Adjusting hydroelectric starting and power generation method considering frequency modulation demand and related equipment

Abstract

The invention discloses an adjustable hydroelectric startup and power generation method considering frequency modulation demand and related equipment, through the synergistic effect of hydroelectric constraint and wind power photovoltaic constraint, the frequency modulation potential of each energy source is fully exerted, and the frequency modulation capability of the system is significantly improved; a frequency safety constraint is established, safe and stable frequency operation of the system under different load disturbances is ensured, and the frequency safety problem in the prior art is effectively solved; based on simulation analysis of a scene model, a scientific basis is provided for formulating a reasonable starting principle and a reasonable power generation strategy, and overall optimization scheduling of the water-wind-light coupling system is achieved. The optimal scheduling model takes the minimum operation cost as a target, and the operation cost of the system is reduced while the frequency modulation requirement is met through a reasonable scheduling strategy.

Description

Technical Field

[0001] The present invention relates to the technical field of power generation optimization, and particularly relates to a method for starting up and generating electricity of regulating hydropower considering frequency modulation requirements and related equipment. Background Art

[0002] Under the general trend of global energy transformation, the power systems in many countries and regions around the world are changing towards a high-proportion, extremely high-proportion or even 100% renewable energy system. In this process, new energy generation continuously replaces synchronous units and becomes the main force of power supply. However, this transformation also brings the problem of insufficient system frequency modulation resources, and the frequency safety hidden danger becomes more and more obvious.

[0003] Taking the Sichuan power grid as an example, its hydropower accounts for a high proportion, which provides unique advantages for the frequency modulation control of the system. However, the renewable energy in the Sichuan water-wind-solar base is highly concentrated and far from the load center, resulting in a severe overload problem in the power transmission channels in the renewable energy-rich areas, and the demand for improving the energy frequency modulation ability is extremely urgent. In order to ensure the frequency safety and stability during the optimal dispatching of the water-wind-solar coupling system with a high proportion of hydropower, and at the same time prevent the overload of the transmission channels, it is extremely urgent to study the water-wind-solar coupling optimal dispatching strategy for frequency modulation and section control.

[0004] Hydropower has strong frequency modulation ability and power generation flexibility, and its start-up and shutdown operations will directly affect the regulation ability and frequency modulation ability of the overall system. At present, for the frequency safety problems of the water-wind-solar coupling system with a high proportion, most studies are committed to improving the frequency response ability of wind power and photovoltaic through strategies such as virtual inertia control and load shedding control. However, most of the existing results focus on single energy systems or wind-solar complementary systems, and there is no specific research on sorting out and summarizing the start-up and shutdown principles and power generation strategies of regulating hydropower under frequency modulation requirements.

[0005] In existing research, the literature "Energy Storage Participation in Grid Primary Frequency Regulation Control Strategy under Wind Power Integration" and the literature "Doubly Fed Induction Generator Frequency Control Strategy Combining Overspeed Reserve and Simulated Inertia" proposed that the ways for wind power to participate in frequency regulation mainly include strategies such as virtual inertia control, load shedding control, and virtual droop control. Photovoltaic usually relies on mutual support with power sources with frequency regulation capabilities such as energy storage to meet the frequency regulation requirements and maintain grid frequency stability. For example, the literature "Photovoltaic-Storage Grid-Connected Power Generation Control Technology Based on Virtual Synchronous Generator". At the same time, the literature "Battery energy storage system control for mitigating PV penetration impact on primary frequency control and state-of-charge recovery" studied the control of battery energy storage systems to mitigate the impact of PV access on primary frequency regulation and state-of-charge recovery.

[0006] The literature "Review and Prospect of Power System Inertia Research under High Proportion of Renewable Energy Access" and the literature "Research on Inertia System of Frequency Response in High Proportion Power Electronic Power System" comprehensively summarized, evaluated and prospected the related concepts of power system inertia, such as the relationship between traditional inertia, equivalent inertia and virtual inertia, and the capabilities and ways of different energy sources to participate in frequency regulation. To more accurately evaluate the equivalent inertia of new energy systems, the literature "Evaluation of Equivalent Inertia of New Energy Power System Considering Frequency Distribution Characteristics" established an inertia evaluation method considering frequency distribution characteristics, and obtained the corresponding minimum primary frequency regulation output based on this method. In the research on the optimal scheduling model considering dynamic frequency response, the literature "Stochastic Optimal Scheduling Considering Prediction Error and Frequency Response" mainly studied the stochastic optimal scheduling problem under the access of wind power to the power grid. By considering the prediction error distribution to generate wind power output scenarios, the system dynamic frequency response model was then derived, and the dynamic frequency response constraint was incorporated into the constraint conditions. The proposed method can maintain frequency stability when wind power is connected to the system. The literature "Short-Term Optimal Scheduling Model of Wind-Solar-Hydro Complementary Power Generation Considering Dynamic Frequency Response" considered the dynamic frequency response characteristics of wind, solar and hydro, and proposed a short-term optimal scheduling model of wind-solar-hydro complementary power generation. This model comprehensively considered the dynamic frequency response constraints of wind, solar and hydro, and improved the frequency regulation ability of the system on the premise of maximizing the use of clean energy. Although the existing technologies have achieved certain results in the participation of new energy in frequency regulation and the optimal scheduling model, there are still many deficiencies in the face of the complex requirements of the water-wind-solar coupling system with a high proportion of hydropower, especially in the aspects of regulating hydropower start-stop and power generation strategies. Summary of the Invention

[0007] Based on the problems raised in the above background art, the object of the present invention is to provide a regulating hydropower startup and power generation method considering frequency modulation requirements and related media, which solves the problem that although certain achievements have been made in the prior art in terms of new energy participating in frequency modulation and optimizing the dispatching model, the dispatching problem when the complex requirements of a water-wind-solar coupling system with a high proportion of hydropower cannot be solved yet.

[0008] The present invention is realized through the following technical solutions:

[0009] The first aspect of the present invention provides a regulating hydropower startup and power generation method considering frequency modulation requirements, including the following steps:

[0010] Construct an optimal dispatching model; wherein, the optimal dispatching model establishes an objective function with the minimum operation cost of hydropower, wind power, and photovoltaic power as the goal;

[0011] Consider the hydropower switch-on and -off to establish hydropower constraints, consider the frequency modulation reserve capacity to establish wind power and photovoltaic constraints, consider the frequency security under different load disturbances to establish frequency security constraints, and use the hydropower constraints, the wind power and photovoltaic constraints, and the frequency security constraints to constrain the objective function;

[0012] Based on different load fluctuations and disturbances, establish a scenario model, obtain the scenario frequency modulation requirements of the scenario model, use the constrained optimal dispatching model to perform simulations according to the scenario frequency modulation requirements, obtain simulation results, and determine the startup principle and power generation strategy according to the simulation results.

[0013] In the above technical solution, first of all, this method constructs an optimal dispatching model, wherein the optimal dispatching model establishes an objective function with the minimum operation cost of hydropower, wind power, and photovoltaic power as the goal.

[0014] Secondly, to solve the problem of insufficient frequency modulation resources, this method establishes hydropower constraint conditions by considering the characteristics of hydropower switch-on and -off, gives full play to the frequency modulation potential of hydropower, and ensures that hydropower can effectively participate in system frequency modulation under different operating states, thereby solving the problem of insufficient frequency modulation resources. Consider the frequency modulation reserve capacity and establish wind power and photovoltaic constraint conditions, so that wind power and photovoltaic power can provide frequency modulation support for the system while meeting their own operating characteristics, to enrich the frequency modulation resources. The optimal dispatching model comprehensively considers the operating characteristics of hydropower, wind power, and photovoltaic power, and realizes the overall optimal dispatching of the water-wind-solar coupling system through the collaborative optimization of the objective function and the constraint conditions. This model not only considers the operating costs of various energy sources, but also ensures the mutual cooperation of various energy sources during frequency modulation through constraint conditions, solving the problem of the lack of comprehensive optimization strategies in the prior art.

[0015] Furthermore, the method also introduces frequency security constraints, and establishes frequency security constraints according to the frequency security requirements under different load disturbances to ensure frequency security under different load disturbances. This constraint condition can ensure that the frequency of the system always remains within the safe range under various load fluctuations and disturbances, thus effectively guaranteeing the safe and stable operation of the system frequency.

[0016] Based on different load fluctuations and disturbances, a scenario model is established. There are corresponding frequency regulation requirements in different scenarios. Obtain the frequency regulation requirements in a specific scenario, and perform simulation training on the optimized scheduling model after constraint according to this frequency regulation requirement to obtain 14 groups of simulation results such as energy output, hydropower startup and shutdown conditions, and system equivalent inertia constant. Summarize and analyze according to this simulation result to determine the startup principle and power generation strategy, and then verify the performance and adaptability of the optimized scheduling model in different scenarios.

[0017] In an alternative embodiment, a target function is established with the minimum operation cost of hydropower, wind power and photovoltaic as the target, including:

[0018]

[0019] In the above formula, is the total system operation cost, is the total cost of hydropower start-stop and water abandonment, is the penalty cost for wind and light abandonment, is the total operation cost of wind power, photovoltaic power and hydropower, is the penalty cost for load shedding, is the system reserve cost, N h 、N w 、N pv are the number of hydropower stations, the number of wind power stations and the number of photovoltaic power stations respectively, c h 、c on 、c off are the water abandonment penalty coefficient, the startup cost and the shutdown cost of hydropower respectively, ΔQ ht 、N hbe 、N hst are the water abandonment volume, the startup times and the shutdown times of hydropower station h at time t respectively, c w 、c pv are the wind abandonment penalty coefficient and the light abandonment penalty coefficient of wind power and photovoltaic power respectively, are the wind and photovoltaic power abandonment volumes at time t of wind power and photovoltaic power stations respectively, c run,pv 、c run,w 、c run,h are the operation cost coefficients of photovoltaic power, wind power and hydropower respectively, P pv,t 、P w,t 、P h,tare the power outputs of the PV power station, wind farm, and hydropower station at time t, respectively, c l is the loss-of-load penalty factor, is the amount of load loss at time t, where c b is the system reserve cost factor, r h are the frequency regulation reserve capacities of PV and wind power at time t and the reserve capacity of hydropower at time t, respectively.

[0020] In an alternative embodiment, considering the start-up and shutdown of hydropower to establish hydropower constraints, including:

[0021] Obtain the power generation efficiency, head, and power generation flow rate of the hydropower station, and determine the conversion function by synthesizing the power generation efficiency, the head, and the power generation flow rate;

[0022] Based on the conversion function, constrain the upper and lower limits of hydropower processing and the up-ramp of hydropower to generate the first hydropower constraint;

[0023] Based on the power generation flow rate, constrain the power generation flow rate and the amount of abandoned power of the hydropower station to generate the second hydropower constraint;

[0024] Constrain the upper and lower limits, initial and final reservoir capacities, and reservoir capacity balance of the hydropower station reservoir to generate the third hydropower constraint;

[0025] Synthesize the first hydropower constraint, the second hydropower constraint, and the third hydropower constraint to obtain the comprehensive hydropower constraint. In an alternative embodiment, the first hydropower constraint includes:

[0026] P h,t = g h η h Q h,t H h,t

[0027]

[0028] In the above formula, P h,t is the power generation power of hydropower station h at time t; g h is the hydropower conversion coefficient; η h is the power generation efficiency of hydropower station h; Q h,t is the power generation flow rate of hydropower station h at time t; H h,t is the average head of hydropower station h at time t; I h,t is the state variable of hydropower start-stop; are the minimum and maximum power outputs of hydropower station h, respectively; and are the maximum down-ramp power and maximum up-ramp power of hydropower station h, respectively;

[0029] The second hydropower constraint includes:

[0030]

[0031] In the above formula, Q h,t is the power generation flow of hydropower station h at time t; is the minimum power generation flow; is the maximum power generation flow; ΔQ h,t is the water abandonment of the hydropower station;

[0032] The third hydropower constraint described above includes:

[0033]

[0034] In the above formula, V h,t is the reservoir capacity of hydropower station h at time t, are the minimum and maximum reservoir capacities of hydropower station h respectively, N T is the final time of the power and electricity balance analysis, v h,0 , represent the initial reservoir capacity and the reservoir capacity at the final time of hydropower station h respectively; is the natural inflow of hydropower station h at time t R h,t and the downstream discharge flow of the upper-level hydropower station in the same basin of the sum.

[0035] In an alternative embodiment, considering the frequency regulation reserve capacity to establish the wind power and photovoltaic constraints, including:

[0036]

[0037] In the above formula, the outputs of wind power and photovoltaic are P w,t and P pv,t , represent the upper limits of the available power generation of wind power and photovoltaic power plants at time t respectively, are the abandoned power amounts of wind power and photovoltaic at time t respectively, are the frequency regulation reserve capacities required for wind power and photovoltaic to provide frequency regulation capabilities at time t respectively.

[0038] In an alternative embodiment, considering the frequency safety under different load disturbances to establish the frequency safety constraints, including:

[0039] The frequency response includes an inertial response stage and a primary frequency regulation stage;

[0040] Calculate the inertia of the hydro synchronous motor and the virtual inertia of the wind power station, and combine the inertia and the virtual inertia to obtain the system equivalent inertia;

[0041] Constrain the system equivalent inertia in the inertial response stage to generate the first frequency constraint;

[0042] Obtain the hydropower reserve capacity and the wind power and photovoltaic reserve capacity, and combine the hydropower reserve capacity and the wind power and photovoltaic reserve capacity to obtain the system reserve capacity;

[0043] Constrain the system reserve capacity in the primary frequency regulation stage to generate a second frequency constraint;

[0044] Combine the first frequency constraint and the second frequency constraint to obtain a frequency security constraint.

[0045] In an alternative embodiment, the first frequency constraint includes:

[0046]

[0047] In the above formula, H sys is the system equivalent inertia, ΔP t L is the load change at time t, f N is the rated frequency of the system, RoCoF max is the maximum frequency change rate;

[0048] The second frequency constraint includes:

[0049]

[0050] In the above formula, P b is the system reserve capacity, f min is the minimum allowable frequency after system disturbance.

[0051] It should be noted that from the perspective of inertia, the inertia generated by the hydro-synchronous motor is:

[0052]

[0053] Among them, E h is the inertia that the hydro-synchronous motor can provide, H h is the inertia constant of hydropower station h, S h is the rated capacity of hydropower station h.

[0054] The second aspect of the present invention provides a regulated hydropower startup and power generation system considering frequency regulation requirements, including:

[0055] A target construction module for constructing an optimal scheduling model; wherein, the optimal scheduling model establishes an objective function with the minimum cost of hydropower, wind power, and photovoltaic operation as the target;

[0056] A constraint construction module is used to establish hydropower constraints by considering the startup and shutdown of hydropower units, establish wind and photovoltaic constraints by considering the frequency regulation reserve capacity, establish frequency security constraints by considering the frequency security under different load disturbances, and use the hydropower constraints, the wind and photovoltaic constraints, and the frequency security constraints to constrain the objective function;

[0057] A scenario simulation module is used to establish a scenario model based on different load fluctuations and disturbances, obtain the scenario frequency regulation requirements of the scenario model, perform simulations using the constrained optimal dispatch model according to the scenario frequency regulation requirements, obtain simulation results, and determine the startup principle and power generation strategy according to the simulation results.

[0058] The third aspect of the present invention provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements a method for regulating hydropower startup and power generation considering frequency regulation requirements.

[0059] The fourth aspect of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements a method for regulating hydropower startup and power generation considering frequency regulation requirements.

[0060] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0061] 1. Through the synergistic effect of hydropower constraints and wind and photovoltaic constraints, the frequency regulation potential of each energy source is fully exerted, significantly improving the frequency regulation ability of the system;

[0062] 2. Establishing frequency security constraints ensures the safe and stable operation of the system under different load disturbances, effectively solving the frequency security problems in the prior art;

[0063] 3. Based on the simulation analysis of the scenario model, it provides a scientific basis for formulating reasonable startup principles and power generation strategies, realizing the overall optimal dispatch of the water-wind-solar coupling system;

[0064] 4. The optimal dispatch model aims at minimizing the operation cost. Through reasonable dispatch strategies, while meeting the frequency regulation requirements, it reduces the operation cost of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings. In the drawings:

[0066] Figure 1 Schematic flow chart of the regulative hydropower startup and power generation method considering frequency modulation requirements provided in Embodiment 1 of the present invention;

[0067] Figure 2 Schematic structural diagram of an electronic device provided in Embodiment 3 of the present invention. Detailed implementation manners

[0068] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments and drawings. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0069] Embodiment 1

[0070] Figure 1 Schematic flow chart of the regulative hydropower startup and power generation method considering frequency modulation requirements provided in Embodiment 1 of the present invention, as Figure 1 shown, the regulative hydropower startup and power generation method considering frequency modulation requirements includes the following steps:

[0071] Construct an optimal scheduling model; wherein, the optimal scheduling model establishes an objective function with the minimum cost of hydropower, wind power and photovoltaic operation as the objective;

[0072] Consider the hydropower startup and shutdown to establish hydropower constraints, consider the frequency modulation reserve capacity to establish wind power and photovoltaic constraints, consider the frequency security under different load disturbances to establish frequency security constraints, and use the hydropower constraints, the wind power and photovoltaic constraints and the frequency security constraints to constrain the objective function;

[0073] Based on different load fluctuations and disturbances, establish a scenario model, obtain the scenario frequency modulation requirements of the scenario model, perform simulation according to the scenario frequency modulation requirements using the constrained optimal scheduling model, obtain a simulation result, and determine the startup principle and power generation strategy according to the simulation result.

[0074] It should be noted that, first of all, this method constructs an optimal scheduling model, wherein the optimal scheduling model establishes an objective function with the minimum cost of hydropower, wind power and photovoltaic operation as the objective.

[0075] Secondly, to solve the problem of insufficient frequency modulation resources, this method establishes hydropower constraint conditions by considering the characteristics of hydropower start-stop, gives full play to the frequency modulation potential of hydropower, and ensures that hydropower can effectively participate in system frequency modulation under different operating states, thus solving the problem of insufficient frequency modulation resources. Considering the frequency modulation reserve capacity, wind power and photovoltaic constraint conditions are established, so that wind power and photovoltaic can provide frequency modulation support for the system while meeting their own operating characteristics, to enrich the frequency modulation resources. The optimized dispatch model comprehensively considers the operating characteristics of hydropower, wind power and photovoltaic, and realizes the overall optimized dispatch of the water-wind-solar coupling system through the coordinated optimization of the objective function and constraint conditions. This model not only considers the operating costs of various energy sources, but also ensures the mutual cooperation of various energy sources during frequency modulation through constraint conditions, solving the problem of lack of comprehensive optimization strategies in the existing technology.

[0076] Furthermore, this method also introduces frequency security constraints, and establishes frequency security constraints according to the frequency security requirements under different load disturbances to ensure frequency security under different load disturbances. This constraint condition can ensure that the frequency of the system always remains within a safe range under various load fluctuations and disturbances, thus effectively guaranteeing the safe and stable operation of the system frequency.

[0077] Based on different load fluctuations and disturbances, a scenario model is established. There are corresponding frequency modulation requirements in different scenarios. The frequency modulation requirements in a specific scenario are obtained, and the optimized dispatch model after constraint is simulated and trained according to this frequency modulation requirement. Fourteen groups of simulation results such as energy output, hydropower start-stop conditions, and system equivalent inertia constant are obtained. Summary and analysis are carried out according to this simulation result to determine the start-up principle and power generation strategy, and then verify the performance and adaptability of the optimized dispatch model in different scenarios.

[0078] In an optional embodiment, an objective function is established with the minimum operating cost of hydropower, wind power and photovoltaic as the goal, including:

[0079]

[0080] In the above formula, is the total system operating cost, is the total cost of hydropower start-stop and water abandonment, is the penalty cost for wind and light abandonment, is the total operating cost of wind power, photovoltaic and hydropower, is the penalty cost for load shedding, is the system reserve cost, N h 、N w 、N pv are the numbers of hydropower stations, wind power stations and photovoltaic power stations respectively, c h 、c on 、c offare the penalty coefficient for curtailed hydropower, the start-up cost and the shut-down cost of hydropower, respectively, and ΔQ ht , N hbe , N hst are the curtailed water volume, the number of start-ups and the number of shut-downs of hydropower station h at time t, respectively, and c w , c pv are the penalty coefficient for curtailed wind power and the penalty coefficient for curtailed photovoltaic power of wind power and photovoltaic power, respectively, are the curtailed power of wind power and photovoltaic power station at time t, respectively, and c run,pv , c run,w , c run,h are the operating cost coefficients of photovoltaic, wind power and hydropower, respectively, and P pv,t , P w,t , P h,t are the power outputs of photovoltaic power station, wind farm and hydropower station at time t, respectively, and c l is the penalty coefficient for load shedding, is the load shedding volume at time t, and among them, c b is the system reserve cost coefficient, r h are the frequency regulation reserve capacities of photovoltaic and wind power at time t and the reserve capacity of hydropower at time t, respectively.

[0081] In an alternative embodiment, considering the start-up and shut-down of hydropower, hydropower constraints are established, including:

[0082] Obtain the power generation efficiency, head and power generation flow rate of the hydropower station, and determine the conversion function by synthesizing the power generation efficiency, the head and the power generation flow rate;

[0083] Based on the conversion function, constraints on the upper and lower limits of hydropower and the upward ramp of hydropower are imposed to generate the first hydropower constraint;

[0084] Based on the power generation flow rate, constraints on the power generation flow rate and the curtailed power of the hydropower station are imposed to generate the second hydropower constraint;

[0085] Impose upper and lower limit constraints, initial and final reservoir capacity constraints and reservoir capacity balance constraints on the reservoir capacity of the hydropower station to generate the third hydropower constraint;

[0086] Synthesize the first hydropower constraint, the second hydropower constraint and the third hydropower constraint to obtain the comprehensive hydropower constraint.

[0087] It should be noted that the power generation power of the hydropower station is mainly determined by the power generation efficiency η h , head H h,t and power generation flow rate Q h,tDetermined by three factors, the non-linear relationship between power generation and flow can be quantified through a conversion function. On the premise of determining the power generation of a hydropower station, in order to save the operation cost of hydropower and considering the start-stop of hydropower, it is necessary to constrain the upper and lower limits of hydropower output and the up and down ramps of hydropower. At the same time, hydropower stations will face constraints on power generation flow and the amount of abandoned electricity. For hydropower stations with reservoirs, their reservoir capacities will also be subject to upper and lower limits, initial and final reservoir capacity constraints, and reservoir capacity balance constraints.

[0088] Therefore, based on the above three considerations, in this embodiment, the first hydropower constraint, the second hydropower constraint, and the third hydropower constraint are established respectively based on the above conditions, and the three are combined to obtain the final comprehensive hydropower constraint required by this embodiment.

[0089] In an alternative embodiment, the first hydropower constraint includes:

[0090] P h,t =g h η h Q h,t H h,t

[0091]

[0092] In the above formula, P h,t is the power generation of hydropower station h at time t; g h is the hydropower conversion coefficient; η h is the power generation efficiency of hydropower station h; Q h,t is the power generation flow of hydropower station h at time t; H h,t is the average head of hydropower station h at time t; I h,t is the state variable of hydropower start-stop; are respectively the minimum and maximum outputs of hydropower station h; and are respectively the maximum down-ramp power and the maximum up-ramp power of hydropower station h;

[0093] The second hydropower constraint includes:

[0094]

[0095] In the above formula, Q h,t is the power generation flow of hydropower station h at time t; is the minimum power generation flow; is the maximum power generation flow; ΔQ h,t is the abandoned water of the hydropower station;

[0096] The third hydropower constraint includes:

[0097]

[0098] In the above formula, V h,t is the reservoir capacity of hydropower station h at time t, are the minimum and maximum reservoir capacities of hydropower station h respectively, N T is the final time for the power and electricity balance analysis, v h,0 、 represent the initial reservoir capacity and the reservoir capacity at the final time of hydropower station h respectively; is the natural inflow of water of hydropower station h at time t, R h,t and the downstream discharge of the upper-level hydropower station in the same basin is the sum.

[0099] It should be noted that I h,t is the state variable of hydropower start-stop. When hydropower station h starts at time t, I h,t = 1. When hydropower station h is in the shutdown state at time t, I h,t = 0. ΔQ h,t is the water abandonment of the hydropower station, and it is restricted to be greater than or equal to 0. v h,0 、 are both constants. represents the water inflow of hydropower station h at time t, where has a certain time delay τ h , and for adjustable hydropower stations,

[0100] Furthermore, the regulation ability of the hydropower station is relatively strong, and it also has reserve capacity. In this embodiment, the reserve capacity is:

[0101]

[0102] Among them, N h is the number of hydropower stations, r h is the total reserve capacity that all hydropower stations can provide at time t.

[0103] It should be noted that the number of start-up and shutdown times of the hydropower station in a day is limited.

[0104] In an alternative embodiment, considering the frequency regulation reserve capacity, wind power and photovoltaic constraints are established, including:

[0105]

[0106] In the above formula, the outputs of wind power and photovoltaic are P w,t and P pv,t , represent the upper limits of the available power generation of wind power and photovoltaic power stations at time t respectively, are the abandoned power quantities of wind power and photovoltaic at time t respectively, The frequency regulation reserve capacities required for wind power and photovoltaic power to provide frequency regulation capabilities at time t, respectively.

[0107] Among them, the wind power and photovoltaic constraints proposed in the embodiments of the present invention are obtained by considering the regulation margins required for wind power and photovoltaic power to provide frequency regulation capabilities, and constraining the upper and lower limits of the output power of wind power and photovoltaic power, the curtailed power, and the regulation margin. By introducing the frequency regulation reserve capacity, the curtailed power, and the power upper limit, it is ensured that wind power and photovoltaic power meet the system frequency regulation requirements at a certain cost in the optimal dispatch.

[0108] In an alternative embodiment, a frequency security constraint is established considering the frequency security under different load disturbances, including:

[0109] The frequency response includes an inertia response stage and a primary frequency regulation stage;

[0110] Calculate the inertia of the hydroelectric synchronous motor and the virtual inertia of the wind power station, and synthesize the inertia and the virtual inertia to obtain the system equivalent inertia;

[0111] Constrain the system equivalent inertia in the inertia response stage to generate a first frequency constraint;

[0112] Obtain the hydroelectric reserve capacity and the wind power and photovoltaic reserve capacity, and synthesize the hydroelectric reserve capacity and the wind power and photovoltaic reserve capacity to obtain the system reserve capacity;

[0113] Constrain the system reserve capacity in the primary frequency regulation stage to generate a second frequency constraint;

[0114] Synthesize the first frequency constraint and the second frequency constraint to obtain the frequency security constraint.

[0115] It should be noted that the stages involved in the frequency response include the inertia response stage, the primary frequency regulation stage, and the secondary frequency regulation stage. Usually, the first two stages play a decisive role in ensuring frequency stability. Therefore, it is crucial to pay attention to the frequency support capabilities of the inertia response stage and the primary frequency regulation stage for optimizing the control operation of the power system. The objects participating in frequency regulation in this part include the synchronous motors of hydropower, which can provide traditional inertia, and wind power and photovoltaic power stations, which can participate in frequency regulation through advanced control strategies, thereby providing virtual inertia and primary frequency regulation reserve capacity.

[0116] In an alternative embodiment, the first frequency constraint includes:

[0117]

[0118] In the above formula, H sys is the system equivalent inertia, ΔP t L is the load change at time t, fN is the rated frequency of the system, RoCoF max is the maximum rate of frequency change;

[0119] The second frequency constraint includes:

[0120]

[0121] In the above formula, P b is the system reserve capacity, f min is the minimum allowable frequency after system disturbance.

[0122] It should be noted that from the perspective of inertia, the inertia generated by the hydro-synchronous motor is:

[0123]

[0124] Among them, E h is the inertia that the hydro-synchronous motor can provide, H h is the inertia constant of hydropower station h, S h is the rated capacity of hydropower station h.

[0125] The virtual inertia that wind power can provide can be calculated by the following formula

[0126] E vir,w = H vir,w S vir,w

[0127] Among them, H vir,w is the virtual inertia constant of the wind farm, S vir,w is the rated capacity of wind power, E vir,w is the energy that the wind farm can provide to respond to frequency changes, which is related to its own inherent inertia and the angular velocity of the fan before frequency change.

[0128] In summary, the system equivalent inertia H sys is:

[0129] H sys = E h + E vir,w

[0130] Define the maximum rate of frequency change as RoCoF max , exceeding this rate of frequency change, it is very likely that the system frequency cannot recover.

[0131] Therefore, to ensure frequency safety, the system equivalent inertia in the inertial response stage is constrained.

[0132] Furthermore, the actual equivalent inertia constant h of the system sys can be obtained by h sys = H sys / Ssys is calculated, where S sys is the rated capacity of the power system.

[0133] Furthermore, about 4 s - 10 s after the load disturbance occurs in the system is the primary frequency regulation stage. In this stage, the frequency changes from decreasing to slowly increasing, and the generator starts to inject more power into the system to balance the load demand. What plays a decisive role in this stage is the primary frequency regulation reserve capacity of the synchronous generator sets within the system. The mechanical power of the units gradually increases, reducing the active power difference, and the system frequency begins to rise.

[0134] The inertia that a synchronous motor can provide is the kinetic energy stored in the rotor, and its specific expression is:

[0135]

[0136] Among them, J is the moment of inertia, obtained by J = ∫r 2 dm, r is the radius of rotation, and m is the mass of the rigid body; ω n is the rated angular velocity of the generator rotor.

[0137] The inertia constant is a quantity representing the inertia level of the synchronous motor rotor, with the unit of s, and can be obtained through the following formula:

[0138]

[0139] Among them, S N is the rated capacity of the generator set. This formula represents the time that the kinetic energy stored in the rotor can be consumed by a load equal to the generator rated capacity, so it can be used as a reference for evaluating the inertial response ability.

[0140] With the improvement of control strategies, new energy also has the ability to provide virtual inertia and primary frequency regulation support, and its virtual inertia constant is:

[0141]

[0142] Among them, H vir is the virtual inertia constant, E vir is the energy that various new energy power generation devices can provide for responding to frequency changes, and S vir is the rated capacity of the power conversion device.

[0143] Existing research shows that wind power can provide virtual inertia and has primary frequency regulation ability, and photovoltaic has primary frequency regulation ability. In this system, hydropower provides primary frequency regulation ability through the reserve capacity r h and wind power and photovoltaic respectively provide primary frequency regulation ability through the frequency regulation reserve capacity Therefore, the reserve capacity that the system can provide is:

[0144]

[0145] To ensure the stability of the system frequency, the system reserve capacity in the primary frequency regulation stage is constrained.

[0146] Furthermore, the constraints on the objective function also include the system power and energy balance constraint. Among them, the system power and energy balance constraint requires that the power system should satisfy the load balance at each moment, that is:

[0147]

[0148] In the above formula, P t L is the system load at time t.

[0149] Furthermore, the sub-embodiment considers 3 typical scenarios with different load demands for the scenario model. Under each scenario, 2 - 3 typical days are defined according to different wind and light fluctuations, and 2 kinds of load disturbance situations are considered for each typical scenario - typical day.

[0150] Among them, the typical scenarios in the scenario model are shown in Table 1 below:

[0151] Table 1 Analysis of 2 kinds of load disturbance situations for typical scenarios - typical days with different load demands

[0152]

[0153]

[0154] Based on the typical scenarios in Table 1, determine their scenario frequency regulation requirements, and use the optimized scheduling model after constraints for simulation to obtain the simulation results. Summarize and analyze various operation results under different load demands, different wind and light fluctuations, and different load disturbances, and further obtain the starting principle and power generation strategy of the regulating hydropower station, as shown in Table 2 below:

[0155] Table 2 Starting principle and power generation strategy of the regulating hydropower station

[0156]

[0157] In summary, the optimal power generation strategy can be obtained through the operation of existing algorithms. The start-stop of hydropower is comprehensively affected by load demand, fluctuations in wind and light, and the disturbance situation of the load. The equivalent inertia required by the system restricts the minimum starting capacity of hydropower. At the same time, load demand also affects the start-stop of hydropower. In the case of high load demand, the load demand is the main factor, and the frequency regulation demand is used as the minimum start-stop constraint of hydropower. The start-stop cost and the start-stop times constraint of hydropower, that is, the unit status, will also indirectly affect the start-stop status of hydropower. The start-stop situation of hydropower will first meet the unit status, and under the condition of minimizing the cost, start or stop to meet the frequency regulation and load demand.

[0158] In this embodiment, with the goal of minimizing the global operation cost, through the simulation of different typical scenarios and different typical days, the optimal hydropower generation strategy under different typical days is obtained and the hydropower start-stop principle is summarized. That is, the start-stop of hydropower should not only meet the load demand, but also meet the frequency regulation demand. In the case of high load demand, the load demand is the main factor, and the frequency regulation demand is used as the minimum start-stop constraint of hydropower. The start-stop cost and the start-stop times constraint of hydropower, that is, the unit status, will also indirectly affect the start-stop status of hydropower. The start-stop situation of hydropower will first meet the unit status, and under the condition of minimizing the cost, start or stop to meet the frequency regulation and load demand.

[0159] Embodiment 2

[0160] Embodiment 2 of the present invention provides a regulating hydropower start-up and power generation system considering frequency regulation demand, including:

[0161] A target construction module for constructing an optimal scheduling model; wherein, the optimal scheduling model establishes an objective function with the minimum cost of hydropower, wind power and photovoltaic operation as the target;

[0162] A constraint construction module for considering the start-stop of hydropower to establish hydropower constraints, considering the frequency regulation reserve capacity to establish wind power and photovoltaic constraints, considering the frequency safety under different load disturbances to establish frequency safety constraints, and using the hydropower constraints, the wind power and photovoltaic constraints and the frequency safety constraints to constrain the objective function;

[0163] A scenario simulation module for establishing a scenario model based on different load fluctuations and disturbances, obtaining the scenario frequency regulation demand of the scenario model, performing simulation according to the scenario frequency regulation demand using the constrained optimal scheduling model, obtaining a simulation result, and determining the start-up principle and power generation strategy according to the simulation result.

[0164] Embodiment 3

[0165] Figure 2 The structural schematic diagram of an electronic device provided for Embodiment 3 of the present invention is as Figure 2As shown, the electronic device includes a processor 21, a memory 22, an input device 23, and an output device 24; the number of processors 21 in the computer device can be one or more, Figure 2 and one processor 21 is taken as an example herein; the processor 21, the memory 22, the input device 23, and the output device 24 in the electronic device can be connected through a bus or other means, Figure 2 and connection through a bus is taken as an example herein.

[0166] The memory 22, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules. The processor 21 executes various functional applications and data processing of the electronic device by running the software programs, instructions, and modules stored in the memory 22, that is, implements the regulated hydropower startup and power generation method considering frequency modulation requirements in Embodiment 1.

[0167] The memory 22 mainly includes a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the terminal, etc. In addition, the memory 22 can include high-speed random access memory, and can also include non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices. In some instances, the memory 22 can further include a memory remotely set relative to the processor 21, and these remote memories can be connected to the electronic device through a network. Examples of the above network include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0168] The input device 23 can be used to receive user input such as an id and a password, etc. The output device 24 is used to output a network configuration page.

[0169] Embodiment 4

[0170] Embodiment 4 of the present invention further provides a computer-readable storage medium, and the computer-executable instructions are used to implement the regulated hydropower startup and power generation method considering frequency modulation requirements as provided in Embodiment 1 when executed by a computer processor.

[0171] A storage medium containing computer-executable instructions provided by the embodiments of the present invention, the computer-executable instructions thereof are not limited to the method operations provided in Embodiment 1, and can also execute relevant operations in the regulated hydropower startup and power generation method considering frequency modulation requirements provided in any embodiment of the present invention.

[0172] The specific embodiments described above have further elaborated on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is only for the specific embodiments of the present invention and is not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for regulating hydropower startup and power generation considering frequency regulation requirements, characterized in that: The steps include: Constructing an optimization dispatching model; wherein the optimization dispatching model establishes an objective function with the minimum cost of hydropower, wind power and photovoltaic operation as the goal; Considering the hydropower on / off to establish hydropower constraints, considering the frequency regulation reserve capacity to establish wind power photovoltaic constraints, considering the frequency security under different load disturbances to establish frequency security constraints, and using the hydropower constraints, the wind power photovoltaic constraints and the frequency security constraints to constrain the objective function; A scenario model is established based on different load fluctuations and disturbances, the scenario frequency regulation demand of the scenario model is obtained, simulation is performed using the constrained optimization scheduling model according to the scenario frequency regulation demand, simulation results are obtained, and the startup principle and power generation strategy are determined according to the simulation results.

2. The method for regulating hydropower startup and power generation considering frequency regulation requirements according to claim 1, characterized in that: The objective function is established with the minimum cost of hydropower, wind power and photovoltaic operation as the goal, including: In the above formula, is the total system operating cost, is the total cost of hydropower startup and shutdown and water abandonment, Penalty costs for wind and solar curtailment, is the total operating cost of wind power, photovoltaic power and hydropower, is the load loss penalty cost, is the system backup cost, N h 、N w 、N pv are the number of hydropower stations, wind power stations and photovoltaic power stations respectively, c h 、c on 、c off are the hydropower abandonment penalty coefficient, hydropower startup cost and shutdown cost, ΔQ ht 、N hbe 、N hst are the amount of water abandoned, the number of startups and shutdowns of hydropower station h at time t, respectively, w 、c pv are the wind power abandonment penalty coefficient and photovoltaic abandonment penalty coefficient respectively, are the abandoned power of wind power and photovoltaic power station at time t, c run,pv 、c run,w 、c run,h are the operating cost coefficients of photovoltaic power, wind power and hydropower respectively, P pv,t , P w,t , P h,t are the outputs of photovoltaic power station, wind farm and hydropower station at time t, c l is the load loss penalty coefficient, is the load loss at time t, where c b is the system backup cost coefficient, r h They are the frequency regulation reserve capacity of photovoltaic power and wind power at time t, and the reserve capacity of hydropower at time t.

3. The method for regulating hydropower startup and power generation considering frequency regulation requirements according to claim 1, characterized in that: Consider water and electricity switching and establish water and electricity constraints, including: Acquire the power generation efficiency, water head and power generation flow of the hydropower station, and determine a conversion function by combining the power generation efficiency, the water head and the power generation flow; Based on the conversion function, the upper and lower limits of hydropower processing and the ramp-up of hydropower are constrained to generate a first hydropower constraint; Based on the power generation flow, constraining the power generation flow and the amount of abandoned electricity of the hydropower station to generate a second hydropower constraint; The upper and lower limit constraints, initial and final storage capacity constraints and storage capacity balance constraints are imposed on the storage capacity of the hydropower station to generate the third hydropower constraint; The first hydropower constraint, the second hydropower constraint and the third hydropower constraint are integrated to obtain a comprehensive hydropower constraint.

4. The method for regulating hydropower startup and power generation considering frequency regulation requirements according to claim 3 is characterized in that: The first hydropower constraint includes: P.S h,t g h η h Q h,t H h,t In the above formula, P h,t is the power generation of hydropower station h at time t; g h is the hydropower conversion coefficient; η h is the power generation efficiency of the hydropower station h; Q h,t is the power generation flow of hydropower station h at time t; H h,t is the average water head of the hydropower station h at time t; I h,t It is the state variable of hydropower start and stop; are the minimum and maximum outputs of the hydropower station h, respectively; and are the maximum down-ramp power and maximum up-ramp power of the hydropower station h, respectively; The second hydropower constraint includes: In the above formula, Q h,t is the power generation flow of hydropower station h at time t; is the minimum power generation flow; is the maximum power generation flow; ΔQ h,t discarding water for hydroelectric power stations; The third hydropower constraint includes: In the above formula, V h,t is the storage capacity of hydropower station h at time t, are the minimum and maximum storage capacities of the hydropower station h, N T is the final moment of the power balance analysis, v h,0 , They represent the initial storage capacity and final storage capacity of the hydropower station h respectively; R is the natural water inflow of hydropower station h at time t h,t and the downstream flow of the upper-level hydropower station in the same basin The sum of .

5. The method for regulating hydropower startup and power generation considering frequency regulation requirements according to claim 1, characterized in that: Consider frequency regulation reserve capacity to establish wind power and photovoltaic constraints, including: In the above formula, the output of wind power and photovoltaic power are P w,t and P pv,t , They represent the upper limits of the power that can be generated by wind power and photovoltaic power stations at time t, are the abandoned power of wind power and photovoltaic power at time t, The frequency regulation reserve capacities required for wind power and photovoltaic power to provide frequency regulation capabilities at time t respectively.

6. The method for regulating hydropower startup and power generation considering frequency regulation requirements according to claim 1, characterized in that: Considering the frequency security under different load disturbances, frequency security constraints are established, including: The frequency response includes the inertial response stage and the primary frequency modulation stage; Calculating the inertia of the hydropower synchronous motor and the virtual inertia of the wind power station, and combining the inertia and the virtual inertia to obtain the system equivalent inertia; constraining the system equivalent inertia in the inertial response phase to generate a first frequency constraint; Obtaining hydropower reserve capacity and wind power and photovoltaic reserve capacity, and combining the hydropower reserve capacity and the wind power and photovoltaic reserve capacity to obtain system reserve capacity; constraining the system spare capacity in the primary frequency modulation stage to generate a second frequency constraint; The first frequency constraint and the second frequency constraint are combined to obtain a frequency safety constraint.

7. The method for regulating hydropower startup and power generation considering frequency regulation requirements according to claim 6, characterized in that: The first frequency constraint includes: In the above formula, H sys is the system equivalent inertia, ΔP t L is the load change at time t, f N is the rated frequency of the system, RoCoF max is the maximum frequency change rate; The second frequency constraint includes: In the above formula, P b is the system spare capacity, f min is the minimum allowable frequency after the system is disturbed.

8. A regulating hydropower startup and power generation system considering frequency regulation needs, characterized in that: include: A target building module is used to build an optimization scheduling model; wherein the optimization scheduling model establishes an objective function with the minimum cost of hydropower, wind power and photovoltaic operation as the goal; A constraint building module is used to establish hydropower constraints by considering hydropower on / off, establish wind power photovoltaic constraints by considering frequency regulation reserve capacity, establish frequency security constraints by considering frequency security under different load disturbances, and constrain the objective function by using the hydropower constraints, the wind power photovoltaic constraints and the frequency security constraints; The scenario simulation module is used to establish a scenario model based on different load fluctuations and disturbances, obtain the scenario frequency regulation demand of the scenario model, simulate using the constrained optimization scheduling model according to the scenario frequency regulation demand, obtain simulation results, and determine the startup principle and power generation strategy according to the simulation results.

9. An electronic device, characterized in that: It includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the regulatory hydropower startup and power generation method considering the frequency regulation demand as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for regulating hydropower startup and power generation taking into account frequency regulation requirements as described in any one of claims 1 to 7 is implemented.

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