A dynamic high voltage control method and system based on multi-battery cluster of energy storage system

Abstract

The application relates to the technical field of energy storage system control, and discloses a dynamic high-voltage control method and system based on a multi-battery cluster of an energy storage system, wherein the method comprises the following steps: collecting total voltages of each battery cluster and sorting the total voltages from high to low; calculating adjacent voltage differences; if any difference is greater than or equal to a set threshold value, terminating high-voltage access; if all the differences are less than the set threshold value, performing high-voltage access on the battery clusters in the order from low to high total voltage; when any newly accessed cluster fails, excluding the cluster and recalculating the adjacent voltage differences of the remaining battery clusters and judging whether to access high voltage, until all accessible clusters succeed or there is no accessible cluster; counting the number of failed clusters and the number of running fault clusters of high-voltage access failure, and if the total number is greater than a preset redundancy number, cutting off the high voltage as a whole, otherwise, only cutting off the corresponding fault cluster. The application greatly improves the availability of the energy storage system and avoids long-term shutdown of the whole system caused by single-cluster failure.

Description

Technical Field

[0001] This invention relates to the field of energy storage system control technology, and in particular to a dynamic high-voltage control method and system based on multiple battery clusters in an energy storage system. Background Technology

[0002] As energy storage systems continue to evolve towards larger capacity and higher power, to meet the demands for longer backup time and greater operating power, current energy storage systems generally adopt a topology where multiple battery clusters operate in parallel via a DC bus. Under this architecture, each battery cluster needs to be connected to the high-voltage DC bus sequentially during system startup (connecting to the high-voltage bus), and during operation, high-voltage disconnection (removing from the high-voltage bus) or reconnection is required depending on fault conditions or maintenance needs. Therefore, the high-voltage connection and disconnection management strategy for battery clusters directly affects the operational safety and power supply continuity of the energy storage system.

[0003] In existing technologies, high-voltage management of multi-cell parallel energy storage systems generally adopts a simultaneous up-and-down control mode. This means that when any cell cluster fails or malfunctions, all cell clusters in the entire energy storage system are powered down, causing a complete system shutdown until the faulty cluster is repaired or replaced. While this management method is logically simple and easy to implement, it has significant limitations: a single cluster failure leads to a complete system outage, and after-sales maintenance personnel often cannot arrive on-site quickly enough to handle the fault and restore the system. This results in the energy storage system being unable to provide power to customers for extended periods, causing economic losses and a decline in user experience.

[0004] In response to the above problems, some existing technical solutions have proposed improvement measures, but they still have their own defects and shortcomings.

[0005] Patent application CN117375054A discloses a high-voltage access control method for an energy storage system. The method uses a main control unit to select battery clusters that meet the voltage and state of charge (SOC) conditions to form an initial set. The set with the largest number of clusters is selected as the target set, and then connected to the DC bus after unified voltage regulation via a DC-DC converter. Regarding fault handling, upon receiving fault information, this scheme sends a current-limiting command to the DC-DC converter corresponding to the faulty cluster, limiting the current of the faulty cluster and then disconnecting it. However, this scheme does not distinguish between normal and faulty clusters during the initial high-voltage connection phase. Faulty clusters may still be included in the target set before the fault is completely eliminated, posing a safety hazard. Furthermore, this scheme lacks a quantitative judgment mechanism between the number of faulty clusters and the overall system availability. When the number of faulty clusters reaches a certain level, the remaining clusters may not be able to safely carry the system's power demand, but this scheme lacks proactive judgment and high-voltage protection mechanisms. In addition, this scheme mainly addresses fault handling during the high-voltage connection process and lacks batch processing and system-level judgment logic for situations where multiple clusters suddenly fail during normal system operation.

[0006] Patent application CN118074262A discloses a centralized parallel battery cluster high-voltage dynamic switching algorithm. It monitors battery clusters not connected to the bus in real time, detecting the difference between their total cluster voltage and the bus high voltage. If the difference is less than a set value, the clusters are directly connected; otherwise, the PCS (Power Control System) charges and discharges the already connected clusters to adjust the bus voltage, allowing them to connect again once the conditions are met. This scheme processes only one switching target at a time, making batch processing and overall optimization impossible when multiple clusters need to be connected simultaneously, resulting in low switching efficiency. Furthermore, this scheme relies on the PCS for bus voltage regulation, which involves long communication links and control cycles, leading to slow response times and impacting the normal operation of the entire energy storage system. The scheme also primarily targets battery clusters reconnected after normal maintenance, neglecting to count the number of faulty clusters during operation and lacking a mechanism to determine the system's continued operational capability based on the number of faulty clusters.

[0007] Patent application CN122203507A discloses a protection system for a battery cluster balancing circuit. This system detects system parameters through a detection circuit, triggers a protection signal based on these parameters, and a coordination controller performs tiered control based on the fault type corresponding to the protection signal, including differentiated handling for hardware faults, software faults, and cell faults. However, this solution focuses on protecting the balancing circuit itself, primarily addressing overvoltage issues on the output side. It fails to organically integrate fault handling with the overall high-voltage power-on and power-off process of the energy storage system, lacking unified management of normal and faulty clusters during high-voltage power-on and power-off processes. This solution only provides control after a fault occurs, without pre-judging and screening battery clusters before high-voltage power-on, thus failing to prevent problems caused by faulty clusters connecting to the bus. Furthermore, while this solution requires disconnecting the high-voltage circuit breaker of the faulty cluster in both hardware and cell fault cases, it does not provide a quantitative standard for determining whether the remaining system can still operate safely after the faulty cluster is removed.

[0008] In summary, existing technologies for high-voltage management of multi-cell cluster energy storage systems have the following common shortcomings: lack of proactive prediction and screening mechanism for cell cluster fault status before high voltage is applied; lack of unified accumulation and linkage decision-making mechanism for high-voltage failed clusters and operational faulty clusters; lack of quantitative judgment model between the number of faulty clusters and system availability; and inability to achieve differentiated treatment of system continued operation and only the faulty clusters being cut off when some clusters fail. Summary of the Invention

[0009] To address the aforementioned issues, this invention proposes a dynamic high-voltage control method and system based on multiple battery clusters in an energy storage system, which significantly improves the availability of the energy storage system and avoids prolonged system downtime due to single cluster failures.

[0010] The technical solution adopted in this invention is as follows: A dynamic high-voltage control method based on multiple battery clusters in an energy storage system includes: Collect the total voltage of each battery cluster and sort them from highest to lowest; Calculate the voltage difference between adjacent voltages. If any difference is greater than or equal to a set threshold, terminate the high-voltage access. If all differences are less than the set threshold, perform high-voltage access cluster by cluster in order of total voltage from low to high. If any new access cluster fails, it is excluded, and the adjacent voltage difference of the remaining battery clusters is recalculated and it is determined whether high voltage access is possible, until all accessible clusters are successful or no clusters can be accessed. The system counts the number of failed high-voltage clusters and the number of operational fault clusters. If the total number exceeds the preset redundancy limit, the entire high-voltage system is disconnected; otherwise, only the corresponding fault cluster is disconnected.

[0011] Furthermore, the step of collecting the total voltage of each battery cluster and sorting it from high to low includes: The total voltage value of each battery cluster reported by the slave BMS is obtained by the main control BMS. All the obtained total voltage values ​​are arranged in descending order of value to form a voltage sorting sequence.

[0012] Further, the calculation of adjacent voltage differences, and termination of high-voltage access if any difference is greater than or equal to a set threshold, includes: The total voltage of the battery clusters in adjacent positions after sorting is calculated by difference to obtain the voltage difference between each adjacent group, and each adjacent voltage difference is compared with a set threshold. If any adjacent voltage difference is greater than or equal to the set threshold, it is determined that the voltage difference between the current battery clusters is too large, and the high-voltage access process of all battery clusters is terminated, and no high-voltage access command is sent to any battery cluster.

[0013] Furthermore, the step of performing high-voltage access cluster by cluster in ascending order of total voltage if all differences are less than a set threshold includes: When all adjacent voltage differences are less than a set threshold, the battery cluster with the lowest total voltage is determined from the voltage sorting sequence as the first cluster to be connected. High-voltage access operations are performed on each cluster in ascending order of total voltage. Only one cluster is accessed at any given time. Once the current cluster has completed high-voltage access and the access is confirmed to be successful, the high-voltage access operation is then performed on the next cluster in sequence.

[0014] Furthermore, if any new access cluster fails, it is excluded, and the adjacent voltage difference of the remaining battery clusters is recalculated, and it is determined whether high-voltage access is possible, until all accessible clusters are successfully accessed or no clusters can be accessed, including: During the high-voltage access process, if the battery cluster currently performing the high-voltage access operation fails to precharge or has an access failure, the battery cluster will be marked as an access failure cluster and removed from the voltage sorting sequence, and will not participate in subsequent high-voltage access operations. For the remaining battery clusters to be connected after removing the failed cluster, their total voltages are re-acquired and reordered from high to low; the adjacent voltage differences after reordering are recalculated and compared with a set threshold; if there is a value greater than or equal to the set threshold in the recalculated adjacent voltage differences, the high-voltage connection of all subsequent battery clusters is terminated; if all recalculated adjacent voltage differences are less than the set threshold, the high-voltage connection operation is continued to be performed cluster by cluster starting from the lowest voltage cluster in order of total voltage from low to high after reordering. Repeat the above process of elimination, reordering, recalculating pressure difference, and rejuvenating until all battery clusters that have not experienced connection failures are successfully connected to the high voltage, or the connection of the remaining clusters to be connected is terminated because the pressure difference does not meet the conditions.

[0015] Furthermore, the statistical count of failed clusters and operational fault clusters for high-voltage access failure includes: Throughout the entire process from the start of high-voltage access to its completion, the total number of clusters marked as access failures is accumulated to obtain the number of high-voltage access failure clusters. During the period when the high voltage connection is completed and the battery clusters are in normal operation, the operating status of each connected battery cluster is monitored in real time. When any battery cluster experiences an operational failure and the high voltage is disconnected, the cluster is counted as an operational failure cluster to obtain the total number of operational failure clusters.

[0016] Furthermore, the step of cutting off the entire high voltage if the total number is greater than the preset redundancy number, and cutting off only the corresponding fault cluster if the total number is greater than the preset redundancy number, includes: Calculate the sum of the number of high-voltage access failure clusters and the number of operational fault clusters to obtain the total number of fault clusters; compare the total number of fault clusters with the preset redundancy number; If the total number of faulty clusters is less than or equal to the preset redundancy number, it is determined that the energy storage system still has sufficient redundancy to maintain normal operation. Only the high-voltage access failure clusters and the operating fault clusters are disconnected from the high-voltage bus, while the remaining battery clusters that have been normally connected and have not experienced any faults continue to operate under the high-voltage access status. If the total number of faulty clusters exceeds the preset redundancy, it is determined that the power carrying capacity of the remaining normal clusters in the energy storage system is insufficient to meet the minimum requirements for safe operation of the system. In this case, an overall high-voltage cutoff operation is performed, disconnecting all battery clusters connected to the high-voltage bus from the bus.

[0017] Furthermore, the step of removing only the high-voltage access failure cluster and the operational fault cluster from the high-voltage bus includes: The main control BMS sends high-voltage disconnection commands to the slave control BMSs of the battery clusters marked as having failed high-voltage access and those that have experienced operational failures. After receiving the high voltage cut-off command, each slave control BMS controls the high voltage contactor of the corresponding battery cluster to disconnect, so that the battery cluster is disconnected from the high voltage bus. The remaining battery clusters that have not received a high-voltage cutoff command keep their high-voltage contactors closed and continue to supply power to or draw power from the high-voltage bus.

[0018] Furthermore, the overall high-pressure cutoff operation includes: The main control BMS broadcasts a high-voltage cut-off command to all slave control BMSs of battery clusters that have been connected to the high-voltage bus. After receiving the high-voltage cutoff command, each slave control BMS disconnects the high-voltage contactor of its respective battery cluster in a predetermined order, so that all battery clusters are disconnected from the high-voltage bus one by one until all battery clusters are in the high-voltage cutoff state.

[0019] A dynamic high-voltage control system based on multiple battery clusters in an energy storage system includes a central control BMS and slave control BMSs respectively located in each battery cluster; The master control BMS is configured to: collect the total voltage of each battery cluster and sort them from high to low; calculate the voltage difference between adjacent clusters, and if any difference is greater than or equal to a set threshold, terminate high-voltage access; if all differences are less than the set threshold, control the corresponding slave control BMS to perform high-voltage access cluster by cluster in order of total voltage from low to high; when any new access cluster fails, exclude the cluster, recalculate the voltage difference between adjacent clusters of the remaining battery clusters and determine whether to continue high-voltage access, until all accessible clusters are successful or there are no accessible clusters; count the number of failed high-voltage access clusters and the number of faulty operating clusters, and control the overall high-voltage cut-off when the total number is greater than the preset redundancy number, otherwise only control the cut-off of the corresponding faulty clusters.

[0020] The beneficial effects of this invention are as follows: 1. This invention employs an access judgment mechanism that collects and sorts the total voltage of each battery cluster, calculates the voltage difference between adjacent clusters, and compares it with a set threshold. High-voltage access is only permitted when all voltage differences meet safety conditions, effectively preventing high-current circulating shocks caused by excessive inter-cluster voltage differences. By accessing clusters sequentially from low to high total voltage, the voltage difference between each cluster and the bus is minimized, suppressing circulating currents at the source. When any cluster fails to access, it is dynamically excluded, and the remaining cluster voltage differences are recalculated before continued access, ensuring the high-voltage access process is not completely halted by individual cluster failures. By statistically analyzing the number of failed access clusters and the number of operating faulty clusters and comparing them with a preset redundancy number, only faulty clusters are removed while normal clusters continue operating when the total number of faults does not exceed the system's redundancy capacity. When the total number of faults exceeds the redundancy capacity, overall high-voltage access is implemented, ensuring both system safety and maximizing system availability. These technical features work together synergistically to form a complete closed-loop management scheme for high-voltage access, dynamic fault elimination, unified fault statistics, and quantitative decision-making regarding system availability.

[0021] 2. This invention employs a cluster-by-cluster connection sequence prioritizing the lowest total voltage. Compared to existing technologies with disordered or undefined connection sequences, this minimizes the voltage difference between each connected battery cluster and the established bus voltage, significantly reducing the inrush current during connection. This effectively protects the high-voltage contactor and bus power devices, extending equipment lifespan. Furthermore, by dynamically eliminating failed clusters and recalculating the voltage difference before continuing connection, it avoids the problem of repeated restarts or complete failures of the high-voltage connection process due to individual cluster failures. This greatly improves the success rate of high-voltage connection on the first attempt and reduces system startup waiting time.

[0022] 3. This invention establishes a quantitative judgment model for system availability based on the comparison between the total number of faulty clusters and a preset redundancy number. It incorporates failed clusters during the high-voltage access phase and faulty clusters during the operation phase into a unified statistical framework. This preset redundancy number reflects the intrinsic relationship between the total number of system clusters, the battery cluster overcurrent fault rate, and the rated operating rate. When the total number of faulty clusters does not exceed the preset redundancy number, the system determines that the remaining normal clusters still have sufficient power carrying capacity, and only the faulty clusters are disconnected while the remaining clusters continue to operate. When the total number of faulty clusters exceeds the preset redundancy number, the system determines that the power carrying capacity of the remaining clusters is insufficient to meet the minimum requirements for safe operation, and automatically performs overall high-voltage shutdown. This quantitative judgment mechanism provides a scientific basis for system decision-making between continued operation and overall shutdown, avoiding unnecessary system-wide shutdown when redundancy is sufficient, and also avoiding the overload risk caused by forced operation when redundancy is insufficient.

[0023] 4. Compared to existing technologies that only focus on single-cluster switching or handle only a single type of fault, this invention achieves unified management of the entire lifecycle of high-voltage connection failures and operational faults, covering the complete process of the energy storage system from high-voltage connection to normal operation and fault handling. Simultaneously, this invention does not rely on PCS for bus voltage regulation, avoiding the response delays caused by the long communication links and control cycles involved in PCS regulation. This results in faster fault handling and less impact on normal system operation. Furthermore, when the number of faulty clusters does not exceed the system's redundancy capacity, the system only disconnects the faulty clusters while the remaining clusters continue to operate normally. This truly achieves the goal of partial cluster failure without system downtime, significantly improving the availability of the energy storage system and avoiding economic losses to customers caused by prolonged system downtime due to a single cluster failure. Attached Figure Description

[0024] Figure 1 This is a flowchart of a dynamic high-voltage control method based on multiple battery clusters in an energy storage system, according to Embodiment 1 of the present invention. Detailed Implementation

[0025] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments are now described. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; that is, the described embodiments are only a part of the embodiments of the invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0026] Example 1 like Figure 1 As shown, this embodiment provides a dynamic high-voltage control method based on multiple battery clusters in an energy storage system, including: Collect the total voltage of each battery cluster and sort them from highest to lowest; Calculate the voltage difference between adjacent voltages. If any difference is greater than or equal to a set threshold, terminate the high-voltage access. If all differences are less than the set threshold, perform high-voltage access cluster by cluster in order of total voltage from low to high. If any new access cluster fails, it is excluded, and the adjacent voltage difference of the remaining battery clusters is recalculated and it is determined whether high voltage access is possible, until all accessible clusters are successful or no clusters can be accessed. The system counts the number of failed high-voltage clusters and the number of operational fault clusters. If the total number exceeds the preset redundancy limit, the entire high-voltage system is disconnected; otherwise, only the corresponding fault cluster is disconnected.

[0027] Preferably, the total voltage value of each battery cluster reported by the slave BMS is obtained by the master control BMS, and all the obtained total voltage values ​​are arranged in descending order of value to form a voltage sorting sequence.

[0028] Specifically, the master control BMS and each slave control BMS establish a data connection via a communication bus. In the initial stage of the high-voltage access process, the master control BMS broadcasts a voltage reporting request to all slave control BMSs via this communication bus. Upon receiving the request, each slave control BMS collects the total voltage value of its own battery cluster through its internal voltage sampling circuit and replies to the master control BMS in the form of data frames. The master control BMS extracts the total voltage value of each battery cluster from each data frame, then calls its internal data processing module to sort all the acquired total voltage values ​​in descending order, ultimately forming a voltage sorting sequence containing the total voltage values ​​of all battery clusters. This voltage sorting sequence is stored in the master control BMS's storage unit in the form of a list or array for subsequent differential voltage calculations and access order decisions.

[0029] It should be noted that centralized acquisition and sorting of voltage data are achieved through communication and interaction between the central control BMS and each slave control BMS, resulting in high data processing efficiency and good real-time performance. The sorted sequence makes the voltage relationship between each battery cluster immediately clear, facilitating the central control BMS to quickly determine the access order and calculate the adjacent voltage difference.

[0030] Preferably, the total voltage of the battery clusters in adjacent positions after sorting is calculated by difference to obtain the voltage difference between each adjacent cluster, and each adjacent voltage difference is compared with a set threshold. If any adjacent voltage difference is greater than or equal to the set threshold, it is determined that the voltage difference between the current battery clusters is too large, and the high voltage access process of all battery clusters is terminated as a whole, and no high voltage access command is sent to any battery cluster.

[0031] Specifically, after obtaining the voltage sorting sequence, the central control BMS calculates the difference between the total voltages of adjacent battery clusters, starting from the highest voltage cluster, in sequence. For example, subtracting the total voltage of the second-ranked battery cluster from the total voltage of the first-ranked cluster yields the first adjacent voltage difference; subtracting the total voltage of the third-ranked cluster from the total voltage of the second-ranked cluster yields the second adjacent voltage difference; and so on, until all adjacent voltage differences are calculated. After calculating all adjacent voltage differences, the central control BMS reads each voltage difference value from the storage unit and compares it with a preset threshold stored internally. During this comparison, if any adjacent voltage difference is found to be greater than or equal to the preset threshold, the central control BMS immediately stops all subsequent comparisons and access processes, determining that the voltage difference between the current battery clusters is too large, and terminating the high-voltage access process for all battery clusters. In the terminated state, the master control BMS does not send high-voltage access commands to any slave control BMS of any battery cluster. The system maintains the high-voltage disconnection state and outputs an alarm message for excessive voltage difference, waiting for manual intervention.

[0032] It should be noted that a rigorous screening mechanism, which compares each adjacent voltage difference with a threshold, ensures that the voltage deviation between any two adjacent battery clusters does not exceed the safe range, thereby guaranteeing that the voltage consistency among all battery clusters meets the access requirements. Access is immediately terminated upon detection of any anomaly, effectively avoiding the risk of equipment damage caused by excessive local voltage differences.

[0033] Preferably, when all adjacent voltage differences are less than a set threshold, the battery cluster with the lowest total voltage is determined from the voltage sorting sequence as the first cluster to be connected; high-voltage access operation is performed on each cluster in order of total voltage from low to high, and high-voltage access operation is performed on only one battery cluster at each time. After the current cluster completes high-voltage access and confirms success, high-voltage access operation is performed on the next cluster in sequence.

[0034] Specifically, after comparing all adjacent voltage differences one by one, the main control BMS determines that if all adjacent voltage differences are less than a set threshold, it enters the access execution phase. The main control BMS first finds the cluster identifier corresponding to the battery cluster with the lowest total voltage value in the voltage sorting sequence, identifying this cluster as the first cluster to be accessed. Then, the main control BMS sends high-voltage access commands one by one in ascending voltage order. During execution, the main control BMS sends a high-voltage access command to only one slave control BMS of a battery cluster at any given time. After that slave control BMS completes the pre-charging operation and closes the high-voltage contactor, it replies with a high-voltage access success status to the main control BMS. Upon receiving this success status, the main control BMS selects the next battery cluster with the second lowest voltage and sends a high-voltage access command to its slave control BMS. This process continues until all battery clusters to be accessed have been processed in ascending voltage order.

[0035] It should be noted that adopting the lowest voltage priority access sequence can minimize the inrush current when each cluster is accessed. At the same time, the serial access method of only one cluster at a time avoids the superimposed impact caused by multiple clusters accessing at the same time, so that the bus voltage is established gradually and the entire access process is stable and controllable.

[0036] Preferably, during the cluster-by-cluster high-voltage access process, if the battery cluster currently performing the high-voltage access operation experiences a pre-charging failure or access fault, the battery cluster is marked as an access failure cluster and removed from the voltage sorting sequence, and will not participate in subsequent high-voltage access operations. For the remaining battery clusters to be accessed after removing the failure cluster, their total voltages are re-acquired and re-sorted from high to low. The adjacent voltage differences after re-sorting are recalculated and compared with a set threshold. If there is a value greater than or equal to the set threshold in the recalculated adjacent voltage differences, the high-voltage access of all subsequent battery clusters is terminated. If all recalculated adjacent voltage differences are less than the set threshold, the high-voltage access operation continues to be performed cluster by cluster, starting from the lowest voltage cluster, according to the order of the re-sorted total voltage from low to high. The above process of exclusion, re-sorting, recalculating voltage differences, and re-judgment is repeated until all battery clusters that have not experienced access failures have successfully accessed the high voltage, or the remaining clusters to be accessed are terminated due to insufficient voltage differences.

[0037] Specifically, in the serial process of high-voltage access cluster by cluster, after the master control BMS sends a high-voltage access command to the slave control BMS of a certain battery cluster, the slave control BMS performs a pre-charge operation. The pre-charge operation includes closing the pre-charge contactor to perform current-limited charging of the bus capacitor through the pre-charge resistor. If, during the pre-charge process, the slave control BMS detects an abnormal pre-charge current, a pre-charge timeout, or a failure of the bus voltage to rise to a preset ratio within a specified time, the access of that cluster is determined to have failed. At this time, the slave control BMS reports the high-voltage access failure status to the master control BMS. After receiving the failure status, the master control BMS marks the battery cluster as an access failure cluster and removes it from the current voltage sorting sequence. After the removal operation is completed, the master control BMS re-executes the voltage acquisition and sorting process for the remaining battery clusters to be accessed, that is, it re-requests the total voltage from the slave control BMS of the remaining clusters and re-forms the sorting sequence in descending order.

[0038] After reordering, the master control BMS recalculates the voltage difference between adjacent positions in the new sequence and compares it with a set threshold one by one. If any of the recalculated voltage differences is greater than or equal to the set threshold, it indicates that the voltage consistency among the remaining clusters after excluding the failed clusters no longer meets safety requirements. The master control BMS then terminates the high-voltage connection for all subsequent battery clusters, and the process ends. If all recalculated voltage differences are less than the set threshold, the master control BMS, according to the reordered sequence, starts again from the battery cluster with the lowest total voltage and performs the high-voltage connection operation cluster by cluster.

[0039] The execution sequence of the entire process is as follows: exclude failed clusters, reorder, recalculate the differential pressure, re-judge, and continue to connect. This sequence is executed cyclically until all battery clusters that have not failed to connect are successfully connected to the high voltage, or the connection is terminated because the differential pressure does not meet the conditions after a certain re-judgment.

[0040] It should be noted that this dynamic exclusion and reassessment mechanism enables the high-voltage access process to be adaptive. When the access of a cluster fails, the system will not simply terminate the entire process or blindly continue accessing. Instead, it will reassess the voltage matching between the remaining clusters and only continue accessing if the safety conditions are met. This cyclical processing method maximizes the system's access success rate while avoiding safety hazards caused by excessive voltage differences between the remaining clusters after the faulty cluster has been eliminated.

[0041] Preferably, during the entire process from the start of high-voltage access to its completion, the number of all clusters marked as access failures is accumulated to obtain the high-voltage access failure cluster count; during the period when high-voltage access is completed and the system is in normal operation, the operating status of each accessed battery cluster is monitored in real time. When any battery cluster experiences an operational failure and its high voltage is disconnected, that cluster is counted as an operational failure cluster to obtain the operational failure cluster count.

[0042] Specifically, the central control BMS initializes an access failure counter when the system initiates the high-voltage access process, setting the initial value of the counter to zero. Subsequently, throughout the entire high-voltage access process, whenever the central control BMS marks a battery cluster as an access failure cluster due to a pre-charging failure or access fault, the central control BMS automatically increments the current value of the access failure counter. This counting process continues until the high-voltage access process is completely completed, i.e., all accessible clusters have successfully accessed or access has terminated due to insufficient voltage differential. The final value of the access failure counter is the number of high-voltage access failure clusters.

[0043] On the other hand, during the period when the system has completed high-voltage connection and is in normal operation, the central control BMS continuously monitors the operating parameters of each connected battery cluster, including but not limited to the current, voltage, and temperature of each cluster. When the central control BMS detects an operational fault such as overcurrent, overvoltage, undervoltage, or overtemperature in any battery cluster, it sends a high-voltage disconnection command to the slave control BMS of that cluster and simultaneously adds that cluster to the operational fault count, i.e., updates the operational fault counter. The operational fault counter remains valid during normal system operation and is incremented each time an operational fault occurs that leads to high-voltage disconnection.

[0044] It should be noted that separating access failures and operational malfunctions into separate statistics allows the system to differentiate between anomalies at different stages. This separate accumulation method provides accurate breakdown data for calculating the final total number of fault clusters, facilitating a comprehensive consideration of the impact of faults at different stages when assessing system availability.

[0045] Preferably, the total number of faulty clusters is calculated by summing the number of high-voltage access failure clusters and the number of operational faulty clusters; the total number of faulty clusters is compared with a preset redundancy number; if the total number of faulty clusters is less than or equal to the preset redundancy number, it is determined that the energy storage system still has sufficient redundancy to maintain normal operation, and only the high-voltage access failure clusters and operational faulty clusters are disconnected from the high-voltage bus, while the remaining normally connected and fault-free battery clusters continue to operate under high-voltage access status; if the total number of faulty clusters is greater than the preset redundancy number, it is determined that the power carrying capacity of the remaining normal clusters of the energy storage system is insufficient to meet the minimum requirements for safe operation of the system, and an overall high-voltage disconnection operation is performed, disconnecting all battery clusters connected to the high-voltage bus from the bus.

[0046] Specifically, whenever system availability needs to be assessed, the central control BMS reads the current values ​​of the access failure counter and the operational failure counter, and adds them together to obtain the total number of faulty clusters. Then, the central control BMS reads a preset redundancy number from the storage unit and compares the total number of faulty clusters with this preset redundancy number. The value of this preset redundancy number is related to the total number of clusters in the system and the rated operating parameters of each battery cluster. If the comparison result shows that the total number of faulty clusters is less than or equal to the preset redundancy number, the central control BMS determines that the system still has sufficient redundancy. At this time, the central control BMS executes a selective disconnection strategy, that is, it only sends high-voltage disconnection commands to the slave control BMSs of the battery clusters marked as having access failures and operational failures, disconnecting these faulty clusters from the high-voltage bus; while the remaining battery clusters that are normally connected and have not experienced failures do not receive high-voltage disconnection commands, keep the high-voltage contactors closed, and continue to supply power to or draw power from the high-voltage bus. If the comparison result shows that the total number of faulty clusters is greater than the preset redundancy, the main control BMS determines that the power carrying capacity of the remaining normal clusters in the system is insufficient to meet the minimum requirements for safe operation of the system. At this time, the main control BMS executes the overall high-voltage cutoff strategy, sends a high-voltage cutoff command to the slave control BMS of all battery clusters connected to the high-voltage bus, cuts off all battery clusters from the high-voltage bus, and the entire system shuts down.

[0047] It should be noted that the quantitative judgment mechanism, which compares the total number of faulty clusters with the preset redundancy number, provides a scientific basis for deciding whether the system should continue to operate. This mechanism retains normally operating clusters to the maximum extent within the system's redundancy capacity, improving system availability; and promptly shuts down the entire system when the number of faulty clusters exceeds the redundancy capacity, avoiding safety accidents caused by insufficient power handling.

[0048] Preferably, the main control BMS sends high-voltage disconnection commands to the slave control BMSs of the battery clusters marked as having failed high-voltage access and those that have experienced operational faults. After receiving the high-voltage disconnection command, each slave control BMS controls the high-voltage contactor of the corresponding battery cluster to open, causing the battery cluster to disconnect from the high-voltage bus. The remaining battery clusters that have not received the high-voltage disconnection command keep their high-voltage contactors closed and continue to supply power to the high-voltage bus or draw power from the bus.

[0049] Specifically, when the main control BMS determines that a selective disconnection strategy needs to be implemented, it first generates a list of battery clusters to be disconnected. This list contains the identifiers of all clusters marked as having failed high-voltage access and the identifiers of all clusters that have experienced operational failures. Based on this list, the main control BMS sends a high-voltage disconnection command to the slave control BMS of each battery cluster individually. Upon receiving the high-voltage disconnection command from the main control BMS via the communication bus, each slave control BMS performs its local disconnection operation, controlling the high-voltage contactor of its own battery cluster to disconnect, thus breaking the electrical connection between the positive and negative terminals of the battery cluster and the high-voltage bus, detaching the battery cluster from the high-voltage bus. During the disconnection process, each slave control BMS also performs a discharge operation to release residual charge in its internal capacitors. For other battery clusters not listed in the disconnection list, the main control BMS does not send any high-voltage disconnection commands. The slave control BMSs of these battery clusters maintain their current high-voltage contactor closed state, and the corresponding battery clusters continue to be connected to the high-voltage bus, maintaining normal power supply or drawdown operations.

[0050] It should be noted that the selective disconnection strategy operates only on faulty clusters and does not affect the operation of normal clusters, thus maximizing the power supply continuity of the system while ensuring safety. Each slave control BMS responds independently to its own disconnection command, and the disconnection process does not interfere with each other, resulting in high reliability.

[0051] Preferably, the main control BMS broadcasts a high-voltage disconnection command to the slave control BMSs of all battery clusters connected to the high-voltage bus. After receiving the high-voltage disconnection command, each slave control BMS disconnects the high-voltage contactor of its own battery cluster in a predetermined order, so that all battery clusters are disconnected from the high-voltage bus one by one until all battery clusters are in the high-voltage disconnection state.

[0052] Specifically, when the main control BMS determines that a comprehensive high-voltage disconnection strategy needs to be implemented, the main control BMS simultaneously broadcasts a high-voltage disconnection command to all slave control BMSs of battery clusters connected to the high-voltage bus via the communication bus. Upon receiving the broadcast command, each slave control BMS sequentially performs the disconnection operation of the high-voltage contactor according to a pre-set disconnection sequence in the system. This pre-set disconnection sequence can be based on the battery cluster numbering, the current magnitude of each cluster from smallest to largest, or other system-preset priority sequences.

[0053] In practice, the slave control BMS that is prioritized first controls the high-voltage contactor of its own battery cluster to disconnect. After that cluster is completely disconnected, the slave control BMS that is prioritized next controls the high-voltage contactor of its own cluster to disconnect, and so on, until all connected battery clusters have completed the high-voltage contactor disconnection operation. After all the high-voltage contactors of all battery clusters are disconnected, the entire energy storage system is completely disconnected from the high-voltage bus and is in a high-voltage disconnection state, and the entire system shuts down.

[0054] It should be noted that the overall disconnection command is sent via broadcast, which ensures high communication efficiency and guarantees that all slave BMSs receive the disconnection command simultaneously. Furthermore, each slave BMS disconnects sequentially according to a predetermined order, avoiding the current surge caused by the simultaneous disconnection of all battery clusters. This protects the DC bus and power devices, making the overall power-down process safe and controllable.

[0055] Accordingly, this embodiment also provides a dynamic high-voltage control system based on multiple battery clusters in an energy storage system, including a central control BMS and slave control BMSs respectively set in each battery cluster; the central control BMS is configured to: collect the total voltage of each battery cluster and sort them from high to low; calculate the voltage difference between adjacent clusters, and if any difference is greater than or equal to a set threshold, terminate high-voltage access; if all differences are less than the set threshold, control the corresponding slave control BMS to perform high-voltage access cluster by cluster in order of total voltage from low to high; when any newly accessed cluster fails, the cluster is excluded, and the voltage difference between adjacent clusters of the remaining battery clusters is recalculated and it is determined whether to continue high-voltage access, until all accessible clusters are successful or there are no accessible clusters; count the number of failed high-voltage access clusters and the number of operating faulty clusters, and control the overall high-voltage cut-off when the total number is greater than a preset redundancy number, otherwise only control the cut-off of the corresponding faulty clusters.

[0056] Specifically, the central control BMS, acting as a system-level controller, is responsible for overall high-voltage management decisions and coordinated control. Each slave control BMS, acting as a local controller, is located within its corresponding battery cluster and is responsible for executing commands issued by the central control BMS and reporting local status information. The central control BMS and each slave control BMS are connected via a communication bus to achieve data exchange and command transmission. The central control BMS integrates a data processing module, a comparison and judgment module, a counting and statistics module, and a command generation module. The data processing module receives and sorts the voltage data reported by each slave control BMS. The comparison and judgment module calculates the adjacent voltage difference and compares it with a set threshold, as well as calculates the total number of faulty clusters and compares it with a preset redundancy number. The counting and statistics module accumulates the number of failed access clusters and the number of operating faulty clusters. The command generation module generates corresponding control commands based on the judgment results, including high-voltage access commands and high-voltage disconnection commands sent to each slave control BMS. Each slave control BMS integrates an instruction execution module and a status feedback module. The instruction execution module is responsible for receiving and executing high-voltage access or high-voltage disconnection commands sent by the master control BMS, while the status feedback module is responsible for collecting the operating status of its own battery cluster and reporting it to the master control BMS. During system operation, the master control BMS sequentially performs operations such as voltage acquisition and sorting, differential voltage comparison, cluster-by-cluster access, failure elimination and re-judgment, fault statistics, and availability decision-making according to the process described in the above method claims, realizing full dynamic management of high-voltage access and disconnection of multiple battery clusters.

[0057] It should be noted that this control system achieves an effective combination of centralized decision-making and distributed execution through a hierarchical architecture of a central control BMS and slave control BMSs. The central control BMS is responsible for global logic judgment and strategy decision-making, while the slave control BMS is responsible for local command execution and status reporting. Their roles are clearly defined and they work together to complete the dynamic high-voltage management function of multiple battery clusters in the energy storage system. This system architecture is clear and highly reliable, effectively improving the availability and security of the energy storage system.

[0058] Example 2 This embodiment provides a dynamic high-voltage control method based on multiple battery clusters in an energy storage system, including the following steps: 1. Assume there are N clusters of batteries. Collect the total voltage of each cluster and sort the total voltage of all clusters from highest to lowest. 2. Calculate the voltage difference between two adjacent total voltages and determine if any of the voltage differences is greater than 30V (reference value). If so, do not allow high voltage to be applied to any battery cluster. If all voltage differences are less than 30V, proceed to step 3. 3. Starting with the battery cluster with the lowest total voltage, the main control BMS sends a high voltage command to the slave control BMS of that battery cluster to enable it to reach high voltage. The slave control BMS controls the pre-charging process until the high voltage is successfully reached, and then sends feedback to the main control BMS to confirm the successful high voltage. 4. Repeat step 3 in order of voltage until all battery clusters report a successful high-voltage connection, then report a successful high-voltage connection for the entire energy storage system. 5. If a cluster fails to precharge or experiences other malfunctions during the high-voltage process and is not allowed to be charged to high voltage, the high-voltage failure status will be reported to the main control BMS. 6. After the main control BMS receives the status of high voltage failure, it excludes the cluster, recalculates the voltage difference of the remaining battery clusters, repeats steps 2-4, and counts the total number of battery clusters that failed to reach high voltage, N1. 7. If one or more clusters of batteries fail during normal operation of the system and the high voltage needs to be cut off, then the total number of faulty battery clusters N2 is counted. 8. When N1+N2 is greater than (battery cluster overcurrent fault rate - battery cluster rated operating rate) If the overcurrent fault ratio of the battery cluster is N, the entire system is not allowed to be connected to high voltage. The main control BMS directly sends a high voltage reduction command to make all battery clusters connected to high voltage. If it is less than or equal to N, the main control BMS sends a high voltage reduction command to the corresponding battery cluster, only cutting off the faulty battery cluster, while the remaining battery clusters work normally. 9. After successful high-voltage connection, if high-voltage needs to be de-energized during operation, the main BMS control sends a high-voltage de-energization command to the slave BMS. The high-voltage de-energization command is then sent sequentially according to the battery cluster order. It should be noted that this method can maintain the normal operation of the energy storage system to a certain extent, and will not delay the use of the overall energy storage system due to the failure or damage of individual battery clusters, thereby reducing the economic losses of customers.

[0059] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

[0060] It should be noted that, for the sake of simplicity, the foregoing method embodiments are described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

Claims

1. A dynamic high-voltage control method based on multiple battery clusters in an energy storage system, characterized in that, include: Collect the total voltage of each battery cluster and sort them from highest to lowest; Calculate the voltage difference between adjacent voltages; if any difference is greater than or equal to a set threshold, terminate the high-voltage connection. If all differences are less than the set threshold, high-voltage access will be performed cluster by cluster in order of total voltage from low to high. If any new access cluster fails, it is excluded, and the adjacent voltage difference of the remaining battery clusters is recalculated and it is determined whether high voltage access is possible, until all accessible clusters are successful or no clusters can be accessed. The system counts the number of failed high-voltage clusters and the number of operational fault clusters. If the total number exceeds the preset redundancy limit, the entire high-voltage system is disconnected; otherwise, only the corresponding fault cluster is disconnected.

2. The dynamic high-voltage control method based on multiple battery clusters in an energy storage system according to claim 1, characterized in that, The process of collecting the total voltage of each battery cluster and sorting it from highest to lowest includes: The total voltage value of each battery cluster reported by the slave BMS is obtained by the main control BMS. All the obtained total voltage values ​​are arranged in descending order of value to form a voltage sorting sequence.

3. The dynamic high-voltage control method based on multiple battery clusters in an energy storage system according to claim 1, characterized in that, The calculation of adjacent voltage differences, and termination of high-voltage access if any difference is greater than or equal to a set threshold, includes: The total voltage of the battery clusters in adjacent positions after sorting is calculated by difference to obtain the voltage difference between each adjacent group, and each adjacent voltage difference is compared with a set threshold. If any adjacent voltage difference is greater than or equal to the set threshold, it is determined that the voltage difference between the current battery clusters is too large, and the high-voltage access process of all battery clusters is terminated, and no high-voltage access command is sent to any battery cluster.

4. The dynamic high-voltage control method based on multiple battery clusters in an energy storage system according to claim 1, characterized in that, If all differences are less than a set threshold, then high-voltage access is performed cluster by cluster in order of total voltage from low to high, including: When all adjacent voltage differences are less than a set threshold, the battery cluster with the lowest total voltage is determined from the voltage sorting sequence as the first cluster to be connected. High-voltage access operations are performed on each cluster in ascending order of total voltage. Only one cluster is accessed at any given time. Once the current cluster has completed high-voltage access and the access is confirmed to be successful, the high-voltage access operation is then performed on the next cluster in sequence.

5. The dynamic high-voltage control method based on multiple battery clusters in an energy storage system according to claim 1, characterized in that, If any new access cluster fails, it is excluded, and the adjacent voltage difference of the remaining battery clusters is recalculated and it is determined whether high-voltage access is possible, until all accessible clusters are successfully accessed or no clusters can be accessed, including: During the high-voltage access process, if the battery cluster currently performing the high-voltage access operation fails to precharge or has an access failure, the battery cluster will be marked as an access failure cluster and removed from the voltage sorting sequence, and will not participate in subsequent high-voltage access operations. For the remaining battery clusters to be connected after removing the failed cluster, their total voltages are re-acquired and reordered from high to low; the adjacent voltage differences after reordering are recalculated and compared with a set threshold; if there is a value greater than or equal to the set threshold in the recalculated adjacent voltage differences, the high-voltage connection of all subsequent battery clusters is terminated; if all recalculated adjacent voltage differences are less than the set threshold, the high-voltage connection operation is continued to be performed cluster by cluster starting from the lowest voltage cluster in order of total voltage from low to high after reordering. Repeat the above process of elimination, reordering, recalculating pressure difference, and rejuvenating until all battery clusters that have not experienced connection failures are successfully connected to the high voltage, or the connection of the remaining clusters to be connected is terminated because the pressure difference does not meet the conditions.

6. The dynamic high-voltage control method based on multiple battery clusters in an energy storage system according to claim 1, characterized in that, The statistics on the number of failed clusters and operational fault clusters for high-voltage access failures include: Throughout the entire process from the start of high-voltage access to its completion, the total number of clusters marked as access failures is accumulated to obtain the number of high-voltage access failure clusters. During the period when the high voltage connection is completed and the battery clusters are in normal operation, the operating status of each connected battery cluster is monitored in real time. When any battery cluster experiences an operational failure and the high voltage is disconnected, the cluster is counted as an operational failure cluster to obtain the total number of operational failure clusters.

7. The dynamic high-voltage control method based on multiple battery clusters in an energy storage system according to claim 1, characterized in that, If the total number is greater than the preset redundancy number, the high voltage is completely cut off; otherwise, only the corresponding fault cluster is cut off, including: Calculate the sum of the number of high-voltage access failure clusters and the number of operational fault clusters to obtain the total number of fault clusters; compare the total number of fault clusters with the preset redundancy number; If the total number of faulty clusters is less than or equal to the preset redundancy number, it is determined that the energy storage system still has sufficient redundancy to maintain normal operation. Only the high-voltage access failure clusters and the operating fault clusters are disconnected from the high-voltage bus, while the remaining battery clusters that have been normally connected and have not experienced any faults continue to operate under the high-voltage access status. If the total number of faulty clusters exceeds the preset redundancy, it is determined that the power carrying capacity of the remaining normal clusters in the energy storage system is insufficient to meet the minimum requirements for safe operation of the system. In this case, an overall high-voltage cutoff operation is performed, disconnecting all battery clusters connected to the high-voltage bus from the bus.

8. The dynamic high-voltage control method based on multiple battery clusters in an energy storage system according to claim 7, characterized in that, The method of disconnecting only high-voltage access failure clusters and operational fault clusters from the high-voltage bus includes: The main control BMS sends high-voltage disconnection commands to the slave control BMSs of the battery clusters marked as having failed high-voltage access and those that have experienced operational failures. After receiving the high voltage cut-off command, each slave control BMS controls the high voltage contactor of the corresponding battery cluster to disconnect, so that the battery cluster is disconnected from the high voltage bus. The remaining battery clusters that have not received a high-voltage cutoff command keep their high-voltage contactors closed and continue to supply power to or draw power from the high-voltage bus.

9. The dynamic high-voltage control method based on multiple battery clusters in an energy storage system according to claim 7, characterized in that, The overall high-pressure resection operation includes: The main control BMS broadcasts a high-voltage cut-off command to all slave control BMSs of battery clusters that have been connected to the high-voltage bus. After receiving the high-voltage cutoff command, each slave control BMS disconnects the high-voltage contactor of its respective battery cluster in a predetermined order, so that all battery clusters are disconnected from the high-voltage bus one by one until all battery clusters are in the high-voltage cutoff state.

10. A dynamic high-voltage control system based on a multi-battery cluster in an energy storage system, characterized in that, This includes a central control BMS and slave control BMSs located in each battery cluster; The master control BMS is configured to: collect the total voltage of each battery cluster and sort them from high to low; calculate the voltage difference between adjacent clusters, and if any difference is greater than or equal to a set threshold, terminate high-voltage access; if all differences are less than the set threshold, control the corresponding slave control BMS to perform high-voltage access cluster by cluster in order of total voltage from low to high; when any new access cluster fails, exclude the cluster, recalculate the voltage difference between adjacent clusters of the remaining battery clusters and determine whether to continue high-voltage access, until all accessible clusters are successful or there are no accessible clusters; count the number of failed high-voltage access clusters and the number of faulty operating clusters, and control the overall high-voltage cut-off when the total number is greater than the preset redundancy number, otherwise only control the cut-off of the corresponding faulty clusters.

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