An intelligent charge and discharge management method for an energy storage device

Abstract

The present application provides an intelligent charge-discharge management method for an energy storage device, which relates to the field of energy storage technology. The method includes obtaining the operation logic; taking the rated power of the PCS as Pmax and the optimal power as Pmin; determining the charging duration and the discharging duration according to the charge-discharge time interval, and obtaining the rated system power E; calculating the theoretical charging power based on Pmax, Pmin and the charging duration; calculating the theoretical discharging power based on Pmax, Pmin and the discharging duration; determining the theoretical charge-discharge power P; performing charge-discharge power calculation on P, Pmax and Pmin to obtain the target execution charge-discharge power P'. The present application solves the technical problem that the charge-discharge control strategy of traditional energy storage devices lacks accuracy and flexibility, resulting in limited improvement of energy conversion efficiency, and achieves the technical effects of optimizing energy utilization efficiency and extending the service life of the battery.

Description

Technical Field

[0001] This application relates to the technical field of energy storage, and particularly to an intelligent charge-discharge management method for an energy storage device. Background Art

[0002] With the rapid development and popularization of renewable energy, the wind-solar-storage system, as an important part of the energy field, has been more and more widely used. As the core component of the wind-solar-storage system, the charge-discharge control strategy of the energy storage device is of great significance for improving the system operation efficiency, optimizing energy use, and ensuring the safe and stable operation of the system.

[0003] In the current industrial and commercial energy storage systems, the optimization of the charge-discharge strategy mainly focuses on demand response scheduling to meet the needs of the power grid and users. The efficiency optimization in the specific charge-discharge process of the energy storage device is often ignored. The traditional charge-discharge control strategies of energy storage devices mostly make decisions based on simple rules or thresholds, and it is difficult to achieve the optimal battery charge-discharge efficiency. Since the working efficiency of the battery and PCS is directly related to the overall performance and energy utilization efficiency of the energy storage system, this kind of neglect may lead to the fact that the performance of the energy storage system is not optimal in practical applications. Especially in a complex industrial and commercial environment, the battery and PCS may face frequent and drastic changes in charge-discharge demands. The lack of efficiency optimization for these specific scenarios may lead to unstable system operation and even shorten the device life. Summary of the Invention

[0004] This application provides an intelligent charge-discharge management method for an energy storage device, which solves the technical problem that the charge-discharge strategies of traditional industrial and commercial energy storage systems often focus on the macro-level power grid and user demand response, ignoring the refined management at the energy storage device level, and the charge-discharge control strategies of the device lack accuracy and flexibility, resulting in limited improvement in energy conversion efficiency, and achieves the technical effects of optimizing energy utilization efficiency and extending the battery service life.

[0005] In view of the above problems, the present application provides an intelligent charge and discharge management method for an energy storage device. The method includes: obtaining an operation logic, where the operation logic includes a first priority, a second priority, a third priority, and a fourth priority; inputting the rated power Pe of the PCS based on the operation logic, setting an optimal power according to the rated power Pe of the PCS, taking the rated power of the PCS as Pmax, and the optimal power as Pmin; inputting a charge and discharge time interval, determining a charge duration and a discharge duration according to the charge and discharge time interval, and obtaining the rated power E of the system; when the charge stage logic is in effect, performing power calculation based on Pmax, Pmin, and the charge duration to obtain a theoretical charge power; when the discharge stage logic is in effect, performing power calculation based on Pmax, Pmin, and the discharge duration to obtain a theoretical discharge power; determining a theoretical charge and discharge power P according to the theoretical charge power and the theoretical discharge power; performing charge and discharge power calculation on the theoretical charge and discharge power P, Pmax, and Pmin to obtain a target execution charge and discharge power P'.

[0006] One or more technical solutions provided in the present application have at least the following technical effects or advantages:

[0007] Obtaining an operation logic, where the operation logic includes a first priority, a second priority, a third priority, and a fourth priority; inputting the rated power Pe of the PCS based on the operation logic, setting an optimal power according to the rated power Pe of the PCS, taking the rated power of the PCS as Pmax, and the optimal power as Pmin; inputting a charge and discharge time interval, determining a charge duration and a discharge duration according to the charge and discharge time interval, and obtaining the rated power E of the system; when the charge stage logic is in effect, performing power calculation based on Pmax, Pmin, and the charge duration to obtain a theoretical charge power; when the discharge stage logic is in effect, performing power calculation based on Pmax, Pmin, and the discharge duration to obtain a theoretical discharge power; determining a theoretical charge and discharge power P according to the theoretical charge power and the theoretical discharge power; performing charge and discharge power calculation on the theoretical charge and discharge power P, Pmax, and Pmin to obtain a target execution charge and discharge power P'.

[0008] In summary, based on the battery principle and the PCS principle, the present application optimizes the charge and discharge process with secondary subdivision under the demand response scheduling strategy. Through precise calculation and priority logic, it realizes the refined management of the charge and discharge process, reduces the overcharge, over-discharge, and uneven charge and discharge of the battery, ensures that the battery and the PCS reach the highest efficiency during the actual operation process, not only significantly improves the energy utilization efficiency and performance of the industrial and commercial energy storage system, but also extends the equipment life and enhances the stability of the energy storage system.

[0009] 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, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of this application more obvious and understandable, the specific embodiments of this application are specifically given below. Description of the Drawings

[0010] Figure 1 It is a schematic flowchart of a method for intelligent charge and discharge management of an energy storage device provided by an embodiment of this application;

[0011] Figure 2 It is a schematic flowchart of the specific execution steps of the second priority level in a method for intelligent charge and discharge management of an energy storage device provided by an embodiment of this application;

[0012] Figure 3 It is a schematic flowchart of a process for obtaining the target execution charge and discharge power P' in a method for intelligent charge and discharge management of an energy storage device provided by an embodiment of this application. Detailed Description of the Invention

[0013] By providing a method for intelligent charge and discharge management of an energy storage device in an embodiment of this application, the technical problem that the charge and discharge strategies of traditional industrial and commercial energy storage systems often focus on the macro-level power grid and user demand response, ignoring the refined management at the energy storage device level, and the charge and discharge control strategies of the device lack accuracy and flexibility, resulting in limited improvement of the energy conversion efficiency, is solved, and the technical effects of optimizing the energy utilization efficiency and extending the battery service life are achieved.

[0014] As Figure 1 shown, an embodiment of this application provides a method for intelligent charge and discharge management of an energy storage device, and the method includes:

[0015] Step S1: Obtain an operation logic, where the operation logic includes a first priority, a second priority, a third priority, and a fourth priority.

[0016] Specifically, first, obtain the operation logic, that is, determine a series of operation rules and priority orders that the energy storage device should follow during the charge and discharge process. These rules and priorities are the basis of the intelligent charge and discharge management method and are used to guide the system's behavior decision-making in different situations.

[0017] The operation logic includes four priorities: the first priority, the second priority, the third priority, and the fourth priority. These priorities are used to distinguish the urgency and importance of different operations. The first priority is the determination of demand management, that is, by intelligently scheduling the charge and discharge operations of energy storage devices to respond to the grid demand, which belongs to the macro-level regulation and control. This part is not involved in this embodiment. The second priority is the DOD interval setting, which focuses on the health management and service life of the battery. The system will dynamically adjust the upper and lower limits of DOD according to the battery characteristics, such as chemical properties, design capacity, etc., and the current operation requirements. By setting a reasonable DOD interval, overcharging and over-discharging of the battery can be avoided, thereby extending the cycle life and overall performance of the battery. The third priority is the current limiting at the end of charge and discharge, that is, when the charge and discharge process of the battery is approaching the end, the charging current or discharge current is limited to prevent overcharging or over-discharging of the battery and further protect the battery health. The fourth priority is the intelligent charge and discharge strategy. The system will combine strategies such as demand management, DOD interval setting, and end current limiting to formulate the most suitable charge and discharge plan. Through the setting of the above four priorities, the energy storage system can achieve intelligent charge and discharge management of energy storage devices while meeting the requirements of grid demand management, battery health management, charge and discharge safety, and system efficiency optimization, and improve the energy utilization efficiency.

[0018] Further, as Figure 2 shown, the specific implementation steps of the second priority in step S1 of the embodiment of the present application are:

[0019] Judge whether to limit according to the DOD in the 5% - 100% SOC interval; if so, select the 5% SOC voltage value as the minimum voltage value and the 100% SOC voltage value as the maximum voltage value for limitation according to the corresponding relationship table between different SOC and voltage; if not, judge whether to limit according to the voltage values corresponding to the 2% - 100% SOC interval; if so, select the 2% SOC voltage value as the minimum voltage value and the 100% SOC voltage value as the maximum voltage value for limitation according to the corresponding relationship table between different SOC and voltage, and if not, customize the SOC interval and voltage value to limit the charge and discharge interval.

[0020] Specifically, SOC, that is, state of charge, is an indicator to measure the remaining battery power, usually expressed as a percentage. 100% SOC means the battery is fully charged, while 0% SOC means the battery is completely discharged. DOD, that is, depth of discharge, refers to the discharge ratio relative to its maximum capacity when the battery discharges to a certain state. For example, if a battery discharges from 100% SOC to 50% SOC, then its DOD is 50%. The SOC-voltage correspondence table is a data table that records the voltage values corresponding to different SOC levels of the battery. Since the voltage of the battery changes with the change of SOC, this correspondence is crucial for accurately monitoring the battery state and optimizing the charge and discharge strategies.

[0021] First, it is judged whether to limit the DOD in the SOC range of 5% - 100%. This judgment is usually based on the operating logic of the system and the current battery health status. If it is decided to limit the DOD in the SOC range of 5% - 100%, the voltage value corresponding to 5% SOC is selected from the SOC-voltage correspondence table as the minimum voltage value, and the voltage value corresponding to 100% SOC is selected as the maximum voltage value to limit the charge and discharge operations to avoid over-discharging or over-charging of the battery. That is, the system stops charging and discharging when the highest voltage of a single cell ≤ Vmax during charging or the lowest voltage of a single cell ≥ Vmin during discharging.

[0022] If the judgment result of the first step is negative, that is, not to limit the DOD in the SOC range of 5% - 100%, continue the second-round judgment to ask whether to limit according to the voltage values corresponding to the SOC range of 2% - 100%. If so, the voltage value corresponding to 2% SOC is selected from the SOC-voltage correspondence table as the minimum voltage value, and the voltage value corresponding to 100% SOC is selected as the maximum voltage value for charge and discharge interval limitation.

[0023] If the judgment results of the previous two rounds are both negative, the system allows the operator to customize the SOC range and its corresponding voltage values to more flexibly manage the charge and discharge operations and adapt to specific operating requirements or battery characteristics.

[0024] Through the above steps, the energy storage system can intelligently limit the charge and discharge process according to the SOC level of the battery, thereby protecting the battery, extending its service life, and ensuring the safe and stable operation of the system.

[0025] Furthermore, the specific implementation steps of the third priority in step S1 of the embodiment of the present application are as follows:

[0026] Determine whether the maximum real-time voltage Vmax of battery charging ≥ Vmax - 20 mV. If it is satisfied, adjust the small power at the end of charging to 10 kW. If not, no operation is performed. Determine whether the maximum real-time voltage Vmin of battery discharging ≥ Vmin + 20 mV. If it is satisfied, adjust the small power at the end of discharging to 10 kW. If not, no operation is performed.

[0027] Specifically, the small power at the end of charging and the small power at the end of discharging refer to that when the battery is close to the end of charge and discharge, the system will reduce the charging or discharging power to a relatively small level to prevent overcharging or over-discharging of the battery and protect the battery health. The small power at the end of charging and the small power at the end of discharging are usually set to a fixed value, that is, 10 kW, to ensure that the battery can complete the charge and discharge process in a more gentle manner when it is close to the full charge or empty charge state.

[0028] Continuously monitor the maximum real-time voltage Vmax(real-time) and the minimum real-time voltage Vmin(real-time) of the battery during the charge and discharge process. These data are collected and processed in real time by the battery management system (BMS). During the charging process, determine whether the maximum real-time voltage Vmax(real-time) of battery charging is greater than or equal to Vmax - 20 mV. During the discharging process, determine whether the minimum real-time voltage Vmin(real-time) of battery discharging is greater than or equal to Vmin + 20 mV. Among them, Vmax and Vmin are the voltage thresholds preset by the system in the second priority to identify whether the battery is close to the end of its charge and discharge. If the judgment result is yes, it indicates that the battery is close to the end of charge and discharge, and the system will automatically adjust the small power at the end of charging or the small power at the end of discharging to the preset value of 10 kW. This adjustment is completed through the communication and control between the battery management system and the PCS to achieve precise control of the charge and discharge power. If the judgment result is no, it indicates that the battery is not close to the end of charge and discharge, and the system will maintain the current charge and discharge power level, that is, no operation.

[0029] In the above steps, by real-time monitoring the voltage state of the battery and starting the current-limiting protection measures when the battery is close to the end of its charge and discharge, the energy storage system can effectively protect the battery health and extend the battery service life.

[0030] Step S2: Based on the operating logic, input the rated power Pe of the PCS, set the optimal power according to the rated power Pe of the PCS, use the rated power Pe of the PCS as Pmax, and the optimal power as Pmin.

[0031] Specifically, the rated power Pe refers to the maximum power output capacity when the PCS (power conversion system) is designed, that is, the maximum power that the system can continuously provide. The optimal power Pmin refers to the best working power set according to the actual operating requirements on the premise of ensuring the efficient operation of the PCS. This power is usually lower than the rated power of the PCS to ensure that the system operates within the range of high efficiency and safety.

[0032] First, obtain the rated power Pe of the PCS. This information usually comes from the manufacturer's technical specifications of the PCS or the system design document. Based on the operating logic, take the rated power Pe of the PCS as the maximum power Pmax for the system's charge and discharge operations, which means the maximum power output that the system can reach when necessary. Then, based on the operating logic and actual requirements, calculate and set the optimal power Pmin. Through this step, the energy storage system can intelligently adjust its power output according to the actual operating requirements to ensure operation under the premise of high efficiency and safety.

[0033] Furthermore, the method described in the embodiment of the present application further includes:

[0034] Judge whether the rated power Pe of the PCS is greater than the preset power. If so, Pmin is 0.3 * Pe; if not, Pmin is 0.6 * Pe.

[0035] Specifically, the preset power is a predefined threshold used for comparison and decision-making to determine the setting of the optimal power Pmin. It reflects the preset judgment of the system designer on the relationship between the rated power Pe of the PCS and the optimal power Pmin or the system requirements.

[0036] The determination process of the optimal power Pmin includes: comparing the rated power Pe of the PCS with the preset power. When the rated power Pe is greater than the preset power, then the optimal power Pmin will be set to 0.3 times Pe; conversely, if Pe is less than or equal to the preset power, Pmin is set to 0.6 times Pe. This decision-making process aims to dynamically adjust the minimum power of the system operation according to the actual capacity of the PCS and the system requirements to achieve more efficient and safer energy management. Among them, 0.3 times and 0.6 times are the recommended values of this embodiment. In the specific implementation process, those skilled in the art can adjust according to the actually used PCS.

[0037] Step S3: Input the charge and discharge time intervals. According to the charge and discharge time intervals, determine the charge duration and discharge duration, and obtain the system rated power E.

[0038] Specifically, the charge and discharge time intervals refer to the time periods when the system plans to perform charge or discharge operations, usually represented by specific time points or time periods, such as "from 8 am to 10 am" or "from 10 pm to 2 am the next day". The charge duration refers to the time length during which the energy storage system actually performs charging within the charge time interval. The discharge duration refers to the time length during which the energy storage system actually performs discharging within the discharge time interval. The system rated power E refers to the maximum power capacity designed for the energy storage system, usually in kilowatt-hours (kWh).

[0039] The user or system inputs the charge and discharge time intervals through the user interface or the automatic scheduling system, and uses programming languages or time series analysis tools, such as the Datetime and Pandas libraries in Python, the ts or xts packages in R language, etc. to analyze the input time intervals, parse, transform and calculate the time data, and calculate the actual charge duration and discharge duration to ensure the accuracy and effectiveness of the time information. The system obtains the rated power E from its configuration parameters, which is usually determined in the system design stage and is an important reference for the performance of the energy storage system. Exemplarily, assume that the system plans to perform a discharge operation from 4 pm to 8 pm every day to respond to the peak demand of the power grid. Analyze the time interval and determine that the discharge duration is 4 hours. At the same time, the rated power E of the system is 1000 kWh. Based on this information, the system formulates a discharge strategy.

[0040] This step obtains the specific charge and discharge duration information and the system rated power, providing the necessary data support for the formulation of the subsequent charge strategy.

[0041] Step S4: When in the charging stage logic, based on the Pmax, Pmin and the charging duration, perform power calculation to obtain the theoretical charging power.

[0042] Specifically, when the energy storage device is in the charging stage, according to the Pmax and Pmin determined in step S2 and the charging duration determined in step S3, use mathematical formulas to calculate the theoretical charging power to ensure that the system can operate efficiently and safely during the charging stage.

[0043] Furthermore, step S4 of the embodiment of the present application further includes:

[0044] Judge that the battery power < 100%, then P = (E * 1.2) * (1 - SOC) / charging duration, where SOC is the starting SOC value before system charging, and 1.2 is the charging compensation coefficient; if P ≥ Pmax, then the theoretical charging power P = Pmax, if P ≤ Pmin, then the theoretical charging power P = Pmin, if Pmax > P > Pmin, then the theoretical charging power P = P.

[0045] Specifically, the specific process of calculating the theoretical charging power includes: First, determine whether the current battery charge is less than 100%, that is, whether the battery is in a non-full charge state. This is the trigger condition for calculating the theoretical charging power P. When the battery charge is less than 100%, the system calculates the theoretical charging power P based on the following formula: P = (E * 1.2) * (1 - SOC) / charging duration, where E is the rated battery capacity obtained in step S3, SOC is the starting SOC value before system charging, and 1.2 is the charging compensation coefficient. This coefficient is used to consider factors such as charging efficiency loss and battery health maintenance in the calculation of the theoretical charging power to ensure that the system can achieve the expected charging effect during actual operation.

[0046] The calculated theoretical charging power P needs to be further compared with the system maximum power Pmax and the minimum power Pmin to ensure that the theoretical charging power P falls within the power range for the safe operation of the system. If P is greater than or equal to Pmax, then Pmax is set as the final theoretical charging power; if P is less than or equal to Pmin, then Pmin is set as the final theoretical charging power; if P is between Pmin and Pmax, then the theoretical charging power P remains unchanged as the value calculated by the formula.

[0047] Exemplarily, the battery charge is 80% (i.e., SOC = 0.8), the system maximum power Pmax is 500 kW, the minimum power Pmin is 100 kW, and the planned charging duration is 3 hours. According to the system rated battery capacity E = 1000 kWh and the charging compensation coefficient 1.2, calculate the theoretical charging power P: P = (1000 × 1.2) × (1 - 0.8) / 3 = 80 kW. Since 80 kW is between Pmin and Pmax, the theoretical charging power P remains 80 kW. Through this step, the energy storage system can dynamically adjust the theoretical charging power according to the actual state of the battery and the charging conditions, providing accurate data support for the subsequent calculation of the actual operating power.

[0048] Step S5: When in the discharge stage logic, perform power calculation based on the Pmax, Pmin, and the discharge duration to obtain the theoretical discharge power.

[0049] Specifically, when the energy storage device is in the discharge stage, according to the Pmax and Pmin determined in step S2 and the discharge duration determined in step S3, use a mathematical formula to calculate the theoretical discharge power to ensure that the system can operate efficiently and safely during the discharge stage.

[0050] Furthermore, step S5 of the embodiment of the present application further includes:

[0051] If it is determined that the battery power < 100%, then P = (E * 1.1) * (1 - SOC) / discharge duration, where SOC is the starting SOC value before system discharge, and 1.1 is the discharge compensation coefficient; if P > Pmax, then the theoretical discharge power P = Pmax, if P < Pmin, then the theoretical discharge power P = Pmin, if Pmax > P > Pmin, then the theoretical discharge power P = P.

[0052] Specifically, the specific process of calculating the theoretical discharge power includes: first, determining whether the current battery power is less than 100%, that is, whether the battery is in a non-full state. This is the trigger condition for calculating the theoretical discharge power P. When the battery power is less than 100%, the system calculates the theoretical discharge power P based on the following formula: P = (E * 1.1) * (1 - SOC) / discharge duration, where E is the system rated power, obtained in step S3, SOC is the starting SOC value before system discharge, and 1.1 is the discharge compensation coefficient. This coefficient is used to consider factors such as discharge efficiency loss and battery health maintenance in the calculation of the theoretical discharge power, ensuring that the system can achieve the expected discharge effect during actual operation.

[0053] The calculated theoretical discharge power P needs to be further compared with the system maximum power Pmax and minimum power Pmin to ensure that the theoretical discharge power P falls within the power range for the safe operation of the system. If P is greater than or equal to Pmax, then Pmax is set as the final theoretical discharge power; if P is less than or equal to Pmin, then Pmin is set as the final theoretical discharge power; if P is between Pmin and Pmax, then the theoretical discharge power P remains unchanged, which is the value calculated by the formula. Through this step, the energy storage system can dynamically adjust the theoretical discharge power according to the actual state of the battery and discharge conditions, providing accurate data support for the subsequent calculation of the actual operation power.

[0054] Step S6: Determine the theoretical charge-discharge power P according to the theoretical charge power and the theoretical discharge power.

[0055] Specifically, the theoretical charge-discharge power P is the theoretical operating power of the system during a specific charge-discharge cycle. It is one of the key indicators for formulating the operation strategy of the energy storage system. Analyze the charge-discharge requirements during a specific charge-discharge time interval. When the energy storage device is in the charging stage, the theoretical charge-discharge power is the theoretical charge power determined in step S4. When the energy storage device is in the discharging stage, the theoretical charge-discharge power is the theoretical discharge power determined in step S5. Perform subsequent target execution charge-discharge power calculation according to the theoretical charge-discharge power.

[0056] Step S7: Perform charge-discharge power calculation on the theoretical charge-discharge power P, the Pmax, and Pmin to obtain the target execution charge-discharge power P'.

[0057] Specifically, based on the theoretical charge-discharge power P, Pmax, and Pmin determined according to the foregoing steps, the target execution charge-discharge power P' is determined through comparison judgment and mathematical formula calculation. Among them, the target execution charge-discharge power P' refers to the actual execution power value of the system during the charge-discharge cycle.

[0058] Furthermore, as Figure 3 shown, step S7 of the embodiment of the present application further includes:

[0059] Judge whether the theoretical charge-discharge power P satisfies P = Pmax. If it satisfies, then P' = P * 1.05; if it does not satisfy, calculate according to the power interval where P is located to obtain a set of power calculation intervals. The set of power calculation intervals includes X * Pe > P ≥ (X - 0.1) * Pe, X * Pe ≤ P ≥ Pmin, P < Pmin, where X = 1 is the rated power coefficient, and cycle X = (X - 0.1) until X = Pmin / Pe; according to the set of power calculation intervals, determine a set of charge-discharge power calculation formulas; based on the set of charge-discharge power calculation formulas, perform charge-discharge power calculations respectively to obtain the target execution charge-discharge power P'.

[0060] Specifically, the specific calculation process of the target execution charge-discharge power P' includes: First, judge whether the theoretical charge-discharge power is equal to the maximum charge-discharge power Pmax. If P is equal to Pmax, the target execution charge-discharge power P' is 1.05 times of Pmax, that is, P' = P * 1.05, that is, the actual power sent to the system for execution is 5% more than the power of the PCS, and full charge and full discharge are given priority. In this process, it is necessary to determine whether the PCS can operate overload for a long time, otherwise Pmax needs to be reset.

[0061] If P = Pmax is not satisfied, a series of power calculation intervals are determined according to the relationship between the theoretical charge-discharge power P, the rated power Pe, and the minimum power Pmin, and a set of power calculation intervals is obtained. The set of power calculation intervals includes X * Pe > P ≥ (X - 0.1) * Pe, X * Pe ≤ P ≥ Pmin, P < Pmin, where X = 1 is the rated power coefficient, and cycle X = (X - 0.1) until X = Pmin / Pe, that is, the theoretical charge-discharge power is divided into steps at an interval of 0.1Pe to obtain multiple power calculation intervals such as (Pe, 0.9 * Pe], (0.9 * Pe, 0.8 * Pe], (0.8 * Pe, 0.7 * Pe], (0.7 * Pe, 0.6 * Pe], (0.6 * Pe, 0.5 * Pe], …, less than Pmin. According to the above set of power calculation intervals, corresponding charge-discharge power calculation formulas are defined. These formulas will calculate the target execution charge-discharge power P' according to the relationship between the theoretical power P and the system parameters.

[0062] Preferably, in step S7 of the embodiments of the present application, determining the set of charge-discharge power calculation formulas includes:

[0063] When the power calculation interval set is X*Pe > P ≥ (X - 0.1)*Pe or X*Pe ≤ P ≥ Pmin, determine SOC(0, 45], SOC(45, 60] and SOC(60, 100]; according to the SOC(0, 45], SOC(45, 60] and SOC(60, 100], respectively determine the set of charge-discharge power calculation formulas P' = P(2 - n), P' = P, P' = P*n, where n is the charge-discharge coefficient, selected according to actual test experience values, and satisfying P*n ≤ Pmax*1.05.

[0064] Preferably, in step S7 of the embodiments of the present application, determining the set of charge-discharge power calculation formulas further includes:

[0065] When the power calculation interval set is P < Pmin, determine SOC[60, 100], SOC(45, 60) and SOC[0, 45]; according to the SOC[60, 100], SOC(45, 60) and SOC[0, 45], respectively determine the set of charge-discharge power calculation formulas P' = P*n, P' = P and P' = P*(2 - n).

[0066] Specifically, according to the power calculation interval where the theoretical charge-discharge power P is located, and the SOC value of the battery, determine the corresponding charge-discharge power calculation formula in the set of charge-discharge power calculation formulas, and calculate the target execution charge-discharge power P'. The specific process includes:

[0067] First, according to the relationship between the theoretical charge-discharge power P and the system parameters, determine the SOC interval division. When X*Pe > P ≥ (X - 0.1)*Pe or X*Pe ≤ P ≥ Pmin, the SOC intervals are (0, 45], (45, 60] and (60, 100]; when the power calculation interval set is P < Pmin, the SOC intervals are [60, 100], (45, 60) and [0, 45].

[0068] Next, based on the determined SOC intervals, define different charge-discharge power calculation formulas. The specific formulas include: when X*Pe > P ≥ (X - 0.1)*Pe or X*Pe ≤ P ≥ Pmin, when SOC is in the interval (0, 45], the calculation formula is P' = P*(2 - n); when SOC is in the interval (45, 60], the calculation formula is P' = P; when SOC is in the interval (60, 100], the calculation formula is P' = P*n.

[0069] When P < Pmin, when the SOC is in the range of [60, 100], the calculation formula is P' = P * n; when the SOC is in the range of (45, 60), the calculation formula is P' = P; when the SOC is in the range of [0, 45], the calculation formula is P' = P * (2 - n).

[0070] Among them, n is the charge-discharge coefficient. Based on the actual test experience value, when adjusting the charge-discharge coefficient n, it is necessary to satisfy P * n ≤ Pmax * 1.05. To ensure that the adjusted theoretical charge-discharge power P * n does not exceed 1.05 times the maximum power Pmax. This is to ensure that the system operates within a safe range, while considering the battery state and system efficiency.

[0071] Through the above steps, the energy storage system can dynamically adjust the charge-discharge power according to the relationship between the theoretical charge-discharge power P and the maximum power Pmax, so as to ensure that the total power output during the charge-discharge process of the system is both efficient and safe, and improve the energy utilization efficiency.

[0072] In summary, the intelligent charge-discharge management method of an energy storage device provided by the embodiments of the present application has the following technical effects:

[0073] Obtain the operation logic, where the operation logic includes the first priority, the second priority, the third priority, and the fourth priority; based on the operation logic, input the rated power Pe of the PCS, set the optimal power according to the rated power Pe of the PCS, use the rated power of the PCS as Pmax, and the optimal power as Pmin; input the charge-discharge time interval, determine the charge duration and discharge duration according to the charge-discharge time interval, and obtain the rated power E of the system; when the charging stage logic is in effect, perform power calculation based on the Pmax, Pmin, and the charge duration to obtain the theoretical charging power; when the discharging stage logic is in effect, perform power calculation based on the Pmax, Pmin, and the discharge duration to obtain the theoretical discharging power; determine the theoretical charge-discharge power P according to the theoretical charging power and the theoretical discharging power; perform charge-discharge power calculation on the theoretical charge-discharge power P, the Pmax, and Pmin to obtain the target execution charge-discharge power P'.

[0074] Overall, the embodiments of the present application optimize the charge-discharge process with secondary subdivision under the demand response scheduling strategy based on the battery principle and the PCS principle. Through precise calculation and priority logic, the refined management of the charge-discharge process is realized, reducing the overcharge, over-discharge, and uneven charge-discharge of the battery, ensuring that the battery and the PCS reach the highest efficiency during the actual working process, not only significantly improving the energy utilization efficiency and performance of the industrial and commercial energy storage system, but also extending the equipment life and enhancing the stability of the energy storage system.

[0075] The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An intelligent charge and discharge management method for an energy storage device, characterized in that, The method includes: Obtain the operation logic, where the operation logic includes a first priority, a second priority, a third priority, and a fourth priority; Based on the operation logic, input the rated power Pe of the PCS, set the optimal power according to the rated power Pe of the PCS, take the rated power of the PCS as Pmax, and the optimal power as Pmin; Input the charge and discharge time intervals, determine the charge duration and discharge duration according to the charge and discharge time intervals, and obtain the rated system power E; When in the charging stage logic, perform power calculation based on Pmax, Pmin, and the charge duration to obtain the theoretical charging power; When in the discharging stage logic, perform power calculation based on Pmax, Pmin, and the discharge duration to obtain the theoretical discharging power; Determine the theoretical charge and discharge power P according to the theoretical charging power and the theoretical discharging power; Perform charge and discharge power calculation on the theoretical charge and discharge power P, Pmax, and Pmin to obtain the target execution charge and discharge power P'; The obtaining of the theoretical charging power includes: Judge that the battery power < 100%, then P = (E * 1.2) * (1 - SOC) / charge duration, where SOC is the starting SOC value before system charging, and 1.2 is the charging compensation coefficient; If P ≥ Pmax, then the theoretical charging power P = Pmax; if P ≤ Pmin, then the theoretical charging power P = Pmin; if Pmax > P > Pmin, then the theoretical charging power P = P; The obtaining of the theoretical discharging power includes: Judge that the battery power < 100%, then P = (E * 1.1) * (1 - SOC) / discharge duration, where SOC is the starting SOC value before system discharging, and 1.1 is the discharging compensation coefficient; If P > Pmax, then the theoretical discharging power P = Pmax; if P < Pmin, then the theoretical discharging power P = Pmin; if Pmax > P > Pmin, then the theoretical discharging power P = P; The obtaining of the target execution charge and discharge power P' includes: Judge whether the theoretical charge and discharge power P satisfies P = Pmax. If it satisfies, then P' = P * 1.05; If it does not satisfy, then calculate according to the power interval where P is located to obtain the power calculation interval set. The power calculation interval set includes X * Pe > P ≥ (X - 0.1) * Pe, X * Pe ≤ P ≥ Pmin, P < Pmin, where X = 1 is the rated power coefficient, and loop X = (X - 0.1) until X = Pmin / Pe; Determine the charge and discharge power calculation formula set according to the power calculation interval set; Perform charge and discharge power calculation respectively based on the charge and discharge power calculation formula set to obtain the target execution charge and discharge power P'.

2. The intelligent charge and discharge management method of an energy storage device according to claim 1, characterized in that, The specific execution steps of the second priority are: Judge whether to limit according to the DOD in the 5% - 100% SOC interval; If so, select the 5% SOC voltage value as the minimum voltage value and the 100% SOC voltage value as the maximum voltage value for limitation according to the corresponding relationship table of different SOC and voltage. If not, determine whether to limit according to the voltage values corresponding to the SOC range of 2% to 100%. If so, select the 2% SOC voltage value as the minimum voltage value and the 100% SOC voltage value as the maximum voltage value for limitation according to the different SOC-voltage correspondence table. If not, customize the SOC range and voltage value to limit the charge and discharge range.

3. The intelligent charge and discharge management method of an energy storage device according to claim 1, characterized in that, The specific implementation steps of the third priority are as follows: Determine whether the maximum real-time voltage Vmax of battery charging ≥ Vmax - 20mV. If satisfied, adjust the small power at the end of charging to 10kW. If not satisfied, no operation is performed. Determine whether the maximum real-time voltage Vmin of battery discharging ≥ Vmin + 20mV. If satisfied, adjust the small power at the end of discharging to 10kW. If not satisfied, no operation is performed.

4. The intelligent charge and discharge management method of an energy storage device according to claim 1, characterized in that The method includes: Determine whether the rated power Pe of the PCS is greater than the preset power. If so, Pmin is 0.3 * Pe. If not, Pmin is 0.6 * Pe.

5. The intelligent charge and discharge management method of an energy storage device according to claim 1, characterized in that, The determination of the charge and discharge power calculation formula set includes: When the power calculation interval set is X * Pe > P ≥ (X - 0.1) * Pe or X * Pe ≤ P ≥ Pmin, determine SOC(0, 45], SOC(45, 60] and SOC(60, 100].[[]END]] According to the SOC(0, 45], SOC(45, 60] and SOC(60, 100], respectively determine the charge and discharge power calculation formula sets P' = P(2 - n), P' = P, P' = P * n, where n is the charge and discharge coefficient, which is selected according to the actual test experience value and satisfies P * n ≤ Pmax * 1.

05.

6. The intelligent charge and discharge management method for an energy storage device according to claim 5, characterized in that, The determination of the charge and discharge power calculation formula set includes: When the power calculation interval set is P < Pmin, determine SOC[60, 100], SOC(45, 60) and SOC[0, 45].[[]END]] According to the SOC[60, 100], SOC(45, 60) and SOC[0, 45], respectively determine the charge and discharge power calculation formula sets P' = P * n, P' = P and P' = P * (2 - n).

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