Method, device and equipment for determining energy storage unit in hybrid energy storage system

Abstract

The present invention provides a method, device and equipment for determining an energy storage unit in a hybrid energy storage system, which can be applied to the technical field of power grid energy storage planning. The method includes: analyzing the target absorption power sequence associated with power fluctuation information of the energy storage system under target sampling parameters to obtain an amplitude sequence corresponding to the target absorption power sequence; determining the critical frequency according to the target sampling parameters; decomposing the amplitude sequence into a first amplitude subsequence and a second amplitude subsequence according to the critical frequency; processing the first amplitude subsequence and the second amplitude subsequence respectively according to the charge and discharge efficiency corresponding to the energy storage system to obtain the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence; generating first configuration parameters corresponding to the first target energy storage unit and second configuration parameters corresponding to the second target energy storage unit respectively according to the rated parameters.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid energy storage planning, and more specifically, to a method, device and equipment for determining an energy storage unit in a hybrid energy storage system. Background Art

[0002] With the large-scale grid connection of renewable energy, the intermittent and random nature of energy utilization has gradually become an obstacle to development. Therefore, energy storage systems can be introduced to absorb the random power fluctuations generated by the grid connection of renewable energy.

[0003] In the process of realizing the concept of the present invention, it was found through research that the energy storage system in the related art cannot effectively suppress the random power fluctuations caused by the grid connection of large-scale renewable energy according to the appropriate energy storage unit configuration, thereby making the stability of the grid operation low. Summary of the invention

[0004] In view of this, the present invention provides a method for determining an energy storage unit in a hybrid energy storage system.

[0005] One aspect of the present invention provides a method for determining an energy storage unit in a hybrid energy storage system, comprising: in response to receiving power fluctuation information generated by the energy storage system for processing renewable energy grid-connected operation, analyzing the target absorption power sequence associated with the power fluctuation information of the energy storage system under target sampling parameters to obtain an amplitude sequence corresponding to the target absorption power sequence; determining the critical frequency according to the target sampling parameters; decomposing the amplitude sequence into a first amplitude subsequence and a second amplitude subsequence according to the critical frequency; processing the first amplitude subsequence and the second amplitude subsequence respectively according to the charging and discharging efficiency corresponding to the energy storage system to obtain the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence; generating first configuration parameters corresponding to the first target energy storage unit and second configuration parameters corresponding to the second target energy storage unit respectively according to the rated parameters to determine the combination of target energy storage units; wherein the first target energy storage unit is used to store electric energy corresponding to the first amplitude subsequence, and the second target energy storage unit is used to store electric energy corresponding to the second amplitude subsequence.

[0006] According to an embodiment of the present invention, the target sampling parameters include a target volatility threshold, and the critical frequency is determined according to the target sampling parameters, including: formulating an initial critical frequency from a frequency sequence corresponding to the amplitude sequence; decomposing the amplitude sequence according to the initial critical frequency to obtain a first initial subsequence and a second initial subsequence, respectively; processing the first initial subsequence and the second initial subsequence, respectively, to obtain a first power volatility and a second power volatility corresponding to the initial critical frequency; adjusting the initial critical frequency according to the target volatility threshold until the first power volatility is greater than the target volatility threshold and the second power volatility is less than or equal to the target volatility threshold, and determining the current initial critical frequency as the critical frequency.

[0007] According to an embodiment of the present invention, a target absorption power sequence associated with power fluctuation information of an energy storage system under target sampling parameters is analyzed to obtain an amplitude sequence corresponding to the target absorption power sequence, including: obtaining a target sampling parameter according to the power fluctuation information; sampling according to the target sampling parameter to obtain a target absorption power sequence corresponding to the energy storage system; and performing Fourier transform on the target absorption power sequence to obtain an amplitude sequence corresponding to the target absorption power sequence.

[0008] According to an embodiment of the present invention, according to the charge and discharge efficiency corresponding to the energy storage system, the first amplitude subsequence and the second amplitude subsequence are processed respectively to obtain the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence, including: performing inverse Fourier transform on the first amplitude subsequence and the second amplitude subsequence respectively to obtain the first initial power subsequence corresponding to the first amplitude subsequence and the second initial power subsequence corresponding to the second amplitude subsequence; according to the charge and discharge efficiency, calibrating the first initial power subsequence and the second initial power subsequence respectively to obtain the first target power subsequence corresponding to the first initial power subsequence and the second target power subsequence corresponding to the second initial power subsequence; according to the first target power subsequence and the second target power subsequence, obtaining the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence.

[0009] According to an embodiment of the present invention, according to the charge and discharge efficiency, the first initial power subsequence and the second initial power subsequence are calibrated respectively to obtain a first target power subsequence corresponding to the first initial power subsequence and a second target power subsequence corresponding to the second initial power subsequence, including: according to the charge and discharge efficiency, respectively obtaining a first subsequence to be calibrated corresponding to the first initial power subsequence and a second subsequence to be calibrated corresponding to the second initial power subsequence; respectively formulating a first calibration power corresponding to the first subsequence to be calibrated and a second calibration power corresponding to the second subsequence to be calibrated, so that within the scheduling period, the charging amount of the first target energy storage unit and the second target energy storage unit is a predetermined charging threshold and the discharging amount is a predetermined discharging threshold; respectively updating the first calibration power and the second calibration power until both the first calibration power and the second calibration power are less than a predetermined accuracy threshold, respectively obtaining the first target power subsequence and the second target power subsequence according to the current first calibration power and the second calibration power.

[0010] According to an embodiment of the present invention, the rated parameters include rated capacity and rated power, the rated capacity includes a first rated capacity and a second rated capacity, and the rated power includes a first rated power and a second rated power; according to the first target power subsequence and the second target power subsequence, the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence are obtained respectively, including: in response to the maximum value in the first target power subsequence being less than the first rated power and the maximum value in the second target power subsequence being less than the second rated power, the first rated power is determined according to the maximum value in the first target power subsequence and the second rated power is determined according to the maximum value in the second target power subsequence; according to the first target power subsequence and the second target power subsequence, the first electric quantity change data corresponding to the first energy storage unit and the second electric quantity change data corresponding to the second energy storage unit are obtained respectively; according to the first electric quantity change data and the second electric quantity change data, the first rated capacity and the second rated capacity are obtained respectively.

[0011] According to an embodiment of the present invention, a first rated capacity and a second rated capacity are obtained respectively according to first power change data and second power change data, including: obtaining first state of charge data corresponding to the first energy storage unit and second state of charge data corresponding to the second energy storage unit respectively according to the first power change data and the second power change data; obtaining the first rated capacity according to the first state of charge data and the state of charge threshold of the first energy storage unit; and obtaining the second rated capacity according to the second state of charge data and the state of charge threshold of the second energy storage unit.

[0012] According to an embodiment of the present invention, first configuration parameters corresponding to the first target energy storage unit and second configuration parameters corresponding to the second target energy storage unit are respectively generated according to the rated parameters to determine a combination of target energy storage units, including: for candidate energy storage unit combinations consisting of different types of first energy storage units and second energy storage units in a candidate energy storage unit combination library, respectively establishing a functional relationship between the number of cycles of the candidate energy storage unit combination and the attenuation capacity of the energy storage system; and respectively generating first configuration parameters corresponding to the first target energy storage unit and second configuration parameters corresponding to the second target energy storage unit according to the functional relationship.

[0013] Another aspect of the present invention provides a device for determining an energy storage unit in a hybrid energy storage system, comprising: an analysis module, for analyzing a target absorption power sequence of the energy storage system associated with the power fluctuation information under target sampling parameters in response to receiving power fluctuation information generated when the energy storage system is used to process renewable energy when connected to the grid, to obtain an amplitude sequence corresponding to the target absorption power sequence; a determination module, for determining a critical frequency according to the target sampling parameters; a decomposition module, for decomposing the amplitude sequence into a first amplitude subsequence and a second amplitude subsequence according to the critical frequency; an acquisition module, for processing the first amplitude subsequence and the second amplitude subsequence respectively according to the charging and discharging efficiency corresponding to the energy storage system, to obtain the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence; a generation module, for generating first configuration parameters corresponding to the first target energy storage unit and second configuration parameters corresponding to the second target energy storage unit respectively according to the rated parameters, so as to determine a combination of target energy storage units.

[0014] Another aspect of the present invention provides an electronic device, comprising: one or more processors; and a memory for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method as described above.

[0015] According to an embodiment of the present invention, according to the target sampling parameters, the target absorbed power sequence under ideal conditions associated with the power fluctuation information generated when the energy storage system is connected to the grid with renewable energy is analyzed in the time domain to obtain an amplitude sequence, the amplitude sequence is decomposed according to the critical frequency, and the first rated parameter of the first amplitude subsequence and the second rated parameter of the second amplitude subsequence obtained by the decomposition are calculated according to the charging and discharging efficiency corresponding to the energy storage system, and the configuration parameters of the energy storage system are generated according to the rated parameters to confirm the optimal combination of energy storage units in the energy storage system. Since the power fluctuation information absorbed by each energy storage unit of the energy storage system is divided according to the frequency, while effectively suppressing the power fluctuation when the renewable energy is connected to the grid, it can release energy during the peak of power demand, reduce the dependence on traditional power generation resources, optimize the configuration of power resources by means of peak shaving and valley filling, and improve the absorption capacity of renewable energy. Therefore, it is conducive to improving the utilization efficiency of the energy storage system, maintaining the stability of the power grid operation, providing certain technical support for the configuration decision of the hybrid energy storage system, and providing theoretical and practical basis for the future development of the hybrid energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0017] Figure 1 A flow chart of a method for determining an energy storage unit in a hybrid energy storage system according to an embodiment of the present invention is shown.

[0018] Figure 2 A schematic diagram of an amplitude sequence according to an embodiment of the present invention is shown.

[0019] Figure 3 A schematic diagram showing actual output power of renewable energy according to an embodiment of the present invention is shown.

[0020] Figure 4 A flow chart for determining a critical frequency according to an embodiment of the present invention is shown.

[0021] Figure 5 A schematic diagram of a frequency sequence according to an embodiment of the present invention is shown.

[0022] Figure 6a A schematic diagram of a first power fluctuation rate sequence according to an embodiment of the present invention is shown.

[0023] Figure 6b A schematic diagram of a second power fluctuation rate sequence according to an embodiment of the present invention is shown.

[0024] Figure 7a A schematic diagram of a first target power subsequence according to an embodiment of the present invention is shown.

[0025] Figure 7b A schematic diagram of a second target power subsequence according to an embodiment of the present invention is shown.

[0026] Figure 8 A flowchart of calibrating a first initial power subsequence and a second initial power subsequence according to an embodiment of the present invention is shown.

[0027] Fig. 9 A schematic diagram showing changes in the state of charge of a target energy storage unit combination according to an embodiment of the present invention is shown.

[0028] Fig.10 A block diagram of a device for determining an energy storage unit in a hybrid energy storage system according to an embodiment of the present invention is shown.

[0029] Fig.11 A block diagram of an electronic device suitable for implementing a method for determining an energy storage unit in a hybrid energy storage system according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0030] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0031] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0032] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0033] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0034] In the embodiments of the present invention, the collection, updating, analysis, processing, use, transmission, provision, disclosure, storage and other aspects of the data involved (for example, including but not limited to user personal information) are in compliance with the provisions of relevant laws and regulations, are used for legitimate purposes, and do not violate public order and good morals. In particular, necessary measures are taken for user personal information to prevent illegal access to user personal information data and maintain the security of user personal information and network security.

[0035] In the embodiment of the present invention, before obtaining or collecting the user's personal information, the user's authorization or consent is obtained.

[0036] For using energy storage systems to meet the fluctuating demand for renewable energy consumption, using only a single type of energy storage system will cause the life of the system to decay quickly due to frequent charging and discharging, making it difficult to meet the technical requirements for smoothing grid-connected power fluctuations. If all the energy storage units in the energy storage system are replaced with types that can absorb high-frequency power to absorb grid-connected fluctuating power, it will be difficult to achieve a balance between performance and actual needs.

[0037] Based on this, a hybrid energy storage system consisting of two types of energy storage units, power and energy, can be used. It can not only effectively smooth out the instantaneous fluctuations of renewable energy fluctuation power, but also reduce dependence on traditional power generation resources by releasing energy during peak power demand periods, achieve peak shaving and valley filling, and optimize power resource allocation. The "peak shaving and valley filling" approach improves its absorption capacity. On this basis, there are many types of power and energy storage units, and each type of energy storage unit has its own technical characteristics. Different types of energy storage unit combinations have different utilization efficiencies.

[0038] In view of this, an embodiment of the present invention provides a method for determining an energy storage unit in a hybrid energy storage system, comprising: in response to receiving power fluctuation information generated by the energy storage system for processing renewable energy grid-connected operation, analyzing the target absorption power sequence associated with the power fluctuation information of the energy storage system under the target sampling parameters, and obtaining an amplitude sequence corresponding to the target absorption power sequence; determining the critical frequency according to the target sampling parameters; decomposing the amplitude sequence into a first amplitude subsequence and a second amplitude subsequence according to the critical frequency; processing the first amplitude subsequence and the second amplitude subsequence respectively according to the charging and discharging efficiency corresponding to the energy storage system, and obtaining the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence; generating first configuration parameters corresponding to the first target energy storage unit and second configuration parameters corresponding to the second target energy storage unit respectively according to the rated parameters to determine the combination of target energy storage units; wherein the first target energy storage unit is used to store electric energy corresponding to the first amplitude subsequence, and the second target energy storage unit is used to store electric energy corresponding to the second amplitude subsequence.

[0039] Figure 1 A flow chart of a method for determining an energy storage unit in a hybrid energy storage system according to an embodiment of the present invention is shown.

[0040] like Figure 1 As shown, the method includes operations S110 to S150.

[0041] In operation S110, in response to receiving power fluctuation information generated when the energy storage system is used to process renewable energy and is connected to the grid, a target absorption power sequence associated with the power fluctuation information of the energy storage system under target sampling parameters is analyzed to obtain an amplitude sequence corresponding to the target absorption power sequence.

[0042] According to an embodiment of the present invention, renewable energy such as wind energy and solar energy is intermittent and unpredictable, and will generate fluctuating power during grid-connected operation. The energy storage system can quickly respond to power fluctuations, absorb or release energy, and thus reduce power fluctuations.

[0043] According to an embodiment of the present invention, the target sampling parameters may include a power leveling period and a fluctuation rate threshold between adjacent sampling values.

[0044] According to an embodiment of the present invention, a target absorption power sequence can be obtained according to the requirements for absorbing fluctuations of renewable energy in different power smoothing time periods. The target absorption power sequence can represent the power sequence that the energy storage system can absorb under ideal conditions.

[0045] According to an embodiment of the present invention, analyzing the target absorption power sequence may be performing a time domain analysis of a Fourier transform on the target absorption power sequence to obtain an amplitude sequence corresponding to the target absorption power sequence, wherein the amplitude sequence represents an amplitude sequence of the fluctuating power corresponding to each sampling point.

[0046] Figure 2 A schematic diagram of an amplitude sequence according to an embodiment of the present invention is shown.

[0047] like Figure 2 As shown in the schematic diagram of the amplitude sequence, the horizontal axis is used to represent the sampling time t, in minutes (min); the vertical axis is used to represent the amplitude sequence X corresponding to the power of each sampling point HESS , the unit is kilowatt (Kw).

[0048] According to the embodiment of the present invention, it can be seen that the absorbed power of the energy storage system fluctuates violently at 0 kW. Therefore, using a single energy storage system to output this power may cause the energy storage system to charge and discharge frequently, thus reducing its life. Therefore, it is necessary to decompose the target absorbed power sequence of the energy storage system based on time-frequency analysis.

[0049] In operation S120, a critical frequency is determined according to a target sampling parameter.

[0050] According to an embodiment of the present invention, the critical frequency represents the critical point at which the power in the target absorption power sequence meets the fluctuation rate threshold, and the target absorption power sequence can be correspondingly divided into low-frequency fluctuation power and high-frequency fluctuation power.

[0051] According to an embodiment of the present invention, high-frequency fluctuating power can be processed using energy storage units with faster response speed and higher power density, such as lithium-ion batteries, flywheel energy storage, supercapacitors, etc., and low-frequency fluctuating power can be processed using energy storage units with higher energy density, such as: compressed air energy storage, lead-acid batteries, and hydrogen fuel cells.

[0052] In operation S130, the amplitude sequence is decomposed into a first amplitude subsequence and a second amplitude subsequence according to a critical frequency.

[0053] According to an embodiment of the present invention, the frequency of the first amplitude subsequence is greater than the critical frequency, and the frequency of the second amplitude subsequence is less than the critical frequency.

[0054] In operation S140, the first amplitude subsequence and the second amplitude subsequence are processed respectively according to the charge and discharge efficiency corresponding to the energy storage system to obtain the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence.

[0055] According to an embodiment of the present invention, the charging and discharging efficiency varies according to the type of energy storage unit selected, and can be obtained by searching in a candidate energy storage unit library. As shown in Table 1, the charging efficiency and discharging efficiency of several different energy storage units are listed.

[0056] Table 1

[0057]

[0058] According to an embodiment of the present invention, the target absorption power sequence does not consider the charging and discharging power, the first target energy storage unit is used to store the electric energy corresponding to the first amplitude subsequence, and the second target energy storage unit is used to store the electric energy corresponding to the second amplitude subsequence.

[0059] According to the embodiment of the present invention, the rated parameters can represent indicators for measuring the scale and energy storage capacity of the energy storage system, and play a decisive role in the performance of the energy storage system.

[0060] In operation S150 , first configuration parameters corresponding to the first target energy storage unit and second configuration parameters corresponding to the second target energy storage unit are respectively generated according to the rated parameters to determine a combination of target energy storage units.

[0061] According to an embodiment of the present invention, the configuration parameters reflect the cost and service life of the energy storage unit. Under the premise that the rated parameters are determined, the difference in configuration parameters determines the balance between the economy and technical performance of the energy storage system. Therefore, a combination of target energy storage units in which both the first configuration parameters and the second configuration parameters are optimal can be selected.

[0062] According to an embodiment of the present invention, according to the target sampling parameters, the target absorbed power sequence under ideal conditions associated with the power fluctuation information generated when the energy storage system is connected to the grid with renewable energy is analyzed in the time domain to obtain an amplitude sequence, the amplitude sequence is decomposed according to the critical frequency, and the first rated parameter of the first amplitude subsequence and the second rated parameter of the second amplitude subsequence obtained by the decomposition are calculated according to the charging and discharging efficiency corresponding to the energy storage system, and the configuration parameters of the energy storage system are generated according to the rated parameters to confirm the optimal combination of energy storage units in the energy storage system. Since the power fluctuation information absorbed by each energy storage unit of the energy storage system is divided according to the frequency, while effectively suppressing the power fluctuation when the renewable energy is connected to the grid, it can release energy during the peak of power demand, reduce the dependence on traditional power generation resources, optimize the configuration of power resources by means of peak shaving and valley filling, and improve the absorption capacity of renewable energy. Therefore, it is conducive to improving the utilization efficiency of the energy storage system, maintaining the stability of the power grid operation, providing certain technical support for the configuration decision of the hybrid energy storage system, and providing theoretical and practical basis for the future development of the hybrid energy storage system.

[0063] According to an embodiment of the present invention, a target absorption power sequence associated with power fluctuation information of an energy storage system under target sampling parameters is analyzed to obtain an amplitude sequence corresponding to the target absorption power sequence, including: obtaining a target sampling parameter according to the power fluctuation information; sampling according to the target sampling parameter to obtain a target absorption power sequence corresponding to the energy storage system; and performing Fourier transform on the target absorption power sequence to obtain an amplitude sequence corresponding to the target absorption power sequence.

[0064] According to an embodiment of the present invention, the power leveling time period and the fluctuation rate threshold between adjacent sampling values ​​in the target parameter can be queried from relevant technical regulations according to the power fluctuation information.

[0065] According to an embodiment of the present invention, the target absorbed power sequence P HESS It can be calculated according to the following formula (1).

[0066] (1)

[0067] Among them, P gc It can represent the combined output power of renewable energy and energy storage system, and the grid-connected power that can meet the target fluctuation rate threshold; P RE Represents the actual output power of renewable energy.

[0068] In order to better understand the power situation of the target absorption power sequence at each sampling point, the following will be Figure 3 , Taking the selection of a wind turbine with an installed capacity of 1.5 MW and a photovoltaic generator with an installed capacity of 1 MW, and a power leveling period of 1 min and a fluctuation rate threshold of 3% between adjacent sampling values ​​as an example, the actual output power of renewable energy is explained in detail.

[0069] Figure 3 A schematic diagram showing actual output power of renewable energy according to an embodiment of the present invention is shown.

[0070] like Figure 3 As shown, the schematic diagram of the actual output power of renewable energy shows the actual output power of renewable energy within 24 hours. Among the actual output powers corresponding to 1440 sampling moments, the maximum value is 1512.4 kilowatts and the minimum value is 0 kilowatts. The maximum value of the power fluctuation rate corresponding to adjacent sampling moments is 7.3%, which exceeds the fluctuation rate threshold of 3%.

[0071] According to an embodiment of the present invention, the target absorbed power sequence can be Fourier transformed to obtain the corresponding amplitude sequence X by the following formula (2): HESS .

[0072] (2)

[0073] Where DFT() stands for Discrete Fourier Transform, X HESS (n) represents the amplitude corresponding to the nth sampling, N sam Indicates the total number of sampling points.

[0074] According to an embodiment of the present invention, an initial critical frequency is formulated from a frequency sequence corresponding to the amplitude sequence; the amplitude sequence is decomposed according to the initial critical frequency to obtain a first initial subsequence and a second initial subsequence, respectively; the first initial subsequence and the second initial subsequence are processed respectively to obtain a first power volatility and a second power volatility corresponding to the initial critical frequency; according to a target volatility threshold, the initial critical frequency is adjusted until the first power volatility is greater than the target volatility threshold and the second power volatility is less than or equal to the target volatility threshold, and the current initial critical frequency is determined to be the critical frequency.

[0075] Figure 4 A flow chart for determining a critical frequency according to an embodiment of the present invention is shown.

[0076] like Figure 4 As shown, this embodiment includes operations S410 to S460.

[0077] In operation S410, an initial critical frequency is prepared from a frequency sequence corresponding to the amplitude sequence.

[0078] According to an embodiment of the present invention, the frequency sequence It can be obtained according to the following formula (3).

[0079] (3)

[0080] in, represents the sampling frequency, and in this embodiment, 1 time / minute is taken as an example, Indicates the frequency corresponding to the nth sampling.

[0081] According to an embodiment of the present invention, the initial critical frequency It can be calculated as 1.667×10 -2 Hz.

[0082] Figure 5 A schematic diagram of a frequency sequence according to an embodiment of the present invention is shown.

[0083] like Figure 5 As shown, in the schematic diagram of the frequency sequence, the number of sampling points is redistributed according to the frequency.

[0084] In operation S420, the amplitude sequence is decomposed according to the initial critical frequency to obtain a first initial subsequence and a second initial subsequence.

[0085] According to an embodiment of the present invention, the following formula (4) can be used to decompose the amplitude sequence into the values ​​related to the frequency according to the critical frequency: The first initial subsequence of the correlation and frequency The second initial subsequence .

[0086] (4)

[0087] According to an embodiment of the present invention, in the frequency band The corresponding amplitude just meets the limit of the renewable energy target volatility threshold and can be absorbed by the energy storage unit type with higher energy density; The corresponding amplitude does not meet the limit of the renewable energy target volatility threshold, and the high-frequency fluctuations are absorbed by energy storage types with faster response speed and higher power density to meet the grid connection requirements.

[0088] According to an embodiment of the present invention, the first initial subsequence The corresponding amplitude can be obtained according to the following formula (5).

[0089] (5)

[0090] According to an embodiment of the present invention, the second initial subsequence The corresponding amplitude can be obtained according to the following formula (6).

[0091] (6)

[0092] In operation S430, the first initial subsequence and the second initial subsequence are processed respectively to obtain a first power fluctuation rate and a second power fluctuation rate corresponding to the initial critical frequency.

[0093] According to an embodiment of the present invention, the following formula (7) is used to perform inverse Fourier transform processing on the first initial subsequence to obtain The corresponding first initial power subsequence P h (n).

[0094] (7)

[0095] Wherein, IDFT[ ] represents inverse Fourier transform.

[0096] According to an embodiment of the present invention, the second initial subsequence is subjected to inverse Fourier transform processing using the following formula (8) to obtain The corresponding second initial power subsequence P l (n).

[0097] (8)

[0098] According to an embodiment of the present invention, the first power fluctuation rate min (R h,1 ) can be obtained according to the following formula (9).

[0099] (9)

[0100] Among them, the first power fluctuation rate min (R h,1 ) is the minimum value of the power fluctuation between adjacent sampling points of the first initial power subsequence.

[0101] According to an embodiment of the present invention, the second power fluctuation rate max (R l,1 ) can be obtained according to the following formula (10).

[0102] (10)

[0103] Among them, the second power fluctuation rate max(R l,1 ) is the maximum value of the power fluctuation between adjacent sampling points of the second initial power subsequence.

[0104] In operation S440, it is determined whether the first power fluctuation rate is greater than the target fluctuation rate threshold and the second power fluctuation rate is less than or equal to the target fluctuation rate threshold. If the first power fluctuation rate is greater than the target fluctuation rate threshold and the second power fluctuation rate is less than or equal to the target fluctuation rate threshold, operation S460 is performed; otherwise, if the first power fluctuation rate is greater than the target fluctuation rate threshold and the second power fluctuation rate is less than or equal to the target fluctuation rate threshold is not satisfied, operation S450 is performed.

[0105] In operation S450, the initial critical frequency is adjusted.

[0106] According to an embodiment of the present invention, when the first power fluctuation rate is greater than the target volatility threshold and the second power fluctuation rate is less than or equal to the target volatility threshold is not satisfied, the initial critical frequency is gradually adjusted from low frequency to high frequency until the first power fluctuation rate is greater than the target volatility threshold and the second power fluctuation rate is less than or equal to the target volatility threshold.

[0107] According to the embodiment of the present invention, the amplitude sequence is decomposed again according to the adjusted initial critical frequency, and operations S310 to S340 are repeatedly performed.

[0108] In operation 460, the current initial critical frequency is determined to be the critical frequency.

[0109] According to an embodiment of the present invention, when f b =1.76×10 -3 Hz, min(R h,1 ) is greater than the target volatility threshold R pr,1 And max(R l,1 ) is less than R pr,1 , with R pr,1 =3% as an example, therefore, the critical frequency is 1.76×10 -3 Hz, the amplitude sequence can be divided into the first amplitude subsequence and the second amplitude subsequence according to this critical frequency.

[0110] Figure 6a A schematic diagram of a first power fluctuation rate sequence according to an embodiment of the present invention is shown.

[0111] like Figure 6a As shown, it can be obtained that the minimum value of the power fluctuation between adjacent sampling points of the first initial power subsequence is 3.03%.

[0112] Figure 6b A schematic diagram of a second power fluctuation rate sequence according to an embodiment of the present invention is shown.

[0113] like Figure 6bAs shown, it can be obtained that the maximum value of the power fluctuation between adjacent sampling points of the second initial power subsequence is 2.68%.

[0114] According to an embodiment of the present invention, through the above Figure 6a and Figure 6b In the embodiment, it can be verified that the initial critical frequency is 1.76×10 -3 Hz, it just meets the judgment criteria that the first power fluctuation rate is greater than the target fluctuation rate threshold and the second power fluctuation rate is less than or equal to the target fluctuation rate threshold. Therefore, the critical frequency is determined to be 1.76×10 -3 Hz.

[0115] According to an embodiment of the present invention, by determining the critical frequency, the amplitude sequence can be decomposed, thereby more reasonably allocating the energy storage units, so that the hybrid energy storage system can better smooth the intermittent output of renewable energy, improve the performance and efficiency of the overall energy storage system, and at the same time, enhance the stability and reliability of the power grid.

[0116] According to an embodiment of the present invention, according to the charge and discharge efficiency corresponding to the energy storage system, the first amplitude subsequence and the second amplitude subsequence are processed respectively to obtain the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence, including: performing inverse Fourier transform on the first amplitude subsequence and the second amplitude subsequence respectively to obtain the first initial power subsequence corresponding to the first amplitude subsequence and the second initial power subsequence corresponding to the second amplitude subsequence; according to the charge and discharge efficiency, calibrating the first initial power subsequence and the second initial power subsequence respectively to obtain the first target power subsequence corresponding to the first initial power subsequence and the second target power subsequence corresponding to the second initial power subsequence; according to the first target power subsequence and the second target power subsequence, obtaining the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence.

[0117] Figure 7a A schematic diagram of a first target power subsequence according to an embodiment of the present invention is shown.

[0118] like Figure 7a As shown, the horizontal axis represents time, and the vertical axis represents the power fluctuation of the first target power subsequence under time variation.

[0119] Figure 7b A schematic diagram of a second target power subsequence according to an embodiment of the present invention is shown.

[0120] like Figure 7bAs shown, the horizontal axis represents time, and the vertical axis represents the power fluctuation of the second target power subsequence under time variation.

[0121] By comparison, it can be seen that the image of the first target power subsequence schematic diagram obviously fluctuates more strongly over time than the image of the second target power subsequence schematic diagram.

[0122] According to an embodiment of the present invention, the amplitude sequence is divided into a first amplitude subsequence and a second amplitude subsequence according to the determined critical frequency. The first initial power subsequence and the second initial power subsequence can be obtained according to the above formulas (7) and (8), respectively, which will not be elaborated again.

[0123] According to an embodiment of the present invention, the rated parameters include rated capacity and rated power, the rated capacity includes a first rated capacity and a second rated capacity, and the rated power includes a first rated power and a second rated power. The rated power can represent the maximum electric power that the energy storage system can continuously output or absorb, in kilowatts (kW) or megawatts (MW); the rated capacity can represent the maximum amount of electricity that the energy storage system can store, usually in kilowatt-hours (kWh) or megawatt-hours (MWh).

[0124] According to an embodiment of the present invention, the first energy storage unit corresponds to a type with a faster response speed and a higher power density, and the second energy storage unit corresponds to a type with a higher energy density. The charging and discharging efficiency of each type of energy storage unit can be obtained from the candidate energy storage unit library, and the rated parameters of different type combinations can be obtained.

[0125] According to an embodiment of the present invention, according to the charge and discharge efficiency, the first initial power subsequence and the second initial power subsequence are calibrated respectively to obtain a first target power subsequence corresponding to the first initial power subsequence and a second target power subsequence corresponding to the second initial power subsequence, including: according to the charge and discharge efficiency, respectively obtaining a first subsequence to be calibrated corresponding to the first initial power subsequence and a second subsequence to be calibrated corresponding to the second initial power subsequence; respectively formulating a first calibration power corresponding to the first subsequence to be calibrated and a second calibration power corresponding to the second subsequence to be calibrated, so that within the scheduling period, the charging amount of the first target energy storage unit and the second target energy storage unit is a predetermined charging threshold and the discharging amount is a predetermined discharging threshold; respectively updating the first calibration power and the second calibration power until both the first calibration power and the second calibration power are less than a predetermined accuracy threshold, respectively obtaining the first target power subsequence and the second target power subsequence according to the current first calibration power and the second calibration power.

[0126] According to an embodiment of the present invention, the first subsequence P to be calibrated hdc (n) can be obtained according to the following formula (11).

[0127] (11)

[0128] Among them, η pd represents the discharge efficiency of the p-th energy storage unit, η pc Represents the discharge efficiency of the pth energy storage unit.

[0129] According to an embodiment of the present invention, the second subsequence P to be calibrated ldc (n) can be obtained according to the following formula (12).

[0130] (12)

[0131] According to an embodiment of the present invention, in actual operation, it is difficult for the energy storage system to ensure that the charge amount of the first target energy storage unit and the second target energy storage unit is a predetermined charge threshold and the discharge amount is a predetermined discharge threshold. In order to ensure that the charge amount of the first target energy storage unit and the second target energy storage unit is a predetermined charge threshold and the discharge amount is a predetermined discharge threshold within the scheduling cycle, it is necessary to calibrate the first subsequence to be calibrated and the second subsequence to be calibrated, and introduce the first calibration power and the second calibration power respectively. The charging threshold and the discharging threshold are both 0 so as not to affect the operation of the next scheduling cycle.

[0132] According to an embodiment of the present invention, the relationship between the charge and discharge amount of the first energy storage unit and the proposed first calibration power can be expressed as the following formula (13).

[0133] (13)

[0134] Among them, P hdc (n)+ΔP hdc represents the first target power subsequence after calibration that satisfies the net charge and discharge capacity of 0; E hdc Indicates the charge and discharge capacity of the first energy storage unit during the scheduling period; ΔP hdc is the first calibration power.

[0135] According to an embodiment of the present invention, the relationship between the charge and discharge amount of the second energy storage unit and the proposed second calibration power can be expressed as the following formula (14).

[0136] (14)

[0137] Among them, P ldc (n)+ΔP ldc represents the calibrated second target power subsequence that satisfies the net charge and discharge capacity of 0; E ldc Indicates the charge and discharge capacity of the second energy storage unit during the scheduling period; ΔP ldc is the second calibration power.

[0138] According to an embodiment of the present invention, the first calibration power and the second calibration power may be updated using a binary search method until both the first calibration power and the second calibration power are less than a predetermined accuracy threshold, thereby obtaining the determined first calibration power and the second calibration power. The first target power subsequence is obtained based on the sum of the first calibration power and the first power subsequence to be calibrated, and the second target power subsequence is obtained based on the sum of the second calibration power and the second power subsequence to be calibrated. The predetermined accuracy threshold may be 2.5 kW (i.e., 0.1%).

[0139] For example, the first calibration power and the second calibration power of different types of energy storage units are calculated as shown in Table 2 below.

[0140] Table 2

[0141]

[0142] Among them, lithium-ion batteries and supercapacitors are different types of the first energy storage unit, and lead-acid batteries and hydrogen fuel cells are different types of the second energy storage unit.

[0143] Figure 8 A flowchart of calibrating a first initial power subsequence and a second initial power subsequence according to an embodiment of the present invention is shown.

[0144] like Figure 8 As shown, this embodiment includes operations S810 to S850.

[0145] In operation S810, a first subsequence to be calibrated corresponding to the first initial power subsequence and a second subsequence to be calibrated corresponding to the second initial power subsequence are obtained according to the charge and discharge efficiency.

[0146] In operation S820, a first calibration power corresponding to the first subsequence to be calibrated and a second calibration power corresponding to the second subsequence to be calibrated are respectively prepared.

[0147] In operation S830, the first calibration power and the second calibration power are updated respectively.

[0148] In operation S840, it is determined whether the first calibration power and the second calibration power satisfy that the first calibration power and the second calibration power are both less than a predetermined precision threshold. If the first calibration power and the second calibration power are both less than the predetermined precision threshold, operation S850 is performed; otherwise, if the first calibration power and the second calibration power do not satisfy that the first calibration power and the second calibration power are both less than the predetermined precision threshold, the operation returns to operation S830.

[0149] In operation S850, a first target power subsequence and a second target power subsequence are obtained according to the current first calibration power and the second calibration power.

[0150] According to an embodiment of the present invention, by considering the charging and discharging efficiencies of different types of first energy storage units and second energy storage units, a first calibration power and a second calibration power are obtained, and a first target power subsequence and a second target power subsequence that can achieve periodic net energy of zero are obtained, thereby improving the operating efficiency and response speed of the energy storage system and ensuring efficient and reliable operation of the energy storage system.

[0151] According to an embodiment of the present invention, based on the first target power subsequence and the second target power subsequence, the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence are obtained respectively, including: in response to the maximum value in the first target power subsequence being less than the first rated power and the maximum value in the second target power subsequence being less than the second rated power, determining the first rated power according to the maximum value in the first target power subsequence and determining the second rated power according to the maximum value in the second target power subsequence; obtaining first electrical quantity change data corresponding to the first energy storage unit and second electrical quantity change data corresponding to the second energy storage unit according to the first target power subsequence and the second target power subsequence; obtaining the first rated capacity and the second rated capacity according to the first electrical quantity change data and the second electrical quantity change data.

[0152] According to an embodiment of the present invention, since the maximum absolute value of the power in the first target power subsequence must not exceed the first rated power, the first rated power P can be obtained according to the following formula (15): h,rated .

[0153] (15)

[0154] According to an embodiment of the present invention, since the maximum absolute value of the power in the second target power subsequence shall not exceed the second rated power, the second rated power P can be obtained according to the following formula (16): l,rated .

[0155] (16)

[0156] For example, the first rated power or the second rated power of different types of energy storage units may be as shown in Table 3 below.

[0157] Table 3

[0158]

[0159] According to an embodiment of the present invention, the first power change data corresponding to the first energy storage unit and the second power change data corresponding to the second energy storage unit both represent power change data between the current moment and the initial sampling moment.

[0160] According to an embodiment of the present invention, a first rated capacity and a second rated capacity are obtained respectively according to first power change data and second power change data, including: obtaining first state of charge data corresponding to the first energy storage unit and second state of charge data corresponding to the second energy storage unit respectively according to the first power change data and the second power change data; obtaining the first rated capacity according to the first state of charge data and the state of charge threshold of the first energy storage unit; and obtaining the second rated capacity according to the second state of charge data and the state of charge threshold of the second energy storage unit.

[0161] According to an embodiment of the present invention, the first state of charge data corresponding to the first energy storage unit can be calculated according to the following formula (17).

[0162] (17)

[0163] Among them, E h (n) represents the first state of charge data of the first energy storage unit at the nth sampling moment, E h (0) represents the first initial state of charge data of the first energy storage unit at the initial sampling time.

[0164] According to an embodiment of the present invention, according to an embodiment of the present invention, the second state of charge data corresponding to the second energy storage unit can be calculated according to the following formula (18).

[0165] (18)

[0166] Among them, E l (n) represents the second state of charge data of the second energy storage unit at the nth sampling time, E l (0) represents the second initial state of charge data of the second energy storage unit at the initial sampling time.

[0167] According to an embodiment of the present invention, the state of charge threshold is related to the material structure of the energy storage unit, and is used to reflect the state of charge range of the energy storage system under continuous stable and safe operation, including an upper limit and a lower limit. Different types of energy storage units correspond to different state of charge thresholds.

[0168] For example, the upper and lower limits of the state of charge thresholds of different types of energy storage units can be obtained by querying relevant data, as shown in Table 4 below.

[0169] Table 4

[0170]

[0171] According to an embodiment of the present invention, based on the upper and lower limits of the state of charge thresholds of different types of energy storage units and the first state of charge data, the first rated capacity can be obtained by the following formula (19).

[0172] (19)

[0173] in, It is used to indicate the maximum value of the first state of charge. Used to indicate the minimum value of the first state of charge, SOC max，p It is used to indicate the upper limit of the state of charge threshold of the p-th energy storage unit, SOC min，p Used to indicate the lower limit of the state of charge threshold of the p-th type of energy storage unit.

[0174] According to an embodiment of the present invention, based on the upper and lower limits of the state of charge thresholds of different types of energy storage units and the second state of charge data, the second rated capacity can be obtained by the following formula (20).

[0175] (20)

[0176] in, Used to indicate the maximum value of the second state of charge, The minimum value used to represent the second state of charge.

[0177] For example, the first rated capacity or the second rated capacity of different types of energy storage units is shown in Table 5 below.

[0178] Table 5

[0179]

[0180] According to an embodiment of the present invention, the first rated parameter of the first energy storage unit and the second rated parameter of the second energy storage unit are obtained by calculation, so as to ensure that the energy storage system operates within the limits of the rated parameters and avoid overload or damage to the energy storage system, which is a prerequisite for the subsequent calculation of configuration parameters to determine the target energy storage unit combination.

[0181] According to an embodiment of the present invention, first configuration parameters corresponding to the first target energy storage unit and second configuration parameters corresponding to the second target energy storage unit are respectively generated based on rated data to determine a combination of target energy storage units, including: for candidate energy storage unit combinations consisting of different types of first energy storage units and second energy storage units in a candidate energy storage unit combination library, respectively establishing a functional relationship between the number of cycles of the candidate energy storage unit combination and the attenuation capacity of the energy storage system; and based on the functional relationship, respectively generating first configuration parameters corresponding to the first target energy storage unit and second configuration parameters corresponding to the second target energy storage unit.

[0182] According to an embodiment of the present invention, since the rated capacity of some types of energy storage units will decay as the number of cycles increases, it is necessary to establish a functional relationship to obtain the remaining capacity of the energy storage unit after decay.

[0183] According to an embodiment of the present invention, the functional relationship between the number of cycles of the candidate energy storage unit combination and the attenuation capacity of the energy storage system includes the functional relationship between the number of cycles of the first energy storage unit and the first attenuation capacity and the functional relationship between the number of cycles of the second energy storage unit and the second attenuation capacity.

[0184] According to an embodiment of the present invention, the functional relationship between the number of cycles of use of the first energy storage unit and the first attenuation capacity can be expressed as the following formula (21).

[0185] (twenty one)

[0186] in, It represents the first attenuation capacity of the first energy storage unit after q-1 years of cycle use, N p represents the number of cycles used per year for the p-th energy storage unit, and d[ ] represents a function.

[0187] According to an embodiment of the present invention, the functional relationship between the number of cycles of use of the second energy storage unit and the second attenuation capacity can be expressed as the following formula (22).

[0188] (twenty two)

[0189] in, It represents the second attenuation capacity of the second energy storage unit after q-1 years of cyclic use.

[0190] For example, the remaining capacity percentage and cycle number of different types of energy storage units can be expressed as shown in Table 6 below.

[0191] Table 6

[0192]

[0193] According to an embodiment of the present invention, under the premise of determining the first rated capacity and the second rated capacity, different types of energy storage units have different technical characteristics, and their expected lifespans and expected benefits are different. Therefore, a functional relationship can be used to evaluate the balance between performance and cost of the candidate energy storage unit combination composed of different types of first energy storage units and second energy storage units in the candidate energy storage unit combination library, and the technical and economic advantages can be complemented to form the target energy storage unit combination with the highest "cost performance". Among them, the levelized cost can represent the ratio of the sum of the costs required within the life cycle to the charge and discharge power.

[0194] According to an embodiment of the present invention, energy storage unit types with faster response speed and higher power density (such as lithium-ion batteries, flywheel energy storage, supercapacitors, etc.) can be combined with energy storage unit types with higher energy density (such as compressed air energy storage, lead-acid batteries, hydrogen fuel cells), and the levelized costs of different candidate energy storage unit combinations are calculated respectively, and the candidate energy storage unit combination with the lowest levelized cost is obtained, which is the target energy storage unit combination.

[0195] According to an embodiment of the present invention, the first configuration parameter may represent the levelized cost of the first energy storage unit, and the second configuration parameter may represent the levelized cost of the second energy storage unit. The levelized cost of the candidate energy storage unit combination may be obtained according to the following formula (23).

[0196] (twenty three)

[0197] Among them, LC h represents the levelized cost of the first energy storage unit, LC l represents the levelized cost of the second energy storage unit; EIC h,p EIC represents the one-time cost investment for equipment purchase, installation, and decommissioning of the first energy storage unit of type p. l,p Represents the one-time cost investment for equipment purchase, installation, and decommissioning of the p-th type of second energy storage unit; OMC h,p represents the annual operation and maintenance cost of the first energy storage unit of type p, OMC l,p represents the annual operation and maintenance cost of the p-th type of second energy storage unit; REC h,p represents the annual replacement cost of the first energy storage unit of type p, REC l,p represents the annual replacement cost of the p-th type of second energy storage unit; r is the discount rate, which can be 8%; L h,p Indicates the life span of the first energy storage unit of the pth type, L l,p Indicates the life span of the p-th type of second energy storage unit; E h,q,p represents the decay capacity of the first energy storage unit of the pth type after the pth year, E l,q,p It represents the attenuation capacity of the p-th type second energy storage unit after the p-th year.

[0198] For example, the corresponding relationship between the service life of different types of energy storage units and the number of cycles per year is shown in Table 7 below.

[0199] Table 7

[0200]

[0201] According to an embodiment of the present invention, taking the above candidate energy storage units as an example, four candidate energy storage unit combinations can be obtained, and the types of combination 1 to combination 4 are as follows.

[0202] Combination 1: lithium-ion battery (first energy storage unit) + lead-acid battery (second energy storage unit); Combination 2: lithium-ion battery (first energy storage unit) + hydrogen fuel cell (second energy storage unit); Combination 3: supercapacitor (first energy storage unit) + lead-acid battery (second energy storage unit); Combination 4: supercapacitor (first energy storage unit) + hydrogen fuel cell (second energy storage unit).

[0203] According to an embodiment of the present invention, taking the above-mentioned combination 1 to combination 4 as an example, the levelized cost of each candidate energy storage unit combination can be obtained according to the following Table 8.

[0204] Table 8

[0205]

[0206] According to the embodiment of the present invention, by analyzing Table 7 and Table 8, hydrogen fuel cells have a better life and lower annual replacement cost than lead-acid batteries, but the one-time cost investment and annual operation and maintenance cost are much higher. At the same time, although supercapacitors have a higher one-time cost investment, due to their longer life and safer charge state threshold, the comprehensive use cost is still relatively low.

[0207] According to the embodiment of the present invention, a comprehensive comparison of the levelized costs of the above four combinations shows that the lowest levelized cost of combination 3: supercapacitor (first energy storage unit) + lead-acid battery (second energy storage unit) is 0.0885 yuan / kW·h. Therefore, combination 3 is the target energy storage unit combination.

[0208] According to an embodiment of the present invention, the configuration of the rated parameters and operating frequency bands of the target energy storage unit combination is shown in Table 9 below.

[0209] Table 9

[0210]

[0211] Fig. 9 A schematic diagram showing changes in the state of charge of a target energy storage unit combination according to an embodiment of the present invention is shown.

[0212] like Fig. 9 As shown, the change of the state of charge SOC over time first decreases and then increases.

[0213] According to an embodiment of the present invention, a target energy storage unit combination is determined from candidate energy storage units based on configuration parameters, and the technical characteristics of different energy storage units can be used to complement the service life and expected benefits under the constraints of technical and economic conditions, effectively meeting the fluctuating demand for renewable energy consumption from a technical perspective, while reducing costs as much as possible to maximize the utilization of the energy storage system.

[0214] Based on the above-mentioned method for determining an energy storage unit in a hybrid energy storage system, the present invention further provides a device for determining an energy storage unit in a hybrid energy storage system. Fig.10 The device is described in detail.

[0215] Fig.10 A block diagram of a device for determining an energy storage unit in a hybrid energy storage system according to an embodiment of the present invention is shown.

[0216] like Fig.10 As shown, the apparatus 1000 includes an analyzing module 1010 , a determining module 1020 , a decomposing module 1030 , an obtaining module 1040 and a generating module 1050 .

[0217] The analysis module 1010 is used to analyze the target absorption power sequence associated with the power fluctuation information of the energy storage system under the target sampling parameters in response to receiving the power fluctuation information generated when the energy storage system is used to process the power fluctuation information generated when the renewable energy is connected to the grid, and obtain the amplitude sequence corresponding to the target absorption power sequence.

[0218] The determination module 1020 is used to determine the critical frequency according to the target sampling parameter.

[0219] The decomposition module 1030 is used to decompose the amplitude sequence into a first amplitude subsequence and a second amplitude subsequence according to the critical frequency.

[0220] The obtaining module 1040 is used to process the first amplitude subsequence and the second amplitude subsequence respectively according to the charge and discharge efficiency corresponding to the energy storage system to obtain the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence.

[0221] The generating module 1050 is used to generate a first configuration parameter corresponding to the first target energy storage unit and a second configuration parameter corresponding to the second target energy storage unit according to the rated parameters, so as to determine a combination of target energy storage units.

[0222] According to an embodiment of the present invention, the determination module 1020 includes a formulation submodule, a decomposition submodule, a processing submodule and an adjustment submodule.

[0223] The proposed submodule is used to propose an initial critical frequency from a frequency sequence corresponding to the amplitude sequence.

[0224] The decomposition submodule is used to decompose the amplitude sequence according to the initial critical frequency to obtain a first initial subsequence and a second initial subsequence respectively.

[0225] The processing submodule is used to process the first initial subsequence and the second initial subsequence respectively to obtain a first power fluctuation rate and a second power fluctuation rate corresponding to the initial critical frequency.

[0226] The adjustment submodule is used to adjust the initial critical frequency according to the target volatility threshold until the first power volatility is greater than the target volatility threshold and the second power volatility is less than or equal to the target volatility threshold, and determine that the current initial critical frequency is the critical frequency.

[0227] According to an embodiment of the present invention, the analysis module 1010 includes an obtaining submodule, a sampling submodule and a transforming submodule.

[0228] The obtaining submodule is used to obtain target sampling parameters according to the power fluctuation information.

[0229] The sampling submodule is used to sample and obtain a target absorption power sequence corresponding to the energy storage system according to the target sampling parameters.

[0230] The transformation submodule is used to perform Fourier transformation on the target absorption power sequence to obtain an amplitude sequence corresponding to the target absorption power sequence.

[0231] According to an embodiment of the present invention, the obtaining module 1040 includes a first obtaining submodule, a calibration submodule and a second obtaining submodule.

[0232] The first obtaining submodule is used to perform inverse Fourier transform on the first amplitude subsequence and the second amplitude subsequence respectively to obtain a first initial power subsequence corresponding to the first amplitude subsequence and a second initial power subsequence corresponding to the second amplitude subsequence.

[0233] The calibration submodule is used to calibrate the first initial power subsequence and the second initial power subsequence according to the charge and discharge efficiency, and obtain a first target power subsequence corresponding to the first initial power subsequence and a second target power subsequence corresponding to the second initial power subsequence.

[0234] The second obtaining submodule is used to obtain the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence according to the first target power subsequence and the second target power subsequence.

[0235] According to an embodiment of the present invention, the calibration submodule includes an obtaining unit, a formulating unit and an updating unit.

[0236] The obtaining unit is used to obtain, according to the charge and discharge efficiency, a first subsequence to be calibrated corresponding to the first initial power subsequence and a second subsequence to be calibrated corresponding to the second initial power subsequence.

[0237] A planning unit is used to plan a first calibration power corresponding to the first subsequence to be calibrated and a second calibration power corresponding to the second subsequence to be calibrated, respectively, so that the charging amount of the first target energy storage unit and the second target energy storage unit is a predetermined charging threshold and the discharging amount is a predetermined discharging threshold during the scheduling period.

[0238] An updating unit is used to update the first calibration power and the second calibration power respectively until the first calibration power and the second calibration power are both less than a predetermined accuracy threshold, and then obtain a first target power subsequence and a second target power subsequence according to the current first calibration power and the second calibration power respectively.

[0239] According to an embodiment of the present invention, the second obtaining submodule includes a determining unit, a first obtaining unit and a second obtaining unit.

[0240] A determination unit is used to determine the first rated power according to the maximum value in the first target power subsequence and to determine the second rated power according to the maximum value in the second target power subsequence in response to the maximum value in the first target power subsequence being less than the first rated power and the maximum value in the second target power subsequence being less than the second rated power.

[0241] The first obtaining unit is used to obtain first power change data corresponding to the first energy storage unit and second power change data corresponding to the second energy storage unit according to the first target power subsequence and the second target power subsequence, respectively.

[0242] The second obtaining unit is used to obtain the first rated capacity and the second rated capacity according to the first power change data and the second power change data respectively.

[0243] According to an embodiment of the present invention, the second obtaining unit includes a first obtaining sub-unit, a second obtaining sub-unit and a third obtaining sub-unit.

[0244] The first obtaining subunit is used to obtain first state of charge data corresponding to the first energy storage unit and second state of charge data corresponding to the second energy storage unit according to the first power change data and the second power change data.

[0245] The second obtaining subunit is used to obtain the first rated capacity according to the first state of charge data and the state of charge threshold of the first energy storage unit.

[0246] The third obtaining subunit is used to obtain the second rated capacity according to the second state of charge data and the state of charge threshold of the second energy storage unit.

[0247] According to an embodiment of the present invention, the generation module 1050 includes a creation submodule and a generation submodule.

[0248] A submodule is established for establishing a functional relationship between the number of cycles of use of a candidate energy storage unit combination and the attenuation capacity of the energy storage system for each candidate energy storage unit combination consisting of different types of first energy storage units and second energy storage units in the candidate energy storage unit combination library.

[0249] The generating submodule is used to generate, according to the functional relationship, a first configuration parameter corresponding to the first target energy storage unit and a second configuration parameter corresponding to the second target energy storage unit.

[0250] According to the embodiments of the present invention, any one or more of the modules, submodules, units, and subunits, or at least part of the functions of any one of them can be implemented in one module. According to the embodiments of the present invention, any one or more of the modules, submodules, units, and subunits can be split into multiple modules for implementation. According to the embodiments of the present invention, any one or more of the modules, submodules, units, and subunits can be at least partially implemented as hardware circuits, such as field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), systems on chips, systems on substrates, systems on packages, application specific integrated circuits (ASICs), or can be implemented by hardware or firmware in any other reasonable way of integrating or packaging the circuit, or by any one of the three implementation methods of software, hardware, and firmware, or by a proper combination of any of them. Alternatively, according to the embodiments of the present invention, one or more of the modules, submodules, units, and subunits can be at least partially implemented as computer program modules, and when the computer program modules are run, the corresponding functions can be executed.

[0251] For example, any multiple of the analysis module 1010, the determination module 1020, the decomposition module 1030, the acquisition module 1040 and the generation module 1050 can be combined in one module / unit / sub-unit for implementation, or any one of the modules / units / sub-units can be split into multiple modules / units / sub-units. Alternatively, at least part of the functions of one or more of these modules / units / sub-units can be combined with at least part of the functions of other modules / units / sub-units and implemented in one module / unit / sub-unit. According to an embodiment of the present invention, at least one of the analysis module 1010, the determination module 1020, the decomposition module 1030, the acquisition module 1040 and the generation module 1050 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application specific integrated circuit (ASIC), or can be implemented by hardware or firmware such as any other reasonable way of integrating or packaging the circuit, or by any one of the three implementation methods of software, hardware and firmware or by a suitable combination of any of them. Alternatively, at least one of the analyzing module 1010 , the determining module 1020 , the decomposing module 1030 , the obtaining module 1040 , and the generating module 1050 may be at least partially implemented as a computer program module, and when the computer program module is executed, a corresponding function may be performed.

[0252] It should be noted that the device for determining the energy storage unit in the hybrid energy storage system in the embodiment of the present invention corresponds to the method for determining the energy storage unit in the hybrid energy storage system in the embodiment of the present invention. The description of the device for determining the method for the energy storage unit in the hybrid energy storage system specifically refers to the method for determining the energy storage unit in the hybrid energy storage system, which will not be repeated here.

[0253] Fig.11 A block diagram of an electronic device suitable for implementing a method for determining an energy storage unit in a hybrid energy storage system according to an embodiment of the present invention is shown.

[0254] Fig.11 The electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0255] like Fig.11As shown, the electronic device 1100 according to an embodiment of the present invention includes a processor 1101, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1102 or a program loaded from a storage part 1108 to a random access memory (RAM) 1103. The processor 1101 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or a related chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 1101 may also include an onboard memory for caching purposes. The processor 1101 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present invention.

[0256] In RAM 1103, various programs and data required for the operation of electronic device 1100 are stored. Processor 1101, ROM 1102 and RAM 1103 are connected to each other via bus 1104. Processor 1101 performs various operations of the method flow according to the embodiment of the present invention by executing the program in ROM 1102 and / or RAM 1103. It should be noted that the program can also be stored in one or more memories other than ROM 1102 and RAM 1103. Processor 1101 can also perform various operations of the method flow according to the embodiment of the present invention by executing the program stored in the one or more memories.

[0257] According to an embodiment of the present invention, the electronic device 1100 may further include an input / output (I / O) interface 1105, which is also connected to the bus 1104. The electronic device 1100 may further include one or more of the following components connected to the input / output (I / O) interface 1105: an input portion 1106 including a keyboard, a mouse, etc.; an output portion 1107 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage portion 1108 including a hard disk, etc.; and a communication portion 1109 including a network interface card such as a LAN card, a modem, etc. The communication portion 1109 performs communication processing via a network such as the Internet. A drive 1110 is also connected to the input / output (I / O) interface 1105 as needed. A removable medium 1111, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 1110 as needed, so that a computer program read therefrom is installed into the storage portion 1108 as needed.

[0258] According to an embodiment of the present invention, the method flow according to an embodiment of the present invention can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program carried on a computer-readable storage medium, and the computer program contains a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 1109, and / or installed from the removable medium 1111. When the computer program is executed by the processor 1101, the above-mentioned functions defined in the system of the embodiment of the present invention are executed. According to an embodiment of the present invention, the system, equipment, device, module, unit, etc. described above can be implemented by a computer program module.

[0259] The present invention also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiment; or may exist independently without being assembled into the device / apparatus / system. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiment of the present invention is implemented.

[0260] According to an embodiment of the present invention, the computer-readable storage medium may be a non-volatile computer-readable storage medium. For example, it may include but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, the computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, an apparatus or a device.

[0261] For example, according to an embodiment of the present invention, the computer-readable storage medium may include the ROM 1102 and / or the RAM 1103 described above and / or one or more memories other than the ROM 1102 and the RAM 1103 .

[0262] An embodiment of the present invention also includes a computer program product, which includes a computer program, which contains program code for executing the method provided by the embodiment of the present invention. When the computer program product is run on an electronic device, the program code is used to enable the electronic device to implement the method for determining the energy storage unit in the hybrid energy storage system provided by the embodiment of the present invention.

[0263] When the computer program is executed by the processor 1101, the above functions defined in the system / device of the embodiment of the present invention are executed. According to the embodiment of the present invention, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0264] In one embodiment, the computer program may rely on tangible storage media such as optical storage devices, magnetic storage devices, etc. In another embodiment, the computer program may also be transmitted and distributed in the form of signals on a network medium, and downloaded and installed through the communication part 1109, and / or installed from a removable medium 1111. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0265] According to an embodiment of the present invention, the program code for executing the computer program provided by the embodiment of the present invention can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level process and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, Java, C++, python, "C" language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on the remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user 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., using an Internet service provider to connect through the Internet).

[0266] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram may represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box may also occur in an order different from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions. It can be understood by those skilled in the art that the features recorded in the various embodiments of the present invention can be combined and / or combined in various ways, even if such a combination or combination is not explicitly recorded in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features recorded in the various embodiments of the present invention can be combined and / or combined in various ways. All these combinations and / or combinations fall within the scope of the present invention.

[0267] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although each embodiment is described above, it does not mean that the measures in each embodiment cannot be used in combination advantageously. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A method for determining an energy storage unit in a hybrid energy storage system, characterized in that: The method includes: In response to receiving power fluctuation information generated by an energy storage system for processing renewable energy when it is connected to the grid, analyzing a target absorption power sequence associated with the power fluctuation information under a target sampling parameter of the energy storage system to obtain an amplitude sequence corresponding to the target absorption power sequence, wherein the target sampling parameter includes a target fluctuation rate threshold; Determining a critical frequency according to the target sampling parameter includes: formulating an initial critical frequency from a frequency sequence corresponding to the amplitude sequence; Decomposing the amplitude sequence according to the initial critical frequency to obtain a first initial subsequence and a second initial subsequence respectively; Processing the first initial subsequence and the second initial subsequence respectively to obtain a first power fluctuation rate and a second power fluctuation rate corresponding to the initial critical frequency; According to the target fluctuation rate threshold, adjusting the initial critical frequency until the first power fluctuation rate is greater than the target fluctuation rate threshold and the second power fluctuation rate is less than or equal to the target fluctuation rate threshold, and determining that the current initial critical frequency is the critical frequency; Decomposing the amplitude sequence into a first amplitude subsequence and a second amplitude subsequence according to the critical frequency; According to the charge and discharge efficiency corresponding to the energy storage system, the first amplitude subsequence and the second amplitude subsequence are processed respectively to obtain the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence; Generating a first configuration parameter corresponding to the first target energy storage unit and a second configuration parameter corresponding to the second target energy storage unit respectively according to the rated parameters to determine a combination of the target energy storage units; The first target energy storage unit is used to store the electric energy corresponding to the first amplitude subsequence, and the second target energy storage unit is used to store the electric energy corresponding to the second amplitude subsequence.

2. The method according to claim 1, wherein: The step of analyzing the target absorbed power sequence associated with the power fluctuation information of the energy storage system under target sampling parameters to obtain an amplitude sequence corresponding to the target absorbed power sequence includes: Obtaining the target sampling parameter according to the power fluctuation information; According to the target sampling parameters, sampling is performed to obtain the target absorption power sequence corresponding to the energy storage system; Performing Fourier transform on the target absorption power sequence to obtain the amplitude sequence corresponding to the target absorption power sequence.

3. The method according to claim 1, wherein: The first amplitude subsequence and the second amplitude subsequence are processed respectively according to the charge and discharge efficiency corresponding to the energy storage system to obtain the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence, including: Performing inverse Fourier transform on the first amplitude subsequence and the second amplitude subsequence respectively to obtain a first initial power subsequence corresponding to the first amplitude subsequence and a second initial power subsequence corresponding to the second amplitude subsequence; According to the charge and discharge efficiency, calibrate the first initial power subsequence and the second initial power subsequence respectively to obtain a first target power subsequence corresponding to the first initial power subsequence and a second target power subsequence corresponding to the second initial power subsequence; According to the first target power subsequence and the second target power subsequence, the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence are obtained respectively.

4. The method according to claim 3, wherein: According to the charge and discharge efficiency, the first initial power subsequence and the second initial power subsequence are calibrated respectively to obtain a first target power subsequence corresponding to the first initial power subsequence and a second target power subsequence corresponding to the second initial power subsequence, including: According to the charge and discharge efficiency, respectively obtaining a first subsequence to be calibrated corresponding to the first initial power subsequence and a second subsequence to be calibrated corresponding to the second initial power subsequence; respectively formulate a first calibration power corresponding to the first subsequence to be calibrated and a second calibration power corresponding to the second subsequence to be calibrated, so that within a scheduling period, the charge amount of the first target energy storage unit and the second target energy storage unit is a predetermined charge threshold and the discharge amount is a predetermined discharge threshold; The first calibration power and the second calibration power are updated respectively until the first calibration power and the second calibration power are both less than a predetermined accuracy threshold, and the first target power subsequence and the second target power subsequence are obtained according to the current first calibration power and the second calibration power respectively.

5. The method according to claim 3, wherein: The rated parameters include a rated capacity and a rated power, the rated capacity includes a first rated capacity and a second rated capacity, and the rated power includes a first rated power and a second rated power; the step of obtaining, according to the first target power subsequence and the second target power subsequence, the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence, respectively, includes: In response to a maximum value in the first target power subsequence being less than the first rated power and a maximum value in the second target power subsequence being less than the second rated power, determining the first rated power according to the maximum value in the first target power subsequence and determining the second rated power according to the maximum value in the second target power subsequence; According to the first target power subsequence and the second target power subsequence, first power change data corresponding to the first target energy storage unit and second power change data corresponding to the second target energy storage unit are obtained respectively; The first rated capacity and the second rated capacity are obtained respectively according to the first electric quantity change data and the second electric quantity change data.

6. The method according to claim 5, wherein: The obtaining the first rated capacity and the second rated capacity according to the first power change data and the second power change data respectively includes: According to the first power change data and the second power change data, respectively obtaining first state of charge data corresponding to the first target energy storage unit and second state of charge data corresponding to the second target energy storage unit; Obtaining the first rated capacity according to the first state of charge data and the state of charge threshold of the first target energy storage unit; and The second rated capacity is obtained according to the second state of charge data and a state of charge threshold of the second target energy storage unit.

7. The method according to claim 1, wherein: The generating, according to the rated parameters, first configuration parameters corresponding to the first target energy storage unit and second configuration parameters corresponding to the second target energy storage unit to determine the combination of the target energy storage units includes: For candidate energy storage unit combinations consisting of different types of the first target energy storage units and the second target energy storage units in the candidate energy storage unit combination library, a functional relationship between the number of cycles of the candidate energy storage unit combinations and the attenuation capacity of the energy storage system is established respectively; According to the functional relationship, a first configuration parameter corresponding to the first target energy storage unit and a second configuration parameter corresponding to the second target energy storage unit are generated respectively.

8. A configuration device for a hybrid energy storage system, comprising: an analysis module, configured to analyze a target absorption power sequence associated with the power fluctuation information of the energy storage system under a target sampling parameter in response to receiving power fluctuation information generated when the energy storage system is used to process the power fluctuation information during grid-connected operation of renewable energy, and obtain an amplitude sequence corresponding to the target absorption power sequence, wherein the target sampling parameter includes a target fluctuation rate threshold; The determination module is used to determine the critical frequency according to the target sampling parameter, including: formulating an initial critical frequency from a frequency sequence corresponding to the amplitude sequence; decomposing the amplitude sequence according to the initial critical frequency to obtain a first initial subsequence and a second initial subsequence respectively; processing the first initial subsequence and the second initial subsequence respectively to obtain a first power fluctuation rate and a second power fluctuation rate corresponding to the initial critical frequency; adjusting the initial critical frequency according to the target fluctuation rate threshold until the first power fluctuation rate is greater than the target fluctuation rate threshold and the second power fluctuation rate is less than or equal to the target fluctuation rate threshold, and determining that the current initial critical frequency is the critical frequency; A decomposition module, used for decomposing the amplitude sequence into a first amplitude subsequence and a second amplitude subsequence according to the critical frequency; an obtaining module, configured to process the first amplitude subsequence and the second amplitude subsequence respectively according to the charge and discharge efficiency corresponding to the energy storage system, to obtain the rated parameters of the first target energy storage unit corresponding to the first amplitude subsequence and the rated parameters of the second target energy storage unit corresponding to the second amplitude subsequence; A generating module is used to generate a first configuration parameter corresponding to the first target energy storage unit and a second configuration parameter corresponding to the second target energy storage unit according to the rated parameters, so as to determine a combination of the target energy storage units.

9. An electronic device, comprising: one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors execute the method according to any one of claims 1 to 7.

Images