Power supply method and terminal after battery feeding of energy storage system

Abstract

This invention relates to the field of battery charging, and more particularly to a method and terminal for charging a battery in an energy storage system after it has been depleted. The method includes: when a battery depletion is detected, prohibiting battery charging and discharging; if a safety signal is received, resetting to resume battery charging and prohibiting discharging, configuring the battery to perform a first-stage charging at a preset low-rate charging current; if the individual cell voltage of the battery is greater than a first voltage threshold, stopping charging and allowing the battery to rest for a preset time; determining whether the individual cell voltage of the battery is stable after the preset resting time; if so, performing a second-stage charging at a low-rate charging current until the individual cell voltage reaches a second voltage threshold, then stopping charging and allowing the battery to rest, where the second voltage threshold is greater than the first voltage threshold; otherwise, returning to the step of performing the first-stage charging at a low-rate charging current. This invention does not require additional equipment for charging, increasing the portability of the charging process.

Description

Technical Field

[0001] This invention relates to the field of battery replenishment technology, and in particular to a method and terminal for replenishing the battery of an energy storage system after it has been depleted. Background Technology

[0002] In existing technologies, with the rapid development of the energy storage industry, various battery products are widely used. However, batteries generally suffer from performance degradation and capacity reduction after long-term use, which directly leads to devices being more prone to insufficient power, or even battery depletion (i.e., the battery is over-discharged below the cutoff voltage). Once a battery is depleted, it will trigger a series of serious consequences, including but not limited to permanent capacity decay, shortened cycle life, internal structural damage, increased risk of thermal runaway, and decreased reliability of the entire energy storage system. To prevent battery depletion, conventional technologies mainly rely on the battery management system (BMS) to monitor the battery status in real time, combined with regular charge-discharge maintenance, to prevent over-discharge. However, these preventative measures cannot completely eliminate the occurrence of battery depletion. When battery depletion actually occurs, existing technologies usually require removing the depleted battery pack from the energy storage system and using additional dedicated charging equipment to charge it separately. This method has significant drawbacks: the operation process is cumbersome, consumes a lot of time and manpower, the charging cost is high, and the portability is poor due to the need for additional equipment, seriously affecting user experience and product competitiveness. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for replenishing power after the battery of an energy storage system is depleted, which can solve the power depletion problem without adding power replenishment equipment or disassembling the battery.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for replenishing power after battery depletion in an energy storage system includes: when battery depletion is detected, prohibiting battery charging and discharging; if a safety signal is received, resetting to restore battery charging and prohibiting discharging, configuring the battery to perform a first-stage charging at a preset low-rate charging current; if the individual cell voltage of the battery is greater than a first voltage threshold, stopping charging and allowing the battery to rest for a preset time; determining whether the individual cell voltage of the battery is stable after the preset rest time, and if so, performing a second-stage charging at a low-rate charging current until the individual cell voltage of the battery reaches a second voltage threshold, stopping charging and allowing the battery to rest, wherein the second voltage threshold is greater than the first voltage threshold; otherwise, returning to the step of performing the first-stage charging at a low-rate charging current.

[0005] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows: A power replenishment terminal for an energy storage system after battery depletion includes a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it performs the following steps: When a battery is detected to be low on power, charging and discharging are prohibited. If a safety signal is received, a reset is performed to restore battery charging and prohibit discharging. The battery is configured to perform a first-stage charging at a preset low-rate charging current. If the individual cell voltage of the battery is greater than a first voltage threshold, charging is stopped and the battery is left to stand for a preset time. It is then determined whether the individual cell voltage of the battery is stable after the preset time of rest. If it is, a second-stage charging at a low-rate charging current is performed until the individual cell voltage of the battery reaches a second voltage threshold, at which point charging is stopped and the battery is left to stand. The second voltage threshold is greater than the first voltage threshold. Otherwise, the process returns to the first-stage charging step with a low-rate charging current.

[0006] The beneficial effects of this invention are as follows: When a battery is detected to be depleted, the invention performs a system lock protection operation to prohibit battery charging and discharging, preventing misoperation and improving system safety; upon receiving a system reset command, the system is reset, allowing the battery to charge at a preset low-rate charging current while prohibiting discharging, avoiding damage to the depleted battery due to high-current charging and extending battery life; by charging the battery in the first stage at a preset low-rate charging current until the individual cell voltage exceeds a first voltage threshold, charging is stopped and the battery is left to stand, and then the stability of the individual cell voltage after standing is judged. If it is stable, a second stage of charging is performed at a preset low-rate charging current until the individual cell voltage exceeds a higher second voltage threshold, then charging is stopped and the battery is left to stand; if it is unstable, the first stage of charging is returned. This phased charging and standing monitoring mechanism ensures that the charging process is precise and controllable, improving the reliability and accuracy of battery recovery; compared with the traditional method of relying on external equipment to replenish the battery after it is depleted, this invention achieves replenishment through system integration, without the need for additional equipment, simplifying the operation process, saving costs, and without the need to disassemble the battery, improving the portability and efficiency of replenishment. Attached Figure Description

[0007] Figure 1 A flowchart illustrating the steps of a method for replenishing power after battery depletion in an energy storage system, as provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a power replenishment terminal for an energy storage system after battery power is depleted, provided in an embodiment of the present invention. Figure 3 This is the first part of a power replenishment logic flowchart of a power replenishment method for an energy storage system after battery depletion, provided in an embodiment of the present invention; Figure 4 This is the second part of the power replenishment logic flowchart of a power replenishment method for an energy storage system after battery depletion, provided in an embodiment of the present invention; Figure 5 The third part of the power replenishment logic flowchart of a power replenishment method for an energy storage system after battery depletion provided in an embodiment of the present invention; Figure 6 This is the first part of a second power replenishment logic flowchart of a power replenishment method for an energy storage system after battery depletion, provided in an embodiment of the present invention. Figure 7 This is the second part of a second power replenishment logic flowchart for a power replenishment method for an energy storage system after battery depletion, provided in an embodiment of the present invention. Detailed Implementation Definitions:

[0008] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0009] With the rapid development of the energy storage industry, various battery products are widely used in existing technologies. However, batteries generally suffer from performance degradation and capacity reduction after long-term use, which directly leads to devices being more prone to insufficient power or even battery depletion (i.e., excessive discharge below the cutoff voltage). Once a battery is depleted, it will trigger a series of serious consequences, including but not limited to permanent capacity decay, shortened cycle life, internal structural damage, increased risk of thermal runaway, and decreased reliability of the entire energy storage system. To prevent battery depletion, conventional technologies mainly rely on the Battery Management System (BMS) to monitor the battery status in real time, combined with regular charge-discharge maintenance to prevent over-discharge. However, these preventative measures cannot completely eliminate the occurrence of battery depletion. When battery depletion actually occurs, existing technologies usually require removing the depleted battery pack from the energy storage system and charging it separately using additional dedicated charging equipment. This method has significant drawbacks: the operation process is cumbersome, consumes a lot of time and manpower, the charging cost is high, and the portability is poor due to the need for additional equipment, seriously affecting user experience and product competitiveness.

[0010] To address the aforementioned issues, this invention provides a method for post-discharge power restoration that can be completed within the energy storage system, using mains power as the power source, without requiring the removal of the battery pack or additional power restoration equipment. This approach enables safe, convenient, and low-cost battery power restoration, significantly improving user experience and system reliability.

[0011] The following describes in detail a method for replenishing power after the battery of an energy storage system has been depleted, as detailed in the appendix. Figure 1 ,include: Step 101: When battery depletion is detected, battery charging and discharging are prohibited. Depletion refers to a state where the battery is not charging while charging is permitted but discharging is prohibited, and the individual cell voltage is below the fourth voltage threshold. Prohibiting battery charging and discharging refers to system lockout protection, locking the battery's charge / discharge control circuit and outputting a system lockout protection status signal. For example, a cell voltage below 2.0V is considered depletion.

[0012] Step 102: If a safety signal is received, a reset is performed to restore battery charging and prohibit discharge. The battery is then configured to undergo the first stage of charging at a preset low-rate charging current. Here, the safety signal indicates that there are no safety hazards at the energy storage system site. Reset refers to the operation of resetting the system state to allow charging and prohibiting discharge via dedicated software. The low-rate charging current refers to a charging current of 0.05C. The first stage of charging refers to charging the battery at a low-rate charging current until the individual cell voltage exceeds a first voltage threshold. For example, after confirming there are no safety or potential hazards at the site, a safety signal is sent, and the low-rate charging current is 0.05C.

[0013] Step 103: If the voltage of a single battery cell is greater than a first voltage threshold, then stop charging and allow the battery to rest for a preset time; where single cell voltage refers to the voltage of a single battery cell inside the battery. The first voltage threshold is 3.2V. The preset battery rest time refers to the set duration for which the battery remains in a state of neither charging nor discharging after charging is stopped. For example, the first voltage threshold is 3.2V.

[0014] Step 104: Determine whether the individual cell voltages of the battery are stable after a preset resting time. If so, perform a second-stage charging at a low-rate charging current until the individual cell voltages reach a second voltage threshold. Then, stop charging and allow the battery to rest. The second voltage threshold is greater than the first voltage threshold. Stability means that the variation in individual cell voltages is within a preset range. The second-stage charging refers to charging the battery at a low-rate charging current until the individual cell voltages reach the second voltage threshold. For example, the second voltage threshold is 3.65V.

[0015] Step 105, otherwise, return to the step of performing the first stage of charging the battery with a small charging current; As described above, the charging method provided in this embodiment effectively avoids the risk of thermal runaway or internal short circuits that may be caused by direct high-current charging after the battery is depleted, through multi-stage charging control and status monitoring. Specifically, charging and discharging are immediately prohibited when a depletion is detected, preventing further deterioration of the battery under fault conditions. After the safety signal is confirmed, only a preset low-rate current is allowed for the first stage of charging, limiting the initial charging power and reducing current surges. By monitoring the individual cell voltage to reach the first voltage threshold and then allowing it to stand still and judging voltage stability, it is possible to identify whether the battery has an internal short circuit or self-discharge abnormality; if the voltage is stable, it enters the second stage of charging to a higher voltage threshold, realizing gradual voltage recovery within the safety boundary. When the voltage is unstable, it returns to the first stage of charging, forming a closed-loop control, ensuring that the charging process can be interrupted and safely restarted under abnormal conditions. Thus, this embodiment achieves gentle and controllable recovery of depleted batteries, improves the safety and reliability of the charging process, and extends battery life. By charging in stages with small currents, damage to the battery is reduced, and by judging whether the individual cell voltage is stable in advance, problems can be identified in advance, reducing damage to the battery.

[0016] In one embodiment of this application, step 102, configuring the battery to perform a first-stage charging at a preset low-rate charging current, includes: Step 201: Turn on the power conversion system and charge the battery with a preset low-rate charging current through the power conversion system; where the power conversion system refers to the power conversion system, which is a device used to control the charging and discharging power of the battery.

[0017] Step 202: Monitor the individual cell voltage of the battery in real time. When the individual cell voltage is greater than the first voltage threshold, stop charging and let the battery rest for a preset time. As described above, this embodiment charges the battery with a preset low-rate charging current via an energy storage converter, effectively controlling current surges during charging and preventing excessive current from causing rapid changes in the internal active material structure or generating excessive heat. Real-time monitoring of the battery's individual cell voltage and stopping charging when it exceeds a first voltage threshold accurately determines the battery's charging state, preventing overcharging and protecting the battery's chemical stability and structural integrity. Subsequent resting of the battery for a preset time allows the ion concentration gradient inside the battery to moderate, resulting in a more uniform charge distribution on the electrode surfaces. This helps reduce battery polarization and improves efficiency and safety in subsequent charging stages. Therefore, this embodiment achieves gentle and controllable battery charging, extends battery cycle life, and improves the safety and reliability of the charging process.

[0018] In one embodiment of this application, step 104, determining whether the individual cell voltage of the battery is stable after a preset resting time, includes: Step 301: After a preset set time of rest, detect the change in the voltage of each individual cell of the battery. Step 302: If the change in the individual cell voltage is within a preset range, then the individual cell voltage is determined to be stable. Step 303: If the change in the individual cell voltage exceeds the preset range, the individual cell voltage is determined to be unstable. As described above, this embodiment provides a clear and quantifiable voltage stability judgment mechanism. By introducing a comparison step between the change amplitude and a preset range, subjective or vague stability judgments are transformed into objective, automated judgment processes based on preset thresholds. This directly improves the accuracy and reliability of battery voltage state monitoring and avoids operational errors caused by inconsistent judgment standards. Simultaneously, this mechanism is easy to integrate into a battery management system, automating and programming the judgment process, improving the efficiency and consistency of battery state assessment, and providing accurate and stable decision-making basis for subsequent battery operations.

[0019] In one embodiment of this application, step 104 involves charging the battery in a second stage with a low-rate charging current until the individual cell voltage of the battery reaches a second voltage threshold, after which charging is stopped and the battery is left to rest. Step 401: Turn on the energy storage converter and charge the battery with a preset low-rate charging current through the energy storage converter. Step 402: Monitor the individual cell voltage of the battery in real time. When the individual cell voltage is greater than the second voltage threshold, stop charging and let the battery rest. As described above, this embodiment achieves precise control over the final stage of battery charging by controlling the charging current rate and voltage threshold, avoiding battery performance degradation or safety hazards caused by overcharging, thereby improving the safety of the charging process and the battery's lifespan. Simultaneously, the resting phase helps to balance the internal charge distribution of the battery, further stabilizing the battery voltage state.

[0020] In one embodiment of this application, after step 104, where the battery is charged in a second stage at a low charging current until the individual cell voltage of the battery reaches a second voltage threshold, charging is stopped and the battery is left to rest, the process further includes: Step 501: Determine whether the individual cell voltage of the battery is stable after it has been left to stand. Step 502: If stable, perform a reset to restore battery charging and prevent discharge. Step 503: If unstable, return to the step of charging the battery in the second stage with a preset small charging current. As described above, this embodiment determines the subsequent operation process by judging the stability of the individual battery cell voltage after resting. Specifically, if the voltage is stable, a reset operation is performed to resume charging and prohibit discharge. This helps to safely continue the charging process under the premise that the battery state is reliable, avoiding the risks that may be caused by direct charging due to voltage fluctuations. If the voltage is unstable, the process returns to the step of using a preset low-rate charging current for the second stage of charging. This cyclic detection mechanism can continuously calibrate the charging state until the battery voltage reaches a stable condition. Thus, this embodiment achieves precise monitoring and adaptive adjustment of the battery charging end state, improves the safety and control accuracy of the charging process, effectively prevents overcharging, and optimizes the battery maintenance strategy.

[0021] In one embodiment of this application, step 101, detecting battery power loss, includes: Step 601: Real-time detection of individual cell voltages in the battery; Step 602: When the voltage of a single battery cell is detected to be lower than the third voltage threshold, battery discharge is prohibited and battery charging is allowed. The third voltage threshold is lower than the first voltage threshold. The third voltage threshold is 2.5V.

[0022] Step 603: In the state of prohibiting discharge and allowing charging, if the battery is not charged and the single cell voltage of the battery is detected to be lower than the fourth voltage threshold, it is determined that a power outage has occurred. The fourth voltage threshold is lower than the third voltage threshold. The fourth voltage threshold refers to 2.0V.

[0023] As described above, this embodiment effectively prevents the battery from entering a deep discharge state by real-time detection of the individual battery cell voltage and immediately prohibiting discharge and allowing only charging when the voltage drops below a third voltage threshold. Since the third voltage threshold is lower than the first voltage threshold, this design intervenes before the battery voltage drops to a lower protection threshold, providing earlier warning and protection. Furthermore, if charging is not initiated after entering the prohibited discharge state and the voltage continues to drop to a lower fourth voltage threshold, a deep discharge state is accurately determined. This tiered voltage threshold detection mechanism enables early identification and accurate determination of the battery's discharge state, thereby triggering subsequent protection or recovery processes in a timely manner, avoiding irreversible damage to the battery caused by excessively low voltage, and improving the reliability and safety of battery management.

[0024] In one embodiment of this application, it further includes: Step 701: When a battery power failure is detected, in response to a system lock command, battery charging and discharging are prohibited; Step 702: In response to the system reset command, the battery state is set to allow charging and disable discharging; As described above, this embodiment detects battery depletion and responds to system lock commands to prohibit charging and discharging. This allows for immediate disconnection of the charging and discharging circuit in case of battery abnormalities, preventing over-discharge or safety risks caused by battery depletion. Responding to system reset commands sets the battery state to allow charging and prohibits discharging, ensuring safe charging of the battery after system recovery while avoiding secondary faults that may be caused by immediate discharge. This process achieves precise control of the battery state, improving the safety and reliability of the system under abnormal conditions, and providing a clear state switching mechanism for subsequent recovery operations.

[0025] In one embodiment of this application, step 102, if a safety signal is received, involves resetting the battery to resume charging and prevent discharging, including: Step 801: If a safety signal indicating no safety hazards are received at the energy storage system site, battery charging is permitted and discharging is prohibited; As described above, this embodiment achieves precise and reliable control of the battery's charging and discharging state by introducing a safety signal as a reset condition. This avoids resuming the discharge function before safety hazards are eliminated, thereby improving the operational safety and management reliability of the energy storage system. Simultaneously, this mechanism simplifies the reset process, enabling the system to respond quickly to changes in safety status, thus improving the automation level and response efficiency of battery management.

[0026] In one embodiment of this application, step 101, prohibiting battery charging and discharging, includes: Step 901: Lock the battery's charge / discharge control circuit and output a system lock protection status signal; As described above, this embodiment locks the battery's charge / discharge control circuit, directly cutting off the battery's charge / discharge path at the hardware level, thereby forcibly prohibiting the battery's charging and discharging behavior. Simultaneously, it outputs a system lock protection status signal, providing a clear status indication to the battery management system or host computer, enabling the system to accurately and in real-time know that the battery has entered a locked protection state. This mechanism not only effectively prevents the battery from continuing to operate under abnormal or dangerous conditions, improving system safety, but also facilitates subsequent fault diagnosis, status monitoring, or system linkage through the output of the status signal, enhancing the controllability and reliability of the entire battery management system.

[0027] Please refer to Figure 2 The present invention also provides a power replenishment terminal 200 for an energy storage system after battery depletion, including a memory 201, a processor 202, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the various steps of the power replenishment method for an energy storage system after battery depletion as described above.

[0028] The beneficial effects of the terminal of the present invention are the same as those of the method described above, and will not be repeated here.

[0029] The above-mentioned method and terminal for replenishing power after the battery of the energy storage system is depleted can be applied to battery replenishment, especially for electric vehicle batteries. The following is a description of specific embodiments.

[0030] Reference Figure 3 , Figure 4 , Figure 5 The whole is a flowchart of the various parts. Figure 3 This is the first part. Figure 4 This is the second part. Figure 5 This is the third part.

[0031] Embodiment 1 of the present invention is as follows: Step A: System startup, acquiring the maximum power Pt of the front-end transformer of the energy storage system, the real-time power Pc of the customer's AC load, the power Pm collected by the AC meter, the real-time power Pa of the PCS, the real-time charging and discharging power Pb of the energy storage battery, and the charging request power Pv of the electric vehicle.

[0032] Step B: Determine if it is off-peak time. If so, prioritize using mains power and further determine if the battery SOC is greater than or equal to the set SOC. If the battery SOC is greater than or equal to the set SOC, it indicates that the battery has sufficient charge. At this point, determine if any vehicles are charging. If so, further determine if the electric vehicle's charging request power Pv is greater than the sum of the transformer's remaining power and the real-time charging and discharging power of the energy storage battery, i.e., Pt-(Pm-Pa)+Pb. If Pv is greater than Pt-(Pm-Pa)+Pb, then the output electric vehicle charging power is Pt-(Pm-Pa)+Pb; if Pv is less than or equal to Pt-(Pm-Pa)... If the battery SOC is +Pb, the output electric vehicle charging power is Pv. If the battery SOC is less than the set SOC, it means that the battery power is insufficient. At this time, it is determined whether there is a vehicle charging. If there is a vehicle charging, it is determined whether Pv is greater than the transformer's remaining power Pt-(Pm-Pa). If Pv is greater than Pt-(Pm-Pa), the output electric vehicle charging power is Pt-(Pm-Pa). If Pv is less than or equal to Pt-(Pm-Pa), the output electric vehicle charging power is Pv, and the remaining power Pt-(Pm-Pa)-Pv is used to charge the energy storage battery. If there is no vehicle charging, the output power Pt-(Pm-Pa) is used to charge the energy storage battery.

[0033] Step C: If the current time is not a valley period, determine if the current time is a peak period. If it is a peak period, prioritize using battery power and further determine if the battery SOC is greater than or equal to the set SOC: If the battery SOC is greater than or equal to the set SOC, it means the battery power is sufficient. At this time, determine if there is a vehicle charging. If there is a vehicle charging, determine if Pv is greater than Pb. If Pv is greater than Pb, output the electric vehicle charging power as Pb. If Pv is less than or equal to Pb, output the electric vehicle charging power as Pv. If there is no vehicle charging, determine if Pb is greater than or equal to Pm-Pa. If Pb is greater than or equal to Pm-Pa, ... The battery discharges to the customer load according to the power of Pm-Pa. If Pb is less than Pm-Pa, the battery discharges to the customer load according to the power of Pb, and the remaining power is output by the transformer. If the battery SOC is less than the set SOC, it means that the battery power is insufficient. At this time, it is determined whether there is a vehicle charging. If there is a vehicle charging, it is determined whether Pv is greater than Pt-(Pm-Pa). If Pv is greater than Pt-(Pm-Pa), the electric vehicle charging power is output as Pt-(Pm-Pa). If Pv is less than or equal to Pt-(Pm-Pa), the electric vehicle charging power is output as Pv. If there is no vehicle charging, the battery is not charged.

[0034] Step D: If the current time is not peak, determine if it is a normal time. If it is a normal time, select between battery power or AC power based on the battery status, and further determine if the battery SOC is greater than or equal to the set SOC: If the battery SOC is greater than or equal to the set SOC, it means the battery power is sufficient, and battery power is used first. At this time, determine if there is a vehicle charging. If there is a vehicle charging, determine if Pv is greater than Pb. If Pv is greater than Pb, output the electric vehicle charging power as Pb; if Pv is less than or equal to Pb, output the electric vehicle charging power as Pv. If there is no vehicle charging, determine if Pb is greater than or equal to Pm-Pa. If Pb is greater than or equal to Pm-Pa, ... The power output is Pm-Pa to the customer load. If Pb is less than Pm-Pa, the power output is Pb to the customer load, and the remaining power is output by the transformer. If the battery SOC is less than the set SOC, it means that the battery power is insufficient. At this time, the mains power is used to determine whether there is a vehicle charging. If there is a vehicle charging, it is determined whether Pv is greater than Pt-(Pm-Pa). If Pv is greater than Pt-(Pm-Pa), the electric vehicle charging power is Pt-(Pm-Pa). If Pv is less than or equal to Pt-(Pm-Pa), the electric vehicle charging power is Pv. If there is no vehicle charging, the power output is Pt-(Pm-Pa) to charge the energy storage battery.

[0035] Step E: During peak hours or normal battery discharge, monitor in real time whether the power Pm collected by the AC meter is less than 0 for 10 seconds. If Pm is less than 0 for 10 seconds, a reverse current fault is determined to have occurred, a reverse current fault is reported, and the discharge is stopped.

[0036] Reference Figure 6 , Figure 7 The whole is a flowchart of the various parts. Figure 6 This is the first part. Figure 7 This is the second part. Embodiment two of the present invention is as follows: Step A: The system is running normally.

[0037] Step B: The BMS determines in real time whether the individual cell voltage is too low.

[0038] Step C: Determine if the individual cell voltage is less than 2.5V. If the result is no, the system will stop operating if the individual cell voltage is too low; if the result is yes, then... Loop to check if the individual cell voltage is less than 2.5V. Step D: Under the state of prohibiting discharge and allowing charging, determine whether to charge. If charging, determine whether the individual cell voltage is greater than 2.5V. If the individual cell voltage is greater than 2.5V, return to BMS to determine whether the individual cell voltage is less than 2.5V in real time.

[0039] Step E: If not charging, determine if the individual cell voltage is less than 2.0V. If the individual cell voltage is less than 2.0V, it is determined that the individual cell voltage is seriously too low and power loss has occurred.

[0040] Step F: System lock protection, prohibiting charging and discharging. This corresponds to step 101 above.

[0041] Step G: Determine if there are any other safety or potential hazards at the site. If there are no other safety or potential hazards at the site, reset the system using dedicated software. Step H: If there are other safety or potential hazards on site, determine whether the hazards have been eliminated. If the hazards have been eliminated, reset the system using dedicated software. If the hazards have not been eliminated, return to the manual intervention step.

[0042] Step I: After resetting the system using dedicated software, allow low-current charging but prohibit discharging. This corresponds to step 102 above.

[0043] Step J: Turn on the PCS and charge the system with a small current of 0.05C.

[0044] Step K: Determine if the individual cell voltage is greater than 3.2V. If the individual cell voltage is greater than 3.2V, stop charging and let it stand. If the individual cell voltage is not greater than 3.2V, return to the step of turning on the PCS to charge the system with a small current of 0.05C. This corresponds to step 103 above.

[0045] Step L: After resting, determine whether the individual cell voltage is stable. If the individual cell voltage is stable, turn on the PCS and charge the system with a small current of 0.05C. If the individual cell voltage is unstable, return to the step of turning on the PCS and charging the system with a small current of 0.05C. This corresponds to step 104 above.

[0046] Step M: After restarting the PCS to charge the system with a small current of 0.05C, determine whether the individual cell voltage is greater than 3.65V. If the individual cell voltage is greater than 3.65V, stop charging and let it stand. This corresponds to step 104 above.

[0047] Step N: After resting, determine if the individual cell voltage is stable. If the individual cell voltage is stable, stop charging; the system is normal. If the individual cell voltage is unstable, return to the step of turning on the PCS to charge the system with a small current of 0.05C. This corresponds to step 105 above.

[0048] Step 0: The system lock is removed, and the system returns to normal operation.

[0049] In summary, this invention performs a system lock protection operation when battery depletion is detected to prohibit battery charging and discharging, preventing misoperation and improving system safety. Upon receiving a system reset command, it resets the system and allows the battery to charge at a preset low-rate charging current while prohibiting discharging, preventing damage to the depleted battery due to high-current charging and extending battery life. The invention performs a first-stage charging of the battery at a preset low-rate charging current until the individual cell voltage exceeds a first voltage threshold, then stops charging and allows the battery to rest. The stability of the individual cell voltage after resting is then assessed. If stable, a second-stage charging at a preset low-rate charging current is performed until the individual cell voltage exceeds a higher second voltage threshold, then charging is stopped and the battery is allowed to rest. If unstable, the process returns to the first-stage charging. This phased charging and resting monitoring mechanism ensures precise and controllable charging, improving the reliability and accuracy of battery recovery. Compared to traditional methods that require external equipment for recharging after battery depletion, this invention achieves recharging through system integration, eliminating the need for additional equipment, simplifying the operation process, saving costs, and improving the portability and efficiency of recharging.

[0050] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for replenishing power after battery depletion in an energy storage system, characterized in that, The methods include: When a battery drain is detected, charging and discharging of the battery are prohibited. If a safety signal is received, a reset is performed to restore the charging of the battery and prevent discharge. The battery is then configured to perform the first stage of charging at a preset low-rate charging current. If the voltage of a single cell of the battery is greater than a first voltage threshold, charging is stopped and the battery is left to stand for a preset time. Determine whether the individual cell voltage of the battery is stable after a preset resting time. If so, charge the battery in the second stage with the low-rate charging current until the individual cell voltage of the battery reaches the second voltage threshold, then stop charging and let the battery rest. The second voltage threshold is greater than the first voltage threshold. Otherwise, return to the step of charging the battery in the first stage with the low-rate charging current.

2. The method according to claim 1, characterized in that, The configuration of the battery to perform a first-stage charging at a preset low-rate charging current includes: Turn on the energy storage converter and charge the battery with the preset low-rate charging current through the energy storage converter; The individual cell voltage of the battery is monitored in real time. When the individual cell voltage is greater than the first voltage threshold, charging is stopped and the battery is left to stand for a preset time.

3. The method according to claim 1, characterized in that, The step of determining whether the individual cell voltage of the battery is stable after a preset resting time includes: After a preset resting time, the change in the voltage of each individual cell of the battery is detected; If the change in the voltage of the individual cell is within a preset range, then the voltage of the individual cell is determined to be stable. If the change in the voltage of a single cell exceeds a preset range, the voltage of the single cell is determined to be unstable.

4. The method according to claim 1, characterized in that, The second stage of charging the battery with the low-rate charging current until the individual cell voltage of the battery reaches the second voltage threshold, then stopping charging and allowing it to rest, includes: Turn on the energy storage converter and charge the battery with the preset low-rate charging current through the energy storage converter; The individual cell voltage of the battery is monitored in real time. When the individual cell voltage exceeds a second voltage threshold, charging is stopped and the battery is left to stand still.

5. The method according to claim 1, characterized in that, After the second stage of charging the battery with the low-rate charging current until the individual cell voltage of the battery reaches the second voltage threshold, the charging is stopped and the battery is left to rest, the process further includes: Determine whether the individual cell voltages of the battery are stable after it has been left to stand. If stable, a reset is performed to restore the battery's charging and prevent discharge. If the charging is unstable, return to the step of charging the battery in the second stage at the preset low-rate charging current.

6. The method according to claim 1, characterized in that, The detection of battery power loss includes: Real-time monitoring of the individual cell voltages of the battery; When the voltage of a single cell of the battery is detected to be lower than a third voltage threshold, the battery is prohibited from discharging and the battery is allowed to charge, wherein the third voltage threshold is lower than the first voltage threshold; If the battery is not charged and the voltage of a single cell of the battery is detected to be lower than a fourth voltage threshold when the state of discharging is prohibited and charging is permitted, it is determined that a power outage has occurred. The fourth voltage threshold is lower than the third voltage threshold.

7. The method according to claim 1, characterized in that, Also includes: When a battery drain is detected, the system locks the battery to prevent charging and discharging in response to a system lock command. In response to the system reset command, the battery state is set to allow charging and disable discharging.

8. The method according to claim 1, characterized in that, The step of resetting the battery to resume charging and prevent discharge upon receiving a safety signal includes: If a safety signal indicating no safety hazards are received at the site of the energy storage system, the battery is allowed to charge and discharging is prohibited.

9. The method according to claim 1, characterized in that, The prohibition of charging and discharging the battery includes: The charging and discharging control circuit of the battery is locked and a system lock protection status signal is output.

10. A power replenishment terminal for an energy storage system after battery depletion, characterized in that, The terminal includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method as described in any one of claims 1 to 9.

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