Method for optimizing area of surge chamber of pumped storage power station and related device

Abstract

The invention discloses a surge chamber area optimization method of a pumped storage power station and a related device. The method comprises the following steps: firstly, establishing a mathematical model of the pumped storage power station provided with upstream and downstream surge chambers; then, based on the mathematical model, establishing decision variables for optimizing the surge chamber system, determining constraint conditions of optimization parameters, and establishing a surge chamber fitness objective function about comprehensive optimization of the maximum water level fluctuation value and the water level change attenuation degree of the upstream and downstream surge chamber system; and finally, solving through a firefly algorithm to obtain an optimal upstream and downstream surge chamber area combination. According to the method, the pumped storage power station model with the upstream and downstream surge chambers is established, and the firefly algorithm is applied to the surge chamber area optimization of the pumped storage power station with the upstream and downstream surge chambers, so that the calculation speed is higher and the convergence rate is higher in the optimization process of the optimization parameters, and the problems that the prior art is not comprehensive enough in consideration, and the convergence rate is higher are solved. And the optimal upstream and downstream surge chamber area combination cannot be quickly and accurately obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of pumped storage power stations, and particularly to a novel roof structure for a prefabricated cabin substation. Background Art

[0002] A pumped storage power station is a special type of hydropower station that uses electrical energy during low electricity load periods to pump water to an upper reservoir and releases the water to a lower reservoir for power generation during high electricity load peaks. Usually, a pumped storage power station reduces water hammer pressure and enhances the safe operation performance by setting up upstream and downstream double surge chambers. However, pumped storage power stations have characteristics such as complex and variable hydraulic coupling processes and very large water flow inertia time constants, making the impact of water level fluctuations and hydraulic interference formed between different operating conditions of the units on system stability more complex.

[0003] Regarding the problem of the fluctuation stability of the upstream and downstream double surge chamber system, domestic and foreign scholars have also started to conduct research in recent years. Gubin and Jaeger studied the fluctuation stability problem of the upstream and downstream surge chambers. Suo Lisheng analyzed the small fluctuation stability and dynamic quality of the turbine regulating system with upstream and downstream double surge chambers by establishing differential equations and transfer matrices of small fluctuations. Lai Xu considered the change law of the stability domain of a hydropower station with upstream and downstream double surge chambers when fully considering the role of the governor, and analyzed the influence of governor parameters on the stability domain, and proposed a calculation formula for the stable section that meets the needs of actual engineering design. However, the formula and analysis process given are not comprehensive enough, and the influence of the surge chamber area on the stability of the surge chamber water level fluctuation is not considered. Therefore, the optimization of the surge chamber area under load increase and decrease urgently needs to be studied. Summary of the Invention

[0004] The present invention provides a method and related device for optimizing the surge chamber area of a pumped storage power station to solve the problem that the existing technology is not comprehensive enough and cannot quickly and accurately obtain the optimal combination of upstream and downstream surge chamber areas.

[0005] In view of this, in the first aspect of the present application, a method for optimizing the surge chamber area of a pumped storage power station is provided. The method includes:

[0006] Establishing a mathematical model of a pumped storage power station with upstream and downstream double surge chambers;

[0007] Based on the mathematical model, constructing decision variables for optimizing the surge chamber system, determining the constraint conditions of the optimization parameters, and establishing a surge chamber fitness objective function that is comprehensively optimal for the maximum value of the water level fluctuation and the attenuation degree of the water level change of the upstream and downstream surge chamber systems;

[0008] Combining the decision variables, the constraint conditions, and the surge chamber fitness objective function, and solving through the firefly algorithm to obtain the optimal combination of upstream and downstream surge chamber areas.

[0009] Optionally, the establishing of a mathematical model of a pumped storage power station with a downstream double surge chamber includes:

[0010] The diversion tunnel equation, tailwater tunnel equation, upstream and downstream surge chamber continuity equation, upstream and downstream surge chamber long connecting pipe equation, pressure pipe equation, pump turbine torque and flow equation, generator motor equation and speed governor equation are constructed respectively and combined to obtain the seventh-order state equation of the pumped-storage power station system with upstream and downstream double surge chambers.

[0011] Optionally, the expression of the seventh-order state equation is:

[0012] ;

[0013] In the formula, is the inertia time constant of water flow in the pressure pipe, H0 is the working water head of the unit, is the relative working head of the unit, is the relative head loss of the pressure pipe, is the relative flow rate of the pressure pipeline; The relative water level fluctuation of the upstream and downstream surge chambers. is the time constant of the upstream and downstream surge chambers, is the inertia time constant of the water flow in the long connecting pipe of the upstream and downstream surge tanks, is the head loss coefficient of the long connecting pipe of the upstream and downstream surge tanks; is the relative value of the water head of the pressure measuring pipe at the bottom of the upstream and downstream pressure regulating chambers, For the diversion tunnel, the initial relative head loss of the tailrace tunnel is is the inertia time constant of water flow in the diversion tunnel and tailrace tunnel, For water diversion, the tailrace tunnel relative flow; is the relative value of the water head of the pressure measuring pipe at the bottom of the upstream and downstream pressure regulating chambers, For the diversion tunnel, the initial relative head loss of the tailrace tunnel is is the turbine resistance torque; is the load self-regulation coefficient, is the unit inertia time constant, is the proportional gain of the speed regulator; is the speed regulator integral gain, is the turbine torque transfer coefficient; is the turbine flow transfer coefficient.

[0014] Optionally, the decision variables for constructing the surge chamber system optimization include:

[0015] The parameters that determine the operating stability of the surge chamber are used as decision variables for optimizing the surge chamber system, and the parameters include: an upstream surge chamber area and a downstream surge chamber area.

[0016] Optionally, the constraints for determining the optimization parameters include:

[0017] Determine the constraints of the optimization parameters preliminarily according to the Thoma section formula, and the constraints include:

[0018] < <C

[0019] < <C

[0020]

[0021] > 0, > 0

[0022] In the formula, is the cross-sectional area of the upstream surge chamber, is the cross-sectional area of the downstream surge chamber, is the cross-sectional area of the Thoma critical section of the upstream surge chamber, is the cross-sectional area of the Thoma critical section of the downstream surge chamber, C is a given constant, is the attenuation degree of the water level change in the upstream surge chamber, is the attenuation degree of the water level change in the downstream surge chamber.

[0023] Optionally, the expression of the fitness objective function of the surge chamber is:

[0024]

[0025] In the formula, is the maximum value of the water level fluctuations in the upstream and downstream surge chambers in the dynamic response of the surge chamber water level; is the attenuation degree of the water level change in the upstream and downstream surge chambers in the dynamic response; is the corresponding weight value.

[0026] Optionally, combining the decision variables, the constraints, and the fitness objective function of the surge chamber, and solving through the firefly algorithm to obtain the optimal combination of the upstream and downstream surge chamber areas, including:

[0027] S11. Set the firefly algorithm parameters, initialize the firefly population and firefly positions, including: initialize the surge chamber area parameters of the pumped-storage power station with upstream and downstream double surge chambers;

[0028] S12. By applying a load disturbance, obtain the dynamic responses of the upstream and downstream surge chamber water levels. Calculate and process the dynamic responses to obtain the maximum values of the water level fluctuations in the upstream and downstream surge chambers and the attenuation degrees of the water level changes in the upstream and downstream surge chambers, and then substitute them into the surge chamber fitness objective function to obtain the fitness value;

[0029] S13. Use the fitness value as the brightness of the firefly, calculate the relative brightness and attraction between each pair of fireflies, and perform a movement operation based on the relative brightness magnitude to update the firefly positions and the brightness;

[0030] S14. Loop through steps S12 and S13 until the preset maximum iteration count limit is reached, and output the optimal solution, which is the optimal combination of the upstream and downstream surge chamber areas.

[0031] The second aspect of this application provides a surge chamber area optimization system for a pumped-storage power station. The system includes:

[0032] A first construction unit for establishing a mathematical model of a pumped-storage power station with upstream and downstream double surge chambers;

[0033] A second construction unit for constructing decision variables for the optimization of the surge chamber system based on the mathematical model, determining the constraint conditions of the optimization parameters, and establishing a surge chamber fitness objective function that is comprehensively optimal for the maximum water level fluctuations and the attenuation degrees of the water level changes in the upstream and downstream surge chamber systems;

[0034] A solution unit for solving to obtain the optimal combination of the upstream and downstream surge chamber areas through a firefly algorithm in combination with the decision variables, the constraint conditions, and the surge chamber fitness objective function.

[0035] The third aspect of the present invention provides a surge chamber area optimization device for a pumped-storage power station. The device includes a processor and a memory:

[0036] The memory is used to store program code and transmit the program code to the processor;

[0037] The processor is used to execute the steps of the surge chamber area optimization method for a pumped-storage power station as described in the first aspect above according to the instructions in the program code.

[0038] The fourth aspect of the present invention provides a computer-readable storage medium for storing program code, and the program code is used to execute the surge chamber area optimization method for a pumped-storage power station as described in the first aspect above.

[0039] From the above technical solutions, it can be seen that the present invention has the following advantages:

[0040] An optimization method for the area of the surge chamber of a pumped-storage power station provided by an embodiment of the present invention optimizes the areas of the upstream and downstream surge chambers of a pumped-storage power station with upstream and downstream double surge chambers. First, a mathematical model of a pumped-storage power station with upstream and downstream double surge chambers is established, and the decision variables, constraint conditions, and objective function for optimizing the water level fluctuations in the two surge chambers are determined. The theoretical basis and algorithm flow of the research on the optimization of the surge chamber area based on the firefly algorithm are analyzed, and the optimization research on the surge chamber area under load reduction disturbance of a certain pumped-storage power station with upstream and downstream double surge chambers is carried out, and the optimal combination of the areas of the upstream and downstream surge chambers of the pumped-storage power station with upstream and downstream surge chambers under load reduction disturbance is obtained.

[0041] In the present invention, considering the complex hydraulic coupling relationship between the upstream and downstream double surge chambers and the problem of hydraulic vibration caused by the hydraulic coupling effect, a mathematical model of a pumped-storage power station with upstream and downstream double surge chambers is established. Further, an optimization method for the surge chamber area parameters of a pumped-storage power station with upstream and downstream double surge chambers is proposed. Considering that the optimization problem of the surge chamber area is essentially a problem of comprehensive system benefits, the value of fitness is used as the brightness of the firefly, the relative brightness and attraction between each pair of fireflies are calculated, and the movement operation is carried out through the relative brightness size, so as to update the position and brightness of the firefly. A disturbance step size is added to avoid the firefly falling into local optimum. The optimization process of the firefly algorithm is simple, with few parameters to be adjusted and excellent performance. Thus, the problem that the existing technology is not comprehensive enough and cannot quickly and accurately obtain the optimal combination of the areas of the upstream and downstream surge chambers is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0043] Figure 1 It is a schematic flow chart of an optimization method for the area of the surge chamber of a pumped-storage power station provided by an embodiment of the present invention;

[0044] Figure 2 It is a schematic diagram of a pumped-storage power station system with upstream and downstream double surge chambers provided by an embodiment of the present invention;

[0045] Figure 3 It is a program flow chart of the firefly algorithm provided by an embodiment of the present invention;

[0046] Figure 4a 、 Figure 4b and Figure 4c It is a graph of the number of iterations of the firefly algorithm provided by an embodiment of the present invention and a pumped-storage power station with upstream and downstream double surge chambers under load disturbance Time domain diagram of transient response of water level in upstream and downstream surge chambers;

[0047] Figure 5 A schematic flow chart of a method for optimizing the area of a surge chamber of a pumped-storage power station provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] See also Figure 1 , a method for optimizing the surge chamber area of a pumped storage power station provided in an embodiment of the present invention comprises:

[0050] Step 101: Establish a mathematical model of a pumped-storage power station with upstream and downstream double surge chambers.

[0051] It should be noted that the pumped storage power station with upstream and downstream double surge chambers is a special pumped storage power station. A pumped storage power station is a power station that uses the excess electricity in the low valley of the power system to pump water from the lower reservoir to the upper reservoir for storage. When the power system is at peak load, the water in the upper reservoir is released to generate electricity through the turbine, which plays the role of peak regulation, valley filling, energy storage, etc., and improves the stability and economy of the power system. The "upstream and downstream double surge chambers" are an important feature of the power station. The surge chamber is a building connecting the water diversion channel and the turbine. Its function is to reduce the impact of water hammer pressure on the water diversion system and the turbine by adjusting the water level and flow when the load of the hydropower station changes, so as to ensure the stable operation of the unit. The upstream and downstream double surge chambers mean that surge chambers are set up upstream and downstream of the power station respectively. The upstream surge chamber is mainly used to adjust the pressure and flow changes in the water diversion channel from the reservoir to the turbine; the downstream surge chamber is mainly used to adjust the pressure and flow fluctuations in the tailwater tunnel from the turbine to the lower reservoir. By setting up double upstream and downstream surge chambers, it is possible to more effectively cope with the hydraulic transition process under complex working conditions, enhance the safety and reliability of power station operation, and adapt to more frequent and drastic load changes.

[0052] The present invention optimally designs the areas of the upstream and downstream surge chambers of a pumped-storage power station by establishing a mathematical model of a pumped-storage power station with upstream and downstream double surge chambers. This mathematical model comprehensively considers various aspects such as the operating conditions, hydraulic characteristics, structural safety, and economy of the power station. Through precise calculation and analysis, the optimal areas of the upstream and downstream surge chambers under different operating conditions are determined to ensure the stable operation of the power station, improve power generation efficiency, and reduce construction and operation costs. This method utilizes advanced numerical calculation techniques and optimization algorithms to achieve precise design and optimization of the surge chamber area of the pumped-storage power station, providing strong support for the safe and efficient operation of the power station.

[0053] Step 102: Based on the mathematical model, construct decision variables for the optimization of the surge chamber system, determine the constraint conditions of the optimization parameters, and establish a fitness objective function for the surge chamber that is comprehensively optimal for the maximum water level fluctuation and the attenuation degree of water level change in the upstream and downstream surge chamber systems.

[0054] It should be noted that in Step 102, for the mathematical model of a pumped-storage power station with upstream and downstream double surge chambers, combined with the basic principle of the firefly algorithm, the range of decision variables is defined, providing a basis for subsequent optimization calculations. And corresponding constraint conditions are set up to preliminarily determine the value range of the optimization variables, narrow the search range of the algorithm, reduce the calculation time of the algorithm, and exclude unreasonable surge chamber areas. By clarifying the corresponding objective function, it is used to evaluate the advantages and disadvantages of different surge chamber area combination schemes, thus providing theoretical support for the optimization research on the area combination of the upstream and downstream surge chambers of a pumped-storage power station based on the firefly algorithm.

[0055] Step 103: Combine the decision variables, constraint conditions, and the fitness objective function of the surge chamber, and solve through the firefly algorithm to obtain the optimal combination of the upstream and downstream surge chamber areas.

[0056] It should be noted that by combining the decision variables, constraint conditions, and the fitness objective function of the surge chamber, the optimal combination of the upstream and downstream surge chamber areas is obtained through the firefly algorithm. The present invention utilizes the powerful search ability of the firefly algorithm to find the optimal solution that satisfies the constraint conditions within the range of decision variables. Through continuous iterative calculations, the system can gradually approach the optimal combination of the upstream and downstream surge chamber areas, enabling key indicators such as the maximum water level fluctuation and the attenuation degree of water level change in the surge chamber system to reach the optimal state. Finally, the system outputs the optimal surge chamber area combination scheme, providing a scientific basis for the design and operation of the pumped-storage power station.

[0057] In one embodiment, Step 101 includes:

[0058] The diversion tunnel equation, tailwater tunnel equation, upstream and downstream surge chamber continuity equation, upstream and downstream surge chamber long connecting pipe equation, pressure pipe equation, pump turbine torque and flow equation, generator motor equation and speed governor equation are constructed respectively and combined to obtain the seventh-order state equation of the pumped-storage power station system with upstream and downstream double surge chambers.

[0059] It should be noted that the pumped storage power station with upstream and downstream double surge chambers in this embodiment includes upstream and downstream reservoirs, a water diversion tunnel, an upper surge chamber, a pressure pipeline, a generator, a speed governor, a turbine, a downstream surge chamber and a tailwater tunnel. Figure 2 shown.

[0060] in:

[0061] (1) The turbine torque and flow equations are:

[0062]

[0063]

[0064] (2) The speed regulator equation is:

[0065]

[0066] (3) The generator equation is:

[0067]

[0068] (4) The water diversion tunnel equation is:

[0069]

[0070] (5) The tailwater tunnel equation is:

[0071]

[0072] (6) The continuity equation of the upstream surge tank is:

[0073]

[0074] (7) The continuity equation of the downstream surge tank is:

[0075]

[0076] (8) The dynamic equation of the pressure pipeline is:

[0077]

[0078] (9) The equation for the long connecting pipe of the upstream surge tank is:

[0079]

[0080] (10) The equation of the long connecting pipe of the downstream surge chamber is as follows:

[0081]

[0082] In the formula, is the inertia time constant of the water flow in the penstock, s; H0 is the working head of the unit, m; is the relative working head of the unit, m; is the relative head loss of the penstock, m; is the relative flow rate of the penstock, ; are the relative water level fluctuations of the upstream and downstream surge chambers, m. are the time constants of the upstream and downstream surge chambers, s. is the inertia time constant of the water flow in the long connecting pipe of the upstream and downstream surge chambers, s; is the head loss coefficient of the long connecting pipe of the upstream and downstream surge chambers; is the relative value of the piezometric head at the bottom of the upstream and downstream surge chambers, m; are the initial relative head losses of the intake tunnel and the tailrace tunnel, m. are the inertia time constants of the water flow in the intake tunnel and the tailrace tunnel, s; are the relative flow rates of the intake and tailrace tunnels, ; is the relative value of the piezometric head at the bottom of the upstream and downstream surge chambers, m; are the initial relative head losses of the intake tunnel and the tailrace tunnel, m. is the resistance torque of the turbine, N•m; is the load self-regulation coefficient, s; is the inertia time constant of the unit, s. is the proportional gain of the governor; is the integral gain of the governor, s ,

[0084] , , , , ,

[0083] , , , , , , ,

[0085] , , -1 , , , , , , . is the torque transfer coefficient of the turbine; is the flow transfer coefficient of the turbine.

[0083] By simultaneously solving the above equations, a seventh-order state equation is obtained. The expression of the seventh-order state equation is:

[0084] ;

[0085] In the formula, is the inertia time constant of the water flow in the penstock, H0 is the working head of the unit, is the relative working head of the unit, is the relative head loss of the penstock, is the relative flow rate of the penstock; is the upstream, and the relative water level fluctuation of the downstream surge chamber is the upstream and downstream surge chamber time constants is the water flow inertia time constant of the long connecting pipe of the upstream and downstream surge chambers is the head loss coefficient of the long connecting pipe of the upstream and downstream surge chambers is the relative piezometric head value at the bottom of the upstream and downstream surge chambers is the initial relative head loss of the intake tunnel and the tailrace tunnel is the water flow inertia time constant of the intake tunnel and the tailrace tunnel is the relative flow rate of the intake and tailrace tunnels is the relative piezometric head value at the bottom of the upstream and downstream surge chambers is the initial relative head loss of the intake tunnel and the tailrace tunnel is the resistance torque of the turbine is the load self-regulation coefficient is the inertia time constant of the unit is the proportional gain of the governor is the integral gain of the governor is the turbine torque transfer coefficient is the turbine flow transfer coefficient

[0086] In one embodiment, step 102 includes:

[0087] Taking the parameters that determine the operation stability of the surge chamber as the decision variables for the optimization of the surge chamber system, and the parameters include: the area of the upstream surge chamber and the area of the downstream surge chamber.

[0088] According to the Thoma section formula, initially determine the constraint conditions of the optimization parameters, and the constraint conditions include:

[0089] < <C

[0090] < <C

[0091]

[0092] > 0, > 0

[0093] Wherein, is the cross-sectional area of the upstream surge chamber, is the cross-sectional area of the downstream surge chamber, is the cross-sectional area of the Thoma critical section of the upstream surge chamber, is the cross-sectional area of the Thoma critical section of the downstream surge chamber, and C is a given constant, is the attenuation degree of the water level change in the upstream surge chamber, is the attenuation degree of the water level change in the downstream surge chamber.

[0094] Establish a fitness objective function for the surge chamber that is comprehensively optimal for the maximum water level fluctuation and the attenuation degree of the water level change in the upstream and downstream surge chamber systems; the expression of the fitness objective function of the surge chamber is:

[0095]

[0096] In the formula, is the maximum value of the water level fluctuations in the upstream and downstream surge chambers in the dynamic response of the surge chamber water level; is the attenuation degree of the water level change in the upstream and downstream surge chambers in the dynamic response; is the corresponding weight value.

[0097] It should be noted that in this embodiment, the area parameters of the upstream and downstream surge chambers that can determine the operation stability of the surge chamber are selected as the decision variables for the optimization of the surge chamber system, and the constraint conditions of the optimization parameters are preliminarily determined according to the Thoma section formula. By establishing a fitness objective function for the surge chamber that is comprehensively optimal for the maximum water level fluctuation and the attenuation degree of the water level change in the upstream and downstream surge chamber systems, it is used to evaluate the performance of the surge chamber.

[0098] Specifically, in order to improve the operation stability of the surge chamber system of the pumped-storage power station under different working conditions, the present invention selects the areas of the upstream and downstream surge chambers as decision variables, so as to reduce the water level fluctuation of the surge chamber and accelerate the stabilization of the water level change. The constructed constraint conditions preliminarily determine the value range of the optimization variables, narrow the search range of the algorithm, reduce the calculation time of the algorithm, and exclude unreasonable surge chamber areas. By constructing a fitness function, four indicators of , and two optimization parameters of , are selected, so as to ensure that the comprehensive benefits of the surge chamber system can reach the maximum for the optimized surge chamber area.

[0099] Among them, according to the Thoma critical section formula ( ), the minimum cross-sectional areas of the upstream and downstream surge chambers at critical stability can be obtained, and thus the constraint conditions of the optimization parameters are preliminarily determined as: . According to the Thoma critical stability section formula, the value range of the parameters within this constraint condition includes the parameter values within the stable region, which reduces the calculation time while ensuring the system stability; means finding the optimal solution through an optimization algorithm under the condition that the sum of the upstream and downstream areas is certain, which to a certain extent represents the economic consideration; and for the attenuation degree of the upstream and downstream water level changes > zero. If the attenuation degree is less than zero, it indicates that the water level fluctuation in the surge chamber becomes larger and larger over time and cannot stabilize.

[0100] To establish the fitness objective function of the surge chamber, the following steps are included:

[0101] First, the maximum value of the water level fluctuation can represent the severity of the water level change in the surge chamber to a certain extent.

[0102] Second, the attenuation degree of the water level change can indicate the speed at which the water level change in the surge chamber returns to stability. Therefore, the fitness function of the surge chamber consists of two indicators: the maximum value of the water level fluctuation and the attenuation degree of the water level change.

[0103] For the surge chamber system, assuming the optimization objective of the area parameters of the upstream and downstream double-surge chamber pumped-storage parameters is that under the load disturbances of each working condition, in the surge chamber system, the overall maximum value of the water level fluctuation is smaller, and the attenuation rate is larger. For the firefly optimization algorithm, the fitness function must be a monotonic function, so that the brightness of fireflies can be compared through the large / small fitness value. For the maximum value of the water level fluctuation , the smaller this indicator, the smaller the water level fluctuation. And for the attenuation rate , the larger this indicator, the faster the attenuation of the water level change, the faster the water level in the surge chamber stabilizes. By constructing 1 - to convert the objective function into a monotonic function, under this objective function, the smaller the fitness value, the better the result, and the higher the brightness of the firefly. Therefore, the objective function of the surge chamber can be established as:

[0104]

[0105] In one embodiment, step 103 includes:

[0106] Step 1031: Set the firefly algorithm parameters, initialize the firefly population and the firefly positions, including: initialize the area parameters of the surge chamber of the pumped-storage power station with upstream and downstream double-surge chambers.

[0107] It can be understood that setting the firefly algorithm parameters, initializing the firefly population, and initializing the firefly positions, that is, initializing the area parameters of the surge chamber of the pumped-storage power station with upstream and downstream double-surge chambers.

[0108] Step 1032: By applying load disturbances, obtain the dynamic responses of the water levels in the upstream and downstream surge chambers, calculate and process the dynamic responses to obtain the maximum values of the water level fluctuations in the upstream and downstream surge chambers and the attenuation degrees of the water level changes in the upstream and downstream surge chambers, and then substitute them into the fitness objective function of the surge chamber to obtain the fitness value.

[0109] It is understandable that by applying appropriate load disturbances, the dynamic responses of the upstream and downstream surge chamber water levels are obtained, and the maximum values of the water level fluctuations in the upstream and downstream surge chambers are obtained through the calculation and processing of the dynamic responses. , the attenuation degree of the water level change in the upstream and downstream surge chambers , and then substituting it into the fitness objective function to obtain the fitness value.

[0110] Step 1033: Take the fitness value as the brightness of the firefly, calculate the relative brightness and attraction between each pair of fireflies, and perform a movement operation according to the relative brightness magnitude, thereby updating the firefly position and brightness.

[0111] Step 1034: Loop steps 1032 and 1033 until the preset maximum iteration number limit is reached, and output the optimal solution, which is the optimal combination of the upstream and downstream surge chamber areas.

[0112] It is understandable that loop steps 1032 and 1033 until the maximum iteration number limit is reached, and output the brightest firefly, that is, the optimal solution, thereby giving the final optimal combination of the upstream and downstream surge chamber areas.

[0113] As Figure 3 shown, the specific process of the firefly algorithm to find the optimal solution includes the following sub-steps:

[0114] 1) Set the firefly population size according to the complexity of the problem. The more complex the problem, the larger the population size. Set the light absorption coefficient , the maximum attractiveness , the random perturbation factor and the maximum number of iterations. Randomly generate the positions of fireflies within the solution space of the problem. Each position represents a potential solution and ensure that the firefly positions satisfy the constraints of the problem.

[0115] 2) Evaluate each firefly position according to the surge chamber fitness objective function, and take the objective function value as the firefly brightness value. Compare the brightness of each firefly i with that of all other fireflies j. If firefly j is brighter than firefly i, then firefly i moves towards firefly j, calculate the distance between firefly i and j, and calculate the attractiveness β of firefly j to firefly i according to the distance . Update the position of firefly i according to the attractiveness β and random perturbation. After updating the firefly position, it is necessary to check whether it exceeds the solution space of the problem. If it exceeds the boundary, the position should be restricted within the boundary.

[0116] 3) Perform loop iteration on step 2). During the iteration process, the parameters can be dynamically adjusted, so that the convergence accuracy of the algorithm is higher, the optimization range is wider. When the upper limit of the iteration times is reached, output the found optimal upstream and downstream surge tank area combinations, as well as the corresponding objective function values, and output the convergence curve of the algorithm to analyze the performance of the algorithm.

[0117] The following are simulation examples:

[0118] This implementation aims at the simulation analysis of the load increase and decrease conditions of a pumped-storage power station with upstream and downstream surge tanks, to illustrate the optimization process and results of the surge tank area parameters of a pumped-storage power station with upstream and downstream surge tanks.

[0119] Taking the optimization study of the surge tank area parameters of a one-hole-one-machine pumped-storage power station with upstream and downstream surge tanks under load disturbance as an example, the method of the present invention will be described in detail. The basic data of this pumped-storage power station are as follows: The basic data of a one-hole-one-machine pumped-storage power station with upstream and downstream surge tanks are as follows: Rated head , Rated flow , The length of the water diversion tunnel is , The area of the water diversion tunnel is , The length of the tailwater tunnel is , The area of the tailwater tunnel is , The relevant water flow inertia time constant , , , , , The relevant relative head loss , , , The relative head loss coefficient , , The transfer coefficient of the pump-turbine takes the ideal value , , , , , , The governor parameter values are , , , .

[0120] Based on the firefly algorithm, the optimization simulation process of the surge tank area parameters of a pumped-storage power station with upstream and downstream surge tanks under load disturbance is as follows:

[0121] According to the fitness function, define the objective function, set the number of fireflies to 20, the maximum number of iterations to 40, the absorption coefficient to γ = 1.0, the maximum attractiveness to β0 = 2.0, the random perturbation step size to α = 0.2, the corresponding weight factor coefficients to ω1 = 0.25, ω2 = 0.25, ω3 = 0.25, ω4 = 0.25, and the decision variable constraint condition to 50 < ≤ 500, 120 < ≤ 500, and .

[0122] Initialize the positions of the fireflies, randomly generate 20 firefly positions within the search space, calculate the brightness of each firefly according to the fitness function, move the fireflies according to the brightness of the fireflies, and update the positions of the fireflies. Continuously iterate in a loop. When the maximum number of iterations is reached, the algorithm terminates, and the optimal solution found and the corresponding objective function value are output.

[0123] The corresponding results before and after optimization obtained by simulation are as Figures 4a - 4c shown:

[0124] Under the load disturbance , the areas of the upstream and downstream surge chambers and the maximum values of the corresponding water level fluctuations, the attenuation degrees of the water level changes, and the corresponding fitness values obtained without optimization and after firefly optimization are shown in Table 1:

[0125] Table 1 Parameters of the upstream and downstream surge chambers before and after optimization under the load reduction condition

[0126]

[0127] Analysis Figures 4a through 4c and Table 1 show that:

[0128] For the pumped-storage power station with upstream and downstream surge chambers based on the firefly algorithm, under the load disturbance , the optimization of the area parameters of the downstream surge chamber can obtain the optimal combination of the areas of the upstream and downstream surge chambers when the sum of the areas of the upstream and downstream surge chambers is certain. Increasing the area F of the surge chamber will improve the two indicators of the maximum value of the water level fluctuation and the attenuation degree of the water level change, that is, the maximum value of the water level fluctuation decreases and the attenuation degree of the water level change increases. However, increasing the area of one surge chamber will decrease the area of the other surge chamber, and the corresponding two indicators will deteriorate.

[0129] Under the load disturbance Under steady state, the larger the surge tank area F is, the better the transient response performance of the pumped-storage power station with upstream and downstream double surge tanks can be obtained. The larger the surge tank area F is, the more stable the water level fluctuation in the surge tank can be, and the faster the water level change can decay. However, a larger surge tank area also means an increase in the amount of work, resulting in higher construction costs. According to the iteration number graph, it can be found that in this optimization process, only a few iterations are required to find the optimal combination of the upstream and downstream surge tank areas, indicating that the firefly algorithm has a fast optimization calculation speed and a high convergence rate. Since the sum of the areas of the upstream and downstream surge tanks is a fixed value, it means that after optimization, one of the surge tank areas will be larger than the area before optimization, and the other will be smaller than the area before optimization. This also means that the water level change of one surge tank will be improved, while the water level change of the other surge tank will become worse. Due to the different layouts of the upstream and downstream flow channels, the most suitable areas for the upstream and downstream surge tanks are different. Therefore, the overall optimal surge tank can be obtained through optimization.

[0130] A method for optimizing the surge tank area of a pumped-storage power station provided by an embodiment of the present invention optimizes the areas of the upstream and downstream surge tanks of a pumped-storage power station with upstream and downstream double surge tanks. First, a mathematical model considering a pumped-storage power station with upstream and downstream double surge tanks is established, and the decision variables, constraint conditions, and objective function for optimizing the water level fluctuations in the two surge tanks are determined. The theoretical basis and algorithm flow of the research on optimizing the surge tank area based on the firefly algorithm are analyzed, and the optimization research on the surge tank area of a certain pumped-storage power station with upstream and downstream double surge tanks under load reduction disturbance is carried out, and the optimal combination of the upstream and downstream surge tank areas of the pumped-storage power station with upstream and downstream surge tanks under load reduction disturbance is obtained. The present invention considers the complex hydraulic coupling relationship between the upstream and downstream double surge tanks and establishes a mathematical model of a pumped-storage power station with upstream and downstream double surge tanks due to the problem of hydraulic vibration caused by the hydraulic coupling effect. Further, a method for optimizing the surge tank area parameters of a pumped-storage power station with upstream and downstream double surge tanks is proposed. Considering that the problem of optimizing the surge tank area is essentially a problem of considering the comprehensive benefits of the system, the fitness value is used as the brightness of the firefly, the relative brightness and attraction between each pair of fireflies are calculated, and the movement operation is carried out according to the relative brightness size, so as to update the position and brightness of the firefly. A perturbation step size is added to avoid the firefly falling into the local optimum. The optimization process of the firefly algorithm is simple to operate, requires few parameters to be adjusted, and has excellent performance. Thus, the problem that the existing technology does not consider comprehensively enough and cannot quickly and accurately obtain the optimal combination of the upstream and downstream surge tank areas is solved.

[0131] The above is a method for optimizing the surge tank area of a pumped-storage power station provided by an embodiment of the present invention. The following is a system for optimizing the surge tank area of a pumped-storage power station provided by an embodiment of the present invention.

[0132] Please refer to Figure 5 A system for optimizing the surge tank area of a pumped-storage power station provided by an embodiment of the present invention includes:

[0133] The first construction unit 201 is used to establish a mathematical model of a pumped - storage power station with upper and lower regulating chambers.

[0134] The second construction unit 202 is used to construct decision variables for optimizing the regulating chamber system based on the mathematical model, determine the constraint conditions of the optimization parameters, and establish a fitness objective function for the regulating chamber that is comprehensively optimal for the maximum water - level fluctuation and the attenuation degree of water - level change in the upper and lower regulating chamber systems.

[0135] The solving unit 203 is used to solve for the optimal combination of the areas of the upper and lower regulating chambers by combining the decision variables, the constraint conditions, and the regulating - chamber fitness objective function through the firefly algorithm.

[0136] A regulating - chamber area optimization system for a pumped - storage power station provided by an embodiment of the present invention optimizes the areas of the upper and lower regulating chambers of a pumped - storage power station with upper and lower regulating chambers. First, a mathematical model of a pumped - storage power station with upper and lower regulating chambers is established, and the decision variables, constraint conditions, and objective function for optimizing the water - level fluctuations of the two regulating chambers are determined. The theoretical basis and algorithm flow of the regulating - chamber area optimization research based on the firefly algorithm are analyzed, and the regulating - chamber area optimization research of a certain pumped - storage power station with upper and lower regulating chambers under load - shedding disturbances is carried out, and the optimal combination of the areas of the upper and lower regulating chambers of the pumped - storage power station with upper and lower regulating chambers under load - shedding disturbances is obtained. Considering the complex hydraulic coupling relationship between the upper and lower regulating chambers and the problem of hydraulic vibration caused by the hydraulic coupling effect, the present invention establishes a mathematical model of a pumped - storage power station with upper and lower regulating chambers. Further, a method for optimizing the regulating - chamber area parameters of a pumped - storage power station with upper and lower regulating chambers is proposed. Considering that the regulating - chamber area optimization problem is essentially a problem of comprehensive system benefits, the value of fitness is used as the brightness of the firefly, the relative brightness and attraction between each pair of fireflies are calculated, and movement operations are performed according to the relative brightness, so as to update the positions and brightness of the fireflies. A perturbation step size is added to avoid the fireflies falling into local optima. The optimization process of the firefly algorithm is simple, with few parameters to be adjusted and excellent performance. Thus, the problem that the prior art is not comprehensive enough and cannot quickly and accurately obtain the optimal combination of the areas of the upper and lower regulating chambers is solved.

[0137] Furthermore, an embodiment of the present invention also provides a regulating - chamber area optimization device for a pumped - storage power station. The device includes a processor and a memory:

[0138] The memory is used to store program codes and transmit the program codes to the processor;

[0139] The processor is used to execute the steps of the regulating - chamber area optimization method for the pumped - storage power station as described in the above - mentioned method embodiment according to the instructions in the program codes.

[0140] Furthermore, in the embodiments of the present invention, a computer-readable storage medium is also provided. The computer-readable storage medium is used to store program codes, and the program codes are used to execute the method for optimizing the area of the surge chamber of the pumped storage power station described in the above method embodiments.

[0141] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0142] In several embodiments provided by the present invention, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection can be through some interfaces. The indirect coupling or communication connection of devices or units can be in electrical, mechanical or other forms.

[0143] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place, or can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0144] In addition, in each embodiment of the present invention, the functional units can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0145] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0146] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for optimizing the area of a surge chamber in a pumped storage power station, characterized in that, include: Establish a mathematical model of a pumped storage power station with upstream and downstream double surge chambers; Based on the mathematical model, the decision variables for optimizing the surge chamber system are constructed, the constraints of the optimization parameters are determined, and the surge chamber fitness objective function with comprehensive optimality for the maximum water level fluctuation and water level change attenuation of the upstream and downstream surge chamber systems is established; The optimal combination of upstream and downstream surge chamber areas is obtained by combining the decision variables, the constraint conditions and the surge chamber fitness objective function through the firefly algorithm.

2. The method for optimizing the area of the surge chamber of a pumped storage power station according to claim 1, characterized in that, The mathematical model of the pumped storage power station with a downstream double surge chamber is established, including: The diversion tunnel equation, tailwater tunnel equation, upstream and downstream surge chamber continuity equation, upstream and downstream surge chamber long connecting pipe equation, pressure pipe equation, pump turbine torque and flow equation, generator motor equation and speed governor equation are constructed respectively and combined to obtain the seventh-order state equation of the pumped-storage power station system with upstream and downstream double surge chambers.

3. The method for optimizing the area of the surge chamber of a pumped-storage power station according to claim 2, characterized in that, The expression of the seventh-order state equation is: ； In the formula, is the inertia time constant of the water flow in the pressure pipeline, H0 is the working head of the unit, is the relative working head of the unit, is the relative head loss of the pressure pipeline, is the relative flow rate of the pressure pipeline; are the relative water level fluctuations in the upstream and downstream surge chambers, are the time constants of the upstream and downstream surge chambers, are the inertia time constants of the water flow in the long connecting pipes of the upstream and downstream surge chambers, are the head loss coefficients of the long connecting pipes of the upstream and downstream surge chambers; is the relative value of the piezometric head at the bottom of the upstream and downstream surge chambers, are the initial relative head losses of the intake tunnel and the tailrace tunnel, are the inertia time constants of the water flow in the intake tunnel and the tailrace tunnel, are the relative flow rates of the intake and tailrace tunnels; is the relative value of the piezometric head at the bottom of the upstream and downstream surge chambers, are the initial relative head losses of the intake tunnel and the tailrace tunnel, is the resistance torque of the turbine; is the load self-regulation coefficient, is the inertia time constant of the unit, is the proportional gain of the governor; is the integral gain of the governor, is the torque transfer coefficient of the turbine; is the flow transfer coefficient of the turbine.

4. The method for optimizing the area of the surge chamber of a pumped storage power station according to claim 1, wherein, The decision variables for constructing the surge chamber system optimization include: The parameters that determine the operating stability of the surge chamber are used as decision variables for optimizing the surge chamber system, and the parameters include: an upstream surge chamber area and a downstream surge chamber area.

5. The method for optimizing the area of the surge chamber of a pumped-storage power station according to claim 1, wherein, The constraint conditions for determining the optimization parameters include: The constraints of the optimization parameters are preliminarily determined according to the Thomas section formula, and the constraints include: < <C < <C >0， >0 In the formula, is the cross-sectional area of the upstream surge chamber, is the cross-sectional area of the downstream surge chamber, is the cross-sectional area of the Thoma critical section of the upstream surge chamber, is the cross-sectional area of the Thoma critical section of the downstream surge chamber, C is a given constant, is the attenuation degree of the water level change in the upstream surge chamber, is the attenuation degree of the water level change in the downstream surge chamber.

6. The method for optimizing the surge chamber area of a pumped storage power station according to claim 1, wherein The expression of the surge chamber fitness objective function is: In the formula, is the maximum value of the water level fluctuations in the upstream and downstream surge chambers in the dynamic response of the surge chamber water level; is the attenuation degree of the water level change in the upstream and downstream surge chambers in the dynamic response; is the corresponding weight value.

7. The method for optimizing the surge chamber area of a pumped storage power station according to claim 1, wherein The optimal upstream and downstream surge chamber area combination is obtained by combining the decision variables, the constraint conditions and the surge chamber fitness objective function through the firefly algorithm, including: S11, setting firefly algorithm parameters, initializing firefly groups and firefly positions, including: initializing surge chamber area parameters of a pumped storage power station with upstream and downstream double surge chambers; S12, by applying load disturbance, obtaining the dynamic response of the water level of the upstream and downstream surge chambers, calculating and processing the dynamic response to obtain the maximum value of the water level fluctuation of the upstream and downstream surge chambers and the attenuation of the water level change of the upstream and downstream surge chambers, and then bringing them into the fitness objective function of the surge chamber to obtain the fitness value; S13, taking the fitness value as the brightness of the fireflies, calculating the relative brightness and attraction between each pair of fireflies, and performing a moving operation according to the relative brightness, thereby updating the position and brightness of the fireflies; S14, looping steps S12 and S13 until the preset maximum number of iterations is reached, and outputting an optimal solution, wherein the optimal solution is an optimal combination of upstream and downstream surge chamber areas.

8. A pressure regulating chamber area optimization system for a pumped storage power station, characterized in that, include: The first construction unit is used to establish a mathematical model of a pumped storage power station with upstream and downstream double surge chambers; The second construction unit is used to construct decision variables for optimizing the surge chamber system based on the mathematical model, determine the constraints of the optimization parameters, and establish a surge chamber fitness objective function with comprehensive optimality regarding the maximum value of water level fluctuation and water level change attenuation of the upstream and downstream surge chamber systems; A solving unit is used to combine the decision variables, the constraint conditions and the surge chamber fitness objective function to obtain an optimal upstream and downstream surge chamber area combination through a firefly algorithm.

9. A pressure regulating chamber area optimization device for a pumped storage power station, characterized in that, The device comprises a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the method for optimizing the area of the surge chamber of the pumped-storage power station according to any one of claims 1-7 based on the instructions in the program code.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store program code, and the program code is used to execute the method for optimizing the area of the surge chamber of the pumped-storage power station according to any one of claims 1-7.

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