capacity ratio of pumped-storage power stations for the planned target year.

[0012] This invention uses data from a provincial power system as a case study to verify that after the planned annual expenditure of 1.477 billion yuan to configure a 4.25 million kW / 8h pumped storage power station, it participates in peak shaving for 3,991 hours a year, resulting in a reduction of abandoned / deficient electricity by 44.65% / 64.09%, a reduction of 4.803 billion yuan in annual system operating costs, and a return on investment of up to 325%, demonstrating economic feasibility and significant peak shaving benefits. Attached Figure Description

[0013] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the regional power system equipment architecture used in an embodiment of the present invention; Figure 2 A schematic diagram of the technical framework for the configuration method of pumped storage power stations in a provincial power system based on the NNC-MILP method provided in this embodiment of the invention; Figure 3This is a schematic diagram of the dual-target NNC method used in an embodiment of the present invention; Figure 4 A schematic diagram of historical annual wind power generation, photovoltaic power generation, and load power time series curves provided for embodiments of the present invention; Figure 5 This invention provides a schematic diagram of power curtailment / shortage in the power system in the area before the configuration of a pumped storage power station, as provided in an embodiment of the invention. (a) is a schematic diagram of the annual time-series production simulation of the power system in the area before the configuration of a pumped storage power station; (b) is a schematic diagram of the annual time-series production simulation ranking results of the power system in the area before the configuration of a pumped storage power station; (c) is a schematic diagram of the analysis results of power curtailment / shortage phenomena in the power system in the area before the configuration of a pumped storage power station; and (d) is a schematic diagram of the analysis results of power curtailment / shortage phenomena in the power system in the area before the configuration of a pumped storage power station. Figure 6 This is a schematic diagram of the power balance analysis results for a typical scenario of power curtailment / shortage before configuring a pumped storage power station, provided in an embodiment of the present invention. Figure 7 This is a schematic diagram of the multi-objective Pareto front curves for three schemes provided in the embodiments of the present invention; Figure 8 A schematic diagram showing the selected optimal configuration pumped storage power-capacity value results provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the regional power system operation status after configuring a pumped storage power station, provided in an embodiment of the present invention; wherein, (a) is a schematic diagram of the annual time-series production simulation of the system after configuring a pumped storage power station; and (b) is a schematic diagram of the annual time-series production simulation ranking results of the system after configuring a pumped storage power station. Figure 10 A schematic diagram illustrating the power curtailment / shortage results analysis of the regional power system after configuring a pumped storage substation, as provided in an embodiment of the present invention. Figure 11 This is a schematic diagram of the annual pumped storage charging / discharging results after configuring a pumped storage power station, provided in an embodiment of the present invention. Figure 12 The diagram below shows the system operation status analysis results for a typical week after configuring a pumped storage power station, as provided in the embodiments of the present invention. (a) is a schematic diagram of the power balance analysis results for a typical week after configuring a pumped storage power station; (b) is a schematic diagram of the pumped storage charging / discharging power for a typical week after configuring a pumped storage power station; and (c) is a schematic diagram of the change in the charge status of the pumped storage power station for a typical week after configuring a pumped storage power station. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] Example 1: like Figure 2 As shown, this embodiment provides a method for configuring pumped storage substations in a provincial power system based on the NNC-MILP method, including the following steps: S1. Construct a peak-shaving demand model based on the components of the provincial power system, and obtain the peak-shaving demand assessment results for the planned target year based on the peak-shaving demand model. like Figure 1 As shown, the provincial power system includes wind power, photovoltaic (solar), hydropower, thermal power, gas-fired power plants, pumped storage power stations, and load demand response units. The peak-shaving demand model includes models for wind power, photovoltaic, hydropower, thermal power, gas-fired power, and load demand response operation constraints.

[0018] In the context of conventional unit operation and system power balance constraints, this embodiment adopts the method provided in the literature: Zhang Junhua, Guo Xinyi, Zhao Zhenyu, et al. Frequency characteristic analysis of wind-solar-thermal-storage combined system considering new energy uncertainty [J]. Acta Energiae Solaris Sinica, 2025, 46(12): 437-447, to model the operation constraints of wind power, photovoltaic, hydropower, thermal power, gas, and load demand response.

[0019] Load demand response and load shedding modeling are as follows: (1) In the formula, , The ratio of demand response to load shedding within the provincial power system; For electrical load; , These are demand response and load shedding power, respectively.

[0020] Regional power system power balance constraints include: (2) In the formula, , The power in wind power maximum power point tracking mode and the power in solar power maximum power point tracking mode; , , This refers to the power output of hydroelectric power plants, thermal power plants, and gas-fired power plants. , This refers to the curtailment of wind and solar power in the provincial power system. This indicates the pumping power.

[0021] Net load describes the difference between the total load of the power system and the output of renewable energy sources such as wind and solar power, and intuitively reflects the supply pressure of conventional regulating power sources. When the net load is negative, it indicates an oversupply of new energy sources, which may lead to power curtailment due to limitations in system regulation capacity; conversely, if the peak net load exceeds the upper limit of power source regulation, it will lead to a power supply shortage.

[0022] (3) (4) (5) In the formula, Indicates the net load of the regional power system; , These represent the power curtailment and power shortage of the regional power system, respectively. , These represent the amount of abandoned electricity and the amount of electricity shortage in the regional power system, respectively. Indicates the total number of time periods in the configuration model; , , These represent the installed capacity of pumped storage power stations, thermal power units, and gas turbine units, respectively. , This indicates the amount of abandoned or insufficient power in the regional power system.

[0023] Through the above steps, we obtain the amount of power abandoned, the amount of power short, the power of power abandoned, and the power of power short in peak shaving demand. Peak shaving demand also includes the duration of power abandonment / shortage, peak value, time sequence distribution, coverage, and alternation.

[0024] S2. Construct a pumped storage power-capacity configuration model, and build a dual objective function based on the pumped storage power-capacity configuration model and the peak-shaving demand model; use the NNC method to solve the dual objective function to obtain the dual objective configuration scheme.

[0025] The pumped storage power-capacity configuration model includes: the cost model of the pumped storage power station, the power-capacity coupling constraints of the pumped storage power station, and the daily clearing constraints of the pumped storage power station; the construction of a pumped storage power station involves multiple engineering and equipment investments, and the cost model of the pumped storage power station includes: (6) In the formula, For civil engineering costs; For the cost of electrical equipment; Cost of speed regulation and control systems; For environmental protection and social costs; Fixed costs for configuring pumped storage power stations; This represents the investment cost over the entire life cycle of a pumped storage power station.

[0026] The investment cost over the entire life cycle of the pumped storage power station is spread across the annualized cost: (7) In the formula, This refers to the amount that needs to be repaid each year. The annual interest rate; This refers to the number of repayment periods.

[0027] The power-capacity coupling constraints of pumped storage power stations include: (8) (9) in, ; (10) In the formula, This refers to the rated installed capacity of the pumped storage power station. , They are respectively t The pumped storage power station displays both its power generation and pumping status indicators at all times. Power generation capacity; Store electricity at time t; This is the lower limit of the charge capacity of pumped storage power stations; , These are the power generation operating efficiency and the pumping operating efficiency, respectively. This represents the time granularity of the model.

[0028] Daily clearing constraints for pumped storage power stations require that their energy storage state be restored to its initial level at the end of each daily dispatch cycle to ensure the integrity and controllability of the pumped storage power station's cyclic operation. Daily clearing constraints include: (11) In the formula, , These represent the initial and final charge volumes of the pumped storage power station, respectively.

[0029] The dual objective functions include: minimizing the social cost of electricity supply and minimizing social electricity supply violation events.

[0030] The objective function F1 for minimizing the social cost of electricity includes: (12) In the formula, The social power supply cost after configuring pumped storage power stations in the planned target year; , Costs of wind power generation and photovoltaic power generation; , , Costs of hydropower generation, thermal power generation, and gas-fired power generation; , Costs related to demand response and load shedding; As a penalty for abandoning electricity; This refers to the investment, construction, operation, and maintenance costs of pumped storage power stations.

[0031] The objective function F2 for minimizing social power supply violation events includes: (13) In the formula, This refers to the total annual amount of electricity wasted and the total amount of electricity in short supply.

[0032] It is solved using the Normalized Normal Constraint (NNC) method: (14) In the formula, and These represent the inequality constraints and equality constraints of the provincial power system pumped storage capacity allocation strategy, respectively, namely the constraint formulas provided above in this embodiment. This represents the set of variables within a bi-objective configuration scheme.

[0033] like Figure 3 The diagram shows a two-objective NNC method. NNC divides the feasible region by introducing normal constraints, transforming a multi-objective problem into a single-objective problem. The specific process is as follows: (1) Taking the objective function F1 that minimizes the social power supply cost as the sole objective function, solve for the anchor point coordinates. : (15) (2) Taking the objective function F2 of minimizing the social power supply violation event as the sole objective function, solve for the anchor point coordinates. : (16) (3) Normalize the solution set, and normalize the two extreme points to the normalized values. and : (17) (4) Divide the line segment connecting the coordinates of the two extreme points into equal parts to obtain a +1 points at the same distance A j , A perpendicular line is drawn through the point, which divides the feasible region into an extreme point in the F1 direction, serving as the Pareto front point: (18) (19) Energy storage configuration schemes are obtained through the NNC method. x The sequence of objective functions F1 and F2 is used to minimize the economic cost of social power supply and the social power supply violation event. The bi-objective Pareto front curve is plotted with F1 as the horizontal axis and F2 as the vertical axis.

[0034] S3. Calculate the effect of suppressing power curtailment and power shortage time and the return on investment of the pumped storage power station after configuration based on the dual-objective configuration scheme to obtain the final energy storage configuration scheme.

[0035] (1) The calculation methods for the effect of the pumped storage power station on suppressing power curtailment and power shortage time include: (20) ;(twenty one) In the formula, , To configure the power curtailment before and after the pumped storage power station; , To configure the power shortage before and after the pumped storage power station; , To determine the changes in annual abandoned and shorted electricity before and after configuring pumped storage power stations; , To measure the changes in annual curtailment rate and power shortage rate before and after configuring pumped storage power stations.

[0036] (2) The return on investment of configuring pumped storage power stations.

[0037] By comparing the annual comprehensive operating costs before and after configuring pumped storage, the changes in system operating costs brought about by configuring pumped storage can be calculated. Further, by introducing annual net profit and annual discounted investment cost, the return on investment of the pumped storage power station can be calculated. Only when A value greater than 1 indicates that the investment is economically feasible.

[0038] ;(twenty two) In the formula, , To determine the annual comprehensive operating costs before and after configuring the pumped storage power station; To determine the annual net profit of the pumped storage power station; To determine the return on investment for pumped storage power stations.

[0039] The above calculations demonstrate the significant improvement compared to the original configuration, and the percentage reduction in curtailment and power shortage rates achieved after the configuration. Based on actual needs, the dual-objective Pareto front curve was further simplified to obtain the optimal energy storage configuration for final decision support.

[0040] Example 2: This embodiment uses annual power data from a local power distribution network in Northeast China as the example system. The generating capacities of wind power, photovoltaic power, hydropower, thermal power, and gas-fired power are 2000, 1000, 800, 100, and 1000 million kW, respectively, with a peak load of 18 million kW. The measured historical annual wind power generation, photovoltaic power generation, and load power are as follows: Figure 4 .

[0041] The system does not configure the annual power supply and demand time series simulation results for the pumped storage power station scenario, as follows: Figure 5 As shown, the system requires load demand response for 1383 hours annually to reduce power shortages. During certain periods, due to the ramp-up and start-up / shutdown constraints of thermal and gas-fired power generation, both thermal power output and power curtailment occur simultaneously, increasing the system's curtailment volume. The system's maximum annual curtailment power is 13.38 million kW, with an annual curtailment duration of 2675 hours and an annual curtailment volume of 8.601 billion kWh, resulting in a curtailment rate of 13.34%. The maximum annual power shortage is 6.59 million kW, with an annual shortage duration of 1159 hours and an annual shortage volume of 2.041 billion kWh, resulting in a shortage rate of 1.93%.

[0042] To more clearly reveal the causes of power curtailment / shortage under the system operation scheme, a typical weekly power dispatch scheme with both power curtailment and shortage is illustrated, as follows: Figure 6 As shown in the figure, typical days of power curtailment occur when wind / solar power is at its peak and load is low, with gas-fired power plants shut down all day and thermal power plants operating at minimum technical output for extended periods. Typical days of power shortage occur when load peaks coincide with wind / solar off-peak periods, and even full output from conventional power sources is insufficient to meet demand, necessitating demand response. In extreme cases, orderly load shedding may also be required. The cumulative curtailment volume for a typical week with both curtailment and power shortage was 254.79 million kWh, and the cumulative power shortage was 19.28 million kWh. During this period, the power system showed relatively small differences in the matching between power supply and load demand, with curtailment / power shortage events occurring alternately.

[0043] The above analysis shows that there is an urgent need to introduce energy storage to improve the absorption and peak-shaving capacity of renewable energy; to provide rapid backup during periods of power shortage, thereby enhancing system reliability, resilience and operating efficiency.

[0044] With minimizing the social power supply cost F1 and minimizing the curtailment / deficit power F2 as the dual objectives, three methods—multi-objective particle swarm optimization (MOPSO), multi-objective gray wolf method (MOGWO), and normalized normal constraint method (NNC)—were used to calculate the dual-objective Pareto front of the optimal capacity configuration scheme for pumped-storage power stations. The results are as follows: Figure 7 As shown.

[0045] The MOGWO method, by employing a three-alpha wolf approach to explore, achieves a strong global Pareto front but has weaker boundary search capabilities. The MOPSO method, by focusing on a single optimal individual, enhances boundary search capabilities but is prone to getting trapped in local optima. The NNC-MILP method, through stepwise partitioning of the feasible region and a dual convergent model, yields a more optimal boundary and a more uniform and complete Pareto front, facilitating decisions on optimal capacity configuration schemes for pumped storage power plants.

[0046] If the solution that minimizes the social cost of electricity supply is considered the optimal solution, then the optimal configuration of pumped storage power stations is as follows: Figure 8 As shown, with a pumped storage capacity of approximately 4.25 million kW and reservoir capacity supporting 8 hours of full power generation (equivalent to a capacity configuration of 34 million kWh), the annual comprehensive operating cost of the provincial power system decreased from 47.166 billion yuan to 42.363 billion yuan. If the configured power is further increased, the incremental wind and solar power that can be absorbed is relatively small, and the rising investment and idle maintenance costs will cause the marginal benefits to turn from positive to negative.

[0047] An annual time-series production simulation was performed on the regional power system after configuring pumped storage power stations with optimal capacity, as follows: Figure 9 , Figure 10 , Figure 11 As shown, according to the system's annual time-series production simulation results, the pumped storage power station is in pumped storage mode for 1994 hours a year, consuming 4.352 billion kWh of electricity; it is in power generation mode for 1997 hours a year, generating 3.264 billion kWh of electricity. The annual full-power generation hours are 768 hours, the annual full-power charge-discharge hours are 1793 hours, and the equipment utilization rate is 20.46%.

[0048] The optimal configuration capacity of the pumped storage power station is 34 million kWh. 90% of the configuration capacity (i.e., 30.6 million kWh) is used as the upper limit of the capacity, and 10% of the configuration capacity (i.e., 3.4 million kWh) is used as the lower limit of the capacity. The daily clearing capacity of the pumped storage power station is set at 10.75 million kWh (31.62% SOC). The reason for setting the daily clearing capacity at 31.62% SOC is that the curtailment of electricity is concentrated in the early morning when wind power generation is high and the load is low, and at noon when wind and solar power generation is high and the load is normal. The power shortage is concentrated in the night when solar power generation is zero and wind power generation is low. Therefore, the pumped storage operation generally shows a preference for charging first and then discharging.

[0049] After the pumped storage power stations were properly configured, the system wasted 4.761 billion kWh of electricity and suffered a power shortage of 733 million kWh throughout the year, which was an improvement of 44.65% and 64.09% respectively compared with the system without pumped storage power stations.

[0050] like Figure 12As shown, after configuring pumped storage power stations, the typical weekly curtailment period decreased from 67 hours to 48 hours, and the curtailed amount decreased from 255 million kWh to 177 million kWh; the power shortage period was reduced from 24 hours to zero, and both curtailment and power shortage issues were significantly improved. However, in scenarios of continuous curtailment / power shortage throughout the day, if pumped storage power stations maintain daily clearing constraints, their peak-shaving and valley-filling capabilities will be severely limited.

[0051] The impact and economic feasibility analysis of configuring pumped storage power stations on conventional power sources, and the detailed annual system operation results before and after configuring pumped storage are shown in Table 1 below, which shows the results before and after configuring pumped storage power stations in the planned target year.

[0052] Table 1

[0053] After the installation of pumped storage power stations, during periods of low wind and solar power generation and power shortages, the pumped storage power stations can first absorb thermal power and then discharge it during the power shortage periods. This reduces the magnitude of the net load, causing the annual operating hours of thermal power units to increase from 5176 hours to 5208 hours. Meanwhile, the peak-shaving function of gas-fired power plants is replaced by the cheaper pumped storage, causing the annual operating hours to decrease sharply from 3018 hours to 1498 hours.

[0054] After configuring pumped storage, the system curtailment rate decreased sharply from 13.34% to 7.38%, and the power shortage rate decreased sharply from 1.93% to 0.69%, indicating that the reasonable configuration of pumped storage has a good effect on peak regulation.

[0055] The investment in pumped storage power stations is 1.477 billion yuan per year, which reduces the annual comprehensive cost from 47.166 billion yuan per year without pumped storage power stations to 42.363 billion yuan per year, equivalent to a profit of 4.803 billion yuan per year, with a return on investment of 325%, making the investment economically feasible.

[0056] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for configuring pumped storage power stations in a provincial power system based on the NNC-MILP method, characterized in that, Includes the following steps: S1. Construct a peak-shaving demand model based on the components of the provincial power system. The peak-shaving demand model is used to obtain the peak-shaving demand assessment results for the planned target year. S2. Construct a pumped storage power-capacity configuration model, and based on the pumped storage power-capacity configuration model and the peak-shaving demand model, construct a dual objective function; use the NNC method to solve the dual objective function to obtain the dual objective configuration scheme; S3. Calculate the effect of suppressing power curtailment and power shortage time and the return on investment of the pumped storage power station after configuration based on the dual-objective configuration scheme to obtain the final energy storage configuration scheme.

2. The method for configuring pumped storage power stations in a provincial power system based on the NNC-MILP method according to claim 1, characterized in that, The assessment results of peak-shaving demand in the planned target year include: abandoned power, power shortage, abandoned power, power shortage power, abandoned power duration, power shortage duration, peak value, time-series distribution, and coverage and alternation. The methods for obtaining the abandoned power, the shortage power, the abandoned power, and the shortage power include: ； ； ； In the formula, Indicates the net load of the regional power system; For electrical load; , The power in wind power maximum power point tracking mode and the power in solar power maximum power point tracking mode; , These represent the power curtailment and power shortage of the regional power system, respectively. , These represent the amount of abandoned electricity and the amount of electricity shortage in the regional power system, respectively. Indicates the total number of time periods in the configuration model; , , These represent the installed capacity of pumped storage power stations, thermal power units, and gas turbine units, respectively. , This indicates the curtailment rate and power shortage rate of the regional power system.

3. The method for configuring pumped storage substations in a provincial power system based on the NNC-MILP method according to claim 1, characterized in that, The pumped storage power-capacity configuration model includes: the cost model of the pumped storage power station, the power-capacity coupling constraints of the pumped storage power station, and the daily clearing constraints of the pumped storage power station. The power-capacity coupling constraints of the pumped storage power station include: ； ； in, ； In the formula, , This refers to the rated installed power and rated installed capacity of the pumped storage power station. , They are respectively t The pumped storage power station displays both its power generation and pumping status indicators at all times. Power generation capacity; For real-time power storage; This is the lower limit of the charge capacity of pumped storage power stations; , These are the power generation operating efficiency and the pumping operating efficiency, respectively. This represents the time granularity of the model.

4. The method for configuring pumped storage substations in a provincial power system based on the NNC-MILP method according to claim 1, characterized in that, The dual objective function includes: a function to minimize the social power supply cost and a function to minimize social power supply violation events; The objective function F1 for minimizing the social cost of electricity includes: ； In the formula, The social power supply cost after configuring pumped storage power stations in the planned target year; , Costs of wind power generation and photovoltaic power generation; , , Costs of hydropower generation, thermal power generation, and gas-fired power generation; , Costs related to demand response and load shedding; As a penalty for abandoning electricity; This covers the investment, construction, operation, and maintenance costs of pumped storage power stations; This represents the total investment cost over the entire life cycle of a pumped storage power station. The objective function F2 for minimizing social power supply violation events includes: ； In the formula, This refers to the total annual amount of electricity wasted and the total amount of electricity shortage. This refers to the load shedding power.

5. The method for configuring pumped storage power stations in a provincial power system based on the NNC-MILP method according to claim 1, characterized in that, The methods for calculating the effect of the pumped storage power station on suppressing power curtailment and power shortage time after configuration include: ； ； In the formula, , To configure the power curtailment before and after the pumped storage power station; , To configure the power shortage before and after the pumped storage power station; , To determine the changes in annual abandoned and shorted electricity before and after configuring pumped storage power stations; , To measure the changes in annual curtailment rate and power shortage rate before and after configuring pumped storage power stations.

6. The method for configuring pumped storage power stations in a provincial power system based on the NNC-MILP method according to claim 1, characterized in that, The methods for calculating the return on investment of pumped-storage power stations after configuration include: ； In the formula, , To determine the annual comprehensive operating costs before and after configuring the pumped storage power station; To determine the annual net profit of the pumped storage power station; To determine the return on investment for pumped storage power stations.

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