Step-shaped correction method for reservoir flood control scheduling scheme

Abstract

The invention provides a stepped correction method for a reservoir flood control scheduling scheme, and the method comprises the following steps: obtaining the discharge flow of a reservoir in each time period based on a reservoir flood control scheduling model; smooth processing is carried out on the ex-reservoir flow, the slope and the intercept in the step window are calculated, and a correction scheme is determined according to the slope and the variable amplitude of the ex-reservoir flow allowed by the reservoir in the step window; and generating a new scheduling scheme according to the corrected new ex-reservoir flow in each time period in each step window of the reservoir. According to the method, the stepped correction strategy is introduced, the reservoir outlet flow solved by the reservoir scheduling model is smoothed, sudden change and zigzag fluctuation of the reservoir outlet flow are avoided, multiple boundary conditions and influence factors are considered at the same time, the corrected scheme is more in line with the actual situation, and the method is suitable for large-scale popularization and application. And more scientific and reasonable decision support is provided for reservoir dispatching.

Description

Technical Field

[0001] The invention relates to the technical field of reservoir dispatching decision-making, and in particular to a step-wise correction method for a reservoir flood control dispatching scheme. Background Art

[0002] Reservoir flood control dispatching refers to the use of the reservoir's regulation and control capabilities to control and regulate floods in a planned manner to avoid flood losses in downstream flood control areas. At present, the research on reservoir flood control dispatching mainly focuses on the dispatching method theory, but ignores the in-depth discussion on the rationality and practicability of the dispatching model calculation results. This bias often makes it difficult to directly apply the calculation scheme results in practical applications and provide effective decision support.

[0003] Specifically, in the field of reservoir flood control scheduling, the solution results of the optimization scheduling model and the rule scheduling model may encounter the problem of sudden changes and sawtooth fluctuations in the downstream flow (i.e., decision variables). In actual operation, the sudden changes and sawtooth fluctuations in the downstream flow will increase the difficulty of reservoir scheduling and operation difficulties, and may also affect the flood control safety of the reservoir, and aggravate the risk of downstream flood disasters and cause ecological damage. For the optimization scheduling model, the optimization algorithm may produce discontinuous search paths in the process of finding the optimal solution due to the complexity of the objective function and the diversity of constraints, resulting in sudden changes and sawtooth fluctuations in the downstream flow. For the rule scheduling model, the scheduling procedures are usually formulated based on the reservoir inlet conditions and the water level and flow conditions of the downstream protection objects, but the granularity is often coarse when formulating the procedures, resulting in frequent alternations of the scheduling procedures when the scheduling conditions change between adjacent time periods, which in turn causes the downstream flow to fluctuate back and forth.

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

[0005] In order to overcome the shortcomings of the above-mentioned technology, the purpose of the present invention is to provide a step-by-step correction method for the results of reservoir flood control scheduling schemes, so as to solve the problems of sudden changes and jagged fluctuations in the discharge flow (i.e., decision variables) that may be encountered in the calculation results of traditional reservoir flood control scheduling models when facing uncertain boundary conditions and highly nonlinear characteristics, thereby improving the practicability and accuracy of the model.

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

[0007] A stepwise correction method for a reservoir flood control scheduling scheme comprises the following steps:

[0008] 1) Based on the reservoir flood control dispatching model, a reservoir flood control dispatching plan is obtained; the reservoir flood control dispatching plan includes the outflow of the reservoir in each period;

[0009] 2) Smoothing the outflow of the reservoir in each period to obtain the outflow of each period after smoothing;

[0010] 3) Setting the reservoir dispatching step window and the allowable outflow flow operating range of the reservoir within the step window; the step window is the length of the time period adopted for correction, and the operating range refers to the allowable change range of the outflow flow within the step window;

[0011] 4) Calculating the outbound flow in each time period after smoothing in each step window to obtain the slope and intercept in the step window;

[0012] 5) determining whether the slope is greater than the allowable outflow operation amplitude of the reservoir in the corresponding step window;

[0013] 5.1) If the slope is ≤ the allowable outflow range of the reservoir in the step window, the average outflow after smoothing in the step window is used as the corrected outflow for each period in the step window;

[0014] 5.2) If the slope is greater than the allowable outflow range in the step window, the new slope, intercept and outflow are recalculated based on the step window and the initial outflow in the step window, and it is determined whether the new outflow meets the constraints:

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

[0016] b. If the new outbound flow meets the constraint conditions, the outbound flow is increased or decreased at the rate of the recalculated absolute value of the new slope;

[0017] 6) Generate a new dispatching plan based on the revised new outflow flow in each time period within each step window of the reservoir.

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

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

[0020] Furthermore, the formula used in the smoothing process is as follows:

[0021]

[0022] Where N is the size of the smooth moving window, which is determined according to actual needs; Y i is the outbound flow in period i after smoothing; Q i It is the outflow flow in period i in the reservoir flood control scheduling plan.

[0023] Further, in step 3), the reservoir dispatching step window M and the reservoir allowed outflow flow operating amplitude allowQ in the step window are set according to the actual situation of reservoir dispatching; the step window refers to the number of time periods for a correction calculation, and the operating amplitude refers to the outflow flow amplitude within the step window. It can also be understood that the step window refers to the length of time that the reservoir can be operated according to a certain set of fixed procedures, and the operating amplitude refers to the outflow flow amplitude that the reservoir can operate according to a certain set of fixed procedures.

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

[0025] Furthermore, the calculation formula of the slope is as follows:

[0026]

[0027] The calculation formula of the intercept is:

[0028]

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

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

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

[0032]

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

[0034] if The slope and intercept of the outbound flow setting need to be reassigned to solve the problem of inconsistent settings of the first and last values ​​of the outbound flow between step windows.

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

[0036]

[0037] in, Y begin Represents the corrected outbound flow in the last period of the previous step window of the current step window.

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

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The present invention introduces a step-by-step correction strategy to smooth the outflow flow solved by the reservoir scheduling model, avoiding sudden changes and sawtooth fluctuations in the outflow flow. At the same time, it takes into account a variety of boundary conditions and influencing factors, making the corrected plan more in line with the actual situation and providing more scientific and reasonable decision support for reservoir scheduling. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a flow chart of a step-wise correction method of a reservoir flood control scheduling scheme in the present invention;

[0042] Figure 2 It is a comparison diagram of the original outflow of the reservoir dispatching model and the outflow after correction by the method of the present invention. DETAILED DESCRIPTION

[0043] In order to better explain the present invention, the main contents of the present invention are further explained below in conjunction with the drawings and specific embodiments, but the contents of the present invention are not limited to the following embodiments.

[0044] Example

[0045] The outflow flow data of a water conservancy hub was solved by the optimization scheduling model for 72 time periods of 1 hour from 16:00 on April 20, 2024 to 15:00 on April 23, 2024 during the No. 2 flood in a certain basin in 2024. The outflow flow was corrected by a step-by-step correction method of a reservoir flood control scheduling scheme of the present invention. The processing method is as follows: Figure 1 As shown, the following steps are included:

[0046] 1) Obtain the outbound flow data solved by the optimization scheduling model, and the duration of the time period is 1 hour.

[0047] 2) Using the moving average method to solve the outflow flow Q of the reservoir operation modeli Smoothing is performed using the formula Get the outbound flow Y after smoothing in each period i In this embodiment, N=5h.

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

[0049] 4) Smoothed outbound flow Y t The slope and intercept in each step window are calculated by the least square method according to the following formula:

[0050]

[0051] For example: There is a time series as shown in Table 1

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

[0053] Select 5 time periods as the step windows for outbound flow correction, i.e., M = 5;

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

[0055] Average outbound flow

[0056] The next modified step window period is 6 to 10, then i0 = 6, and the average value of each period i

[0057] In this embodiment, M=12h, and the slope and intercept in each step window are calculated by referring to the above method.

[0058] 5) Determine the slope of each step window M Is it greater than allowQ?

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

[0060] 5.2) If The slope and intercept of the outbound flow setting need to be reassigned to solve the problem of inconsistent settings of the first and last values ​​of the outbound flow between step windows; the new slope and intercept are calculated according to the following formula:

[0061]

[0062] in, Outbound flow rate Take control.

[0063] Determine the outbound flow Y new Whether the relationship between flow and amplitude in adjacent periods, the maximum and minimum outflow constraints, the water balance relationship, the water level-storage capacity relationship and the non-negative constraints are met:

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

[0065] b. If the outbound flow is Y new If the above constraints are met, the dispatching process is generated according to the new outflow in each period in each step window M of the reservoir, and the outflow is increased or decreased with the absolute value of the recalculated new slope as the change in the adjacent period. When the recalculated new slope is greater than zero, the outflow is increased, and when it is less than zero, the outflow is reduced. The absolute value of the recalculated new slope is the process value of each outflow change.

[0066] Finally, time period i is matched with the scheduling time to obtain the corrected outbound flow at each time during the scheduling period.

[0067] The results of the reservoir operation model and the outflow results after the results of the reservoir operation model are corrected by the above method are shown in Table 1 and Figure 2 shown.

[0068] The scheduling time represents 1 hour of the current time, such as 2024-04-2016 represents 16:00~17:00 on 2024-04-20.

[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 solves the outflow (orange line): This curve shows the changing trend of the outflow flow under the model calculation outflow method. It can be observed that the flow has fluctuated significantly in certain periods and cannot guide the actual scheduling of the reservoir. Step-shaped outflow (blue dotted line): This curve shows the change of outflow flow under flood control conditions. It can be seen that within a specific time period, the change in flow is significantly different from the other two outflow methods. By introducing a step-shaped correction strategy, the outflow flow solved by the reservoir scheduling model is smoothed to avoid sudden changes and jagged fluctuations in the outflow flow. At the same time, a variety of boundary conditions and influencing factors are considered, making the corrected scheme more in line with the actual scheduling situation.

[0074] This example provides a step-by-step correction method for the results of a reservoir flood dispatching scheme. A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by computer program instructions and related hardware. A person skilled in the art can make certain modifications to the technical solutions recorded in the above-mentioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should be included in the protection scope of this application.

[0075] The technical features of the above-described embodiments can be combined arbitrarily. To make the description concise, not all combinations of the technical features in the above-described embodiments are described. The above-described embodiment only expresses one of the implementation methods of the method of the present invention. The description is relatively specific and detailed and should not be understood as limiting the scope of the patent of the present invention. The present invention is not limited to the above-described optional implementation methods. All modifications, equivalent substitutions and improvements made within the scope of the claims of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A step-wise correction method for a reservoir flood control scheduling scheme, characterized in that: The following steps are involved: 1) Based on the reservoir flood control operation model, obtain the reservoir flood control operation plan; The reservoir flood control dispatching plan includes the outflow of the reservoir in each period; 2) Smoothing the outflow of the reservoir in each period to obtain the outflow of each period after smoothing; 3) Setting the reservoir dispatching step window and the allowable outflow flow operating range of the reservoir within the step window; the step window is the length of the time period adopted for correction, and the operating range refers to the allowable change range of the outflow flow within the step window; 4) Calculating the outbound flow in each time period after smoothing in each step window to obtain the slope and intercept in the step window; 5) determining whether the slope is greater than the allowable outflow operation amplitude of the reservoir in the corresponding step window; 5.1) If the slope is ≤ the allowable outflow range of the reservoir in the step window, the average outflow after smoothing in the step window is used as the corrected outflow for each period in the step window; 5.2) If the slope is greater than the allowable outflow range in the step window, the new slope, intercept and outflow are recalculated based on the step window and the initial outflow in the step window, and it is determined whether the new outflow meets the constraints: a. If the new outbound flow does not meet the constraint conditions, return to step 2), smooth the outbound flow of each time period after smoothing in step 2) again according to the constraint conditions, and then proceed to steps 3) to 5) in sequence; b. If the new outbound flow meets the constraint conditions, the outbound flow is increased or decreased at the rate of the recalculated absolute value of the new slope; 6) Generate a new dispatching plan based on the revised new outflow flow in each time period within each step window of the reservoir.

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

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

4. The step correction method according to claim 3, characterized in that: The formula used in the smoothing process is as follows: Where N is the size of the smooth moving window, which is determined according to actual needs; Y i After smoothing i Outbound flow in period i; Q i It is the outflow flow in period i in the reservoir flood control scheduling plan.

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

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

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

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

9. The step correction method according to claim 1, characterized in that: In step 5), if the slope is greater than the reservoir’s allowed outflow range within the step window, the new outflow Y new The calculation formula is as follows: in, is the new slope, = is the new intercept.

10. The step correction method according to claim 9, characterized in that: The new slope and the new intercept The calculation formula is as follows: in, Y begin Represents the corrected outbound flow in the last period of the previous step window of the current step window.

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

Images