Cascade reservoir water level control node extraction method based on energy storage scheduling graph

Abstract

The invention discloses a cascade reservoir water level control node extraction method based on an energy storage scheduling graph, and belongs to the technical field of reservoir scheduling. The method comprises the following steps: firstly, constructing an energy storage scheduling graph of cascade reservoir scheduling, wherein the energy storage scheduling graph comprises an energy storage scheduling line, an up-down scheduling line and an output increasing / reducing line corresponding to output; simulating a historical long-sequence water level process based on the energy storage scheduling graph, and counting the upper limit, the lower limit and the mean value of the water level in each ten days in the year; meanwhile, calculating the same characteristic value of each ten-day of the historical actual water level measurement process; and finally, simulating a water level process according to a cascade reservoir scheduling procedure, a historical water level process and an energy storage scheduling graph, and extracting a water level control node rule in different periods, namely, taking the scheduling procedure as a core in a flood season and supplementing missing periods, and adopting a comprehensive calculation result in a non-flood season. According to the method, the multi-dimensional information is fused, the cascade reservoir water level node control interval is fully grasped, the scheduling time node is optimized, and the comprehensive benefit of cascade reservoir combined scheduling is effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of reservoir scheduling technology, and specifically relates to a method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams. Background Technology

[0002] In reservoir operation, water level control nodes are crucial for ensuring flood control safety and water resource benefits. Existing methods for extracting water level control nodes have significant limitations: First, they rely on operation procedures, but these procedures have a wide control granularity and are difficult to dynamically adjust, resulting in insufficient precision in operation. Second, they rely solely on historical water level characteristics, lacking optimal representativeness under typical scenarios, making it difficult to improve overall benefits. Third, they do not consider the energy storage characteristics of cascade reservoirs, failing to meet the energy balance and water allocation needs in joint operation. Fourth, their time-specific control strategies for flood season and non-flood season are incomplete and have limited applicability.

[0003] Therefore, the present invention aims to solve the technical problem that existing methods are difficult to effectively support the joint operation of cascade reservoirs. Summary of the Invention The technical problem to be solved by this invention is to provide a method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams. By controlling water level nodes in a diversified and time-segmented manner, the method can fully grasp the water level control intervals of cascade reservoirs, and reasonably optimize the time nodes for cascade reservoir scheduling. This method can effectively improve the overall benefits of cascade reservoir scheduling.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams, comprising the following steps: S1, Construct the energy storage scheduling diagram for cascade reservoir operation; S2, based on the energy storage scheduling diagram, simulates the water level process of a long historical sequence and calculates the water level characteristic values ​​at each time node; S3, calculate the characteristic values ​​of each time point in the historical water level process; S4, based on the cascade reservoir operation regulations, historical water level processes and energy storage operation diagrams, simulates the water level process and extracts the water level control node patterns in different time periods.

[0005] Preferably, the sub-step of S1 is: S11, the guaranteed power generation of the cascade reservoirs is calculated in reverse time sequence on a ten-day basis using the typical runoff process of the cascade reservoirs; S12, calculate the energy storage value of the cascade reservoirs at the end of each time period and draw the energy storage dispatch line; S13, repeatedly draw multiple energy storage dispatch lines, and take their upper and lower envelope lines as the upper and lower dispatch lines for cascade reservoir energy storage; S14, the corresponding runoff process is obtained based on the upper and lower dispatch lines; S15, calculate the power generation of the cascade reservoirs when increasing / decreasing output in reverse time sequence for each ten-day period; S16, the line connecting the energy storage values ​​at the end of each time period is the line for increasing or decreasing power output.

[0006] Preferably, the formula for calculating the energy storage value of cascade reservoirs is as follows: ; In the formula, For the first The reservoir is The water level at that moment was The single-cell energy storage value at that time, The number of reservoirs, The upstream reservoirs are numbered sequentially from top to bottom. The calculation formula is as follows: ; In the formula, For reservoir unit conversion factors, Let be the head of the i-th reservoir at time t. Let be the water volume of the upstream reservoir at time t.

[0007] Preferably, the sub-step of S2 is as follows: S21, based on the annual ten-day scheduling process of the cascade reservoirs in a long historical sequence, simulates and calculates the water level process; S22, based on the simulated water level process, statistically analyzes the upper limit, lower limit and average value of each ten-day period within the year.

[0008] Preferably, sub-step S3: S31: Collect historical measured water level data for each reservoir in the cascade reservoirs, ensuring that the data time span is consistent with the long historical series in S2, and includes measured records for each ten-day period; S32 divides the collected historical measured water level data into ten-day periods and calculates the upper limit and average water level for each ten-day period within the year.

[0009] Preferably, step S4 specifically includes the following steps: S41, calculate the average of the historical water level and the simulated water level on the energy storage dispatch map for each ten-day period of the year. Take the smaller of the upper limit of the historical water level and the larger of the lower limit of the energy storage dispatch map water level, and calculate the water level at the endpoint of the water level control node interval based on the interval span. S42. During the flood season, the water level control nodes of the cascade reservoirs strictly follow the scheduling procedures, and the water level control node intervals calculated in S41 are used to supplement the time periods not included in the scheduling procedures. During the non-flood season, the water level control node intervals calculated in S41 based on historical water levels and energy storage scheduling diagrams are used.

[0010] Preferably, the calculation formula for the water level at the endpoint of the water level control node interval based on the interval span is as follows: ; ; In the formula, and These are the water level values ​​at the left and right ends of the water level control zone, respectively. , and These are the average, upper, and lower limits of the water level calculated based on historical water levels and simulated water levels from the energy storage scheduling diagram. This refers to the span of the water level control zone.

[0011] Preferably, in S42, the water level control node intervals supplemented during the flood season must meet the continuity with the nodes of adjacent time periods in the scheduling procedure, that is, the difference between the endpoint water level of the supplemented interval and the water level of the node in the adjacent time period does not exceed a preset threshold; the water level control node intervals during the non-flood season must be updated regularly according to the latest historical data and energy storage scheduling diagram to adapt to changes in hydrological conditions.

[0012] A system for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams, employing the aforementioned method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams, includes: Cascade Reservoir Energy Storage Scheduling Diagram Drawing Module: Used to construct energy storage scheduling diagrams for cascade reservoirs; Energy storage scheduling diagram simulation water level characteristic statistics module: used to simulate the water level process of a long historical sequence based on the energy storage scheduling diagram, and calculate the water level characteristic values ​​at each time node; Historical measured water level characteristic statistics module: used to calculate the characteristic values ​​of each time point in the historical water level process; Time-segmented extraction template for water level control nodes in cascade reservoirs: This template is used to extract the patterns of water level control nodes in different time periods based on the cascade reservoir scheduling regulations, historical water level processes, and energy storage scheduling diagrams to simulate water level processes.

[0013] A computer device, comprising: One or more processors, said processors including one or more executable programs; When the one or more executable programs are executed by one or more processors, they are used to implement the method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams.

[0014] The present invention can achieve the following beneficial effects: This invention solves the problem of insufficient applicability of existing methods that rely on only a single basis by integrating energy storage scheduling diagrams, historical water level processes and scheduling procedures, making the extracted water level control nodes more in line with the actual needs of joint scheduling of cascade reservoirs.

[0015] This invention adopts a time-segmented extraction strategy. During the flood season, the scheduling procedure is used as the core and missing time periods are supplemented. During the non-flood season, the node interval is determined by combining simulation and historical data. This not only meets the differences in scheduling objectives in different time periods, but also refines the control granularity and improves scheduling accuracy.

[0016] This invention optimizes the scheduling time of cascade reservoirs by rationally controlling the water level control node range. This helps to better coordinate multiple objectives such as power generation and flood control while ensuring scheduling safety, thereby improving the overall efficiency of cascade reservoir operation.

[0017] This invention combines the energy storage characteristics reflected in the energy storage scheduling diagram with the actual scheduling experience of historical data, so that the extracted node patterns can not only adapt to changes in hydrological conditions and power output demand, but also provide a clear and operable control basis for actual scheduling operations. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 A flowchart for extracting the patterns of water level control nodes in cascade reservoirs.

[0019] Figure 2 This is a diagram showing the results of water level control nodes in a cascade reservoir system.

[0020] Figure 3 This is a diagram illustrating the process of discharging water during the cascade reservoir operation.

[0021] Figure 4 This is a diagram illustrating the process of power generation from cascade reservoirs. Detailed Implementation

[0022] Preferred solutions include Figures 1 to 4 As shown, a method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams includes the following steps: S1, Construct the energy storage scheduling diagram for cascade reservoir operation; S2, based on the energy storage scheduling diagram, simulates the water level process of a long historical sequence and calculates the water level characteristic values ​​at each time node; S3, calculate the characteristic values ​​of each time point in the historical water level process; S4, based on the cascade reservoir operation regulations, historical water level processes and energy storage operation diagrams, simulates the water level process and extracts the water level control node patterns in different time periods. In this embodiment, the construction of the energy storage scheduling diagram for cascade reservoir scheduling in S1 above includes the following steps: S11, the power generation of the cascade reservoirs is calculated in reverse chronological order on a ten-day basis using the typical runoff process of the cascade reservoirs: S12, calculate the energy storage value of the cascade reservoirs at the end of each time period, and draw the energy storage dispatch line: The formula for calculating the energy storage capacity of a cascade reservoir is as follows:

[0023] In the formula, For the first The reservoir is The water level at that moment was The single-cell energy storage value at that time, The number of reservoirs, The upstream reservoirs are numbered sequentially from top to bottom. The calculation formula is as follows:

[0024] In the formula, For reservoir unit conversion factors, Let be the head of the i-th reservoir at time t. Let be the water volume of the upstream reservoir at time t.

[0025] S13, repeatedly draw multiple energy storage dispatch lines, and take their upper and lower envelope lines as the upper and lower dispatch lines for cascade reservoir energy storage; S14, the corresponding runoff process is obtained based on the upper and lower dispatch lines; S15, calculate the power generation of cascade reservoirs by increasing / decreasing output in reverse chronological order for each ten-day period; S16, the line connecting the energy storage values ​​at the end of each time period is the line for increasing or decreasing power output.

[0026] In this embodiment, S2 includes the following steps: S21, based on the annual ten-day scheduling process of the cascade reservoirs in a long historical sequence, simulates and calculates the water level process; S22, based on the simulated water level process, statistically analyzes the upper limit, lower limit and average value of each ten-day period within the year.

[0027] In this embodiment, S3 includes the following steps: S32 is based on the upper limit, lower limit and average of each ten-day period of the year, calculated according to historical measured water level processes.

[0028] In this embodiment, S4 includes the following steps: S41, calculate the average of the historical water level and the simulated water level in the energy storage dispatch map for each ten-day period of the year. Take the smaller of the upper limit of the historical water level and the larger of the lower limit of the energy storage dispatch map water level. Calculate the water level at the endpoint of the water level control node interval based on the interval span. The calculation formula is as follows:

[0029]

[0030] In the formula, and These are the water level values ​​at the left and right ends of the water level control zone, respectively. , and These are the average, upper, and lower limits of the water level calculated based on historical water levels and simulated water levels from the energy storage scheduling diagram. This refers to the span of the water level control zone.

[0031] S42. During the flood season, the water level control nodes of the cascade reservoirs strictly follow the scheduling procedures, and the water level control node intervals calculated in S41 are used to supplement the time periods not included in the scheduling procedures. During the non-flood season, the water level control node intervals calculated in S41 based on historical water levels and energy storage scheduling diagrams are used.

[0032] The following section uses the cascade reservoirs of Wudongde, Baihetan, Xiluodu, Xiangjiaba, Three Gorges, and Gezhouba in the lower reaches of the Jinsha River in the Yangtze River Basin as examples to further illustrate the method of the present invention. To demonstrate the superiority of the proposed cascade reservoir scheduling method, a conventional water level node extraction method is selected as a comparative method in the embodiments. The conventional scheduling method adopts a control strategy that combines historical water levels with scheduling procedures. The water level control nodes of the six cascade reservoirs in the lower reaches of the Jinsha River are extracted using both the conventional method and the proposed method. Based on these water level control nodes, annual scheduling plans for the six cascade reservoirs from June to May are formulated. The implementation process and effects of the invention are described through the evaluation of the scheduling plan.

[0033] The upstream and inter-reservoir inflow scenarios for the cascade reservoirs were obtained from the average data of June to May for three typical years from 1959 to 2020 for the downstream cascade reservoirs of the Jinsha River. The data for high-water years, normal-water years, and low-water years were obtained at frequencies of 25%, 50%, and 75%, respectively. Cascade reservoir operation experiments were conducted under the three typical flood season inflow scenarios. The DE algorithm population size was 100, the coefficient of variation F=0.4, the crossover coefficient CR=0.3, the number of iterations was 1000 generations, and L was set to 6. The results after implementing the technical scheme are shown in Table 1. Figure 1 , Figure 2 and Figure 3 .

[0034] Depend on Figure 2 It can be seen that under the three typical annual water discharge scenarios, the amount of water discharged from the downstream cascade reservoirs of the Jinsha River is similar for both methods. According to Table 1, the amount of water discharged from the downstream cascade reservoirs of the Jinsha River by the proposed scheduling method is relatively lower than that of the conventional scheduling method, with an average difference of 140 million m³.

[0035] Figure 3 The results show that, under the three typical annual water flow scenarios, the proposed scheduling method generates higher power generation in the downstream cascade reservoirs of the Jinsha River than the conventional scheduling method for most periods. As illustrated in Table 1, the total power generation of the proposed scheduling method is higher than that of the conventional scheduling method, with an average increase of 2%.

[0036] Compared with conventional scheduling methods, the proposed scheduling method fully leverages the advantages of comprehensive water level node extraction, which not only reduces the amount of water wasted from cascade reservoirs but also increases power generation, effectively improving the overall benefits of cascade reservoir scheduling and providing a guarantee for reservoir control.

[0037] Table 1. Statistical Results of Cascade Reservoir Dispatch on the Jinsha River

[0038] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams, characterized in that... Includes the following steps: S1, Construct the energy storage scheduling diagram for cascade reservoir operation; S2, based on the energy storage scheduling diagram, simulates the water level process of a long historical sequence and calculates the water level characteristic values ​​at each time node; S3, calculate the characteristic values ​​of each time point in the historical water level process; S4, based on the cascade reservoir operation regulations, historical water level processes and energy storage operation diagrams, simulates the water level process and extracts the water level control node patterns in different time periods.

2. The method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams according to claim 1, characterized in that: The sub-steps of S1 are: S11, the guaranteed power generation of the cascade reservoirs is calculated in reverse time sequence on a ten-day basis using the typical runoff process of the cascade reservoirs; S12, calculate the energy storage value of the cascade reservoirs at the end of each time period and draw the energy storage dispatch line; S13, repeatedly draw multiple energy storage dispatch lines, and take their upper and lower envelope lines as the upper and lower dispatch lines for cascade reservoir energy storage; S14, the corresponding runoff process is obtained based on the upper and lower dispatch lines; S15, calculate the power generation of the cascade reservoirs when increasing / decreasing output in reverse time sequence for each ten-day period; S16, the line connecting the energy storage values ​​at the end of each time period is the line for increasing or decreasing power output.

3. The method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams according to claim 2, characterized in that: The formula for calculating the energy storage capacity of a cascade reservoir is as follows: ； In the formula, For the first The reservoir is The water level at that moment was The single-cell energy storage value at that time, For the number of reservoirs, The upstream reservoirs are numbered sequentially from top to bottom. The calculation formula is as follows: ； In the formula, For reservoir unit conversion factors, Let be the head of the i-th reservoir at time t. Let be the water volume of the upstream reservoir at time t.

4. The method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams according to claim 1, characterized in that: The sub-steps of S2 are: S21, based on the annual ten-day scheduling process of the cascade reservoirs in a long historical sequence, simulates and calculates the water level process; S22, based on the simulated water level process, statistically analyzes the upper limit, lower limit and average value of each ten-day period within the year.

5. The method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams according to claim 1, characterized in that: S3 sub-step: S31: Collect historical measured water level data for each reservoir in the cascade reservoirs, ensuring that the data time span is consistent with the long historical series in S2, and includes measured records for each ten-day period; S32 divides the collected historical measured water level data into ten-day periods and calculates the upper limit and average water level for each ten-day period within the year.

6. The method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams according to claim 1, characterized in that: S4 specifically includes the following steps. S41, calculate the average of the historical water level and the simulated water level on the energy storage dispatch map for each ten-day period of the year. Take the smaller of the upper limit of the historical water level and the larger of the lower limit of the energy storage dispatch map water level, and calculate the water level at the endpoint of the water level control node interval based on the interval span. S42. During the flood season, the water level control nodes of the cascade reservoirs strictly follow the scheduling procedures, and the water level control node intervals calculated in S41 are used to supplement the time periods not included in the scheduling procedures. During the non-flood season, the water level control node intervals calculated in S41 based on historical water levels and energy storage scheduling diagrams are used.

7. The method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams according to claim 1, characterized in that: The formula for calculating the water level at the endpoint of the water level control node based on the interval span is as follows: ； ； In the formula, and These are the water level values ​​at the left and right ends of the water level control zone, respectively. , and These are the average, upper, and lower limits of the water level calculated based on historical water levels and simulated water levels from the energy storage scheduling diagram. This refers to the span of the water level control zone.

8. The method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams according to claim 1, characterized in that: In S42, the water level control node intervals supplemented during the flood season must meet the continuity with the nodes of adjacent time periods in the dispatching procedure, that is, the difference between the endpoint water level of the supplemented interval and the water level of the node in the adjacent time period does not exceed the preset threshold; the water level control node intervals during the non-flood season must be updated regularly according to the latest historical data and energy storage dispatching diagram to adapt to changes in hydrological conditions.

9. A system for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams, characterized in that: The system employs a method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams, as described in any one of claims 1-8. The system comprises: Cascade Reservoir Energy Storage Scheduling Diagram Drawing Module: Used to construct energy storage scheduling diagrams for cascade reservoirs; Energy storage scheduling diagram simulation water level characteristic statistics module: used to simulate the water level process of a long historical sequence based on the energy storage scheduling diagram, and calculate the water level characteristic values ​​at each time node; Historical measured water level characteristic statistics module: used to calculate the characteristic values ​​of each time point in the historical water level process; Time-segmented extraction template for water level control nodes in cascade reservoirs: This template is used to extract the patterns of water level control nodes in different time periods based on the cascade reservoir scheduling regulations, historical water level processes, and energy storage scheduling diagrams to simulate water level processes.

10. A computer device, comprising: One or more processors, said processors including one or more executable programs; When the one or more executable programs are executed by one or more processors, they are used to implement the method for extracting water level control nodes of cascade reservoirs based on energy storage scheduling diagrams according to any one of claims 1-8.

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