Hydropower plant dry water early warning method and system based on power generation capacity trend evaluation

Abstract

The invention discloses a hydropower plant dry water early warning method and system based on power generation capacity trend evaluation, and the method comprises the steps: collecting the data of a target hydropower plant, evaluating the incoming water prediction accuracy, and dividing an incoming water prediction interval; evaluating a hydroelectric power generation demand interval, and calculating a hydroelectric energy storage and hydroelectric power generation capacity change trend based on a power generation demand interval evaluation result; according to the hydroelectric power generation capacity change trend, low water early warning is issued. According to the method, the prediction interval is divided into the acceptable prediction interval and the unacceptable prediction interval according to the incoming water prediction accuracy, so that the problem that the prediction accuracy deviation affects the early warning result is solved. A hydroelectric power generation demand interval prediction method is provided by considering power consumption demands, conventional power supplies such as coal power and new energy power generation capacity changes. And in combination with the relationship among hydroelectric energy storage, hydroelectric power generation capacity and hydroelectric power generation demands in different prediction intervals, the power supply demand is considered, and early warning is pointedly issued.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power dispatching, and in particular to a method and system for early warning of low water levels in a hydropower plant based on power generation capacity trend assessment. Background Art

[0002] Hydropower is not only an important power source for grid dispatching and operation, but also an important flexible regulation resource for power operation. The provincial power grid low water warning is essentially a warning of the expected power generation and regulation capacity of all hydropower stations in the provincial power grid, which plays an important role in the evaluation of power supply. Compared with the hydropower plant low water warning, the provincial power grid low water warning is evaluated on the overall power generation capacity of all hydropower plants in the provincial power grid, while the hydropower plant low water warning is evaluated on a single hydropower plant.

[0003] Traditional grid hydropower plant low water warning only considers the expected water inflow level. Taking the current provincial grid low water warning of the Southern Power Grid as an example, the provincial grid low water warning is divided into three levels of yellow, orange and red according to the severity of the impact, from light to heavy. The judgment criteria are as follows:

[0004] Yellow warning, the judgment conditions include:

[0005] Taking the current hydropower storage of the provincial power grid plus the future predicted natural water inflow as the total amount, and calculating according to the average hydropower generation of the provincial power grid in the previous 10 days, the time it takes for all the reservoirs of major hydropower plants to drop to dead water level is less than 60 days; the average hydropower output of the provincial power grid in the previous 30 days (the planned hydropower power generation output obtained by the rolling adjustment plan of the reservoir from the current to the pre-flood season during the dry season, the same below) is less than one-third of the hydropower installed capacity.

[0006] Orange warning, the determination conditions include:

[0007] Taking the current hydropower storage of the provincial power grid plus the predicted natural water inflow in the future as the total amount, and calculating based on the average daily hydropower generation of the provincial (regional) power grid in the previous 10 days, it will take less than 30 days for the reservoirs of major hydropower plants to drop to dead water levels; the average hydropower inflow output of the provincial power grid in the previous 30 days was less than a quarter of the hydropower installed capacity.

[0008] Red alert, the judgment conditions include:

[0009] Taking the current hydropower storage of the provincial power grid plus the predicted natural water inflow in the future as the total amount, and calculating based on the average daily hydropower generation of the provincial power grid in the previous 10 days, it will take less than 10 days for the reservoirs of major hydropower plants to drop to dead water levels; the average hydropower inflow output of the provincial power grid in the previous 30 days was less than one-fifth of the hydropower installed capacity. Summary of the invention

[0010] In view of the above-mentioned problems, the present invention is proposed.

[0011] Therefore, the technical problem solved by the present invention is that the traditional method of predicting natural water inflow is not detailed enough, does not carefully consider the impact of power grid operation on hydropower generation demand, and does not fully consider the intrinsic relationship between low water and power supply.

[0012] To solve the above technical problems, the present invention provides the following technical solutions: a method for warning low water levels in hydropower plants based on power generation capacity trend assessment, comprising: collecting data of target hydropower plants, assessing the accuracy of water inflow forecasts, and dividing water inflow forecast intervals; assessing the hydropower generation demand interval, and calculating the trend of changes in hydropower energy storage and hydropower generation capacity based on the evaluation results of the generation demand interval; and issuing a low water level warning based on the trend of changes in hydropower generation capacity.

[0013] As a preferred solution of the method for low water level warning of hydropower plants based on power generation capacity trend assessment described in the present invention, the data of the target hydropower plant includes meteorological data, electricity demand forecast data, conventional power generation capacity data, hydropower operation characteristic data and historical data of the target data.

[0014] As a preferred solution of the method for early warning of low water flow in a hydropower plant based on the trend evaluation of power generation capacity described in the present invention, wherein: evaluating the accuracy of the water inflow prediction includes: the extended prediction accuracy of the water inflow on the dth day is defined as the mode of the extended prediction accuracy of the water inflow on the dth day of each operating day in history, expressed as:

[0015]

[0016] in, represents the extended prediction accuracy of water inflow on day d; It indicates the accuracy of water inflow forecast on the nd day and extended to the d day in historical data; represents the function of finding the mode; calculates the influence of water inflow forecast deviation, which is defined as the maximum water inflow deviation caused by the cumulative effect of water inflow extended forecast accuracy under the average water inflow level, expressed as:

[0017]

[0018] Among them, Q MA It represents the multi-year average daily water inflow during the forecast period; It indicates the deviation of water inflow forecast as of D day due to the cumulative effect of the accuracy of extended water inflow forecast.

[0019] As a preferred solution of the method for early warning of low water flow in hydropower plants based on power generation capacity trend assessment described in the present invention, the water inflow forecast interval includes, when the influence degree of water inflow forecast deviation does not exceed the limit value, the corresponding date range is the acceptable forecast interval, which is expressed as:

[0020]

[0021] Among them, ΔQ s Indicates the limit of influence of water inflow forecast deviation; It indicates the influence of the deviation of the water inflow forecast on the extended D day; It indicates the impact of the deviation of the water inflow forecast extending to day D+1.

[0022] As a preferred solution of the method for early warning of low water level in a hydropower plant based on the trend assessment of power generation capacity described in the present invention, the hydropower generation demand interval includes: the hydropower generation demand is obtained by deducting the power generation of conventional power sources and the power generation of new energy from the total power generation demand determined by the power demand, which is expressed as:

[0023]

[0024] in, It represents the hydropower generation demand on the operating day; Indicates the power generation of conventional power supply on the operating day; Indicates the amount of renewable energy power generated on the operating day; represents the electricity demand forecast for the operating day d; γ represents the system loss rate; the upper limit of hydropower demand is calculated, that is, the power demand when the power consumption reaches the maximum and the power generation of conventional power sources and renewable energy is reduced to the minimum; the lower limit of hydropower demand is calculated, that is, the power demand when the power consumption reaches the minimum and the power generation of conventional power sources and renewable energy reaches the maximum.

[0025] As a preferred solution of the method for early warning of low water level in a hydropower plant based on power generation capacity trend assessment described in the present invention, wherein: the change trend of the hydropower energy storage and hydropower generation capacity includes calculating the change interval of the hydropower energy storage on the operating day d, which is expressed as:

[0026]

[0027] in, Indicates initial energy storage; Even-numbered operating days d hydroelectric energy storage; It indicates the water inflow on the predicted operation day dd; It indicates the predicted hydropower demand on operation day dd. Considering the difference in the interval prediction of hydropower demand, the hydropower storage on operation day d is also an interval value, with upper and lower limits respectively:

[0028]

[0029] in, It indicates the upper limit of hydropower storage capacity on the operating day d; It represents the lower limit of hydropower energy storage on the operating day d. The maximum daily hydropower generation under different hydropower energy storage levels is obtained according to historical data statistics, which is used as the hydropower generation capacity.

[0030] As a preferred solution of the method for low water early warning of a hydropower plant based on power generation capacity trend assessment described in the present invention, the low water early warning includes issuing a red low water early warning when the water inflow in the acceptable prediction interval is lower than the average level, the upper limit of the hydropower energy storage shows a continuous downward trend, and the upper limit of the hydropower generation capacity does not meet the lower limit of the hydropower generation demand, which is expressed as:

[0031]

[0032] Among them, Q MA It represents the average daily water inflow during the forecast period; It represents the water inflow on the predicted operation day d; It indicates the upper limit of hydropower generation capacity on the operating day d; represents the lower limit of hydropower generation capacity on the operating day d; CFP represents the set of acceptable prediction intervals; when the water inflow in the acceptable prediction interval is lower than the average level, the lower limit of hydropower energy storage shows a continuous downward trend, and the difference between the lower limit of hydropower generation capacity and the upper limit of hydropower generation demand is less than the given limit, an orange low water warning is issued, which is expressed as:

[0033]

[0034] Among them, ΔE H Indicates a given limit; when the water inflow in the unacceptable forecast interval is lower than the average level, resulting in a continuous downward trend in both the upper and lower limits of hydropower storage, and the upper limit of hydropower generation capacity is lower than the lower limit of hydropower generation demand, a yellow low water warning is issued, which is expressed as:

[0035]

[0036] Among them, NCFP represents the set of unacceptable prediction intervals.

[0037] In the second aspect, the present invention also provides a low-water warning system for a hydropower plant based on the evaluation of power generation capacity trends, including: an acquisition module, which collects target data, evaluates the accuracy of water inflow prediction based on historical data of water inflow prediction accuracy, calculates the deviation of water inflow prediction, and divides the water inflow prediction interval; an evaluation module, which evaluates the hydropower generation demand interval, and calculates the upper and lower limits of the hydropower generation demand, and calculates the changing trends of hydropower energy storage and hydropower generation capacity based on the evaluation results of the generation demand interval; an early warning module, which issues low-water warnings in a differentiated manner according to the changing trend of hydropower generation capacity, taking into account the differences in prediction accuracy between acceptable prediction intervals and unacceptable prediction intervals, and considering the impact of hydropower generation capacity on power supply.

[0038] In a third aspect, the present invention further provides a computing device, comprising: a memory and a processor;

[0039] The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the hydropower plant low water early warning method based on power generation capacity trend assessment are implemented.

[0040] In a fourth aspect, the present invention further provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, can implement the steps of the method for low water level warning of a hydropower plant based on power generation capacity trend assessment.

[0041] Beneficial effects of the present invention: The method of the present invention divides the prediction interval into an acceptable prediction interval and an unacceptable prediction interval according to the accuracy of water inflow prediction, so as to solve the problem of the influence of prediction accuracy deviation on the early warning result. Considering the changes in electricity demand, conventional power sources such as coal-fired power, and new energy power generation capacity, a method for predicting the hydropower generation demand interval is proposed. Combined with the relationship between hydropower energy storage, hydropower generation capacity, and hydropower generation demand under different prediction intervals, considering the power supply demand, targeted early warnings are issued. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0043] Figure 1 An overall flow chart of a method for early warning of low water levels in a hydropower plant based on power generation capacity trend assessment provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0045] Example 1

[0046] Reference Figure 1 , which is an embodiment of the present invention, provides a method for early warning of low water level in a hydropower plant based on power generation capacity trend assessment, comprising:

[0047] S1: Collect data from the target hydropower plant, evaluate the accuracy of water inflow prediction, and divide the water inflow prediction interval.

[0048] The traditional provincial power grid hydropower plant low water early warning judgment standard is relatively simple, but there are the following problems:

[0049] First, the prediction of natural water inflow is not considered carefully enough. The prediction of natural water inflow is greatly affected by meteorological forecasts. As time goes by, the prediction accuracy will drop significantly. Traditional early warning methods do not carefully consider the impact of prediction accuracy on early warning results. When the prediction evaluation time is long, the prediction accuracy drops significantly, which will lead to a large deviation between the prediction results and the actual situation.

[0050] Second, the impact of grid operation on hydropower demand is not carefully considered. The traditional early warning method uses the average hydropower generation in the previous 10 days to assess the future hydropower demand. It does not carefully consider changes in electricity demand and the generation capacity of other power sources, which will affect the results of the hydropower demand assessment and lead to inaccurate assessment of hydropower storage changes.

[0051] Third, the inherent relationship between low water and power supply is not fully considered. The issuance of low water warnings is essentially to warn of power supply shortages caused by low water supply, but traditional methods do not consider the above inherent relationship. The following scenario may occur: a low water warning has been issued, but the power supply is not tight. This situation does not match the actual needs of power operation and may even cause interference.

[0052] To this end, a method for hydropower plant low water early warning based on power generation capacity trend assessment is proposed. According to the accuracy of water inflow forecast, the forecast interval is divided into acceptable forecast interval and unacceptable forecast interval to solve the problem of the impact of forecast accuracy deviation on early warning results. Considering the changes in electricity demand, conventional power sources such as coal-fired power, and new energy power generation capacity, a method for hydropower generation demand interval forecasting is proposed. Combined with the relationship between hydropower energy storage, hydropower generation capacity, and hydropower generation demand under different forecast intervals, considering the power supply demand, targeted early warnings are issued.

[0053] Furthermore, the data and data sources of the target hydropower plant include: (1) weather forecast, which mainly includes historical and future forecast data of weather information such as water inflow, sunshine, and wind, which comes from the weather forecast management system;

[0054] (2) Electricity demand forecast data, mainly including external power transmission and reception plans and provincial power grid power consumption forecasts, mainly from the power generation plan management system;

[0055] (3) Conventional power generation capacity data, mainly coal-fired power and other conventional power generation capacity, mainly from the power generation planning management system;

[0056] (4) Hydropower operation characteristic data, mainly the maximum hydropower generating capacity at different historical hydropower storage levels, mainly comes from the cascade hydropower optimization management system.

[0057] When collecting target data, it is necessary to collect historical data from past years, use historical data to evaluate the accuracy of water inflow forecasts, and compare recent data with data from the same period in previous years to better reflect the overall level of changes in water inflow and accurately issue low water warnings.

[0058] Furthermore, the accuracy of water inflow prediction is evaluated, and the prediction interval is divided. An evaluation index for the accuracy of extended water inflow prediction is proposed. Based on this index, the impact of water inflow prediction deviation is calculated. Under an acceptable level of prediction deviation impact, the prediction and warning time period is divided into multiple intervals.

[0059] The current water inflow forecasting technology can provide daily water inflow forecast data for the next 60 days or so. Limited by the accuracy of meteorological forecasts, the accuracy of water inflow forecasts tends to decrease as the date extends. Therefore, the characteristics of water inflow forecast accuracy changes are analyzed, and the impact of forecast deviation on warning results is divided into acceptable and unacceptable intervals.

[0060] Define and calculate the accuracy of the daily extended water inflow forecast. The accuracy of the extended water inflow forecast on the dth day is defined as the mode of the extended water inflow forecast accuracy on the dth day of each operating day in history. This indicator reflects the trend of the water inflow forecast accuracy with the extension date, which is expressed as:

[0061]

[0062] in, represents the extended prediction accuracy of water inflow on day d; It indicates the accuracy of water inflow forecast on the nd day and extended to the d day in historical data; Represents a function that finds the mode.

[0063] The influence of water inflow forecast deviation is calculated. The influence of water inflow forecast deviation is defined as the maximum water inflow deviation caused by the cumulative effect of water inflow extended forecast accuracy under the average water inflow level, which is expressed as:

[0064]

[0065] Among them, Q MA It represents the multi-year average daily water inflow during the forecast period; It indicates the deviation of water inflow forecast as of D day due to the cumulative effect of the accuracy of extended water inflow forecast.

[0066] When the impact of the water inflow forecast deviation does not exceed the limit, the corresponding date range is the acceptable forecast interval, and the date beyond this date to the date that can provide daily water inflow forecast data under the current technical level is the unacceptable forecast interval, which is expressed as:

[0067]

[0068] Among them, ΔQs Indicates the limit of influence of water inflow forecast deviation; It indicates the influence of the deviation of the water inflow forecast on the extended D day; It indicates the impact of the deviation of the water inflow forecast extending to day D+1.

[0069] If D-day meets the above requirements, then the period up to D-day is an acceptable forecast interval, and D+1 day and thereafter is an unacceptable interval.

[0070] S2: Evaluate the hydropower generation demand range, and calculate the changing trend of hydropower energy storage and hydropower generation capacity based on the evaluation results of the generation demand range.

[0071] Furthermore, the subsequent hydropower demand is evaluated based on the electricity demand and the forecast data of conventional power sources and renewable energy generation capacity. Different from the traditional method, which uses the actual hydropower generation in the previous 10 days as the standard for predicting future power generation demand, this method will use the interval prediction method based on the future changes in the power generation and consumption situation to evaluate the subsequent daily hydropower demand and obtain the interval prediction results of hydropower demand.

[0072] The demand for hydropower generation can be expressed as the total power generation demand determined by electricity demand minus the power generation of conventional power sources such as coal power and renewable energy, which can be expressed as:

[0073]

[0074] in, It represents the hydropower generation demand on the operating day; Indicates the power generation of conventional power supply on the operating day; Indicates the amount of renewable energy power generated on the operating day; represents the electricity demand forecast on the operating day d; γ represents the system loss rate.

[0075] It can be seen that changes in electricity demand, coal-fired power generation, and renewable energy power generation will affect the demand for hydropower generation. Specifically:

[0076] (1) The increase in electricity demand and the decrease in coal-fired power generation and renewable energy power generation will lead to an increase in demand for hydropower generation;

[0077] (2) The decrease in electricity demand and the increase in coal-fired power generation and renewable energy power generation will lead to a decrease in the demand for hydropower generation.

[0078] Based on this, the interval forecasting method is adopted to consider the above three factors and their combined scenarios to obtain the upper and lower limits of the hydropower generation demand forecast.

[0079] Calculating the upper limit of hydropower generation demand When the power consumption reaches the maximum The power generation capacity of conventional power sources and renewable energy sources is reduced to the minimum power generation capacity requirement, which is expressed as:

[0080]

[0081] in, Indicates the lower limit of conventional power generation on the operating day; Indicates the lower limit of renewable energy power generation on the operating day.

[0082] Calculating the minimum hydropower generation demand Minimize power consumption The power generation of conventional power sources and new energy sources reaches the maximum power generation demand, which is expressed as:

[0083]

[0084] in, Indicates the upper limit of conventional power generation on the operating day; Indicates the upper limit of renewable energy power generation on the operating day.

[0085] Furthermore, based on the prediction results of the power generation demand interval, the trend of hydropower storage and power generation capacity is evaluated, and the change interval of hydropower storage on the operating day d is calculated, which can be expressed as the sum of the current hydropower storage and the change under the influence of daily water inflow and power generation demand:

[0086]

[0087] in, Indicates initial energy storage; Even-numbered operating days d hydroelectric energy storage; It indicates the water inflow on the predicted operation day dd; Represents the forecasted hydropower generation demand on operating day dd.

[0088] It should be noted that the inflow is the amount of water entering the reservoir. If the inflow is higher than the power generation demand, the amount of water in the reservoir increases, otherwise it decreases. The hydropower generation demand is the amount of water that needs to be released from the reservoir to meet the power demand. The higher the power generation demand, the more the water in the reservoir decreases. The difference between the inflow and the hydropower generation demand reflects the net change in water storage.

[0089] Taking into account the difference in the forecast interval of hydropower generation demand, the hydropower energy storage on the operation day d is also an interval value, with upper and lower limits respectively:

[0090]

[0091] in, It indicates the upper limit of hydropower storage capacity on the operating day d; Indicates the lower limit of hydropower energy storage on the operating day.

[0092] Calculate the change of hydropower generation capacity on the operating day d. According to historical data, the maximum daily hydropower generation under different hydropower storage levels can be obtained, that is, the hydropower generation capacity. The upper and lower limits of the hydropower generation capacity on the operating day d are:

[0093]

[0094] in, It indicates the upper limit of hydropower generation capacity on the operating day d; represents the lower limit of hydropower generation capacity on the operating day d; HQ represents the hydropower generation capacity function under different hydropower storage levels obtained from historical data statistics.

[0095] S3: Issue low water warnings based on changing trends in hydropower generation capacity.

[0096] Furthermore, based on the changing trend of hydropower generation capacity, taking into account the differences in prediction accuracy between acceptable prediction intervals and unacceptable prediction intervals, and considering the impact of hydropower generation capacity on power supply, differentiated warnings are issued.

[0097] When the water inflow within the acceptable forecast interval is lower than the average level, the upper limit of hydropower storage capacity shows a continuous downward trend, and the upper limit of hydropower generation capacity does not meet the lower limit of hydropower generation demand, a red low water warning is issued, which is expressed as:

[0098]

[0099] Among them, CFP represents the set of acceptable forecast intervals; in this case, the tight electricity supply situation is in an emergency state, and conventional power sources such as coal-fired power have reached their maximum power generation capacity, and will face load management and other measures.

[0100] When the water inflow within the acceptable forecast interval is lower than the average level, the lower limit of hydropower storage shows a continuous downward trend, and the difference between the lower limit of hydropower generation capacity and the upper limit of hydropower generation demand is less than a given limit, an orange low water warning is issued, which is expressed as:

[0101]

[0102] Among them, ΔE H It indicates a given limit, which is generally the maximum daily power generation of the largest coal-fired power unit, in order to cope with possible operational fault deviations. In this case, the power supply tension is in a more urgent state, and the power generation level of conventional power sources such as coal-fired power must be increased immediately, otherwise load management and other measures will be faced.

[0103] When the water inflow in the unacceptable forecast interval is lower than the average level, resulting in a continuous downward trend in both the upper and lower limits of hydropower storage, and the upper limit of hydropower generation capacity is lower than the lower limit of hydropower generation demand, a yellow low water warning is issued, which is expressed as:

[0104]

[0105] Among them, NCFP stands for unacceptable forecast interval set; in this case, the power supply in the foreseeable range may face a tense situation due to the shortage of hydropower water, which requires real-time tracking and continuous optimization of power generation arrangements.

[0106] The present embodiment also provides a low-water early warning system for a hydropower plant based on the evaluation of power generation capacity trends, including: a collection module for collecting target data, evaluating the accuracy of water inflow prediction based on historical data of water inflow prediction accuracy, calculating the deviation of water inflow prediction, and dividing the water inflow prediction interval; an evaluation module for evaluating the hydropower generation demand interval, and calculating the upper and lower limits of the hydropower generation demand, and calculating the changing trends of hydropower energy storage and hydropower generation capacity based on the evaluation results of the generation demand interval; and an early warning module for issuing differentiated low-water early warnings based on the changing trend of hydropower generation capacity, taking into account the differences in prediction accuracy between acceptable prediction intervals and unacceptable prediction intervals, and taking into account the impact of hydropower generation capacity on power supply.

[0107] This embodiment also provides a computing device, including a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement the low water warning method for a hydropower plant based on power generation capacity trend assessment as proposed in the above embodiment.

[0108] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for early warning of low water level in a hydropower plant based on the evaluation of power generation capacity trend as proposed in the above embodiment is implemented.

[0109] The storage medium proposed in this embodiment and the low water warning method for a hydropower plant based on power generation capacity trend assessment proposed in the above embodiment belong to the same inventive concept. The technical details not described in detail in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0110] Through the above description of the implementation method, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (RandomAccessMemory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0111] Example 2

[0112] The following is an embodiment of the present invention, which provides a method for early warning of low water levels in a hydropower plant based on power generation capacity trend assessment. In order to verify the beneficial effects of the present invention, a scientific demonstration is carried out through simulation experiments.

[0113] Data from a hydropower plant was collected, and meteorological data for the past three years and the next 60 days were obtained through the meteorological forecast management system, including information such as water inflow, sunshine, and wind speed. At the same time, the power demand forecast data for the next 60 days and the power generation capacity data of conventional power sources (mainly coal-fired power) were obtained from the power generation plan management system. The historical power generation capacity data of different hydropower stations in the province at different energy storage levels were obtained through the cascade hydropower optimization management system.

[0114] The historical water inflow forecast data were statistically analyzed to calculate the accuracy of the daily water inflow extended forecast. Based on these data, the impact of water inflow forecast deviation was defined and calculated, and multiple intervals of the forecast and warning time period were divided.

[0115] In order to prove the accuracy of the present invention in low water early warning, five days of data in the acceptable prediction interval are selected for display and calculation. Considering the simplicity of calculation and display, the initial energy storage is set to 10000m 3 , other data are displayed in integer form, and the collected raw data are shown in the following table.

[0116] Table 1 Original data table

[0117]

[0118] According to the method of the present invention, the changing trends of hydropower storage and hydropower generation capacity are calculated, and the low water warning situation is analyzed. The detailed data are shown in the following table.

[0119] Table 2 Warning details data table

[0120]

[0121] It can be seen from the data in the table that hydropower storage will show a downward trend in the next five days. This is because the daily water inflow is lower than the hydropower generation demand, which makes the hydropower storage decrease day by day. At the same time, the upper and lower limits of hydropower generation capacity are very close. Therefore, an orange low water warning is issued according to the conditions.

[0122] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for early warning of low water flow in a hydropower plant based on power generation capacity trend assessment, characterized in that: include: Collect data from the target hydropower plant, evaluate the accuracy of water inflow forecast, and divide the water inflow forecast interval; Assess the hydropower generation demand range, and calculate the change trend of hydropower energy storage and hydropower generation capacity based on the generation demand range assessment results; Issue low water warnings based on changing trends in hydropower generation capacity.

2. The method for early warning of low water level in a hydropower plant based on power generation capacity trend assessment according to claim 1, characterized in that: The data of the target hydropower plant include meteorological data, electricity demand forecast data, conventional power generation capacity data, hydropower operation characteristic data and historical data of the target data.

3. The method for early warning of low water level in a hydropower plant based on power generation capacity trend assessment according to claim 2, characterized in that: The evaluation of the water inflow prediction accuracy includes that the extended prediction accuracy of the water inflow on the dth day is defined as the mode of the extended d-day water inflow prediction accuracy of each operating day in history, expressed as: in, represents the extended prediction accuracy of water inflow on the dth day; It indicates the accuracy of water inflow forecast on the nd day and extended to the d day in historical data; represents the function of finding the mode; The influence of water inflow forecast deviation is calculated. The influence of water inflow forecast deviation is defined as the maximum water inflow deviation caused by the cumulative effect of water inflow extended forecast accuracy under the average water inflow level, which is expressed as: Among them, Q MA It represents the multi-year average daily water inflow during the forecast period; It indicates the deviation of water inflow forecast as of D day due to the cumulative effect of the accuracy of extended water inflow forecast.

4. The method for early warning of low water level in a hydropower plant based on power generation capacity trend assessment according to claim 3, characterized in that: The water inflow forecast interval includes, when the water inflow forecast deviation impact does not exceed the limit, the corresponding date range is the acceptable forecast interval, expressed as: Among them, ΔQ s Indicates the limit of influence of water inflow forecast deviation; It indicates the influence of the deviation of the water inflow forecast on the extended D day; It indicates the impact of the deviation of the water inflow forecast extending to day D+1.

5. The method for early warning of low water level in a hydropower plant based on power generation capacity trend assessment according to claim 4, characterized in that: The hydropower generation demand range includes: the hydropower generation demand is obtained by deducting the conventional power generation and the new energy generation from the total power generation demand determined by the electricity demand, which is expressed as: in, It represents the hydropower generation demand on the operating day; Indicates the power generation of conventional power supply on the operating day; Indicates the amount of renewable energy power generated on the operating day; represents the power demand forecast for the operation day d; γ represents the system loss rate; Calculate the upper limit of hydropower demand, that is, the power generation demand when power consumption reaches the maximum and the power generation of conventional power sources and renewable energy sources is reduced to the minimum; Calculate the lower limit of hydropower generation demand, that is, the power consumption reaches the minimum, the power generation of conventional power sources and the power generation of new energy reach the maximum power generation demand.

6. The method for early warning of low water level in a hydropower plant based on power generation capacity trend assessment according to claim 5, characterized in that: The hydropower storage and hydropower generation capacity change trend includes calculating the hydropower storage change interval on the operation day d, which is expressed as: in, Indicates initial energy storage; Even-numbered operating days d hydroelectric energy storage; It indicates the water inflow on the predicted operation day dd; It represents the hydropower generation demand on the forecasted operation day dd; Taking into account the difference in the forecast interval of hydropower generation demand, the hydropower energy storage on the operation day d is also an interval value, with upper and lower limits respectively: in, It indicates the upper limit of hydropower storage capacity on the operating day d; Indicates the lower limit of hydropower storage on the operating day d; According to historical data statistics, the maximum daily hydropower generation under different hydropower storage levels is obtained as the hydropower generation capacity.

7. The method for early warning of low water level in a hydropower plant based on power generation capacity trend assessment according to claim 6, characterized in that: The low water warning includes issuing a red low water warning when the water inflow within the acceptable forecast interval is lower than the average level, the upper limit of hydropower energy storage shows a continuous downward trend, and the upper limit of hydropower generation capacity does not meet the lower limit of hydropower generation demand, which is expressed as: Among them, Q MA It represents the average daily water inflow during the forecast period; It represents the water inflow on the predicted operation day d; It indicates the upper limit of hydropower generation capacity on the operating day d; represents the lower limit of hydropower generation capacity on the operating day d; CFP represents the set of acceptable prediction intervals; When the water inflow within the acceptable forecast interval is lower than the average level, the lower limit of hydropower storage shows a continuous downward trend, and the difference between the lower limit of hydropower generation capacity and the upper limit of hydropower generation demand is less than a given limit, an orange low water warning is issued, which is expressed as: Where, ΔE H Indicates a given limit; When the water inflow in the unacceptable forecast interval is lower than the average level, resulting in a continuous downward trend in both the upper and lower limits of hydropower storage, and the upper limit of hydropower generation capacity is lower than the lower limit of hydropower generation demand, a yellow low water warning is issued, which is expressed as: Among them, NCFP represents the set of unacceptable prediction intervals.

8. A low water early warning system for a hydropower plant based on power generation capacity trend assessment using the method as claimed in any one of claims 1 to 7, characterized in that: include, The acquisition module collects target data, evaluates the accuracy of water inflow prediction based on historical data of water inflow prediction accuracy, calculates the deviation of water inflow prediction, and divides the water inflow prediction interval; An evaluation module evaluates the hydropower generation demand range and calculates the upper and lower limits of the hydropower generation demand. Based on the evaluation results of the generation demand range, it calculates the change trend of hydropower energy storage and hydropower generation capacity. The early warning module issues differentiated low water warnings based on the changing trend of hydropower generation capacity, taking into account the differences in prediction accuracy between acceptable and unacceptable prediction intervals, and the impact of hydropower generation capacity on power supply.

9. A computing device comprising: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the method described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions, when executed by a processor, implement the steps of the method according to any one of claims 1 to 7.

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