A combined dispatching optimization method, system, terminal and medium for cascade hydropower stations

Abstract

The present invention discloses a method, system, terminal and medium for optimizing the combined dispatching of cascade hydropower stations, relating to the technical field of power dispatching. The key points of its technical solution are as follows: initiate a dispatching once when the total cumulative value of the output fluctuations of all power stations reaches the fluctuation threshold; select the power stations whose output fluctuation directions are consistent with the deviation directions between the actual output and the planned output of the cascade hydropower stations as the target power stations; select the target power station corresponding to the maximum cumulative value of the output fluctuations as the dispatching power station; take reducing the output fluctuations of the dispatching power station and narrowing the deviation between the actual output and the planned output of the cascade hydropower stations as the dispatching target, and establish a dispatching function in combination with the basic constraints for each level of power stations to participate in the dispatching. The present invention can reduce the output fluctuations from both the global perspective of the cascade hydropower stations and the local perspective of individual hydropower stations, and can respond more promptly to the random fluctuations of the predicted load, effectively improving the stability and reliability of the combined dispatching of cascade hydropower stations.

Description

Technical Field

[0001] The present invention relates to the technical field of power dispatching, and more specifically, to a cascade hydropower station joint dispatching optimization method, system, terminal and medium. Background Art

[0002] The joint dispatching of cascade hydropower stations refers to the unified coordinated dispatching of a group of interconnected cascade reservoirs, hydropower stations and related engineering facilities within a river basin. Through optimized dispatching, the functions and benefits of each reservoir and hydropower station are maximized. The main dispatching objectives include, but are not limited to, reducing water abandonment, increasing the operating head, and smoothing the output fluctuations, etc. Among them, the impact of output fluctuations on the power grid is multi-faceted, involving multiple aspects such as the stability of the power grid, power quality, planning, operation dispatching, economy, and market. Therefore, the research on output fluctuations in cascade hydropower stations is very important for the safe and stable operation of the power grid.

[0003] Currently, considering the power loss problem in long-distance power transmission, each level of hydropower station in the cascade hydropower station generally supplies power to the nearby area, and then distributes the actual output of each hydropower station with the minimum output fluctuation between the actual output and the predicted load of each hydropower station. However, the output of the cascade hydropower station is jointly affected by the random fluctuations of the inflow of each hydropower station and the corresponding predicted load. In the short-term time scale, the actual output of each hydropower station is generally adjusted according to the fluctuation of the predicted load, which is likely to result in the mismatch between the overall output and the overall inflow of the cascade hydropower station in the medium- and long-term time scale, leading to the remaining flow of some hydropower stations being unable to meet the basic water use requirements; in addition, the actual outputs of each hydropower station are not strongly correlated, and when the overall output of the cascade hydropower station matches the overall load, the outputs of multiple hydropower stations are still frequently adjusted; moreover, when the short-term time scales of each hydropower station are kept consistent, the timeliness and effect of reducing the output fluctuations of the entire cascade hydropower station are poor.

[0004] Therefore, how to research and design a cascade hydropower station joint dispatching optimization method, system, terminal and medium that can overcome the above defects is an urgent problem for us to solve at present. Summary of the Invention

[0005] To solve the deficiencies in the prior art, the purpose of the present invention is to provide a cascade hydropower station joint dispatching optimization method, system, terminal and medium, which can flexibly select hydropower stations for output dispatching in the dynamically changing short-term time scale while making the cascade hydropower station gradually tend to stable output in the medium- and long-term time scale, and can reduce the output fluctuations from both the global perspective of the cascade hydropower station and the local perspective of a single hydropower station, and is more responsive to the random fluctuations of the predicted load, effectively improving the stability and reliability of the cascade hydropower station joint dispatching.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] In a first aspect, a combined dispatching optimization method for cascade hydropower stations is provided, including the following steps:

[0008] Determine the planned output of the cascade hydropower stations on a medium- and long-term time scale;

[0009] Analyze the output fluctuations of each hydropower station in the cascade hydropower stations, and initiate a dispatching once when the total cumulative value of the output fluctuations of all hydropower stations reaches the fluctuation threshold;

[0010] When the dispatching is initiated, select the hydropower stations whose output fluctuation directions are consistent with the deviation direction between the actual output and the planned output of the cascade hydropower stations as the target hydropower stations;

[0011] Select the target hydropower station corresponding to the maximum cumulative value of the output fluctuations as the dispatching hydropower station for a single dispatching;

[0012] Take reducing the output fluctuations of the dispatching hydropower station and narrowing the deviation between the actual output and the planned output of the cascade hydropower stations as the dispatching objectives, and establish a dispatching function in combination with the basic constraint conditions for each hydropower station to participate in the dispatching;

[0013] Solve the actual output of the dispatching hydropower station on a short-term time scale after a single dispatching through the objective function.

[0014] Further, the process of determining the planned output of the cascade hydropower stations on a medium- and long-term time scale is specifically as follows:

[0015] Determine the initial water levels and steady-state water levels of each hydropower station in the cascade hydropower stations. The steady-state water levels are divided into the first water level to meet the water use demand during the dry season and the second water level to meet the flood control demand during the flood season;

[0016] Estimate the inflow of non-power station inflow in the confluence areas corresponding to each hydropower station on a medium- and long-term time scale;

[0017] Determine the power generation coefficient of each hydropower station according to the power generation parameters of each hydropower station and the upstream and downstream relationships of each hydropower station. The power generation parameters represent the power generation that can be converted by unit flow;

[0018] Solve the planned output of the cascade hydropower stations on a medium- and long-term time scale with the goal that the final water levels of each hydropower station reach the steady-state water levels.

[0019] Further, the specific expression for solving the planned output of the cascade hydropower stations on a medium- and long-term time scale is:

[0020] ;

[0021] Among them, Indicates the planned output of cascade hydropower stations on a medium- and long-term time scale. The cascade hydropower stations include n power stations; Indicates the medium- and long-term time scale; Indicates the inflow reservoir inflow between non-power stations in the confluence area corresponding to the i-th power station within the medium- and long-term time scale; Indicates the initial water level of the i-th power station; Indicates the steady-state water level of the i-th power station; Indicates the reservoir area corresponding to the i-th power station; Indicates the power generation parameters of the j-th power station.

[0022] Furthermore, the calculation process of the total cumulative value of the output fluctuations of all power stations is specifically as follows:

[0023] Integrate and sum the output fluctuations of a single power station to obtain the cumulative value of the output fluctuations of a single power station. The output fluctuation is the absolute value or square of the difference between the actual output of the power station and the predicted load of the corresponding power supply area;

[0024] Calculate the total cumulative value of the output fluctuations of all power stations by summing the cumulative values of the output fluctuations of each power station.

[0025] Furthermore, the expression for initiating a dispatch once when the total cumulative value of the output fluctuations of all power stations reaches the fluctuation threshold is:

[0026] ;

[0027] Among them, n represents the number of power stations in the cascade hydropower station; Indicates the starting time of the cumulative output fluctuation; Indicates the cumulative duration of the cumulative output fluctuation; Indicates the actual output of the i-th power station at time t; Indicates the predicted load of the power supply area corresponding to the i-th power station at time t; Indicates the fluctuation threshold.

[0028] Furthermore, if the difference between the actual output of the power station and the predicted load of the corresponding power supply area is positive, the output fluctuation direction of the corresponding power station is the positive direction; if the difference between the actual output of the power station and the predicted load of the corresponding power supply area is negative, the output fluctuation direction of the corresponding power station is the negative direction;

[0029] And, if the difference between the actual output of the cascade hydropower station and the planned output is positive, the deviation direction between the actual output and the planned output of the cascade hydropower station is the positive direction; if the difference between the actual output of the cascade hydropower station and the planned output is negative, the deviation direction between the actual output and the planned output of the cascade hydropower station is the negative direction.

[0030] Further, the expression of the scheduling function is specifically as follows:

[0031] ;

[0032] where, represents the actual output of the scheduling power station D during the (q + 1)-th scheduling process of the cascade hydropower station; represents the planned output of the cascade hydropower station on the medium- and long-term time scale, and the cascade hydropower station includes n-level power stations; represents the medium- and long-term time scale; represents the number of times the i-th level power station starts scheduling; represents the actual output of the i-th level power station during the k-th start scheduling; represents the short-term time scale of the i-th level power station during the k-th start scheduling; represents the lower limit of the output of the i-th level power station; represents the actual output of the i-th level power station; represents the upper limit of the output of the i-th level power station; represents the lower limit of the water level of the i-th level power station; represents the actual water level of the i-th level power station; represents the upper limit of the water level of the i-th level power station; represents the cumulative value of the output fluctuation corresponding to the cumulative duration during the q-th scheduling process of the scheduling power station D in the cascade hydropower station; represents the cumulative value of the output fluctuation corresponding to the cumulative duration during the (q + 1)-th scheduling process of the scheduling power station D in the cascade hydropower station; represents the second largest cumulative value of the output fluctuation corresponding to the cumulative duration during the q-th scheduling process of all target power stations in the cascade hydropower station; represents the short-term time scale of the q-th scheduling of the cascade hydropower station; represents the total output of the cascade hydropower station after the q-th scheduling is completed; represents the short-term time scale of the (q + 1)-th scheduling of the cascade hydropower station; represents the total output of the cascade hydropower station after the (q + 1)-th scheduling is completed; represents the number of times the cascade hydropower station starts scheduling within the long-term time scale.

[0033] In a second aspect, a joint scheduling optimization system for a cascade hydropower station is provided. The system is used to implement a joint scheduling optimization method for a cascade hydropower station as described in any one of the first aspects, and includes:

[0034] An output analysis module, configured to determine the planned output of the cascade hydropower station on the medium- and long-term time scale;

[0035] The startup monitoring module is used to analyze the output power fluctuations of each power station in a cascade hydropower station, and initiate a dispatch once when the total cumulative value of the output power fluctuations of all power stations reaches the fluctuation threshold;

[0036] The target screening module is used to select, when the dispatch is initiated, the power stations whose output power fluctuation directions are consistent with the deviation directions between the actual output power and the planned output power of the cascade hydropower station as target power stations;

[0037] The dispatch selection module is used to select the target power station corresponding to the maximum cumulative value of output power fluctuations as the dispatch power station for a single dispatch;

[0038] The function construction module is used to take reducing the output power fluctuations of the dispatch power station and narrowing the deviation between the actual output power and the planned output power of the cascade hydropower station as dispatch objectives, and establish a dispatch function in combination with the basic constraint conditions for each power station to participate in the dispatch;

[0039] The output power optimization module is used to solve the actual output power of the dispatch power station on a short-term time scale after a single dispatch through the objective function.

[0040] In a third aspect, a computer terminal is provided, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements a combined dispatch optimization method for a cascade hydropower station as described in any one of the first aspects.

[0041] In a fourth aspect, a computer-readable medium is provided, on which a computer program is stored. When the computer program is executed by a processor, it can implement a combined dispatch optimization method for a cascade hydropower station as described in any one of the first aspects.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. The combined dispatch optimization method for a cascade hydropower station provided by the present invention can flexibly select hydropower stations for output power dispatch on a dynamically changing short-term time scale while making the output power of the cascade hydropower station gradually tend to be stable on a medium- and long-term time scale. It can reduce output power fluctuations from both the global perspective of the cascade hydropower station and the local perspective of a single hydropower station, and respond more promptly to the random fluctuations of the predicted load, effectively improving the stability and reliability of the combined dispatch of the cascade hydropower station;

[0044] 2. When determining the planned output power of the cascade hydropower station on a medium- and long-term time scale, the present invention comprehensively considers the initial water levels and basic flow requirements of each power station, and can automatically balance the risk resistance performance of the cascade hydropower station on each medium- and long-term time scale;

[0045] 3. The present invention first independently calculates the cumulative value of the output fluctuations of a single power station, and then calculates the total cumulative value of the output fluctuations of all power stations based on the sum of the cumulative values of the output fluctuations of each power station, which can automatically identify the incremental phenomenon of long-distance power transmission under the condition of supply-demand balance of cascade hydropower stations;

[0046] 4. When the present invention performs joint dispatching, taking the output fluctuation of a single hydropower station as the direct optimization target, and then iteratively optimizing the output fluctuations of each hydropower station to achieve the overall output optimization of the cascade hydropower stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not constitute a limitation to the embodiments of the present invention. In the drawings:

[0048] Figure 1 is the flowchart in Embodiment 1 of the present invention;

[0049] Figure 2 is the system block diagram in Embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the embodiments and the drawings. The illustrative embodiments and descriptions thereof of the present invention are only used to explain the present invention and do not constitute a limitation to the present invention.

[0051] Embodiment 1: A method for optimizing the joint dispatching of cascade hydropower stations, as Figure 1 shown, includes the following steps:

[0052] S1: Determine the planned output of the cascade hydropower stations on a medium- and long-term time scale;

[0053] S2: Analyze the output fluctuations of each power station in the cascade hydropower stations, and initiate a dispatching when the total cumulative value of the output fluctuations of all power stations reaches the fluctuation threshold;

[0054] S3: When the dispatching is initiated, select the power stations whose output fluctuation directions are consistent with the deviation direction between the actual output and the planned output of the cascade hydropower stations as the target power stations;

[0055] S4: Select the target power station corresponding to the maximum cumulative value of the output fluctuations as the dispatching power station for a single dispatching;

[0056] S5: Take reducing the output fluctuations of the dispatching power station and narrowing the deviation between the actual output and the planned output of the cascade hydropower stations as the dispatching objectives, and establish a dispatching function in combination with the basic constraints for each power station to participate in the dispatching;

[0057] S6: Solve for the actual output of the scheduling power station after a single scheduling on a short - term time scale through the objective function.

[0058] In step S1, the planned output of cascade hydropower stations on a medium - and long - term time scale can be solved using traditional models. For example, it can be solved with the minimum fluctuation between the overall output of cascade hydropower stations and the overall predicted load.

[0059] In addition, the planned output of cascade hydropower stations on a medium - and long - term time scale can also be solved by comprehensively considering the initial water levels and basic flow requirements of each power station.

[0060] Specifically, the process of determining the planned output of cascade hydropower stations on a medium - and long - term time scale is as follows: Determine the initial water levels and steady - state water levels of each power station in the cascade hydropower stations. The steady - state water levels are divided into the first water level to meet water use requirements during the dry season and the second water level to meet flood control requirements during the flood season; Estimate the non - power - station - to - reservoir inflow in the medium - and long - term time scale for the catchment area corresponding to each power station; Determine the power generation coefficient of each power station according to the power generation parameters of each power station and the upstream - downstream relationship of each power station. The power generation parameters represent the electric energy that can be converted per unit flow; Solve for the planned output of cascade hydropower stations on a medium - and long - term time scale with the goal that the final water level of each power station reaches the steady - state water level.

[0061] It should be noted that the specific values of the steady - state water levels can be flexibly selected according to different seasons. The non - power - station - to - reservoir inflow refers to the flow that does not include the flow that flows into the next hydropower station after the upper - level hydropower station generates electricity.

[0062] For example, the specific expression for solving the planned output of cascade hydropower stations on a medium - and long - term time scale is as follows:

[0063] ;

[0064] Among them, represents the planned output of cascade hydropower stations on a medium - and long - term time scale, and the cascade hydropower stations include n levels of power stations; represents the medium - and long - term time scale; represents the non - power - station - to - reservoir inflow in the medium - and long - term time scale for the catchment area corresponding to the i - th power station; represents the initial water level of the i - th power station; represents the steady - state water level of the i - th power station; represents the reservoir area corresponding to the i - th power station; represents the power generation parameter of the j - th power station.

[0065] In step S2, the specific calculation process of the total cumulative value of the output power fluctuations of all power stations is as follows: the cumulative value of the output power fluctuations of a single power station is obtained by integrating and summing the output power fluctuations of the single power station, where the output power fluctuation is the absolute value or square of the difference between the actual output power of the power station and the predicted load of the corresponding power supply area; the total cumulative value of the output power fluctuations of all power stations is calculated by summing the cumulative values of the output power fluctuations of each power station.

[0066] For example, the expression for initiating a dispatch once when the total cumulative value of the output power fluctuations of all power stations reaches the fluctuation threshold is:

[0067] ;

[0068] where n represents the number of power stations in the cascade hydropower station; represents the starting time of the cumulative output power fluctuation; represents the cumulative duration of the cumulative output power fluctuation; represents the actual output power of the i-th power station at time t; represents the predicted load of the power supply area corresponding to the i-th power station at time t; represents the fluctuation threshold.

[0069] In step S3, if the difference between the actual output power of the power station and the predicted load of the corresponding power supply area is positive, the output power fluctuation direction of the corresponding power station is the positive direction; if the difference between the actual output power of the power station and the predicted load of the corresponding power supply area is negative, the output power fluctuation direction of the corresponding power station is the negative direction.

[0070] If the difference between the actual output power and the planned output power of the cascade hydropower station is positive, the deviation direction between the actual output power and the planned output power of the cascade hydropower station is the positive direction; if the difference between the actual output power and the planned output power of the cascade hydropower station is negative, the deviation direction between the actual output power and the planned output power of the cascade hydropower station is the negative direction.

[0071] It should be noted that only when both the output power fluctuation direction and the deviation direction are the negative direction or both are the positive direction, can the corresponding hydropower station be regarded as the target power station.

[0072] In step S4, assuming there are three hydropower stations A, B, and C, and the cumulative values of the output power fluctuations of the three power stations A, B, and C within a certain period of time are respectively , , , using a unified basic unit quantity, the output power fluctuation directions of the three power stations A, B, and C are the negative direction, the positive direction, and the negative direction respectively.

[0073] If the difference between the actual output of the cascade hydropower station at this time (the sum of the outputs from the start time to the current time corresponding to the medium- and long-term time scale) and the planned output (the sum of the outputs from the start time to the current time corresponding to the medium- and long-term time scale) is positive, it indicates that the output is relatively large and the deviation direction is the positive direction. At this time, only power station B meets the requirements and is regarded as the dispatching power station for dispatching. The output of power station B can be reduced so that the cumulative value of output fluctuations can be adjusted from 4 to 3 within an equal time period.

[0074] If the difference between the actual output of the cascade hydropower station at this time (the sum of the outputs from the start time to the current time corresponding to the medium- and long-term time scale) and the planned output (the sum of the outputs from the start time to the current time corresponding to the medium- and long-term time scale) is negative, it indicates that the output is relatively small and the deviation direction is the negative direction. At this time, power stations A and C meet the requirements. Both power stations A and C are regarded as target power stations. However, since the cumulative value of output fluctuations of power station A is relatively large, power station A is regarded as the dispatching power station for dispatching. The output of power station B can be increased so that the cumulative value of output fluctuations can be adjusted from to not exceed .

[0075] In step S5, the specific expression of the dispatching function is:

[0076] ;

[0077] Among them, represents the actual output of the dispatching power station D during the (q + 1)-th dispatching process of the cascade hydropower station; represents the planned output of the cascade hydropower station in the medium- and long-term time scale, and the cascade hydropower station includes n-level power stations; represents the medium- and long-term time scale; represents the number of times the i-th level power station starts dispatching; represents the actual output of the i-th level power station during the k-th start dispatching; represents the short-term time scale of the i-th level power station during the k-th start dispatching; represents the lower limit of the output of the i-th level power station; represents the actual output of the i-th level power station; represents the upper limit of the output of the i-th level power station; represents the lower limit of the water level of the i-th level power station; represents the actual water level of the i-th level power station; represents the upper limit of the water level of the i-th level power station; represents the cumulative value of output fluctuations corresponding to the cumulative duration during the q-th dispatching process of the dispatching power station D in the cascade hydropower station; represents the cumulative duration The corresponding cumulative value of output fluctuation; Indicates the cumulative duration during the q-th scheduling process of the cascade hydropower station for all target power stations The second largest corresponding cumulative value of output fluctuation; Indicates the short-term time scale of the q-th scheduling of the cascade hydropower station; Indicates the total output of the cascade hydropower station after the q-th scheduling is completed; Indicates the short-term time scale of the (q + 1)-th scheduling of the cascade hydropower station; Indicates the total output of the cascade hydropower station after the (q + 1)-th scheduling is completed; Indicates the number of times the cascade hydropower station starts scheduling within the long-term time scale.

[0078] Embodiment 2: A combined scheduling optimization system for a cascade hydropower station, which is used to implement a combined scheduling optimization method for a cascade hydropower station described in Embodiment 1, as Figure 2 shown, including an output analysis module, a startup monitoring module, a target screening module, a scheduling selection module, a function construction module, and an output optimization module.

[0079] Among them, the output analysis module is used to determine the planned output of the cascade hydropower station on the medium- and long-term time scale; the startup monitoring module is used to analyze the output fluctuations of each level of the cascade hydropower station and initiate a scheduling once when the total cumulative value of the output fluctuations of all power stations reaches the fluctuation threshold; the target screening module is used to select, when the scheduling is started, at least one power station whose output fluctuation direction is consistent with the deviation direction between the actual output and the planned output of the cascade hydropower station as the target power station; the scheduling selection module is used to select the target power station corresponding to the largest cumulative value of output fluctuation as the scheduling power station for a single scheduling; the function construction module is used to take reducing the output fluctuation of the scheduling power station and narrowing the deviation between the actual output and the planned output of the cascade hydropower station as the scheduling goal, and establish a scheduling function in combination with the basic constraint conditions for each level of power station to participate in the scheduling; the output optimization module is used to solve the actual output of the scheduling power station on the short-term time scale after a single scheduling through the objective function.

[0080] The present invention also describes a computer terminal, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements a combined scheduling optimization method for a cascade hydropower station described in Embodiment 1.

[0081] The present invention also describes a computer-readable medium, on which a computer program is stored. When the computer program is executed by the processor, it can implement a combined scheduling optimization method for a cascade hydropower station described in Embodiment 1.

[0082] Working principle: When the present invention enables the cascade hydropower stations to gradually tend to stable power output on a medium- and long-term time scale, it flexibly selects hydropower stations for power output scheduling on a dynamically changing short-term time scale. It can reduce the power output fluctuations from both the global perspective of the cascade hydropower stations and the local perspective of individual hydropower stations, and responds more promptly to the random fluctuations of the predicted load, effectively improving the stability and reliability of the combined dispatching of cascade hydropower stations.

[0083] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0084] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of processes and / or blocks in the flowchart and / or block diagram can also be implemented. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0085] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means implements the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0086] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0087] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for joint dispatching optimization of cascade hydropower stations, characterized in that: The following steps are involved: Determine the planned output of cascade hydropower stations in the medium and long term; Analyze the output fluctuations of each level of the cascade hydropower station, and initiate a dispatch when the total cumulative value of the output fluctuations of all stations reaches the fluctuation threshold; When the dispatch is started, a power station whose output fluctuation direction is consistent with the deviation direction between the actual output and the planned output of the cascade hydropower station is selected as the target power station; The target power station corresponding to the maximum cumulative value of output fluctuation is selected as the dispatching power station for single dispatch; The dispatching goal is to reduce the output fluctuation of the dispatching power station and reduce the deviation between the actual output and the planned output of the cascade hydropower station, and establish a dispatching function in combination with the basic constraints of the dispatching of power stations at all levels; The actual output of the dispatching power station in the short term after a single dispatch is solved through the dispatching function; The process of determining the planned output of the cascade hydropower stations in the medium and long term is as follows: Determine the initial water level and steady-state water level of each power station in the cascade hydropower station. The steady-state water level is divided into the first water level that meets the water demand in the dry season and the second water level that meets the flood control demand in the flood season; Estimate the inflow of non-power station areas into the catchment areas corresponding to each level of power stations in the medium and long term; The power generation coefficient of each power station is determined according to the power generation parameters of each power station and the upstream and downstream relationship of each power station. The power generation parameters represent the power generation that can be converted into unit flow; With the goal of reaching the steady-state water level for each power station, the planned output of the cascade hydropower stations in the medium and long term is solved.

2. A cascade hydropower station joint dispatch optimization method according to claim 1, characterized in that: The specific expression for solving the planned output of the cascade hydropower station in the medium and long term time scale is: ； in, It represents the planned output of cascade hydropower stations in the medium and long term. The cascade hydropower station includes n-level power stations. Indicates medium to long term time scale; It represents the inflow of non-power stations into the catchment area corresponding to the i-th power station in the medium and long term time scale; represents the initial water level of the i-th power station; represents the steady-state water level of the ith power station; represents the reservoir area corresponding to the i-th level power station; Represents the power generation parameters of the j-th power station.

3. The method for joint dispatching and optimizing cascade hydropower stations according to claim 1 is characterized in that: The calculation process of the total cumulative value of the output fluctuations of all power stations is specifically as follows: The output fluctuation of a single power station is integrated and summed to obtain the cumulative value of the output fluctuation of a single power station. The output fluctuation is the absolute value or square of the difference between the actual output of the power station and the predicted load of the corresponding power supply area. The total cumulative value of the output fluctuations of all power stations is calculated by summing up the cumulative values ​​of the output fluctuations of each power station.

4. The method for joint dispatching optimization of cascade hydropower stations according to claim 1 is characterized in that: The expression for starting a dispatch when the total cumulative value of the output fluctuations of all power stations reaches the fluctuation threshold is: ； Where n represents the number of power stations in the cascade hydropower station; Indicates the starting time of output fluctuation accumulation; Indicates the cumulative duration of output fluctuation accumulation; represents the actual output of the i-th power station at time t; It represents the predicted load of the power supply area corresponding to the i-th power station at time t; Indicates the fluctuation threshold.

5. The method for joint dispatching optimization of cascade hydropower stations according to claim 1 is characterized in that: If the difference between the actual output of the power station and the predicted load of the corresponding power supply area is positive, the output fluctuation direction of the corresponding power station is positive; if the difference between the actual output of the power station and the predicted load of the corresponding power supply area is negative, the output fluctuation direction of the corresponding power station is negative; Also, if the difference between the actual output and the planned output of the cascade hydropower station is a positive value, then the direction of the deviation between the actual output and the planned output of the cascade hydropower station is a positive direction; if the difference between the actual output and the planned output of the cascade hydropower station is a negative value, then the direction of the deviation between the actual output and the planned output of the cascade hydropower station is a negative direction.

6. The method for joint dispatching optimization of cascade hydropower stations according to claim 1 is characterized in that: The expression of the scheduling function is specifically: ； in, represents the actual output of the dispatching power station D in the q+1th dispatching process of the cascade hydropower station; It represents the planned output of cascade hydropower stations in the medium and long term. The cascade hydropower station includes n-level power stations. Indicates medium to long term time scale; Indicates the number of times the i-th power station starts dispatching; It represents the actual output of the i-th power station at the k-th startup dispatch; represents the short-term time scale of the i-th power station when it starts dispatching at the kth time; Indicates the lower limit of the output of the i-th power station; represents the actual output of the i-th power station; represents the output upper limit of the i-th power station; represents the lower limit of the water level of the i-th power station; represents the actual water level of the i-th power station; represents the upper limit of the water level of the i-th power station; It represents the cumulative duration of the dispatching power station D during the qth dispatching process of the cascade hydropower station. The corresponding cumulative value of output fluctuation; It represents the cumulative duration of the dispatching power station D during the q+1th dispatching process of the cascade hydropower station. The corresponding cumulative value of output fluctuation; Indicates the cumulative duration of all target power stations during the qth dispatch of cascade hydropower stations The corresponding second largest output fluctuation cumulative value; represents the short-term time scale of the qth dispatch of cascade hydropower stations; It represents the total output of the cascade hydropower station after the qth dispatch is completed; represents the short-term time scale of the q+1th dispatch of the cascade hydropower stations; It represents the total output of the cascade hydropower station after the q+1th dispatch is completed; It indicates the number of times cascade hydropower stations are started and dispatched in the long term.

7. A cascade hydropower station joint dispatch optimization system, characterized in that: The system is used to implement a cascade hydropower station joint dispatch optimization method as described in any one of claims 1 to 6, comprising: Output analysis module, used to determine the planned output of cascade hydropower stations in the medium and long term; Start the monitoring module, which is used to analyze the output fluctuations of each level of the cascade hydropower station and start a dispatch when the total cumulative value of the output fluctuations of all power stations reaches the fluctuation threshold; A target screening module is used to select, when scheduling is started, a power station whose output fluctuation direction of at least one power station is consistent with the deviation direction between the actual output and the planned output of the cascade hydropower station as a target power station; A dispatch selection module is used to select the target power station corresponding to the maximum cumulative value of output fluctuation as the dispatch power station for single dispatch; Function building module, which is used to reduce the output fluctuation of the dispatching power station and reduce the deviation between the actual output and the planned output of the cascade hydropower station as the dispatching target, and establish the dispatching function in combination with the basic constraint conditions of the power stations at all levels participating in the dispatching; The output optimization module is used to solve the actual output of the dispatching power station in the short term after a single dispatch through the dispatching function.

8. A computer terminal comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, a joint dispatch optimization method for cascade hydropower stations as described in any one of claims 1 to 6 is implemented.

9. A computer readable medium having a computer program stored thereon, characterized in that: The computer program is executed by a processor to implement a method for optimizing joint dispatching of cascade hydropower stations as described in any one of claims 1 to 6.

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