Flood regulation control method for pumped storage power station for water exchange between lower reservoir sand blocking reservoir and special reservoir
By constructing an engineering parameter database and using nested iterative calculations, the problem of flood control calculations for water exchange between the sediment-trapping reservoir and the dedicated reservoir was solved, improving the accuracy and safety of flood control design for the lower reservoir of the pumped storage power station.
Patent Information
- Application Number
- CN202511742166.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-02-27
AI Technical Summary
Existing flood control calculation methods are unable to handle the dynamic water exchange between sediment-trapping reservoirs and dedicated reservoirs, as well as multiple uncertainties, which increases the difficulty of flood control design for the lower reservoir of pumped storage power stations.
An engineering parameter database is constructed, a state space set is generated through discretization, nested iterative calculations are performed, the water balance between the two reservoirs is dynamically calculated, the exchange flow driven by the water level difference is analyzed, and finally the flood control high water level of the sediment-trapping reservoir and the special reservoir is determined.
This improves the accuracy of flood control calculations and the safety of engineering projects, providing a reliable basis for the flood control design of the lower reservoir of pumped storage power stations equipped with silt-trapping dams.
Smart Images
Figure CN121580896A_ABST
Abstract
Description
Technical Field
[0001] This invention discloses a flood control method for pumped storage power stations that involves water exchange between the lower reservoir's sediment trap and a dedicated reservoir, belonging to the field of water conservancy engineering and pumped storage power station flood control design technology. Background Technology
[0002] A series of new energy sources, represented by wind power and photovoltaics, are developing rapidly, with their installed capacity continuously expanding. However, due to the randomness and poor regulation capabilities of new energy power generation, their large-scale development requires the construction of flexible regulating power sources and energy storage facilities to avoid the adverse effects of the randomness and volatility of new energy power generation on the power grid. Pumped storage power stations, due to their advantages such as flexible operation, mature technology, economic and environmental benefits, and the ability to provide rotational inertia to the power system, are currently the most suitable flexible regulating power source for large-scale development, especially when combined with wind and solar power generation.
[0003] Some pumped-storage power stations are located in areas with severe soil erosion. During operation, these stations face problems such as siltation encroaching on the effective reservoir capacity and severe wear and tear on the generating units, affecting the project's effectiveness. To mitigate the impact of siltation, pumped-storage power stations typically use a closed reservoir basin method to reduce the amount of silt entering the upper reservoir, while the lower reservoir usually employs methods such as constructing a silt-retaining dam upstream of the main dam and setting up flood discharge and silt-removal tunnels upstream of the dam to further reduce siltation.
[0004] To meet the reservoir's capacity regulation requirements, the distance between the silt-trapping dam and the river-blocking dam is typically quite long, resulting in a relatively long spillway and sediment discharge tunnel upstream of the silt-trapping dam. In some pumped-storage power station designs, to reduce tunnel size and investment while ensuring engineering safety, the design standards for the spillway and sediment discharge tunnel are sometimes lower than those for the water-blocking structures. Simultaneously, to ensure the safety of the silt-trapping dam, spillways and other water-discharging structures are included. This design creates a hydraulic connection between the dedicated reservoir and the silt-trapping reservoir, leading to water exchange between the two reservoirs at high water levels. Furthermore, the pumping and power generation processes of pumped-storage power stations are primarily controlled by the power grid, introducing uncertainty. Therefore, when designing the flood control of the lower reservoir of a pumped storage power station with a silt-trapping dam, it is necessary to consider both the impact of power generation in the upper reservoir on flood regulation in the lower reservoir and the impact of water exchange between the silt-trapping dam and the dedicated reservoir. The superposition of multiple factors makes the calculation of flood regulation of the lower reservoir of a pumped storage power station with a silt-trapping dam significantly more difficult than that without a silt-trapping dam, and the flood control design of the lower reservoir has become one of the challenges faced in engineering design.
[0005] Existing mature flood control calculation methods for pumped storage power stations are mostly limited to single downstream reservoirs and are not applicable to pumped storage power stations where there is water exchange between the downstream sediment trap and the dedicated storage tank. For pumped storage power stations with sediment traps and water exchange between the sediment trap and the dedicated storage tank, flood control calculations for the downstream reservoir must be performed for two reservoirs: one is the sediment trap formed upstream of the sediment trap, and the other is the dedicated storage tank formed between the river dam and the sediment trap. Flood control calculations for the sediment trap need to consider factors such as the natural inflow flood process, the scheduling rules of the flood discharge and sediment removal tunnels, and the water exchange with the dedicated storage tank. Flood control calculations for the dedicated storage tank need to consider factors such as the downstream discharge from the upstream reservoir and the water exchange with the sediment trap. Furthermore, since the timing of the encounter between the natural flood and the downstream discharge from the upstream reservoir, as well as the circulating water volume in the dedicated storage tank, are random, from the perspective of ensuring project safety, it is necessary to find the most unfavorable encounter scenario and determine the design flood level and check flood level of the sediment trap and the river dam. Summary of the Invention
[0006] The main purpose of this application is to provide a solution to the problems in the prior art.
[0007] To achieve the above objectives, this application provides the following technical solution: According to a first aspect of the present invention, the present invention claims protection for a flood control method for a pumped-storage power station involving water exchange between a lower reservoir and a dedicated reservoir, the method comprising: S1. Construct an engineering parameter database to structurally store the physical and hydraulic characteristic parameters of the pumped storage power station. The physical and hydraulic characteristic parameters include at least the natural flood hydrograph at the dam site, the storage capacity curve of the silt-trapping reservoir, the storage capacity curve of the dedicated reservoir, the discharge curve of the dam's spillway structure, the normal water level and the dead water level, and the rated power generation flow. S2, based on the parameters stored in the engineering parameter database, by discretizing and combining multiple uncertain factors affecting the flood control results, a state space set consisting of multiple independent calculation conditions covering all potential unfavorable combinations is constructed. S3, for each calculation condition in the state space set, nested iterative calculations are performed within the main time loop that advances over a preset time period to dynamically calculate the water balance between the sediment-trapping reservoir and the special reservoir throughout the flood process, analyze the dynamic water exchange between the two reservoirs through the spillway at the top of the sediment-trapping dam that is driven by the water level difference between the two, and output the highest water level of the sediment-trapping reservoir and the special reservoir during the entire flood process under each calculation condition; S4. Receive and store the highest water level under all calculation conditions, and after all calculation conditions are completed, determine the flood control high water level of the sediment-trapping reservoir and the flood control high water level of the special reservoir by performing a global maximum value search on all stored highest water levels of sediment-trapping reservoirs and the highest water levels of special reservoirs respectively.
[0008] Furthermore, the state space set constructed by S2 is spanned by at least three mutually orthogonal dimensions, namely: the initial water level of the dedicated reservoir, the start time of the power generation process of the upper reservoir, and the duration of the power generation process of the upper reservoir. The process of generating the state space set includes the following steps: Based on the dead water level and normal water level of the dedicated reservoir, and according to the preset water level spatial step size, the initial water level of the dedicated reservoir is discretized to generate an initial water level vector. Based on the total beneficial regulation capacity of the upper reservoir and the rated power generation flow of the generating units, the maximum continuous power generation duration is calculated. Combined with the total duration of the natural flood process line and the calculation period, by changing the starting position and sequence length of the continuous power generation sequence, a set of power generation flag matrices representing all possible power generation scheduling schemes is generated. Each of the power generation flag matrices is a one-dimensional binary vector, and its element values represent the start-up and shutdown status of the generating units in the corresponding period. The initial water level vector is combined with the set of power generation indicator matrices by performing a Cartesian product to generate the complete state space set.
[0009] Furthermore, the nested iterative calculations performed by S3 in each time period include an outer loop and an inner loop; The outer circulation is used to solve the exchange flow of the spillway of the silt-trapping dam at the end of the time period. The inner circulation is nested within the outer circulation and is used to solve the water level of the silt-trapping reservoir and the water level of the special reservoir at the end of the time period, respectively, given the exchange flow assumed by the outer circulation. The external circulation uses the spillway exchange flow rate at the end of the time period as the iteration variable, while the internal circulation uses the water level of the sediment trap and the water level of the special reservoir at the end of the time period as the iteration variables, respectively. Furthermore, when determining the actual discharge flow of the dam within a preset time period, S3 applies at least one of the following constraints: Downstream flood control safety constraints stipulate that the total downstream discharge through dam structures must not exceed the upstream natural flood discharge at any given time; or The power station's operational safety constraints are implemented by adjusting the outflow from the dam to ensure that the water level in the dedicated reservoir is never lower than the reservoir capacity corresponding to its dead water level at any time.
[0010] Furthermore, the method also includes: When the natural flood hydrograph input during the construction of the engineering parameter database is the design standard flood hydrograph, the flood control high water level finally determined by the method is the design flood level of the silt-blocking dam and the river-blocking dam. When the natural flood process line input during the construction of the engineering parameter database is the verification standard flood process, the flood regulation high water level finally determined by the method is the verification flood level of the silt-blocking dam and the river-blocking dam. When calculating the aforementioned check flood level, an additional safety control logic check is performed before the start of the calculation for each time period: Check the water level of the dedicated reservoir at the end of the previous period. If the water level has exceeded the calculated design flood level of the dedicated reservoir, then forcibly set the power generation flag matrix elements of the current and all subsequent periods to zero to simulate an emergency shutdown of the unit.
[0011] Furthermore, in step S1, the discharge capacity of the spillway connecting the sediment-trapping reservoir and the dedicated reservoir is a function of the head, which is jointly determined by engineering parameters such as the water level of the sediment-trapping reservoir, the water level of the dedicated reservoir, and the elevation of the weir crest or bottom plate of the spillway. When the spillway is a spillway, the head and discharge capacity are calculated as follows:
[0012] In the formula, The water head represents the flow rate; a positive value indicates that water flows from the sediment-trapping reservoir into the dedicated reservoir, while a negative value indicates that water flows from the dedicated reservoir into the sediment-trapping reservoir. For the water level of the silt-trapping reservoir, For the dedicated reservoir water level, The elevation of the spillway crest of the sand-blocking dam. To improve the spillway discharge capacity of the sand-blocking dam, This relates to the relationship between the spillway discharge capacity of the sand-blocking dam and the water head above the weir.
[0013] Furthermore, the power generation indicator matrix is a column vector with n terms, where a value of 1 represents power generation during a period and a value of 0 represents no power generation during a period. For unfavorable considerations, the value 1 should appear consecutively. The matrix must meet the following requirements:
[0014]
[0015] In the formula, d i This is the generator generation status identifier for time period i. This refers to the hydroelectric flow rate of the upper reservoir. W sfd The amount of water available for power generation in the upper reservoir. Q FD Rated power generation flow rate, For calculating the time period, v 2 ( Z n (This refers to the reservoir's normal water level and corresponding capacity.) v 2 ( Z 2,0(This refers to the water level of the dedicated reservoir at the initial calculation time.) Z 2,0 The corresponding storage capacity.
[0016] Furthermore, in step S3, the formula for calculating the power generation reference flow rate for the preset time period is: ; Q fdi This is the sum of the power generation flow from the previous period; In step S3, the amount of water required for pumped-storage power generation that the dedicated reservoir needs to retain needs to be considered, i.e., the minimum water volume in the dedicated reservoir at the end of the time period. The calculation formula is as follows:
[0017] Furthermore, in step S3, to avoid causing man-made flooding downstream, the flow rate discharged to the downstream of the dam must not exceed the natural flood flow rate before the preset time period, i.e., the maximum discharge flow rate of the spillway structure at the end of the time period. The calculation formula is as follows: .
[0018] In the formula, For natural flow processes, Q psi,末 This refers to the discharge capacity of the flood discharge and sediment flushing tunnel at the end of the period. Q xs2i,末0 This refers to the discharge capacity of the dam's spillway structure corresponding to the water level of the dedicated reservoir at the end of the time period.
[0019] Furthermore, in step S3, the formula for calculating the discharge flow at the end of the time period of the dam's spillway structure is as follows:
[0020] In the formula, The average discharge capacity of the spillway of the sand-blocking dam during different time periods. The initial water volume in the dedicated reservoir for that period. The initial discharge capacity of the dam's spillway structures during a given period.
[0021] This application discloses a flood control method for pumped-storage power stations involving water exchange between a lower reservoir and a dedicated reservoir. Belonging to the field of water conservancy engineering and pumped-storage power station flood control design technology, it aims to solve the problem that existing flood control calculation techniques struggle to handle dynamic water exchange and multiple uncertainties between the lower reservoir and the dedicated reservoir. The method involves constructing an engineering parameter database to structurally store the power station's physical and hydraulic characteristics; generating a state space set covering all potentially unfavorable combinations based on discretization principles; performing nested iterative calculations for each operating condition to dynamically calculate the water balance between the two reservoirs and the exchange flow driven by the water level difference; and finally determining the flood control high water level of the lower reservoir and the dedicated reservoir through a global search. This invention, by systematically considering the flood process, power generation scheduling, and inter-reservoir hydraulic connections, effectively improves the accuracy of flood control calculations and engineering safety, providing a reliable basis for the flood control design of the lower reservoir of pumped-storage power stations with sediment-trapping dams. Attached Figure Description
[0022] Figure 1 A flowchart illustrating the flood control method for a pumped-storage power station involving water exchange between a lower reservoir and a dedicated reservoir, as claimed in this embodiment of the invention. Figure 2 A schematic diagram of the layout of the lower reservoir hub structures for flood control methods of pumped storage power stations that exchange water volume between the lower reservoir's sediment trap and the dedicated reservoir. Figure 3 A schematic diagram of the elevation layout of the lower reservoir hub structure for flood control methods in pumped storage power stations that exchange water volume between the lower reservoir's sediment trap and the dedicated reservoir. Detailed Implementation
[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0024] The terms "first," "second," and "third" in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.
[0025] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0026] According to the first embodiment of the present invention, referring to Figure 1 This invention claims protection for a flood control method for a pumped-storage power station involving water exchange between a lower reservoir's sediment trap and a dedicated reservoir, the method comprising: S1. Construct an engineering parameter database to structurally store the physical and hydraulic characteristic parameters of the pumped storage power station. The physical and hydraulic characteristic parameters include at least the natural flood hydrograph at the dam site, the storage capacity curve of the silt-trapping reservoir, the storage capacity curve of the dedicated reservoir, the discharge curve of the dam's spillway structure, the normal water level and the dead water level, and the rated power generation flow. S2, based on the parameters stored in the engineering parameter database, by discretizing and combining multiple uncertain factors affecting the flood control results, a state space set consisting of multiple independent calculation conditions covering all potential unfavorable combinations is constructed. S3, for each calculation condition in the state space set, nested iterative calculations are performed within the main time loop that advances over a preset time period to dynamically calculate the water balance between the sediment-trapping reservoir and the special reservoir throughout the flood process, analyze the dynamic water exchange between the two reservoirs through the spillway at the top of the sediment-trapping dam that is driven by the water level difference between the two, and output the highest water level of the sediment-trapping reservoir and the special reservoir during the entire flood process under each calculation condition; S4. Receive and store the highest water level under all calculation conditions, and after all calculation conditions are completed, determine the flood control high water level of the sediment-trapping reservoir and the flood control high water level of the special reservoir by performing a global maximum value search on all stored highest water levels of sediment-trapping reservoirs and the highest water levels of special reservoirs respectively.
[0027] In this embodiment, characteristic parameters of the pumped storage power station are obtained, wherein the characteristic parameters include at least the normal water level of the lower reservoir. Z n Dead water level in the lower reservoir Z d , reservoir capacity curve v 1 ( Z 1) Dedicated warehouse capacity curve v 2 ( Z 2) Discharge curve of the flood discharge and sediment flushing tunnel q ps ( Z 1) Spillway discharge curve of the sand-trapping dam Discharge curves of dam spillway structures q xs2 ( Z 2) Rated flow rate Q FD etc., in the formula Z 1 and Z 2 represents the water levels of the sediment-trapping reservoir and the dedicated reservoir, respectively.
[0028] Set the computation time and space parameters, including computation duration. T Time step Spatial step size .
[0029] Based on the natural flow process into the sediment-trapping reservoir, interpolation was performed to obtain... The natural flow process at the moment of entering the sediment-trapping reservoir Calculate the average natural inflow into the sediment-trapping reservoir for each time period. , .
[0030] Set the starting water level for the dedicated reservoir. Z 2,0 The starting water level must be higher than the dead water level. Z d Construct a power generation marker matrixD , for having n The column vector of the item uses a value of 1 to represent a period of power generation and a value of 0 to represent a period of no power generation. Considering unfavorable operating conditions and the actual operation of pumped storage power stations, the value 1 should appear continuously, and the power generation flag matrix... D The sum of the elements should be less than or equal to the quotient of the reservoir's achievable power generation flow and the rated power generation flow, forming the power generation indicator matrix. D The following conditions must be met:
[0031] In the formula: N Defined as the amount of electricity that can be generated from the upper reservoir. W sfd Defined as the amount of water available for power generation in the upper reservoir.
[0032] Based on the initial natural inflow into the sediment retention reservoir The starting water level of the sediment-trapping reservoir is calculated by comparing the discharge curve of the flood discharge and sediment-discharge tunnel. .
[0033] The main steps for calculating the water level of the sediment-trapping reservoir at the end of the time period are as follows: The initial water level of the silt-trapping reservoir is equal to the final water level of the previous period, that is... Assume the water level of the sediment-trapping reservoir at the end of the period is Z 1i,末 Based on the water level, the initial and final water volumes in the sediment-trapping reservoir during the time period are calculated using the reservoir capacity curve. , .
[0034] Based on the water level of the sediment-trapping reservoir, the initial and final discharge capacities for a given time period are calculated according to the discharge curve of the flood discharge and sediment flushing tunnel. , Calculate the average discharge capacity of the flood discharge and sediment flushing tunnel during different time periods. .
[0035] The initial discharge capacity of the spillway of the silt-trapping dam is equal to the final discharge capacity of the previous period, that is... Assuming the spillway capacity of the silt-trapping dam at the end of the period is Calculate the average discharge capacity of the spillway of the sand-trapping dam during different time periods. .
[0036] Based on the principle of water balance, calculation i Water volume in the sediment trap at the end of the period .
[0037] judge W 1i,末1 and W 1i,末2 Are they equal? If they are equal, then... i The calculation of the water level in the sediment-trapping reservoir at the end of the time period is completed; if they are not equal, the calculation will be changed.Z 1i,末 Repeat step S06.
[0038] The main steps for calculating the water level of the dedicated reservoir at the end of the time period are as follows: The initial water level of the dedicated reservoir during a given period is equal to the final water level of the previous period, i.e. Assume the water level at the end of the designated reservoir period is... Z 2i,末 Based on the water level, the initial and final water volumes in the sediment-trapping reservoir during the time period are calculated using the reservoir capacity curve. , .
[0039] Calculation period i Power generation flow, when power generation flag matrix D exist i Elements of time period and During this period, the pumped-storage power station generates electricity, and the power generation flow rate during this period is... .
[0040] Time period i At any given time, the dedicated reservoir may simultaneously experience inflows through the spillway of the silt-trapping dam, power generation flow from the upper reservoir, and outflows through the spillway structures of the dam. To ensure the proper functioning of the pumped storage power station, it is necessary to regulate the outflow through the gates of the spillway structures, ensuring that the power generation water remains in the dedicated reservoir. Analysis and calculations indicate the minimum water volume in the dedicated reservoir at the end of the time period. .
[0041] Based on the water level of the dedicated reservoir, the initial and final discharge capacities for a given time period are calculated according to the discharge curves of the dam's spillway structures. , .
[0042] To avoid causing man-made flooding downstream, the flow rate discharged through various spillway structures to the downstream of the dam must not exceed [a certain limit]. i Natural flood flow during and prior periods, i.e., the discharge structure of the dam. i Maximum discharge flow at the end of the period .
[0043] based on i Using data such as the maximum discharge flow of the dam's spillway structures, the spillway capacity of the silt-trapping dam, the power generation flow, and the capacity of the dedicated reservoir at the end of the time period, calculate the discharge flow of the dam's spillway structures at the end of the time period. .
[0044] Calculation period i Average discharge flow of the dam's spillway structures .
[0045] Based on the principle of water balance, the water volume in the dedicated reservoir at the end of the time period is calculated. .
[0046] judge W 2i,末1 and W 2i,末2 Are they equal? If they are equal, then... i The calculation of the water level in the dedicated reservoir at the end of the time period is completed; if they are not equal, the calculation will be changed. Z 2i,末 Repeat step S07.
[0047] The calculation based on the aforementioned steps i At the end of the time period, calculate the water level of the sediment-trapping reservoir and the dedicated reservoir, and calculate the head of the spillway of the sediment-trapping dam. :
[0048] in, Z yhd The elevation of the crest of the spillway of the sand-blocking dam.
[0049] Based on the water head of the spillway of the silt-retaining dam The spillway discharge curve was calculated to obtain i The spillway discharge capacity at the end of the period .
[0050] Determine the assumed spillway discharge capacity of the silt-trapping dam in step S06. Q yhdi,末1 The result calculated in step S09 Q yhdi,末2 If they are not equal, return to step S06 and adjust. Q yhdi,末1 Then recalculate.
[0051] If time period i If it is not the last time period, continue calculating the time period. i +1 until all time periods have been calculated.
[0052] Record the highest water levels of the sediment-trapping reservoir and the dedicated reservoir under the current starting water level of the dedicated reservoir and the power generation process conditions. Z 1maxpk,qj , Z 2maxpk,qj .
[0053] If not all possible power generation conditions have been traversed, then change the power generation flag matrix. D Calculation of working conditions j +1, until all power generation conditions have been calculated.
[0054] Records are based on the current starting water level and the highest water level of the sediment trap and dedicated reservoir under all possible power generation conditions. Z 1maxpk , Z2maxkp ,Right now , .
[0055] If not all possible starting water levels for dedicated reservoirs have been traversed, the starting water level is changed based on the set spatial step size, and the calculation conditions are adjusted accordingly. k +1, until all starting water level conditions have been calculated.
[0056] High water levels were obtained from the silt-trapping reservoirs and dedicated flood control reservoirs. Z 1max , Z 2max ,Right now , When the design standard natural inflow into the sediment-trapping reservoir is used, it is the design flood level; when the verification standard natural inflow into the sediment-trapping reservoir is used, it is the verification flood level.
[0057] Furthermore, the state space set constructed by S2 is spanned by at least three mutually orthogonal dimensions, namely: the initial water level of the dedicated reservoir, the start time of the power generation process of the upper reservoir, and the duration of the power generation process of the upper reservoir. The process of generating the state space set includes the following steps: Based on the dead water level and normal water level of the dedicated reservoir, and according to the preset water level spatial step size, the initial water level of the dedicated reservoir is discretized to generate an initial water level vector. Based on the total beneficial regulation capacity of the upper reservoir and the rated power generation flow of the generating units, the maximum continuous power generation duration is calculated. Combined with the total duration of the natural flood process line and the calculation period, by changing the starting position and sequence length of the continuous power generation sequence, a set of power generation flag matrices representing all possible power generation scheduling schemes is generated. Each of the power generation flag matrices is a one-dimensional binary vector, and its element values represent the start-up and shutdown status of the generating units in the corresponding period. The initial water level vector is combined with the set of power generation indicator matrices by performing a Cartesian product to generate the complete state space set.
[0058] Furthermore, the nested iterative calculations performed by S3 in each time period include an outer loop and an inner loop; The outer circulation is used to solve the exchange flow of the spillway of the silt-trapping dam at the end of the time period. The inner circulation is nested within the outer circulation and is used to solve the water level of the silt-trapping reservoir and the water level of the special reservoir at the end of the time period, respectively, given the exchange flow assumed by the outer circulation. The external circulation uses the spillway exchange flow rate at the end of the time period as the iteration variable, while the internal circulation uses the water level of the sediment trap and the water level of the special reservoir at the end of the time period as the iteration variables, respectively. Furthermore, referring to Figure 2In this embodiment, when determining the actual discharge flow from the silt-trapping dam to the river-blocking dam within a preset time period, step S3 applies at least one of the following constraints: Downstream flood control safety constraints stipulate that the total downstream discharge through dam structures must not exceed the upstream natural flood discharge at any given time; or The power station's operational safety constraints are implemented by adjusting the outflow from the dam to ensure that the water level in the dedicated reservoir is never lower than the reservoir capacity corresponding to its dead water level at any time.
[0059] Furthermore, the method also includes: When the natural flood hydrograph input during the construction of the engineering parameter database is the design standard flood hydrograph, the flood control high water level finally determined by the method is the design flood level of the silt-blocking dam and the river-blocking dam. When the natural flood process line input during the construction of the engineering parameter database is the verification standard flood process, the flood regulation high water level finally determined by the method is the verification flood level of the silt-blocking dam and the river-blocking dam. When calculating the aforementioned check flood level, an additional safety control logic check is performed before the start of the calculation for each time period: Check the water level of the dedicated reservoir at the end of the previous period. If the water level has exceeded the calculated design flood level of the dedicated reservoir, then forcibly set the power generation flag matrix elements of the current and all subsequent periods to zero to simulate an emergency shutdown of the unit.
[0060] Furthermore, in step S1, the discharge capacity of the spillway connecting the sediment-trapping reservoir and the dedicated reservoir is a function of the head, which is jointly determined by engineering parameters such as the water level of the sediment-trapping reservoir, the water level of the dedicated reservoir, and the elevation of the weir crest or bottom plate of the spillway. When the spillway is a spillway, the head and discharge capacity are calculated as follows:
[0061] In the formula, The water head represents the flow rate; a positive value indicates that water flows from the sediment-trapping reservoir into the dedicated reservoir, while a negative value indicates that water flows from the dedicated reservoir into the sediment-trapping reservoir. For the water level of the silt-trapping reservoir, For the dedicated reservoir water level, The elevation of the spillway crest of the sand-blocking dam. To improve the spillway discharge capacity of the sand-blocking dam, The relationship between the spillway discharge capacity of the sand-blocking dam and the water head above the dam; Reference Figure 3 In this embodiment, the overflow section of the dam is shown in the schematic diagram, and the crest elevation of the weir is designed.
[0062] Furthermore, the power generation indicator matrix is a column vector with n terms, where a value of 1 represents power generation during a period and a value of 0 represents no power generation during a period. For unfavorable considerations, the value 1 should appear consecutively. The matrix must meet the following requirements:
[0063]
[0064] In the formula, d i This is the generator generation status identifier for time period i. This refers to the hydroelectric flow rate of the upper reservoir. W sfd The amount of water available for power generation in the upper reservoir. Q FD Rated power generation flow rate, For calculating the time period, v 2 ( Z n (This refers to the reservoir's normal water level and corresponding capacity.) v 2 ( Z 2,0 (This refers to the water level of the dedicated reservoir at the initial calculation time.) Z 2,0 The corresponding storage capacity.
[0065] Furthermore, in step S3, the formula for calculating the power generation reference flow rate for the preset time period is: ; Q fdi This is the sum of the power generation flow from the previous period; In step S3, the amount of water required for pumped-storage power generation that the dedicated reservoir needs to retain needs to be considered, i.e., the minimum water volume in the dedicated reservoir at the end of the time period. The calculation formula is as follows:
[0066] Furthermore, in step S3, to avoid causing man-made flooding downstream, the flow rate discharged to the downstream of the dam must not exceed the natural flood flow rate before the preset time period, i.e., the maximum discharge flow rate of the spillway structure at the end of the time period. The calculation formula is as follows: .
[0067] In the formula, For natural flow processes, Q psi,末 This refers to the discharge capacity of the flood discharge and sediment flushing tunnel at the end of the period. Q xs2i,末0 This refers to the discharge capacity of the dam's spillway structure corresponding to the water level of the dedicated reservoir at the end of the time period.
[0068] Furthermore, in step S3, the formula for calculating the discharge flow at the end of the time period of the dam's spillway structure is as follows:
[0069] In the formula, The average discharge capacity of the spillway of the sand-blocking dam during different time periods. The initial water volume in the dedicated reservoir for that period. The initial discharge capacity of the dam's spillway structures during a given period.
[0070] In this embodiment, the process of iteratively calculating the water level of the sediment-trapping reservoir at the end of the time period is as follows: (11) Assumption i Water level at the end of the period Z 1i,末 Calculated based on the water level and capacity curve of the sediment-trapping reservoir i The water volume in the sediment-trapping reservoir at the beginning and end of the time period, i.e. ,in W 1i,初 / 末 for i The amount of water in the sediment trap at the beginning or end of a time period. v 1 shows the relationship between the storage capacity of the sediment-trapping reservoir and the changes in its water level. Z 1i,初 / 末 for i Water level of the sediment-trapping reservoir at the beginning or end of a time period; (12) Calculate the discharge capacity curve of the flood discharge and sediment flushing tunnel. i The discharge capacity at the beginning and end of the time period, i.e. Calculate the average discharge capacity of the flood discharge and sediment flushing tunnel during different time periods. ,in Q psi,初 / 末 for i The discharge capacity of the flood discharge and sediment flushing tunnel at the beginning or end of the time period. q ps The relationship between the discharge capacity of the flood discharge and sediment flushing tunnel and the water level of the sediment retention reservoir; (13) Assumption i The spillway discharge capacity of the sand-trapping dam at the end of the period Calculate the average discharge capacity of the spillway of the sand-trapping dam during different time periods. ; (14) Calculate the water balance of the sediment-trapping reservoir according to the principle of water balance. i Water volume at the end of the period, i.e. ,in W 天然入库 According to the natural flood at the site of the sand-trapping dam Q i calculate, W 通过泄水建筑物出库 Based on the average discharge capacity of the flood discharge tunnel and the spillway of the silt retention dam during different time periods , calculate; (15) Determine the results obtained from steps (11) and (14).W 1i,末 Are they equal? If they are equal, then... i The calculation of the water level in the sediment-trapping reservoir at the end of the time period is completed; if they are not equal, the calculation will be changed. Z 1i,末 Repeat steps (11) to (14) to calculate again.
[0071] The specific process of iteratively calculating the water level of the dedicated reservoir at the end of the time period is as follows: (21) Assumption i Water level at the end of the period Z 2i,末 Calculated based on the water level and capacity curve of the dedicated reservoir. i The water volume in the dedicated reservoir at the beginning and end of the time period, i.e. ,in W 2i,初 / 末 for i The water volume in the dedicated reservoir at the beginning or end of a time period. v 2. The relationship between the capacity of the dedicated reservoir and the changes in its water level. Z 2i,初 / 末 for i Water level in the dedicated reservoir at the beginning or end of a given time period; (22) According to the power generation indicator matrix D elements in d i Determine the time period i Whether or not electricity is generated depends on the amount of electricity generated. N and the cumulative generated flow of the preceding period Rated power generation flow rate, calculated for the time period i Power generation flow Q fdi ; (23) Considering that pumped storage power stations need to perform peak shaving and valley filling functions through pumping-power generation conversion, even in the event of a flood, the water volume in the dedicated reservoir cannot be completely discharged downstream through the spillway structures. The water volume required for power generation needs to be retained. That is, the amount of water required for power generation is calculated based on the water volume in the dedicated reservoir at the initial moment and the cumulative water volume generated during the time period. i Minimum water volume in the dedicated reservoir at the end of the time period W 2i,末min ; (24) To avoid man-made floods, the discharge flow of the dam's spillway structure shall not exceed the maximum natural inflow flow of the preceding period, based on the natural inflow flow of the preceding period. , i Discharge flow rate from the flood discharge and sediment flushing tunnel at the end of the period Q psi,末 , i Discharge capacity of the dam's spillway structures at the end of the period Q xs2i,末 = q xs2 (Z 2i,末 ),calculate i Maximum allowable discharge flow of the dam's spillway structure at the end of the period Q xs2i,末max ,in q xs2 The relationship between the discharge capacity of the dam's spillway structures and the water level of the dedicated reservoir; (25) The maximum allowable discharge flow of the dam's spillway structure based on the calculation. Q xs2i,末max Flood discharge of the sand-blocking dam spillway Q yhdi,末1 Power generation flow Q fdi Initial water volume of the dedicated reservoir during the period W 2i,初 and minimum water volume at the end of the period W 2i,末min Initial discharge flow of the dam's spillway structures during the same period Q xs2i,初 ,calculate i Discharge flow from the dam's spillway structures at the end of the time period Q xs2i,末 ; (26) Calculate the water balance of the dedicated reservoir according to the principle of water balance. i Water volume at the end of the period, i.e. ,in W 沙坝溢洪道入库 Based on the average flow rate during the time period when the spillway of the silt barrier enters the dedicated reservoir. calculate, W 拦河坝泄水建筑物出库 Based on the average discharge capacity of the dam's spillway structures over a given period calculate; (27) Determine the results calculated in steps (21) and (26). W 2i,末 Are they equal? If they are equal, then... i The calculation of the water level in the dedicated reservoir at the end of the time period is completed; if they are not equal, the calculation will be changed. Z 2i,末 Repeat steps (1) to (6) to calculate again; The specific process for adjusting the spillway discharge capacity of the silt-trapping dam is as follows: (31) Obtained according to the aforementioned steps i At the end of the period, the water level of the sediment-trapping reservoir Z 1i,末 Special reservoir water level 、 Z 2i,末 ,calculate ; (32) Based on the input spillway discharge capacity of the silt-trapping dam q ( The curve was calculated to obtain... i The spillway discharge capacity of the sand-trapping dam at the end of the period Q yhdi,末2 ; (33) Determine the average discharge capacity of the spillway Q yhdi,末2 Assuming in step F Q yhdi,末1 If they are equal, then continue to adjust. If the spillway discharge capacity of the sand-trapping dam is not equal during different time periods, then take the value of the spillway discharge capacity. Q yhdi,末1 The value is Q yhdi,末2 Repeat steps F and G to calculate again.
[0072] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.
[0073] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated units described above can be implemented in hardware or as software functional units. The above are merely embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made based on the description and drawings of this application, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
[0074] The specific embodiments of the invention have been described in detail above, but they are only examples, and this application is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications or substitutions to the invention are also within the scope of this application. Therefore, all equivalent changes, modifications, and improvements made without departing from the spirit and principles of this application should be covered within the scope of this application.
Claims
1. A flood control method for a pumped storage power station with water volume exchange between a sediment detention reservoir and a dedicated reservoir, characterized in that, The method comprises: S1, constructing an engineering parameter database, and structurally storing physical and hydraulic characteristic parameters of the pumped storage power station, the physical and hydraulic characteristic parameters at least including a natural flood hydrograph at a dam site of a sand retaining dam, a sand retaining reservoir capacity curve, a special reservoir capacity curve, a discharge curve of a discharge structure of the sand retaining dam, a normal storage level and a dead storage level, and a rated power generation flow rate; S2, based on the parameters stored in the engineering parameter database, constructing a state space set composed of multiple independent calculation conditions covering all potential adverse combinations by discretizing and combining multiple uncertainty factors affecting flood regulation results; S3, for each calculation condition in the state space set, performing nested iterative calculation in a main time loop advancing in a preset time period, dynamically calculating water balance of the sand retaining reservoir and the special reservoir in the entire flood process, analyzing dynamic water exchange between the two reservoirs driven by water level difference of the sand retaining dam through the spillway on the dam top, and outputting the highest water level of the sand retaining reservoir and the special reservoir in the entire flood process under each calculation condition; S4, receiving and storing the highest water level under all calculation conditions, and after all calculation conditions are calculated, determining the flood regulation high water level of the sand retaining reservoir and the flood regulation high water level of the special reservoir by respectively performing global maximum value searching on all stored highest water levels of the sand retaining reservoir and the special reservoir.
2. The method according to claim 1, characterized in that, The state space set constructed in S2 is formed by at least three mutually orthogonal dimensions, and the three dimensions are respectively an initial storage level of the special reservoir, a starting time of a power generation process of an upper reservoir, and a duration of the power generation process of the upper reservoir; The process of generating the state space set comprises the following steps: Discretizing the initial storage level of the special reservoir based on the dead storage level and the normal storage level of the special reservoir and according to a preset water level space step, and generating an initial water level vector; Based on the total beneficial regulation capacity of the upper reservoir and the rated power generation flow rate of the unit, the maximum continuous power generation total duration is calculated, and combined with the total duration of the natural flood hydrograph and the calculation period, the starting position and sequence length of the continuous power generation sequence are changed to generate a power generation flag matrix set representing all possible power generation scheduling schemes, wherein each power generation flag matrix is a one-dimensional binary vector, and the element value represents the start-stop state of the unit in the corresponding period; The initial water level vector and the power generation flag matrix set are combined by Cartesian product to generate the complete state space set.
3. The method according to claim 1, characterized in that, The nested iterative calculation performed by S3 in each period includes an outer loop and an inner loop; The outer loop is used to solve the spillway exchange flow at the end of the period, and the inner loop is nested in the outer loop and is used to solve the sand retaining reservoir water level and the special reservoir water level at the end of the period respectively under the condition of the exchange flow assumed by the outer loop; The outer loop takes the spillway exchange flow at the end of the period as an iterative variable, and the inner loop takes the sand retaining reservoir water level and the special reservoir water level at the end of the period as iterative variables respectively.
4. The method according to claim 3, characterized in that, When determining the actual discharge flow of the sand retaining dam in a preset period, S3 applies at least one of the following constraint conditions: The downstream river channel flood control safety constraint is that the total discharge of the discharge structure of the dam does not exceed the upstream natural flood flow at any moment. The power station operation safety constraint is that the water quantity in the special reservoir is not lower than the reservoir capacity corresponding to the dead water level at any moment by adjusting the discharge of the dam.
5. The method according to claim 3, characterized in that, Further comprising: When the natural flood hydrograph input in the construction process of the engineering parameter database is a design standard flood hydrograph, the flood regulation high water level finally determined by the method is the design flood level of the sand trap dam and the dam. When the natural flood hydrograph input in the construction process of the engineering parameter database is a checking standard flood hydrograph, the flood regulation high water level finally determined by the method is the checking flood level of the sand trap dam and the dam. In the calculation of the checking flood level, before the calculation of each period starts, additional safety control logic judgment is performed: The water level of the special reservoir at the end of the last period is checked, and if the water level has exceeded the design flood level of the special reservoir calculated, the power generation flag matrix elements of the current and subsequent periods are forced to be zero to simulate the emergency shutdown of the unit.
6. The method of claim 1, wherein the method is characterized by: In step S1, the discharge capacity of the discharge structure connecting the sand trap reservoir and the special reservoir is a function of the water head determined by the engineering parameters such as the water level of the sand trap reservoir, the water level of the special reservoir, and the crest elevation or bottom elevation of the discharge structure. When the discharge structure is a spillway, the water head and discharge capacity are calculated as follows: wherein, is the water head, positive value indicates that the reservoir water enters the special reservoir from the sand trap, negative value indicates that the reservoir water enters the sand trap from the special reservoir, is the water level of the sand trap, is the water level of the special reservoir, is the weir elevation of the sand trap spillway, is the discharge capacity of the sand trap spillway, is the relationship between the discharge capacity of the sand trap spillway and the water head on the weir.
7. The method according to claim 2, wherein the method is characterized in that, The power generation flag matrix is a column vector with n items, and the value 1 indicates power generation in the period, and the value 0 indicates no power generation in the period. In order to consider the adverse case, the value 1 should be continuous, and the matrix should meet the following requirements: wherein d i is the period i power generation state identifier, is the upper reservoir available power generation flow, W sfd is the upper reservoir available power generation water volume, Q FD is the rated power generation flow, is the calculation period, v 2( Z n ) is the corresponding reservoir capacity of the normal water level of the special reservoir, v 2( Z 2,0 ) is the water level of the special reservoir at the initial moment of calculation Z 2,0 corresponding reservoir capacity.
8. The method according to claim 1, characterized in that, In step S3, the calculation formula of the power generation reference flow of the preset period is: ； Q fdi is the sum of the generation flows for the previous time period; In step S3, the water quantity required for pumped storage power generation in the special reservoir needs to be considered, that is, the minimum water quantity in the special reservoir at the end of the period, and the calculation formula is: 。 9. The method for calculating the flood regulation of the pumped storage power station with the water exchange between the sand trap of the lower reservoir and the special reservoir according to claim 1, characterized in that, In step S3, in order to avoid causing downstream artificial flood, the discharge to the downstream of the dam cannot exceed the natural flood flow before the preset period, that is, the maximum discharge of the discharge structure at the end of the period, and the calculation formula is: In the formula, is the natural flow process, Q psi,末 is the discharge capacity of the flood discharge and sediment discharge tunnel at the end of the period, Q xs2i,末0 is the discharge capacity of the discharge structure of the dam corresponding to the special reservoir water level at the end of the period.
10. The method for calculating the flood regulation of a pumped storage power station with water exchange between a sand trap of a lower reservoir and a dedicated reservoir according to claim 1, characterized in that, In step S3, the calculation formula of the discharge of the dam discharge structure at the end of the period is: In the formula, is the average discharge capacity of the spillway of the sand trap dam during the period, is the initial water volume in the special reservoir during the period, is the initial discharge capacity of the discharge structure of the dam during the period.