Method for recommending economic operation of hydropower station based on water level iteration and load process

Abstract

The present application relates to the technical field of process control, in particular to a hydropower station economic operation recommendation method based on water level iteration and load process. The present application integrates load process generation, unit operation mode optimization and water level feedback correction into a unified closed-loop calculation process. After the initial and final water levels and the inflow boundary are given, the unit combination and time-sharing output scheme that adapt to the current operation condition are automatically formed, and the operation parameters are continuously corrected according to the regulation and storage results. Therefore, the power generation arrangement and the reservoir water level change can be coordinated with each other, the final water level at each stage can gradually meet the planned requirements, and the adaptability of the recommended scheme under different operation scenarios can be improved. Through unified checking of the final operation results and giving economic operation evaluation, the reliability, executability and decision efficiency of the monthly or stage operation mode can be improved.

Description

Technical Field

[0001] This invention relates to the field of process control technology, and in particular to a method for recommending economic operation of hydropower stations based on water level iteration and load processes. Background Technology

[0002] The field of process control technology involves the automatic detection and adjustment of variables in industrial production processes, aiming to maintain the stability and optimality of system operation. It is widely used in process industries such as power, chemical, and metallurgy. Among these, the recommended method for economic operation of hydropower stations refers to the technical means used in the joint operation of hydropower and power systems to plan and guide the overall power generation plan and unit start-up and shutdown logic of the power station, in order to coordinate the load distribution of each unit and meet the grid dispatching requirements. This is achieved by utilizing existing hydrological forecast data and equipment operating parameters.

[0003] Traditional methods for recommending economic operation of hydropower stations, while capable of generating power schedules based on inflow forecasts and equipment operating conditions, suffer from several drawbacks. These include the continuous influence between reservoir water levels, power load, and unit operating status during monthly or phased operations. A single operational plan cannot be synchronously revised with the results of water storage and regulation, easily leading to discrepancies between the end-of-phase water level and the planned target. Furthermore, the applicable operating modes vary under different operational boundaries. Without unified coordination between unit combination, load processes, and water balance, the recommended results may only be feasible in certain aspects, failing to simultaneously consider economic efficiency, operational stability, and phased scheduling objectives, thus affecting the completeness of the operational plan and its practical application effectiveness. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a recommended method for the economic operation of hydropower stations based on water level iteration and load processes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a method for recommending the economic operation of hydropower stations based on water level iteration and load processes, comprising the following steps:

[0006] Obtain the scheduling boundary parameters used by the hydropower station when carrying out reservoir regulation and unit power generation;

[0007] Based on the dispatch boundary parameters and the preset power output characteristics of the hydropower station, determine the initial power output parameters to be used when allocating power output to the hydropower station units;

[0008] Establish an objective function with the goal of minimizing water consumption, and solve the objective function with reference to the initial output parameters to determine the scheduling and operation sequence group for unit power generation, power generation water use and non-power generation discharge processes;

[0009] The reservoir regulation and storage operation is performed with reference to the scheduling operation sequence group and scheduling boundary parameters to obtain the water level regulation and storage parameters after the reservoir regulation and storage.

[0010] Determine the degree of deviation between the water level regulation parameters and the scheduling boundary parameters, readjust the initial output parameters according to the degree of deviation until the preset convergence requirements are met, and determine the corresponding convergence result group;

[0011] Perform constraint verification on the convergence result set, and recommend the operation mode based on the constraint verification results.

[0012] As a further aspect of the present invention, the scheduling boundary parameters include: the initial water level at the start of the reservoir scheduling cycle and the target final water level at the end of the scheduling cycle; the initial reservoir capacity determined according to a preset water level-reservoir capacity curve and the initial water level; the expected inflow sequence for each scheduling period, the number of scheduling periods included in the expected inflow sequence, the length of the scheduling periods, and the scheduling cycle duration calculated based on the number of scheduling periods and the length of the scheduling periods; the total outflow within the scheduling cycle determined according to the expected inflow sequence, the initial reservoir capacity, and the target reservoir capacity corresponding to the target final water level; and the average head of the hydropower station units during power generation, determined according to a preset downstream water level curve, the initial water level, and the target final water level.

[0013] As a further aspect of the present invention, the step of determining the initial output parameters used when allocating power output to hydropower station units based on scheduling boundary parameters and preset power output characteristics of the hydropower station includes:

[0014] Extract the total outflow of water within the scheduling cycle from the scheduling boundary parameters, and simultaneously obtain the historical water consumption rate statistical range representing the water consumption level corresponding to the power generation and the expected water abandonment within the scheduling cycle. Select the median value of the historical water consumption rate statistical range to obtain the initial water consumption rate. Calculate the generateable water volume based on the total outflow of water within the scheduling cycle and the expected water abandonment. Calculate the average daily power output of the hydropower station based on the generateable water volume, the initial water consumption rate, and the duration of the scheduling cycle.

[0015] The power output of hydropower stations during each scheduling period in the same historical period is obtained. Based on the power output of hydropower stations during each scheduling period in the same historical period and the average daily power output of the corresponding hydropower stations, the per-unit value of power output for each scheduling period is determined. The per-unit values ​​of power output are arranged in the order of scheduling periods to construct a typical daily power output curve. The power output characteristics currently adopted are obtained. Based on the typical daily power output curve and different power output characteristics, the initial total power output for each scheduling period is determined to form an initial total power output sequence.

[0016] The average head in the scheduling boundary parameters is set as the initial head for each scheduling period. The initial heads are arranged in the order of the scheduling periods to form an initial head sequence. The initial total output sequence and the initial head sequence are integrated as the initial output parameters.

[0017] As a further aspect of the present invention, the step of establishing an objective function with the goal of minimizing water consumption, and solving the objective function with reference to the initial output parameters to determine the scheduling and operation sequence set for unit power generation, power generation water use, and non-power generation discharge processes includes:

[0018] The system obtains the power generation flow rate corresponding to each hydropower unit under different operating heads and unit outputs, and constructs the unit water consumption curve. Based on the power generation flow rate corresponding to the unit output and operating head in the unit water consumption curve, the power generation water consumption parameters are determined. The system obtains the start-up and shutdown status of each unit within the scheduling cycle, and determines the start-up water consumption parameters and shutdown water consumption parameters based on the start-up and shutdown status of each unit. The system obtains the vibration interval representing the prohibited operating output range of the unit, and determines the vibration interval penalty water consumption parameters based on the relationship between the unit output and the vibration interval in adjacent scheduling periods. An objective function is established to minimize the sum of the power generation water consumption parameters, start-up water consumption parameters, shutdown water consumption parameters, and vibration interval penalty water consumption parameters.

[0019] Extract the initial total output sequence from the initial output parameters; obtain the unit output range and minimum number of units in operation; based on the initial total output sequence, unit output range, vibration range, and minimum number of units in operation, filter feasible unit combinations for each scheduling period and allocate unit output; obtain the unit state formed by each feasible unit combination and the corresponding allocated unit output for adjacent scheduling periods; recursively solve the objective function according to the order of scheduling periods; and backtrack from the unit state with the lowest water consumption in the last scheduling period to determine the corresponding unit state for each scheduling period to determine the final unit combination sequence and unit output allocation sequence.

[0020] The generating flow rate corresponding to the unit output and initial head for each scheduling period is retrieved from the unit water consumption curve and summarized to obtain the generating flow rate sequence. The ecological flow rate representing the lower limit of the downstream ecological discharge flow of the hydropower station is obtained, and the power generation flow rate of the power station in each scheduling period is compared with the ecological flow rate to verify whether the power generation flow rate of the power station in each scheduling period is not less than the corresponding ecological flow rate. The water abandonment flow rate is determined according to the difference between the reservoir outflow and the power generation flow rate of the power station in each scheduling period, and arranged in the order of scheduling periods to form the water abandonment flow rate sequence. The unit combination sequence, the unit output allocation sequence, the generating flow rate sequence, and the water abandonment flow rate sequence are integrated to form the scheduling operation sequence group.

[0021] As a further aspect of the present invention, the step of performing reservoir regulation and storage operations with reference to the scheduling operation sequence group and scheduling boundary parameters, and obtaining the water level regulation and storage parameters after reservoir regulation and storage, includes:

[0022] Extract the power generation flow sequence and water discharge flow sequence from the scheduling operation sequence group, summarize and arrange the power generation flow and water discharge flow in the same scheduling period in all sequences to form the total discharge flow sequence;

[0023] Extract the initial reservoir capacity, expected inflow sequence, and scheduling period length from the scheduling boundary parameters. Determine the initial water level and initial reservoir capacity at the start of the scheduling cycle as the initial water level and initial reservoir capacity of the first scheduling period, respectively. Calculate the difference between the expected inflow sequence and the total outflow sequence for each scheduling period and determine the reservoir capacity change based on the scheduling period length. Determine the corresponding final reservoir capacity based on the initial reservoir capacity and reservoir capacity change for each scheduling period. Perform reservoir regulation and storage for each scheduling period, and determine the initial and final water levels corresponding to each initial and final reservoir capacity on the water level-storage capacity curve to form a water level sequence. In each scheduling period, the final reservoir capacity of the previous scheduling period is the initial reservoir capacity of the next scheduling period.

[0024] Extract the power generation flow sequence from the scheduling operation sequence group, find the downstream water level corresponding to the power generation flow sequence on the downstream water level curve, determine the power generation head for each scheduling period based on the initial and final water levels in the water level sequence and the downstream water level, form a power generation head sequence, and determine the final water level of the last scheduling period as the simulated final water level; integrate the total discharge flow sequence, the water level sequence, the power generation head sequence, and the simulated final water level to form water level regulation parameters.

[0025] As a further aspect of the present invention, the step of determining the degree of deviation between the water level regulation parameters and the scheduling boundary parameters, readjusting the initial output parameters according to the degree of deviation until the preset convergence requirements are met, and determining the corresponding convergence result group includes:

[0026] Calculate the difference between the simulated final water level in the water level regulation parameters and the target final water level in the scheduling boundary parameters, and use it as the final water level deviation;

[0027] The initial water consumption rate is adjusted according to the final water level deviation. The adjusted initial water consumption rate, power output characteristics and typical daily power output curve are combined to form a new initial total power output sequence. The power generation head sequence in the water level regulation parameters is used as the initial head sequence for the next round.

[0028] The next round of initial head sequence is invoked to re-execute unit combination screening, unit output allocation, and reservoir regulation. When the absolute value of the final water level deviation is greater than the preset allowable deviation of the final water level, the initial water consumption rate is adjusted and the initial total output sequence and initial head sequence in the initial output parameters are updated. When the absolute value of the final water level deviation is less than or equal to the preset allowable deviation of the final water level, the iteration stops. The scheduling operation sequence group at the time of stopping iteration is determined as the converged scheduling operation sequence group, the total discharge flow sequence at the time of stopping iteration is determined as the converged total discharge flow sequence, and the water level sequence at the time of stopping iteration is determined as the converged water level sequence. The converged scheduling operation sequence group, the converged total discharge flow sequence, and the converged water level sequence are integrated to obtain the converged result group.

[0029] As a further aspect of the present invention, the constraint verification of the convergence result group and the recommendation of the operating mode based on the constraint verification result include:

[0030] Extract the converged scheduling operation sequence group from the converged result group, extract the scheduling period length from the scheduling boundary parameters, determine the power generation based on the unit output allocation sequence and scheduling period length in the converged scheduling operation sequence group, determine the power generation water consumption based on the power generation flow sequence and scheduling period length, and calculate the water consumption rate based on the power generation water consumption and power generation; integrate the power generation, power generation water consumption, and water consumption rate of the scheduling cycle as economic operation indicators;

[0031] Extract the converged scheduling operation sequence group, the converged total discharge flow sequence, and the converged water level sequence from the converged result group. Extract the starting water level, target ending water level, and expected inflow sequence from the scheduling boundary parameters. Based on the current output characteristics, perform operation constraint verification operations on the converged scheduling operation sequence group, the converged total discharge flow sequence, and the converged water level sequence to obtain constraint verification results.

[0032] When all the verification items in the constraint verification results pass, the unit combination sequence and unit output allocation sequence in the converged scheduling operation sequence group are determined as the recommended operation mode, the power generation flow sequence and water abandonment flow sequence are determined as the water use arrangement, the converged water level sequence is determined as the water level change process, and the recommended operation mode including the economic operation indicators and the constraint verification results is output; wherein, the economic operation indicators are used to represent the power generation and water consumption corresponding to the recommended operation mode, and the constraint verification results are used to indicate whether the various operation constraints corresponding to the recommended operation mode have passed the verification.

[0033] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0034] This invention integrates load generation, unit operation mode optimization, and water level feedback correction into a unified closed-loop calculation process. Given the initial and final water levels and the inflow boundary, it automatically generates a unit combination and time-of-use output scheme adapted to the current operating conditions, and continuously adjusts operating parameters based on the storage and regulation results. This enables coordination between power generation arrangements and reservoir water level changes, gradually ensuring that the water level at the end of each phase meets the planned requirements, while improving the adaptability of the recommended scheme under different operating scenarios. By uniformly verifying the final operating results and providing an economic operation evaluation, the reliability, executability, and decision-making efficiency of monthly or phased operating modes can be improved. Attached Figure Description

[0035] Figure 1 This is a general flowchart of the recommended method for economic operation of hydropower stations according to the present invention;

[0036] Figure 2 This is a flowchart of step S1 of the present invention;

[0037] Figure 3 This is a flowchart of step S2 of the present invention;

[0038] Figure 4 This is a flowchart of step S3 of the present invention;

[0039] Figure 5 This is a flowchart of step S4 of the present invention;

[0040] Figure 6 This is a flowchart of step S5 of the present invention;

[0041] Figure 7 This is a flowchart of step S6 of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0043] Please see Figure 1-7 This invention provides a technical solution, a method for recommending the economic operation of hydropower stations based on water level iteration and load processes, comprising the following steps:

[0044] S1: Obtain the scheduling boundary parameters used by the hydropower station when carrying out reservoir regulation and unit power generation.

[0045] Enter the corresponding water level and reservoir capacity data, arrange them in ascending order of water level, and use scatter plots and piecewise linear interpolation to draw the water level-reservoir capacity curve. Enter the outflow rate and the downstream water level data at the same time, arrange them in ascending order of outflow rate, and use interpolation functions to draw the downstream water level curve. Arrange the expected inflow rate sequence according to the scheduling period, calculate the product of the expected inflow rate and the length of the scheduling period for each item to obtain the expected inflow volume for each scheduling period, and then calculate the sum of all expected inflow volumes to obtain the total inflow volume within the scheduling cycle. Find the adjacent water points on both sides of the initial water level in the water level-reservoir capacity curve, calculate the difference between the initial water level and the lower water point, the difference between two adjacent water points, and the ratio of the two differences; calculate the difference in reservoir capacity corresponding to two adjacent water points, then calculate the product of the ratio and the reservoir capacity difference, and sum the product with the reservoir capacity corresponding to the lower water point to obtain the initial reservoir capacity. Perform the same calculation for the target final water level to obtain the target reservoir capacity corresponding to the target final water level. The difference between the initial reservoir capacity and the target reservoir capacity corresponding to the target final water level is calculated to obtain the usable reservoir capacity. A usable reservoir capacity greater than 0 indicates releasing reservoir capacity, a usable reservoir capacity equal to 0 indicates that the reservoir capacity remains unchanged, and a usable reservoir capacity less than 0 indicates increasing water storage. The sum of the total inflow and usable reservoir capacity within the scheduling cycle is calculated to obtain the total outflow within the scheduling cycle. The sum of the lengths of all scheduling periods is calculated to obtain the scheduling cycle length. The ratio of the total outflow within the scheduling cycle to the scheduling cycle length is calculated to obtain the average outflow rate. The average downstream water level corresponding to the average outflow rate is found on the downstream water level curve. The sum of the initial water level and the target final water level, and the ratio of the sum to 2, are calculated to obtain the average upstream water level. The difference between the average upstream water level and the average downstream water level is calculated to obtain the average head during hydropower station unit power generation.

[0046] S2: Determine the initial output parameters to be used when allocating power output to the hydropower station units based on the dispatch boundary parameters and the preset power output characteristics of the hydropower station.

[0047] The power output characteristics of a hydropower station are set based on the water level control target and load arrangement within the scheduling cycle: when the initial water level is consistent with the target final water level and stable daily output is required, the power output characteristics are set to the ecological scheduling period; when the target final water level is higher than the initial water level and the load is required to be arranged according to the typical output pattern of the same period in history, the power output characteristics are set to the normal operation period. The ratio of historical water consumption to power generation during each historical operating period is calculated to obtain the historical water consumption rate. The effective historical water consumption rates are arranged from smallest to largest, with the minimum and maximum values ​​used as the lower and upper limits of the historical water consumption rate statistical range, respectively. The sum of the lower and upper limits of the historical water consumption rate statistical range is calculated, and the ratio of this sum to 2 is used to obtain the initial water consumption rate. The product of the abandoned water flow and the length of the scheduling period is calculated for each scheduling period to obtain the abandoned water volume; the sum of the abandoned water volumes for all scheduling periods is calculated to obtain the abandoned water volume within the scheduling cycle. The difference between the total outflow and abandoned water volume within the scheduling cycle is calculated to obtain the amount of water available for power generation. Calculations continue when the available water volume for power generation is greater than 0; when the available water volume for power generation is equal to 0, the average daily output of the hydropower station is set to 0; and when the available water volume for power generation is less than 0, calculations corresponding to the current dispatch boundary parameters are stopped. The ratio of the available water volume for power generation to the initial water consumption rate is calculated to obtain the expected total power generation; the ratio of the expected total power generation to the total number of hours in the dispatch cycle is calculated to obtain the average daily output of the hydropower station.

[0048] In one embodiment, as a scenario of ecological scheduling, stable daily output, and unchanged water level, the initial water level and the target final water level are taken to be the same. The inflow is expected to remain relatively stable within the scheduling cycle, and the hydropower station's output characteristics are set to the ecological scheduling period. For each scheduling period, the product of the hydropower station's output and the number of hours in the scheduling period is calculated. The sum of all products within the same historical date is calculated, and the ratio of this sum to the total number of hours on the day is calculated to obtain the average daily output of the hydropower station for the corresponding period. The ratio of the historical hydropower station's output to the average daily output of the corresponding period is also calculated for each scheduling period to obtain the per-unit output value for each scheduling period. The per-unit output values ​​are arranged in the order of the scheduling periods, and a line graph is used to plot the typical daily output curve. The average daily output of the hydropower station is directly set as the initial total output for each scheduling period, forming a stable initial total output sequence within the day; the average head is directly set as the initial head for each scheduling period, forming an initial head sequence.

[0049] In one embodiment, assuming a water storage period, a clearly defined target water level rise, and intraday peak-valley fluctuations, the target final water level is set to be higher than the initial water level, and the hydropower station's output characteristics are set to normal operation. The hydropower station's output for each scheduling period is selected from historical normal operation dates. The ratio of the historical hydropower station's output for each scheduling period to the corresponding daily average output for that period is calculated to obtain the per-unit output value for each scheduling period. The per-unit output values ​​are arranged in order of scheduling periods, and a typical daily output curve with low daytime and high nighttime characteristics is plotted using a line graph. The product of the per-unit output value in the typical daily output curve and the hydropower station's daily average output is calculated for each scheduling period to obtain the initial total output for each scheduling period, forming an initial total output sequence with intraday peak-valley fluctuations. The average head is directly set as the initial head for each scheduling period, forming an initial head sequence.

[0050] The average head is directly set as the initial head for each scheduling period, and the initial heads are arranged in the order of the scheduling periods to form an initial head sequence. The initial total output and initial head for the same scheduling period are written into the same record, so that the initial total output sequence and the initial head sequence correspond one-to-one according to the scheduling periods, thus obtaining the initial output parameters. After completing one reservoir regulation, the difference between the upstream and downstream water levels is calculated for each scheduling period, and then the difference between this difference and the head loss is calculated to obtain the power generation head. The power generation head for each scheduling period is used to replace the initial head for the corresponding scheduling period. The minimum output, maximum output, and vibration range allowed for each operating unit are read respectively. The continuous output section that does not enter the vibration range is taken as the continuously adjustable output section for each operating unit. Then, the sum of the lower limit and the sum of the upper limit of the continuously adjustable output section for each operating unit are calculated to obtain the continuously adjustable output range allowed for the current unit combination. When the total power output of the power plant after output correction is within the continuously adjustable output range allowed by the current unit combination, the output correction amount is retained. If the output correction amount requires the addition of new units, shutdown of units, crossing of vibration intervals, or exceeding the unit output boundaries, the output correction amount is determined to be infeasible, and a new unit combination path is searched. The updated initial head sequence and the initial total output sequence are mapped one-to-one according to the scheduling period to obtain the initial output parameters used for the next round of unit output allocation, forming a calculation process that connects water level iteration with load process adjustment.

[0051] S3: Establish an objective function with the goal of minimizing water consumption, and solve the objective function with reference to the initial output parameters to determine the scheduling and operation sequence group for unit power generation, power generation water use and non-power generation discharge processes.

[0052] The operating head, unit output, and corresponding power generation flow rate of each hydropower unit are entered and sorted in ascending order of operating head and unit output. A two-dimensional interpolation function is used to construct the unit water consumption curve. The vibration interval is set using the lower and upper boundaries of the unit's prohibited operating output range. When the current operating head and unit output match the recorded point in the unit water consumption curve, the corresponding power generation flow rate is directly read. When the current unit output is between two adjacent unit output points under the same operating head, the difference between the current unit output and the lower unit output point, the difference between the two adjacent unit output points, and the ratio of the two differences are calculated. Then, the difference between the two adjacent power generation flow rates, the product of the ratio and the power generation flow rate difference, and the sum of the resulting product and the power generation flow rate corresponding to the lower unit output point are calculated to obtain the power generation water consumption parameters. Read the unit start-up and shutdown status of adjacent scheduling periods. If the unit was shut down in the previous scheduling period and started in the current scheduling period, the start-up water consumption parameter is included; if the unit was started in the previous scheduling period and shut down in the current scheduling period, the shutdown water consumption parameter is included. Other start-up and shutdown statuses are not included in the corresponding start-up and shutdown water consumption parameters. Compare the unit output and vibration range of adjacent scheduling periods. If the output of two units is on the same side of the vibration range, the vibration range crossing count is 0; if the output of two units is on opposite sides of the vibration range, the vibration range crossing count is 1; if the unit output falls into the vibration range in any scheduling period, the corresponding unit status is not retained. The minimum comprehensive equivalent water consumption flow rate for a given time period is calculated using the following formula:

[0053] ;

[0054] in, Indicates the first Minimum comprehensive equivalent water consumption flow rate for a given time period; Indicates the number of hydropower units; Indicates the first Taiwanese unit in The start / stop status of the unit during the time period, with 1 for the start status and 0 for the stop status; Indicates the first Taiwanese unit in The start-up and shutdown status of the generating units during a given time period; Indicates the first Taiwanese unit in Unit output during a given time period; Indicates the first Operating head during the time period; Indicates the first Taiwanese unit in The power generation water consumption parameters corresponding to the unit output and operating head for each time period; Indicates the first Water consumption parameters for the start-up unit; Indicates the first Water consumption parameters during unit shutdown; Indicates the first The unit is the first Time period up to the The number of times the vibration interval is crossed during a given time period; Indicates the first Vibration zone penalty water consumption parameters for each unit. Unit combinations are enumerated for each scheduling period, and unit output is allocated to each combination. Unit combinations with the number of operating units not less than the minimum number of operating units, whose output is within the unit output range and avoids the vibration zone, and whose sum of output of all operating units equals the initial total output of the corresponding scheduling period are selected as feasible combinations. For each unit combination, the comprehensive equivalent water consumption flow is calculated using the formula. This calculated comprehensive equivalent water consumption flow is used as the state transition water consumption for the corresponding unit combination from the previous scheduling period to the current scheduling period. The cumulative comprehensive equivalent water consumption of each unit's state path in the previous scheduling period is calculated by summing the corresponding state transition water consumption, resulting in the cumulative comprehensive equivalent water consumption of each unit's state path in the current scheduling period. When multiple transition paths exist for the same current unit state, only the transition path with the minimum cumulative comprehensive equivalent water consumption is retained. The calculation is repeated in sequence according to the scheduling period to obtain the cumulative comprehensive equivalent water consumption of each unit in the last scheduling period, and the terminal unit with the smallest cumulative comprehensive equivalent water consumption is taken as the backtracking starting point.

[0055] In one embodiment, during the ecological scheduling period, under the scenario of stable daily output and unchanged water level, the minimum number of operating units required to be maintained is read, and the read value is directly set as the minimum number of units in operation; the minimum and maximum output allowed for each hydropower unit are read to form the unit output range; the lower and upper boundaries of the prohibited output of the units are read to form the vibration interval. The operating and shutdown status of available units are arranged for each scheduling period, the number of operating units in each unit combination is counted, and unit combinations with fewer operating units than the minimum number of units in operation are deleted; the output of shut-down units is set to 0, and the output of operating units is set within the unit output range and avoids the vibration interval; the difference between the initial total output and the sum of the outputs of all operating units is calculated, and the difference is allocated to the operating units that still have adjustable output space, so that the sum of the outputs of all operating units equals the initial total output. Calculate the comprehensive equivalent water consumption for single large unit operation, multiple large unit operation, small unit and large unit joint operation, and other feasible unit combinations. Add the comprehensive equivalent water consumption for each unit combination to the cumulative comprehensive equivalent water consumption of the retained path in the previous scheduling period. For each scheduling period, retain the path with the minimum cumulative comprehensive equivalent water consumption when reaching the same unit state, and record the unit state and current unit output allocation for that path in the previous scheduling period. Starting from the unit state with the minimum cumulative comprehensive equivalent water consumption in the last scheduling period, backtrack backward according to the recorded unit state in the previous scheduling period. When the backtracking result corresponds to the start-up of one small unit and one large unit in each scheduling period, form a unit combination sequence of one small unit and one large unit operating continuously. Use the unit output corresponding to the path with the minimum cumulative comprehensive equivalent water consumption in each scheduling period as the unit output allocation sequence.

[0056] In one embodiment, assuming a water storage period, a clearly defined target for water level rise, and intraday peak-valley fluctuations, the minimum number of operating units required to be maintained during the low-load and peak-load periods is read, and these read values ​​are set as the minimum number of units to be started for the corresponding scheduling period. The minimum, maximum, and prohibited output ranges for each hydropower unit are read to form the unit output range and vibration range. Based on the initial total output sequence (low during the day, high at night), unit combinations are arranged for the low-load and peak-load scheduling periods, respectively, and unit combinations that do not meet the minimum number of units to be started, the unit output range, or the vibration range requirements are deleted. The unit outputs of the retained unit combinations are allocated so that the sum of the outputs of all operating units equals the initial total output for the corresponding scheduling period. During the low-load scheduling period, the comprehensive equivalent water consumption flow corresponding to different numbers of operating units and different unit number combinations is calculated and added to the cumulative comprehensive equivalent water consumption of the previous scheduling period. During the peak-load scheduling period, the cumulative comprehensive equivalent water consumption corresponding to each unit combination that can meet the initial total output of the peak period is calculated using the same method. When the unit combination changes between adjacent scheduling periods, the start-up water consumption parameters, shutdown water consumption parameters, and vibration interval penalty water consumption parameters in the formula are included in the corresponding state transition water consumption, so that the unit combination path with frequent start-ups and shutdowns or crossing vibration intervals has a larger cumulative comprehensive equivalent water consumption. For each scheduling period, the path with the minimum cumulative comprehensive equivalent water consumption when reaching the same unit state is retained, and the process starts from the unit state with the minimum cumulative comprehensive equivalent water consumption in the last scheduling period and traces back in reverse. When the backtracking results show that the low-peak scheduling periods all correspond to the start-up of 2 large units and the peak scheduling periods all correspond to the start-up of 4 large units, a unit combination sequence of 2 large units operating in the low-peak period and 4 large units operating in the peak period is formed, and the unit output corresponding to the path with the minimum cumulative comprehensive equivalent water consumption in each scheduling period is used as the unit output allocation sequence.

[0057] The lower limit of ecological discharge flow for each scheduling period is read and set as the ecological flow, forming an ecological flow sequence according to the scheduling periods. The unit output and initial head of each operating unit are read for each scheduling period according to the unit combination sequence and unit output allocation sequence, and the corresponding power generation flow is retrieved from the unit water consumption curve. The sum of the power generation flow of all operating units in the same scheduling period is calculated to obtain the power station's power generation flow, which is then arranged in the order of the scheduling periods to form a power generation flow sequence. The power station's power generation flow is compared with the ecological flow for each scheduling period to verify whether the power station's power generation flow in each scheduling period is not less than the corresponding ecological flow. The water discharge flow is determined based on the difference between the reservoir outflow and the power station's power generation flow in each scheduling period, and then arranged in the order of the scheduling periods to form a water discharge flow sequence. The unit combination sequence, unit output allocation sequence, power generation flow sequence, and water discharge flow sequence are integrated to form a scheduling operation sequence group.

[0058] S4: Execute reservoir regulation and storage operations with reference to the scheduling operation sequence group and scheduling boundary parameters, and obtain the water level regulation and storage parameters after reservoir regulation and storage.

[0059] The power generation flow and water discharge flow are assigned to the same scheduling period number. The sum of the power generation flow and water discharge flow is calculated for each scheduling period to obtain the total discharge flow. When both types of flow are 0, the total discharge flow is set to 0; when either flow is less than 0, the total discharge flow for the corresponding scheduling period is not retained; when both types of flow are non-negative, the total discharge flow for each scheduling period is arranged in the order of the scheduling periods to form a total discharge flow sequence.

[0060] In one embodiment, assuming an ecological scheduling period, stable daily power output, and unchanged water level, the water level-reservoir capacity curve is invoked, and the initial water level and initial reservoir capacity at the start of the scheduling cycle are directly set as the initial water level and initial reservoir capacity for the first scheduling period. For each scheduling period, the product of the expected inflow and the length of the scheduling period is calculated to obtain the expected inflow; the product of the total outflow and the length of the scheduling period is calculated to obtain the total outflow; the difference between the expected inflow and the total outflow is calculated to obtain the reservoir capacity change; and the sum of the initial reservoir capacity and the reservoir capacity change is calculated to obtain the final reservoir capacity. When the expected inflow equals the total outflow, the reservoir capacity change is 0, and the final reservoir capacity equals the initial reservoir capacity. The final reservoir capacity of the previous scheduling period is directly set as the starting reservoir capacity of the next scheduling period, and the initial and final water levels corresponding to each initial and final reservoir capacity are retrieved from the water level-reservoir capacity curve, forming a water level sequence according to the scheduling period order.

[0061] In one embodiment, assuming a water storage period with a clearly defined target for raising the water level and intraday peak-valley fluctuations, the water level-reservoir capacity curve is invoked. The initial water level and initial reservoir capacity at the start of the scheduling cycle are directly set as the initial water level and initial reservoir capacity for the first scheduling period. For each scheduling period, the product of the expected inflow and the length of the scheduling period is calculated to obtain the expected inflow; the product of the total outflow and the length of the scheduling period is calculated to obtain the total outflow; the difference between the expected inflow and the total outflow is calculated to obtain the reservoir capacity change; and the sum of the initial reservoir capacity and the reservoir capacity change is calculated to obtain the final reservoir capacity. The final reservoir capacity of the previous scheduling period is directly set as the initial reservoir capacity of the next scheduling period. The initial and final water levels corresponding to each initial and final reservoir capacity are retrieved from the water level-reservoir capacity curve, and a water level sequence is formed according to the scheduling period order, so that the monthly water level advances daily according to the reservoir capacity change of each scheduling period.

[0062] The downstream water level curve is retrieved by querying the downstream water level corresponding to the power generation flow rate for each scheduling period. The sum of the initial and final water levels for the same scheduling period is calculated, and the ratio of this sum to 2 is calculated to obtain the average upstream water level. The difference between the average upstream and downstream water levels is calculated, and then the difference between this difference and the head loss of the water diversion system, pressure pipeline, and tailrace system is calculated to obtain the power generation head. The power generation heads for each scheduling period are arranged in sequence to form a power generation head sequence, and the final water level of the last scheduling period is directly set as the simulated final water level. The total discharge flow sequence, water level sequence, power generation head sequence, and simulated final water level are integrated to form the water level regulation parameters. The power generation head sequence is used as the initial head sequence for the next round, and the simulated final water level is used to calculate the final water level deviation, so that the reservoir regulation results enter the water level iteration process.

[0063] S5: Determine the degree of deviation between the water level regulation parameters and the scheduling boundary parameters, readjust the initial output parameters according to the degree of deviation until the preset convergence requirements are met, and determine the corresponding convergence result group.

[0064] Read the maximum allowable positive or negative deviation of the target final water level and set the read value as the allowable deviation of the final water level. Calculate the difference between the simulated final water level and the target final water level to obtain the final water level deviation. When the final water level deviation is greater than 0, the simulated final water level is higher than the target final water level; when the final water level deviation is equal to 0, the simulated final water level is the same as the target final water level; when the final water level deviation is less than 0, the simulated final water level is lower than the target final water level. Calculate the absolute value of the final water level deviation and compare it with the allowable deviation of the final water level to obtain the degree of deviation between the water level regulation parameters and the scheduling boundary parameters. The final water level deviation is used to adjust the initial water consumption rate, and the absolute value of the final water level deviation is used to determine whether to continue iterating.

[0065] The lower limit of the historical water consumption rate statistical range is directly set as the lower limit of the historical water consumption rate adjustment interval, and the upper limit of the historical water consumption rate statistical range is directly set as the upper limit of the historical water consumption rate adjustment interval. When the deviation of the final water level is greater than the allowable deviation of the final water level, the upper limit of the historical water consumption rate adjustment interval is updated to the current initial water consumption rate. The sum of the lower limit of the historical water consumption rate adjustment interval and the current initial water consumption rate is calculated, and then the ratio of the sum to 2 is calculated to obtain the adjusted initial water consumption rate. When the deviation of the final water level is less than the negative of the allowable deviation of the final water level, the lower limit of the historical water consumption rate adjustment interval is updated to the current initial water consumption rate. The sum of the current initial water consumption rate and the upper limit of the historical water consumption rate adjustment interval is calculated, and then the ratio of the sum to 2 is calculated to obtain the adjusted initial water consumption rate. When the deviation of the final water level is between the negative of the allowable deviation of the final water level and the allowable deviation of the final water level, the current initial water consumption rate is maintained. The ratio of the achievable hydropower volume to the adjusted initial water consumption rate is calculated to obtain the projected total power generation. The ratio of the projected total power generation to the total number of hours in the scheduling cycle is also calculated to obtain the average daily output of the hydropower station. When the hydropower station's output characteristics are in the ecological scheduling period, the newly obtained average daily output is directly set as the initial total output for all scheduling periods. When the hydropower station's output characteristics are in the normal operation period, the product of the per-unit output value in the typical daily output curve and the newly obtained average daily output is calculated for each scheduling period to update the initial total output sequence. The hydropower head sequence is directly set as the initial head sequence for the next round. The updated initial total output sequence and the initial head sequence for the next round are then matched one-to-one according to the scheduling periods to re-form the initial output parameters. The average daily output and time-of-use load are updated through feedback from the final water level deviation, forming a closed-loop control of the load process.

[0066] The rated capacity of the hydropower station is read from its rated capacity record, or the ratio of the sum of the station's total output during each scheduling period within the scheduling cycle to the number of scheduling periods is calculated to obtain the representative output. The rated capacity or representative output of the hydropower station is then directly set as the output benchmark. Weighting coefficient. and weighting coefficients All are set within the range of greater than 0 and less than or equal to 1, i.e. , For the initial calculation, you can... and All values ​​are set to 0.5 to ensure that the total power output correction range for each scheduling period and the smoothness of the correction process in adjacent scheduling periods have the same effect; when it is necessary to reduce the power output correction range for a single scheduling period, the value is increased. Compared to The value of ; when it is necessary to reduce the sudden change in output correction amount between adjacent scheduling periods, increase . Compared to The value of is maintained during the same calculation. and Unchanged. With the unit combination fixed, the total power output correction for each scheduling period is used as the decision variable for the inner-level quadratic programming. The objective function for time-of-use power output reallocation is:

[0067] ;

[0068] in, This represents the objective function for time-sharing power output reallocation; This represents the sequence formed by the total power output correction of the power station during each scheduling period; Indicates the number of scheduling periods; Indicates the first Total power output correction for the time period; Indicates the first Total power output correction for the time period; Indicates the output reference; This represents the weighting coefficient corresponding to the correction range of the total power output of the power station in each dispatch period, with a value range of [value missing]. ; This represents the weighting coefficient corresponding to the change in the total power output correction of the power station during adjacent dispatch periods, with a value range of [value missing]. .

[0069] Under the conditions of satisfying the linear correction constraint for the final water level and various operational constraints, the optimal time-sharing output correction sequence is: ;in, This represents the sequence of total power output corrections that minimizes the time-of-use power output distribution objective function. Substituting each candidate power plant's total power output correction sequence into the time-of-use power output distribution objective function, the objective function value for each candidate sequence is calculated. Candidate sequences that do not satisfy the final water level linear correction constraint, unit output range, vibration range, and continuously adjustable output range are deleted. The sequence with the smallest objective function value among the remaining candidate sequences is selected as the minimum. Calculate the corresponding initial total output for each scheduling period. The sum of the total output corrections for the power station yields the corrected initial total output sequence. The corrected initial total output sequence is used to re-enumerate feasible unit combinations and recalculate the comprehensive equivalent water consumption and cumulative comprehensive equivalent water consumption corresponding to each unit combination, so that the unit combination sequence and the unit output allocation sequence are updated with the output correction results.

[0070] The linear correction constraint for the final water level is: ;in, This indicates that within the current unit configuration, operating head, and continuously adjustable output range, the [number]th [unit]... The final water level change corresponding to the change in unit output over a time period; Indicates the first Total power output correction for the time period; Indicates the target final water level; This indicates the current simulated final water level. The system reads the adjacent output points and corresponding power generation flows located on either side of the current output in the current unit combination water consumption curve. It calculates the ratio of the difference between the two power generation flows to the difference between the two unit outputs. The product of this ratio and the scheduling period length yields the time-period water volume change corresponding to the unit output change. This time-period water volume change is added to the final reservoir capacity, and the changed final water level is retrieved from the water level-capacity curve. The difference between the changed final water level and the original final water level is calculated. Calculation per scheduling period and The product of the products is calculated, and then the sum of all products is calculated. If the sum of the products is not equal to the difference between the target final water level and the current simulated final water level, the corresponding candidate power station total output correction sequence is deleted. If the sum of the products is equal to the difference between the target final water level and the current simulated final water level, the corresponding candidate sequence is retained within the comparison range of the time-sharing output redistribution objective function.

[0071] When the corrected initial total output is within the continuously adjustable output range allowed by the current unit combination, the unit combination selection, unit output allocation, and reservoir regulation are re-executed using the corrected initial total output sequence. If the corrected initial total output requires changes to unit start-up / shutdown status, crossing vibration ranges, or exceeding the unit output range, the unit combination is re-selected. The difference between the simulated final water level and the target final water level is recalculated to obtain a new final water level deviation. If the absolute value of the new final water level deviation is greater than the allowable deviation, the initial water consumption rate is adjusted and the initial output parameters are updated. If the absolute value of the new final water level deviation is less than or equal to the allowable deviation, iteration is stopped. The scheduling operation sequence group at the time of iteration cessation is determined as the converged scheduling operation sequence group, the total discharge flow sequence at the time of iteration cessation is determined as the converged total discharge flow sequence, and the water level sequence at the time of iteration cessation is determined as the converged water level sequence. By integrating the converged scheduling and operation sequence group, the converged total discharge flow sequence, and the converged water level sequence, a converged result group is obtained, thus completing the water level iteration and load process closed-loop control.

[0072] S6: Perform constraint verification on the convergence result group, and recommend the running mode based on the constraint verification results.

[0073] Extract the unit output allocation sequence and power generation flow sequence from the converged scheduling operation sequence group, and extract the scheduling period length from the scheduling boundary parameters. Calculate the product of each unit's output and the number of hours in the scheduling period for each scheduling period to obtain the power generation of each unit in each scheduling period. Then, calculate the sum of the power generation of all units and all scheduling periods to obtain the power generation of the scheduling cycle. Calculate the product of power generation flow and the number of seconds in the scheduling period for each scheduling period to obtain the water consumption for power generation in each scheduling period. Then, calculate the sum of the water consumption for power generation in all scheduling periods to obtain the water consumption for power generation of the scheduling cycle. Calculate the ratio of water consumption for power generation in the scheduling cycle to power generation in the scheduling cycle to obtain the water consumption rate. Combine the power generation in the scheduling cycle, water consumption for power generation in the scheduling cycle, and water consumption rate to form an economic operation index.

[0074] In one embodiment, under the scenario of ecological scheduling, stable daily power output, and unchanged water level, the minimum and maximum allowable power output of each hydropower unit are read to form the unit output range; the lower and upper boundaries of the prohibited power output of the units are read to form the vibration range; the minimum number of operating units is read to form the minimum number of units in operation; the lower limit of ecological discharge flow is read to form the ecological flow; and the maximum allowable positive and negative deviation of the target final water level is read to form the allowable deviation of the final water level. The sum of the power output of one small unit and one large unit is calculated for each scheduling period and compared with the initial total power output of the corresponding scheduling period; the unit output is compared with the unit output range and vibration range for each unit; the number of operating units is compared with the minimum number of units in operation; and the power station's power generation flow or total discharge flow is compared with the ecological flow; the difference between the final water level at the end of the scheduling cycle and the initial water level at the beginning of the scheduling cycle is calculated, and the absolute value of the difference between the final water level and the target final water level is calculated. The comparison results are written into the operation sequence verification item, the discharge flow verification item, and the water level verification item, respectively, to obtain the constraint verification results corresponding to the ecological scheduling period.

[0075] In one embodiment, assuming a water storage period, a clearly defined target water level rise, and intraday peak-valley fluctuations, the following parameters are read: unit output range and vibration range; minimum number of units in operation; ecological flow; load increase and decrease; and allowable deviation of the final water level. For each scheduling period, the unit output, output range, and vibration range corresponding to two large units operating during off-peak hours and four large units operating during peak hours are compared. The number of units in operation is compared with the minimum number of units in operation. The difference in total power station output between adjacent scheduling periods is calculated and compared with the load increase and decrease. The power station's generating flow or total discharge flow is compared with the ecological flow. The water level sequence is compared with the target final water level by date, and the initial total output during daytime scheduling periods is compared with the initial total output during nighttime scheduling periods. The comparison results are written into the operation sequence verification item, discharge flow verification item, and water level verification item, respectively, to obtain the constraint verification results corresponding to the normal operation period.

[0076] In one embodiment, under the scenario of ecological scheduling, stable daily power output, and unchanged water level, the operation sequence verification items, discharge flow verification items, and water level verification items are summarized to obtain the constraint verification results. When all verification items pass, the unit combination sequence and unit output allocation sequence of one small unit and one large unit operating continuously in the scheduling operation sequence group after water level iteration and load process closed-loop control convergence are determined as the recommended operation mode. The power generation flow sequence and water abandonment flow sequence are determined as the water use arrangement. The converged water level sequence is determined as the water level change process. The recommended operation mode including economic operation indicators and constraint verification results is output, as shown in Table 1.

[0077] In one embodiment, assuming a water storage period, a clearly defined target for raising the water level, and intraday peak-valley fluctuations, the operation sequence verification items, discharge flow verification items, and water level verification items are summarized to obtain constraint verification results. When all verification items pass, the unit combination sequence and unit output allocation sequence of the scheduling operation sequence group after convergence of water level iteration and load process closed-loop control are determined as the recommended operation mode. The power generation flow sequence and water abandonment flow sequence are determined as the water use arrangement. The converged water level sequence is determined as the water level change process. The recommended operation mode, including economic operation indicators and constraint verification results, is output, as shown in Table 2.

[0078] Table 1 compares the economic operating parameters of different unit combinations during the ecological dispatch period:

[0079] Option A Two large machines during off-peak hours, four large machines during peak hours 3243 3260 900 145 2909.36 9.02 2.33 Option B Three large machines during off-peak hours and four large machines during peak hours. 3243 3260 900 145 2890.81 8.96 2.34

[0080] Table 1 compares the average daily output, daily power generation, and water consumption rate of the 1 small unit + 1 large unit scheme and the 2 large unit scheme, which can intuitively reflect the economic differences of different unit combinations under the same water level control target and inflow conditions. Among them, the 1 small unit + 1 large unit scheme has higher average daily output and daily power generation, and lower water consumption rate. Therefore, it is beneficial to improve the economic efficiency of power generation while meeting the requirements of stable daily output, constant water level, and minimum number of units in operation during the ecological dispatch period. It also provides data basis for determining the recommended operation mode of continuous operation of 1 small unit and 1 large unit.

[0081] Table 2 compares the economic operating parameters of different unit combinations during the water storage period:

[0082] Option A Two large machines during off-peak hours, four large machines during peak hours 3243 3260 900 145 2909.36 9.02 2.33 Option B Three large machines during off-peak hours and four large machines during peak hours. 3243 3260 900 145 2890.81 8.96 2.34 Option C Four large machines during off-peak hours and four large machines during peak hours. 3243 3260 900 145 2854.77 8.85 2.37

[0083] Table 2 compares the daily and monthly power generation and water consumption rates of three operating scenarios: 2 large generating units during off-peak hours and 4 large generating units during peak hours; 3 large generating units during off-peak hours and 4 large generating units during peak hours; and 4 large generating units during off-peak hours and 4 large generating units during peak hours. This comparison reflects the impact of different numbers of generating units operating during off-peak hours on the economic operation during the water storage period. The scenario with 2 large generating units during off-peak hours and 4 large generating units during peak hours has the highest daily and monthly power generation and the lowest water consumption rate. This approach is beneficial for meeting the low output characteristics during the day and high output at night, as well as the target final water level requirements, while reducing the number of generating units operating during off-peak hours, thus improving the overall monthly power generation efficiency. It also provides data for determining the recommended operating mode of 2 large generating units during off-peak hours and 4 large generating units during peak hours.

[0084] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for recommending the economic operation of hydropower stations based on water level iteration and load processes, characterized in that: Includes the following steps: Obtain the scheduling boundary parameters used by the hydropower station when carrying out reservoir regulation and unit power generation; Based on the dispatch boundary parameters and the preset power output characteristics of the hydropower station, determine the initial power output parameters to be used when allocating power output to the hydropower station units; Establish an objective function with the goal of minimizing water consumption, and solve the objective function with reference to the initial output parameters to determine the scheduling and operation sequence group for unit power generation, power generation water use and non-power generation discharge processes; The reservoir regulation and storage operation is performed with reference to the scheduling operation sequence group and scheduling boundary parameters to obtain the water level regulation and storage parameters after the reservoir regulation and storage. Determine the degree of deviation between the water level regulation parameters and the scheduling boundary parameters, readjust the initial output parameters according to the degree of deviation until the preset convergence requirements are met, and determine the corresponding convergence result group; Perform constraint verification on the convergence result set, and recommend the operation mode based on the constraint verification results.

2. The method for recommending economic operation of hydropower stations based on water level iteration and load process according to claim 1, characterized in that, The scheduling boundary parameters include: the initial water level at the start of the reservoir scheduling cycle and the target final water level at the end of the scheduling cycle; the initial reservoir capacity determined according to the preset water level-reservoir capacity curve and the initial water level; the expected inflow sequence for each scheduling period, the number of scheduling periods included in the expected inflow sequence, the length of the scheduling periods, and the scheduling cycle duration calculated based on the number of scheduling periods and the length of the scheduling periods; the total outflow within the scheduling cycle determined according to the expected inflow sequence, the initial reservoir capacity, and the target reservoir capacity corresponding to the target final water level; and the average head of the hydropower station units during power generation, determined according to the preset downstream water level curve, the initial water level, and the target final water level.

3. The method for recommending economic operation of hydropower stations based on water level iteration and load process according to claim 2, characterized in that, The initial output parameters used to determine the power output allocation of hydropower station units based on scheduling boundary parameters and preset power output characteristics include: Extract the total outflow of water within the scheduling cycle from the scheduling boundary parameters, and simultaneously obtain the historical water consumption rate statistical range representing the water consumption level corresponding to the power generation and the expected water abandonment within the scheduling cycle. Select the median value of the historical water consumption rate statistical range to obtain the initial water consumption rate. Calculate the generateable water volume based on the total outflow of water within the scheduling cycle and the expected water abandonment. Calculate the average daily power output of the hydropower station based on the generateable water volume, the initial water consumption rate, and the duration of the scheduling cycle. The power output of hydropower stations during each scheduling period in the same historical period is obtained. Based on the power output of hydropower stations during each scheduling period in the same historical period and the average daily power output of the corresponding hydropower stations, the per-unit value of power output for each scheduling period is determined. The per-unit values ​​of power output are arranged in the order of scheduling periods to construct a typical daily power output curve. The power output characteristics currently adopted are obtained. Based on the typical daily power output curve and different power output characteristics, the initial total power output for each scheduling period is determined to form an initial total power output sequence. The average head in the scheduling boundary parameters is set as the initial head for each scheduling period. The initial heads are arranged in the order of the scheduling periods to form an initial head sequence. The initial total output sequence and the initial head sequence are integrated as the initial output parameters.

4. The method for recommending economic operation of hydropower stations based on water level iteration and load process according to claim 3, characterized in that, The establishment of an objective function with the goal of minimizing water consumption, and the solution of the objective function with reference to the initial output parameters, to determine the scheduling and operation sequence set for unit power generation, power generation water use, and non-power generation discharge processes, includes: The system obtains the power generation flow rate corresponding to each hydropower unit under different operating heads and unit outputs, and constructs the unit water consumption curve. Based on the power generation flow rate corresponding to the unit output and operating head in the unit water consumption curve, the power generation water consumption parameters are determined. The system obtains the start-up and shutdown status of each unit within the scheduling cycle, and determines the start-up water consumption parameters and shutdown water consumption parameters based on the start-up and shutdown status of each unit. The system obtains the vibration interval representing the prohibited operating output range of the unit, and determines the vibration interval penalty water consumption parameters based on the relationship between the unit output and the vibration interval in adjacent scheduling periods. An objective function is established to minimize the sum of the power generation water consumption parameters, start-up water consumption parameters, shutdown water consumption parameters, and vibration interval penalty water consumption parameters. Extract the initial total output sequence from the initial output parameters; obtain the unit output range and minimum number of units in operation; based on the initial total output sequence, unit output range, vibration range, and minimum number of units in operation, filter feasible unit combinations for each scheduling period and allocate unit output; obtain the unit state formed by each feasible unit combination and the corresponding allocated unit output for adjacent scheduling periods; recursively solve the objective function according to the order of scheduling periods; and backtrack from the unit state with the lowest water consumption in the last scheduling period to determine the corresponding unit state for each scheduling period to determine the final unit combination sequence and unit output allocation sequence. The generating flow rate corresponding to the unit output and initial head for each scheduling period is retrieved from the unit water consumption curve and summarized to obtain the generating flow rate sequence. The ecological flow rate representing the lower limit of the downstream ecological discharge flow of the hydropower station is obtained, and the power generation flow rate of the power station in each scheduling period is compared with the ecological flow rate to verify whether the power generation flow rate of the power station in each scheduling period is not less than the corresponding ecological flow rate. The water abandonment flow rate is determined according to the difference between the reservoir outflow and the power generation flow rate of the power station in each scheduling period, and arranged in the order of scheduling periods to form the water abandonment flow rate sequence. The unit combination sequence, the unit output allocation sequence, the generating flow rate sequence, and the water abandonment flow rate sequence are integrated to form the scheduling operation sequence group.

5. The method for recommending economic operation of hydropower stations based on water level iteration and load process according to claim 4, characterized in that, The process of performing reservoir regulation and storage operations by referring to the scheduling operation sequence group and scheduling boundary parameters, and obtaining the water level regulation and storage parameters after reservoir regulation and storage includes: Extract the power generation flow sequence and water discharge flow sequence from the scheduling operation sequence group, summarize and arrange the power generation flow and water discharge flow in the same scheduling period in all sequences to form the total discharge flow sequence; Extract the initial reservoir capacity, expected inflow sequence, and scheduling period length from the scheduling boundary parameters. Determine the initial water level and initial reservoir capacity at the start of the scheduling cycle as the initial water level and initial reservoir capacity of the first scheduling period, respectively. Calculate the difference between the expected inflow sequence and the total outflow sequence for each scheduling period and determine the reservoir capacity change based on the scheduling period length. Determine the corresponding final reservoir capacity based on the initial reservoir capacity and reservoir capacity change for each scheduling period. Perform reservoir regulation and storage for each scheduling period, and determine the initial and final water levels corresponding to each initial and final reservoir capacity on the water level-storage capacity curve to form a water level sequence. In each scheduling period, the final reservoir capacity of the previous scheduling period is the initial reservoir capacity of the next scheduling period. Extract the power generation flow sequence from the scheduling operation sequence group, find the downstream water level corresponding to the power generation flow sequence on the downstream water level curve, determine the power generation head for each scheduling period based on the initial and final water levels in the water level sequence and the downstream water level, form a power generation head sequence, and determine the final water level of the last scheduling period as the simulated final water level; integrate the total discharge flow sequence, the water level sequence, the power generation head sequence, and the simulated final water level to form water level regulation parameters.

6. The method for recommending economic operation of hydropower stations based on water level iteration and load process according to claim 5, characterized in that, The process of determining the degree of deviation between the water level regulation parameters and the scheduling boundary parameters, readjusting the initial output parameters based on the degree of deviation until the preset convergence requirements are met, and determining the corresponding convergence result set includes: Calculate the difference between the simulated final water level in the water level regulation parameters and the target final water level in the scheduling boundary parameters, and use it as the final water level deviation; The initial water consumption rate is adjusted according to the final water level deviation. The adjusted initial water consumption rate, power output characteristics and typical daily power output curve are combined to form a new initial total power output sequence. The power generation head sequence in the water level regulation parameters is used as the initial head sequence for the next round. The next round of initial head sequence is invoked to re-execute unit combination screening, unit output allocation, and reservoir regulation. When the absolute value of the final water level deviation is greater than the preset allowable deviation of the final water level, the initial water consumption rate is adjusted and the initial total output sequence and initial head sequence in the initial output parameters are updated. When the absolute value of the final water level deviation is less than or equal to the preset allowable deviation of the final water level, the iteration stops. The scheduling operation sequence group at the time of stopping iteration is determined as the converged scheduling operation sequence group, the total discharge flow sequence at the time of stopping iteration is determined as the converged total discharge flow sequence, and the water level sequence at the time of stopping iteration is determined as the converged water level sequence. The converged scheduling operation sequence group, the converged total discharge flow sequence, and the converged water level sequence are integrated to obtain the converged result group.

7. The method for recommending economic operation of hydropower stations based on water level iteration and load process according to claim 6, characterized in that, The constraint verification of the convergence result set, and the recommended operation mode based on the constraint verification results, include: Extract the converged scheduling operation sequence group from the converged result group, extract the scheduling period length from the scheduling boundary parameters, determine the power generation based on the unit output allocation sequence and scheduling period length in the converged scheduling operation sequence group, determine the power generation water consumption based on the power generation flow sequence and scheduling period length, and calculate the water consumption rate based on the power generation water consumption and power generation; integrate the power generation, power generation water consumption, and water consumption rate of the scheduling cycle as economic operation indicators; Extract the converged scheduling operation sequence group, the converged total discharge flow sequence, and the converged water level sequence from the converged result group. Extract the starting water level, target ending water level, and expected inflow sequence from the scheduling boundary parameters. Based on the current output characteristics, perform operation constraint verification operations on the converged scheduling operation sequence group, the converged total discharge flow sequence, and the converged water level sequence to obtain constraint verification results. When all the verification items in the constraint verification results pass, the unit combination sequence and unit output allocation sequence in the converged scheduling operation sequence group are determined as the recommended operation mode, the power generation flow sequence and water abandonment flow sequence are determined as the water use arrangement, the converged water level sequence is determined as the water level change process, and the recommended operation mode including the economic operation indicators and the constraint verification results is output; wherein, the economic operation indicators are used to represent the power generation and water consumption corresponding to the recommended operation mode, and the constraint verification results are used to indicate whether the various operation constraints corresponding to the recommended operation mode have passed the verification.

8. The method for recommending economic operation of hydropower stations based on water level iteration and load process according to claim 3, characterized in that, The output characteristics include ecological dispatch period and normal operation period. When the output characteristics are in the ecological dispatch period, the average daily output of the hydropower station is set as the initial total output for each dispatch period. When the output characteristics are in the normal operation period, the initial total output for each dispatch period is calculated based on the per-unit output value in the typical daily output curve and the average daily output of the hydropower station.

9. The method for recommending economic operation of hydropower stations based on water level iteration and load process according to claim 4, characterized in that, The feasible unit combination means that the number of operating units is not less than the minimum number of operating units, the output of each operating unit is within the unit output range and avoids the vibration range, and the sum of the output of each operating unit is equal to the initial total output of the corresponding scheduling period.

10. The method for recommending economic operation of hydropower stations based on water level iteration and load process according to claim 7, characterized in that, The verification items include the operation sequence verification item set for the converged scheduling operation sequence group, the discharge flow verification item set for the converged total discharge flow sequence, and the water level verification item set for the converged water level sequence.

Images