Evaluation method for water storage level of cascade reservoirs

Abstract

The application discloses a kind of cascade reservoir water storage level evaluation method, it is related to reservoir regulation technical field.Evaluation method includes the following steps: obtaining cascade reservoir relevant basic data;Determine cascade reservoir water storage regulation period and calculation period;Obtain the water storage reservoir capacity of each reservoir in each calculation period of each year water storage regulation period;Yearly calculate the overall water storage reservoir capacity of cascade reservoir in each calculation period of cascade reservoir water storage regulation period, and yearly obtain the annual minimum water storage reservoir capacity in all calculation periods in cascade reservoir water storage regulation period;Build the distribution function of annual minimum water storage reservoir capacity of cascade reservoir;Cascade reservoir water storage level evaluation system is built.The method of the application has the advantages of being simple and practical, reasonable and reliable, easy to popularize, etc.According to the regulation capacity of cascade reservoir, the inflow situation and the water storage state, the index system for dynamically evaluating the water storage level of cascade reservoir is constructed, which can quickly evaluate the current water storage level of cascade reservoir and guide the future dispatching operation strategy.

Description

Technical Field

[0001] This invention relates to the field of reservoir scheduling technology, specifically to a method for evaluating the water storage level of cascade reservoirs. Background Technology

[0002] With the large-scale construction and operation of reservoir groups, the contradiction between water storage and power generation in cascade reservoirs at the end of the flood season has become increasingly prominent. On the one hand, in order not to affect the comprehensive benefits during the dry season, reservoirs need to appropriately control the outflow to ensure that cascade reservoirs store as much water as possible; on the other hand, each reservoir power station needs to increase the power generation flow in a timely manner to meet the annual power generation assessment targets. Especially in typical dry years, how to balance the short-term power generation benefits and the long-term water replenishment benefits of cascade reservoirs is a complex problem faced in real-time scheduling. At the same time, due to differences in their flood control and power generation tasks, the start and end times of reservoir water storage, the water storage process, and the composition of inflows are different, resulting in a certain degree of asynchrony in the water storage of cascade reservoirs, which means that it is difficult for cascade reservoirs to reach full capacity simultaneously.

[0003] Currently, due to the lack of evaluation methods for the water storage levels of cascade reservoirs, scheduling and operation management units typically formulate scheduling strategies with the goal of maximizing water storage capacity to guide the operation of cascade reservoirs during the water storage period. This strategy comes at the cost of sacrificing the annual power generation of the cascade reservoirs. Especially in typical dry years, how to balance the energy storage and power generation of cascade reservoirs with limited water volume is an urgent problem to be solved. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, the present invention aims to provide a method for evaluating the water storage level of cascade reservoirs, enabling dynamic evaluation and scheduling of the water storage level of cascade reservoirs. Based on the fullness of the cascade reservoirs and the inflow level, the water storage strategy can be adjusted in a timely manner, providing a strong reference for the scheduling and operation decision-making of cascade reservoirs.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for evaluating the water storage level of cascade reservoirs, characterized by the following steps:

[0007] 1) Obtain relevant basic data on the cascade reservoirs;

[0008] 2) Based on the aforementioned basic data, determine the water storage scheduling period and calculation time period for the cascade reservoirs;

[0009] 3) Conduct runoff regulation calculations annually based on long-term runoff data to obtain the reservoir capacity for each calculation period during the annual water storage scheduling period of each reservoir;

[0010] 4) Based on the reservoir capacity, calculate the overall reservoir capacity of all reservoirs in each calculation period during the cascade reservoir water storage scheduling period each year, and obtain the annual minimum storage capacity and minimum storage capacity matrix in each calculation period during the cascade reservoir water storage scheduling period each year.

[0011] 5) Construct the distribution function of the minimum annual storage capacity of the cascade reservoirs;

[0012] 6) Based on the distribution function of the minimum annual storage capacity, a cascade reservoir water storage level evaluation system is constructed to evaluate the water storage level of cascade reservoirs in different grades.

[0013] Preferably, in step 1), the basic data includes cascade reservoir engineering characteristic data, scheduling and operation mode, and long-term runoff data; the cascade reservoir engineering characteristic data includes the normal water level, dead water level, and water level-storage capacity curve of each reservoir included in the evaluation scope; the scheduling and operation mode includes the start and end time of the water storage period of each reservoir, the water storage process, and the scheduling procedures.

[0014] Furthermore, the duration of the long-series runoff data is no less than 30 years.

[0015] Preferably, step 2) includes:

[0016] 2.1) Based on the time scale of the annual runoff series in the long-term runoff data of cascade reservoirs, a unified time step is set for the scheduling calculation during the water storage period of cascade reservoirs;

[0017] 2.2) Based on the scheduling procedures of each reservoir, according to the start and end times of the water storage period of each reservoir, the earliest start time and the latest time to be filled are obtained as the start time and full time of the cascade reservoirs, respectively, so as to determine the water storage scheduling period of the cascade reservoirs and obtain the duration of water storage of the cascade reservoirs.

[0018] 2.3) Based on the unified time step, the duration of water storage in the cascade reservoirs each year is divided into n calculation periods.

[0019] Preferably, step 3) includes:

[0020] 3.1) Based on the scheduling and operation mode of cascade reservoirs, a joint runoff regulation model for cascade reservoir groups is constructed;

[0021] 3.2) Based on the constructed joint runoff regulation model of the cascade reservoir group, the long series of runoff data is used to carry out runoff regulation calculation of the cascade reservoir group, and the water storage capacity of each reservoir in each calculation period during the water storage scheduling period of the cascade reservoirs is calculated year by year.

[0022] Preferably, step 4) includes:

[0023] 4.1) Based on the reservoir capacity, the reservoir capacity matrix for each calculation period during the water storage scheduling period is obtained year by year:

[0024]

[0025] In the formula: V 蓄,i Let be the reservoir capacity matrix of reservoir i; Let i be the water storage capacity of reservoir i in year m and calculation period k. Let V be the reservoir capacity of reservoir i in year m and calculation period k. i,dwl Let be the storage capacity of reservoir i at dead water level; i = 1, 2, ..., s-1, s, where s is the total number of reservoirs in the cascade reservoirs; m = 1, 2, ..., y-1, y, where y is the duration of long-term runoff data in years; k = 1, 2, ..., n-1, n, where n is the total number of calculation periods during the water storage and scheduling period of the cascade reservoirs.

[0026] 4.2) The overall water storage capacity of the cascade reservoirs is statistically analyzed year by year and time period by period, and the overall water storage capacity matrix of the cascade reservoirs is obtained; the calculation method of the overall water storage capacity is as follows:

[0027]

[0028] in, The total water storage capacity of all reservoirs in the cascade reservoir system in year m and calculation period k is given.

[0029] The overall water storage capacity matrix of the cascade reservoirs is as follows:

[0030]

[0031] V 蓄,tot This is a matrix showing the overall water storage capacity of the cascade reservoirs over the years.

[0032] 4.3) Calculate the maximum overall water storage capacity of the cascade reservoirs for each year across all calculation periods, and obtain the matrix of the maximum overall water storage capacity of the cascade reservoirs.

[0033]

[0034] in, This represents the maximum overall water storage capacity of the cascade reservoirs across all calculation periods within year m.

[0035] 4.4) Based on the maximum overall storage capacity of the cascade reservoirs, the minimum storage capacity of each cascade reservoir during all calculation periods within the annual water storage scheduling period is obtained year by year, thereby obtaining the minimum storage capacity matrix of the cascade reservoirs:

[0036]

[0037] in, V is the minimum storage capacity matrix for cascade reservoirs; i,nwl The reservoir capacity is the normal water level of reservoir i. This represents the minimum annual storage capacity of the cascade reservoir during all calculation periods within the m-th year.

[0038] Preferably, step 5) includes:

[0039] 5.1) The probability distribution of the annual minimum storage capacity of the cascade reservoirs over the years is characterized by the probability density distribution function;

[0040] 5.2) Based on the matrix of minimum storage capacity of cascade reservoirs over the years Calculate the parameters of the probability density distribution function for each element of the given set of elements;

[0041] 5.3) Based on the parameters, determine the distribution function of the annual minimum storage capacity of the cascade reservoirs over the years.

[0042] Furthermore, the probability density distribution function is obtained through the Pearson Type III distribution curve; the parameters of the probability density distribution function are calculated using the weight function method or the least squares estimation method.

[0043] Preferably, step 6) includes:

[0044] 6.1) Introduce frequency exponents P1, P2, ..., P l-1 P l , and has 0 <P1<P2<…<P l-1 <P l <1; where l is the number of frequency indices, and the value of the frequency index is determined according to the actual needs of cascade reservoir scheduling;

[0045] 6.2) Based on the distribution function, deduce the required storage capacity corresponding to different frequency indices:

[0046]

[0047] In the formula, This indicates the storage capacity of the cascade reservoirs with a frequency of P1, and so on for the others.

[0048] 6.3) Based on the storage capacity corresponding to different frequency indices, construct a cascade reservoir water storage level evaluation system; by obtaining the actual storage capacity of cascade reservoirs and comparing it with the storage capacity of each level in the cascade reservoir water storage level evaluation system, the graded evaluation of the water storage level of cascade reservoirs can be realized.

[0049] Preferably, in the cascade reservoir water storage level evaluation system, l=4, and the overall water storage situation is classified into good, relatively good, average, relatively poor, and poor.

[0050] like The overall water storage situation is good;

[0051] like The overall water storage situation is relatively good;

[0052] like The overall water storage situation is average;

[0053] like The overall water storage situation is poor;

[0054] like The overall water storage situation is poor.

[0055] Furthermore, l = 4, P1 = 0.1, P2 = 0.2, P3 = 0.5, P4 = 0.8.

[0056] This invention also discloses an evaluation system for the water storage level of cascade reservoirs, used to implement the aforementioned method for evaluating the water storage level of cascade reservoirs, characterized in that it includes:

[0057] The data storage module is used to store basic information related to the cascade reservoirs;

[0058] The module for acquiring the evaluation index system of water storage level of cascade reservoirs is used to construct the evaluation index system of water storage level of cascade reservoirs based on the basic data stored in the data storage module.

[0059] The evaluation module is used to evaluate and classify the water storage level of cascade reservoirs based on the evaluation index system for cascade reservoir water storage level.

[0060] This invention also discloses a method for scheduling water storage in cascade reservoirs, which is characterized by including:

[0061] a) The water storage levels of the cascade reservoirs are evaluated and classified using the above-mentioned evaluation method for cascade reservoir water storage levels;

[0062] b) Based on the evaluation results and the water storage situation during the extended period, propose guiding strategies for coordinating power generation and water storage in cascade reservoirs.

[0063] Furthermore, the guidance strategy includes:

[0064] If the overall water storage status is poor, the power generation flow of the cascade reservoirs will be reduced and water storage will be increased based on the extended forecast of water inflow, so that the water storage status reaches above average.

[0065] If the overall water storage situation is poor, based on the extended-period water inflow forecast, if the forecasted inflow is abundant, reduce the power generation flow of the cascade reservoirs and increase water storage to achieve a good water storage situation; if the forecasted inflow is average or low, reduce the power generation flow of the cascade reservoirs and increase water storage to achieve an average or better water storage situation.

[0066] If the overall water storage status is average, based on the extended-period water inflow forecast, if the forecasted inflow is abundant, reduce the power generation flow of the cascade reservoirs and increase water storage to achieve a good water storage status; if the forecasted inflow is average or low, reduce the power generation flow of the cascade reservoirs and increase water storage to achieve a better water storage status.

[0067] If the overall water storage situation is good or relatively good, increase the power generation flow of the cascade reservoirs and maintain the water storage situation of the cascade reservoirs at the current level.

[0068] The forecast of abundant water inflow refers to an extended-term forecast of water inflow that is more than 20% higher than the multi-year average; the forecast of general water inflow refers to an extended-term forecast of water inflow that is less than 20% higher than the multi-year average; the forecast of scarce water inflow refers to an extended-term forecast of water inflow that is more than 20% lower than the multi-year average.

[0069] This invention also discloses a cascade reservoir water storage scheduling system for implementing the above-mentioned cascade reservoir water storage scheduling method, characterized in that it includes:

[0070] The evaluation module is used to evaluate and classify the water storage levels of cascade reservoirs.

[0071] The strategy output module is used to obtain and output guiding strategies for coordinating power generation and water storage in cascade reservoirs based on the hierarchical results of the evaluation module.

[0072] The present invention also discloses a computer-readable storage medium, which is characterized in that: the computer-readable storage medium stores computer instructions, which are used to cause the computer to execute the above-mentioned evaluation method for the water storage level of cascade reservoirs or the water storage scheduling method for cascade reservoirs.

[0073] The present invention also discloses an electronic device, which is characterized in that it includes a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to perform the above-mentioned method for evaluating the water storage level of cascade reservoirs or the method for scheduling water storage in cascade reservoirs.

[0074] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0075] The method for evaluating the water storage level of cascade reservoirs disclosed in this invention has the advantages of being simple, practical, reasonable, reliable, and easy to promote. Based on the regulation capacity, inflow situation, and water storage status of cascade reservoirs, a dynamic index system for evaluating the water storage level of cascade reservoirs is constructed. This method can quickly evaluate the current water storage level of cascade reservoirs, provide guidance for future scheduling and operation strategies, and provide timely early warning of potential under-storage risks in reservoir scheduling. It conforms to the actual operation characteristics of reservoir scheduling and can provide support for reservoir operation and management departments to adjust scheduling strategies in real time.

[0076] This invention fully considers the actual operating characteristics and historical water storage patterns of cascade reservoirs, and reasonably provides evaluation indicators for the water storage level of cascade reservoirs, which are in line with the actual scheduling and operation characteristics of reservoirs.

[0077] This invention can quickly provide water storage strategies for different scheduling stages and under different inflow conditions, and adjust reservoir water storage targets in a timely manner, providing effective support for reservoir scheduling strategies. Attached Figure Description

[0078] Figure 1 This is a flowchart illustrating the implementation of a method for evaluating the water storage level of a cascade reservoir according to the present invention. Detailed Implementation

[0079] To better explain the present invention, the main contents of the present invention are further illustrated below with reference to the accompanying drawings and specific embodiments, but the contents of the present invention are not limited to the following embodiments.

[0080] like Figure 1 As shown, a method for evaluating the water storage level of cascade reservoirs includes the following steps:

[0081] 1) Collect basic data related to cascade reservoirs, such as engineering characteristics, scheduling and operation methods, and long-term runoff data.

[0082] 1.1) Determine the scope of reservoirs to be included in the evaluation. Assume there are a total of s reservoirs.

[0083] 1.2) Collect characteristic data of cascade reservoirs, including normal water level, dead water level, and water level-storage capacity curves for each reservoir; long-term runoff data series spanning y years, y≥30, with the time scale for the annual runoff series being ten-day averages or daily averages. Operational scheduling includes the start and end times of the impoundment period for each reservoir, the impoundment process, and scheduling procedures.

[0084] 2) Based on the above basic data, determine the water storage scheduling period and calculation period for the cascade reservoirs, so as to determine the water storage scheduling period and calculation period used in steps 3) and 4). Specifically, this includes:

[0085] 2.1) Based on the time scale (ten days or days) of long-term natural runoff data, a unified time step dt is set for the simulation calculation of the water storage period of each reservoir.

[0086] 2.2) Since the start time and full-fill time of each reservoir are usually different each year, the earliest start time T0 and the latest full-fill time T1 specified in the reservoir operation regulations are used as the start time and full-fill time of the cascade reservoirs, respectively. The duration of water storage in the cascade reservoirs is calculated and the duration of water storage TS is divided into n calculation periods each year, where n = TS / dt.

[0087] 3) Based on the aforementioned basic data, a joint runoff regulation model for the cascade reservoir group is constructed. Using long-term runoff data, runoff regulation calculations for the cascade reservoir group are performed to obtain the annual water storage status of each reservoir during each calculation period within the aforementioned water storage scheduling period. Specifically, this includes:

[0088] 3.1) Based on the scheduling and operation mode of cascade reservoirs, including the start and end times of water storage and the water storage process of each reservoir, a joint runoff regulation model of cascade reservoir group is constructed.

[0089] 3.2) Based on the constructed joint runoff regulation model of the cascade reservoir group, the runoff regulation calculation of the cascade reservoir group is carried out using long-term runoff data, and the water storage capacity of each reservoir in each calculation period is calculated year by year.

[0090] 4) Based on the runoff regulation calculation results, calculate the overall storage capacity and expected storage capacity of all reservoirs for each calculation period of the cascade reservoir water storage scheduling period each year, and obtain the minimum expected storage capacity and minimum expected storage capacity matrix for each year's water storage period. Specifically, this includes:

[0091] 4.1) Based on the runoff regulation calculation results, the water storage capacity matrix V of reservoir i in each year and calculation period is obtained year by year. 蓄,i :

[0092]

[0093] In the formula: Let i be the water storage capacity of reservoir i in year m and calculation period k. Let V be the reservoir capacity of reservoir i in year m and calculation period k. i,dwl Let be the reservoir capacity at dead water level i; i = 1, 2, ..., s-1, s; m = 1, 2, ..., y-1, y; k = 1, 2, ..., n-1, n.

[0094] 4.2) Statistical analysis of the overall water storage capacity of the cascade reservoirs year by year and time period by period:

[0095]

[0096] Let be the total water storage capacity of the cascade reservoir in year m and calculation period k.

[0097] Based on the overall water storage capacity of the cascade reservoirs in each year and calculation period The overall water storage capacity matrix V of the cascade reservoirs is obtained by sorting. 蓄,tot :

[0098]

[0099] 4.3) Calculate the maximum overall water storage capacity of the cascade reservoirs for all calculation periods each year, and compile the matrix of the maximum overall water storage capacity of the cascade reservoirs over the years.

[0100]

[0101] in, This represents the maximum overall water storage capacity of the cascade reservoirs across all calculation periods within the m-th year, i.e., the maximum overall water storage capacity.

[0102] 4.4) Transform the maximum storage capacity data of the cascade reservoirs to obtain the matrix of minimum storage capacity of the cascade reservoirs over the years.

[0103]

[0104] V i,nwl The reservoir capacity is the normal water level of reservoir i. This represents the minimum storage capacity of the cascade reservoir during all calculation periods within the m-th year, i.e., the minimum storage capacity in the m-th year.

[0105] 5) Construct the distribution function of the annual minimum storage capacity of the cascade reservoirs. Specifically, this includes:

[0106] 5.1) Introduce the Pearson Type III distribution curve to characterize the probability density distribution function of the annual minimum storage capacity of the cascade reservoirs over the years.

[0107]

[0108] In the formula: Γ(α) is the gamma function of α, and α, β, and a0 are the shape, scale, and location parameters of the Pearson Type III distribution curve, respectively.

[0109]

[0110] C s C v Minimum storage capacity matrix The statistical parameters are the mean, skewness coefficient, and deviation coefficient, respectively.

[0111] 5.2) Based on the minimum storage capacity matrix For each element, the weight function method or the least squares estimation method is used to... C s C v Statistical parameters are used for calculation.

[0112] 5.3) Regarding the probability density distribution function By integrating, the minimum annual storage capacity of the cascade reservoirs was derived. Distribution function:

[0113]

[0114] 6) Based on the above distribution function, an evaluation index system for the water storage level of cascade reservoirs is constructed. The distribution of the annual minimum storage capacity calculated from long-term runoff data for cascade reservoirs is used as the grading criterion to classify the storage capacity, thus constructing an evaluation index system for the water storage level of cascade reservoirs. By combining historical data and quantifying risks, the scientific, forward-looking, and safe operation of cascade reservoirs is significantly improved.

[0115] The specific methods for constructing the above-mentioned evaluation index system for the water storage level of cascade reservoirs include:

[0116] 6.1) Introduce frequency exponents P1, P2, ..., P l-1 P l And:

[0117] 0 <P1<P2<…<P l-1 <P l <1

[0118] Where l is the total number of frequency indices, and the value of the frequency index can be determined according to the actual needs of cascade reservoir scheduling. l = 4, P1 = 0.1, P2 = 0.2, P3 = 0.5, P4 = 0.8.

[0119] 6.2) Based on the minimum storage capacity distribution function mentioned above, derive the storage capacity corresponding to different frequency indices:

[0120]

[0121] In the formula: This indicates the storage capacity of the cascade reservoirs with a frequency of P1, and so on for the others.

[0122] 6.3) Based on the storage capacity corresponding to different frequency indices, construct an evaluation system for the water storage level of cascade reservoirs, and classify the overall water storage situation into good, relatively good, average, relatively poor, and poor categories:

[0123] like The overall water storage situation is good;

[0124] like The overall water storage situation is relatively good;

[0125] like The overall water storage situation is average;

[0126] like The overall water storage situation is poor;

[0127] like The overall water storage situation is poor.

[0128] By obtaining the actual storage capacity of cascade reservoirs and comparing it with the storage capacity of each level in the cascade reservoir water storage level evaluation system, a graded evaluation of the water storage level of cascade reservoirs can be achieved.

[0129] The present invention also provides a method for scheduling water storage in cascade reservoirs, comprising:

[0130] a) The water storage levels of the cascade reservoirs are evaluated and classified using the above-mentioned evaluation method for cascade reservoir water storage levels;

[0131] b) Based on the grading results and the extended-period water storage situation, and using the cascade reservoir water storage level evaluation index system, a guiding strategy for coordinating power generation and water storage in cascade reservoirs is proposed. The specific strategy is as follows:

[0132] If the overall water storage status is "poor", based on the extended forecast of water inflow, the power generation flow of the cascade reservoirs should be reduced as much as possible, and water storage should be increased to bring the water storage status to "average" or above.

[0133] If the overall water storage situation is "poor", based on the extended-period water inflow forecast, if the forecast is for abundant water, the power generation flow of the cascade reservoirs should be reduced and water storage increased to bring the water storage situation to "good". If the forecast is for average or low water, the power generation flow of the cascade reservoirs can be reduced and water storage increased to bring the water storage situation to "average" or above.

[0134] If the overall water storage status is "average", based on the extended-period water inflow forecast, if the forecast indicates abundant water inflow, the power generation flow of the cascade reservoirs should be reduced and water storage increased to achieve a "good" water storage status. If the forecast indicates average or low water inflow, the power generation flow of the cascade reservoirs can be reduced and water storage increased to achieve a "good" or higher water storage status.

[0135] If the overall water storage status is "good" or "relatively good", the power generation flow of the cascade reservoirs can be appropriately increased while maintaining the water storage status of the cascade reservoirs.

[0136] A forecast of abundant water inflow means that the water inflow predicted during the extended period is more than 20% higher than the multi-year average; a forecast of generally low water inflow means that the water inflow predicted during the extended period is less than 20% lower than the multi-year average; a forecast of scarce water inflow means that the water inflow predicted during the extended period is more than 20% lower than the multi-year average.

[0137] This invention also provides an evaluation system for the water storage level of cascade reservoirs, comprising:

[0138] The data storage module is used to store basic data related to cascade reservoirs, such as engineering characteristic data, scheduling and operation modes, and long-term runoff data.

[0139] The module for acquiring the evaluation index system of water storage level of cascade reservoirs is used to construct the evaluation index system of water storage level of cascade reservoirs based on the basic data stored in the data storage module.

[0140] The evaluation module is used to evaluate and classify the water storage level of cascade reservoirs based on the evaluation index system for cascade reservoir water storage level.

[0141] The present invention also provides a cascade reservoir water storage scheduling system, comprising:

[0142] The evaluation module is used to evaluate and classify the water storage level of cascade reservoirs based on the evaluation index system for cascade reservoir water storage level.

[0143] The strategy output module is used to obtain and output guiding strategies for coordinating power generation and water storage in cascade reservoirs based on the hierarchical results of the evaluation module.

[0144] The present invention also provides a computer-readable storage medium storing computer instructions for causing a computer to execute the above-mentioned method for evaluating the water storage level of cascade reservoirs or the method for scheduling water storage in cascade reservoirs.

[0145] The present invention also provides an electronic device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the above-mentioned method for evaluating the water storage level of cascade reservoirs or the method for scheduling water storage in cascade reservoirs.

[0146] The following uses a cascade reservoir in the upper reaches of a river as an example to illustrate the dynamic evaluation and scheduling of the reservoir's water storage level using the method proposed in this invention, including the following steps:

[0147] 1) Collect long-term natural runoff data (1959-2014) of 30 key reservoirs in the upper reaches of a river, including normal water level, dead water level, water level-storage capacity curve, start and end time of water storage period, operating water level and ten-day average.

[0148] 2) Determine the time step dt for the cascade reservoir calculation as ten days, the water storage scheduling period as August 1 to October 31, and the calculation period for each year as n = 12;

[0149] 3) Based on the scheduling and operation mode, a joint runoff regulation model for a cascade reservoir group is constructed. Using long-term runoff data from 1959 to 2014, runoff regulation calculations are carried out to calculate the water storage of each reservoir in each year and calculation period.

[0150] 4) Calculate the water storage capacity of each reservoir during the annual water storage period from August 1st to October 31st, and calculate the overall water storage capacity of all reservoirs in the cascade reservoirs for each year and each ten-day period. Based on this, calculate the maximum water storage capacity and minimum storage capacity of the cascade reservoirs for each year in all calculation periods. See Table 1 for details.

[0151] 5) Construct the distribution function of the annual minimum storage capacity of the cascade reservoirs, calculate the parameters of the probability distribution function using the least squares estimation method, and derive the minimum storage capacity of the cascade reservoirs. Distribution function curve.

[0152] 6) Introducing frequency indices P1 = 0.1, P2 = 0.2, P3 = 0.5, and P4 = 0.8, the corresponding storage capacity for different frequency indices is shown in Table 2. The tiered evaluation system corresponding to different levels of storage capacity is shown in Table 3.

[0153] Table 1: Historical Maximum and Minimum Storage Capacities of Cascade Reservoirs

[0154]

[0155] Table 2: Storage Capacity Corresponding to Different Frequency Indices

[0156] <![CDATA[Storage capacity to be reserved (100 million m 3 )]]> 91.6 52.6 16.5 9.6

[0157] Table 3: Grading Evaluation Table for Different Levels of Storage Capacity

[0158] Evaluation level good better generally Poor Difference

[0159] The scheduling method is as follows:

[0160] If the actual storage capacity is ≥9.16 billion m³ 3 If the overall water storage situation is poor, the power generation flow of the cascade reservoirs will be reduced based on the extended-period inflow forecast, and water storage will be increased to bring the water storage situation to a level of "average" or above, ensuring that the actual storage capacity is less than 5.26 billion m³. 3 .

[0161] If 5.26 billion m 3 Actual storage capacity < 9.16 billion m³ 3 If the overall water storage situation is "poor", then according to the extended-period water inflow forecast, if the forecasted inflow is abundant, the power generation flow of the cascade reservoirs will be reduced, and water storage will be increased to bring the water storage situation to "good", even if the actual storage capacity is less than 960 million cubic meters. 3 If the forecast of average or low water inflow is positive, the power generation flow of the cascade reservoirs will be reduced, and water storage will be increased to bring the water storage status to "average" or above, ensuring that the actual storage capacity is less than 5.26 billion m³. 3 .

[0162] If 1.65 billion m3 Actual storage capacity < 5.26 billion m³ 3 If the overall water storage situation is "average," then based on the extended-period water inflow forecast, if the forecast is higher than average, the power generation flow of the cascade reservoirs will be reduced, and water storage will be increased to achieve a "good" water storage situation, meaning the actual storage capacity is less than 960 million m³. 3 If the forecast of average or low water inflow is positive, the power generation flow of the cascade reservoirs will be reduced, and water storage will be increased to achieve a water storage status of "good" or above, ensuring that the actual storage capacity is less than 1.65 billion m³. 3 .

[0163] If the actual storage capacity is less than 1.65 billion m³ 3 The overall water storage status is "good" or "relatively good", which allows for increased power generation flow in the cascade reservoirs and maintenance of the water storage status at the current level.

[0164] All other unspecified parts belong to the prior art.

Claims

1. A method for evaluating the water storage level of cascade reservoirs, characterized in that: Includes the following steps: 1) Obtain relevant basic data on the cascade reservoirs; 2) Based on the aforementioned basic data, determine the water storage scheduling period and calculation time period for the cascade reservoirs; 3) Conduct runoff regulation calculations annually based on long-term runoff data to obtain the reservoir capacity for each calculation period during the annual water storage scheduling period of each reservoir; 4) Based on the reservoir capacity, calculate the overall reservoir capacity of all reservoirs in each calculation period during the cascade reservoir water storage scheduling period each year, and obtain the annual minimum storage capacity and minimum storage capacity matrix in each calculation period during the cascade reservoir water storage scheduling period each year. 5) Construct the distribution function of the minimum annual storage capacity of the cascade reservoirs; 5.1) The probability distribution of the annual minimum storage capacity of the cascade reservoirs over the years is characterized by the probability density distribution function; 5.2) Calculate the parameters of the probability density distribution function based on the elements of the minimum storage capacity matrix of cascade reservoirs over the years; the probability density distribution function is obtained through the Pearson Type III distribution curve; the parameters of the probability density distribution function are calculated using the weight function method or the least squares estimation method. 5.3) Based on the parameters, determine the distribution function of the annual minimum storage capacity of the cascade reservoirs over the years. ;in, Let P be the minimum storage capacity matrix for cascade reservoirs, where P is the frequency of occurrence. 6) Based on the distribution function of the minimum annual storage capacity, construct a cascade reservoir water storage level evaluation system to classify and evaluate the water storage level of cascade reservoirs; 6.1) Introducing the frequency index 、 、 、 、 , and has 0 < < < < < < 1; among which, l The number of frequency exponents; 6.2) Based on the distribution function, deduce the required storage capacity corresponding to different frequency indices: In the formula, Indicates the frequency of occurrence as The storage capacity of the cascade reservoirs is calculated accordingly; others follow the same principle. 6.3) Based on the storage capacity corresponding to different frequency indices, construct a cascade reservoir water storage level evaluation system; by obtaining the storage capacity of cascade reservoirs under actual conditions and comparing it with the storage capacity of each level in the cascade reservoir water storage level evaluation system, the graded evaluation of the water storage level of cascade reservoirs can be realized.

2. The evaluation method according to claim 1, characterized in that: In step 1), the basic data includes the engineering characteristic data of the cascade reservoirs, the scheduling and operation mode, and long-term runoff data; the engineering characteristic data of the cascade reservoirs includes the normal water level, dead water level, and water level-storage capacity curve of each reservoir included in the evaluation scope; the scheduling and operation mode includes the start and end time of the water storage period of each reservoir, the water storage process, and the scheduling procedures.

3. The evaluation method according to claim 1, characterized in that: Step 2) includes: 2.1) Based on the time scale of the annual runoff series in the long-term runoff data of cascade reservoirs, a unified time step is set for the scheduling calculation during the water storage period of cascade reservoirs; 2.2) Based on the scheduling procedures of each reservoir, according to the start and end times of the water storage period of each reservoir, the earliest start time and the latest time to be filled are obtained as the start time and full time of the cascade reservoirs, respectively, so as to determine the water storage scheduling period of the cascade reservoirs and obtain the duration of water storage of the cascade reservoirs. 2.3) Based on the unified time step, the duration of water storage in the cascade reservoirs each year is divided into n calculation periods.

4. The evaluation method according to claim 1, characterized in that: Step 3) includes: 3.1) Based on the scheduling and operation mode of cascade reservoirs, construct a joint runoff regulation model for cascade reservoir groups; 3.2) Based on the constructed joint runoff regulation model of the cascade reservoir group, the long series of runoff data is used to carry out runoff regulation calculation of the cascade reservoir group, and the water storage capacity of each reservoir in each calculation period during the water storage scheduling period of the cascade reservoirs is calculated year by year.

5. The evaluation method according to claim 1, characterized in that: Step 4) includes: 4.1) Based on the reservoir capacity, the reservoir capacity matrix for each calculation period during the water storage scheduling period is obtained year by year: In the formula: For reservoir i The reservoir capacity matrix; For reservoir i In the m Year, No. k The reservoir capacity for the calculation period , For reservoir i In the m Year, No. k Storage capacity for the calculation period. For reservoir i The reservoir capacity at dead water level; , s This represents the total number of reservoirs in the cascade reservoir system. , y The duration of long-term runoff data is in years. , n The total number of time periods calculated during the water storage and scheduling period of the cascade reservoirs; 4.2) The overall water storage capacity of the cascade reservoirs is statistically analyzed year by year and time period by period, and the overall water storage capacity matrix of the cascade reservoirs is obtained; the calculation method of the overall water storage capacity is as follows: ； in, For all reservoirs in the cascade reservoir system, in the [number]th [year]... m Year, No. k The total reservoir capacity during the calculation period; The overall water storage capacity matrix of the cascade reservoirs is as follows: This is a matrix showing the overall water storage capacity of the cascade reservoirs over the years. 4.3) Calculate the maximum overall water storage capacity of the cascade reservoirs for each year across all calculation periods, and obtain the matrix of the maximum overall water storage capacity of the cascade reservoirs. : in, For the cascade reservoirs in the first m The maximum overall reservoir capacity during all calculation periods within the year; 4.4) Based on the maximum overall storage capacity of the cascade reservoirs, the minimum storage capacity of each cascade reservoir during all calculation periods within the annual water storage scheduling period is obtained year by year, thereby obtaining the minimum storage capacity matrix of the cascade reservoirs: in, This is the matrix representing the minimum storage capacity of the cascade reservoirs. For reservoir i Reservoir capacity at normal water level; For the first cascade reservoir m The minimum annual storage capacity for all calculation periods within the year.

6. The evaluation method according to claim 1, characterized in that: In the aforementioned cascade reservoir water storage level evaluation system l =4, classifying the overall water storage situation into good, relatively good, average, relatively poor, and poor categories: If the actual storage capacity of the cascade reservoirs is < If so, the overall water storage situation is good; like ≤ Actual storage capacity of cascade reservoirs < Therefore, the overall water storage situation is relatively good; like ≤ Actual storage capacity of cascade reservoirs < Therefore, the overall water storage situation is average. like ≤ Actual storage capacity of cascade reservoirs < Therefore, the overall water storage situation is relatively poor. If the actual water storage capacity of the cascade reservoirs is ≥ If the overall water storage situation is poor, then the water storage situation is poor.

7. The evaluation method according to claim 1, characterized in that: l =4， =0.1， =0.2， =0.5， =0.8。 8. A system for evaluating the water storage level of cascade reservoirs, used to implement the method for evaluating the water storage level of cascade reservoirs as described in any one of claims 1 to 7, characterized in that: include: The data storage module is used to store basic information related to the cascade reservoirs; The module for acquiring the evaluation index system of water storage level of cascade reservoirs is used to construct the evaluation index system of water storage level of cascade reservoirs based on the basic data stored in the data storage module. The evaluation module is used to evaluate and classify the water storage level of cascade reservoirs based on the evaluation index system for cascade reservoir water storage level.

9. A method for scheduling water storage in cascade reservoirs, characterized in that: include: a) The water storage level of the cascade reservoirs is evaluated and classified using the evaluation method described in any one of claims 1 to 7; b) Based on the evaluation results and the water storage situation during the extended period, propose guiding strategies for coordinating power generation and water storage in cascade reservoirs.

10. The cascade reservoir water storage and scheduling method according to claim 9, characterized in that: The guidance strategies include: If the overall water storage status is poor, the power generation flow of the cascade reservoirs will be reduced and water storage will be increased based on the extended forecast of water inflow, so that the water storage status reaches above average. If the overall water storage situation is poor, based on the extended-period water inflow forecast, if the forecasted inflow is abundant, reduce the power generation flow of the cascade reservoirs and increase water storage to achieve a good water storage situation; if the forecasted inflow is average or low, reduce the power generation flow of the cascade reservoirs and increase water storage to achieve an average or better water storage situation. If the overall water storage status is average, based on the extended-period water inflow forecast, if the forecasted inflow is abundant, reduce the power generation flow of the cascade reservoirs and increase water storage to achieve a good water storage status; if the forecasted inflow is average or low, reduce the power generation flow of the cascade reservoirs and increase water storage to achieve a better water storage status. If the overall water storage situation is good or relatively good, increase the power generation flow of the cascade reservoirs and maintain the water storage situation of the cascade reservoirs at the current level.

11. A cascade reservoir water storage scheduling system, used to implement the cascade reservoir water storage scheduling method according to claim 9 or 10, characterized in that: include: The evaluation module is used to evaluate and classify the water storage levels of cascade reservoirs. The strategy output module is used to obtain and output guiding strategies for coordinating power generation and water storage in cascade reservoirs based on the hierarchical results of the evaluation module.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions for causing the computer to execute the evaluation method for the water storage level of the cascade reservoirs as described in any one of claims 1 to 7, or the water storage scheduling method for the cascade reservoirs as described in claim 9 or 10.

13. An electronic device, characterized in that: include: The system includes a memory and a processor, which are interconnected. The memory stores computer instructions, and the processor executes the computer instructions to perform the evaluation method for the water storage level of the cascade reservoirs as described in any one of claims 1 to 7, or the water storage scheduling method for the cascade reservoirs as described in claim 9 or 10.

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