Unit economic operation method and system based on reservoir drought limit water level control

Abstract

The unit economic operation method and system based on the control of the drought limit water level of a reservoir provided by this application. The method includes the following steps: calculating and obtaining the phased drought limit water levels of the reservoir by using the hourly sliding calculation method respectively; based on the phased drought limit water levels of the reservoir, constructing a unit economic operation model with maximizing the total power generation of the reservoir within the planned period as the objective function and satisfying the physical constraint conditions of the reservoir - hydropower station - unit; based on the constructed unit economic operation model, using the locust optimization algorithm to seek the optimal economic operation strategy of each working unit under the optimal criterion of power generation. This application builds a framework based on "drought limit water level control - unit economic operation - intelligent optimization", constructs and efficiently solves a general model for unit economic operation based on the control of the drought limit water level of the reservoir, and proposes a unit economic operation method based on the control of the drought limit water level of the reservoir, which can provide a theoretical basis and technical support for the scientific formulation of the unit economic operation plan under the phased control of the drought limit water level of the basin reservoir.

Description

Technical Field

[0001] This application relates to the technical field of reservoir operation scheduling, and specifically to a method and system for the economic operation of units based on the control of the drought limit water level of the reservoir. Background Technique

[0002] The drought limit water level of a reservoir is the water level at which the reservoir remains persistently low and the flow rate remains persistently low, affecting the water use safety of urban and rural life, industrial and agricultural production, ecological environment, etc. It is the water level or flow rate at which drought resistance measures should be taken.

[0003] The phased control of the drought limit water level of a reservoir refers to the process of guiding the regulation of water conservancy benefits, ecological environment, etc. of the reservoir according to the scientifically demonstrated phased drought limit water level on the premise of ensuring the water use safety of urban and rural life, industrial and agricultural production, ecological environment, etc. during the reservoir drawdown period, considering the phased dry season and the scenario of relatively dry water. It is one of the effective methods to improve the utilization level of basin water resources and the water supply guarantee ability. The theory and method of the phased control of the drought limit water level of a reservoir are mainly divided into the monthly sliding calculation method, decision analysis method, multi-objective optimization method, etc. according to its mathematical principles. These methods all take the reservoir or hydropower station as a whole to develop the phased control technology of the drought limit water level, and have not yet involved the method for the economic operation of units based on the control of the drought limit water level of the reservoir.

[0004] Compared with the hydropower station operation scheduling under the phased control of the drought limit water level of the reservoir, the technical difficulties and challenges of the economic operation of units based on the control of the drought limit water level of the reservoir are reflected in:

[0005] The calculation granularity is finer. It is necessary to not only determine the optimal output of the hydropower station, but also determine the number of operating units, the combination, and the output of each operating unit.

[0006] The model complexity is higher. It is necessary to not only develop the phased control technology of the drought limit water level of the reservoir based on water supply safety, but also develop the technology for the economic operation of units under the control of the total water use.

[0007] The existing technology mainly focuses on the reservoir or hydropower station for the phased control object of the drought limit water level of the reservoir, and has not yet carried out research on the economic operation of units based on the control of the drought limit water level of the reservoir. Summary of the Invention

[0008] This application provides a method and system for the economic operation of units based on the control of the drought limit water level of the reservoir, which can solve the technical problems of finer calculation granularity and higher model complexity existing in the technical difficulties and challenges of the economic operation of units based on the control of the drought limit water level of the reservoir in the prior art.

[0009] In the first aspect, this application provides a method for the economic operation of units based on the control of the drought limit water level of the reservoir, including the following steps:

[0010] During each stage of the dry season of the reservoir, the phased drought limit water level of the reservoir is calculated and obtained respectively by using the hourly sliding calculation method.

[0011] Based on the phased drought-limited water levels of the reservoir, an economic operation model of the units is constructed with the objective of maximizing the total power generation of the reservoir during the planning period and satisfying the physical constraint conditions of the reservoir - hydropower station - units.

[0012] Based on the constructed economic operation model of the units, the locust optimization algorithm is used to seek the optimal economic operation strategy of the working units in each time period under the optimal criterion of power generation.

[0013] Combined with the first aspect, in one implementation, during each phase of the dry season of the reservoir, the phased drought-limited water levels of the reservoir are calculated respectively by using the step-by-step sliding calculation method, which specifically includes the following steps:

[0014] Following the principle of "summation for non-combinable water intakes and maximum value for combinable water intakes", the water consumption of the reservoir during the dry season is deduced.

[0015] According to the deduced water consumption of the reservoir during the dry season, the water supply that the reservoir should provide in the extremely dry water scenario is calculated by using the step-by-step sliding calculation method.

[0016] Combined with the reservoir water level corresponding to the maximum value of the sum of the water supply that the reservoir should provide in the extremely dry scenario and the dead storage capacity, as well as the elevation of the reservoir water intake implementation, the value of the phased drought-limited water level is determined.

[0017] Combined with the first aspect, in one implementation, the principle of "summation for non-combinable water intakes and maximum value for combinable water intakes" is followed to deduce the water consumption of the reservoir during the dry season as shown in the following formula:

[0018]

[0019] In the formula: W D (t) is the water consumption of the reservoir at time t; and are the water consumption above the dam and the water consumption below the dam at time t respectively; W GS (t) is the water supply above the dam at time t; W FD (t), W GG (t) and W HS (t) are the water consumption for power generation below the dam, the water consumption for irrigation, and the water consumption for environmental ecology at time t respectively.

[0020] Combined with the first aspect, in one implementation, according to the deduced water consumption of the reservoir during the dry season, the water supply that the reservoir should provide in the extremely dry water scenario is calculated by using the step-by-step sliding calculation method as shown in the following formula:

[0021]

[0022] In the formula: W Y (t) is the water supply that the reservoir should provide at time t.

[0023] Combined with the first aspect, in one embodiment, the phased drought limit water level value is determined by combining the reservoir water level corresponding to the maximum value of the sum of the water supply volume that the reservoir should supply and the dead storage capacity under the extremely dry scenario, and the elevation of the reservoir water intake implementation, as shown in the following formula:

[0024]

[0025] In the formula: is the water supply volume that the reservoir should supply in the i-th phased t time period; W i max is the maximum value of the sum of the water supply volume that the reservoir should supply in the i-th phased and the dead storage capacity; is the reservoir water level corresponding to the maximum value of the sum of the water supply volume that the reservoir should supply in the i-th phased and the dead storage capacity; Z QS is the elevation of the reservoir water intake facility; is the drought limit water level of the reservoir in the i-th phased.

[0026] Combined with the first aspect, in one embodiment, the objective function is as shown in the following formula:

[0027]

[0028] In the formula: T is the planning period; E(T) is the total power generation of the reservoir during the planning period, U(t) is the number of units that can be put into operation at the t-th moment, less than or equal to the total number of units; w is the number of the unit put into operation, less than or equal to U(t); g = L(t, w) is the in-plant number corresponding to the w-th unit that can be put into operation at the t-th moment; N g (t) is the output of the g-th unit in the plant.

[0029] Combined with the first aspect, in one embodiment, the physical constraint conditions of the reservoir - hydropower station - unit specifically include total water volume constraint, water volume balance constraint between the reservoir and the hydropower station, reservoir water level constraint, unit head constraint, unit output limit, unit water consumption characteristics, total output limit of the hydropower station, comprehensive utilization constraint, and initial reservoir water level constraint; among them, the initial reservoir water level is equal to the water level at the end of the reservoir impoundment period and is a known value.

[0030] Combined with the first aspect, in one embodiment, based on the constructed unit economic operation model, the locust optimization algorithm is used to seek the optimal economic operation strategy of the working units in each time period under the optimal power generation criterion, which specifically includes the following steps:

[0031] Set the locust algorithm parameters and initialize the population;

[0032] Evaluate the fitness of the initialized population to generate the offspring locust population;

[0033] Based on the constructed unit economic operation model, simulate the unit economic operation process and satisfy the physical constraints of the reservoir - hydropower station - unit, and perform iterative optimization on the generated offspring locust population;

[0034] Obtain the iteration termination situation of the offspring locust population according to the current iteration times. When the iteration terminates, output the optimal economic operation strategy of the working units in each period under the optimal criterion of power generation.

[0035] In a second aspect, the present application provides a unit economic operation system based on reservoir drought limit water level control, including:

[0036] A stage drought limit water level acquisition module, which is used to calculate and obtain the stage drought limit water level of the reservoir respectively by using the hourly sliding calculation method during each stage of the reservoir's dry season;

[0037] A unit economic operation model construction module, which is communicatively connected to the stage drought limit water level acquisition module, and is used to construct a unit economic operation model with maximizing the total power generation of the reservoir during the planned period as the objective function and satisfying the physical constraint conditions of the reservoir - hydropower station - unit based on the stage drought limit water level of the reservoir;

[0038] An optimal economic operation strategy acquisition module, which is communicatively connected to the unit economic operation model construction module, and is used to seek the optimal economic operation strategy of the working units in each period under the optimal criterion of power generation by using the locust optimization algorithm based on the constructed unit economic operation model.

[0039] Combined with the second aspect, in an implementation manner, the stage drought limit water level acquisition module includes:

[0040] A reservoir dry season water consumption acquisition unit, which is used to deduce the water consumption of the reservoir during the dry season by following the principle of "summing up when water intake cannot be combined and taking the maximum value when water intake can be combined";

[0041] A reservoir water supply amount acquisition unit, which is communicatively connected to the reservoir dry season water consumption acquisition unit, and is used to calculate the water supply amount that the reservoir should supply under the extremely dry water scenario by using the hourly sliding calculation method according to the deduced water consumption of the reservoir during the dry season;

[0042] A stage drought limit water level value acquisition unit, which is communicatively connected to the reservoir water supply amount acquisition unit, and is used to determine the stage drought limit water level value by combining the reservoir water level corresponding to the maximum value of the sum of the water supply amount that the reservoir should supply under the extremely dry scenario and the dead storage capacity and the elevation of the reservoir water intake implementation.

[0043] The beneficial effects brought by the technical solution provided by the embodiments of the present application at least include:

[0044] The present application builds a framework based on "drought limit water level control - unit economic operation - intelligent optimization", constructs and efficiently solves a general model for unit economic operation based on reservoir drought limit water level control, and proposes a method for unit economic operation based on reservoir drought limit water level control;

[0045] This application not only provides a technology for the phased control of the drought-limited water level of reservoirs based on water supply security, but also provides a method for the economic operation of units under the control of the total water consumption, which can provide a theoretical basis and technical support for the scientific formulation of the economic operation plan of units under the phased control of the drought-limited water level of basin reservoirs;

[0046] The method for the economic operation of units based on the control of the drought-limited water level of reservoirs proposed in this application has a finer calculation granularity. It not only determines the optimal output of the hydropower station, but also determines the number of operating units, the combination, and the output of each operating unit. Description of the Drawings

[0047] Figure 1 It is the flowchart of the method for the economic operation of units based on the control of the drought-limited water level of reservoirs provided by the embodiment of this application;

[0048] Figure 2 It is another flowchart of the method for the economic operation of units based on the control of the drought-limited water level of reservoirs provided by the embodiment of this application;

[0049] Figure 3 It is the phased control diagram of the drought-limited water level of the Three Gorges Reservoir provided by the embodiment of this application;

[0050] Figure 4 It is the control scheme of the drought-limited water level of the Three Gorges Reservoir provided by the embodiment of this application;

[0051] Figure 5 It is the iterative process of the locust algorithm for the economic operation of the units of the Three Gorges Hydropower Station provided by the embodiment of this application. Detailed Embodiments

[0052] In order to enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

[0053] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices. The descriptions of terms such as "first", "second", and "third" are used to distinguish different objects, etc., and do not represent a sequential order, nor do they limit that "first", "second", and "third" are of different types.

[0054] In the description of the embodiments of the present application, words such as "exemplary", "for example", or "for illustration" are used to represent examples, illustrations, or explanations. Any embodiment or design solution described as "exemplary", "for example", or "for illustration" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary", "for example", or "for illustration" is intended to present relevant concepts in a specific manner.

[0055] In the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B may mean A or B; "and / or" in the text is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality of" means two or more than two.

[0056] In some processes described in the embodiments of the present application, there are multiple operations or steps that appear in a specific order. However, it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or may be executed in parallel. The serial numbers of the operations are only used to distinguish different operations, and the serial numbers themselves do not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in order or in parallel, and these operations or steps may be combined.

[0057] To make the objectives, technical solutions, and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the accompanying drawings.

[0058] In a first aspect, please refer to Figure 1 - Figure 2 , the embodiments of the present application provide a method for the economic operation of units based on the control of the drought limit water level of a reservoir, including the following steps:

[0059] Step S1: In each sub-period of the dry season of the reservoir, the sliding calculation method by time period is respectively used to calculate and obtain the sub-period drought limit water level of the reservoir;

[0060] Step S2: Based on the sub-period drought limit water level of the reservoir, an economic operation model of the unit is constructed with the objective of maximizing the total power generation of the reservoir during the planning period and satisfying the physical constraint conditions of the reservoir - hydropower station - unit;

[0061] Step S3: Based on the constructed economic operation model of the unit, the locust optimization algorithm is used to seek the optimal economic operation strategy of the working units in each time period under the optimal criterion of power generation.

[0062] This application constructs a framework based on "dry limit water level control - unit economic operation - intelligent optimization", constructs a general model for efficiently solving the economic operation of units based on the dry limit water level control of reservoirs, and proposes a method for the economic operation of units based on the dry limit water level control of reservoirs;

[0063] This application not only provides a technology for staged control of the dry limit water level of reservoirs based on water supply security, but also provides a method for the economic operation of units under the control of the total water consumption, which can provide a theoretical basis and technical support for the scientific formulation of the economic operation plan of units under the staged control of the dry limit water level of basin reservoirs;

[0064] The method for the economic operation of units based on the dry limit water level control of reservoirs proposed in this application has a finer calculation granularity. It not only determines the optimal output of the hydropower station, but also determines the number of operating units, combinations, and the output of each operating unit.

[0065] In this application, the unit is a water level control equipment unit with the reservoir or hydropower station as a whole.

[0066] In one embodiment, step S1: During each stage of the dry season of the reservoir, the staged dry limit water level of the reservoir is calculated respectively by using the step-by-step sliding calculation method, which specifically includes the following steps:

[0067] Step S11: Follow the principle of "summation for non-combinable water intake and maximum value for combinable water intake" to derive the water consumption during the dry season of the reservoir;

[0068] Step S12: According to the derived water consumption during the dry season of the reservoir, use the step-by-step sliding calculation method to calculate the water supply that the reservoir should provide in the extremely dry water scenario;

[0069] Step S13: Combine the water supply that the reservoir should provide in the extremely dry scenario with the maximum value of the sum of the dead storage capacity, and determine the staged dry limit water level value based on the reservoir water level and the elevation of the reservoir water intake implementation, as Figure 3 shown.

[0070] Based on step S1, the staged dry limit water level of the reservoir is calculated by using the step-by-step sliding calculation method, which provides a theoretical basis for improving the drought resistance dispatching ability of the reservoir, effectively guarantees water supply security, provides a water consumption constraint for the economic operation of units, and realizes the economic operation of the water supply units of the reservoir on this premise.

[0071] In one embodiment, as Figure 4 shown, based on the staged dry limit water level of the reservoir, the staged control of the dry limit water level of the reservoir is realized. The reservoir will orderly implement the drawdown operation between the staged dry limit water level (lower limit) and the normal storage water level (upper limit), and use the proposed staged control scheme of the dry limit water level of the reservoir for the drawdown operation to obtain the water storage and release process of the reservoir under different incoming water scenarios (design frequency ≥ 75%).

[0072] In one embodiment, if the reservoir mainly undertakes water supply tasks such as urban water supply, agricultural irrigation, environmental ecology, and power generation, where the water supply is diverted from upstream of the reservoir by gravity, agricultural irrigation utilizes the tail water of power generation, and environmental ecology is the water use within the river downstream of the reservoir dam. Following the principle of "summing up when water intake cannot be combined and taking the maximum value when water intake can be combined", the step S11: Following the principle of "summing up when water intake cannot be combined and taking the maximum value when water intake can be combined", the water consumption of the reservoir during the dry season is calculated as shown in the following formula:

[0073]

[0074] In the formula: tW D (t) is the water consumption of the reservoir at time t; and are the water consumption above the dam and below the dam at time t respectively; W GS (t) is the water supply above the dam at time t; W FD (t), W GG (v) and W HS (t) are the power generation water consumption, irrigation water consumption, and environmental ecology water consumption below the dam at time t respectively.

[0075] In one embodiment, considering the water inflow in the scenario of relatively dry years of the reservoir (design frequency ≥ 75%), the water supply that should be provided in each period of the reservoir is the difference between the water consumption in the period and the water inflow. Based on the calculated water consumption of the reservoir during the dry season, the water supply that should be provided in the reservoir under the extremely dry water scenario is calculated using the sliding calculation method for each period as shown in the following formula:

[0076]

[0077] In the formula: W Y (t) is the water supply that should be provided in the reservoir at time t.

[0078] In one embodiment, if the dry season of the reservoir is divided into n sub - periods, then within each sub - period, taking the reservoir water level corresponding to the maximum value of the sum of the water supply that should be provided in the reservoir calculated using the sliding calculation method for each period and the dead storage capacity as the basis, and considering factors such as the elevation of water intake implementation of the reservoir, comprehensively analyzing and combining the reservoir water level corresponding to the maximum value of the sum of the water supply that should be provided in the reservoir under the extremely dry scenario and the dead storage capacity and the elevation of water intake implementation of the reservoir, the value of the limited dry - season water level for each sub - period is determined. The value of the limited dry - season water level for each sub - period is determined as shown in the following formula:

[0079]

[0080]

[0081] In the formula: is the water supply that should be provided in the reservoir at time t of the i - th sub - period; Wi max It is the maximum value of the sum of the water supply volume that should be provided by the reservoir in the i-th stage and the dead storage capacity; It is the reservoir water level corresponding to the maximum value of the sum of the water supply volume that should be provided by the reservoir in the i-th stage and the dead storage capacity; Z QS It is the elevation of the reservoir water intake facility; It is the drought limit water level of the reservoir in the i-th stage.

[0082] In one embodiment, step S2: Based on the drought limit water levels of different stages of the reservoir, construct a unit economic operation model with maximizing the total power generation of the reservoir during the planning period as the objective function and satisfying the physical constraints of the reservoir - hydropower station - unit, which specifically includes the following steps:

[0083] Step S21: Establish an objective function with maximizing the total power generation of the reservoir during the planning period as the optimization objective;

[0084] Step S22: Obtain the physical constraints of the reservoir - hydropower station - unit. The physical constraints of the reservoir - hydropower station - unit include total water volume constraint, water balance constraint between the reservoir and the hydropower station, reservoir water level constraint, unit head constraint, unit output limit, unit water consumption characteristics, total output limit of the hydropower station, comprehensive utilization constraint, and initial reservoir water level constraint; among them, the initial reservoir water level is equal to the water level at the end of the reservoir impoundment period and is a known value.

[0085] In one embodiment, the objective function in step S21 with maximizing the total power generation of the reservoir during the planning period as the optimization objective is shown as the following formula:

[0086]

[0087] In the formula: T is the planning period; E(T) is the total power generation of the reservoir during the planning period, U(t) is the number of units that can be put into operation at the t-th moment, which is less than or equal to the total number of units; w is the number of the unit put into operation, which is less than or equal to U(t); g = L(t, w) is the in-plant number corresponding to the w-th unit that can be put into operation at the t-th moment; N g (t) is the output of the g-th unit in the plant.

[0088] In one embodiment, each of the physical constraints of the reservoir - hydropower station - unit in step S22 is shown as the following:

[0089] A: The total water volume constraint is shown as the following formula:

[0090]

[0091] In the formula: Q fd (t) is the power generation flow of the hydropower station at the t-th moment; Q qs (t) is the water abandonment volume of the reservoir at the t-th moment; It is the power generation flow of the g-th unit at the t-th moment; Wck (T) is the total reservoir discharge during the planning period T, which is calculated according to the water release process of the reservoir implementing the phased control of the drought-limited water level during the planning period in Step 1.

[0092] B: The water balance constraint of the reservoir hydropower station is shown as follows:

[0093]

[0094] C: The reservoir water level constraint is shown as follows:

[0095] Z min (t) ≤ Z(t) ≤ Z max (t)

[0096] Where: Z(t) is the reservoir water level at the t-th moment; Z min (t) and Z max (t) are the allowable minimum and maximum reservoir levels at the t-th moment respectively. Here, the allowable minimum reservoir level is the phased drought-limited water level of the reservoir, and the allowable maximum reservoir level is the normal reservoir level of the reservoir.

[0097] D: The unit head constraint is shown as follows:

[0098]

[0099] Where: H g (t) is the net head of the g-th unit at the t-th moment; and are the minimum and maximum heads of the g-th unit respectively; Z xy (t) is the downstream water level of the unit at the t-th moment; ΔH g (t) is the head loss of the g-th unit at the t-th moment; φ g (·) is the head loss function of the g-th unit.

[0100] E: The unit output limit is shown as follows:

[0101]

[0102] Where: and are the minimum and maximum outputs of the g-th unit at the t-th moment respectively.

[0103] F: The water consumption characteristics of the unit are shown as follows:

[0104]

[0105] Where: ψ g (·,·) is the water consumption characteristic curve of the g-th unit, which reflects the relationship between the unit power generation flow rate, unit output and head.

[0106] G: The total output limit of the hydropower station is shown by the following formula:

[0107]

[0108] Where: N(t) is the output of the hydropower station at the t-th moment; N min (t) and N max (t) are the minimum and maximum outputs of the hydropower station at the t-th moment respectively.

[0109] H: The comprehensive utilization constraint is shown by the following formula:

[0110]

[0111] Where: is the minimum discharge required for downstream comprehensive utilization, and the minimum discharge is determined by comprehensively considering the needs of ecology, water supply, shipping, etc.

[0112] I: The initial reservoir water level constraint is shown by the following formula:

[0113] Z cs = Z(1)

[0114] Where: Z cs is the initial reservoir water level in the planning period; Z(1) is the reservoir water level at the 1st moment within the planning period T, which is equal to the water level at the end of the reservoir impoundment period and is a known value.

[0115] In addition to meeting the above constraints, the dispatching operation of the reservoir hydropower station also needs to meet its own characteristic curve constraints, such as the reservoir water level - storage capacity relationship curve, the reservoir water level - discharge capacity curve, the downstream water level - flow relationship curve, the unit pre-outlet power limit line, and the plant optimal dynamic characteristic curve. In addition, all variables must be non-negative variables.

[0116] The economic operation of the unit aims to find the optimal number of operating units, combination, and the distribution of active power load among the operating units under the optimal criterion of power generation. According to the unique conversion relationship between the key variables of the reservoir type (the reservoir storage volume at the end of the period) and the key variables of the hydropower station type (the unit power generation output and the power generation flow at the period), considering the water-determined power generation mode, the reservoir storage volume at the end of the period is selected as the decision variable of the unit economic operation model.

[0117] In one embodiment, step S3: Based on the constructed unit economic operation model, the locust optimization algorithm is used to find the optimal economic operation strategy of each period's operating units under the optimal criterion of power generation, which specifically includes the following steps:

[0118] Step S31: Set the locust algorithm parameters and initialize the population; specifically, set the locust population size N pop 、the maximum number of iterations G max 、the minimum value C of the attenuation coefficient minand the maximum value C max ; Use real - number coding method to code and randomly generate N pop -scale decision variables, that is, the reservoir water level V(t + 1) at the end of the time period;

[0119] Step S32: Evaluate the fitness of the initialized population to generate the offspring locust population; specifically, evaluate the fitness of the initialized population, divide the locust population into grades according to the obtained fitness; perform roulette wheel operation to select the locust population with the maximum fitness (i.e., elitist retention strategy) to generate an offspring locust population with a scale still N pop ;

[0120] Step S33: As Figure 5 shown, based on the constructed unit economic operation model, simulate the unit economic operation process, and satisfy the physical constraints of the reservoir - hydropower station - unit, and perform iterative optimization on the generated offspring locust population; specifically, simulate the unit economic operation process and need to satisfy the physical constraints of the reservoir - hydropower station - unit. According to the locust swarm behavior, divide the activity area of locust individuals into an attraction area (0, a 1 , a comfort area (a 1 , a 2 , and a repulsion area (a 2 , a 3 , where 0 < a 1 < a 2 < a 3 ; Perform iterative optimization on the generated offspring locust population. The update calculation formula of the attenuation coefficient c k at the k - th iteration and the calculation formula of the position of the locust individual in the swarm are shown as follows:

[0121] c k = C max - k·(C max - C min ) / G max

[0122]

[0123] In the formula, c k is the attenuation coefficient at the k - th iteration, used to adjust the ranges of the attraction area, comfort area and repulsion area; is the position vector of the j - th locust individual for the d - th (d = 1, 2,..., D) decision variable, where D is the number of decision variables; is the best position vector of the d - th decision variable; U d and L d are respectively the upper and lower limits of the constraints of the d - th decision variable; and The positions of the d-th (d = 1, 2, …, D) decision variables of the n-th locust individual and the j-th locust individual, respectively; is the unit vector from the position of the j-th locust individual to the position of the n-th locust individual; s(x) is the swarm behavior function of the independent variable x, where the parameters F and L are the attraction intensity and the attraction distance scale of the attraction area, respectively.

[0124] Step S34: Obtain the iteration termination situation of the offspring locust population according to the current iteration number. When the iteration terminates, output the optimal economic operation strategy of the working units in each period under the criterion of optimal power generation; specifically, if the current iteration number is less than the maximum iteration number G max , then repeat steps ② to ④; otherwise, terminate the calculation and output the optimal economic operation strategy of the working units in each period under the criterion of optimal power generation.

[0125] Based on step S3, considering constraint conditions such as the predicted runoff and the total water consumption, the locust optimization algorithm is used to seek the optimal number, combination of the working units in each period and the distribution of the active power load among the working units under the criterion of optimal power generation, providing scientific support for guiding the economic operation of the units under the drought limit water level control of the reservoir.

[0126] In a second aspect, the present application provides a unit economic operation system based on the drought limit water level control of a reservoir, including:

[0127] A phased drought limit water level acquisition module, configured to calculate and obtain the phased drought limit water level of the reservoir by using the hourly sliding calculation method respectively during each phase of the dry season of the reservoir;

[0128] A unit economic operation model construction module, communicatively connected to the phased drought limit water level acquisition module, configured to construct a unit economic operation model with maximizing the total power generation of the reservoir during the planned period as the objective function and satisfying the physical constraint conditions of the reservoir - hydropower station - units based on the phased drought limit water level of the reservoir;

[0129] An optimal economic operation strategy acquisition module, communicatively connected to the unit economic operation model construction module, configured to seek the optimal economic operation strategy of the working units in each period under the criterion of optimal power generation by using the locust optimization algorithm based on the constructed unit economic operation model.

[0130] Combined with the second aspect, in an implementation manner, the phased drought limit water level acquisition module includes:

[0131] A reservoir dry season water consumption acquisition unit, configured to deduce the water consumption of the reservoir during the dry season by following the principle of "summation for non - combinable water intake and taking the maximum value for combinable water intake";

[0132] The reservoir water supply requirement acquisition unit, communicatively connected to the reservoir low-flow period water consumption acquisition unit, is configured to calculate the reservoir water supply requirement under the extremely low-flow scenario by using the step-by-step sliding calculation method according to the calculated reservoir low-flow period water consumption.

[0133] The phased dry-season limit water level value acquisition unit, communicatively connected to the reservoir water supply requirement acquisition unit, is configured to determine the phased dry-season limit water level value by combining the reservoir water level corresponding to the maximum value of the sum of the reservoir water supply requirement under the extremely low-flow scenario and the dead storage capacity and the reservoir water intake implementation elevation.

[0134] Among them, the function implementation of each module in the above unit economic operation system based on the reservoir dry-season limit water level control corresponds to each step in the above unit economic operation method embodiment based on the reservoir dry-season limit water level control, and its function and implementation process will not be elaborated here one by one.

[0135] In a third aspect, an embodiment of the present application provides a unit economic operation device based on the reservoir dry-season limit water level control. The unit economic operation device based on the reservoir dry-season limit water level control can be a device with data processing functions such as a personal computer (PC), a laptop computer, a server, etc.

[0136] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces, etc., which are used to implement the interconnection of components inside the unit economic operation device based on the reservoir dry-season limit water level control, and interfaces for implementing the interconnection of the unit economic operation device based on the reservoir dry-season limit water level control with other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, an optical fiber interface, an ATM interface, etc.; the user device can be a display screen (Display), a keyboard (Keyboard), etc.

[0137] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical memory, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0138] The processor may be a general-purpose processor, which can call the unit economic operation program based on the drought limit water level control of the reservoir stored in the memory and execute the unit economic operation method based on the drought limit water level control of the reservoir provided in the embodiments of the present application. For example, the general-purpose processor may be a central processing unit (CPU). Among them, the method executed when the unit economic operation program based on the drought limit water level control of the reservoir is called may refer to the various embodiments of the unit economic operation method based on the drought limit water level control of the reservoir in the present application, which will not be elaborated here.

[0139] Fourthly, the embodiments of the present application further provide a readable storage medium.

[0140] The unit economic operation program based on the drought limit water level control of the reservoir is stored on the readable storage medium of the present application. When the unit economic operation program based on the drought limit water level control of the reservoir is executed by a processor, the steps of the unit economic operation method based on the drought limit water level control of the reservoir as described above are realized.

[0141] Among them, the method realized when the unit economic operation program based on the drought limit water level control of the reservoir is executed may refer to the various embodiments of the unit economic operation method based on the drought limit water level control of the reservoir in the present application, which will not be elaborated here.

[0142] It should be noted that the serial numbers of the above embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0143] Through the description of the above embodiments, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they 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 application, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product is stored in a storage medium as described above (such as ROM / RAM, magnetic disk, optical disc) and includes several instructions for causing a terminal device to execute the methods described in the various embodiments of the present application.

[0144] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the description of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A method for economic operation of a unit based on reservoir drought limit water level control, characterized in that: The following steps are involved: In each phase of the reservoir's dry season, the period-by-period sliding calculation method is used to calculate the reservoir's phased drought limit water level; Based on the reservoir's phased drought limit water level, a unit economic operation model is constructed with the objective function of maximizing the total power generation of the reservoir during the planning period and satisfying the physical constraints of the reservoir-hydropower station-unit; The objective function is shown in the following formula: Where: T is the planning period; is the total power generation of the reservoir during the planning period, For the t The number of units that can be put into operation at any time is less than or equal to the total number of units; w is the number of the unit put into operation, less than or equal to ; For the t Moment w The factory number corresponding to the unit can be put into use; For the factory g The output of unit No. Based on the constructed unit economic operation model, the locust optimization algorithm is used to seek the optimal economic operation strategy of the units working in each period under the optimal power generation criterion.

2. The method for economic operation of a unit based on reservoir drought limit water level control according to claim 1, characterized in that: In each phase of the dry season of the reservoir, the period-by-period sliding calculation method is used to calculate and obtain the phased drought limit water level of the reservoir, which specifically includes the following steps: Following the principle of "summing up the water intakes that cannot be combined and taking the maximum value of the water intakes that can be combined", the water consumption of the reservoir during the dry season is deduced; Based on the estimated water consumption of the reservoir during the dry season, the time-by-time sliding calculation method is used to calculate the water supply required by the reservoir under the extremely dry season scenario; The drought limit water level values ​​in different phases are determined based on the reservoir water level corresponding to the maximum value of the sum of the reservoir's water supply and dead storage capacity under extremely dry conditions and the reservoir water intake implementation elevation.

3. The method for economic operation of a unit based on reservoir drought limit water level control as claimed in claim 2, characterized in that: Following the principle of "summing up water that cannot be combined and taking the maximum value of water that can be combined", the water consumption of the reservoir during the dry season is deduced as follows: Where: for t Reservoir water consumption during the period; and They are t Water consumption above and below the dam during the period; for t Water supply on the dam during the period; , and They are t The water consumption for power generation, irrigation and environmental ecology under the dam during the period.

4. The method for economic operation of a unit based on reservoir drought limit water level control as claimed in claim 2, characterized in that: Based on the estimated water consumption of the reservoir during the dry season, the water supply of the reservoir under the extremely dry season scenario is calculated using the sliding calculation method for each period as shown in the following formula: Where: for t The amount of water that the reservoir should supply during the period.

5. The method for economic operation of a unit based on reservoir drought limit water level control as claimed in claim 2, characterized in that: The reservoir water level corresponding to the maximum value of the sum of the reservoir water supply and dead storage capacity under the extremely dry scenario and the reservoir water intake implementation elevation are determined as follows: Where: for t The amount of water that the reservoir should supply during the period, For the i Stage t The amount of water that the reservoir should supply during the period; For the i The maximum value of the sum of the water supply and dead storage capacity of the reservoir in each phase; For the i The reservoir water level corresponding to the maximum value of the sum of the water supply and dead storage capacity of the reservoir in each phase; It is the elevation of the reservoir water intake facility; For the i The drought limit water level of the reservoir is divided into stages.

6. The method for economic operation of a unit based on reservoir drought limit water level control according to claim 1, characterized in that: The physical constraints of the reservoir-hydropower station-unit specifically include total water volume constraints, reservoir hydropower station water balance constraints, reservoir water level constraints, unit head constraints, unit output limitations, unit water consumption characteristics, hydropower station total output limitations, comprehensive utilization constraints and initial reservoir water level constraints; wherein the initial reservoir water level is equal to the water level at the end of the reservoir storage period.

7. The method for economic operation of a unit based on reservoir drought limit water level control as claimed in claim 1, characterized in that: The economic operation model of the unit constructed by the locust optimization algorithm is used to seek the optimal economic operation strategy of the unit in each period under the optimal power generation criterion, which specifically includes the following steps: Set locust algorithm parameters and initialize the population; Evaluate the fitness of the initialized population and generate the offspring locust population; The economic operation process of the unit is simulated based on the constructed unit economic operation model, and the physical constraints of the reservoir-hydropower station-unit are met, and the generated locust population is iteratively optimized; The iteration termination situation of the offspring locust population is obtained according to the current number of iterations. When the iteration is terminated, the optimal economic operation strategy of the working units in each period under the optimal power generation criterion is output.

8. A system using the unit economic operation method based on reservoir drought limit water level control as described in any one of claims 1 to 7, characterized in that: include: The module for obtaining drought limit water level in stages is used to calculate and obtain the drought limit water level in stages of the reservoir by using the sliding calculation method in each period in the dry season of the reservoir; A unit economic operation model construction module is communicated with the phased drought limit water level acquisition module and is used to construct a unit economic operation model based on the phased drought limit water level of the reservoir, with the objective function of maximizing the total power generation of the reservoir during the planning period and satisfying the physical constraints of the reservoir-hydropower station-unit; The optimal economic operation strategy acquisition module is communicated with the unit economic operation model construction module and is used to seek the optimal economic operation strategy of the unit working in each time period under the optimal power generation criterion by using the locust optimization algorithm based on the constructed unit economic operation model.

9. The system according to claim 8, characterized in that The phased drought limit water level acquisition module includes: The unit for obtaining the water consumption in the dry season of the reservoir is used to follow the principle of "summing up the water intakes that cannot be combined and taking the maximum value of the water intakes that can be combined" to deduce the water consumption in the dry season of the reservoir; A reservoir water supply acquisition unit is connected to the reservoir dry season water consumption acquisition unit for calculating the reservoir water supply under the extreme dry season scenario by using a sliding calculation method based on the estimated reservoir dry season water consumption; The phased drought limit water level value acquisition unit is communicatively connected with the reservoir water supply acquisition unit, and is used to determine the phased drought limit water level value by combining the reservoir water level corresponding to the maximum value of the sum of the reservoir water supply and the dead storage capacity under the extreme drought scenario and the reservoir water intake implementation elevation.

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