Energy storage auxiliary thermal power generating unit frequency control method and system

Abstract

The invention discloses an energy storage assisted thermal power generating unit frequency control method and system, and aims to reduce the time of a thermal power generating unit operating in a deep peak regulation state while improving the frequency modulation qualification rate by using an energy storage system to assist the thermal power generating unit in frequency modulation, thereby improving the overall economic benefit of the unit. According to the method, on the basis of analysis of historical statistical data, the actual frequency modulation capacity of the thermal power generating unit at different load points is combined, the insufficient power part of the thermal power generating unit in the frequency modulation process is calculated, supplement is conducted through the energy storage system, and therefore the frequency modulation qualification rate of the thermal power generating unit is increased. In order to further optimize the combined operation economy of the thermal power generating unit and the energy storage system, an economic model of the combined operation of the thermal power generating unit and the energy storage system is constructed. The model is combined with a power generation plan of the thermal power generating unit, the charging and discharging power of the energy storage system is planned, and deep peak regulation of the thermal power generating unit is reduced to the maximum extent while the frequency modulation task of the thermal power generating unit is completed, so that the overall economy of the thermal power storage combined system is maximized.

Description

Background Art

[0002] In recent years, the penetration rate of new energy in the power system has been continuously increasing, but at the same time, serious phenomena of wind curtailment and photovoltaic curtailment are faced. When the operating point of thermal power units decreases, their frequency regulation ability also decreases, which affects the frequency balancing ability of the power system. For units undergoing flexibility transformation, both their output fluctuations and the ability to quickly respond to various changes have been improved, the load points at which they can operate safely are lower, and they can achieve rapid start-stop and rapid load ramping, greatly enhancing the peak shaving ability.

[0003] Compared with the various dilemmas faced by thermal power units, new types of frequency regulation resources are showing an unprecedented development trend. As the proportion of clean energy in the power grid continues to rise, the randomness and volatility of its power generation have an increasingly significant impact on the power grid. This impact reduces the inertia of the system output, increases the operational uncertainty, makes the operation and control of the power grid more complex, and thus poses a challenge to the stability of the system. Currently, as the cornerstone of the power grid's frequency regulation, thermal power units have limitations such as slow response speed and decreased ramp rate during deep peak shaving operation, and other resources are urgently needed to assist the power system in frequency regulation to ensure the safe operation of the power system. With the continuous development of energy storage technology, it provides a new technical solution for the frequency stability problems caused by grid-connected renewable energy. The role of energy storage systems in grid-connected renewable energy is becoming increasingly prominent. When the actual power generation of clean energy is insufficient, energy storage devices can quickly intervene to provide short-term power supply support for the power system to ensure that the unit output is consistent with the dispatching requirements. When the power generated by the power generation system exceeds the user-side demand, the excess power will be stored through various media such as batteries to avoid power waste and the abandonment of renewable energy. When the power generation of renewable energy cannot meet the demand-side load, the electricity stored in the energy storage system will be released to make up for the energy gap, thus ensuring the stable operation of the power system. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for energy storage-assisted frequency control of thermal power units in view of the above deficiencies in the prior art. On the premise of ensuring the safety and high-efficiency operation of energy storage units and thermal power units, the qualified rate of frequency regulation of thermal power units is improved, the frequency of deep peak shaving of thermal power units is reduced, and the economic benefits of combined frequency regulation of thermal power units and energy storage systems are improved, so as to solve the technical problems of the decline in frequency regulation ability and the reduction of the qualified rate of frequency regulation caused by the deep peak shaving of thermal power units.

[0005] The present invention adopts the following technical solutions: An energy storage-assisted frequency control method for thermal power units, comprising the following steps: Establish a cost model for the combined system of thermal power units and energy storage; Establish an optimization objective function for the cost model of the combined thermal power unit and energy storage system with the best economy; Considering the operating load of the thermal power unit, the load ramping ability, the margin required for energy storage assisted frequency modulation, the state of charge of the energy storage system, and the maximum charge and discharge power of the energy storage system, establish the constraint conditions for the cost model of the combined thermal power unit and energy storage system; Based on the cost model, objective function and constraint conditions of the combined thermal power unit and energy storage system, establish a combined operation economic model of the thermal power unit and energy storage system. By planning the charge and discharge power of the energy storage through the model, improve the qualified rate of frequency modulation of the thermal power unit and achieve deep peak shaving of the thermal power unit.

[0006] Preferably, the construction of the cost model of the combined thermal power unit and energy storage system is specifically as follows: Construct the total operating cost of the system with the coal cost of the thermal power unit, the deep peak shaving cost of the thermal power unit, and the operating cost of the energy storage. Take minimizing the total operating cost of the system and the frequency modulation performance target as the objective function.

[0007] Preferably, the optimization objective function is:

[0008] Among them, To maximize the frequency modulation economic benefit of the combined thermal power unit and battery energy storage system, Is the operating income of the thermal power unit; Is the operating income of the energy storage.

[0009] Preferably, the operating income of the thermal power unit Is:

[0010] The operating income of the energy storage Is:

[0011] Among them, Is the power generation income of the thermal power unit, Is the coal cost of the thermal power unit / 10,000 yuan, Is the additional cost required for oil injection during deep peak shaving of the thermal power unit, Is the penalty cost for the thermal power unit's failure to complete the power generation plan, Is the operating cost of the energy storage, Is the frequency modulation income.

[0012] Preferably, the power generation income of the thermal power unit The coal cost of the thermal power unit The additional cost required for oil injection during deep peak shaving of the thermal power unit The penalty cost for the thermal power unit's failure to complete the power generation plan Are respectively:

[0013]

[0014]

[0015]

[0016] Among them, is the power generation revenue of the thermal power unit; is the planned power generation of the thermal power unit at time t; is the coal consumption cost of the thermal power unit; is the additional cost required for oil injection during deep peak shaving of the thermal power unit; is the penalty cost for the thermal power unit's failure to complete the power generation plan; is the coal coefficient of the thermal power unit; The output of the thermal power unit at time t; is the oil injection volume of the thermal power unit at time t; is the current oil price; is the penalty coefficient for the failure to achieve the power generation plan.

[0017] Preferably, the energy storage operation cost and the frequency modulation revenue are respectively:

[0018]

[0019] Among them, is the fixed operation cost of the energy storage; is the charge-discharge power of the energy storage; is the frequency modulation revenue compensation; is the penalty for frequency modulation non-compliance.

[0020] Preferably, the constraint conditions of the cost model of the combined system of thermal power unit and energy storage include: Power balance constraint:

[0021] Among them, is the power generation plan of the thermal power unit, is the output of the thermal power unit, is the output of the energy storage system; Output power constraint of the thermal power unit:

[0022] Among them, is the minimum output power of the thermal power unit / MW; is the maximum output power of the thermal power unit / MW; Ramp rate constraint of the thermal power unit:

[0023] wherein, is the maximum ramp power of the thermal power unit; Input power constraint of the energy storage system:

[0024] wherein, is the minimum charge and discharge power of the energy storage system; is the maximum charge and discharge power of the energy storage system; State of charge constraint of the energy storage system:

[0025] wherein, is the lower bound of the change in the state of charge of the current energy storage system, is the upper bound of the change in the state of charge of the current energy storage system.

[0026] Preferably, the margin required for energy storage-assisted frequency modulation is calculated as follows: Analyze the historical data of primary frequency modulation and secondary frequency modulation of the thermal power unit, and statistically analyze the power distribution of the frequency modulation tasks of the thermal power unit; analyze the frequency modulation capabilities of the thermal power unit under different loads; calculate the amount of electricity required for the energy storage to make up for the insufficient response of the thermal power unit according to the operation plan of the thermal power unit.

[0027] Preferably, the lower bound of the change in the state of charge of the current energy storage system and the upper bound

[0028]

[0029] wherein, is the frequency modulation margin in the discharging direction of the energy storage system, is the frequency modulation margin in the charging direction of the energy storage system, is the state of charge of the energy storage at the current moment.

[0030] In a second aspect, an embodiment of the present invention provides an energy storage-assisted thermal power unit frequency control system, including: A construction module that establishes a cost model for the combined system of the thermal power unit and the energy storage; A function module that establishes an optimization objective function for the cost model of the combined system of the thermal power unit and the energy storage with optimal economy; The constraint module considers the operating load of the thermal power unit, the load increase and decrease capacity, the margin required for energy storage-assisted frequency regulation, the state of charge of the energy storage system, and the maximum charge and discharge power of the energy storage system, and establishes the constraint conditions for the cost model of the combined system of the thermal power unit and the energy storage. The control module, based on the cost model of the combined system of the thermal power unit and the energy storage, the objective function, and the constraint conditions, establishes an economic model for the combined operation of the thermal power unit and the energy storage system. By planning the charge and discharge power of the energy storage through the model, the qualified rate of frequency regulation of the thermal power unit is improved, and deep peak shaving of the thermal power unit is realized.

[0031] In a third aspect, a computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above energy storage-assisted frequency control method for thermal power units are implemented.

[0032] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium including a computer program. When the computer program is executed by a processor, the steps of the above energy storage-assisted frequency control method for thermal power units are implemented.

[0033] In a third aspect, a chip includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above energy storage-assisted frequency control method for thermal power units are implemented.

[0034] In a fourth aspect, an embodiment of the present invention provides an electronic device including a computer program. When the computer program is executed by the electronic device, the steps of the above energy storage-assisted frequency control method for thermal power units are implemented.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects: An energy storage-assisted frequency control method for thermal power units calculates the unqualified power by statistically analyzing the past frequency control information of thermal power units, reserves this part of the power for energy storage in the planning, and improves the qualified rate of frequency regulation of thermal power units; while ensuring the qualified rate of frequency regulation, it maximizes the reduction of the time for deep peak shaving of thermal power units, thereby improving the economic benefits of the energy storage and thermal power system.

[0036] Furthermore, the input data is relatively easy to obtain and has good timeliness, which can fully reflect the current frequency control requirements of thermal power units.

[0037] Furthermore, the optimized reward function fully reflects the costs and benefits during the operation of thermal power units and energy storage systems.

[0038] Furthermore, by designing a series of constraint conditions, the solution can be made more in line with the actual situation, and a margin is reserved for the energy storage to assist the thermal power unit in frequency control during the day. The safety of the energy storage is improved by restricting the upper and lower limits of the state of charge of the energy storage and the rate of change of the energy storage output. Specifically, when the energy of the energy storage is too low or too high, the service life of the energy storage will be affected, and too rapid a change in output will affect the safety of the energy storage and even cause an impact on the power grid.

[0039] Furthermore, based on the statistical power distribution of historical frequency modulation data, the frequency modulation margin gap of the thermal power unit can be quantified to avoid excessive configuration of the energy storage capacity. By analyzing the frequency modulation capabilities under different load conditions, a curve of unit output - frequency modulation sensitivity is established to enable the energy storage replenishment strategy to match the grid demand in real time. By combining the unit operation plan to predict the frequency modulation demand and optimizing the energy storage charging and discharging time sequence, while reducing the frequency of deep peak shaving of thermal power, the service life of the unit equipment is extended, and the optimal life - cycle cost is achieved. Through data - driven optimization of the energy storage - thermal power coordinated control, both the reliability and economy of frequency modulation are taken into account.

[0040] It can be understood that the beneficial effects of the second to fourth aspects above can refer to the relevant descriptions in the first aspect above, and will not be elaborated here.

[0041] In summary, the method of the present invention improves the economy of the energy storage assisting the thermal power unit in frequency control and deep peak shaving, enhances the support ability of the thermal - energy storage combined system for the grid frequency stability, and maintains the safe and stable operation of the thermal power unit and the power system, on the premise of ensuring the safety and high - efficiency operation of the energy storage unit and the thermal power unit.

[0042] The technical solution of the present invention will be further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0044] Figure 1 It is a schematic diagram of the energy storage assisting the thermal power unit in frequency control and deep peak shaving; Figure 2 It is the optimization result of the day - ahead power distribution; Figure 3 It is the constraint on the state of charge of the energy storage; Figure 4 It is the comparison of the day - ahead state of charge under different frequency modulation margins; Figure 5 It is the comparison of the in - day state of charge under different frequency modulation margins.

[0045] Figure 6 Schematic diagram of a computer device provided by an embodiment of the present invention; Figure 7 Block diagram of an electronic device provided by the present invention according to an embodiment. Specific embodiments

[0046] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

[0047] In the description of the present invention, it should be understood that the terms "include" and "comprise" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0048] It should also be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms.

[0049] It should be further understood that the term " / and" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally represents an "or" relationship between the associated objects before and after.

[0050] It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present invention to describe preset ranges, etc., these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range can also be referred to as the second preset range, and similarly, the second preset range can also be referred to as the first preset range.

[0051] Depending on the context, as used herein, the term "if" may be interpreted as "when" or "while" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if determined" or "if detected (stated condition or event)" may be interpreted as "when determined" or "in response to determining" or "when detected (stated condition or event)" or "in response to detecting (stated condition or event)".

[0052] Various structural schematic diagrams according to the disclosed embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art can additionally design regions / layers with different shapes, sizes, and relative positions according to actual requirements.

[0053] The present invention provides a frequency control method for a thermal power unit assisted by energy storage. While using an energy storage system to assist the thermal power unit in frequency modulation to improve the frequency modulation qualification rate, it reduces the operation time of the thermal power unit in the deep peak shaving state, thereby enhancing the overall economic benefit of the unit. This method relies on the analysis of historical statistical data, combines the actual frequency modulation capabilities of the thermal power unit at different load points, calculates the power shortage part existing in the frequency modulation process of the thermal power unit, and supplements it through the energy storage system, thereby improving the frequency modulation qualification rate of the thermal power unit. To further optimize the economic operation of the combined operation of the thermal power unit and the energy storage system, an economic model for the combined operation of the thermal power unit and the energy storage system is constructed. This model combines the power generation plan of the thermal power unit, plans the charge and discharge power of the energy storage system, ensures that while completing the frequency modulation task of the thermal power unit, it maximally reduces the deep peak shaving of the thermal power unit, thereby achieving the maximization of the overall economy of the combined thermal energy and energy storage system.

[0054] A frequency control method for a thermal power unit assisted by energy storage according to the present invention includes the following steps: S1. Establish a cost model for the combined system of the thermal power unit and the energy storage; The model comprehensively considers the coal cost of the thermal power unit, the deep peak shaving cost of the thermal power unit, the operation and use cost of the energy storage, and the frequency modulation target.

[0055] S2. Establish an optimization objective function with the optimal economy, and the function is the sum of the frequency modulation benefits of the energy storage assisting the thermal power unit and the benefits of the energy storage reducing the deep peak shaving of the thermal power unit; The optimization objective of the model is to maximize the frequency modulation economic benefit of the combined system of the thermal power unit and the battery energy storage.

[0056]

[0057] Wherein, is the operating income of the thermal power unit; is the operating income of the energy storage.

[0058] The income of the thermal power unit includes the income brought by the unit's completion of the power generation plan and its operating costs. The income includes power generation income and energy storage auxiliary frequency modulation income. The power generation income is related to the power generation plan; while the operating costs consist of coal cost, oil injection cost required for deep peak shaving, and penalty cost for failure to track the intraday power generation plan.

[0059]

[0060]

[0061]

[0062]

[0063]

[0064] Among them, is the power generation income of the thermal power unit / 10,000 yuan; is the planned power generation of the thermal power unit at time t / MW; is the coal cost of the thermal power unit / 10,000 yuan; is the additional cost required for oil injection during deep peak shaving of the thermal power unit; is the penalty cost for the thermal power unit's failure to complete the power generation plan / 10,000 yuan; is the coal coefficient of the thermal power unit; is the output of the thermal power unit at time t / MW; is the oil injection volume of the thermal power unit at time t / t; is the current oil price / 10,000 yuan; is the penalty coefficient for failure to achieve the power generation plan.

[0065] The peak shaving process of the thermal power unit is divided into basic peak shaving, deep peak shaving without oil injection, and deep peak shaving with oil injection.

[0066] The basic peak shaving load range is above 40%, the deep peak shaving without oil injection is 35% - 40%, the deep peak shaving with oil injection range is 30% - 35%, and there is no situation with a load below 30%.

[0067] The calculation of the energy storage operating income includes energy storage operating costs and frequency modulation income, specifically:

[0068] Among them, is the energy storage operating cost, is the frequency modulation income.

[0069]

[0070] Among them, is the fixed operating cost of energy storage / 10,000 yuan·MWh -1 ; is the charge and discharge power of energy storage / MW;

[0071] Among them, is the frequency regulation revenue compensation, is the penalty for unqualified frequency regulation.

[0072]

[0073] Among them, is the primary frequency regulation compensation coefficient of the thermal power plant; is the unit compensation price / yuan·MWh-1, taking 200.

[0074]

[0075] Among them, is the penalty coefficient for unqualified primary frequency regulation of the thermal power unit; is the dead zone coefficient of primary frequency regulation assessment of the thermal power unit, defaulting to 1; is the time coefficient of primary frequency regulation assessment of the thermal power unit / h; is the number of unqualified times of primary frequency regulation of the thermal power unit, and whether it is qualified is determined by the primary frequency regulation contribution rate.

[0076] S3. Establish model constraint conditions, comprehensively considering the operating load of the thermal power unit, the load increase and decrease capacity, the margin required for energy storage assisted frequency regulation, the state of charge of the energy storage system, and the maximum charge and discharge power of the energy storage system; The constraint conditions include Power balance constraint:

[0077] Among them, is the power generation plan of the thermal power unit, is the output of the thermal power unit, is the output of the energy storage system.

[0078] Output power constraint of the thermal power unit:

[0079] Among them, is the minimum output power of the thermal power unit / MW; is the maximum output power of the thermal power unit / MW.

[0080] Ramp rate constraint of the thermal power unit:

[0081] Among them, is the maximum ramp rate of the thermal power unit / MW, which is determined by the current operating load of the thermal power unit. When the operating state of the thermal power unit is low, its ramp rate will also decrease.

[0082] Input power constraint of the energy storage system:

[0083] Among them, is the minimum charge-discharge power of the energy storage system / MW; is the maximum charge-discharge power of the energy storage system / MW.

[0084] State of charge constraint of the energy storage system:

[0085] Among them, is the lower bound of the change in the state of charge of the current energy storage system / %, which is related to the current operating state of the thermal power unit; is the upper bound of the change in the state of charge of the current energy storage system / %.

[0086]

[0087]

[0088] Among them, Frequency modulation margin in the discharging direction of the energy storage system / %, which is obtained by statistically analyzing the data of previous primary and secondary frequency modulation commands; Frequency modulation margin in the charging direction of the energy storage system %, and the calculation method is the same as above.

[0089] The margin required for energy storage assisted frequency modulation is calculated as follows: Analyze the historical data of primary and secondary frequency modulation of thermal power units, and statistically analyze the power distribution of frequency modulation tasks of thermal power units; Analyze the frequency modulation capabilities of thermal power units under different loads; According to the operation plan of thermal power units, calculate the amount of electricity required for energy storage to make up for the insufficient response of thermal power units.

[0090] S4. Based on the above cost model, objective function, and constraint conditions, establish a combined operation economic model for thermal power units and energy storage systems. By planning the charge-discharge power of the energy storage through the model, improve the frequency modulation qualification rate of thermal power units, reduce the deep peak shaving of thermal power units, and thus enhance the economy of the combined system.

[0091] While ensuring the frequency modulation qualification rate of thermal power units, the time of deep peak shaving of thermal power units is minimized.

[0092] Those skilled in the art can understand that various aspects of the present invention can be implemented as a system, a method, or a program product. Therefore, various aspects of the present invention can be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or an implementation combining hardware and software aspects, which can be collectively referred to as "circuits", "modules", or "platforms".

[0093] In another embodiment of the present invention, there is provided a frequency control system for a thermal power unit assisted by energy storage, which can be used to implement the above-mentioned frequency control method for a thermal power unit assisted by energy storage. Specifically, the frequency control system for a thermal power unit assisted by energy storage includes a construction module, a function module, a constraint module, and a control module.

[0094] Among them, the construction module establishes a cost model for the combined system of a thermal power unit and energy storage; The function module establishes an optimization objective function for the cost model of the combined system of a thermal power unit and energy storage with the best economy; The constraint module considers the operating load of the thermal power unit, the load increase and decrease capacity, the margin required for energy storage assisted frequency modulation, the state of charge of the energy storage system, and the maximum charge and discharge power of the energy storage system, and establishes constraint conditions for the cost model of the combined system of a thermal power unit and energy storage; The control module, based on the cost model of the combined system of a thermal power unit and energy storage, the objective function, and the constraint conditions, establishes an economic model for the combined operation of the thermal power unit and the energy storage system, and improves the frequency modulation qualification rate of the thermal power unit by planning the charge and discharge power of the energy storage through the model, so as to achieve deep peak shaving of the thermal power unit.

[0095] In another embodiment of the present invention, there is provided a terminal device, which includes a processor and a memory. The memory is used to store a computer program, and the computer program includes program instructions. The processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of the frequency control method for a thermal power unit assisted by energy storage, including: Establish a cost model for a thermal power unit and energy storage combined system; establish an optimization objective function for the cost model of the thermal power unit and energy storage combined system with the optimal economy; consider the operating load of the thermal power unit, the load ramping ability, the margin required for energy storage assisted frequency modulation, the state of charge of the energy storage system, and the maximum charge and discharge power of the energy storage system, and establish the constraint conditions for the cost model of the thermal power unit and energy storage combined system; based on the cost model, objective function, and constraint conditions of the thermal power unit and energy storage combined system, establish an economic model for the combined operation of the thermal power unit and energy storage system, and improve the frequency modulation qualification rate of the thermal power unit by planning the charge and discharge power of the energy storage through the model, so as to achieve deep peak shaving of the thermal power unit.

[0096] In another embodiment of the present invention, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in a terminal device for storing programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and, of course, the extended storage medium supported by the terminal device. It can be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, device, or component. The computer-readable storage medium provides a storage space that stores the operating system of the terminal. And, in this storage space, one or more instructions suitable for being loaded and executed by the processor are also stored, and these instructions can be one or more computer programs (including program codes). It should be noted that more specific examples (non-exhaustive list) of the computer-readable storage medium here include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0097] The computer-readable storage medium also includes a data signal propagated in the baseband or as part of a carrier wave, which carries the readable program code. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The readable storage medium can also be any readable medium other than the readable storage medium, and this readable medium can send, propagate, or transmit a program for use by or in combination with an instruction execution system, device, or component. The program code contained on the readable storage medium can be transmitted by any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination of the above.

[0098] The program code for performing the operations of the present invention can be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, etc., and also including conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, executed as a stand-alone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user's computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., by connecting through the Internet using an Internet service provider).

[0099] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the energy storage-assisted thermal power unit frequency control method in the above embodiments; the one or more instructions in the computer-readable storage medium are loaded and executed by the processor to perform the following steps: Establish a cost model for the thermal power unit and energy storage combined system; establish an optimization objective function for the cost model of the thermal power unit and energy storage combined system with the optimal economy; consider the operating load of the thermal power unit, the load increase and decrease capacity, the margin required for energy storage-assisted frequency modulation, the state of charge of the energy storage system, and the maximum charge and discharge power of the energy storage system to establish the constraint conditions of the cost model of the thermal power unit and energy storage combined system; based on the cost model of the thermal power unit and energy storage combined system, the objective function, and the constraint conditions, establish an economic model for the combined operation of the thermal power unit and energy storage system, and improve the frequency modulation qualification rate of the thermal power unit by planning the charge and discharge power of the energy storage through the model to achieve deep peak shaving of the thermal power unit.

[0100] Please refer to Figure 6 , the terminal device is a computer device, and the computer device 60 of this embodiment includes: a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When the computer program 63 is executed by the processor 61, it implements the energy storage-assisted thermal power unit frequency control method in the embodiment. To avoid repetition, it will not be elaborated here one by one. Alternatively, when the computer program 63 is executed by the processor 61, it implements the functions of each model / unit in the energy storage-assisted thermal power unit frequency control system in the embodiment. To avoid repetition, it will not be elaborated here one by one.

[0101] The computer device 60 can be a computing device such as a desktop computer, a notebook, a palm computer, and a cloud server. The computer device 60 can include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art can understand, Figure 6This is only an example of the computer device 60 and does not limit the computer device 60. It may include more or fewer components than shown, or combine certain components, or have different components. For example, the computer device may also include input / output devices, network access devices, buses, etc.

[0102] The so-called processor 61 may be a central processing unit (CPU), or it may also be other general-purpose processors, central processors, graphics processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, data processing logic units based on quantum computing, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0103] The memory 62 may be an internal storage unit of the computer device 60, such as the hard disk or memory of the computer device 60. The memory 62 may also be an external storage device of the computer device 60, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the computer device 60.

[0104] Furthermore, the memory 62 may also include both the internal storage unit and the external storage device of the computer device 60. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 may also be used to temporarily store data that has been output or will be output.

[0105] In each of the embodiments provided in the present application, any reference to a memory, database, or other medium may include at least one of non-volatile and volatile memories. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0106] In each of the embodiments provided in the present application, the database involved may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., without limitation. In each of the embodiments provided in the present application, the processor involved may be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without limitation.

[0107] Please refer to Figure 7 , the terminal device 600 is an electronic device, and the electronic device is presented in the form of a general computing device. The components of the electronic device may include, but are not limited to: at least one processing unit 610, at least one storage unit 620, a bus 630 connecting different platform components (including the storage unit 620 and the processing unit 610), a display unit 640, etc.

[0108] Among them, the storage unit stores program code, and the program code can be executed by the processing unit 610, so that the processing unit 610 executes the steps according to various exemplary embodiments of the present invention described in the above method part of this specification. For example, the processing unit 610 can execute steps as shown in Figure 1 .

[0109] The storage unit 620 may include a readable medium in the form of a volatile storage unit, such as a random access storage unit (RAM) 6201 and / or a cache storage unit 6202, and may further include a read-only storage unit (ROM) 6203.

[0110] The storage unit 620 may also include a program / utilities 6204 having a set (at least one) of program modules 6205. Such program modules 6205 include, but are not limited to: an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment.

[0111] The bus 630 may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus structures.

[0112] The electronic device 600 may also communicate with one or more external devices 700 (such as a keyboard, a pointing device, a Bluetooth device, etc.), and may also communicate with one or more devices that enable a user to interact with the electronic device 600, and / or communicate with any device that enables the electronic device 600 to communicate with one or more other computing devices (such as a router, a modem, etc.). Such communication may be through an input / output (I / O) interface 650. Moreover, the electronic device 600 may also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter 660. The network adapter 660 may communicate with other modules of the electronic device 600 through the bus 630. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms, etc.

[0113] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the present invention described and shown in the accompanying drawings herein may be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0114] The frequency control method for energy storage-assisted thermal power units consists of the following three parts: 1. The device for statistically analyzing the frequency regulation and peak shaving requirements of energy storage-assisted thermal power units; Measure and collect the grid frequency at the grid connection node; collect and statistically analyze the automatic generation control commands issued by the grid dispatching side; and statistically analyze the average power of the frequency regulation tasks of the thermal power units over a period of time based on the historical data of the primary frequency regulation and secondary frequency regulation of the thermal power units.

[0115] 2. The device for monitoring the frequency regulation and operation status of thermal power units; Receive the power generation plan of the thermal power unit, the control signals issued by the control system of the thermal power unit, and the real-time operation information of the thermal power unit, and statistically analyze and predict the frequency regulation response capabilities of the thermal power unit at different load points.

[0116] 3. The device for controlling the frequency regulation and peak shaving of energy storage-assisted thermal power units.

[0117] Receive the average value of the frequency regulation task capacity of the thermal power unit over a period of time from the device for statistically analyzing the frequency regulation and peak shaving requirements of energy storage-assisted thermal power units, and the corresponding relationship between the power generation plan of the thermal power unit and the frequency regulation response capabilities of the thermal power unit at different load points output by the device for monitoring the frequency regulation and operation status of the thermal power unit. Calculate the daily energy storage output based on the above information and plan the state of charge of the energy storage.

[0118] The steps of the frequency control method for energy storage-assisted thermal power units are as follows: The first step: The device for statistically analyzing the frequency regulation and peak shaving requirements of energy storage-assisted thermal power units measures and collects the grid frequency data and the automatic generation control commands issued by the grid dispatching side. Statistically analyze the average power of the frequency regulation tasks of the thermal power unit over a period of time and update it periodically according to the data changes. The second step: The device for monitoring the frequency regulation and operation status of thermal power units receives the power generation plan of the thermal power unit, the control signals issued by the control system of the thermal power unit, and the real-time operation information of the thermal power unit, and statistically analyzes and predicts the frequency regulation response capabilities of the thermal power unit at different load points and updates it periodically according to the data changes.

[0119] The third step: Calculate the amount of electricity required for the energy storage to make up for the insufficient response of the thermal power unit according to the operation plan of the thermal power unit.

[0120] The fourth step: The device for controlling the frequency regulation and peak shaving of energy storage-assisted thermal power units receives the average frequency regulation power of the thermal power unit over a period of time from the device for statistically analyzing the frequency regulation and peak shaving requirements of energy storage-assisted thermal power units, and the power generation plan of the thermal power unit and the mapping relationship between the frequency regulation response capabilities of the thermal power unit at different load points output by the device for monitoring the frequency regulation and operation status of the thermal power unit. Calculate the daily energy storage output based on the above information and plan the state of charge of the energy storage.

[0121] Step 5: Send the planning result to the energy storage's own energy management system. The energy storage adjusts the daily state of charge according to the planning result, and the method for the energy storage to assist the thermal power unit in frequency control and deep peak shaving is completed.

[0122] Taking the plan of a certain power plant on a certain day as an example, compare the control effects and benefits.

[0123] Comparison of control effects

[0124] Statistically analyze the frequency modulation under different margin designs. Leaving a margin for primary and secondary frequency modulation within a day in the planning can effectively reduce the number of unqualified times. Moreover, as the margin increases, the number of unqualified times for frequency modulation gradually decreases. When a 10% margin is left, the frequency modulation requirements can be basically met. The average margin of the method in this paper is about 8.9%. On the premise that the frequency modulation effect is similar to that of 10%, the number of times of state of charge overlimit is further reduced, indicating that the control effect of the state of charge by the method in this paper is better than that of the 10% margin.

[0125] Benefit comparison

[0126] Taking no margin as the benchmark, compare the economic benefits under different margins. It can be seen that as the margin of the state of charge increases, the peak shaving benefit gradually decreases, which is caused by the reduction of the amount of electricity for the energy storage to assist the thermal power unit in peak shaving. However, correspondingly, a larger margin reduces the number of frequency modulation failures of the thermal power unit and improves the frequency modulation qualification rate of the thermal power unit, which greatly increases the frequency modulation benefit. Considering comprehensively, leaving a margin for the state of charge can reduce the cost of the thermal energy storage system, and the economy of the method of the present invention is better than that of other methods.

[0127] In summary, a method and system for an energy storage to assist a thermal power unit in frequency control according to the present invention, through the flexible charging and discharging of the energy storage, supplement the insufficient frequency modulation ability of the thermal power unit, and improve the frequency modulation qualification rate; at the same time, optimize the cooperation strategy between the energy storage and the thermal power, reduce the deep peak shaving time of the thermal power unit, and reduce the coal consumption and maintenance costs. Based on historical data and real-time adjustment planning, it can not only ensure the stability of the power grid frequency, but also reduce the overall operation cost by 10% - 20% by burning less coal and wearing less, and improve the benefits of thermal power enterprises.

[0128] Those skilled in the art can clearly understand that, for the convenience and conciseness of description, only the above-mentioned division of each functional unit and module is used as an example. In actual applications, the above-mentioned functions can be allocated to different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiments can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of each functional unit and module are only for the convenience of mutual distinction and do not limit the protection scope of this application. The specific working processes of the units and modules in the above system can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0129] In the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0130] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the present invention can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0131] In the embodiments provided by the present invention, it should be understood that the disclosed device / terminal and method can be implemented in other ways. For example, the device / terminal embodiments described above are only illustrative. For example, the division of the module or unit is only a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical, mechanical or other form.

[0132] The unit described as a separated component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it can be located in one place, or can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0133] In addition, in each embodiment of the present invention, each functional unit may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of a software functional unit.

[0134] If the above-mentioned integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a computer-readable storage medium. Based on such an understanding, to implement all or part of the processes in the above-mentioned embodiment methods of the present invention, it may also be completed by instructing relevant hardware through a computer program. The computer program may be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-mentioned various method embodiments may be implemented. Among them, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium may be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0135] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of this application. It should be understood that each process and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of processes and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate a device for implementing the specified functions in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0136] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured product including an instruction device, and the instruction device implements the process in Figure 1One process or multiple processes and / or blocks Figure 1 The functions specified in one block or multiple blocks.

[0137] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one process Figure 1 One process or multiple processes and / or blocks Figure 1 The steps of the functions specified in one block or multiple blocks.

[0138] The above content is only to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A frequency control method for a thermal power unit assisted by energy storage, characterized in that, It includes the following steps: Establish a cost model for a thermal power unit and energy storage combined system; Establish an optimization objective function for the cost model of the thermal power unit and energy storage combined system with the best economy; Considering the operating load of the thermal power unit, the load rising and falling capacity, the margin required for energy storage assisted frequency modulation, the state of charge of the energy storage system, and the maximum charge and discharge power of the energy storage system, establish the constraint conditions for the cost model of the thermal power unit and energy storage combined system; Based on the cost model of the thermal power unit and energy storage combined system, the objective function, and the constraint conditions, establish a combined operation economic model for the thermal power unit and energy storage system. By planning the charge and discharge power of the energy storage through the model, improve the qualified rate of frequency modulation of the thermal power unit and achieve deep peak shaving of the thermal power unit.

2. The frequency control method of the energy storage assisted thermal power unit according to claim 1, wherein Specifically, the construction of the cost model for the thermal power unit and energy storage combined system is as follows: Use the coal cost of the thermal power unit, the deep peak shaving cost of the thermal power unit, and the operation and use cost of the energy storage to construct the total system operation cost, and take minimizing the total system operation cost and the frequency modulation performance target as the objective function.

3. The frequency control method for a thermal power unit with energy storage assistance according to claim 1, characterized in that, The optimization objective function is: Among them, To maximize the frequency regulation economic benefits of the combined system of thermal power units and battery energy storage, is the operating income of the thermal power unit; is the operating income of the energy storage.

4. The frequency control method for a thermal power unit with energy storage assistance according to claim 3, wherein Operating revenue of thermal power units It is: Energy storage operation revenue It is as follows: Among them, is the power generation revenue of the thermal power unit, is the coal consumption cost of the thermal power unit / 10,000 yuan, is the additional cost required for oil injection during deep peak shaving of the thermal power unit, is the penalty cost for the thermal power unit failing to complete the power generation plan, is the energy storage operation cost, is the frequency regulation revenue.

5. The frequency control method for a thermal power unit with energy storage assistance according to claim 4, wherein The power generation revenue of thermal power units The coal consumption cost of thermal power units The additional cost required for oil injection during deep peak shaving of thermal power units The penalty cost for thermal power units failing to complete the power generation plan Are respectively: Among them, is the power generation revenue of the thermal power unit; is the planned power generation of the thermal power unit at time t; is the coal consumption cost of the thermal power unit; is the additional cost required for oil injection during deep peak shaving of the thermal power unit; is the penalty cost for the thermal power unit's failure to complete the power generation plan; is the coal consumption coefficient of the thermal power unit; The output of the thermal power unit at time t; is the oil injection volume of the thermal power unit at time t; is the current oil price; is the penalty coefficient for the failure to achieve the power generation plan.

6. The frequency control method for a thermal power unit with energy storage assistance according to claim 4, wherein Energy storage operation cost and frequency regulation revenue are respectively as follows: Among them, is the fixed operating cost of energy storage; is the charge and discharge power of energy storage; is the compensation for frequency regulation revenue; is the penalty for unqualified frequency regulation.

7. The frequency control method for a thermal power unit with energy storage assistance according to claim 1, characterized in that The constraint conditions for the cost model of the thermal power unit and energy storage combined system include: Power balance constraint: Among them, is the power generation plan of the thermal power unit, is the output of the thermal power unit, is the output of the energy storage system; Output power constraint of the thermal power unit: Among them, is the minimum output power of the thermal power unit / MW; is the maximum output power of the thermal power unit / MW; Ramp rate constraint of the thermal power unit: Among them, is the maximum ramp rate of the thermal power unit; Input power constraint of the energy storage system: Among them, is the minimum charge and discharge power of the energy storage system; is the maximum charge and discharge power of the energy storage system; State of charge constraint of the energy storage system: Among them, is the lower bound of the change in the state of charge of the current energy storage system, is the upper bound of the change in the state of charge of the current energy storage system.

8. The frequency control method for a thermal power unit with energy storage assistance according to claim 7, characterized in that, The calculation of the margin required for energy storage assisted frequency modulation is as follows: Analyze the historical data of primary frequency modulation and secondary frequency modulation of the thermal power unit, and count the power distribution of the frequency modulation tasks of the thermal power unit; analyze the frequency modulation ability of the thermal power unit under different loads; according to the operation plan of the thermal power unit, calculate the electricity required for the energy storage to make up for the insufficient response of the thermal power unit.

9. The frequency control method for a thermal power unit with energy storage assistance according to claim 7, characterized in that, Lower bound of the state of charge change of the current energy storage system and the upper bound of the state of charge change of the current energy storage system are respectively Among them, Frequency modulation margin in the discharging direction of the energy storage system, Frequency modulation margin in the charging direction of the energy storage system, is the state of charge of the energy storage at the current moment.

10. A frequency control system for a thermal power generating unit assisted by energy storage, characterized in that, It includes: A construction module to establish a cost model for a thermal power unit and energy storage combined system; A function module to establish an optimization objective function for the cost model of the thermal power unit and energy storage combined system with the best economy; A constraint module to establish the constraint conditions for the cost model of the thermal power unit and energy storage combined system considering the operating load of the thermal power unit, the load rising and falling capacity, the margin required for energy storage assisted frequency modulation, the state of charge of the energy storage system, and the maximum charge and discharge power of the energy storage system; A control module to establish a combined operation economic model for the thermal power unit and energy storage system based on the cost model of the thermal power unit and energy storage combined system, the objective function, and the constraint conditions. By planning the charge and discharge power of the energy storage through the model, improve the qualified rate of frequency modulation of the thermal power unit and achieve deep peak shaving of the thermal power unit.

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