A method for preventing water from being abandoned by controlling the upper limit of water level of a stepped faucet

Abstract

The present application belongs to the technical field of cascade hydropower optimal scheduling, and proposes a kind of anti-abandoned water cascade leader hydropower water level upper limit forward dynamic control method for renewable energy consumption problem.The method is based on runoff data and power station operation parameters in wet year, sets a prediction period T, to ensure that there is no water abandonment in the control period.Through the construction of extreme scene working condition, the minimum outflow boundary of the leader power station is recursively calculated from bottom to top, combined with the water balance relationship, the initial reservoir capacity is iteratively calculated, and the initial water level is determined by using piecewise linear interpolation method, and the overrun correction is carried out.In the simulation period, the rolling calculation strategy is used to dynamically update the water level upper limit, and the complete water level upper limit dynamic control curve is formed.Compared with the traditional static water level upper limit constraint, the dynamic control method proposed in the present application actively reserves the capacity in flood season to prevent water abandonment, avoids the adjustable reservoir capacity interval for new energy consumption, gradually rises in dry season to ensure power generation, and can effectively improve the regulation capacity of cascade hydropower.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cascade hydropower optimization scheduling, in particular to a kind of cascade leading water level upper limit of water level of preventing water. BACKGROUND

[0002] With the rapid development of renewable energy, the proportion of wind power, photovoltaic and other new energy is rising. At the same time, due to the significant randomness and volatility of new energy generation, new energy consumption has become the main industry problem. Under this background, the water power dispatching system can play its flexible adjustment ability, effectively compensate the intermittency and uncontrollability of wind power and photovoltaic, and provide help for new energy consumption problem. Combined with the advantages of rich and concentrated water resources, the seasonal regulation capacity of the leading reservoir capacity in cascade hydropower station group is deeply excavated, the generation of water abandonment phenomenon in cascade regulation is effectively reduced, and the upper limit of water level of leading hydropower is optimized. How to scientifically determine the water level operation boundary of the leading hydropower station in cascade at the key time node under the background of different time scales has become a prominent technical difficulty in the field of optimization scheduling research. If the upper limit of water level operation is too high, the available reservoir capacity of the reservoir will be compressed, and the new energy consumption space cannot be avoided. Therefore, the control of water level operation upper limit of cascade leading hydropower station is the key technology for water power base to improve the regulation capacity of new energy consumption, and how to consider the coupling characteristics of water power correlation of cascade hydropower station and scientifically define the water level operation upper limit of cascade leading hydropower station to minimize the risk of water abandonment is the key problem to be solved at present.

[0003] From the current cascade hydropower optimization scheduling model:

[0004] The setting of upper limit boundary constraint condition of water level operation in dry season and wet season in the current optimization scheduling model is mostly static fixed value, which lacks dynamic change of time scale and has certain limitation. For example, the document: Jiang Jia-yi, Xu Bin, Yue Hao, etc. Cascade reservoir group wind light water multi-energy complementary multi-objective optimization scheduling model [J / OL]. China rural water conservancy and hydropower, 1-18 [2025-06-17]. Http: / / kns.cnki.net / kcms / detail / 42.1419.tv.20250110.1529.004.html. The multi-objective optimization scheduling model of cascade reservoir group wind light water multi-energy complementary proposed in the document, although the multi-objective relationship is coordinated through non-inferior solution set analysis, and the model effect is verified by taking Yuan water basin as an example, but due to the single setting of water level upper limit boundary constraint, it is difficult to adapt to large-scale wind light complementary system, and the support for improving new energy consumption capacity is limited, especially it is difficult to meet the demand of improving water power base consumption capacity under the guarantee of water abandonment risk.

[0005] As the literature: Chen Wen, Sun Bo, Zhang Bo, etc. Multi-objective scheduling method of cascade hydropower station based on improved NSGA-II algorithm [J]. Water and energy science, 2024, 42 (08): 182-186+154. DOI: 10.20040 / j.cnki.1000-7709.2024.20240306., Although the introduction of Pareto frontier and improved NSGA-II algorithm improves the multi-objective scheduling optimization ability, effectively coordinates the flood control and power generation goals, but there are still deficiencies in the operation upper limit control: the water level constraint is a fixed value, without considering the change of hydrological and meteorological conditions, lacking the flexibility of the leading reservoir operation, difficult to adapt to the regulation and control demand in different dry and wet periods. In addition, its water level upper limit is still based on the traditional flood control water level setting, without dynamic adjustment combined with new energy fluctuation load, lacking of "reserved storage capacity" to enhance the mechanism of renewable energy consumption. Overall, this method is difficult to meet the needs of reducing the risk of water abandonment and improving the ability of new energy consumption of the patent. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a method for preventing water abandonment in cascade leading hydropower water level operation upper limit forward dynamic control, which realizes the forward dynamic control of the operation upper limit of the cascade hydropower water level for the purpose of preventing water abandonment by establishing a reverse iteration calculation, combined with the hydraulic coupling relationship, flow constraint, reservoir capacity and water level boundary of the cascade hydropower station, and the dynamic water level operation upper limit is calculated, so as to effectively reduce the risk of water abandonment in cascade hydropower station, improve the comprehensive utilization rate of water resources, and improve the new energy consumption capacity of the water and electricity base station. And take the Xiaowan-Manwan cascade hydropower station in Lancang River Basin as the engineering background for application test, the results show that the invention can effectively realize the forward dynamic control of the operation upper limit of the cascade hydropower water level for the purpose of preventing water abandonment.

[0007] The technical scheme of the present application is as follows:

[0008] A method for preventing water abandonment in cascade leading hydropower water level operation upper limit forward dynamic control, the steps are as follows:

[0009] Step (1): initial data preparation.

[0010] Runoff data: according to the long series of historical runoff data, the hydrological fitting is carried out, and the runoff information is used to the maximum extent. According to the fitted Pearson III type curve and the selected guarantee rate, the design annual runoff is calculated, and the typical observation year closest to the design annual runoff corresponding to different design guarantee rates is found out as the typical representative year, and the runoff data of the 10% hydrological guarantee rate corresponding to the abundant year is selected as the input.

[0011] Basic parameters of power station: including normal high water level, flood control water level, dead water level, upper and lower limits of outflow and power generation flow, upper and lower limits of reservoir capacity, adjustable reservoir capacity value, etc.

[0012] Step (2): Setting the forecast period T.

[0013] A non-water-waste prediction period T is established as the forward-looking dynamic control cycle for the upper limit of water levels in cascade hydropower projects. Its core objective is to ensure that no water waste occurs within T days. In each round of control, using the initial date as a baseline, a reverse iterative calculation method is used to calculate the upper limit of water levels on the initial date by iterating daily from the end of the prediction period until the initial date is reached. This value is the forward-looking dynamic control value for the upper limit of water levels at the main hydropower station to avoid water waste within the prediction period T.

[0014] Step (3): Reverse iterative calculation.

[0015] a. Extreme Scenario Construction: Under the premise that each hydropower station in the cascade meets the constraints such as upper and lower limits of water level and minimum outflow, it is assumed that the downstream power station in the cascade will not abandon water during the forecast period and will maintain normal high water level operation with minimum outflow. It is also assumed that at the end of the forecast period, the reservoir water level of the leading hydropower station in the cascade will be at the normal high water level.

[0016] b. Calculation of Minimum Outflow Boundary Constraint: Utilizing the hydraulic connection between the upstream and downstream cascade hydropower stations, the difference between the minimum daily outflow demand of the downstream regulating hydropower station and the interval flow for the corresponding period of a selected representative year is calculated. This result is then compared with the minimum outflow of the upstream power station, and the maximum value is taken. This is calculated level by level and used as the boundary constraint for the minimum outflow of the upstream controlling hydropower station. The mathematical expression is as follows:

[0017]

[0018]

[0019] In the formula, For hydroelectric power station No. Inbound flow at the end of the period, in m³ 3 / s; For hydroelectric power station exist Natural runoff volume during a given period, in cubic meters (m³). 3 / s; For hydroelectric power station No. Power generation flow at the end of the period, in m³ 3 / s; For hydroelectric power station No. The water discharge at the end of the time period, in meters. 3 / s; For hydroelectric power station No. Outbound flow at the end of the period, in m³3 / s.

[0020]

[0021] wherein, is the water power station is the water power station the outflow of the water power station in the time period, in units of m 3 / s; is the water power station is the water power station the maximum outflow value of the water power station in the time period, in units of m 3 / s; is the water power station is the water power station the minimum outflow value of the water power station in the time period, in units of m 3 / s.

[0022]

[0023] wherein, is the water power station is the water power station the minimum outflow of the most downstream daily regulation water power station, in units of m 3 / s; the result of is compared with the minimum outflow value of the upstream water power station the greater value is taken as the minimum outflow of the upstream water power station. Along the cascade topology, from bottom to top, recursively, the is taken as the lower limit of the outflow of the upstream water power station, and iterative calculation is performed until the minimum outflow boundary constraint of the headwater power station of the cascade is determined.

[0024] c. Calculate the initial reservoir capacity: using the water balance relationship, the initial reservoir capacity of the prediction period T time control cycle is obtained by iterative inverse calculation day by day at the end of the set prediction period T time control cycle. The mathematical expression is as follows:

[0025]

[0026] wherein, is the water power station is the water power station the reservoir capacity of the water power station at the end of the time period, in units of ten thousand m 3 ; is the water power station is the water power station the reservoir capacity of the water power station at the end of the time period, in units of ten thousand m 3 ; is the water power station is the water power station the inflow of the water power station at the end of the time period, in units of m 3 / s; is the water power station is the water power station Generation flow at the end of the period, unit: m 3 / s; is the water power station The Abandoned water flow at the end of the period, unit: m 3 / s; is the period time, unit: s.

[0027] d. Calculate the initial water level, using the piecewise linear interpolation method to linearize the water level-storage capacity characteristic curve of the water power station. The linearization mathematical expression is as follows:

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034] In the formula, and are the water power station The lower limit and upper limit of the reservoir historical operation data, unit: ten thousand m 3 , the water power station The reservoir storage capacity range is discretized into intervals, is the interval index; is the water power station The water level corresponding to the storage capacity of the interpolation node, unit: m; is the water level-storage capacity curve function of the water power station ; is a 0-1 type indicator variable, is the constraint condition that satisfies, that is, to ensure that the water power station The storage capacity of the reservoir is located in the unique interpolation interval; is the actual storage capacity value of the water power station in the interpolation interval, corresponding to the time , unit: ten thousand m 3 ; is the reservoir storage capacity of the water power station The interpolation node, unit: ten thousand m 3 ; is the actual storage capacity value of the water power station in the Reservoir capacity at the end of the period, unit: ten thousand m 3 The relationship between the water level of the reservoir at any time and the reservoir capacity can be converted into .

[0035] e. Initial water level correction: the obtained initial water level result needs to meet the water level limit constraint, if the initial water level is higher than the normal high water level, it is corrected to the normal high water level, at this time it is indicated that even if the cascade leader hydropower station is operated at the normal high water level, the cascade will not produce water abandonment in the control period; if the initial water level is lower than the dead water level, it is corrected to the dead water level, at this time it is indicated that even if the main reservoir is adjusted from the dead water level, the cascade will still produce water abandonment in the control period. The mathematical expression is as follows:

[0036]

[0037] In the formula, the water level of the hydropower station The water level of the hydropower station at the end of the period, unit: m, the normal high water level of the hydropower station , unit: m, the dead water level of the hydropower station , unit: m.

[0038] f. Dynamic result output: the simulation period N is the total time range for building a complete forward-looking dynamic water level upper limit control curve, covering multiple prediction periods T, reflecting the continuous dynamic control process under the background of long-term scheduling. In the simulation period, a rolling calculation control strategy is adopted: every day (the time step is one day), the prediction period T window is moved one day forward, and the reverse iteration calculation is re-executed. That is, every time a new initial date is taken as the starting point, a control interval with a length of T is extended forward, a new prediction period T water level upper limit calculation window is built. The water level upper limit control results obtained by each rolling calculation are summarized and connected in time sequence, which can form a cascade leader hydropower water level upper limit dynamic control curve covering the entire simulation period N. According to the actual scheduling demand, different lengths of prediction period T (such as 7 days, 10 days, 15 days, 30 days) can be set, and the optimization results under different prediction periods can be compared and analyzed to evaluate the adaptability and regulation effect of the method.

[0039] The invention has the following beneficial effects: during the flood season, the water level operation upper limit control result of the hydropower station is obviously lower than the flood limit water level, which can balance the flood control constraint and power generation demand of the reservoir under the goal of preventing water abandonment. After entering the dry season, with the gradual reduction of inflow, the water level operation upper limit also begins to gradually rise to near the normal high water level, so as to ensure its water storage and power generation benefit. The invention provides an effective technical means for the water level operation upper limit control of the cascade leader hydropower station to prevent water abandonment. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a schematic diagram of a T=7-day simulation result;

[0041] Figure 2 is a comparison schematic diagram of multi-look-ahead simulation results;

[0042] Figure 3 is a general solution framework diagram of the method of the present application. DETAILED DESCRIPTION

[0043] The present application will be further described below in conjunction with the accompanying drawings and implementation cases.

[0044] The general flow of the present application is shown in Figure 3 .

[0045] This implementation case takes the Xiaowan-Manwan cascade hydropower station located in the Lancang River basin in Yunnan Province as an implementation case to test the present application, and the specific steps are as follows:

[0046] Step (1): initial data preparation.

[0047] Historical runoff data: 60 years of natural historical runoff data from 1965 to 2024 in the Lancang River basin were collected, and after statistical analysis, a Pearson-III type distribution curve was fitted, a 10% hydrological guarantee rate was set, representative year data was derived, and the typical representative year data of the wet year 2012 was selected as the input data for simulation and calculation.

[0048] Hydropower station basic data: The installed capacity data of the cascade hydropower station, the upper and lower limit data of the reservoir capacity, the upper and lower limit data of the water level, the upper and lower limit data of the discharge and power generation flow, the flood control water level data, the initial and final reservoir capacity, and the water level-reservoir capacity characteristic curve were collected from the basin control center.

[0049] Step (2): look-ahead period T setting.

[0050] The look-ahead period T=7 days is set as the upper limit of the cascade hydropower water level forward-looking dynamic control period, and the core goal is to ensure that there is no water abandonment within 7 days. Taking May 20, 2012 as the initial date, through the reverse iteration calculation method, starting from the look-ahead period end date May 26, the daily reverse iteration back calculation is performed until the initial date May 20, so as to calculate the water level upper limit control value of Xiaowan hydropower station on the initial date. This value is the water level upper limit control target of Xiaowan hydropower station to avoid water abandonment within the look-ahead period T.

[0051] Step (3): reverse iteration calculation.

[0052] a. Extreme scenario construction: Under the premise that each hydropower station in the cascade meets the upper and lower limits of water level and the minimum outflow, it is assumed that the downstream power station in the cascade will not abandon water during the forecast period and will maintain normal high water level operation with the minimum outflow. It is also assumed that at the end of the forecast period, the water level of the reservoir of the leading hydropower station in the cascade is at the normal high water level.

[0053] b. Minimum outflow boundary constraint calculation: Utilizing the hydraulic connection between upstream and downstream cascade hydropower stations, the difference between the minimum daily outflow demand of the downstream regulating hydropower station and the interval flow for the corresponding period of a selected representative year is calculated. This result is then compared with the minimum outflow of the upstream power station, and the maximum value is taken. This value is then converted level by level and used as the minimum outflow boundary constraint for the upstream controlling hydropower station. The mathematical expression is as follows:

[0054]

[0055]

[0056] In the formula, For hydroelectric power station No. Inbound flow at the end of the period, in m³ 3 / s; For hydroelectric power station exist Natural inflow runoff at the end of the period, in m³ 3 / s; For hydroelectric power station No. Power generation flow at the end of the period, in m³ 3 / s; For hydroelectric power station No. The water discharge at the end of the time period, in m 3 / s; For hydroelectric power station No. Outbound flow at the end of the period, in m³ 3 / s.

[0057]

[0058] In the formula, For hydroelectric power station No. Outbound flow rate for a given period, in m³. 3 / s; For hydroelectric power station No. The maximum outbound flow rate for a given period, in m³. 3 / s; For power station exist Minimum outflow rate for a given period, in m³.3 / s.

[0059]

[0060] In the formula, For hydroelectric power station The minimum outflow from the downstream regulating hydropower station, in m³ / s. 3 / s; To represent the interval flow for the corresponding period of the year, The results are related to the minimum outflow value of the upstream hydropower station. For comparison, the larger value is taken as the minimum outflow of the next-level hydropower station. Following the cascade topology recursively from bottom to top, ... As the lower limit of the outflow from the upstream hydropower station, iterative calculations are performed until the minimum outflow boundary constraint of the leading hydropower station in the cascade is determined.

[0061] c. Calculate the initial reservoir capacity. Using the water balance formula, set the upper limit of the water level on May 26, 2012 (the end date of the forecast period for Xiaowan Hydropower Station) as the normal high water level. Iterate backwards day by day to obtain the initial reservoir capacity on May 20, 2012 (the beginning date of the forecast period). The mathematical expression is as follows:

[0062]

[0063] In the formula, For hydroelectric power station No. The reservoir capacity at the end of the period is expressed in 10,000 m³. 3 ; For hydroelectric power station No. The reservoir capacity at the end of the period is expressed in 10,000 m³. 3 ; For hydroelectric power station No. Inbound flow at the end of the period, in m³ 3 / s; For hydroelectric power station No. Power generation flow at the end of the period, in m³ 3 / s; For hydroelectric power station No. The water discharge at the end of the time period, in meters. 3 / s; The time period is expressed in seconds (s).

[0064] d. The initial water level is calculated using the piecewise linear interpolation method described in the literature Zhang Y, Cheng C, Cao R, et al. Multivariate probabilistic forecasting and its performance's impacts on long-term dispatch of hydro-wind hybrid systems[J]. Applied Energy, 2021, 283: 116243. This method linearizes the water level-reservoir capacity characteristic curve of the hydropower station. By dividing the nonlinear functional relationship between water level and reservoir capacity into several linear intervals (piecewise linear), a simple linear expression is used to accelerate the solution process. This ensures the accuracy of the relationship between water level and reservoir capacity and the efficiency of the calculation; that is, the corresponding water level can be obtained simply by inputting the reservoir capacity. The linearized mathematical expression is as follows:

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071] In the formula, and Hydropower stations Lower and upper limits of historical reservoir operation data, in units of 10,000 m³ 3 Hydropower station The reservoir capacity range is discretized into Each interval For range index; For hydroelectric power station No. The water level corresponding to the reservoir capacity of each interpolation node, in meters; For hydroelectric power station Water level-reservoir capacity curve function; It is a 0-1 type indicator variable. The constraints it satisfies, namely, ensuring the hydropower station The reservoir's capacity lies within a unique interpolation interval; For hydroelectric power station In the Interpolation interval, corresponding time The actual storage capacity, in ten thousand cubic meters.3 ; Reservoir storage capacity Reservoir storage capacity Reservoir storage capacity 3 ; Reservoir storage capacity Reservoir storage capacity Reservoir storage capacity 3 . The relationship between reservoir water level and storage capacity at any time can be converted to .

[0072] e. Initial water level correction, the resulting initial water level result should meet the water level limit constraint, if the initial water level is higher than the normal high water level, it will be corrected to the normal high water level, at this time it shows that even if the main reservoir is operated at the normal high water level, the cascade will not produce waste water; if the initial water level is lower than the dead water level, it will be corrected to the dead water level, at this time it shows that even if the main reservoir is operated from the dead water level, the cascade will still produce waste water. Mathematically expressed as follows:

[0073]

[0074] In the formula, Reservoir water level Reservoir water level Reservoir water level Normal high water level Normal high water level Dead water level Dead water level

[0075] f. Dynamic result output, using rolling calculation strategy to advance the prediction period T window: the initial date is advanced day by day (the time step is one day), and the prediction period T window is translated forward, and the reverse iteration calculation is re-executed. Each time a new initial date is used as the starting point to build a new prediction period T calculation window. The initial date water level upper limit control value obtained by all rolling calculations is connected in time sequence to form the dynamic control curve of the cascade leading water level upper limit. In the implementation process of the method, May 20, 2012 to June 20, 2012 is taken as the simulation period N, a total of N=31 days, the prediction period T=7 days, then the dynamic water level upper limit control result is obtained by continuously rolling calculation N−T+1=25 times in the 31-day simulation period, as shown in Figure 1 and Table 1. Further set different lengths of the prediction period (such as 10 days, 15 days, 30 days), and carry out simulation and comparative analysis on the water level upper limit dynamic control result under each prediction period, to evaluate the adaptability and scheduling effect of the method under different scheduling periods, the results are as follows: Figure 2The results show that the change of the prediction period has a significant impact on the control strategy, and the derived dynamic water level operation upper limit value shows a gradual downward trend as the prediction period T increases, especially before the flood season or in the high water period.

[0076] Table 1 Prediction period T = 7 abandoned water level upper limit control results

[0077]

Claims

1. A water-abandoning step tap water level upper limit forward dynamic control method, characterized in that, The steps are as follows: Step (1): initial data preparation; Including runoff data and basic parameters of power stations; Step (2): prediction period T setting; Determine the non-waste prediction period T as the upper limit of the water level of the cascade hydropower station, and the target is to ensure that there is no waste within T days; In each round of control, take the initial date as the benchmark, and start from the date at the end of the prediction period, calculate day by day in reverse, and back to the initial date, so as to calculate the upper limit control value of the initial date, which is the upper limit of the water level of the leading hydropower station in the prediction period T to avoid waste; Step (3): reverse iterative calculation; a. Extreme scenario construction: under the premise that each hydropower station in the cascade meets the upper and lower limits of the water level and the minimum discharge flow constraint, it is assumed that the downstream power station in the cascade does not waste water in the prediction period, and maintains normal high water level with the minimum discharge flow; At the same time, it is assumed that at the end of the prediction period, the water level of the leading hydropower station in the cascade is at the normal high water level; b. Minimum discharge flow boundary constraint calculation: use the hydraulic connection between the upstream and downstream of the cascade to calculate the difference between the minimum discharge flow requirement of the downstream daily regulation hydropower station and the interval flow of the selected representative year in the corresponding period, and compare it with the minimum discharge flow of the upstream power station to take the maximum value; Gradually fold to obtain the minimum discharge flow boundary constraint of the upstream control hydropower station; Mathematical expression is as follows: c. Calculate the initial storage capacity: use the water balance relationship to iteratively calculate the initial storage capacity of the prediction period T time control period; Mathematical expression is as follows: wherein is the water power station is the storage inflow at the end of the period, in m 3 / s; is the water power station is the natural runoff flow in the period, in m 3 / s; is the water power station is the power generation flow at the end of the period, in m 3 / s; is the water power station is the water abandonment flow at the end of the period, in m 3 / s; is the water power station is the storage outflow at the end of the period, in m 3 / s; wherein is the water power station the outflow of the water power station in the time interval, in m 3 / s; is the water power station the maximum outflow value of the water power station in the time interval, in m 3 / s; is the water power station in the minimum outflow value of the water power station in the time interval, in m 3 / s; In the formula, The water power station The minimum discharge of the downstream daily regulation water power station, unit: m 3 / s; will The results are compared with the minimum discharge value of the upstream water power station Take the larger value as the minimum discharge of the upper level water power station; Recursion along the cascade topology from bottom to top, the As the lower limit of the discharge of the upstream hydropower station, the iterative calculation is carried out until the minimum discharge boundary constraint of the cascade leader hydropower station is determined. d. Calculate the initial water level, and use the piecewise linear interpolation method to realize the linearization processing of the water level-storage capacity characteristic curve of the hydropower station; Linearization mathematical expression is as follows: wherein is the water power station is the reservoir storage at the end of the period, in units of 10 3 ; is the water power station is the reservoir storage at the end of the period, in units of 10 3 ; is the water power station is the inflow at the end of the period, in units of m 3 / s; is the water power station is the generation at the end of the period, in units of m 3 / s; is the water power station is the spillage at the end of the period, in units of m 3 / s, is the period time, in units of s; e. Initial water level correction: the obtained initial water level result should meet the water level limit constraint, if the initial water level is higher than the normal high water level, it will be corrected to the normal high water level, at this time it shows that even if the leading hydropower station in the cascade runs at the normal high water level, the cascade will not produce waste; If the initial water level is lower than the dead water level, it will be corrected to the dead water level, at this time it shows that even if the main reservoir is adjusted from the dead water level, the cascade will still produce waste; Mathematical expression is as follows: In the formula, and are the lower limit and upper limit of the historical operation data of the reservoir, respectively, in units of ten thousand m ; 3 , the water level of the hydropower station at the end of the time period ; is the reservoir storage range of the hydropower station ; ; is the water level corresponding to the reservoir storage of the i-th interpolation node, in units of m ; is the water level-storage curve function of the hydropower station ; is a 0-1 type indicator variable , and the constraint condition satisfied thereby is to ensure that the reservoir storage of the hydropower station is located within the unique interpolation interval ; is the actual reservoir storage value of the hydropower station at the corresponding time within the i-th interpolation interval, in units of ten thousand m 3 ; ; is the reservoir storage of the hydropower station at the i-th interpolation node, in units of ten thousand m 3 ; ; is the reservoir storage of the hydropower station at the end of the time period, in units of ten thousand m 3 ; The relationship between the reservoir water level and the reservoir capacity at any time can be converted into ; f. Dynamic result output: simulation period N is the total time range of building complete forward dynamic water level upper limit control curve, covering multiple prediction periods T, reflecting the continuous dynamic control process under the background of long-term regulation; In the simulation period, the rolling calculation control strategy is adopted: every day, move the prediction period T window forward by one day, and re-execute the reverse iterative calculation; That is, every time take the new initial date as the starting point, extend one control interval with a length of T forward, and build a new prediction period T water level upper limit calculation window; wherein is the water power station the water level of the time period, in m, is the water power station normal high water level, in m, is the water power station dead water level, in m; Sum up the water level upper limit control results obtained by each rolling calculation, and connect them in time sequence, which can form the water level upper limit dynamic control curve of the leading hydropower station in the cascade covering the whole simulation period N. ​ 2. The method according to claim 1, wherein, In step (1), runoff data: according to long series of historical runoff data, hydrological curve fitting is carried out to maximize the use of water information; according to the fitted Pearson III type curve and the selected guarantee rate, the design annual runoff is calculated, and the typical observation year closest to the design annual runoff corresponding to different design guarantee rates in the measured data is selected as the typical representative year, and the runoff data of the 10% hydrological guarantee rate corresponding to the abundant year is selected as the input; basic parameters of the power station: including normal high water level, flood control water level, dead water level, upper and lower limits of outflow and power generation flow, upper and lower limits of reservoir capacity, and adjustable reservoir capacity value.

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