Cost analysis method for energy storage assisted wind power primary frequency modulation

Abstract

The invention relates to an energy storage assisted wind power primary frequency modulation cost analysis method, which comprises the following steps of collecting related system parameters of a unit and energy storage, and establishing a frequency modulation standby supply model; collecting frequency parameters and renewable energy data of the system, and establishing a system frequency adjustment model and a new energy consumption model; through the frequency modulation standby supply model, the system frequency adjustment model and the new energy consumption model, establishing a power system scheduling model of energy storage auxiliary new energy providing primary frequency modulation; on the basis of system parameter input, solving the power system scheduling model to obtain dual multipliers of corresponding constraints; and by utilizing a marginal pricing principle and combining a dual multiplier of each constraint, calculating the cost of providing primary frequency modulation by the energy storage auxiliary new energy, thereby optimizing a frequency regulation scheme of the power system. Compared with the prior art, the method has the advantages of high stability, high accuracy, high reliability and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a cost analysis method and device for energy storage-assisted wind power primary frequency regulation. Background Art

[0002] In recent years, the penetration rate of renewable energy in the power system has continued to rise, and the increased volatility has triggered more auxiliary demands on the system. In order to meet the stability requirements of the system, the application of flexible resources represented by energy storage to provide frequency regulation is increasing. Establishing a reasonable pricing compensation mechanism can actively encourage energy storage to participate in the frequency regulation auxiliary market, thereby improving the allocation efficiency of auxiliary resources.

[0003] Researchers have accumulated fruitful research results in the field of calculating the costs and benefits of frequency regulation. For example, the document "Analysis of the benefits of energy storage participating in the frequency regulation market taking into account battery life" (Zhang Feng, Fang Le, Lu Chengyu, Deng Hui, Zhou Ziqing, Ma Junchao. Zhejiang Electric Power, 2021, 40(12): 61-68.) constructs a model of energy storage participating in the frequency regulation market based on the existing market framework. The model analyzes the impact of factors such as charge and discharge rate and charge and discharge depth on the life decay of energy storage batteries, and evaluates the actual impact of energy storage cycle life on frequency regulation benefits through a rain flow counting method. The document "Economic Research on Hybrid Energy Storage Participating in Secondary Frequency Regulation Based on Life Model" (Meng Jie, Ding Quan, Chen Xiaoyu, Qian Guoming, Huang Chao. Modern Electric Power, 2021, 38(02): 205-212.) proposed a hybrid energy storage frequency regulation control strategy taking into account battery life, established a hybrid energy storage life model containing lithium iron phosphate batteries and lead-carbon batteries, optimized power distribution through a first-order low-pass filter, measured frequency regulation compensation through the frequency regulation depth of energy storage, and constructed a hybrid energy storage frequency regulation model with the goal of maximizing economic benefits. The document "Application and Calculation Method of Energy Storage Participating in Auxiliary Market" (Chen Qian, Liu Wenfeng. Modern Information Technology, 2021, 5(18): 152-154.) proposed the assessment calculation of energy storage participating in the auxiliary market, clarified the charging and discharging behavior of energy storage under various abnormal conditions of the power grid and the specific standards that need to be met, and proposed corresponding compensation mechanisms for energy storage providing AGC according to the regulation capacity and regulation power. The document "Research on the Economic Efficiency of Frequency Regulation Based on the Life Cycle Cost of Energy Storage" (Wang Kai. Strait Science, 2021, (10): 28-31+35.) constructed a life cycle cost model for energy storage that takes into account multiple costs such as investment, operation and maintenance, and recovery value, and divided the benefits of energy storage participating in frequency regulation into two parts: capacity compensation and mileage compensation. It proposed a comprehensive frequency regulation index that takes into account the regulation rate, response time, and regulation accuracy, and formed an economic evaluation standard for energy storage participating in frequency regulation.

[0004] Based on various research results, there are already many patents on frequency regulation cost or benefit analysis. For example, the invention "Auxiliary pricing method for energy storage power station participating in power system frequency regulation" (Yan Gangui, Gao Kai, Ge Yanfeng, Zhao Weizhe, Li Junhui. CN201610820931.5[P]. 2016-12-14.) proposed a pricing method for energy storage power station participating in frequency regulation, which simulates the synchronous machine by setting the system differential coefficient, configures the capacity of energy storage to provide primary frequency regulation, and comprehensively calculates the benefits of energy storage participating in frequency regulation by combining the negative frequency regulation power and positive frequency regulation power of energy storage. The invention "A pricing method and device for providing backup assistance for new energy" (Fang Biwu, Fan Zhantao, Zhang Yong, Lou Nan, Chen Yiping, Huang He, Li Jianshe, Yang Lin, Zhao Huashi, Xiao Yi, Yan Rong, Zhang Hongxuan. CN202310725680.2[P]. 2023-09-15.) proposes a pricing method for providing backup assistance for new energy. The cost of the new energy rotating standby unit is determined by combining the market electricity price and the required backup capacity. The expected value of the system backup capacity is calculated through the specific parameters of the generator set, and the average benefit of the new energy rotating standby is obtained. Based on the cost and average benefit of the new energy rotating standby unit, a standby compensation pricing model is constructed. The invention "A cost accounting method for lithium battery energy storage and frequency regulation considering the impact of life degradation" (Yan Gangui, Liu Dongyuan, Li Junhui, Mu Gang. CN201710349451.X[P]. 2017-09-29.) proposes a cost accounting method for lithium battery energy storage and frequency regulation. In view of the problem that the cost caused by the degradation of lithium battery performance under operating conditions is difficult to calculate, a lithium battery life degradation model is established, and multiple factors such as lithium battery static loss, dynamic loss, investment cost and control strategy are comprehensively considered to form a more accurate cost accounting method for energy storage participating in grid frequency regulation.

[0005] However, the existing methods have the following defects:

[0006] 1. The current system dispatch model fails to fully incorporate the specific description of the system frequency regulation demand and the frequency regulation provided by energy storage, which makes it difficult to accurately reflect the process of energy storage participating in frequency regulation, thereby affecting the stability and security of power system frequency regulation.

[0007] 2. The cost calculation process focuses on the cost information of energy storage hardware, but lacks effective means to evaluate energy storage frequency regulation in the power system. Summary of the invention

[0008] The purpose of the present invention is to solve the technical problem of poor frequency regulation stability of the existing power system and to provide a cost analysis method and device for energy storage-assisted wind power primary frequency regulation.

[0009] The purpose of the present invention can be achieved by the following technical solutions:

[0010] A cost analysis method for energy storage-assisted wind power primary frequency regulation includes the following steps:

[0011] S1: Collect relevant system parameters of the units and energy storage, and establish a frequency regulation and standby supply model;

[0012] S2: Collect system frequency parameters and renewable energy data, and establish system frequency regulation model and new energy consumption model;

[0013] S3: Through the frequency regulation reserve supply model, system frequency regulation model and new energy consumption model, a power system dispatching model is established in which energy storage assists new energy to provide primary frequency regulation;

[0014] S4: Solve the power system dispatch model in which energy storage assists new energy to provide primary frequency regulation, and obtain the dual multipliers of each auxiliary corresponding constraint;

[0015] S5: The cost of providing primary frequency regulation by the energy storage device is calculated through the dual multipliers of each auxiliary corresponding constraint, thereby optimizing the frequency regulation scheme of the power system.

[0016] Further, step S1 includes:

[0017] S101: Collect relevant system parameters of the unit and energy storage, including thermal power unit parameters and energy storage equipment parameters; thermal power unit parameters include maximum power output, minimum power output, output cost, maximum frequency regulation capacity and unit frequency regulation time constant; energy storage equipment parameters include energy storage equipment capacity, maximum discharge power, maximum charging power, charging efficiency, discharge efficiency, energy storage frequency regulation time constant;

[0018] S102: Establish a frequency regulation reserve supply model, including the unit's frequency reserve model, the unit's inertia model and the energy storage's fast frequency reserve model. The unit's frequency reserve model includes the unit's frequency reserve power constraint and the unit's frequency reserve power output upper limit constraint; the unit's inertia model includes the unit's inertia constraint; the energy storage's frequency reserve model includes the energy storage frequency regulation reserve upper and lower limit constraints, the energy storage frequency regulation energy reserve constraint and the energy storage frequency regulation energy recovery constraint.

[0019] Furthermore, the unit frequency reserve model includes:

[0020] Unit frequency reserve power constraints:

[0021] Unit frequency standby power output upper limit constraint:

[0022] in, It is the frequency regulation reserve capacity of a single thermal power unit. It is the maximum frequency regulation capacity that a single thermal power unit can provide. For the output of a single thermal power unit, It is the maximum output of a single thermal power unit;

[0023] The unit inertia model includes:

[0024] Unit inertia constraint:

[0025] in, is the inertia of the unit, is the fixed inertia coefficient of unit u during operation;

[0026] Energy storage frequency reserve constraints include:

[0027] Energy storage frequency regulation reserve upper and lower limit constraints:

[0028] Energy reserve constraints for energy storage and frequency regulation:

[0029] in, Rapid frequency modulation power capacity for energy storage; and They are the charging power, discharging power and maximum output of a single energy storage unit respectively; is the energy storage level, t reg,dur is the duration of a frequency modulation, η d is the discharge efficiency of the energy storage device, The minimum energy level for energy storage.

[0030] Further, step S2 includes:

[0031] S201: Obtaining frequency parameters and renewable energy data of the system; the system frequency parameters include the system rated frequency, damping coefficient, maximum quasi-steady-state frequency deviation and maximum frequency deviation; the renewable energy data include the new energy output curve and unit output cost;

[0032] S202: Establish a frequency regulation model and a new energy consumption model for the system, including a storage-assisted new energy consumption model, a system frequency regulation standby metering model and a system frequency safety model. The storage-assisted new energy consumption model includes a new energy consumption output balance constraint; the system frequency regulation standby metering model includes the unit's total primary frequency regulation standby constraint, the energy storage's total primary frequency regulation standby constraint and the unit's total inertia constraint; the system frequency safety model includes the maximum quasi-steady-state frequency deviation constraint and the frequency minimum point constraint.

[0033] Furthermore, the energy storage-assisted new energy consumption model includes:

[0034] Constraints on the balance of new energy consumption output:

[0035] Among them, Ω k and Ω sThey are new energy collection and energy storage collection. and They are respectively the predicted wind power output, the actual amount of wind power on the grid, the actual amount of wind power abandoned, and the amount of charge received by the energy storage from wind power;

[0036] The frequency regulation reserve metering model includes:

[0037] Total primary frequency regulation reserve constraints of the unit:

[0038] Total primary frequency regulation reserve constraints of energy storage:

[0039] Total inertia constraint of the unit:

[0040] in, It is the total frequency regulation capacity of thermal power units; Total frequency regulation capacity for energy storage; is the total inertia level of the thermal power unit;

[0041] The system frequency security model includes:

[0042] Maximum quasi-steady-state frequency deviation constraint:

[0043] Frequency minimum point constraint:

[0044] in, Indicates the load power shortage under system fluctuations; Indicates the maximum quasi-steady-state frequency deviation of the system, f D represents the system damping coefficient, represents the total system load at time t; Δf max represents the maximum frequency deviation of the system, f0 represents the standard frequency of the system, T e Represents the energy storage frequency modulation time constant, T g Indicates the unit frequency regulation time constant.

[0045] Furthermore, in step S3, the power system dispatching model in which energy storage assists new energy to provide primary frequency regulation is adopted. The overall model is a convex optimization planning, and the objective function of the power system dispatching model is to minimize the sum of electric energy and frequency regulation declaration cost.

[0046] Furthermore, the calculation expression of the objective function of the power system dispatch model is:

[0047] min.(VC+WSC)

[0048]

[0049] Among them, VC represents the unit cost, and WSC represents the cost of new energy and energy storage; They are the output unit price of thermal power units and the declared unit price of primary frequency regulation; c w 、c s , They are the unit price of new energy output, the unit price of energy storage discharge / power purchase, and the unit price of energy storage rapid frequency regulation declaration; For the output of a single thermal power unit, It is wind power output. is the energy storage discharge power, Purchase power for energy storage, It is the frequency regulation reserve capacity of a single thermal power unit. Rapid frequency modulation power capacity for energy storage.

[0050] Furthermore, in step S4, the power system dispatching model in which energy storage assists renewable energy to provide primary frequency regulation is a convex optimization model. By solving the model, the dual multiplier corresponding to the primary frequency regulation constraint is obtained, and the Lagrangian function containing the energy storage rapid frequency regulation variable is obtained. The calculation expression of the dual multiplier of the constraint is:

[0051]

[0052] Among them, ω ss is the dual multiplier of the maximum quasi-steady-state frequency deviation constraint of the system; μ, λ1, λ2 are the dual multipliers of the original quadratic terms corresponding to the constraint of the lowest frequency point of the system respectively; is the dual multiplier of the total primary frequency regulation constraint of energy storage, … are other constraints that do not contain fast frequency regulation variables, Indicates the load power shortage under system fluctuations; Indicates the maximum quasi-steady-state frequency deviation of the system, f D represents the system damping coefficient, represents the total system load at time t; Δf max represents the maximum frequency deviation of the system, f0 represents the standard frequency of the system, T e Represents the energy storage frequency modulation time constant, T g Indicates the unit frequency regulation time constant, is the total inertia constraint of the unit, Rapid frequency modulation power capacity for energy storage.

[0053] Furthermore, the calculation process of step S5 is:

[0054] S51: Lagrangian functions with respect to fast frequency modulation variables Find the partial derivative, according to the stationarity requirement:

[0055]

[0056] S52: Calculate fast frequency modulation variable marginal cost;

[0057]

[0058] S53: Calculate the rapid frequency modulation auxiliary cost according to the Lagrangian function expression in step S4, and the calculation expression is:

[0059]

[0060] in, The cost of providing fast frequency regulation for energy storage, C represents the constraint term with dual multipliers in the Lagrangian function, T e is the energy storage frequency modulation time constant, Δf max is the maximum frequency deviation, μ, λ1, and λ2 are the dual multipliers of the original quadratic terms corresponding to the lowest frequency constraint of the system. For, ss is the dual multiplier of the maximum quasi-steady-state frequency deviation constraint of the system.

[0061] A second aspect of the present invention is a storage medium, including a program stored therein, which executes any one of the above cost analysis methods for energy storage-assisted wind power primary frequency regulation when the program is running.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] 1) The present invention incorporates frequency regulation constraints by establishing a frequency regulation reserve supply model, a system frequency regulation model and a new energy consumption model, and more accurately models the process of energy storage equipment participating in frequency regulation. The dual multipliers corresponding to the model calculation constraints are used to accurately calculate the cost of energy storage equipment participating in frequency regulation through the dual multipliers, thereby effectively incorporating the flexibility of energy storage equipment into the scope of system frequency regulation and scheduling, which is used to optimize the allocation of auxiliary resources. Compared with traditional models, the stability and safety of the power system are significantly improved.

[0064] 2) The present invention obtains the precise parameters required to calculate the primary frequency regulation cost provided by energy storage by running a power system dispatching model that embeds energy storage to participate in frequency regulation, and by running and solving a convex optimization plan, thereby improving the accuracy and reliability of energy storage cost prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is the overall flow chart of the present invention.

[0066] Figure 2 It is the algorithm flow chart of the present invention. DETAILED DESCRIPTION

[0067] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0068] Example 1

[0069] refer to Figure 1 As shown, this embodiment provides a cost analysis method for energy storage-assisted wind power primary frequency regulation, including the following steps:

[0070] S1: Collect relevant system parameters of the units and energy storage, and establish frequency regulation and backup supply;

[0071] S101: Collect relevant system parameters of the unit and energy storage, including thermal power unit parameters and energy storage equipment parameters; thermal power unit parameters include maximum power output, minimum power output, output cost, maximum frequency regulation capacity and unit frequency regulation time constant; energy storage equipment parameters include energy storage equipment capacity, maximum discharge power, maximum charging power, charging efficiency, discharge efficiency, energy storage frequency regulation time constant;

[0072] S102: Establish a frequency regulation reserve supply model, including the unit's frequency reserve model, the unit's inertia model and the energy storage's fast frequency reserve model. The unit's frequency reserve model includes the unit's frequency reserve power constraint and the unit's frequency reserve power output upper limit constraint; the unit's inertia model includes the unit's inertia constraint; the energy storage's frequency reserve model includes the energy storage frequency regulation reserve upper and lower limit constraints, the energy storage frequency regulation energy reserve constraint and the energy storage frequency regulation energy recovery constraint.

[0073] Furthermore, the unit frequency reserve model includes:

[0074] Unit frequency reserve power constraints:

[0075] Unit frequency standby power output upper limit constraint:

[0076] in, It is the frequency regulation reserve capacity of a single thermal power unit. is the maximum frequency regulation capacity that a single thermal power unit can provide, P u,t For the output of a single thermal power unit, It is the maximum output of a single thermal power unit;

[0077] The unit inertia model includes:

[0078] Unit inertia constraint:

[0079] in, is the inertia of the unit, is the fixed inertia coefficient of unit u during operation;

[0080] Energy storage frequency reserve constraints include:

[0081] Energy storage frequency regulation reserve upper and lower limit constraints:

[0082] Energy reserve constraints for energy storage and frequency regulation:

[0083] in, Rapid frequency modulation power capacity for energy storage; and They are the charging power, discharging power and maximum output of a single energy storage unit respectively; is the energy storage level, t reg,dur is the duration of a frequency modulation, η d is the discharge efficiency of the energy storage device, The minimum energy level for energy storage.

[0084] S2: Collect system frequency parameters and renewable energy data, and establish system frequency regulation model and new energy consumption model;

[0085] S201: Obtaining frequency parameters and renewable energy data of the system; the system frequency parameters include the system rated frequency, damping coefficient, maximum quasi-steady-state frequency deviation and maximum frequency deviation; the renewable energy data include the new energy output curve and unit output cost;

[0086] S202: Establish a frequency regulation model and a new energy consumption model for the system, including a storage-assisted new energy consumption model, a system frequency regulation standby metering model and a system frequency safety model. The storage-assisted new energy consumption model includes a new energy consumption output balance constraint; the system frequency regulation standby metering model includes the unit's total primary frequency regulation standby constraint, the energy storage's total primary frequency regulation standby constraint and the unit's total inertia constraint; the system frequency safety model includes the maximum quasi-steady-state frequency deviation constraint and the frequency minimum point constraint.

[0087] Energy storage-assisted new energy consumption models include:

[0088] Constraints on the balance of new energy consumption output:

[0089] Among them, Ω k and Ω s They are new energy collection and energy storage collection. and They are respectively the predicted wind power output, the actual amount of wind power on the grid, the actual amount of wind power abandoned, and the amount of charge received by the energy storage from wind power;

[0090] The frequency regulation reserve metering model includes:

[0091] Total primary frequency regulation reserve constraints of the unit:

[0092] Total primary frequency regulation reserve constraints of energy storage:

[0093] Total inertia constraint of the unit:

[0094] in, It is the total frequency regulation capacity of thermal power units; Total frequency regulation capacity for energy storage; is the total inertia level of the thermal power unit;

[0095] The system frequency security model includes:

[0096] Maximum quasi-steady-state frequency deviation constraint:

[0097] Frequency minimum point constraint:

[0098] in, Indicates the load power shortage under system fluctuations; Indicates the maximum quasi-steady-state frequency deviation of the system, f D represents the system damping coefficient, represents the total system load at time t; Δf max represents the maximum frequency deviation of the system, f0 represents the standard frequency of the system, T e Represents the energy storage frequency modulation time constant, T g Indicates the unit frequency regulation time constant.

[0099] In this embodiment, the frequency minimum point constraint contains a quadratic term but is actually convex because it is essentially a second-order cone constraint and can be converted into a second-order cone form. The calculation expression is:

[0100]

[0101] S3: Through the frequency regulation reserve supply model, system frequency regulation model and new energy consumption model, a power system dispatching model is established in which energy storage assists new energy to provide primary frequency regulation;

[0102] Specifically, in this embodiment, the objective function of the power system dispatching model in which energy storage assists new energy to provide primary frequency regulation is to minimize the sum of electric energy and frequency regulation declaration cost:

[0103] min.(VC+WSC)

[0104]

[0105] Among them, VC represents the unit cost, and WSC represents the cost of new energy and energy storage; They are the output unit price of thermal power units and the declared unit price of primary frequency regulation; c w 、c s , They are the unit price of new energy output, the unit price of energy storage discharge / power purchase, and the unit price of energy storage rapid frequency regulation declaration; For the output of a single thermal power unit, It is wind power output. is the energy storage discharge power, Purchase power for energy storage, It is the frequency regulation reserve capacity of a single thermal power unit. Rapid frequency modulation power capacity for energy storage.

[0106] In this embodiment, the constraints of the power system dispatching model in which energy storage assists new energy to provide primary frequency regulation include the above-mentioned models S100 and S200, and it is also necessary to supplement the energy storage operation, unit operation and grid operation structure. There is no specific restriction on the supplementary content, and the model can be formed as long as it conforms to logic.

[0107] S4: Solve the power system dispatch model in which energy storage assists new energy to provide primary frequency regulation, and obtain the dual multipliers of each auxiliary corresponding constraint;

[0108] Specifically, in this implementation example, the marginal pricing theory is applied to evaluate the cost of energy storage assisting renewable energy in providing primary frequency regulation. A core requirement of this method is that the optimization model must maintain convexity, which is to ensure that the marginal price of resources can be determined by solving the dual variables of the constraint conditions.

[0109] In this embodiment, the power system dispatch model for providing primary frequency modulation with energy storage assisting new energy is a convex optimization model. The dual multiplier corresponding to the primary frequency modulation constraint can be obtained by solving the model, and the Lagrangian function containing the energy storage rapid frequency modulation variable is obtained. The dual multiplier of the constraint is expressed as follows:

[0110]

[0111] Among them, ω ss is the dual multiplier of the maximum quasi-steady-state frequency deviation constraint of the system; μ, λ1, λ2 are the dual multipliers of the original quadratic terms corresponding to the constraint of the lowest frequency point of the system respectively; is the dual multiplier of the total primary frequency regulation constraint of energy storage, … are other constraints that do not contain fast frequency regulation variables, Indicates the load power shortage under system fluctuations; Indicates the maximum quasi-steady-state frequency deviation of the system, f D represents the system damping coefficient, represents the total system load at time t; Δf max represents the maximum frequency deviation of the system, f0 represents the standard frequency of the system, T e Represents the energy storage frequency modulation time constant, T g Indicates the unit frequency regulation time constant, is the total inertia constraint of the unit, Rapid frequency modulation power capacity for energy storage.

[0112] S5: The cost of providing primary frequency regulation by energy storage is calculated through the dual multipliers of each auxiliary corresponding constraint, thereby optimizing the auxiliary scheduling plan of energy storage equipment.

[0113] In this embodiment, the marginal pricing method is used to calculate the cost of energy storage assisting new energy in providing primary frequency regulation, and the steps include:

[0114] S51: Lagrangian functions with respect to fast frequency modulation variables Find the partial derivative. The stability requirement of the KKT condition states that the gradient of the Lagrangian function at the optimal solution is 0, that is:

[0115]

[0116] S52: Calculate fast frequency modulation variable The marginal cost of the product is:

[0117]

[0118] S53: Calculate the fast frequency modulation auxiliary cost using the Lagrangian function constructed in step S4, and the calculation expression is:

[0119]

[0120] in, The cost of providing fast frequency regulation for energy storage, C represents the constraint term with dual multipliers in the Lagrangian function, T e is the energy storage frequency modulation time constant, Δf max is the maximum frequency deviation, μ, λ1, and λ2 are the dual multipliers of the original quadratic terms corresponding to the lowest frequency constraint of the system. For, ss is the dual multiplier of the maximum quasi-steady-state frequency deviation constraint of the system.

[0121] Example 2

[0122] On the basis of Example 1, Figure 2As shown, the present invention can be implemented through program code, by importing thermal power unit system parameters, energy storage system parameters, system frequency parameters and renewable energy output parameters, establishing thermal power unit frequency standby, inertia model and energy storage rapid frequency regulation model, further establishing new energy consumption output balance model, system frequency regulation metering model and system frequency safety model, by establishing a cost minimization objective function, supplementing the operation model, forming a complete power system dispatching model, solving the dual multipliers of various related constraints, and obtaining the cost of primary frequency regulation provided by energy storage through the dual multipliers, thereby optimizing the frequency regulation scheme of the power system.

[0123] The program code for implementing the method of the present invention can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partially on the machine, partially on the machine as a stand-alone software package and partially on a remote machine, or entirely on a remote machine or server.

[0124] The program code of the present invention can be stored by a machine-readable medium as a carrier, and the machine-readable medium can be a tangible medium that can contain or store a program for use by an instruction execution system, a device or an equipment or used in combination with an instruction execution system, a device or an equipment. The machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the above. A more specific example of a machine-readable storage medium can include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0125] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A cost analysis method for energy storage-assisted wind power primary frequency regulation, characterized in that: The following steps are involved: S1: Collect relevant system parameters of the units and energy storage, and establish a frequency regulation and standby supply model; S2: Collect system frequency parameters and renewable energy data, and establish system frequency regulation model and new energy consumption model; S3: Through the frequency regulation reserve supply model, system frequency regulation model and new energy consumption model, a power system dispatching model is established in which energy storage assists new energy to provide primary frequency regulation; S4: Solve the power system dispatch model in which energy storage assists new energy to provide primary frequency regulation, and obtain the dual multipliers of each auxiliary corresponding constraint; S5: The cost of providing primary frequency regulation by the energy storage device is calculated through the dual multipliers of each auxiliary corresponding constraint, thereby optimizing the frequency regulation scheme of the power system.

2. According to claim 1, a cost analysis method for energy storage-assisted wind power primary frequency regulation is characterized in that: Step S1 includes: S101: Collect relevant system parameters of the unit and energy storage, including thermal power unit parameters and energy storage equipment parameters; the thermal power unit parameters include maximum power output, minimum power output, output cost, maximum frequency regulation capacity and unit frequency regulation time constant; the energy storage equipment parameters include energy storage equipment capacity, maximum discharge power, maximum charging power, charging efficiency, discharge efficiency, energy storage frequency regulation time constant; S102: Establish a frequency regulation reserve supply model, including a frequency reserve model of the unit, an inertia model of the unit and a fast frequency reserve model of energy storage, wherein the frequency reserve model of the unit includes a frequency reserve power constraint of the unit and an upper limit constraint of the frequency reserve power output of the unit; the inertia model of the unit includes a unit inertia constraint; the frequency reserve model of the energy storage includes upper and lower limit constraints of energy storage frequency regulation reserve, energy storage frequency regulation energy reserve constraints and energy storage frequency regulation energy recovery constraints.

3. According to claim 2, a cost analysis method for energy storage-assisted wind power primary frequency regulation is characterized in that: The unit frequency standby model includes: Unit frequency reserve power constraints: Unit frequency standby power output upper limit constraint: in, It is the frequency regulation reserve capacity of a single thermal power unit. is the maximum frequency regulation capacity that a single thermal power unit can provide, P u,t For the output of a single thermal power unit, It is the maximum output of a single thermal power unit; The unit inertia model includes: Unit inertia constraint: in, is the inertia of the unit, is the fixed inertia coefficient of unit u during operation; The energy storage frequency reserve constraint includes: Energy storage frequency regulation reserve upper and lower limit constraints: Energy reserve constraints for energy storage and frequency regulation: in, Rapid frequency modulation power capacity for energy storage; and They are the charging power, discharging power and maximum output of a single energy storage unit respectively; is the energy storage level, t reg,dir is the duration of a frequency modulation, η d is the discharge efficiency of the energy storage device, The minimum energy level for energy storage.

4. According to claim 1, a cost analysis method for energy storage-assisted wind power primary frequency regulation is characterized in that: Step S2 includes: S201: Obtaining frequency parameters and renewable energy data of the system; the system frequency parameters include the system rated frequency, damping coefficient, maximum quasi-steady-state frequency deviation and maximum frequency deviation; the renewable energy data include new energy output curve and unit output cost; S202: Establish a frequency regulation model and a new energy consumption model for the system, including an energy storage-assisted new energy consumption model, a system frequency regulation standby metering model and a system frequency safety model. The energy storage-assisted new energy consumption model includes a new energy consumption output balance constraint; the system frequency regulation standby metering model includes a total primary frequency regulation standby constraint of the unit, a total primary frequency regulation standby constraint of energy storage and a total inertia constraint of the unit; the system frequency safety model includes a maximum quasi-steady-state frequency deviation constraint and a frequency minimum point constraint.

5. A cost analysis method for energy storage-assisted wind power primary frequency regulation according to claim 4, characterized in that: The energy storage-assisted new energy consumption model includes: Constraints on the balance of new energy consumption output: Among them, Ω k and Ω s They are new energy collection and energy storage collection. and They are respectively the predicted wind power output, the actual amount of wind power on the grid, the actual amount of wind power abandoned, and the amount of charge received by the energy storage from wind power; The frequency regulation standby metering model includes: Total primary frequency regulation reserve constraints of the unit: Total primary frequency regulation reserve constraints of energy storage: Total inertia constraint of the unit: in, It is the total frequency regulation capacity of thermal power units; Total frequency regulation capacity for energy storage; is the total inertia level of the thermal power unit; The system frequency security model includes: Maximum quasi-steady-state frequency deviation constraint: Frequency minimum point constraint: in, Indicates the load power shortage under system fluctuations; Indicates the maximum quasi-steady-state frequency deviation of the system, f D represents the system damping coefficient, represents the total system load at time t; Δf max represents the maximum frequency deviation of the system, f0 represents the standard frequency of the system, T e Represents the energy storage frequency modulation time constant, T g Indicates the unit frequency regulation time constant.

6. The cost analysis method for energy storage-assisted wind power primary frequency regulation according to claim 1, characterized in that: In step S3, the energy storage assists new energy to provide a power system dispatching model for primary frequency regulation. The model as a whole is a convex optimization planning, and the objective function of the power system dispatching model is to minimize the sum of electric energy and frequency regulation declaration cost.

7. A cost analysis method for energy storage-assisted wind power primary frequency regulation according to claim 6, characterized in that: The calculation expression of the objective function of the power system dispatch model is: Among them, VC represents the unit cost, and WSC represents the cost of new energy and energy storage; They are the output unit price of thermal power units and the declared unit price of primary frequency regulation; c w 、c s , They are the unit price of new energy output, the unit price of energy storage discharge / power purchase, and the unit price of energy storage rapid frequency regulation declaration; For the output of a single thermal power unit, It is wind power output. is the energy storage discharge power, Purchase power for energy storage, It is the frequency regulation reserve capacity of a single thermal power unit. Rapid frequency modulation power capacity for energy storage.

8. The cost analysis method for energy storage-assisted wind power primary frequency regulation according to claim 1, characterized in that: In step S4, the power system dispatching model for energy storage to assist new energy in providing primary frequency regulation is a convex optimization model. By solving the model, the dual multiplier corresponding to the primary frequency regulation constraint is obtained, and the Lagrangian function containing the energy storage rapid frequency regulation variable is obtained. The calculation expression of the dual multiplier of the constraint is: Among them, ω ss is the dual multiplier of the maximum quasi-steady-state frequency deviation constraint of the system; μ, λ1, λ2 are the dual multipliers of the original quadratic terms corresponding to the constraint of the lowest frequency point of the system respectively; is the dual multiplier of the total primary frequency regulation constraint of energy storage, … are other constraints that do not contain fast frequency regulation variables, Indicates the load power shortage under system fluctuations; Indicates the maximum quasi-steady-state frequency deviation of the system, f D represents the system damping coefficient, represents the total system load at time t; Δf max represents the maximum frequency deviation of the system, f0 represents the standard frequency of the system, T e Represents the energy storage frequency modulation time constant, T g Indicates the unit frequency regulation time constant, is the total inertia constraint of the unit, Rapid frequency modulation power capacity for energy storage.

9. A cost analysis method for energy storage-assisted wind power primary frequency regulation according to claim 8, characterized in that: The calculation process of step S5 is: S51: Lagrangian functions with respect to fast frequency modulation variables Find the partial derivative, according to the stationarity requirement: S52: Calculate fast frequency modulation variable marginal cost; S53: Calculate the rapid frequency modulation auxiliary cost according to the Lagrangian function expression in step S4, and the calculation expression is: in, The cost of providing fast frequency regulation for energy storage, C represents the constraint term with dual multipliers in the Lagrangian function, T e is the energy storage frequency modulation time constant, Δf max is the maximum frequency deviation, μ, λ1, and λ2 are the dual multipliers of the original quadratic terms corresponding to the lowest frequency constraint of the system. For, ss is the dual multiplier of the maximum quasi-steady-state frequency deviation constraint of the system.

10. A storage medium, characterized in that: It includes a program stored therein, and when the program is run, it executes a cost analysis method for energy storage-assisted wind power primary frequency regulation as described in any one of claims 1-9.

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