Coordinated frequency regulation method, device and system for thermal power generation unit and energy storage system

Abstract

The present application relates to a method, device and system for coordinated frequency regulation of a thermal power unit and an energy storage system, wherein the method comprises: obtaining an AGC instruction and a mapping relationship between the SOC state of the battery energy storage and a decision variable, pre-allocating the output of the thermal power unit and the output of the energy storage system through the AGC instruction, the mapping relationship and the secondary frequency regulation model of the thermal power unit; allocating the output of the energy storage system into the battery energy storage output and the flywheel energy storage output according to a preset rule, and constraining the output power of the battery energy storage output and the flywheel energy storage output according to the SOC state of the battery energy storage and the flywheel energy storage during the allocation process; determining the investment cost and the frequency regulation benefit of the energy storage system based on the output of the thermal power unit, the battery energy storage output and the flywheel energy storage output, thereby constructing an economic model, solving the target decision variable with the goal of maximizing the benefit of the economic model; determining the frequency regulation instruction of the thermal power unit according to the target decision variable and the AGC instruction, so that the thermal power unit can perform frequency regulation according to the frequency regulation instruction of the thermal power unit.

Description

Technical Field

[0001] The present application relates to the research field of thermal-storage combined secondary frequency regulation, and in particular to a method, device and system for coordinated frequency regulation of a thermal power unit and an energy storage system. Background Art

[0002] The high proportion of intermittent and volatile renewable energy access leads to frequent fluctuations in power, and the system power balance faces severe challenges. At present, the problem of power system frequency regulation is becoming more and more prominent, and the frequency regulation performance of generator sets needs to be improved urgently.

[0003] At present, thermal power units are used as the main frequency regulation power source of the power system, but the response speed of thermal power units is slow. It usually takes about 2 minutes for a 330MW unit to respond to a 15MW automatic generation control (AGC) command. Frequent frequency regulation can easily cause serious wear and tear of the unit. The loss cost caused by frequency regulation of the unit can reach tens of millions of yuan each year. The regulation performance is low. The comprehensive regulation performance Kp of the unit is usually between 1-2, and even a few units have Kp <1. Therefore, it is necessary to improve the frequency regulation performance of thermal power units. The existing technology uses battery energy storage system (BESS) to assist thermal power units in frequency regulation, which is low in cost, but irregular deep charging and discharging will seriously affect the battery life and cause the battery chemical performance to deteriorate.

[0004] Therefore, the regulation performance of the existing technology is insufficient, and a more flexible and efficient regulation method is needed. Summary of the invention

[0005] The embodiments of the present application provide a method, device and system for coordinated frequency regulation of a thermal power unit and an energy storage system, so as to at least solve the problem of insufficient regulation performance in the related art.

[0006] In a first aspect, an embodiment of the present application provides a method for coordinated frequency regulation of a thermal power unit and an energy storage system, the method comprising:

[0007] Obtaining an AGC instruction and a mapping relationship between the SOC state of the battery energy storage and the decision variable, and pre-allocating the output of the thermal power unit and the output of the energy storage system through the AGC instruction, the mapping relationship and the secondary frequency regulation model of the thermal power unit;

[0008] Allocate the energy storage system output into battery energy storage output and flywheel energy storage output according to preset rules, and constrain the output power of the battery energy storage output and flywheel energy storage output according to the SOC states of the battery energy storage and the flywheel energy storage during the allocation process;

[0009] Determine the investment cost and frequency regulation benefit of the energy storage system based on the output of thermal power units, battery energy storage output and flywheel energy storage output, build an economic model based on the investment cost and frequency regulation benefit of the energy storage system, and solve the target decision variables with the goal of maximizing the benefit of the economic model;

[0010] A frequency regulation instruction of the thermal power unit is determined according to the target decision variable and the AGC instruction, so that the thermal power unit can regulate the frequency according to the frequency regulation instruction of the thermal power unit.

[0011] In one embodiment, the output of the thermal power unit and the output of the energy storage system are allocated by the AGC instruction and the mapping relationship, including:

[0012] In response to the power amplitude of the AGC instruction being within a preset range, determining a response ratio of the thermal power unit according to the mapping relationship;

[0013] Generate a frequency regulation instruction for the thermal power unit according to the ratio, and obtain the output of the thermal power unit according to a secondary frequency regulation model of the thermal power unit based on the frequency regulation instruction for the thermal power unit;

[0014] The AGC instruction is converted into a frequency modulation demand signal, and a frequency modulation demand signal of the energy storage system is obtained according to the frequency modulation demand signal and the output of the thermal power unit.

[0015] In one embodiment, the energy storage system output is allocated into battery energy storage output and flywheel energy storage output according to a preset rule, and during the allocation process, the output power of the battery energy storage output and the flywheel energy storage output is constrained according to the SOC state of the battery energy storage and the flywheel energy storage, including:

[0016] According to the preset rules, the battery energy storage output at the first target moment is determined according to the SOC-related parameters of the battery energy storage, the frequency regulation demand signal of the energy storage system and the rated power of the battery energy storage; the flywheel energy storage output at the first target moment is determined according to the SOC-related parameters of the flywheel energy storage, the frequency regulation demand signal of the energy storage system and the rated power of the flywheel energy storage;

[0017] Determine the SOC of the battery energy storage at the second target time according to the rated capacity, charging efficiency and discharging efficiency of the battery energy storage, the SOC at the first target time and the output of the battery energy storage, and determine the SOC of the flywheel energy storage at the second target time according to the rated capacity, charging efficiency and discharging efficiency of the flywheel energy storage, the SOC at the first target time and the output of the flywheel energy storage;

[0018] The output power during the battery energy storage output process is constrained according to the SOC, maximum charge and discharge output, highest battery energy storage and lowest battery energy storage of the battery energy storage at the second target moment; the output power during the flywheel energy storage output process is constrained according to the SOC, maximum charge and discharge output, highest flywheel energy storage and lowest flywheel energy storage of the flywheel energy storage at the second target moment.

[0019] In one embodiment, the secondary frequency regulation characteristic model of the thermal power unit is configured to segment the response process of the thermal power unit according to the regulation intensity, and each segment corresponds to different adaptive parameters to reflect different response characteristics.

[0020] In one embodiment, the secondary frequency regulation characteristic model of the thermal power unit is configured to be obtained in the following manner:

[0021] Determine the regulation intensity according to the AGC instruction, divide the operating conditions of the thermal power unit according to the regulation intensity, and obtain the secondary frequency regulation response information of the thermal power unit under each operating condition;

[0022] The target adjustment process is selected according to a preset time threshold and the response information, and the response characteristic information is obtained according to the target adjustment process and the output of the corresponding thermal power unit;

[0023] A secondary frequency regulation characteristic model of a thermal power unit is constructed according to the AGC instruction and the response characteristic information, and the secondary frequency regulation characteristic model of the thermal power unit is solved by an optimization algorithm to obtain adaptive parameters of each section.

[0024] In one embodiment, the investment cost includes annual average configuration cost, annual average replacement cost, operation and maintenance cost, failure loss cost, power loss cost, decommissioning disposal cost and recovery benefit;

[0025] Determine the average annual configuration cost based on the unit power investment cost, unit capacity investment cost, rated power, rated capacity, one-time cash factor, base discount rate and project operation cycle of battery energy storage and flywheel energy storage;

[0026] Determine the average annual replacement cost based on the unit power investment cost, unit capacity investment cost, rated power, rated capacity and number of replacements during the project operation cycle of the battery energy storage;

[0027] Determine the operation and maintenance costs based on the rated power, rated capacity, maintenance cost per unit power and maintenance cost per unit capacity of the battery energy storage and flywheel energy storage;

[0028] Determine the failure loss cost based on the average annual number of failures, average failure handling cost, average annual energy storage charging and discharging capacity, average annual power outage duration, and average annual ancillary service market electricity price;

[0029] Determine the power loss cost based on the battery energy storage output, flywheel energy storage output, unit price of lost power, charging efficiency and discharging efficiency of battery energy storage and flywheel energy storage;

[0030] The decommissioning disposal cost is determined based on the decommissioning disposal cost per unit power, the decommissioning disposal cost per unit capacity, the cash factor of the one-time payment, the number of replacements within the project operation cycle, the rated power of the battery energy storage, and the rated capacity of the battery energy storage;

[0031] The recycling benefit is determined based on the recycling revenue per megawatt of battery energy storage, the weight of lithium phosphate batteries per megawatt, metal prices, metal content per unit weight, rated power of battery energy storage, life cycle and discount rate.

[0032] In one embodiment, the energy storage system frequency regulation benefits include: direct benefits of regulation performance compensation, indirect benefits of equivalent unit wear reduction costs, indirect benefits of equivalent reduction of system power generation fuel costs, and indirect benefits of equivalent reduction of system power generation pollution costs;

[0033] Determine the direct benefits of regulation performance compensation based on the total regulation depth of thermal power units per day, comprehensive regulation performance indicators, and compensation price of AGC frequency regulation;

[0034] Determine the indirect benefits of equivalent unit wear reduction costs based on the proportion of wear caused by thermal power units participating in secondary frequency regulation to total losses and the total loss costs of thermal power units;

[0035] Determine the indirect benefits of equivalently reducing the system power generation fuel cost based on the frequency regulation discharge power, the fuel quantity required per unit power generation, the fuel unit price and the cash factor of the one-time payment;

[0036] The indirect benefits of equivalently reducing the system's power generation and emission costs are determined based on the emission costs of nitrogen oxides, sulfur dioxide and carbon dioxide required for unit power generation, the cash coefficient of the one-time payment and the frequency regulation discharge electricity.

[0037] In a second aspect, an embodiment of the present application provides a device for coordinated frequency regulation of a thermal power generation unit and an energy storage system, wherein the device is used to implement the method for coordinated frequency regulation of a thermal power generation unit and an energy storage system as described in the first aspect.

[0038] The device comprises a thermal power unit module and an energy storage module, wherein the energy storage module comprises battery energy storage and flywheel energy storage;

[0039] The device also includes a controller, which is used to determine the frequency modulation instruction of the thermal power unit, the battery energy storage frequency modulation instruction and the flywheel energy storage frequency modulation instruction according to the AGC instruction and the state of the energy storage module, so that the thermal power unit module, the battery energy storage and the flywheel energy storage can perform frequency modulation according to the corresponding instructions respectively.

[0040] In a third aspect, an embodiment of the present application provides a coordinated frequency regulation system of a thermal power unit and an energy storage system, the system comprising:

[0041] The first allocation module is used to obtain the AGC instruction and the mapping relationship between the SOC state of the battery energy storage and the decision variable, and pre-allocate the output of the thermal power unit and the output of the energy storage system through the AGC instruction, the mapping relationship and the secondary frequency regulation model of the thermal power unit;

[0042] The second allocation module is used to allocate the output of the energy storage system into the battery energy storage output and the flywheel energy storage output according to the preset rules, and in the allocation process, constrain the output power of the battery energy storage output and the flywheel energy storage output according to the SOC state of the battery energy storage and the flywheel energy storage;

[0043] Economic module: used to determine the investment cost and frequency regulation benefits of the energy storage system based on the output of thermal power units, battery energy storage output and flywheel energy storage output, build an economic model based on the investment cost and frequency regulation benefits of the energy storage system, and solve the target decision variables with the goal of maximizing the benefits of the economic model;

[0044] Frequency modulation module: used to determine the frequency modulation instruction of the thermal power unit according to the target decision variable and the AGC instruction, so that the thermal power unit can perform frequency modulation according to the frequency modulation instruction of the thermal power unit.

[0045] In a fourth aspect, an embodiment of the present application provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for coordinated frequency regulation of a thermal power unit and an energy storage system as described in the first aspect above is implemented.

[0046] The embodiments of the present application provide a method, device and system for coordinated frequency regulation of a thermal power unit and an energy storage system, which have at least the following technical effects.

[0047] This application uses battery energy storage and flywheel energy storage to assist thermal power units in frequency regulation, which reduces the frequency regulation loss of thermal power units on the one hand and improves the frequency regulation effect on the other. At the same time, this application designs the output allocation strategy between thermal power units and hybrid energy storage, constructs an economic model of the thermal power units and hybrid energy storage collaborative system, and optimizes the target decision variables through the optimization algorithm. This ensures the economy and frequency regulation effect of dynamic frequency regulation.

[0048] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0050] Figure 1is a structural schematic diagram of a thermal power unit and an energy storage coordinated system according to an exemplary embodiment;

[0051] Figure 2 is a schematic diagram showing the influence of adjustment intensity on adjustment time according to an exemplary embodiment;

[0052] Figure 3 is a schematic diagram of a secondary frequency regulation response characteristic model of a thermal power unit according to an exemplary embodiment;

[0053] Figure 4 is a schematic diagram of a thermal power unit response process segmented according to an exemplary embodiment;

[0054] Figure 5 is a schematic diagram of a hybrid energy storage system model according to an exemplary embodiment;

[0055] Figure 6 It is a flow chart of a method for coordinated frequency regulation of a thermal power unit and an energy storage system provided in an embodiment of the present application;

[0056] Figure 7 is a schematic diagram of a model tracking process according to an exemplary embodiment;

[0057] Figure 8 is a schematic diagram showing a comparison of frequency modulation curves according to an exemplary embodiment;

[0058] Fig. 9 is a structural schematic diagram of a coordinated frequency regulation device of a thermal power unit and an energy storage system according to an exemplary embodiment;

[0059] Fig.10 is a structural schematic diagram of coordinated frequency regulation of a thermal power unit and an energy storage system according to an exemplary embodiment;

[0060] Fig.11 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0062] Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in this field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.

[0063] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0064] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantity limitation, and may indicate the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0065] In a first aspect, an embodiment of the present application provides a method for coordinated frequency regulation of a thermal power unit and an energy storage system.

[0066] Before step S101, a data-driven thermal power unit and energy storage coordination system is designed to address the frequency regulation performance issues of the current thermal power units. The AGC instruction automatically adjusts the output power of the generator to maintain a balance between the generator's power generation and the load power demand to cope with load fluctuations and other external disturbances, thereby maintaining the stable operation of the entire power system. Figure 1 is a schematic diagram of a thermal power unit and an energy storage coordinated system according to an exemplary embodiment. Figure 1 As shown, the thermal power unit and energy storage coordinated system includes a thermal power unit and a hybrid energy storage system, wherein the hybrid energy storage system includes battery energy storage and flywheel energy storage. This application aims to design a frequency modulation dynamic proportional control method for the frequency modulation characteristics of the thermal power unit, battery energy storage and flywheel energy storage in the thermal power unit and energy storage coordinated system.

[0067] The operation data of thermal power units include the dynamic response information of the units. The mechanism model of the thermal power units is combined with the operation data. Based on the operation data, the characteristic parameters of the equivalent model of the secondary frequency regulation process are identified to construct the secondary frequency regulation characteristic model of the thermal power units. The steps of analysis, construction, solution and effect analysis of the secondary frequency regulation characteristic model of the thermal power units are as follows:

[0068] (1) Analyze the secondary frequency regulation response characteristics of thermal power units. For the convenience of analysis, the AGC frequency regulation response characteristics of the units are analyzed based on the adjustment time. The adjustment time corresponds to the duration of the thermal power unit tracking the AGC command during the AGC response process. The length of the adjustment time can reflect the comprehensive performance of the adjustment rate and response time. Based on the analysis of historical data, it can be seen that when the AGC issues a command, the adjustment time is positively correlated with the adjustment intensity. Figure 2 FIG. 1 is a schematic diagram showing the influence of adjustment intensity on adjustment time according to an exemplary embodiment. Figure 2 As shown, the larger the power command amplitude ΔP is, the darker the corresponding red is, and the longer the corresponding thermal power unit adjustment time is.

[0069] (2) Classification of operating conditions based on regulation intensity. Under different operating conditions, the unit response characteristics are different, and regulation intensity is the main influencing factor of the response characteristics of thermal power units. In this application, other minor factors are ignored and the unit operating conditions are classified based on regulation intensity. Assume that the minimum and maximum values ​​of regulation intensity are P s_min and P s_max , if the interval n 1 The regulation intensity can be divided into [(P s_min , P s_min +n 1 ), (P s_min +n 1 , P s_min +2n 1 ),…(Ps_min +kn 1 -n 1 , P s_min +kn 1 )、(P s_min +kn 1 , P s_max )], each interval is a working condition. The equivalent regulation intensity under each working condition is set to the average value of the upper and lower limits of the regulation intensity of the working condition.

[0070] (3) Characterization of the frequency regulation response characteristics of thermal power units. The frequency regulation characteristics of thermal power units are characterized by the secondary frequency regulation response curve of thermal power units. According to the secondary frequency regulation response curve of thermal power units under different operating conditions, the least square method is used to extract the secondary frequency regulation response characteristics, and the unit output is integrated to obtain the unit frequency regulation response characteristic curve. Under each operating condition, the initial output time and initial time of the actual response curve of the thermal power unit are set to the same value, and an appropriate command duration threshold range is set ( T d , T u ), filter out valid tracking instructions according to the threshold range. Invalid instructions refer to AGC instructions that have a short duration or cannot be effectively tracked during the adjustment period.

[0071] After filtering out the effective instructions, the corresponding response characteristic curve power is obtained according to the effective adjustment process. Taking the i-th working condition as an example, assuming that the number of effective instruction sampling points under the i-th working condition is M i , the mth sampling time is T m ,, a total of N i An effective regulatory process, n The output sequence of thermal power units corresponding to an effective regulation process is (P G,i,1 ,P G,i,2 ,…,P G,i,Mi ). The output of the thermal power units under the effective instructions is superimposed and the average value is taken to obtain the power sequence of the response characteristic curve:

[0072] .

[0073] In addition, the more the amount of operating data under each operating condition, the more instructions that meet the conditions are usually, and the resulting response characteristic curve can better reflect the characteristics of the thermal power unit.

[0074] (4) Construct a secondary frequency regulation characteristic model for thermal power units. Based on the AGC command characteristics and unit response characteristics, a second-order system that can adaptively modify parameters online to reflect different response characteristics is adopted. It can be specifically expressed as:

[0075]

[0076] Among them, G 2 (*) is the transfer function of the response characteristics of the thermal power unit, is the natural frequency of the second-order system, is the damping of the second-order system. The input of the transfer function is the regulated power, and the output is the actual regulation process of the thermal power unit in response to the regulated power. Figure 3 is a schematic diagram of a secondary frequency regulation response characteristic model of a thermal power unit according to an exemplary embodiment. Figure 3 As shown in the figure, the secondary frequency regulation response characteristic model of thermal power units can adjust the adaptive parameters in the model according to the real-time AGC instructions and historical data. .

[0077] The secondary frequency regulation characteristic model of thermal power units constructed in this application adopts a second-order system, which is the simplest system except for the first-order system. However, although the first-order system has a simple structure, it does not contain overshoot, has strong inherent characteristics and cannot modify parameters online. The second-order system can change its response characteristics by modifying the damping online, and this application divides each response process into three sections, each section corresponding to different damping, so as to correspond to different response characteristics, thereby effectively improving the identification effect of the secondary frequency regulation characteristic model of thermal power units and reducing deviations.

[0078] (5) Identification effect measurement index of the secondary frequency regulation characteristic model of thermal power units. With reference to the "Implementation Rules for Auxiliary Service Management of Grid-connected Power Plants in North China" and the "Implementation Rules for Grid-connected Operation Management", the identification effect is measured by the regulation performance and regulation time before and after identification. Since the duration of the response process of thermal power units under different working conditions is different, the least squares method is used, combined with the actual data characteristics and fitting effect, and the average square of the deviation is obtained by taking the average of the square of the deviation through the number of sampling points. The identification effect is measured based on the average square of the deviation.

[0079]

[0080] Among them, F 1 represents the mean square deviation, t represents the sampling time, P * (t) means The actual response characteristic curve output power value of the thermal power unit at the moment t, P(t) represents the actual output power value simulated by the thermal power unit model at the moment t, and m is the number of sampling points. In this way, the identification effect of the secondary frequency regulation characteristic model of the thermal power unit is measured.

[0081] (6) Adaptive parameter identification process of secondary frequency regulation characteristic model of thermal power unit. Natural frequency under different operating conditions Same, determined based on experience Between 0.1 and 0.3, in this application is set to 0.2, but It can be set according to specific application scenarios or experimental experience, and is not limited to the scope listed in this application. When a response process only uses a specific damping, its inherent characteristics will affect the fitting effect, so a response process is divided into three sections according to the instruction strength. Figure 4 is a schematic diagram of a thermal power unit response process segmented according to an exemplary embodiment, such as Figure 4 As shown in the figure, in order to balance the response command strength of each stage and improve the recognition effect, the ratio of each segment is set to 2:2:1 according to the command strength, and the damping value of each segment is ξ 1 ,ξ 2 ,ξ 3 .

[0082] The goal is to minimize the average square deviation, and the damping value ξ 1 ,ξ 2 ,ξ 3 As the decision variable, the damping value ξ at different stages is determined by optimization algorithms such as ant colony algorithm and particle swarm algorithm. 1 ,ξ 2 ,ξ 3 In this application, a particle swarm algorithm is used to solve the adaptive parameters ξ corresponding to different stages under different working conditions. 1 ,ξ 2 ,ξ 3 .

[0083] The hybrid energy storage system includes battery energy storage system (BESS) and flywheel energy storage (FESS). Figure 5 is a schematic diagram of a hybrid energy storage system model according to an exemplary embodiment. Figure 5 As shown, P bref (s) is the power allocation command output of BESS, P b (s) is the actual response output of BESS; P fref (s) is the power allocation command output of FESS, P f (s) is the actual response output of FESS; P g (s) is the real-time output of the thermal power unit; E bN is the rated power of BESS, E fN is the rated power of FESS; SOC b0 is the initial state of charge of BESS, SOC f0 is the initial state of charge of FESS; SOC b is the real-time state of charge of BESS, SOC f is the real-time charge state of FESS; G b (s) is the simplified transfer function model of BESS, Gf (s) is the simplified transfer function model of FESS. When BESS and FESS participate in AGC frequency modulation, there is a certain time delay during the charge and discharge process while tracking the AGC command signal. The full-power response times are in the order of seconds and milliseconds respectively. For the convenience of analysis, G b (s) and G f (s) are simplified to first-order inertia links, which can be specifically expressed as:

[0084]

[0085] Among them, G b (s) is the simplified transfer function model of BESS, G f (s) is the simplified transfer function model of FESS, and T b is the response time constant of BESS, and T f is the response time constant of FESS.

[0086] Figure 6 is the flowchart of a coordinated frequency modulation method for a thermal power unit and an energy storage system provided by an embodiment of the present application. As Figure 6 shown, the method includes:

[0087] Step S101, obtain the mapping relationship between the AGC command and the SOC state of the battery energy storage and the decision variable, and pre-allocate the output of the thermal power unit and the output of the energy storage system through the AGC command, the mapping relationship, and the secondary frequency modulation model of the thermal power unit.

[0088] Optionally, on the basis of the original AGC control of the thermal power unit, a thermal power and energy storage coordination controller is added to the thermal power and energy storage collaborative system, which is used to allocate the output of the thermal power unit and the processing of the energy storage system according to the AGC command and the hybrid energy storage state, and determine the frequency modulation command of the thermal power unit and the frequency modulation command of the hybrid energy storage system. In this way, by changing the control strategy of the original AGC controller of the thermal power unit and adjusting the command received by the thermal power unit, the thermal power unit and the energy storage system participate in frequency modulation协同, which can effectively reduce the frequency modulation burden of the unit, reduce unit wear, power generation, and pollutant emissions, and is beneficial to improving the flexibility of the thermal power unit.

[0089] Optionally, set the threshold range of the SOC state of the battery energy storage and the threshold range of the amplitude of the AGC command power. Assume that the amplitude of the AGC command power is expressed as ΔP ref , Z1 represents the maximum value of the amplitude of the AGC command power, and Z0 represents the minimum value of the amplitude of the AGC command power. When ΔP ref >Z1, the thermal power unit fully responds (or responds in a large proportion); when ΔP ref <Z0, the thermal power unit does not respond; Table 1 shows the proportion of the thermal power unit responding to the AGC command. When Z0 < ΔP refWhen Z1, the thermal power unit responds according to the preset mapping relationship in Table 1.

[0090] Table 1 Response ratio of thermal power unit to AGC command (a ≤ b ≤ c)

[0091]

[0092]

[0093] As shown in Table 1, the SOC state of the BESS is between [0.1, 0.9], the lower warning area is between [0.1, 0.3], the upper warning area is between [0.7, 0.9], and the normal area is between [0.3, 0.7]. Different SOC ranges correspond to different response ratios. In addition, it should be noted that both the SOC threshold range of the BESS and the SOC range corresponding to the regulation ratio can be set according to the model characteristics in the actual application scenario, and are not limited to the ranges listed in Table 1.

[0094] In one example, step S101 includes:

[0095] Step S1011, if the power amplitude of the AGC command is within the preset range, determine the response ratio of the thermal power unit according to the mapping relationship. Optionally, when the power amplitude of the AGC command is within the preset range, determine the response ratio of the thermal power unit according to the mapping relationship between the SOC state of the battery energy storage and the decision variable in step S101.

[0096] Step S1012, generate a frequency modulation command for the thermal power unit according to the ratio, and obtain the output of the thermal power unit based on the frequency modulation command of the thermal power unit according to the secondary frequency modulation model of the thermal power unit. Optionally, generate a frequency modulation command for the thermal power unit by the fire-storage system coordination controller according to the frequency modulation ratio of the thermal power unit, and obtain the output of the thermal power unit through the secondary frequency modulation model.

[0097] In one example, the secondary frequency modulation characteristic model of the thermal power unit in step S1012 is configured to: segment the response process of the thermal power unit according to the regulation intensity, and each segment corresponds to different adaptive parameters to reflect different response characteristics.

[0098] In one example, the secondary frequency modulation characteristic model of the thermal power unit in step S1012 is configured to be obtained in the following way:

[0099] Determine the regulation intensity according to the AGC command, divide the operating conditions of the thermal power unit according to the regulation intensity, and obtain the secondary frequency modulation response information of the thermal power unit under each condition.

[0100] The target adjustment process is selected according to the preset time threshold and the response information, and the response characteristic information is obtained according to the target adjustment process and the corresponding thermal power unit output. The target adjustment process is an AGC instruction that is within the preset time threshold and can be effectively tracked.

[0101] The secondary frequency regulation characteristic model of the thermal power unit is constructed according to the AGC command and response characteristic information. The secondary frequency regulation characteristic model of the thermal power unit is solved by the optimization algorithm to obtain the adaptive parameters of each section.

[0102] The secondary frequency regulation characteristic model of the thermal power unit has been described in detail before step S101 when analyzing the secondary frequency regulation response characteristics of the thermal power unit, and will not be described again here.

[0103] Step S1013, converting the AGC instruction into a frequency regulation demand signal, and obtaining the energy storage system frequency regulation demand signal according to the frequency regulation demand signal and the output of the thermal power unit. A Convert it into a frequency modulation demand signal, and compare the frequency modulation demand signal with the output P of the thermal power unit. G The power deviation is used as the frequency regulation demand signal P of the energy storage system E .

[0104] In this way, the output of thermal power units and energy storage system processing are allocated, and the frequency regulation instructions of thermal power units and hybrid energy storage systems are determined. The thermal power units and energy storage systems participate in frequency regulation in a coordinated manner, thereby effectively reducing the frequency regulation burden of the units, reducing unit wear, power generation and pollutant emissions, and helping to improve the flexibility of thermal power units.

[0105] Step S102, allocating the energy storage system output into battery energy storage output and flywheel energy storage output according to preset rules, and constraining the output power of the battery energy storage output and the flywheel energy storage output according to the SOC states of the battery energy storage and the flywheel energy storage during the allocation process.

[0106] Optionally, considering that the maximum charge and discharge times of flywheel energy storage can reach more than 10 million times, the flywheel energy storage equipment usually does not need to be replaced within 20 years. Therefore, considering the cost issue, the output of the energy storage system is preferentially allocated to the flywheel energy storage output. At the same time, when the energy storage system responds to the AGC frequency regulation demand to output, if it always outputs at rated power and the trend is close to the maximum or minimum value, it may cause the energy storage capacity to be saturated or exhausted, affecting the regulation effect. Therefore, based on the safety and stability considerations during regulation, it is assumed that the charging and discharging power of the battery energy storage and the flywheel energy storage is constrained according to the battery SOC.

[0107] In one example, step S102 includes:

[0108] Step S201, according to preset rules, the battery energy storage output at the first target moment is determined according to the SOC-related parameters of the battery energy storage, the frequency regulation demand signal of the energy storage system and the rated power of the battery energy storage, and the flywheel energy storage output at the first target moment is determined according to the SOC-related parameters of the flywheel energy storage, the frequency regulation demand signal of the energy storage system and the rated power of the flywheel energy storage.

[0109] Optionally, the preset rule is to preferentially allocate the energy storage system output to the flywheel energy storage output, and the battery energy storage output can be specifically expressed as:

[0110]

[0111] Among them, P b (t) is t The battery energy storage output at the time, S b (t) is t The SOC value of BESS at the moment, S bmin is the lower limit of SOC of BESS, S bmax is the upper limit of BESS SOC, P bN is the rated power of BESS, P E It is the frequency modulation demand signal for the energy storage system (i.e. the output of the energy storage system).

[0112] The flywheel energy storage output can be specifically expressed as:

[0113]

[0114] Among them, P f (t) is t The flywheel energy storage output at the time, S f (t) is t The SOC value of FESS at the moment, S fmin is the lower limit of SOC of FESS, S fmax is the upper limit of SOC of FESS, P fN is the rated power of FESS, P E It is the frequency modulation demand signal for the energy storage system (i.e. the output of the energy storage system).

[0115] Step S202, determining the SOC of the battery energy storage at the second target moment according to the rated capacity, charging efficiency and discharging efficiency of the battery energy storage, the SOC at the first target moment and the battery energy storage output, and determining the SOC of the flywheel energy storage at the second target moment according to the rated capacity, charging efficiency and discharging efficiency of the flywheel energy storage, the SOC at the first target moment and the flywheel energy storage output.

[0116] Optionally, during the output of the battery energy storage and the flywheel energy storage, the SOC of the battery energy storage and the flywheel energy storage continuously changes. d , or charging time Δtc After that, the SOC of BESS can be expressed as:

[0117]

[0118] Among them, S b (t+Δt d ) represents the SOC of the BESS at the second target time after discharge, is the discharge efficiency of BESS, E bN is the rated capacity of BESS, t is the first target time, P b (t) is t The battery storage output at the time. b (t+Δt c ) represents the SOC of the BESS at the second target time after charging, is the charging efficiency of BESS.

[0119] After the FESS has been discharged for a period of time Δt d , or charging time Δt c After that, the SOC of FESS can be expressed as:

[0120]

[0121] Among them, S f (t+Δt d ) represents the SOC of the FESS at the second target time after discharge, is the discharge efficiency of FESS, E fN is the rated capacity of FESS, t is the first target time, P f (t) is t The battery storage output at the time. f (t+Δt c ) represents the SOC of the FESS at the second target time after charging, is the charging efficiency of FESS.

[0122] Step S203, constraining the output power of the battery energy storage output process according to the SOC, maximum charge and discharge output, maximum battery energy storage and minimum battery energy storage of the battery energy storage at the second target moment, and constraining the output power of the flywheel energy storage output process according to the SOC, maximum charge and discharge output, maximum flywheel energy storage and minimum flywheel energy storage of the flywheel energy storage at the second target moment

[0123] When the energy storage system responds to the AGC frequency regulation demand and outputs power, if the battery energy storage or flywheel energy storage has been outputting at the rated power and the trend is close to the maximum or minimum value, it is very likely to cause the energy storage capacity to be saturated or exhausted, affecting the regulation effect. Therefore, it is necessary to constrain the charging and discharging power of the battery energy storage and flywheel energy storage when they are output. In this application, a quadratic function curve is selected to constrain the output power of the energy storage system. The constraint expression of the battery energy storage is as follows:

[0124]

[0125] in, Indicates the discharge output power of the battery energy storage, Indicates the charging output power of the battery energy storage, Indicates the maximum battery energy storage, Indicates the minimum battery storage energy, Indicates the minimum warning value of battery energy storage. Indicates the highest warning value of battery energy storage, P bm is the maximum charge and discharge power of battery energy storage, SOC b (t) represents the SOC of the battery energy storage at time t during the charging and discharging process.

[0126]

[0127] in, represents the discharge output power of the flywheel energy storage, represents the charging output power of the flywheel energy storage, Indicates the maximum flywheel energy storage, represents the minimum flywheel energy storage, Indicates the minimum warning value of flywheel energy storage, Indicates the maximum warning value of flywheel energy storage, P fm is the maximum charge and discharge power of flywheel energy storage, SOC f (t) represents the SOC of the flywheel energy storage at time t during the charging and discharging process.

[0128] Step S103, based on the output of the thermal power unit, the battery energy storage output and the flywheel energy storage output, the investment cost and the frequency regulation benefit of the energy storage system are determined, and an economic model is constructed according to the investment cost and the frequency regulation benefit of the energy storage system, and the target decision variables are solved with the goal of maximizing the benefit of the economic model.

[0129] Optionally, the economic benefits of each allocation method are calculated based on the pre-allocated thermal power unit output, battery energy storage output, and flywheel energy storage output, and the value of the target decision variable corresponding to the optimal allocation strategy when the economic benefit is maximized is solved. The Hippo optimization algorithm is used in the solution. The Hippo optimization algorithm adaptively adjusts the resolution and search speed of the search space to quickly and accurately find the optimal solution, and has the characteristics of fast convergence speed and high solution accuracy.

[0130] In one example, the investment cost in step S103 includes average annual configuration cost, average annual replacement cost, operation and maintenance cost, failure loss cost, power loss cost, decommissioning disposal cost and recovery benefit.

[0131] (1) Determine the average annual configuration cost based on the unit power investment cost, unit capacity investment cost, rated power, rated capacity, one-time cash factor, base discount rate and project operation cycle of battery energy storage and flywheel energy storage.

[0132] Optionally, the average annual configuration cost is the average annual fixed investment in the construction phase, including power cost and capacity cost. cap It can be specifically expressed as:

[0133]

[0134]

[0135] Among them, C pb represents the unit power investment cost of BESS, P Nb Indicates the rated power of BESS, C eb represents the BESS unit capacity investment cost, E Nb Indicates the rated capacity of BESS, C pf represents the unit power investment cost of FESS, P Nf Indicates the rated power of FESS, C ef represents the FESS unit capacity investment cost, E Nf represents the rated capacity of FESS, γ CRF represents the cash coefficient of a one-time payment, γ represents the base discount rate; T rt Indicates the project operation cycle.

[0136] (2) Determine the average annual replacement cost based on the unit power investment cost, unit capacity investment cost, rated power, rated capacity and the number of replacements during the project operation cycle.

[0137] Optionally, the average annual replacement cost of the energy storage system is mainly reflected in the battery energy storage system. The operating life of BESS is mainly related to the number of charge and discharge times, and the cost of replacing the equipment needs to be calculated. The maximum charge and discharge times of FESS can reach more than 10 million times, which can basically ensure that there is no need to replace the equipment within 20 years. Therefore, the average annual replacement cost of the energy storage system C rep It can be specifically expressed as:

[0138]

[0139] Among them, C pbrepresents the unit power investment cost of BESS, P Nb Indicates the rated power of BESS, C eb represents the BESS unit capacity investment cost, E Nb Indicates the rated capacity of BESS, n b Indicates the number of replacements during the project operation cycle, Indicates the cash factor for a lump sum payment.

[0140] (3) Determine the operation and maintenance costs based on the rated power, rated capacity, maintenance cost per unit power and maintenance cost per unit capacity of the battery energy storage and flywheel energy storage.

[0141] Optionally, the operation and maintenance cost represents the funds dynamically invested to ensure the normal operation of the energy storage system within its service life, which usually includes the unit power operation and maintenance cost and the unit capacity maintenance cost. pm It can be specifically expressed as:

[0142]

[0143] Among them, C pmb represents the maintenance cost per unit power of BESS, P Nb Indicates the rated power of BESS, C emb represents the maintenance cost per unit capacity of BESS, E Nb Indicates the rated capacity of BESS, C emf represents the maintenance cost per unit capacity of FESS, E Nf Indicates the rated capacity of FESS, C pmf represents the maintenance cost per unit power of FESS, P Nf Indicates the rated power of the FESS.

[0144] (4) Determine the failure loss cost based on the average annual number of failures, average failure handling cost, average annual energy storage charging and discharging capacity, average annual power outage duration and average annual ancillary service market electricity price.

[0145] Optionally, the failure loss cost refers to the economic loss caused by the failure of the energy storage device, including the failure handling cost and the power outage loss cost. F It can be specifically expressed as:

[0146]

[0147] Where N is the average annual failure rate of energy storage equipment, c F is the average fault handling cost, W is the average annual energy storage charge and discharge capacity, T off is the average annual power outage duration of energy storage equipment, and e is the average annual auxiliary service market electricity price.

[0148] (5) Determine the power loss cost based on the battery energy storage output, flywheel energy storage output, unit price of lost power, and charging and discharging efficiencies of battery energy storage and flywheel energy storage.

[0149] Optionally, the power loss cost refers to the power cost caused by the energy storage system losing part of the power due to the problem of charging and discharging efficiency. Q It can be specifically expressed as:

[0150]

[0151] Among them, P Q Indicates the unit price of lost electricity, P b (t) is t The battery energy storage power at the moment, represents the discharge efficiency of BESS, P f (t) is the flywheel energy storage power at time t, represents the discharge efficiency of FESS, represents the charging efficiency of BESS, Indicates the charging efficiency of FESS.

[0152] (6) The decommissioning and disposal cost is determined based on the decommissioning and disposal cost per unit power, the decommissioning and disposal cost per unit capacity, the cash factor of the one-time payment, the number of replacements within the project operation cycle, the rated power of the battery energy storage, and the rated capacity of the battery energy storage.

[0153] Optionally, the decommissioning cost refers to the cost of harmless treatment and recycling of battery energy storage equipment after it is scrapped during its entire life cycle. d It can be specifically expressed as:

[0154]

[0155] Among them, C pd is the unit power decommissioning cost, P rated Indicates the rated power of BESS, C sd is the decommissioning cost per unit capacity, S rated Indicates the rated capacity of BESS, n b Indicates the number of replacements during the project operation cycle, Indicates the cash factor for a lump sum payment.

[0156] (7) The recycling benefit is determined based on the recycling revenue per MW of battery energy storage, the weight of lithium phosphate batteries per MW, the metal price, the metal content per unit weight, the rated power of the battery energy storage, the life cycle and the discount rate.

[0157] Alternatively, recycling revenue refers to the revenue obtained from processing useful substances separated from waste into reusable products. The lithium iron phosphate battery energy storage used in this article can obtain compounds of metals such as cobalt and lithium from waste lithium-ion batteries for reuse after the end of its operating life. recyle It can be specifically expressed as:

[0158]

[0159] Optionally, P N Indicates the rated power of BESS; R metal represents the recovery income of BESS per MW, which is set at RMB 42,130 / t in this application, r represents the benchmark discount rate; N y represents the project operation cycle of BESS; t metal represents the weight of lithium phosphate batteries per megawatt, which is set to 8.3t in this application; n is the number of types of recyclable metals; R metali It represents the price of metal i, in ten thousand yuan / t; It represents the content of metal i in the energy storage battery per unit weight, in %. It should be noted that the recovery income per megawatt of battery energy storage and the weight of lithium phosphate batteries per megawatt set in this application can be set according to the actual project operation conditions, and are not limited to the values ​​listed in this application.

[0160] Based on the above cost analysis, the investment cost can be expressed as:

[0161] C ess = C cap + C rep + C pm + C F + C Q + C d — R recyle .

[0162] In one example, the frequency regulation benefits of the energy storage system in step S103 include: direct benefits of regulation performance compensation, indirect benefits of equivalent unit wear reduction costs, indirect benefits of equivalent reductions in system power generation fuel costs, and indirect benefits of equivalent reductions in system power generation pollution costs.

[0163] (1) Determine the direct benefits of regulation performance compensation based on the total regulation depth of the thermal power units per day, the comprehensive regulation performance index, and the compensation price of AGC frequency regulation.

[0164] Optionally, the direct income from frequency regulation market compensation is divided into regulation performance compensation income and AGC capacity compensation income. All power generation units that provide qualified AGC services can obtain corresponding AGC capacity compensation fees. The increase or decrease of energy storage systems is expected to have little impact on AGC capacity compensation fees, and the increase in frequency regulation income is mainly reflected in the increase in regulation performance compensation income. Regulation performance compensation income R f1 It can be specifically expressed as:

[0165]

[0166] in, Indicates the total regulation depth of the unit on day j, represents the comprehensive regulation performance index of the unit on the jth day, Y AGC The price to compensate for the AGC FM performance.

[0167] (2) Determine the indirect benefits of equivalent unit wear reduction costs based on the proportion of wear caused by thermal power units participating in secondary frequency regulation to the total losses and the total loss costs of thermal power units.

[0168] Alternatively, in order to adapt to frequent load fluctuations and output fluctuations of renewable energy, thermal power units need to quickly increase or decrease loads in a short period of time. Frequent frequency modulation services will cause wear and tear of unit equipment, seriously damage the service life of thermal power unit equipment, increase the frequency of thermal power unit maintenance and unplanned downtime, cause economic losses to thermal power unit operators and affect the power quality of the power system. It is extremely difficult to directly explore the loss of secondary frequency modulation to unit wear. Through research, it is known that the total loss cost S of a thermal power unit within a certain period of time is f , and the adjustment mileage of the thermal power unit in response to the secondary frequency regulation is the main factor affecting the wear of the unit. The greater the frequency regulation mileage of the thermal power unit, the greater the secondary frequency regulation loss of the thermal power unit. The equivalent wear cost corresponding to the annual average secondary frequency regulation of the thermal power unit R f2 It can be specifically expressed as:

[0169]

[0170] Among them, S f It represents the total loss cost of the thermal power unit within a certain period of time. The proportion of wear and tear caused by thermal power units participating in secondary frequency regulation to the total wear and tear.

[0171] (3) Determine the indirect benefits of equivalent reduction in system power generation fuel costs based on the frequency regulation discharge power, the amount of fuel required per unit of power generation, the unit price of fuel and the cash coefficient of the one-time payment.

[0172] Optionally, the thermal power plant is equipped with BESS to assist the frequency regulation of thermal power units, which can reduce the frequency regulation output of thermal power units, thereby reducing the fuel cost required for the corresponding power generation. Therefore, it is equivalent to the indirect benefit of reducing the system power generation fuel cost, and the average annual reduction in power generation fuel cost is R f3 It can be specifically expressed as:

[0173]

[0174] Among them, E t is the frequency modulation discharge amount of energy storage on the tth day, C fuel is the fuel unit price, W fuel is the amount of fuel required for unit power generation, γ CRF Indicates the cash factor of a lump sum payment.

[0175] (4) Determine the indirect benefits of equivalent reduction in the system's power generation and emission costs based on the emission costs of nitrogen oxides, sulfur dioxide and carbon dioxide required for unit power generation, the cash coefficient of the one-time payment and the frequency modulation discharge electricity.

[0176] Optionally, the thermal power plant is equipped with BESS to assist the thermal power unit frequency regulation to reduce the unit frequency regulation output, thereby achieving greenhouse gas emission reduction benefits. Therefore, it is equivalent to the indirect benefit of reducing the system power generation and pollution emission costs. The average annual reduction in power generation and pollution emission costs is R f4 It can be specifically expressed as:

[0177]

[0178] in, The emission fee of nitrogen oxides required for each unit of electricity generated is set at 10.074 yuan / MWh in this application; The emission fee of sulfur dioxide required for each unit of electricity generated is 2.671 yuan / MWh; E is the emission cost of carbon dioxide per unit of electricity generated, 18.669 yuan / MWh; t is the frequency regulation discharge amount of energy storage on the tth day; The emission fees of various greenhouse gases involved in this application can be set according to the specific project operation conditions and are not limited to the examples listed in this application.

[0179] Based on the above analysis of the benefits of energy storage systems participating in frequency regulation, the total energy storage system frequency regulation benefits can be expressed as:

[0180] .

[0181] In step S103, an economic model is constructed based on the investment cost and the frequency regulation benefit of the energy storage system, which can be specifically expressed as:

[0182]

[0183] The constraint condition is 0≤a≤b≤c≤1. In this way, after pre-allocating the output of thermal power units, battery energy storage output and flywheel energy storage output, the economic benefits are determined based on the allocation strategy. And the target decision variables are iteratively solved with the goal of maximizing economic benefits to obtain the optimal allocation strategy. In this way, on the basis of ensuring the frequency regulation effect, the frequency regulation economy is taken into account to improve the frequency regulation performance.

[0184] Step S104, determining a frequency regulation instruction of the thermal power unit according to the target decision variable and the AGC instruction, and performing frequency regulation through the secondary frequency regulation characteristic model of the thermal power unit based on the frequency regulation instruction of the thermal power unit.

[0185] As an example, the frequency regulation method proposed in this application is verified and analyzed based on the AGC instructions and actual power operation data of a thermal power unit with an installed capacity of 330MW in a power plant. Table 2 is a table of relevant parameters of the frequency regulation method of the thermal power unit and the energy storage system.

[0186] Table 2

[0187]

[0188]

[0189]

[0190] Table 3 is a table of parameters related to thermal power units and their regulation performance.

[0191] Table 3

[0192]

[0193]

[0194] First, the secondary frequency regulation model of the thermal power unit is verified. The parameters in the secondary frequency regulation model of the thermal power unit proposed in this application will be adaptively changed according to the model. n It is set to 0.02 and ξ is set to 0.53 as a special case of the variable parameter model. Figure 7 is a schematic diagram of a model tracking process according to an exemplary embodiment. Figure 7As shown in the figure, the output curve of the parameter identification unit has a high degree of overlap with the actual output curve of the thermal power unit (effectiveness); the output curve of the variable parameter identification unit has a higher degree of overlap with the output of the thermal power unit than the fixed parameter model, and has higher superiority. Considering that the initial states of the output of the variable parameter unit and the fixed parameter unit under each instruction are usually different and cannot be effectively explained by a single instruction, the square sum deviation over a period of time is compared. The average square sum deviation of the output of the variable parameter unit during the period of 0-7200s is calculated to be 1.89, and the average square sum deviation of the fixed parameter is 5.72. The error of the output curve of the variable parameter unit is smaller than that of the fixed parameter unit, and the identification effect is better.

[0195] Verify the method of coordinated frequency regulation of thermal power units and energy storage systems. Compare the method of coordinated frequency regulation of thermal power units and energy storage systems with the units themselves and the conventional full-power strategy in actual projects to verify the effectiveness of the method of coordinated frequency regulation of thermal power units and energy storage systems proposed in this application. Solve it with the Hippo optimization algorithm and get the optimal solution of (a, b, c) = (0.33, 0.52, 0.72). Figure 8 is a schematic diagram showing a comparison of frequency modulation curves according to an exemplary embodiment. Figure 8 As shown, the frequency regulation mileage of the thermal power units corresponding to the frequency regulation method of the thermal power units and energy storage system proposed in this application is significantly reduced, which reduces the pressure of thermal power frequency regulation. And due to the introduction of FESS, it can provide greater power increment support under the condition of sufficient FESS power, thereby improving the frequency regulation effect.

[0196] Table 4 is a comparison table of regulation performance and economy.

[0197] Table 4

[0198]

[0199]

[0200] As shown in Table 4, the full power strategy and the coordinated frequency regulation method of the thermal power unit and the energy storage system proposed in this application are compared with the unit itself. pd The annual average regulation depth D increased by 342,000 MW and -84,000 MW respectively. G 0 MW and 1.037 million MW respectively; G AGG The cost of thermal power unit loss R f3 Reduced by 6.276 million; investment cost C essThe total economic benefits were RMB 19.234 million and RMB 17.024 million. C ave An increase of 889,000 yuan and 2.463 million yuan respectively. From the perspective of energy storage investment and net income, the method of coordinated frequency regulation of thermal power units and energy storage systems proposed in this application has obvious advantages. At the same time, this example shows that the method of coordinated frequency regulation of thermal power units and energy storage systems proposed in this application is feasible and effective. In addition, it should be noted that this embodiment is only used as an example to verify the effect of the method of coordinated frequency regulation of thermal power units and energy storage systems proposed in this application, and the parameters and specific values ​​of the parameters involved in this application are not limited to the contents listed in this example.

[0201] In summary, the method for coordinated frequency regulation of thermal power units and energy storage systems proposed in this application uses battery energy storage and flywheel energy storage to assist thermal power units in frequency regulation, which reduces the frequency regulation loss of thermal power units on the one hand and improves the frequency regulation effect on the other. At the same time, this application designs a dynamic proportional control strategy between thermal power units and hybrid energy storage, quantifies the frequency regulation loss cost of the units, constructs an economic model of the coordinated system of thermal power units and hybrid energy storage, and optimizes the target decision variables with the goal of maximizing economic benefits through an optimization algorithm. This ensures the economy and frequency regulation effect of dynamic frequency regulation.

[0202] In a second aspect, an embodiment of the present application provides a device for coordinated frequency regulation of a thermal power unit and an energy storage system, and the device is used to implement the method for coordinated frequency regulation of a thermal power unit and an energy storage system of the first aspect. Fig. 9 is a schematic diagram of a structure of a thermal power unit and an energy storage system coordinated frequency regulation device according to an exemplary embodiment. Fig. 9 As shown, the device includes a thermal power unit module 10 and an energy storage module 20, and the energy storage module includes battery energy storage and flywheel energy storage. b The actual response output of battery energy storage; P f is the actual response output of the flywheel energy storage, P A is the AGC instruction, P G Output of thermal power unit, P h Provide power for energy storage modules.

[0203] The thermal power unit and energy storage system coordinated frequency regulation device also includes a thermal storage system coordination controller 30, which is used to determine the thermal power unit frequency regulation instructions, battery energy storage frequency regulation instructions and flywheel energy storage frequency regulation instructions according to the AGC instructions and the status of the energy storage module 20, so that the thermal power unit module, battery energy storage and flywheel energy storage can perform frequency regulation according to the corresponding instructions respectively.

[0204] Optionally, the thermal power unit and energy storage system coordinated frequency regulation device also includes a remote terminal (Remote Terminal Unit, RTU), which receives AGC instructions, converts them into analog signals that can be received by the thermal storage system coordination controller, and sends them to the controller.

[0205] In summary, this application uses battery energy storage and flywheel energy storage to assist thermal power units in frequency regulation, which reduces the frequency regulation loss of thermal power units on the one hand and improves the frequency regulation effect on the other. At the same time, this application designs a dynamic proportional control strategy between thermal power units and hybrid energy storage, quantifies the frequency regulation loss cost of the units, and constructs an economic model of the thermal power units and hybrid energy storage collaborative system. Through the optimization algorithm, the target decision variables are optimized with the goal of maximizing economic benefits. This ensures the economy and frequency regulation effect of dynamic frequency regulation.

[0206] In a third aspect, the embodiment of the present application provides a coordinated frequency regulation system of a thermal power unit and an energy storage system. Fig.10 is a schematic diagram of a structure of coordinated frequency regulation of a thermal power unit and an energy storage system according to an exemplary embodiment. Fig.10 As shown, the system includes:

[0207] The first allocation module 100 is used to obtain the AGC instruction and the mapping relationship between the SOC state of the battery energy storage and the decision variable, and pre-allocate the output of the thermal power unit and the output of the energy storage system through the AGC instruction, the mapping relationship and the secondary frequency regulation model of the thermal power unit.

[0208] The second allocation module 200 is used to allocate the energy storage system output into battery energy storage output and flywheel energy storage output according to preset rules, and constrain the output power of the battery energy storage output and the flywheel energy storage output according to the SOC status of the battery energy storage and the flywheel energy storage during the allocation process.

[0209] Economic module 300: used to determine the investment cost and frequency regulation benefits of the energy storage system based on the output of thermal power units, battery energy storage output and flywheel energy storage output, build an economic model based on the investment cost and frequency regulation benefits of the energy storage system, and solve the target decision variables with the goal of maximizing the benefits of the economic model.

[0210] Frequency modulation module 400: used to determine the frequency modulation instruction of the thermal power unit according to the target decision variable and the AGC instruction, so that the thermal power unit can perform frequency modulation according to the frequency modulation instruction of the thermal power unit.

[0211] In one example, the first allocation module 100 includes:

[0212] If the power amplitude for responding to the AGC instruction is within a preset range, the response ratio of the thermal power unit is determined according to the mapping relationship.

[0213] The frequency regulation command of the thermal power unit is generated according to the ratio, and the output of the thermal power unit is obtained according to the secondary frequency regulation model of the thermal power unit based on the frequency regulation command of the thermal power unit.

[0214] The AGC command is converted into a frequency regulation demand signal, and the frequency regulation demand signal of the energy storage system is obtained according to the frequency regulation demand signal and the output of the thermal power unit.

[0215] In one example, the second allocation module 200 includes:

[0216] It is used to determine the battery energy storage output at the first target moment according to the SOC related parameters of the battery energy storage, the frequency regulation demand signal of the energy storage system and the rated power of the battery energy storage in accordance with preset rules, and to determine the flywheel energy storage output at the first target moment according to the SOC related parameters of the flywheel energy storage, the frequency regulation demand signal of the energy storage system and the rated power of the flywheel energy storage.

[0217] The SOC of the battery energy storage at the second target moment is determined according to the rated capacity, charging efficiency and discharging efficiency of the battery energy storage, the SOC at the first target moment and the battery energy storage output; the SOC of the flywheel energy storage at the second target moment is determined according to the rated capacity, charging efficiency and discharging efficiency of the flywheel energy storage, the SOC at the first target moment and the flywheel energy storage output.

[0218] The output power during the battery energy storage output process is constrained according to the SOC, maximum charge and discharge output, highest battery energy storage and lowest battery energy storage of the battery energy storage at the second target moment; the output power during the flywheel energy storage output process is constrained according to the SOC, maximum charge and discharge output, highest flywheel energy storage and lowest flywheel energy storage of the flywheel energy storage at the second target moment.

[0219] In one example, the secondary frequency regulation characteristic model of the thermal power unit in the first allocation module 100 is configured to segment the response process of the thermal power unit according to the regulation intensity, and each segment corresponds to different adaptive parameters to reflect different response characteristics.

[0220] In one example, the secondary frequency regulation characteristic model of the thermal power unit in the first allocation module 100 is configured to be obtained in the following manner:

[0221] The regulation intensity is determined according to the AGC instruction, the operating conditions of the thermal power units are divided according to the regulation intensity, and the secondary frequency regulation response information of the thermal power units under each condition is obtained.

[0222] The target adjustment process is selected according to the preset time threshold and the response information, and the response characteristic information is obtained according to the target adjustment process and the output of the corresponding thermal power unit;

[0223] The secondary frequency regulation characteristic model of the thermal power unit is constructed according to the AGC command and response characteristic information. The secondary frequency regulation characteristic model of the thermal power unit is solved by the optimization algorithm to obtain the adaptive parameters of each section.

[0224] In one example, the investment cost in the economic module 300 includes annual average configuration cost, annual average replacement cost, operation and maintenance cost, failure loss cost, power loss cost, decommissioning disposal cost, and recovery benefit.

[0225] The average annual configuration cost is determined based on the unit power investment cost, unit capacity investment cost, rated power, rated capacity, one-time payment cash factor, base discount rate and project operation cycle of battery energy storage and flywheel energy storage.

[0226] The average annual replacement cost is determined based on the unit power investment cost, unit capacity investment cost, rated power, rated capacity and the number of replacements during the project operation cycle of the battery energy storage.

[0227] The operation and maintenance costs are determined based on the rated power, rated capacity, maintenance cost per unit power and maintenance cost per unit capacity of the battery energy storage and flywheel energy storage.

[0228] The failure loss cost is determined based on the average annual number of failures, average failure handling cost, average annual energy storage charging and discharging capacity, average annual power outage duration and average annual ancillary service market electricity price.

[0229] The electricity loss cost is determined based on the battery energy storage output, flywheel energy storage output, unit price of lost electricity, and the charging efficiency and discharging efficiency of battery energy storage and flywheel energy storage.

[0230] The decommissioning and disposal cost is determined based on the decommissioning and disposal cost per unit power, the decommissioning and disposal cost per unit capacity, the cash factor of a one-time payment, the number of replacements within the project operation cycle, the rated power of the battery energy storage, and the rated capacity of the battery energy storage.

[0231] The recycling benefit is determined based on the recycling revenue per megawatt of battery energy storage, the weight of lithium phosphate batteries per megawatt, metal prices, metal content per unit weight, rated power of battery energy storage, life cycle and discount rate.

[0232] In one example, the frequency regulation benefits of the energy storage system in the economic module 300 include: direct benefits from compensation for regulation performance, indirect benefits from equivalent reduction in unit wear costs, indirect benefits from equivalent reduction in system power generation fuel costs, and indirect benefits from equivalent reduction in system power generation pollution costs.

[0233] The direct benefits of regulation performance compensation are determined based on the total regulation depth of thermal power units per day, comprehensive regulation performance indicators, and compensation price of AGC frequency regulation.

[0234] The indirect benefit of reducing the wear cost of equivalent units is determined based on the proportion of wear caused by the thermal power units participating in secondary frequency regulation to the total loss and the total loss cost of the thermal power units.

[0235] The indirect benefit of equivalently reducing the system power generation fuel cost is determined based on the frequency regulation discharge power, the amount of fuel required per unit power generation, the unit price of fuel and the cash coefficient of the one-time payment.

[0236] The indirect benefits of equivalently reducing the system's power generation and emission costs are determined based on the emission costs of nitrogen oxides, sulfur dioxide and carbon dioxide required for unit power generation, the cash coefficient of the one-time payment and the frequency regulation discharge electricity.

[0237] In summary, this application uses battery energy storage and flywheel energy storage to assist thermal power units in frequency regulation, which reduces the frequency regulation loss of thermal power units on the one hand and improves the frequency regulation effect on the other. At the same time, this application designs a dynamic proportional control strategy between thermal power units and hybrid energy storage, quantifies the frequency regulation loss cost of the units, and constructs an economic model of the thermal power units and hybrid energy storage collaborative system. Through the optimization algorithm, the target decision variables are optimized with the goal of maximizing economic benefits. This ensures the economy and frequency regulation effect of dynamic frequency regulation.

[0238] In a fourth aspect, an embodiment of the present application provides an electronic device, Fig.11 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for coordinated frequency modulation of a thermal power unit and an energy storage system provided in the first aspect is implemented. Fig.11 The electronic device 60 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0239] The electronic device 60 may be in the form of a general-purpose computing device, for example, it may be a server device. The components of the electronic device 60 may include but are not limited to: at least one processor 61, at least one memory 62, and a bus 63 connecting different system components (including the memory 62 and the processor 61).

[0240] The bus 63 includes a data bus, an address bus, and a control bus.

[0241] The memory 62 may include a volatile memory, such as a random access memory (RAM) 621 and / or a cache memory 622 , and may further include a read-only memory (ROM) 623 .

[0242] The memory 62 may also include a program / utility 625 having a set (at least one) of program modules 624, such program modules 624 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0243] The processor 61 executes various functional applications and data processing by running the computer program stored in the memory 62, such as the coordinated frequency regulation method of the thermal power unit and the energy storage system provided in the first aspect of the present application.

[0244] The electronic device 60 may also communicate with one or more external devices 64 (e.g., keyboards, pointing devices, etc.). Such communication may be performed via an input / output (I / O) interface 65. Furthermore, the model-generated device may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 66. As shown, the network adapter 66 communicates with other modules of the model-generated device via a bus 63. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the model-generated device, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID (disk array) systems, tape drives, and data backup storage systems, etc.

[0245] It should be noted that although several units / modules or sub-units / modules of the electronic device are mentioned in the above detailed description, this division is merely exemplary and not mandatory. In fact, according to an embodiment of the present invention, the features and functions of two or more units / modules described above can be embodied in one unit / module. Conversely, the features and functions of one unit / module described above can be further divided into multiple units / modules to be embodied.

[0246] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0247] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for coordinated frequency modulation of a thermal power unit and an energy storage system, characterized in that: The method comprises: Obtain the AGC instruction and the mapping relationship between the SOC state of the battery energy storage and the decision variable, and pre-allocate the output of the thermal power unit and the output of the energy storage system through the AGC instruction, the mapping relationship and the secondary frequency regulation model of the thermal power unit. The secondary frequency regulation characteristic model of the thermal power unit is configured to be obtained in the following manner: The response process of the thermal power unit is segmented according to the regulation intensity, and each segment corresponds to different adaptive parameters to reflect different response characteristics, specifically including: determining the regulation intensity according to the AGC instruction, dividing the operating conditions of the thermal power unit according to the regulation intensity, obtaining the secondary frequency regulation response information of the thermal power unit under each condition, screening the target regulation process according to the preset time threshold and the response information, obtaining the response characteristic information according to the target regulation process and the corresponding thermal power unit output, constructing the secondary frequency regulation characteristic model of the thermal power unit according to the AGC instruction and the response characteristic information, solving the secondary frequency regulation characteristic model of the thermal power unit through the optimization algorithm, and obtaining the adaptive parameters of each segment; The output of the energy storage system is allocated to the battery energy storage output and the flywheel energy storage output according to the preset rules. During the allocation process, the output power of the battery energy storage output and the flywheel energy storage output is constrained according to the SOC state of the battery energy storage and the flywheel energy storage. The preset rule is to preferentially allocate the output of the energy storage system to the flywheel energy storage output, wherein the constraint expression of the battery energy storage is as follows: in, Indicates the discharge output power of the battery energy storage, Indicates the charging output power of the battery energy storage, Indicates the maximum battery energy storage, Indicates the minimum battery storage energy, Indicates the minimum warning value of battery energy storage. Indicates the highest warning value of battery energy storage, P bm is the maximum charge and discharge power of battery energy storage, SOC b (t) represents the SOC of the battery energy storage at time t during the charging and discharging process, The constraint expression of flywheel energy storage is as follows: in, represents the discharge output power of the flywheel energy storage, represents the charging output power of the flywheel energy storage, Indicates the maximum flywheel energy storage, represents the minimum flywheel energy storage, Indicates the minimum warning value of flywheel energy storage, Indicates the maximum warning value of flywheel energy storage, P fm is the maximum charge and discharge power of flywheel energy storage, SOC f (t) represents the SOC of the flywheel energy storage at time t during the charging and discharging process; Determine the investment cost and frequency regulation benefit of the energy storage system based on the output of thermal power units, battery energy storage output and flywheel energy storage output, build an economic model based on the investment cost and frequency regulation benefit of the energy storage system, and solve the target decision variables with the goal of maximizing the benefit of the economic model; A frequency regulation instruction of the thermal power unit is determined according to the target decision variable and the AGC instruction, so that the thermal power unit can regulate the frequency according to the frequency regulation instruction of the thermal power unit.

2. The method for coordinated frequency modulation of a thermal power unit and an energy storage system according to claim 1, characterized in that: The output of the thermal power unit and the output of the energy storage system are distributed through the AGC instruction and the mapping relationship, including: In response to the power amplitude of the AGC instruction being within a preset range, determining a response ratio of the thermal power unit according to the mapping relationship; Generate a frequency regulation instruction for the thermal power unit according to the ratio, and obtain the output of the thermal power unit according to a secondary frequency regulation model of the thermal power unit based on the frequency regulation instruction for the thermal power unit; The AGC instruction is converted into a frequency modulation demand signal, and a frequency modulation demand signal of the energy storage system is obtained according to the frequency modulation demand signal and the output of the thermal power unit.

3. The method for coordinated frequency modulation of a thermal power unit and an energy storage system according to claim 2, characterized in that: The energy storage system output is distributed into battery energy storage output and flywheel energy storage output according to preset rules, and during the distribution process, the output power of the battery energy storage output and the flywheel energy storage output is constrained according to the SOC state of the battery energy storage and the flywheel energy storage, including: According to the preset rules, the battery energy storage output at the first target moment is determined according to the SOC-related parameters of the battery energy storage, the frequency regulation demand signal of the energy storage system and the rated power of the battery energy storage; the flywheel energy storage output at the first target moment is determined according to the SOC-related parameters of the flywheel energy storage, the frequency regulation demand signal of the energy storage system and the rated power of the flywheel energy storage; Determine the SOC of the battery energy storage at the second target time according to the rated capacity, charging efficiency and discharging efficiency of the battery energy storage, the SOC at the first target time and the output of the battery energy storage, and determine the SOC of the flywheel energy storage at the second target time according to the rated capacity, charging efficiency and discharging efficiency of the flywheel energy storage, the SOC at the first target time and the output of the flywheel energy storage; The output power during the battery energy storage output process is constrained according to the SOC, maximum charge and discharge output, highest battery energy storage and lowest battery energy storage of the battery energy storage at the second target moment; the output power during the flywheel energy storage output process is constrained according to the SOC, maximum charge and discharge output, highest flywheel energy storage and lowest flywheel energy storage of the flywheel energy storage at the second target moment.

4. The method for coordinated frequency modulation of a thermal power unit and an energy storage system according to claim 1, characterized in that: The investment cost includes the average annual configuration cost, the average annual replacement cost, the operation and maintenance cost, the failure loss cost, the power loss cost, the decommissioning disposal cost and the recovery benefit; Determine the average annual configuration cost based on the unit power investment cost, unit capacity investment cost, rated power, rated capacity, one-time cash factor, base discount rate and project operation cycle of battery energy storage and flywheel energy storage; Determine the average annual replacement cost based on the unit power investment cost, unit capacity investment cost, rated power, rated capacity and number of replacements during the project operation cycle of the battery energy storage; Determine the operation and maintenance costs based on the rated power, rated capacity, maintenance cost per unit power and maintenance cost per unit capacity of the battery energy storage and flywheel energy storage; Determine the failure loss cost based on the average annual number of failures, average failure handling cost, average annual energy storage charging and discharging capacity, average annual power outage duration, and average annual ancillary service market electricity price; Determine the power loss cost based on the battery energy storage output, flywheel energy storage output, unit price of lost power, charging efficiency and discharging efficiency of battery energy storage and flywheel energy storage; The decommissioning disposal cost is determined based on the decommissioning disposal cost per unit power, the decommissioning disposal cost per unit capacity, the cash factor of the one-time payment, the number of replacements within the project operation cycle, the rated power of the battery energy storage, and the rated capacity of the battery energy storage; The recycling benefit is determined based on the recycling revenue per megawatt of battery energy storage, the weight of lithium phosphate batteries per megawatt, metal prices, metal content per unit weight, rated power of battery energy storage, life cycle and discount rate.

5. The method for coordinated frequency modulation of a thermal power unit and an energy storage system according to claim 1, characterized in that: The energy storage system frequency regulation benefits include: direct benefits from regulation performance compensation, indirect benefits from equivalent unit wear reduction costs, indirect benefits from equivalent reductions in system power generation fuel costs, and indirect benefits from equivalent reductions in system power generation pollution costs; Determine the direct benefits of regulation performance compensation based on the total regulation depth of thermal power units per day, comprehensive regulation performance indicators, and compensation price of AGC frequency regulation; Determine the indirect benefits of equivalent unit wear reduction costs based on the proportion of wear caused by thermal power units participating in secondary frequency regulation to total losses and the total loss costs of thermal power units; Determine the indirect benefits of equivalently reducing the system power generation fuel cost based on the frequency regulation discharge power, the fuel quantity required per unit power generation, the fuel unit price and the cash factor of the one-time payment; The indirect benefits of equivalently reducing the system's power generation and emission costs are determined based on the emission costs of nitrogen oxides, sulfur dioxide and carbon dioxide required for unit power generation, the cash coefficient of the one-time payment and the frequency regulation discharge electricity.

6. A frequency modulation device for a thermal power unit and an energy storage system, characterized in that: The device is used to implement the coordinated frequency regulation method of a thermal power unit and an energy storage system according to any one of claims 1 to 5, The device comprises a thermal power unit module and an energy storage module, wherein the energy storage module comprises battery energy storage and flywheel energy storage; The device also includes a thermal energy storage system coordination controller, which is used to determine the thermal power unit frequency modulation instruction, battery energy storage frequency modulation instruction and flywheel energy storage frequency modulation instruction according to the AGC instruction and the status of the energy storage module, so that the thermal power unit module, battery energy storage and flywheel energy storage can perform frequency modulation according to the corresponding instructions respectively.

7. A frequency modulation system for a thermal power unit and an energy storage system, characterized in that: The system comprises: The first allocation module is used to obtain the AGC instruction and the mapping relationship between the SOC state of the battery energy storage and the decision variable, and pre-allocate the output of the thermal power unit and the output of the energy storage system through the AGC instruction, the mapping relationship and the secondary frequency regulation model of the thermal power unit. The secondary frequency regulation characteristic model of the thermal power unit is configured to be obtained in the following manner: The response process of the thermal power unit is segmented according to the regulation intensity, and each segment corresponds to different adaptive parameters to reflect different response characteristics, specifically including: determining the regulation intensity according to the AGC instruction, dividing the operating conditions of the thermal power unit according to the regulation intensity, obtaining the secondary frequency regulation response information of the thermal power unit under each condition, screening the target regulation process according to the preset time threshold and the response information, obtaining the response characteristic information according to the target regulation process and the corresponding thermal power unit output, constructing the secondary frequency regulation characteristic model of the thermal power unit according to the AGC instruction and the response characteristic information, solving the secondary frequency regulation characteristic model of the thermal power unit through the optimization algorithm, and obtaining the adaptive parameters of each segment; The second allocation module is used to allocate the output of the energy storage system into the battery energy storage output and the flywheel energy storage output according to the preset rules. During the allocation process, the output power of the battery energy storage output and the flywheel energy storage output is constrained according to the SOC state of the battery energy storage and the flywheel energy storage. The preset rule is to preferentially allocate the output of the energy storage system to the flywheel energy storage output, wherein the constraint expression of the battery energy storage is as follows: in, Indicates the discharge output power of the battery energy storage, Indicates the charging output power of the battery energy storage, Indicates the maximum battery energy storage, Indicates the minimum battery energy storage, Indicates the minimum warning value of battery energy storage. Indicates the highest warning value of battery energy storage, P bm is the maximum charge and discharge power of battery energy storage, SOC b (t) represents the SOC of the battery energy storage at time t during the charging and discharging process, The constraint expression of flywheel energy storage is as follows: in, represents the discharge output power of the flywheel energy storage, represents the charging output power of the flywheel energy storage, Indicates the maximum flywheel energy storage, represents the minimum flywheel energy storage, Indicates the minimum warning value of flywheel energy storage, Indicates the maximum warning value of flywheel energy storage, P fm is the maximum charge and discharge power of flywheel energy storage, SOC f (t) represents the SOC of the flywheel energy storage at time t during the charging and discharging process; Economic module: used to determine the investment cost and frequency regulation benefits of the energy storage system based on the output of thermal power units, battery energy storage output and flywheel energy storage output, build an economic model based on the investment cost and frequency regulation benefits of the energy storage system, and solve the target decision variables with the goal of maximizing the benefits of the economic model; Frequency modulation module: used to determine the frequency modulation instruction of the thermal power unit according to the target decision variable and the AGC instruction, so that the thermal power unit can perform frequency modulation according to the frequency modulation instruction of the thermal power unit.

8. An electronic device, characterized in that: include Memory, processor, and A computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for coordinated frequency regulation of a thermal power unit and an energy storage system as described in any one of claims 1 to 5 is implemented.

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