Energy storage device control method and device, storage medium and energy storage device

Abstract

The application discloses an energy storage device control method and device, a storage medium and an energy storage device. The method comprises the following steps: acquiring power information, and determining a plurality of electricity price time periods of a working day of the energy storage device according to the power information; generating a preliminary charging and discharging strategy according to the plurality of electricity price time periods; wherein the preliminary charging and discharging strategy comprises: configuring the energy storage device in a discharging mode in a high electricity price time period, and configuring the energy storage device in a charging mode in a low electricity price time period; determining a charging and discharging switching frequency based on the preliminary charging and discharging strategy, determining a target charging and discharging strategy of the energy storage device based on the charging and discharging switching frequency and the time length of the plurality of electricity price time periods, and determining the charging and discharging state of the energy storage device in each electricity price time period. The method provided in the application can improve the utilization rate of energy storage resources, take into account the battery life of the energy storage device, and improve the energy storage arbitrage income.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, specifically to an energy storage device control method, apparatus, storage medium, and energy storage device. Background Technology

[0002] Peak-valley electricity pricing, also known as time-of-use pricing, is an electricity pricing system that calculates electricity costs separately for peak and off-peak consumption. Peak consumption generally refers to electricity usage during peak hours when power supply is tight, such as during the daytime, and the charges are higher. Off-peak consumption generally refers to electricity usage during off-peak hours when power supply is more abundant, such as at night, and the charges are lower. Implementing peak-valley pricing encourages electricity users to stagger their electricity consumption times, making full use of equipment and energy.

[0003] Currently, industrial and commercial energy storage applications on the user side are booming. Power generation companies can charge energy storage devices during off-peak hours and provide electricity through energy storage devices during peak hours to make a profit. However, in the current power trading center, electricity prices are updated in real time. Currently, energy storage devices are controlled according to preset charging and discharging strategies, which leads to the waste of energy storage resources. Furthermore, frequent switching of the charging and discharging states of energy storage devices can also affect battery life. Summary of the Invention

[0004] In view of the above problems, this application provides a method, apparatus, storage medium and energy storage device for controlling energy storage devices, which can improve the utilization rate of energy storage resources of user-side energy storage devices and extend the service life of batteries.

[0005] Firstly, this application provides a control method for an energy storage device, which can be applied to an energy storage device. The method may include:

[0006] The system acquires electricity information and determines multiple electricity price periods for the energy storage device on a workday based on the electricity information; wherein the electricity information includes historical electricity price trends, and the electricity price periods include high electricity price periods and low electricity price periods.

[0007] A preliminary charge / discharge strategy is generated based on the multiple electricity price periods; wherein, the preliminary charge / discharge strategy includes: configuring the energy storage device in discharge mode during the high electricity price period and in charging mode during the low electricity price period.

[0008] The charging and discharging switching frequency is determined based on the preliminary charging and discharging strategy. The target charging and discharging strategy of the energy storage device is determined based on the charging and discharging switching frequency and the duration of the multiple electricity price periods. The charging and discharging status of the energy storage device in each electricity price period is determined.

[0009] In the technical solution of this application embodiment, the initial charging and discharging strategy of the energy storage device during working days can be predicted by historical power information, and the initial charging and discharging strategy can be optimized based on the duration of each electricity price period, thereby reducing the charging and discharging switching frequency of the energy storage device. This can improve the utilization rate of energy storage resources while taking into account the battery life of the energy storage device and increasing the arbitrage income of energy storage.

[0010] In some embodiments, the electricity information further includes preset electricity price information;

[0011] The determination of multiple electricity price periods based on the electricity information includes:

[0012] Based on the historical peak-valley electricity price information or the preset electricity price information, predict the time periods of each high-electricity-price period and each low-electricity-price period during the weekday for the energy storage device.

[0013] In addition to peak-valley energy storage arbitrage, the technical solution of this application embodiment can also be applied to auxiliary frequency regulation of isolated grids. By obtaining the electricity price information of the electricity-consuming enterprises, the load changes of the electricity-consuming enterprises on the working days of the energy storage equipment can be predicted, thereby controlling the charging and discharging status of the energy storage equipment and improving the flexibility of energy storage resource utilization.

[0014] In some embodiments, determining the target charging and discharging strategy of the energy storage device based on the charging and discharging switching frequency and the duration of the plurality of electricity price periods may include:

[0015] When the charging / discharging switching frequency is greater than a preset switching frequency threshold, the energy storage device is controlled to maintain the same charging or discharging state as the adjacent time period during the target electricity price period; wherein, the target electricity price period is an electricity price period with a duration shorter than a preset duration threshold.

[0016] In the technical solution of this application embodiment, the initial charging and discharging strategy can be optimized by predicting the duration of each high electricity price period and each low electricity price period, thereby reducing the charging and discharging switching frequency of the energy storage device and extending the service life of the battery in the energy storage device.

[0017] In some embodiments, the high electricity price period may include peak and low-price periods, and the low electricity price period may include flat and low-price periods.

[0018] Determining the charging and discharging status of the energy storage device during each electricity price period includes:

[0019] The energy storage device is configured to discharge at maximum output power during peak hours, discharge at a rated power of (N-N1) / h2 during high-peak hours, charge at a rated power of N / h3 during low-peak hours, and charge at a rated power of N / h4 during flat-peak hours.

[0020] Wherein, N is the total energy storage of the energy storage device, N1 is the output energy of the energy storage device during the peak period of the energy storage device on the working day, h2 is the duration of the peak period of the energy storage device on the working day, h3 is the duration of the valley period of the energy storage device on the working day, and h4 is the duration of the flat period of the energy storage device on the working day.

[0021] In the technical solution of this application embodiment, the charging and discharging state of the energy storage device can be controlled by the generated target charging and discharging strategy, which can make full use of the energy storage resources of the energy storage device, improve the utilization rate of energy storage resources, and thus increase the energy storage arbitrage income.

[0022] In some embodiments, determining the charge / discharge state of the energy storage device during each electricity price period may further include:

[0023] During the off-peak and normal periods, the energy storage device is charged, and when the energy storage capacity of the energy storage device is detected to be greater than the preset energy storage capacity, the charging of the energy storage device is restricted or stopped.

[0024] In the technical solution of this application embodiment, the impact of overcharging on the battery health of the energy storage device can be taken into account during the energy storage arbitrage process. When the energy storage capacity of the energy storage device reaches a preset value, the charging of the energy storage device is restricted or stopped to prevent overcharging that may occur in each charging cycle, thereby further ensuring battery health and extending battery life.

[0025] In some embodiments, the method provided in this application may further include:

[0026] During the working days of the energy storage device, the power demand for the current period and the next period is predicted based on the power forecasting model. Based on the power demand and the target charging and discharging strategy, it is determined whether to switch the charging and discharging state of the energy storage device in the next period.

[0027] In the technical solution of this application embodiment, the target charging and discharging strategy can be adjusted in real time according to the actual situation of the energy storage device in the energy storage arbitrage process, which can improve the stability of the energy storage device, make full use of energy storage resources, and ensure battery health.

[0028] In some embodiments, when the energy storage device is in the charging state of the charge / discharge state, it is charged at the lowest charging rate.

[0029] In the technical solution of this application embodiment, by controlling the charging of the energy storage device at the lowest charging rate, the charging stability of the energy storage device can be improved, thereby extending the battery life.

[0030] Secondly, this application provides an energy storage arbitrage device, applied to energy storage equipment, comprising:

[0031] The acquisition module is used to acquire power information and determine multiple electricity price periods for the energy storage device on a working day based on the power information; wherein, the power information includes historical electricity price trends, and the electricity price periods include high electricity price periods and low electricity price periods.

[0032] The first strategy determination module is used to generate a preliminary charge and discharge strategy based on the multiple electricity price periods; wherein the preliminary charge and discharge strategy includes: the energy storage device is configured to discharge mode during the high electricity price period and to charge mode during the low electricity price period.

[0033] The second strategy determination module is used to determine the charge-discharge switching frequency based on the preliminary charge-discharge strategy, determine the target charge-discharge strategy of the energy storage device based on the charge-discharge switching frequency and the duration of the multiple electricity price periods, and determine the charge-discharge state of the energy storage device in each electricity price period.

[0034] In some embodiments, the acquisition module may be specifically used for:

[0035] Based on historical peak and valley electricity price information or preset electricity price information, predict the time periods during which the energy storage equipment will be located during each weekday period with high electricity price and each period with low electricity price.

[0036] In some embodiments, the second strategy determination module may be specifically used for:

[0037] When the charging and discharging switching frequency is greater than the preset switching frequency threshold, the energy storage device is controlled to maintain the same charging or discharging state as the adjacent period of the target electricity price period during the target electricity price period; wherein, the target electricity price period is the electricity price period with a duration less than the preset duration threshold.

[0038] In some embodiments, high electricity price periods may include peak periods and high-peak periods, and low electricity price periods may include flat periods and low-peak periods;

[0039] The second strategy determination module can also be used for:

[0040] The energy storage device is configured to discharge at maximum output power during peak hours, discharge at a rated power of (N-N1) / h2 during high-peak hours, charge at a rated power of N / h3 during low-peak hours, and charge at a rated power of N / h4 during flat-peak hours.

[0041] Where N is the total energy storage capacity of the energy storage device, N1 is the output energy of the energy storage device during the peak period of the energy storage device's working day, h2 is the duration of the peak period of the energy storage device's working day, h3 is the duration of the valley period of the energy storage device's working day, and h4 is the duration of the flat period of the energy storage device's working day.

[0042] In some embodiments, the second strategy determination module can also be used for:

[0043] During off-peak and normal periods, the energy storage device is charged, and if the energy storage capacity of the energy storage device is detected to be greater than the preset energy storage capacity, the charging of the energy storage device is restricted or stopped.

[0044] In some embodiments, the energy storage arbitrage device may include a control module for predicting the electricity demand for the current period and the next period based on a power forecasting model during the working day of the energy storage device, and determining whether to switch the charging and discharging state of the energy storage device in the next period according to the electricity demand and the target charging and discharging strategy.

[0045] In some embodiments, the second strategy determination module can also be used for:

[0046] When the energy storage device is in the charging state of charging and discharging, it is charged at the lowest charging rate.

[0047] Thirdly, this application provides a computer-readable storage medium storing computer program instructions, which, when executed by a processor, perform the steps in the above-described method.

[0048] Fourthly, this application provides an energy storage device, which includes a battery, a memory, and a processor. The battery is used to store electrical energy, the memory stores program instructions, and when the processor runs the program instructions, it performs the steps in the above method.

[0049] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0050] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0051] Figure 1 This is a schematic diagram of peak-valley electricity pricing in a certain area;

[0052] Figure 2 Schematic diagrams illustrating the steps of an energy storage device control method provided in some embodiments of this application;

[0053] Figure 3 A flowchart illustrating energy storage arbitrage provided in this application embodiment;

[0054] Figure 4 A schematic diagram of an energy storage arbitrage device provided in an embodiment of this application. Detailed Implementation

[0055] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0057] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0058] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0059] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0060] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0061] Currently, judging from the development of the market situation, the peak-valley electricity pricing system can fully leverage the economic role of prices, alleviate the contradiction between electricity supply and demand, improve the grid load rate and equipment utilization rate, control peak load, utilize off-peak electricity, tap the potential of power generation and supply equipment, and thus improve economic efficiency.

[0062] The inventors have noted that in electricity spot market transactions, power generation companies provide electricity price quotes, and large users or electricity sales companies provide their required electricity quantities. These transactions are conducted through electricity trading centers or integrated energy service companies. However, during the trading process at the electricity trading center, electricity prices fluctuate in real time. Therefore, the power supply method of energy storage devices cannot be the same as that of users using peak-valley electricity, charging during fixed off-peak hours and discharging during fixed peak hours. Specifically, see [link to relevant documentation]. Figure 1 , Figure 1 This is a schematic diagram of peak-valley electricity pricing in a certain area. Figure 1 It can be seen that the electricity price in this area fluctuates throughout the day, with the highest daily price reaching 1.4 yuan per kilowatt-hour and the lowest price being only 0.2 yuan per kilowatt-hour. Therefore, by formulating a reasonable charging and discharging strategy, energy storage devices can be controlled to charge during periods of low electricity price and discharge during periods of high electricity price, thereby utilizing energy storage resources and realizing peak-valley electricity price arbitrage.

[0063] To improve the profitability of energy storage arbitrage, the applicant's research found that it's possible to predict electricity prices for different time periods on a given weekday, thereby developing a charging and discharging strategy for the energy storage device. This involves charging during predicted off-peak hours and discharging during predicted peak hours. However, considering battery lifespan, excessively frequent switching between charging and discharging states can severely impact battery life. Therefore, it's not feasible to simply control the energy storage device to switch to charging during predicted off-peak hours and discharging during predicted peak hours.

[0064] Based on the above considerations, in order to balance the energy storage revenue and battery life of energy storage devices, the inventors have conducted in-depth research and proposed an energy storage arbitrage method. By formulating the charging and discharging strategy of the energy storage device based on the predicted electricity price period on the working day, the charging and discharging strategy is optimized to reduce the frequency of charging and discharging switching, thereby balancing the resource utilization rate of the energy storage device and the battery life.

[0065] The energy storage arbitrage method disclosed in this application can be applied to energy storage devices, which can specifically be battery systems. Energy storage arbitrage primarily involves utilizing the daily peak-valley electricity price difference to charge the energy storage device during periods of low electricity prices and then using the device to provide power during periods of high electricity prices. This can involve transmitting the power to electricity-consuming enterprises or supplying power to power centers, thereby generating profit based on the price difference.

[0066] Please refer to Figure 2 , Figure 2 This is a schematic diagram illustrating the steps of an energy storage device control method provided in some embodiments of this application. The energy storage device control method may include the following steps:

[0067] In step S21, power information is acquired, and multiple electricity price periods for the energy storage device on weekdays are determined based on the power information.

[0068] The method in this application embodiment can be implemented using intelligent software. The intelligent control software can be deployed on an Energy Management System (EMS), which can obtain power information from power trading centers and integrated energy service companies.

[0069] The electricity information may include historical electricity price trends. These trends could be the electricity price trend on the day before the energy storage device's operating day, the electricity price trend on the same day in previous years, the average electricity price trend over multiple days, or the electricity price trend under similar scenarios in the past, such as severe weather like typhoons, droughts, or significant temperature drops or rises. The operating day of the energy storage device can be the date on which the energy storage device is determined to operate, the day after the application of the solution provided in this application, or any day in the future when the solution provided in this application is applied. Electricity price periods may include high electricity price periods and low electricity price periods. In this embodiment, electricity prices higher than a preset value are used as high electricity prices, and electricity prices lower than a preset value are used as low electricity prices.

[0070] It should be understood that the high and low electricity prices in the embodiments of this application are merely illustrative and can be set according to specific market conditions in actual application, and should not be construed as a limitation on the scope of protection of this application.

[0071] In step S22, a preliminary charging and discharging strategy is generated based on multiple electricity price periods.

[0072] The initial charge / discharge strategy may include configuring the energy storage device to discharge mode during periods of high electricity price and to charge mode during periods of low electricity price. Specifically, in step S22, there is no limit to the number of electricity price periods generated; each period with an electricity price higher than a preset value can be designated as a high electricity price period, and each period with an electricity price lower than a preset value can be designated as a low electricity price period, so that the generated initial charge / discharge strategy can be optimized in step S23.

[0073] For example, the steps of generating a preliminary charging and discharging strategy may include: inputting the daily electricity price trend of the previous day in the electricity market or a preset input electricity price trend, determining the high electricity price period and the low electricity price period respectively, determining to control the energy storage device to discharge during the high electricity price period and to charge during the low electricity price period.

[0074] In step S23, the charging and discharging switching frequency is determined based on the preliminary charging and discharging strategy. The target charging and discharging strategy of the energy storage device is determined based on the charging and discharging switching frequency and the duration of multiple electricity price periods. The charging and discharging status of the energy storage device in each electricity price period is determined.

[0075] For example, the implementation method of determining the charging and discharging switching frequency based on the preliminary charging and discharging strategy may include: representing the electricity price trend with a broken line, determining the charging and discharging frequency by the number of intersections between the electricity price broken line and the preset electricity price; if the charging and discharging switching frequency is lower than or equal to the preset switching frequency value, the above step S23 can be omitted, and the preliminary charging and discharging strategy can be directly used as the final charging and discharging strategy; if the charging and discharging switching frequency is higher than the preset switching frequency value, it is determined that the above step S23 needs to be executed to optimize the preliminary charging and discharging strategy, thereby reducing the charging and discharging switching frequency of the energy storage device and extending the battery life.

[0076] One strategy for optimizing the initial charge / discharge process is to first preset a time period duration threshold. Then, merge high-price and low-price periods below this threshold into the previous or next time period. Determine if the merged charge / discharge switching frequency is lower than or equal to a preset switching frequency value. If so, the merged strategy can be used as the final strategy. If not, another preset time period threshold can be set for the next round of merging to keep the switching frequency within the preset range. Another strategy is to ignore high-price and low-price periods below the preset time period threshold, maintaining the same charge / discharge state as the previous period during these periods. Alternatively, during high-price periods below the preset time period threshold, the energy storage device can be kept off, neither charging nor discharging, allowing it to charge only during low-price periods and discharge during high-price periods above the preset time period threshold. Alternatively, an optimized initial charging and discharging strategy could be to merge multiple consecutive time periods below a preset duration threshold, determine the average electricity price within the merged time period, and then determine whether the energy storage device is in a charging or discharging state based on the average electricity price within that merged time period.

[0077] Therefore, the embodiments of this application can predict the initial charging and discharging strategy of the energy storage device during working days based on historical power information, and optimize the initial charging and discharging strategy based on the duration of each electricity price period, thereby reducing the charging and discharging switching frequency of the energy storage device. This can improve the utilization rate of energy storage resources while taking into account the battery life of the energy storage device and increasing the arbitrage income of energy storage.

[0078] Optionally, according to some embodiments of this application, the power information in the solution may also include preset electricity price information. For step S21, determining multiple electricity price periods based on the power information may include predicting the time periods of each high-price and low-price period during the workday of the energy storage device based on daily historical peak-valley electricity price information or preset electricity price information.

[0079] For example, in addition to being applied to peak-valley arbitrage via energy storage devices on the user side, the embodiments of this application can also be applied to auxiliary frequency regulation of isolated grids. An isolated grid refers to a local power grid operating independently from the main power grid, specifically a grid where the maximum capacity of a single isolated unit is greater than 8% of the total grid capacity. Large-scale electricity consumers, such as metal smelting companies, can directly form isolated grid loops with power plants, thereby saving on electricity costs. However, isolated grid systems suffer from poor stability because isolated grid operation shifts from load control to frequency control. During isolated grid operation, frequency fluctuations can occur when generating units experience varying degrees of load impact. These fluctuations may lead to frequency collapse, and in severe cases, even power outages, resulting in economic losses and production disruptions. Therefore, during isolated grid operation, it is necessary to automatically maintain grid frequency stability under varying user load conditions. Thus, the method provided in the embodiments of this application can be used to predict user electricity load and control the power supply of the energy storage system based on the prediction results, keeping the isolated grid frequency near the rated frequency, thereby preventing the impact of frequency fluctuations caused by load impacts on enterprises.

[0080] Specifically, the prediction method can be to read preset electricity price information, which can be historical electricity consumption data provided by the electricity user or the electricity consumption plan of the energy storage device on working days. Based on the historical electricity consumption data of the electricity user, the power consumption of the electricity user on the working days of the energy storage device can be predicted, thereby determining when to charge the energy storage device, when to discharge it, and the discharge power in each time period.

[0081] Therefore, the embodiments of this application can be applied not only to peak-valley energy storage arbitrage, but also to auxiliary frequency regulation of isolated grids. By obtaining the electricity price information of electricity users, the load changes of electricity users on the working days of energy storage equipment can be predicted, thereby controlling the charging and discharging status of energy storage equipment and improving the flexibility of energy storage resource utilization.

[0082] Optionally, for step S23, this application embodiment provides an implementation method for optimizing the initial charging and discharging strategy based on the electricity price period. This implementation method can control the energy storage device to maintain the same charging or discharging state as the adjacent period of the target electricity price period when the charging and discharging switching frequency is greater than a preset switching frequency threshold.

[0083] The target electricity price period refers to the electricity price period whose duration is less than a preset duration threshold. The charging / discharging switching frequency can be set according to the actual electricity consumption situation. In this embodiment, the charging / discharging switching frequency of the energy storage device can be set to no more than 4 times. If the switching frequency exceeds 4 times, it can be determined that the initial charging / discharging strategy needs to be optimized. The preset duration threshold can be set according to the actual electricity consumption situation, such as 15 minutes, 30 minutes, 60 minutes, or 120 minutes.

[0084] In addition, the methods for determining high-price and low-price periods can be to make the period precise to every minute, or to divide the high-price and low-price periods into 15 minutes, 30 minutes, 60 minutes or 120 minutes respectively. When the average electricity price for a fixed duration is higher or lower than the preset electricity price, the period can be determined as a high-price or low-price period.

[0085] Taking a target electricity price period accurate to every minute and a preset duration threshold of 15 minutes as an example, when the detected charging / discharging switching frequency is higher than 4 times, periods with a duration of less than 15 minutes in each determined electricity price period can be merged into adjacent periods. The merging into the previous or next period can be determined based on the durations of the previous and next periods. If the charging / discharging switching frequency of the energy storage device is less than or equal to 4 times after the first merging, the charging / discharging strategy after the merged period can be used as the target charging / discharging strategy. If the number of charging / discharging switching times of the energy storage device is still higher than 4 times after the first merging, the preset duration threshold can be changed to 30 minutes and merging can be performed again, in the same way as the first merging process. If the number of charging / discharging switching times is higher than 4 times after the merged period, the preset duration threshold can be changed to a larger value until the charging / discharging switching frequency is less than or equal to 4 times, at which point the target charging / discharging strategy is generated.

[0086] Therefore, the embodiments of this application can optimize the initial charge and discharge strategy by predicting the duration of each high electricity price period and each low electricity price period, thereby reducing the charge and discharge switching frequency of the energy storage device and extending the service life of the battery in the energy storage device.

[0087] According to some embodiments of this application, optionally, the high-electricity-price period and the low-electricity-price period can be further divided. The high-electricity-price period can be divided into peak periods and high-peak periods, and the low-electricity-price period can be divided into flat periods and low-peak periods. The method for determining the charging and discharging state of the energy storage device in step S23 for each electricity-price period may include:

[0088] The energy storage device is configured to discharge at maximum output power during peak hours, discharge at rated power of (N-N1) / h2 during peak hours, charge at rated power of N / h3 during off-peak hours, and charge at rated power of N / h4 during flat hours. Here, N is the total energy stored by the energy storage device, N1 is the output energy of the energy storage device during peak hours on a workday, h2 is the duration of peak hours on a workday, h3 is the duration of off-peak hours on a workday, and h4 is the duration of flat hours on a workday.

[0089] For example, in actual implementation, the electricity price can be divided into four stages based on four specific electricity values. For instance, the period with an electricity price higher than 1.1 yuan can be designated as the peak period, with a total duration of h1; the period with an electricity price between 0.6 and 1.1 yuan can be designated as the mid-peak period, with a total duration of h2; the period with an electricity price below 0.2 yuan can be designated as the off-peak period, with a total duration of h3; and the period with an electricity price between 0.2 and 0.6 yuan can be designated as the neutral period, with a total duration of h4. It should be understood that the above electricity values ​​are merely illustrative and can be set according to actual circumstances when implementing the scheme provided in this application, and should not be construed as a limitation on the scope of protection of this application.

[0090] The method of controlling energy storage devices based on target charging and discharging strategies can be to control the energy storage devices to discharge with the maximum output current Imax during peak periods in order to maximize profits, and to discharge with the rated power of (N-N1) / h2 during peak periods in order to make full use of the energy storage resources of the energy storage devices.

[0091] In addition, when charging energy storage devices during peak and off-peak hours, a charging method that limits the charging current can be used to prevent the energy storage device from overheating during charging and affecting battery life.

[0092] Therefore, the embodiments of this application can control the charging and discharging state of the energy storage device through the generated target charging and discharging strategy, which can make full use of the energy storage resources of the energy storage device, improve the utilization rate of energy storage resources, and thus increase the energy storage arbitrage income.

[0093] Optionally, according to some embodiments of this application, the method of controlling the charging state of the energy storage device during low electricity price periods in step S23 of the embodiments of this application may include:

[0094] During off-peak and normal periods, the energy storage device is charged, and if the energy storage capacity of the energy storage device is detected to be greater than the preset energy storage capacity, the charging of the energy storage device is restricted or stopped.

[0095] During the research process, the applicant noticed that, in addition to the high frequency of switching between charge and discharge states of energy storage devices affecting the lifespan of the energy storage device batteries, overcharging and over-discharging in each charging cycle will cause permanent damage to the positive and negative electrodes of lithium-ion batteries. From a molecular level, over-discharging will cause excessive release of lithium ions from the negative electrode carbon, resulting in the collapse of its layered structure. Overcharging will force too many lithium ions into the negative electrode carbon structure, making some of them unable to be released, thus leading to a shortened battery lifespan.

[0096] Therefore, in terms of design, a low-current stepped charging method can be used to charge the energy storage device. By setting a preset energy storage capacity and monitoring the current energy storage capacity of the device in real time, charging can be stopped or a smaller current can be used when the current energy storage capacity of the device reaches the preset value. Specifically, the preset energy storage capacity can be set to 90%, 80%, etc., of the total energy storage capacity of the device, or it can be set according to the actual situation or the current battery health of the device.

[0097] Therefore, the embodiments of this application can take into account the impact of overcharging on the battery health of the energy storage device during the energy storage arbitrage process. When the energy storage capacity of the energy storage device reaches a preset value, the charging of the energy storage device is restricted or stopped to prevent overcharging that may occur in each charging cycle, thereby further ensuring battery health and extending battery life.

[0098] Optionally, according to some embodiments of this application, the energy storage arbitrage method provided in the embodiments of this application can also adjust the working status of the energy storage device according to the actual situation during the arbitrage process. Specific adjustment methods may include:

[0099] During the working days of energy storage equipment, the power demand for the current period and the next period is predicted based on the power forecasting model. Based on the power demand and the target charging and discharging strategy, it is determined whether to switch the charging and discharging state of the energy storage equipment in the next period.

[0100] Specifically, energy storage devices and power conversion systems (PCS) can communicate with the energy storage system (EMS) via fiber optic cables to respond in real time to the EMS's charge / discharge switching control commands. During energy storage arbitrage, the EMS can calculate the current and next time period's electricity demand and price using a power forecasting model on a cloud server. By combining the forecast results with the target charge / discharge strategy, when the predicted electricity demand is high and the electricity price is high, the EMS determines whether the target charge / discharge strategy should control the energy storage device to be in a discharging state. If so, the energy storage device's state can be maintained; otherwise, it can be switched to a discharging state. Furthermore, the weight values ​​for electricity demand, electricity price, time period duration, and the target charge / discharge strategy can be set separately, and the weight values ​​of each parameter can be comprehensively calculated to control the charge / discharge state of the energy storage device.

[0101] Therefore, the embodiments of this application can adjust the target charging and discharging strategy in real time according to the actual situation of the energy storage device in the energy storage arbitrage process, which can improve the stability of the energy storage device, make full use of energy storage resources, and ensure battery health.

[0102] In an optional embodiment, when the energy storage device is in a charging state during charging and discharging, it can also be controlled to charge the energy storage device at the lowest charging rate.

[0103] Among them, the charging rate is a measure of the charging speed. It refers to the current value required for a battery to be charged to its rated capacity within a specified time. Numerically, it is equal to the ratio of the charging current to the battery's rated capacity.

[0104] By controlling the charging of energy storage devices to the lowest possible charging rate, the stability of charging can be improved, thereby extending battery life.

[0105] According to some embodiments of this application, see Figure 3 , Figure 3 The energy storage arbitrage flowchart provided in this application embodiment shows that the process of controlling the energy storage device when performing energy storage arbitrage on the same day can be as follows:

[0106] To maximize profit, the energy storage device is controlled to discharge at the maximum output current Imax for h1 during the predicted peak period. During the peak period, it discharges at the rated power of (N-N1) / h2 for h2 to fully utilize the energy storage resources. During the off-peak period, it charges at the charging power of N / h3 for h3, and during the flat period, it charges at the charging power of N / h4 for h4. After allocating the duration of each period and the corresponding charging and discharging power of the energy storage device, it is calculated whether the daily energy storage arbitrage and charging and discharging switching frequency meet the requirements. If yes, the energy storage device can be controlled based on the generated target charging and discharging strategy. If no, the generated charging and discharging strategy can be further optimized by reducing the charging and discharging frequency, and the daily arbitrage profit can be recalculated. The duration of each period and the charging and discharging power can also be redistributed.

[0107] Based on the same inventive concept, this application also provides an energy storage arbitrage device 40, please refer to... Figure 4 , Figure 4 This is a schematic diagram of an energy storage arbitrage device provided in an embodiment of this application. The energy storage arbitrage device 40 may include:

[0108] The acquisition module 41 is used to acquire power information and determine multiple electricity price periods for the energy storage device on weekdays based on the power information; wherein, the power information includes historical electricity price trends, and the electricity price periods include high electricity price periods and low electricity price periods.

[0109] The first strategy determination module 42 is used to generate a preliminary charging and discharging strategy based on multiple electricity price periods; wherein, the preliminary charging and discharging strategy includes: the energy storage device is configured to discharge mode during high electricity price periods and to charge mode during low electricity price periods.

[0110] The second strategy determination module 43 is used to determine the charging and discharging switching frequency based on the preliminary charging and discharging strategy, determine the target charging and discharging strategy of the energy storage device based on the charging and discharging switching frequency and the duration of multiple electricity price periods, and determine the charging and discharging status of the energy storage device in each electricity price period.

[0111] By predicting the initial charge and discharge strategies of energy storage devices during working days based on historical power information, and optimizing the initial charge and discharge strategies based on the duration of each electricity price period, the frequency of charge and discharge switching of energy storage devices is reduced. This allows for both improved energy storage resource utilization and battery life of energy storage devices, thereby increasing energy storage arbitrage profits.

[0112] Optionally, the acquisition module 41 may be specifically used for:

[0113] Based on historical peak and valley electricity price information or preset electricity price information, predict the time periods during which the energy storage equipment will be located during each weekday period with high electricity price and each period with low electricity price.

[0114] Therefore, in addition to peak-valley energy storage arbitrage, this application can also be applied to auxiliary frequency regulation of isolated grids. By obtaining the electricity price information of electricity users, the load changes of electricity users on the working days of energy storage equipment can be predicted, thereby controlling the charging and discharging status of energy storage equipment and improving the flexibility of energy storage resource utilization.

[0115] Optionally, the second strategy determination module 43 may be specifically used for:

[0116] When the charging and discharging switching frequency is greater than the preset switching frequency threshold, the energy storage device is controlled to maintain the same charging or discharging state as the adjacent period of the target electricity price period during the target electricity price period; wherein, the target electricity price period is the electricity price period with a duration less than the preset duration threshold.

[0117] By optimizing the initial charge / discharge strategy based on the predicted duration of each high-electricity-price period and each low-electricity-price period, the frequency of charge / discharge switching of energy storage devices can be reduced, and the lifespan of batteries in energy storage devices can be extended.

[0118] Optionally, high electricity price periods may include peak and off-peak periods, and low electricity price periods may include flat and off-peak periods;

[0119] The second strategy determination module 43 can also be used for:

[0120] The energy storage device is configured to discharge at maximum output power during peak hours, discharge at rated power of (N-N1) / h2 during peak hours, charge at rated power of N / h3 during off-peak hours, and charge at rated power of N / h4 during flat hours.

[0121] Where N is the total energy storage capacity of the energy storage device, N1 is the output energy of the energy storage device during the peak period of the energy storage device's working day, h2 is the duration of the peak period of the energy storage device's working day, h3 is the duration of the valley period of the energy storage device's working day, and h4 is the duration of the flat period of the energy storage device's working day.

[0122] Therefore, the embodiments of this application can control the charging and discharging state of the energy storage device through the generated target charging and discharging strategy, which can make full use of the energy storage resources of the energy storage device, improve the utilization rate of energy storage resources, and thus increase the energy storage arbitrage income.

[0123] Optionally, the second strategy determination module 43 can also be used for:

[0124] During off-peak and normal periods, the energy storage device is charged, and if the energy storage capacity of the energy storage device is detected to be greater than the preset energy storage capacity, the charging of the energy storage device is restricted or stopped.

[0125] Therefore, the embodiments of this application can take into account the impact of overcharging on the battery health of the energy storage device during the energy storage arbitrage process. When the energy storage capacity of the energy storage device reaches a preset value, the charging of the energy storage device is restricted or stopped to prevent overcharging that may occur in each charging cycle, thereby further ensuring battery health and extending battery life.

[0126] Optionally, the energy storage arbitrage device 40 may include a control module for predicting the electricity demand for the current period and the next period based on the power forecasting model during the working day of the energy storage device, and determining whether to switch the charging and discharging state of the energy storage device in the next period according to the electricity demand and the target charging and discharging strategy.

[0127] Therefore, the embodiments of this application can adjust the target charging and discharging strategy in real time according to the actual situation of the energy storage device in the energy storage arbitrage process, which can improve the stability of the energy storage device, make full use of energy storage resources, and ensure battery health.

[0128] Optionally, the second strategy determination module 43 can also be used for:

[0129] When the energy storage device is in the charging state of charging and discharging, it is charged at the lowest charging rate.

[0130] By controlling the charging of energy storage devices to the lowest possible charging rate, the stability of charging can be improved, thereby extending battery life.

[0131] Based on the same inventive concept, embodiments of this application also provide a computer-readable storage medium storing computer program instructions, which, when read and executed by a processor, perform the steps in any of the above implementations.

[0132] Computer-readable storage media can be various media capable of storing program code, such as Random Access Memory (RAM), Read Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), and Electrically Erasable Programmable Read-Only Memory (EEPROM). The storage medium stores the program, and the processor executes the program after receiving execution instructions. Furthermore, the method executed by the electronic terminal defined by the process disclosed in any embodiment of this application can be applied to a processor or implemented by the processor.

[0133] Based on the same concept, this application also provides an energy storage device, which may include a battery, a memory, and a processor. The battery is used to store electrical energy, the memory stores program instructions, and the processor executes the steps in the above method when running the program instructions.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A control method for an energy storage device, characterized in that, The method includes: The system acquires electricity information and determines multiple electricity price periods for the energy storage device on a workday based on the electricity information; wherein the electricity information includes historical electricity price trends, and the electricity price periods include high electricity price periods and low electricity price periods; A preliminary charging and discharging strategy is generated based on the multiple electricity price periods; wherein, the preliminary charging and discharging strategy includes: the energy storage device is configured to discharge mode during the high electricity price period and to charge mode during the low electricity price period; Based on the preliminary charging and discharging strategy, a charging and discharging switching frequency is determined. Based on the charging and discharging switching frequency and the duration of the multiple electricity price periods, a target charging and discharging strategy for the energy storage device is determined. The charging and discharging state of the energy storage device in each electricity price period is determined, including: when the charging and discharging switching frequency is greater than a preset switching frequency threshold, controlling the energy storage device to maintain the same charging or discharging state as the adjacent period during the target electricity price period; wherein, the target electricity price period is an electricity price period with a duration less than a preset duration threshold; or, controlling the energy storage device to be in a closed state during high electricity price periods with a duration less than the preset duration threshold; or, merging multiple consecutive time periods with a duration less than the preset duration threshold, determining the average electricity price in the merged time period, and determining whether the energy storage device is in a charging or discharging state during the merged time period based on the average electricity price.

2. The method according to claim 1, characterized in that, in, The electricity information also includes preset electricity price information; The determination of multiple electricity price periods based on the electricity information includes: Based on the historical peak-valley electricity price information or the preset electricity price information, predict the time periods of each high-electricity-price period and each low-electricity-price period during the weekday for the energy storage device.

3. The method according to claim 1, characterized in that, in, The high electricity price period includes peak hours and high-peak hours, and the low electricity price period includes flat hours and low-peak hours; Determining the charging and discharging status of the energy storage device during each electricity price period includes: The energy storage device is configured to discharge at maximum output power during peak hours, discharge at a rated power of (N-N1) / h2 during high-peak hours, charge at a rated power of N / h3 during low-peak hours, and charge at a rated power of N / h4 during flat-peak hours. Wherein, N is the total energy storage of the energy storage device, N1 is the output energy of the energy storage device during the peak period of the energy storage device on the working day, h2 is the duration of the peak period of the energy storage device on the working day, h3 is the duration of the valley period of the energy storage device on the working day, and h4 is the duration of the flat period of the energy storage device on the working day.

4. The method according to claim 3, characterized in that, Determining the charging and discharging status of the energy storage device during each electricity price period also includes: During the off-peak and normal periods, the energy storage device is charged, and when the energy storage capacity of the energy storage device is detected to be greater than the preset energy storage capacity, the charging of the energy storage device is restricted or stopped.

5. The method according to claim 3, characterized in that, The method further includes: During the working days of the energy storage device, the power demand for the current period and the next period is predicted based on the power forecasting model. Based on the power demand and the target charging and discharging strategy, it is determined whether to switch the charging and discharging state of the energy storage device in the next period.

6. The method according to claim 1, characterized in that, When the energy storage device is in the charging state of the charging and discharging state, it is charged at the lowest charging rate.

7. A control device for an energy storage device, characterized in that, The device is used in an energy storage device, and the device includes: The acquisition module is used to acquire power information and determine multiple electricity price periods for the energy storage device on a working day based on the power information; wherein, the power information includes historical electricity price trends, and the electricity price periods include high electricity price periods and low electricity price periods; The first strategy determination module is used to generate a preliminary charge and discharge strategy based on the multiple electricity price periods; wherein, the preliminary charge and discharge strategy includes: the energy storage device is configured to discharge mode during the high electricity price period and to charge mode during the low electricity price period; The second strategy determination module is used to determine the charge-discharge switching frequency based on the preliminary charge-discharge strategy, determine the target charge-discharge strategy of the energy storage device based on the charge-discharge switching frequency and the duration of the multiple electricity price periods, and determine the charge-discharge status of the energy storage device in each electricity price period. The second strategy determination module is further configured to, when the charging / discharging switching frequency is greater than a preset switching frequency threshold, control the energy storage device to maintain the same charging or discharging state as the adjacent time period during the target electricity price period; wherein the target electricity price period is an electricity price period with a duration less than a preset duration threshold; or, control the energy storage device to be in a closed state during a high electricity price period with a duration less than the preset duration threshold; or, merge multiple consecutive time periods with a duration less than the preset duration threshold, determine the average electricity price in the merged time period, and determine whether the energy storage device is in a charging or discharging state during the merged time period based on the average electricity price.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions that, when executed by a processor, perform the steps of the method according to any one of claims 1-6.

9. An energy storage device, characterized in that, The energy storage device includes a battery, a memory, and a processor. The battery is used to store electrical energy, the memory stores program instructions, and when the processor runs the program instructions, it performs the steps of the method according to any one of claims 1-6.

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