Energy storage system upgrade method and apparatus

Abstract

The application belongs to the technical field of energy storage and relates to an energy storage system upgrading method and device. The method comprises the following steps: in the case that the energy storage system is in an active state, in response to an upgrading instruction, obtaining running state data of the energy storage system, according to the running state data, controlling the output power of each energy branch in the energy storage system to decrease at a preset change rate according to a preset energy branch control sequence, so that the energy storage system is transitioned from the active state to a stationary state, and in the case that it is determined that the energy storage system is in the stationary state, upgrading the energy storage system. After the energy storage system is upgraded, according to the running state data obtained before the upgrading, the target running state of the energy storage system is determined, and the output power of each energy branch in the energy storage system is controlled to recover to the target running state according to a preset energy branch recovery sequence. The electrical loss risk of core power devices is eliminated, and in combination with the running state data before the upgrading, high safety, manual intervention-free and inductive continuous online upgrading are realized.

Description

Technical Field

[0001] This invention belongs to the field of energy storage technology and relates to a method and apparatus for upgrading an energy storage system. Background Technology

[0002] Software upgrades for energy storage systems (such as residential energy storage cabinets and commercial / industrial energy storage systems) are a critical aspect of their entire lifecycle management, directly impacting their long-term stable operation. However, current energy storage system upgrades often employ direct shutdowns or simple power outages, occurring during normal system operation, especially high-power charging and discharging. This presents numerous technical risks and safety hazards: voltage / current spikes can easily impact power devices, causing relay arcing and other electrical shocks that damage hardware; upgrades consume controller resources, potentially leading to control loop interruptions and protection function failures, resulting in data security and system stability issues; and the abrupt interruption of charging and discharging strategies causes economic losses for users. Furthermore, after an upgrade, the operating mode must be manually reset, making seamless transition from previous tasks impossible. Existing methods cannot avoid these risks and fail to meet the requirements for safe, efficient, and continuous upgrades of energy storage systems. A scientific upgrade method is urgently needed to address these pain points. Summary of the Invention

[0003] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a method for upgrading energy storage systems.

[0004] The objective of this invention can be achieved through the following technical solution: a method for upgrading an energy storage system, comprising: When the energy storage system is in operation, in response to the upgrade command, the system acquires the operating status data of the energy storage system; the operating status indicates that the energy storage system is in normal operation and there is power flow, and the operating status data includes the output power of the photovoltaic branch and the output power of the power conversion system. Based on the operating status data, the photovoltaic controller controls the output power of the photovoltaic branch to decrease to zero at a first preset slope. After the output power of the photovoltaic branch drops to zero, the charging and discharging power between the energy storage system and the grid or load is controlled by the power conversion system to drop to zero according to the second preset slope. If the energy storage system is determined to be in a quiescent state, upgrade the energy storage system; the quiescent state indicates that the energy storage system is powered on but there is no power conversion between the energy storage system and the external power grid or load.

[0005] As an optional embodiment of the present invention, if the energy storage system further includes distributed energy branches other than the photovoltaic branch, then after the output power of the photovoltaic branch decreases to zero and before the power conversion system begins to reduce the charging and discharging power, the system further includes: The controller corresponding to the distributed energy branch controls the output power of the distributed energy branch to decrease to zero according to the corresponding preset power reduction slope.

[0006] As an optional embodiment of the present invention, if the absolute value of the real-time total charging and discharging current of the energy storage system battery pack is less than or equal to the preset current safety value within the preset power adjustment time, the energy storage system is upgraded. If the absolute value of the total real-time charging and discharging current exceeds the preset current safety value, the energy storage system will be shut down, and the energy storage system will be upgraded after completion.

[0007] As an optional embodiment of the present invention, the upgrade command further includes a delayed upgrade command, wherein, in response to the delayed upgrade command, the energy storage system is upgraded, including: Download the upgrade package required for the energy storage system upgrade; Real-time monitoring of the total charging and discharging current of the energy storage system's battery pack; If the absolute value of the total real-time charging and discharging current is less than or equal to the preset current safety value for a duration that is greater than or equal to the preset continuous time, the energy storage system is determined to be in a static state, and the upgrade package has been downloaded, then the energy storage system is upgraded.

[0008] As an optional embodiment of the present invention, it further includes: After the energy storage system is upgraded, the target operating status of the energy storage system is determined based on the operating status data obtained before the upgrade. According to the preset energy branch restoration sequence, the output power of each energy branch in the energy storage system is controlled to restore to the target operating state.

[0009] As an optional embodiment of the present invention, if the target operating state is an active state, the output power of each energy branch in the energy storage system is controlled to be restored to the target operating state according to a preset energy branch restoration sequence, including: The output power of the photovoltaic branch and the output power of the power conversion system before the energy storage system upgrade are obtained based on the operating status data. During the preset zero-power maintenance time, the output power of each energy branch is controlled to remain at zero; The photovoltaic controller controls the output power of the photovoltaic branch to be restored to the power when responding to the upgrade command according to the third preset slope. After the output power of the photovoltaic branch is restored to the power at the time of responding to the upgrade command, the charging and discharging power between the energy storage system and the grid or load is controlled by the power conversion system to be restored to the power at the time of responding to the upgrade command according to the fourth preset slope.

[0010] As an optional embodiment of the present invention, if the energy storage system is also connected to distributed energy branches other than the photovoltaic branch, and the output power of the distributed energy branches when the energy storage system responds to the upgrade command is obtained based on the operating status data, then after the output power of the photovoltaic branch recovers to the power at the time of responding to the upgrade command, and before the power conversion system starts to restore the charging and discharging power, the following method is further included: The controller corresponding to the distributed energy branch controls the output power of the distributed energy branch to be restored to the power at the time of responding to the upgrade command according to the corresponding preset power recovery slope.

[0011] As an optional embodiment of the present invention, it further includes: If the target operating state is standby, the upgraded energy storage system will remain in standby state.

[0012] The present invention also proposes an energy storage system upgrade device, comprising: The first unit is used to obtain the operating status data of the energy storage system in response to the upgrade command when the energy storage system is in operation. The operating status indicates that the energy storage system is in normal operation and there is power flow. The operating status data includes the output power of the photovoltaic branch and the output power of the power conversion system. The second unit is used to control the output power of the photovoltaic branch to decrease to zero at a first preset slope according to the operating status data through the photovoltaic controller. The third unit is used to control the charging and discharging power between the energy storage system and the grid or load to decrease to zero at a second preset slope after the output power of the photovoltaic branch decreases to zero through the power conversion system. The fourth unit is used to upgrade the energy storage system when it is determined that the energy storage system is in a quiescent state; the quiescent state indicates that the energy storage system is powered on but there is no power conversion between the energy storage system and the external power grid or load.

[0013] As an optional embodiment of the present invention, it further includes: The fifth unit is used to determine the target operating status of the energy storage system after the upgrade is completed, based on the operating status data obtained before the upgrade. The sixth unit is used to control the output power of each energy branch in the energy storage system to be restored to the target operating state according to the preset energy branch restoration sequence.

[0014] The present invention also provides an electronic device, comprising: processor; Memory used to store processor-executable instructions; The processor is configured to implement the aforementioned energy storage system upgrade method when executing executable instructions.

[0015] Compared with the prior art, the present invention has the following technical effects: 1) According to the preset energy branch control sequence, the output power of each energy branch is controlled to decrease slowly, realizing a smooth transition from an active state to a static state for the multi-source heterogeneous energy storage system. This avoids the large jump in electrical energy caused by direct shutdown in existing technologies. During the process of reducing output power, the power conversion system plays a core role, fundamentally eliminating the physical hazards of arcing and voltage / current spikes breaking down semiconductor devices.

[0016] 2) By using a preset current safety value as a hard safety indicator and asynchronously downloading the upgrade package and monitoring it over a continuous time window in the background, the risk of control loop interruption, crashes, or system loss of control caused by control logic errors is avoided. On the other hand, the upgrade operation is performed during the natural idle time of the energy storage system, minimizing the interference of the upgrade process on the user's charging and discharging tasks and economic benefits.

[0017] 3) After the energy storage system is upgraded and restarted, it is initialized after a preset zero-power maintenance time, and then the output power of each energy branch is restored smoothly according to the preset energy branch restoration sequence. This eliminates the cumbersome manual reconfiguration required after the energy storage upgrade in the existing technology, and ensures the seamless and continuous operation of the energy storage system after the upgrade. Attached Figure Description

[0018] Figure 1 This is a flowchart of an energy storage system upgrade method according to an embodiment of the present invention; Figure 2 This is a block diagram of an energy storage system upgrade device according to an embodiment of the present invention. Detailed Implementation

[0019] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments.

[0020] The energy storage system in this embodiment consists of an energy storage battery pack, a battery management system (BMS), a power conversion system (PCS), a main control unit, and multi-source auxiliary access branches. The most vulnerable and sensitive electrochemical energy source, the energy storage battery pack, has its DC output electrically coupled to the DC side of the power conversion system via physical closing devices such as DC circuit breakers. The AC side of the power conversion system is connected to the power grid or load to achieve bidirectional energy conversion. Simultaneously, multi-source auxiliary access branches (such as photovoltaic branches and distributed energy branches) are energy coupled to the energy storage battery pack via a bus. For communication and control, each device establishes a bidirectional communication link based on a CAN / RS485 bus or industrial Ethernet. The battery management system collects battery pack data in real time, and after digital filtering and noise reduction, uploads the actual battery physical parameters to the main control unit. The main control unit, acting as the global coordinating brain, monitors the system status in real time through the communication link, issues power adjustment commands to the power conversion system and each auxiliary branch controller, and controls the opening and closing of physical closing devices during upgrades or anomalies, thereby providing reliable data support and a stable control loop during hardware and software upgrades.

[0021] Example 1 Based on the technical problems highlighted in the background, this embodiment proposes an energy storage system upgrade method, such as... Figure 1 As shown, it includes: When the energy storage system is in an active state, it responds to upgrade commands and acquires the operating status data of the energy storage system; Based on the operating status data, and in accordance with the preset energy branch control sequence, the output power of each energy branch in the energy storage system is controlled to decrease according to the preset rate of change, so that the energy storage system transitions from an active state to a static state. If the energy storage system is determined to be in a quiescent state, upgrade the energy storage system.

[0022] To achieve safe and efficient upgrades of energy storage systems while they are in operation, this embodiment acquires operational status data of the energy storage system when it is in an active state and responds to upgrade commands. This data is then used to smoothly transition the energy storage system from an active state to a static state, eliminating the risk of electrical shocks. The operational state indicates that the energy storage system is functioning normally and experiencing power flow, including but not limited to the following: the energy storage system is performing charging, discharging, or grid ancillary services (such as frequency regulation and peak shaving), or is in power regulation mode. In contrast to the active state, the static state indicates that although the energy storage system is powered on, the power conversion system has stopped energy conversion. There is no power conversion between the energy storage system and the external grid or load; that is, the charging and discharging power between the energy storage system and the external grid or load is zero or within a preset safe power threshold range. In this state, the energy storage system is in a safe condition suitable for upgrade operations.

[0023] When the energy storage system is active, in response to a user-requested upgrade command, the system immediately records operational status data such as target power, energy source, and operating mode. The energy source includes energy branches and their corresponding power data. Different energy branches (such as photovoltaic branches, distributed energy branches, and power conversion systems) play different roles in the energy storage system. Therefore, this embodiment controls each energy branch sequentially according to its energy source and a preset control sequence to address system-level safety issues related to energy flow. The preset energy branch control sequence ensures that the energy flow within the energy storage system is reasonable and controlled during power reduction, guaranteeing the electrical safety of the overall system architecture. Furthermore, the output power of each energy branch is reduced at a preset rate of change to address the physical impact of rapid energy reduction. By gradually reducing power at a preset rate of change, dynamic electrical risks at the component level are mitigated, significantly extending hardware lifespan and preventing step-like load disturbances from the external power grid.

[0024] This embodiment combines a preset energy branch control sequence with a preset rate of change for each energy branch. The preset energy branch control sequence determines the safe direction of energy flow, while the preset rate of change determines the physical rate of energy decay. If there is only a control sequence without a gradual reduction, although the energy flow is correct, local abrupt changes can still cause electrical risks such as device arcing and grid oscillations. If there is only a gradual reduction without a reasonable control sequence, although the output power decreases slowly, an unreasonable control sequence can lead to risks such as bus voltage overload. This embodiment combines the two to ensure that throughout the entire power reduction transition process, each energy branch and at each power reduction point in time, the energy storage system is in a dual controllable state of "correct energy flow and a gentle power decrease rate," achieving a lossless, imperceptible, and safe transition from an active state to a static state, laying a solid safety foundation for subsequent upgrades.

[0025] Preferably, the operating status data includes the output power of the photovoltaic branch and the output power of the power conversion system. According to a preset energy branch control sequence, the output power of each energy branch within the energy storage system is controlled to decrease at a preset rate of change, including: The photovoltaic controller controls the output power of the photovoltaic branch to decrease to zero at a first preset slope. After the output power of the photovoltaic branch drops to zero, the charging and discharging power between the energy storage system and the grid or load is controlled by the power conversion system to drop to zero according to the second preset slope.

[0026] When the energy branch includes a photovoltaic (PV) branch and a power conversion system, the acquired operating status data includes the output power of the PV branch and the output power of the power conversion system. In this case, the preset control sequence for the energy branch is to first control the PV branch to reduce its output power, and then control the power conversion system to reduce its output power.

[0027] Specifically, the photovoltaic branch is first controlled to reduce its output power. This means that the photovoltaic controller corresponding to the photovoltaic branch controls the output power of the photovoltaic branch to gradually decrease to zero according to the first preset slope. Then, the power conversion system is controlled to reduce its output power. Specifically, the power conversion system controls the charging and discharging power between the energy storage system and the external power grid or load to gradually decrease to zero according to the second preset slope.

[0028] This is because the photovoltaic branch continuously inputs electrical energy into the DC bus of the energy storage system while it is operating, thus acting as an energy source. The power conversion system is the core channel for discharging and balancing energy from the DC bus to the AC grid or load. By prioritizing the reduction of the photovoltaic branch's output power to zero, the continuous input of external active power to the DC bus is cut off at the source. During this process, the power conversion system continues to operate, continuing to dissipate energy and balance the load. This effectively avoids the phenomenon of energy accumulation on the DC bus caused by the photovoltaic branch continuing to input electrical energy while the power conversion system is prioritized to be shut down. It also completely avoids serious electrical faults such as capacitor breakdown, DC switch burnout, or insulation damage caused by a sudden surge in DC bus voltage, fundamentally ensuring the physical and electrical safety of the DC side.

[0029] Specifically, during the dynamic transition period of reduced photovoltaic output power, the energy storage system is susceptible to fluctuations in light intensity or control disturbances. During this process, the power conversion system that maintains normal operation can dynamically adjust its own output charging and discharging power in real time to dynamically offset the transient fluctuations during the reduction of photovoltaic output power. This ensures that the DC bus voltage and the output frequency of the energy storage system remain in stable closed-loop control throughout the entire transition process of reducing large power disturbances, effectively preventing oscillations or misalignments in the control system.

[0030] Once the output power of the photovoltaic branch has completely returned to zero, it indicates that the energy source on the DC side of the energy storage system has been safely disconnected. At this point, the output power of the power conversion system is then reduced to zero. Under this control sequence, the power conversion system essentially performs a shutdown operation under excellent electrical conditions of passive input, no load, or extremely light load. This greatly limits the transient electrical stress impact that power semiconductor devices and other electronic components experience at the moment of shutdown, thereby significantly extending the physical service life of the core electrical components in the power conversion system.

[0031] It should be noted that the first and second preset slopes can be either fixed constants that remain constant during a single power reduction process, or they can be changing slopes that are adaptively adjusted in real time according to the operating status of the energy storage system during the power reduction process. Specifically, the first and second preset slopes can be set once before the power reduction starts, based on the historical operating conditions of the energy storage system. Alternatively, during the power reduction process, real-time feedback parameters such as the DC bus voltage change rate, grid voltage / frequency fluctuation amplitude, equipment temperature rise rate, or real-time illumination change rate can be acquired and used to perform real-time closed-loop correction and adaptive adjustment of the first and second preset slopes. This results in the slope curve exhibiting piecewise linear or nonlinear changes, ensuring that the power change process achieves optimal dynamic adaptation with the current physical conditions of the power grid and equipment.

[0032] Preferably, if the energy storage system also includes distributed energy branches other than the photovoltaic branch, then after the output power of the photovoltaic branch drops to zero and before the power conversion system starts to reduce the charging and discharging power, it also includes: The controller corresponding to the distributed energy branch controls the output power of the distributed energy branch to decrease to zero according to the corresponding preset power reduction slope.

[0033] When the energy branch includes distributed energy branches in addition to photovoltaic (PV) branches and power conversion systems, the acquired operating status data includes the output power of the PV branches, the output power of the power conversion systems, and the output power of the distributed energy branches. In this case, the corresponding preset energy branch control sequence is: first, control the PV branches to reduce their output power; then, control the distributed energy branches to reduce their corresponding output power; and finally, control the power conversion systems to reduce their output power. Specifically, controlling the distributed energy branches to reduce their corresponding output power means controlling the distributed energy branch's output power to gradually decrease to zero according to a preset power reduction slope and gradient, using the controller corresponding to that distributed energy branch.

[0034] Furthermore, when multiple distributed energy branches are connected to the energy storage system (e.g., simultaneously connected to photovoltaic, wind power, fuel cell, or diesel power branches, with multiple distributed energy branches jointly supplying power to the DC bus), the power reduction control sequence among the distributed energy branches, as well as the corresponding power reduction slope for each distributed energy branch, can be flexibly set according to the actual operating conditions and the physical characteristics of the equipment itself. For example, after the energy storage system responds to a power reduction command, it can prioritize reducing the power of the distributed energy branch that has the greatest impact on DC voltage fluctuations, or prioritize reducing the power of the distributed energy branch with the fastest dynamic response speed and the lowest mechanical inertia, thereby achieving a smooth and gentle shutdown of multiple heterogeneous sources.

[0035] More importantly, in the overall control chain containing one or more distributed energy branches, the photovoltaic (PV) branch must be the highest priority response branch during the entire power reduction process. This is because the PV branch has strong randomness, no physical inertia, and directly inputs electrical energy to the DC bus. If it is not shut down first, transient electrical stress impacts caused by light fluctuations or control disturbances will directly affect the safety of the entire energy storage system. Correspondingly, the power conversion system must be the last link in the entire power reduction process to perform the shutdown operation. This is because the power conversion system plays a role in actively discharging energy, dynamically balancing, and suppressing energy accumulation on the DC bus of the energy storage system. Before the output power of the PV branch and all other distributed energy branches is safely reduced to zero, there is still a continuous flow of energy injected into the DC side. Under these circumstances, it is necessary to ensure that the power conversion system is in normal working condition to continue to play a closed-loop regulation role in discharging energy and stabilizing the DC bus voltage. Once it is confirmed that the output power of the photovoltaic branch and the output power of all other distributed energy branches have been reduced to zero and there is no energy injection on the DC side, the charging and discharging power of the power conversion system can be reduced to zero and a shutdown can be executed.

[0036] Preferably, when the energy storage system is determined to be in a quiescent state, upgrading the energy storage system includes: If the absolute value of the total real-time charging and discharging current of the energy storage system battery pack is less than or equal to the preset current safety value within the preset power adjustment time, the energy storage system will be upgraded. If the absolute value of the total real-time charging and discharging current exceeds the preset current safety value, the energy storage system will be shut down, and the energy storage system will be upgraded after completion.

[0037] Since the battery pack of an energy storage system is the final convergence node for the interaction and physical aggregation of various energy sources within the system, and is also an electrochemical entity extremely sensitive to overcurrent and temperature rise, making it the most critical yet most vulnerable component of the energy storage system, this embodiment uses preset power adjustment times and preset current safety values ​​to monitor in real time the absolute value change of the total real-time charging and discharging current of the battery pack as the output power of each energy branch within the energy storage system decreases according to a preset rate of change. It should be noted that the real-time total charging and discharging current is obtained by the battery management system acquiring the raw current signal and processing it using digital waveform filtering algorithms (such as moving average filtering or low-pass filtering algorithms) to remove high-frequency switching interference and sensor glitches, thus obtaining the true effective value of the physical current and avoiding transient false triggering caused by noise.

[0038] If, within a preset power adjustment time (e.g., 5 seconds), the absolute value of the total real-time charging and discharging current of the energy storage system's battery pack is less than or equal to a preset current safety value, it indicates that the energy storage system is in a quasi-static electrical state. At this point, an upgrade operation is performed on the energy storage system, including core operations such as firmware erasure, burning, and verification. It should be noted that using absolute values ​​as the criterion filters out complex charging and discharging direction vector calculations, preventing direction judgment delays caused by frequent switching of charging and discharging states under complex microgrid conditions, thereby significantly improving the protection response speed of the overall control chain. Furthermore, the preset power adjustment time can be set based on the adaptability of historical power changes to the corresponding grid and equipment physical conditions; the preset current safety value can be set based on the electrical environment stability required for performing live upgrade operations.

[0039] Conversely, if the absolute value of the real-time total charging and discharging current of the energy storage system's battery pack suddenly exceeds the preset current safety value within the preset power adjustment time, or if the absolute value of the real-time total charging and discharging current still exceeds the preset current safety value after the preset power adjustment time has ended, it indicates that a severe short circuit or internal electronic component breakdown has occurred outside the energy storage system during the gradual power reduction control process. In this case, the gradual slope control may fail or react lags, and the energy storage system faces a serious electrical risk of losing control. Therefore, the highest level of safety protection must be implemented, disconnecting the main controller through cascading protection, forcibly shutting down the external energy input flow of each energy branch, and shutting down the power conversion system to perform an emergency shutdown operation on the energy storage system. Only after ensuring that the energy storage system is completely physically de-energized and shut down safely should the upgrade operation be performed, thereby fundamentally eliminating the possibility of hardware burnout or loss of control accidents caused by live upgrades.

[0040] A dual-layer protection mechanism is formed by a control chain that smoothly reduces power and an emergency shutdown operation that is executed based on the absolute value of the real-time total charging and discharging current of the energy storage battery pack. The first layer mechanism smoothly shuts down each energy branch according to the preset energy branch control sequence and the preset slope of each branch, minimizing the impact of various fluctuations and interferences during the power reduction process, so that the energy storage system can smoothly transition to a static state. The second layer mechanism is based on the absolute value of the real-time total charging and discharging current of the energy storage battery pack. It is used to indirectly reflect whether the energy storage system has experienced severe operating conditions such as device breakdown or external short circuit, which may cause the first layer mechanism to fail or react lagily. In this case, it bypasses the power reduction control sequence, directly disconnects the main controller and physically isolates the external energy input flow of each energy branch, shuts down the power conversion system, and achieves rapid risk avoidance in the event of a sudden severe operating condition.

[0041] The synergy of the two-layer mechanism enables the energy storage system to complement the "gradual and flexible power reduction" and the "rigid bypass shutdown operation", completely avoiding potential safety hazards during the transition of the energy storage system from an active state to a static state.

[0042] Preferably, the upgrade command further includes a delayed upgrade command, and in response to the delayed upgrade command, the energy storage system is upgraded, including: Download the upgrade package required for the energy storage system upgrade; Real-time monitoring of the total charging and discharging current of the energy storage system's battery pack; If the absolute value of the total real-time charging and discharging current is less than or equal to the preset current safety value for a duration that is greater than or equal to the preset continuous time, the energy storage system is determined to be in a static state, and the upgrade package has been downloaded, then the energy storage system is upgraded.

[0043] When the energy storage system is in an active state and responds to a user-requested delayed upgrade command, the system continues to operate, utilizing idle resources to download the necessary upgrade package. From the moment the delayed upgrade command is received, the system monitors the real-time total charging and discharging current of the battery pack. If the absolute value of the real-time total charging and discharging current is less than or equal to a preset current safety value for a duration greater than or equal to a preset continuous time (e.g., a 30-second filter window), the system is considered to be in a quasi-static electrical state, indicating a natural transition from an active to a static state. If the upgrade package download is completed within this duration, the absolute value of the real-time total charging and discharging current must still be less than or equal to the preset current safety value at the moment the upgrade operation is executed to prevent transient current surges. By asynchronously determining whether the absolute value of the real-time total charging and discharging current meets the standard with the download of the upgrade package using idle resources, the lag time window between the completion of the upgrade package download and the determination of electrical environmental compliance, common in traditional serial upgrades, is effectively eliminated. This avoids the risk of upgrade failure due to changes in operating conditions during the lag time window.

[0044] Furthermore, after responding to the delayed upgrade command, the energy storage system monitors the real-time total charging and discharging current. To avoid endless monitoring, a global monitoring time is preset. If the absolute value of the real-time total charging and discharging current is less than or equal to the preset current safety value for a period less than the preset continuous time within the preset global monitoring time, it indicates that although the energy storage system has not experienced severe operating conditions, the current electrical environment is already in an uncontrollable or unstable state. Alternatively, if the upgrade package is not downloaded within the preset global monitoring time, the highest level of safety defense operation is executed. This involves disconnecting the main controller through over-level protection, forcibly shutting down the external energy input flow of each energy branch, and shutting down the power conversion system. An emergency shutdown operation is then performed on the energy storage system. Only after ensuring that the energy storage system is completely in a physically de-energized and shut-down safe state is the upgrade operation executed, thereby fundamentally eliminating the possibility of hardware burnout or loss of control accidents caused by live upgrades.

[0045] Preferably, when the energy storage system is in a static state, in response to an upgrade command, if the absolute value of the total real-time charging and discharging current is less than or equal to a preset current safety value, the energy storage system is upgraded.

[0046] When the energy storage system is in a static state, comparing the absolute value of the total charging and discharging current in real time with the preset safe current value ensures that the energy storage system is in a quasi-static electrical state before performing upgrade operations, significantly improving operational efficiency and user experience. Specifically, regardless of whether the energy storage system is in a static or active state, before upgrading, the absolute value of the total charging and discharging current in real time must be compared with the preset safe current value to determine that the electrical conditions required for the energy storage system upgrade are good.

[0047] Preferably, it further includes: After the energy storage system is upgraded, the target operating status of the energy storage system is determined based on the operating status data obtained before the upgrade. According to the preset energy branch restoration sequence, the output power of each energy branch in the energy storage system is controlled to restore to the target operating state.

[0048] To quickly restore the energy storage system to its pre-upgrade operating state after an upgrade, the system's pre-upgrade operating status (active or idle) is determined based on pre-upgrade operating data, including the target power output. This target power output, along with the corresponding energy source and operating mode, is then defined as the target operating state for the energy storage system. It should be noted that the criteria for determining the target power range for active and idle states can be flexibly and adaptively set based on the actual operating conditions of the energy storage system, dispatch command protocols, or the technical parameters of core components.

[0049] After determining the target operating state, since different energy branches play different roles, this embodiment controls the output power of each energy branch to be restored to the output power before the upgrade according to the preset energy branch restoration sequence, based on the energy source of the target operating state and the preset power restoration change rate corresponding to each energy branch, thereby restoring the energy storage system to the target operating state and restoring the operating strategy before the upgrade (such as peak shaving and valley filling).

[0050] By combining the preset energy branch recovery sequence and the preset power recovery rate of each energy branch, the preset energy branch recovery control sequence determines the safe direction of energy flow, while the preset power recovery rate determines the physical speed of energy reconstruction. If there is only a recovery sequence without a gradual recovery, although the energy flow is correct, the transient step at startup can still generate extremely high-amplitude inrush currents, grid harmonic oscillations, and other electrical risks, as well as shorten the electrochemical lifespan of the solar panels. If there is only a gradual recovery without a reasonable recovery sequence, although the power increase rate is slow, an unreasonable recovery sequence can lead to risks such as instantaneous DC bus voltage collapse and power backflow. This embodiment combines both to ensure that throughout the entire power increase transition process, each energy branch and each power increase point in time is in a dual controllable state of "correct energy flow and moderate power increase rate," achieving a lossless, imperceptible, and safe transition from a static state to an active state. This lays a solid safety foundation for the system's safe and seamless transition to normal grid-connected operation.

[0051] Preferably, if the target operating state is an active state, the output power of each energy branch in the energy storage system is controlled to restore to the target operating state according to a preset energy branch restoration sequence, including: The output power of the photovoltaic branch and the output power of the power conversion system before the energy storage system upgrade are obtained based on the operating status data. During the preset zero-power maintenance time, the output power of each energy branch is controlled to remain at zero; The photovoltaic controller controls the output power of the photovoltaic branch to be restored to the power when responding to the upgrade command according to the third preset slope. After the output power of the photovoltaic branch is restored to the power at the time of responding to the upgrade command, the charging and discharging power between the energy storage system and the grid or load is controlled by the power conversion system to be restored to the power at the time of responding to the upgrade command according to the fourth preset slope.

[0052] After determining the target operating state as active based on the target power, the energy branch and its corresponding power data are determined according to the energy source before the upgrade. When the energy branch includes a photovoltaic branch and a power conversion system, the output power of the photovoltaic branch and the output power of the power conversion system at the time of responding to the upgrade command are obtained according to the operating state data before the upgrade. In this case, the corresponding preset energy branch recovery sequence is to first control the photovoltaic branch to restore its output power, and then control the power conversion system to restore its output power.

[0053] Specifically, the photovoltaic branch is first controlled to restore its output power. This means that the photovoltaic controller corresponding to the photovoltaic branch controls the output power of the photovoltaic branch to gradually restore it to the power at the time of responding to the upgrade command according to the third preset slope. Then, the power conversion system is controlled to restore its output power. Specifically, the power conversion system controls the charging and discharging power between the energy storage system and the external power grid or load to gradually restore it to the power at the time of responding to the upgrade command according to the fourth preset slope.

[0054] After the energy storage system starts up, during the preset zero-power maintenance time, the output power of the photovoltaic branch and the output power of the power conversion system are kept at zero to ensure the initial stability of each module of the energy storage system. During the preset power recovery time, the photovoltaic controller corresponding to the photovoltaic branch controls the output power of the photovoltaic branch to gradually recover to the power at the time of responding to the upgrade command according to the third preset slope. Then, the power conversion system is controlled to gradually recover the charging and discharging power between the energy storage system and the external grid or load to the power at the time of responding to the upgrade command according to the fourth preset slope.

[0055] This is because the photovoltaic branch continuously inputs electrical energy into the DC bus of the energy storage system when it is working, thus acting as an energy source. The power conversion system is the core channel for discharging and balancing the energy from the DC bus to the AC grid or load. By prioritizing the control of the photovoltaic branch's output power to gradually increase to the power required to respond to the upgrade command, the pre-safe injection and establishment of functional energy on the DC bus side is achieved from the source. During this process, the power conversion system remains locked or operates at extremely low output power, continuing to play a role in voltage clamping and balancing support. This effectively avoids the phenomenon of the DC bus energy being instantly drained and the voltage collapsing rapidly due to the priority activation of the power conversion system before the photovoltaic branch has established effective power output. It completely avoids serious electrical faults such as frequent protection trips, fuse breakdowns, or emergency lock-up of the battery management system caused by the instantaneous drop of the DC bus voltage below the undervoltage protection threshold, fundamentally ensuring the physical and electrical safety of the DC side during startup.

[0056] Specifically, during the dynamic transition period when photovoltaic output power increases and gradually recovers, the energy storage system is susceptible to severe fluctuations in solar irradiance or polarization effects. During this process, the power conversion system, which has not yet reached full load output, can retain sufficient reactive and active control bandwidth to dynamically offset the transient fluctuations in photovoltaic output power when injected into the DC bus. This ensures that the DC bus voltage and the output frequency of the energy storage system remain in stable closed-loop control throughout the entire transition process of large disturbances in power increase, effectively preventing the control system from oscillating or becoming unbalanced before heavy load.

[0057] Once the output power of the photovoltaic branch has fully recovered and stabilized, it indicates that the energy source on the DC side of the energy storage system has formed a robust energy foundation. At this point, the output power of the power conversion system is gradually increased to the power required to respond to the upgrade command. Under this control sequence, the power conversion system essentially performs grid connection and power ramp-up operations under healthy and excellent electrical conditions with highly stable DC voltage and abundant energy in the bus electrolytic capacitors. This greatly limits the turn-on electrical stress and overheating caused by excessive voltage / current changes in power semiconductor devices and other electronic components during the turn-on process, thereby significantly extending the physical lifespan of the core semiconductor switching components in the power conversion system.

[0058] It should be noted that the third and fourth preset slopes can be either fixed constants that remain constant during a single power increase, or variable slopes that are adaptively adjusted in real time according to the operating status of the energy storage system during the power increase. Specifically, the third and fourth preset slopes can be set once before the power increase is initiated, based on the historical operating conditions of the energy storage system. Alternatively, during the power increase process, real-time feedback parameters such as the DC bus voltage recovery rate, grid-side impedance characteristics, equipment junction temperature change rate, or real-time illumination change rate can be acquired and used to perform real-time closed-loop correction and adaptive adjustment of the third and fourth preset slopes. This results in a piecewise linear or non-linear change in the slope rise curve, ensuring optimal dynamic adaptation between the power recovery process and the current physical conditions of the power grid and equipment.

[0059] Preferably, if the energy storage system is also connected to distributed energy branches other than the photovoltaic branch, and the output power of the distributed energy branches when the energy storage system responds to the upgrade command is obtained based on the operating status data, then after the output power of the photovoltaic branch recovers to the power at the time of responding to the upgrade command, and before the power conversion system starts to restore the charging and discharging power, the following steps are also included: The controller corresponding to the distributed energy branch controls the output power of the distributed energy branch to be restored to the power at the time of responding to the upgrade command according to the corresponding preset power recovery slope.

[0060] When the energy branch includes not only the photovoltaic branch and the power conversion system, but also the distributed energy branch, the output power of the distributed energy branch when responding to the upgrade command is obtained based on the pre-upgrade operating status data. In this case, the corresponding preset energy branch recovery sequence is to first control the photovoltaic branch to restore its output power, then control the distributed energy branch to restore its output power, and finally control the power conversion system to restore its output power.

[0061] Specifically, controlling the distributed energy branch to restore the output power of the distributed energy branch means controlling the output power of the distributed energy branch to be restored to the power at the time of responding to the upgrade command by controlling the controller corresponding to the distributed energy branch according to the corresponding preset power restoration slope and gradually.

[0062] Furthermore, when the energy storage system is connected to multiple distributed energy branches before the upgrade (e.g., simultaneously connected to photovoltaic branches, wind power branches, fuel cell branches, or diesel power branches, and all distributed energy branches jointly supply power to the DC bus), the power recovery sequence among the distributed energy branches and the corresponding power recovery slope of each distributed energy branch can be flexibly set according to the actual operating conditions and the physical characteristics of the equipment itself. For example, after the energy storage system responds to the power recovery command, it can prioritize the power recovery of the distributed energy branch with the strongest DC voltage support and the most stable output, or prioritize the power recovery of the distributed energy branch with greater start-up inertia and a longer time to reach steady state, thereby achieving a smooth and gentle grid-connected start-up of multi-source heterogeneous systems.

[0063] More importantly, in the overall recovery chain that includes one or more distributed energy branches, the photovoltaic (PV) branch must be the highest priority response branch in the entire power recovery process. This is because the PV branch, as the most direct energy source, can provide the most basic potential support and energy foundation for the DC bus through its pre-established power. Correspondingly, the power conversion system must be the last link in the entire power recovery process to perform grid-connected restoration operations. This is because the power conversion system plays a role in actively releasing energy, dynamically balancing, and suppressing DC bus energy fluctuations in the energy storage system. Before the output power of the photovoltaic branch and all other distributed energy branches have fully and safely recovered to the power at the time of responding to the upgrade command, the energy supply on the DC side has not yet reached a steady-state balance. Under these circumstances, it is necessary to ensure that the power conversion system is in the final recovery state to ensure that the DC bus has a sufficient and stable energy source before it performs high-power charging and discharging tasks. This can effectively avoid the instantaneous energy shortage and voltage collapse of the DC bus caused by the power conversion system prioritizing high-power operation before the distributed energy branches have fully established power output. It also completely avoids serious electrical faults such as inverter loss of synchronism, protection tripping, or reverse current impact on distributed energy equipment caused by severe fluctuations in bus voltage, fundamentally ensuring the physical reliability and system-level electrical safety of the energy storage system after upgrade and restart.

[0064] Once the output power of each energy branch recovers to the power level at the time of responding to the upgrade command and stabilizes within the preset power recovery time, the energy storage system reaches the target operating state and continues the operating strategy before the upgrade.

[0065] Preferably, it further includes: If the target operating state is standby, the upgraded energy storage system will remain in standby state.

[0066] In this embodiment, when the target power is zero, the target operating state is a static state, which is further classified as a standby state. This means that the energy storage system was in a standby state before the upgrade, and will remain in a standby state after the upgrade.

[0067] This embodiment achieves the following technical effects through the above method: 1) According to the preset energy branch control sequence, the output power of each energy branch is controlled to decrease slowly, realizing a smooth transition from an active state to a static state for the multi-source heterogeneous energy storage system. This avoids the large jump in electrical energy caused by direct shutdown in existing technologies. During the process of reducing output power, the power conversion system plays a core role, fundamentally eliminating the physical hazards of arcing and voltage / current spikes breaking down semiconductor devices.

[0068] 2) By using a preset current safety value as a hard safety indicator and asynchronously downloading the upgrade package and monitoring it over a continuous time window in the background, the risk of control loop interruption, crashes, or system loss of control caused by control logic errors is avoided. On the other hand, the upgrade operation is performed during the natural idle time of the energy storage system, minimizing the interference of the upgrade process on the user's charging and discharging tasks and economic benefits.

[0069] 3) After the energy storage system is upgraded and restarted, it is initialized after a preset zero-power maintenance time, and then the output power of each energy branch is restored smoothly according to the preset energy branch restoration sequence. This eliminates the cumbersome manual reconfiguration required after the energy storage upgrade in the existing technology, and ensures the seamless and continuous operation of the energy storage system after the upgrade.

[0070] Example 2 Based on the principles described in Embodiment 1, an energy storage system upgrade device 100 is also proposed, such as... Figure 2 As shown, it includes: The first unit 110 is used to obtain the operating status data of the energy storage system in response to the upgrade command when the energy storage system is in operation. The operating status indicates that the energy storage system is in normal operation and there is power flow. The operating status data includes the output power of the photovoltaic branch and the output power of the power conversion system. The second unit 120 is used to control the output power of the photovoltaic branch to decrease to zero at a first preset slope according to the operating status data through the photovoltaic controller. The third unit 130 is used to control the charging and discharging power between the energy storage system and the grid or load to decrease to zero according to the second preset slope after the output power of the photovoltaic branch is reduced to zero through the power conversion system. Unit 4, 140, is used to upgrade the energy storage system when it is determined that the energy storage system is in a quiescent state; the quiescent state indicates that the energy storage system is powered on but there is no power conversion between the energy storage system and the external power grid or load.

[0071] Preferably, it further includes: Unit 5, 150, is used to determine the target operating status of the energy storage system based on the operating status data obtained before the upgrade, after the energy storage system has been upgraded. Unit 160 is used to control the output power of each energy branch in the energy storage system to be restored to the target operating state according to the preset energy branch restoration sequence.

[0072] Example 3

[0073] Furthermore, an electronic device is proposed, comprising: processor; Memory used to store processor-executable instructions; The processor is configured to implement an energy storage system upgrade method of Embodiment 1 when executing executable instructions.

[0074] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0075] Furthermore, it should be noted that the use of terms such as "first," "second," and "a" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly specified. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0076] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0077] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A method for upgrading an energy storage system, characterized in that, include: When the energy storage system is in operation, in response to the upgrade command, the operating status data of the energy storage system is acquired; The operating status indicates that the energy storage system is in normal operation and there is power flow. The operating status data includes the output power of the photovoltaic branch and the output power of the power conversion system. Based on the operating status data, the photovoltaic controller controls the output power of the photovoltaic branch to decrease to zero at a first preset slope. After the output power of the photovoltaic branch is reduced to zero, the charging and discharging power between the energy storage system and the grid or load is controlled by the power conversion system to be reduced to zero according to the second preset slope. If the energy storage system is determined to be in a quiescent state, the energy storage system is upgraded; the quiescent state indicates that the energy storage system is powered on but there is no power conversion between the energy storage system and the external power grid or load.

2. The method according to claim 1, characterized in that, If the energy storage system also includes distributed energy branches other than the photovoltaic branch, then after the output power of the photovoltaic branch drops to zero and before the power conversion system starts to reduce the charging and discharging power, it also includes: The controller corresponding to the distributed energy branch controls the output power of the distributed energy branch to decrease to zero according to the corresponding preset power reduction slope.

3. The method according to claim 1, characterized in that, If the energy storage system is determined to be in a quiescent state, upgrading the energy storage system includes: If, within a preset power adjustment time, the absolute value of the total real-time charging and discharging current of the energy storage system battery pack is less than or equal to a preset current safety value, the energy storage system is upgraded. If the absolute value of the total real-time charging and discharging current is greater than the preset current safety value, the energy storage system is controlled to enter the shutdown state, and the energy storage system is upgraded after completion.

4. The method according to claim 1, characterized in that, The upgrade command also includes a delayed upgrade command, in response to which the energy storage system is upgraded, including: Download the upgrade package required for the energy storage system upgrade; Real-time monitoring of the total charging and discharging current of the energy storage system's battery pack; If the absolute value of the real-time total charging and discharging current is less than or equal to the preset current safety value for a duration that is greater than or equal to the preset continuous time, the energy storage system is determined to be in a static state, and the upgrade package is downloaded, then the energy storage system is upgraded.

5. The method according to claim 1, characterized in that, Also includes: After the energy storage system is upgraded, the target operating state of the energy storage system is determined based on the operating status data obtained before the upgrade. According to the preset energy branch restoration sequence, the output power of each energy branch in the energy storage system is controlled to be restored to the target operating state.

6. The method according to claim 5, characterized in that, If the target operating state is active, the output power of each energy branch in the energy storage system is restored to the target operating state according to the preset energy branch restoration sequence, including: The output power of the photovoltaic branch and the output power of the power conversion system before the upgrade of the energy storage system are obtained based on the operating status data. During the preset zero-power maintenance time, the output power of each energy branch is controlled to remain at zero; The photovoltaic controller controls the output power of the photovoltaic branch to be restored to the power when responding to the upgrade command according to the third preset slope. After the output power of the photovoltaic branch is restored to the power at the time of responding to the upgrade command, the power conversion system controls the charging and discharging power between the energy storage system and the grid or load to be restored to the power at the time of responding to the upgrade command according to the fourth preset slope.

7. The method according to claim 6, characterized in that, If the energy storage system is also connected to distributed energy branches other than the photovoltaic branch, and the output power of the distributed energy branch when the energy storage system responds to the upgrade command is obtained based on the operating status data, then after the output power of the photovoltaic branch recovers to the power at the time of responding to the upgrade command, and before the power conversion system starts to restore the charging and discharging power, the following steps are also included: The controller corresponding to the distributed energy branch controls the output power of the distributed energy branch to recover to the power at the time of responding to the upgrade command according to the corresponding preset power recovery slope.

8. The method according to claim 5, characterized in that, Also includes: If the target operating state is standby, the upgraded energy storage system remains in standby state.

9. An energy storage system upgrade device, characterized in that, include: The first unit is used to obtain the operating status data of the energy storage system in response to an upgrade command when the energy storage system is in operation. The operating status indicates that the energy storage system is in normal operation and there is power flow. The operating status data includes the output power of the photovoltaic branch and the output power of the power conversion system. The second unit is used to control the output power of the photovoltaic branch to decrease to zero at a first preset slope according to the operating status data via the photovoltaic controller. The third unit is used to control the charging and discharging power between the energy storage system and the grid or load to decrease to zero at a second preset slope after the output power of the photovoltaic branch is reduced to zero through the power conversion system. The fourth unit is used to upgrade the energy storage system when it is determined that the energy storage system is in a quiescent state; the quiescent state indicates that the energy storage system is powered on but there is no power conversion between the energy storage system and the external power grid or load.

10. The energy storage system upgrade device as described in claim 9, characterized in that, Also includes: The fifth unit is used to determine the target operating state of the energy storage system based on the operating state data obtained before the upgrade, after the energy storage system has been upgraded. The sixth unit is used to control the output power of each energy branch in the energy storage system to be restored to the target operating state according to the preset energy branch restoration sequence.

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