Stepwise modification method for reservoir flood control scheduling scheme

Abstract

This invention provides a stepped correction method for reservoir flood control scheduling schemes, comprising the following steps: obtaining the outflow from the reservoir at various time periods based on a reservoir flood control scheduling model; smoothing the outflow, calculating the slope and intercept within the stepped window, and determining the correction scheme based on the slope and the allowable outflow amplitude within the stepped window; generating a new scheduling scheme based on the corrected outflow for each time period within each stepped window. This invention, by introducing a stepped correction strategy, smooths the outflow obtained from the reservoir scheduling model, avoiding abrupt changes and sawtooth fluctuations in the outflow. It also considers various boundary conditions and influencing factors, making the corrected scheme more consistent with actual conditions and providing more scientific and reasonable decision support for reservoir scheduling.

Description

Technical Field

[0001] This invention relates to the field of reservoir scheduling decision-making technology, specifically to a step-by-step correction method for reservoir flood control scheduling schemes. Background Technology

[0002] Reservoir flood control scheduling refers to the planned control and regulation of floods using the storage and control capabilities of reservoirs to avoid flood damage in downstream flood control areas. Currently, research on reservoir flood control scheduling mainly focuses on the theoretical aspects of scheduling methods, neglecting in-depth discussions on the rationality and practicality of the calculation results of scheduling models. This bias often leads to calculation schemes being difficult to directly apply in practice and provide effective decision support.

[0003] Specifically, in the field of reservoir flood control scheduling, the solutions obtained from both optimization and rule-based scheduling models may encounter abrupt changes and sawtooth fluctuations in the discharge flow (i.e., the decision variable). In practice, these abrupt changes and sawtooth fluctuations increase the difficulty of reservoir scheduling and operational challenges, potentially affecting reservoir flood control safety, exacerbating downstream flood risks, and causing ecological damage. For optimization scheduling models, the algorithm may generate discontinuous search paths due to the complexity of the objective function and the diversity of constraints, leading to abrupt changes and sawtooth fluctuations in the discharge flow. For rule-based scheduling models, scheduling procedures are typically based on reservoir inflow conditions and the water level and flow conditions of downstream protected objects. However, these procedures are often coarse-grained, resulting in frequent alternations of scheduling procedures when conditions change between adjacent time periods, thus causing fluctuations in the discharge flow.

[0004] Therefore, how to solve the problem of sudden changes and sawtooth fluctuations in the discharge flow of the reservoir flood control scheduling model calculation scheme, and improve the practicality and accuracy of the scheduling model, is a technical problem that urgently needs to be solved in the field of reservoir management. Summary of the Invention

[0005] To overcome the shortcomings of the above-mentioned technologies, the purpose of this invention is to provide a step-like correction method for the results of reservoir flood control scheduling schemes. This method solves the problem of sudden changes and sawtooth fluctuations in the downstream flow (i.e., decision variables) that traditional reservoir flood control scheduling models may encounter when facing uncertain boundary conditions and highly nonlinear characteristics, thereby improving the practicality and accuracy of the model.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A step-wise correction method for a reservoir flood control scheduling scheme includes the following steps:

[0008] 1) Based on the reservoir flood control scheduling model, obtain the reservoir flood control scheduling scheme; the reservoir flood control scheduling scheme includes the outflow from the reservoir at different time periods;

[0009] 2) The outflow from the reservoir at each time period is smoothed to obtain the smoothed outflow from each time period;

[0010] 3) Set the reservoir scheduling tiered window and the allowable outflow operation range within the tiered window; the tiered window is the time period used for correction, and the operation range refers to the allowable change in outflow within the tiered window;

[0011] 4) Calculate the slope and intercept of the outbound flow rate for each time period after smoothing within each stepped window;

[0012] 5) Determine whether the slope is greater than the allowable outflow rate of the reservoir within the corresponding stepped window;

[0013] 5.1) If the slope is less than or equal to the allowable outflow range of the reservoir within the stepped window, the average outflow after smoothing within the stepped window shall be used as the corrected outflow for each time period within the stepped window.

[0014] 5.2) If the slope is greater than the allowable outflow range within the stepped window, recalculate the new slope, intercept, and outflow based on the stepped window and the initial outflow within the stepped window, and determine whether the new outflow satisfies the constraints:

[0015] a) If the new outbound flow does not meet the constraints, return to step 2), and smooth the outbound flow of each time period after smoothing in step 2) again according to the constraints, and then proceed to steps 3) to 5) in sequence.

[0016] b. If the new outbound flow rate meets the constraints, the outbound flow rate will be increased or decreased at the rate of the absolute value of the newly calculated slope.

[0017] 6) Generate a new scheduling plan based on the revised outflow for each time period within each stage window of the reservoir.

[0018] Furthermore, the reservoir flood control scheduling model includes an optimized scheduling model.

[0019] As a preferred option, in step 2), the smoothing process uses the moving average method.

[0020] Furthermore, the smoothing process uses the following formula:

[0021]

[0022] In the formula, N is the size of the smooth moving window, which is determined according to actual needs; Y i Q represents the smoothed outbound flow rate for time period i; i Let i be the outflow from the reservoir during time period i in the aforementioned reservoir flood control scheduling scheme.

[0023] Further, in step 3), the reservoir scheduling tiered window M and the allowable outflow operation amplitude (allowQ) within the tiered window are set according to the actual situation of reservoir scheduling; the tiered window refers to the number of time periods for one correction calculation, and the operation amplitude refers to the outflow amplitude within the tiered window. It can also be understood that the tiered window refers to the duration for which the reservoir can operate according to a fixed procedure, and the operation amplitude refers to the outflow amplitude for which the reservoir can operate according to a fixed procedure.

[0024] As a preferred embodiment, in step 4), the slope and intercept are calculated using the least squares method.

[0025] Furthermore, the formula for calculating the slope is as follows:

[0026]

[0027] The formula for calculating the intercept is:

[0028]

[0029] In the formula, This represents the average outbound flow rate for each time period within the stepped window M after smoothing. Y represents the average value of each time period i within the stepped window M; i0 represents the initial time period within the stepped window M; i This represents the outbound flow rate after smoothing within time period i in the stepped window.

[0030] Preferably, the duration of the time period is 1 hour.

[0031] As a preferred option, in step 5), if the slope is greater than the allowable outflow range of the reservoir within the stepped window, the new outflow Y... new The calculation formula is as follows:

[0032]

[0033] in, For the new slope, = is the new intercept.

[0034] if The slope and intercept of the outbound flow settings need to be reassigned to resolve the inconsistency between the first and last values ​​of the outbound flow settings in the stepped windows.

[0035] Furthermore, the new slope and new intercept The calculation formula is as follows:

[0036]

[0037] in, Y begin This represents the corrected outbound flow rate for the last period of the previous tier window.

[0038] As a preferred embodiment, in step 5), the constraints include the relationship between flow rate and amplitude in adjacent time periods, the constraints of maximum and minimum outflow, the water balance relationship, the water level-storage capacity relationship, and non-negative constraints.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] This invention introduces a stepped correction strategy to smooth the outflow from the reservoir by the reservoir scheduling model, avoiding abrupt changes and sawtooth fluctuations in the outflow. It also considers various boundary conditions and influencing factors, making the corrected scheme more in line with the actual situation and providing more scientific and reasonable decision support for reservoir scheduling. Attached Figure Description

[0041] Figure 1 A flowchart of a stepped correction method for a reservoir flood control scheduling scheme in this invention;

[0042] Figure 2 This is a comparison chart of the original outflow from the reservoir in the reservoir scheduling model and the outflow after correction using the method of this invention. Detailed Implementation

[0043] To better explain the present invention, the main contents of the present invention are further illustrated below with reference to the accompanying drawings and specific embodiments, but the contents of the present invention are not limited to the following embodiments.

[0044] Example

[0045] The outflow data of a certain water conservancy project was obtained by solving an optimized scheduling model for 72 time periods, each 1 hour long, during the No. 2 flood of 2024 in a certain river basin from 16:00 on April 20, 2024 to 15:00 on April 23, 2024. The outflow was corrected using a stepped correction method for reservoir flood control scheduling according to the present invention. The processing method is as follows: Figure 1 As shown, it includes the following steps:

[0046] 1) Obtain the outbound flow data obtained from the optimized scheduling model, with a time period of 1 hour.

[0047] 2) Solve for the outflow Q of the reservoir operation model using the moving average method.i Smoothing is performed using the formula. Obtain the smoothed outbound flow rate Y for each time period i In this embodiment, N = 5h.

[0048] 3) Set the reservoir dispatching tiered window M=12h and the allowable outflow operation amplitude within the tiered window allowQ=30m. 3 / s.

[0049] 4) The smoothed outbound flow rate Y t The slope and intercept within each step window are calculated using the least squares method according to the following formula:

[0050]

[0051] For example, there is a time series as shown in Table 1.

[0052] Time period i 1 2 3 4 5 6 7 <![CDATA[Outbound flow Y i > 10 12 14 16 18 20 22 ......

[0053] Five time periods are selected as the stepped window for outbound flow correction, i.e., M=5;

[0054] Within the first stepped window M, i0 = 1, the average value of i in each time period is...

[0055] Average outbound flow

[0056] The next corrected stepped window period is 6 to 10, then i0 = 6, and the average value of i in each period is...

[0057] In this embodiment, M = 12h, and the slope and intercept within each stepped window are calculated using the method described above.

[0058] 5) Determine the slope within each stepped window M. Is it greater than allowQ?

[0059] 5.1) If New outbound flow Y new Based on average outbound flow Control the leakage.

[0060] 5.2) If The slope and intercept settings for outbound flow need to be reassigned to resolve the inconsistency between the first and last values ​​of outbound flow across different stepped windows. The new slope and intercept are calculated using the following formula:

[0061]

[0062] in, Outbound flow according to To take control.

[0063] Determine the outbound flow Y new Do the following conditions be met: the relationship between flow rate and amplitude in adjacent time periods, the constraints of maximum and minimum outflow, the water balance relationship, the water level-storage capacity relationship, and the non-negative constraint conditions?

[0064] a) If the outbound flow rate Y new If the above constraints are not met, return to step 2), and then smooth the outbound flow of each time period after smoothing in step 2) again according to the constraints, and then proceed to steps 3) to 5 in sequence.

[0065] b. If the outbound flow rate Y new If the above constraints are met, the dispatching process is generated based on the new outflow rates for each time period within each step window M of the reservoir. The absolute value of the newly recalculated slope is used to determine the increase or decrease of the outflow rate in adjacent time periods. When the newly recalculated slope is greater than zero, the outflow rate is increased; when it is less than zero, the outflow rate is decreased. The absolute value of the newly recalculated slope is the process value for each change in outflow rate.

[0066] Finally, the time period i is matched with the scheduling time to obtain the outbound flow after time correction for each time period of the scheduling period.

[0067] The results of the reservoir scheduling model and the outflow results after correcting the results of the reservoir scheduling model using the above method are shown in Table 1 and 2. Figure 2 As shown.

[0068] The scheduling time represents 1 hour of the current time. For example, 2024-04-2016 represents 16:00 to 17:00 on April 20, 2024.

[0069] Table 1: Reservoir Dispatch Model Outflow and Corrected Outflow, and Reference Dispatch Order Table

[0070]

[0071]

[0072]

[0073] like Figure 2As shown in Table 1, the model-calculated outflow (orange line) illustrates the trend of outflow under the model-calculated outflow method. Significant fluctuations in flow are observed in certain periods, making it unsuitable for guiding actual reservoir operation. The stepped outflow (blue dashed line) shows the outflow variation under flood control conditions. It can be seen that the flow variation differs significantly from the other two outflow methods within a specific time period. By introducing a stepped correction strategy, the outflow calculated by the reservoir operation model is smoothed, avoiding abrupt changes and sawtooth fluctuations in outflow. Furthermore, considering various boundary conditions and influencing factors, the corrected scheme better reflects actual operation.

[0074] This example provides a stepwise correction method for the results of a reservoir flood control scheme. Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by computer program instructions to related hardware. Those skilled in the art can make certain modifications to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; however, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions in the embodiments of this application, and should all be included within the protection scope of this application.

[0075] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all combinations of the technical features in the above embodiments are described. The above embodiments only illustrate one implementation method of the present invention, and their descriptions are relatively specific and detailed. They should not be construed as limiting the scope of the present invention. The present invention is not limited to the above optional implementation methods. All modifications, equivalent substitutions, and improvements made within the scope defined by the claims of the present invention should be included within the protection scope of the present invention.

Claims

1. A step-wise correction method for a reservoir flood control scheduling scheme, characterized in that: Includes the following steps: 1) Based on the reservoir flood control scheduling model, obtain the reservoir flood control scheduling scheme; The reservoir flood control scheduling plan includes the outflow from the reservoir at different times; 2) The outflow from the reservoir at each time period is smoothed to obtain the smoothed outflow from each time period; 3) Set the reservoir scheduling tiered window and the allowable outflow operation range within the tiered window; the tiered window is the time period used for correction, and the operation range refers to the allowable change in outflow within the tiered window; 4) Calculate the slope and intercept of the outbound flow rate for each time period after smoothing within each stepped window; 5) Determine whether the slope is greater than the allowable outflow rate of the reservoir within the corresponding stepped window; 5.1) If the slope is less than or equal to the allowable outflow range of the reservoir within the stepped window, the average outflow after smoothing within the stepped window shall be used as the corrected outflow for each time period within the stepped window. 5.2) If the slope is greater than the allowable outflow range within the stepped window, recalculate the new slope, intercept, and outflow based on the stepped window and the initial outflow within the stepped window, and determine whether the new outflow satisfies the constraints: a) If the new outbound flow does not meet the constraints, return to step 2), and smooth the outbound flow of each time period after smoothing in step 2) again according to the constraints, and then proceed to steps 3) to 5) in sequence. b. If the new outbound flow rate meets the constraints, the outbound flow rate will be increased or decreased at the rate of the absolute value of the newly calculated slope. 6) Generate a new scheduling plan based on the revised outflow for each time period within each stage window of the reservoir.

2. The step-like correction method according to claim 1, characterized in that: The reservoir flood control scheduling model includes an optimized scheduling model.

3. The step-like correction method according to claim 1, characterized in that: In step 2), the smoothing process uses the moving average method.

4. The step-like correction method according to claim 3, characterized in that: The smoothing process uses the following formula: In the formula, N is the size of the smooth moving window, which is determined according to actual needs; Y i Q represents the smoothed outbound flow rate for time period i; i Let i be the outflow from the reservoir during time period i in the aforementioned reservoir flood control scheduling scheme.

5. The step-like correction method according to claim 1, characterized in that: In step 3), the reservoir scheduling tiered window M and the allowable outflow operation amplitude allowQ within the tiered window are set according to the actual situation of reservoir scheduling.

6. The step-like correction method according to claim 1, characterized in that: In step 4), the slope and intercept are calculated using the least squares method.

7. The step-like correction method according to claim 6, characterized in that: The formula for calculating the slope is as follows: The formula for calculating the intercept is: In the formula, This represents the average outbound flow rate for each time period within the stepped window M after smoothing. Y represents the average value of each time period i within the stepped window M; i0 represents the initial time period within the stepped window M; i This represents the outbound flow rate after smoothing within time period i in the stepped window.

8. The step-like correction method according to claim 1, characterized in that: The duration of the time period is 1 hour.

9. The step-like correction method according to claim 7, characterized in that: In step 5), if the slope is greater than the allowable outflow range of the reservoir within the stepped window, the new outflow Y is... new The calculation formula is as follows: in, For the new slope, This is the new intercept.

10. The step-like correction method according to claim 9, characterized in that: The new slope and new intercept The calculation formula is as follows: in, Y begin This represents the corrected outbound flow rate for the last period of the previous tier window.

11. The step-like correction method according to any one of claims 1 to 10, characterized in that: In step 5), the constraints include the relationship between flow rate and amplitude in adjacent time periods, the constraints of maximum and minimum outflow, the water balance relationship, the water level-storage capacity relationship, and non-negative constraints.

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