Hierarchical control method and system for parallel battery cluster coordination controller

Abstract

The invention provides a hierarchical control method and system for a parallel battery cluster coordination controller. The method comprises the following steps: monitoring real-time operation data of a parallel battery cluster in real time; judging the system state of the parallel battery cluster according to the DC bus voltage data, wherein the system state is a standby state or a charging and discharging state; if the system state is a standby state, performing circulation elimination control on each battery cluster according to the current data and the voltage data of each battery cluster; if the system state is a charge-discharge state, determining a plurality of first battery clusters not participating in SOC balance control and a plurality of second battery clusters participating in SOC balance control according to the current data of each battery cluster; performing current direction control and current size control on each first battery cluster according to the current data of each battery cluster; and performing SOC balance control on each second battery cluster according to the SOC value of each battery cluster. The operation safety and the energy utilization efficiency of the parallel battery clusters are improved.

Description

Technical Field

[0001] This application relates to the fields of battery energy storage and battery control technology, and in particular to a data transmission control method and system for power systems. Background Technology

[0002] In battery energy storage systems, multiple battery clusters connected in parallel can meet the demands for high-power, large-capacity energy storage. However, due to factors such as battery manufacturing processes and operating environments, inconsistencies exist between different battery clusters, such as inconsistent state of charge (SOC) and different internal resistances. These inconsistencies can lead to circulating currents during the charging and discharging process. These circulating currents not only increase system energy loss but may also accelerate battery aging, reduce battery lifespan, and even affect the safety and stability of the entire energy storage system.

[0003] Currently, control strategies for parallel battery clusters mainly focus on circulating current suppression and SOC equalization. However, in practical applications, these algorithms often cannot simultaneously meet multiple control objectives. For example, while ensuring SOC equalization, it is difficult to ensure that the output current of all battery clusters is in the same direction, and it is also difficult to effectively control the voltage output of the cluster optimizer to reduce power loss. For instance, although topologies based on bidirectional DC / DC converters can improve equalization speed, it is difficult to simultaneously optimize current direction control and SOC equalization under dynamic operating conditions, and complex algorithms increase implementation costs and system complexity. In addition, traditional centralized architectures are susceptible to the "weakest link" effect due to the direct parallel connection of battery clusters, while distributed architectures, although mitigating circulating current through DC / DC isolation, suffer from efficiency degradation due to multi-stage energy conversion.

[0004] While recent research has made progress in topology innovation and algorithm optimization, it still lacks a hierarchical collaborative mechanism for all operating conditions. For example, the circulating current suppression strategy in the standby phase and the SOC equalization control in the charging and discharging phase are often designed independently, resulting in a fragmentation of the global optimization objective; and voltage optimization strategies mostly use static thresholds, without considering the dynamic coupling effect of multi-dimensional constraints such as temperature and current. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a hierarchical control method and system for a parallel battery cluster coordination controller, which improves the operational safety and energy utilization efficiency of the parallel battery cluster.

[0006] In a first aspect, embodiments of this application provide a hierarchical control method for a parallel battery cluster coordination controller, comprising:

[0007] Real-time monitoring of the real-time operating data of parallel battery clusters, including DC bus voltage data, current data, voltage data and SOC value of each battery cluster;

[0008] The system state of the parallel battery cluster is determined based on the DC bus voltage data, and the system state is either standby state or charging / discharging state.

[0009] If the system is in standby mode, then circulating current elimination control is performed on each battery cluster based on the current and voltage data of each battery cluster.

[0010] If the system is in a charging / discharging state, then based on the current data of each battery cluster, a number of first battery clusters that do not participate in SOC equalization control and a number of second battery clusters that participate in SOC equalization control are determined.

[0011] The current direction and magnitude of each of the first battery clusters are controlled based on the current data of each battery cluster.

[0012] SOC equalization control is performed on each of the second battery clusters based on the SOC value of each of the battery clusters.

[0013] This application provides a hierarchical control method for a parallel battery cluster coordination controller. By monitoring the real-time operating data of the parallel battery clusters, the system state of the parallel battery clusters is determined. Based on different system states, hierarchical control is applied to each battery cluster within the parallel battery cluster, achieving targeted control at different stages and improving the operational safety and energy utilization efficiency of the parallel battery clusters. Specifically, in standby mode, the main objective of the coordination controller is to ensure no circulating current between battery clusters, avoiding increased energy loss due to circulating current. Therefore, circulating current elimination control is performed on each battery cluster to improve energy utilization efficiency and extend battery life. State of Charge (SOC) balancing is not considered at this stage to reduce unnecessary energy consumption and control complexity. In charge / discharge mode, operational safety of the parallel battery clusters is prioritized. Therefore, each battery cluster is first classified based on current data. Then, current direction and magnitude control are applied to the first battery cluster to ensure operational safety. SOC balancing control is applied to the second battery cluster, achieving balanced charge and discharge of the battery clusters, improving the available capacity and efficiency of the entire energy storage system, and resolving the problem of battery cluster inconsistency. In addition, the hierarchical control mechanism effectively reduces redundant operations. For example, in the charging and discharging state, only the second battery cluster is subjected to SOC balancing, avoiding the problem of inconsistent current direction of battery clusters and SOC balancing at the same time, thus improving the coordination control efficiency of parallel battery clusters.

[0014] Furthermore, the circulating current elimination control for each battery cluster based on the current and voltage data of each battery cluster includes:

[0015] The current is adjusted several times for each of the battery clusters until the current difference between the battery clusters is less than or equal to a first preset threshold or the system state is switched to charging and discharging state.

[0016] In each current adjustment process, the current difference and voltage difference between each battery cluster are calculated based on the current and voltage data of each battery cluster, and the target battery cluster pair corresponding to the maximum current difference is determined. If the current difference of the target battery cluster pair is greater than a first preset threshold, the output voltage of the low-current battery cluster in the target battery cluster pair is increased by a first voltage value, and the output voltage of the high-current battery cluster in the target battery cluster pair is decreased by a first voltage value. The first voltage value is the product of the voltage difference of the target battery cluster pair and a preset first adjustment coefficient.

[0017] This application provides a circulating current elimination control method. By iteratively adjusting the output voltage of the battery clusters, using the product of the voltage difference and a preset coefficient as the adjustment amount, the current difference is rapidly converged, avoiding the oscillation problem caused by excessive or insufficient adjustment amplitude in traditional methods. Furthermore, in each adjustment process, only the target battery cluster pair corresponding to the maximum current difference is adjusted. A "target battery cluster pair" selection strategy is adopted, prioritizing the battery cluster pair with the maximum current difference, reducing interference to other battery clusters, and improving control accuracy.

[0018] In one possible implementation, determining a plurality of first battery clusters that do not participate in SOC equalization control and a plurality of second battery clusters that participate in SOC equalization control based on the current data of each of the battery clusters includes:

[0019] The direction of the total current of the parallel battery clusters is determined based on the current data of each battery cluster.

[0020] Traverse each of the battery clusters and determine each of the battery clusters as either the first battery cluster or the second battery cluster;

[0021] During the traversal process, if the current direction of any current battery cluster is opposite to the total current direction, or if the current value of the current battery cluster is greater than a second preset threshold, then the current battery cluster is determined to be the first battery cluster; otherwise, the current battery cluster is determined to be the second battery cluster.

[0022] This application provides a battery cluster classification method. First battery clusters are selected based on the consistency of the current direction of each cluster with the overall direction and the current threshold. These first battery clusters have issues with reverse current or current overload. Therefore, the abnormal current direction and magnitude of the first battery clusters need to be addressed first to ensure the operational safety of the parallel battery clusters. For the second battery clusters, the current direction is consistent and the current magnitude is within a safe range. SOC balancing can be further considered to improve the energy utilization efficiency of the parallel battery clusters. This application classifies battery clusters by judging the current direction and magnitude. This avoids abnormal battery clusters from participating in SOC balancing, reducing the risk of cascading failures. Classification also reduces the number of battery clusters participating in SOC balancing, lowering the computational load and improving the real-time performance of control.

[0023] Furthermore, the step of controlling the current direction and magnitude of each of the first battery clusters based on the current data of each battery cluster includes:

[0024] Within a preset control time period, each of the first battery clusters is cyclically traversed, and the current direction and current magnitude of each of the first battery clusters are adjusted.

[0025] During the cyclic traversal, for any current first battery cluster, the current direction and current value of the current first battery cluster are determined based on the current data of the current first battery cluster.

[0026] If the current direction of the current in the current first battery cluster is opposite to the total current direction, then the output voltage of the current first battery cluster is increased or decreased by a preset second voltage value according to the total current direction.

[0027] If the current value of the current first battery cluster is greater than the second preset threshold, then the current of the current first battery cluster is determined to be excessive, and the output voltage of the current first battery cluster is reduced by a third voltage value, wherein the third voltage value is the product between the current excessive value of the current first battery cluster and a preset second adjustment coefficient.

[0028] If the current direction of the current in the current first battery cluster is the same as the total current direction, and the current value of the current first battery cluster is less than or equal to the second preset threshold, then the current first battery cluster is converted into the second battery cluster.

[0029] This application provides a method for controlling a first battery cluster. By iteratively adjusting the current direction or value of each first battery cluster, the method addresses reverse current adjustment by repeatedly increasing or decreasing a preset second voltage value to change the current direction of the first battery cluster. This avoids sudden current changes caused by excessively large adjustments at once, ultimately ensuring that the output current of all battery clusters is in the same direction, reducing circulating current losses between battery clusters, and improving system stability and safety. For overload current adjustment, a third voltage value is determined by calculating the current exceeding the limit of the current in the current of the first battery cluster, enabling targeted and precise adjustment. This quickly reduces the current value to a safe range, protecting the battery clusters from damage caused by excessive current and extending battery life. Finally, by converting a first battery cluster that meets the requirements into a second battery cluster, battery clusters without safety issues can be promptly added to the SOC equalization control, further improving the energy utilization efficiency of parallel battery clusters.

[0030] Furthermore, the step of performing SOC balancing control on each of the second battery clusters based on the SOC value of each of the battery clusters includes:

[0031] Within a preset control time period, the SOC of each second battery cluster is adjusted several times.

[0032] In each SOC adjustment process, the average SOC value is calculated based on the SOC value of each battery cluster, and then the SOC difference between the SOC value of each battery cluster and the average SOC value is calculated. The output voltage of each second battery cluster is increased or decreased by a corresponding fourth voltage value, which is the product of the SOC difference of the corresponding second battery cluster and a preset third adjustment coefficient.

[0033] This application provides a SOC equalization control method. By introducing the average SOC value as the SOC equalization control benchmark, the SOC values ​​of each battery cluster are made to converge through several SOC adjustments, avoiding current surges caused by excessively large adjustments in a single step. During each adjustment, the product of the SOC difference of each battery cluster and the adjustment coefficient is calculated to determine the fourth voltage value of each battery cluster. Based on these fourth voltage values, the output voltage of each battery cluster is adjusted accordingly, achieving precise SOC equalization control.

[0034] In one possible implementation, the hierarchical control method further includes global power consumption control for each of the battery clusters, including:

[0035] Based on the voltage data of each battery cluster, determine the third battery cluster with the minimum output voltage;

[0036] If the output voltage of the third battery cluster is greater than the third preset threshold, then the output voltage of each battery cluster is reduced by a fifth voltage value, which is the difference between the output voltage of the target battery cluster and the third preset threshold.

[0037] This application further introduces global power consumption control, using the third battery cluster with the minimum output voltage and the third preset threshold as the standard. While ensuring that the energy supply of the parallel battery clusters is not affected, the output voltage of all battery clusters is reduced at the same time, which reduces power loss, improves the energy utilization efficiency of the system, and also avoids the parallel battery clusters from operating under high voltage for a long time, thus extending the battery life.

[0038] In one possible implementation, the hierarchical control method further includes global temperature control of each of the battery clusters, including:

[0039] Real-time monitoring of the ambient temperature and total output current of the parallel battery cluster;

[0040] The current voltage limit of the parallel battery cluster is determined based on the preset temperature / current-voltage upper limit curve.

[0041] Based on the voltage data of each battery cluster, determine a number of fourth battery clusters whose output voltage is greater than the current voltage upper limit;

[0042] Reduce the output voltage of each of the fourth battery clusters to the current voltage upper limit.

[0043] This application further introduces global temperature control, which dynamically adjusts the current voltage limit based on the temperature / current-voltage curve, the current ambient temperature, and the total output current, and limits the voltage output of each battery cluster according to the current voltage limit, thus ensuring the safe and stable operation of the parallel battery clusters under various operating conditions.

[0044] Secondly, embodiments of this application provide a hierarchical control system for a parallel battery cluster coordination controller, including a monitoring module, a first judgment module, a circulating current elimination module, a second judgment module, a current control module, and a SOC control module;

[0045] The monitoring module is used to monitor the real-time operating data of the parallel battery clusters. The real-time operating data includes DC bus voltage data, current data, voltage data and SOC value of each battery cluster.

[0046] The first judgment module is used to determine the system state of the parallel battery cluster based on the DC bus voltage data, wherein the system state is standby state or charging / discharging state;

[0047] The circulating current elimination module is used to perform circulating current elimination control on each battery cluster based on the current and voltage data of each battery cluster if the system is in standby mode.

[0048] The second judgment module is used to determine, based on the current data of each battery cluster, a number of first battery clusters that do not participate in SOC equalization control and a number of second battery clusters that participate in SOC equalization control if the system state is in a charging and discharging state.

[0049] The current control module is used to control the current direction and current magnitude of each of the first battery clusters based on the current data of each battery cluster.

[0050] The SOC control module is used to perform SOC equalization control on each of the second battery clusters based on the SOC value of each of the battery clusters.

[0051] In one possible implementation, the circulating current elimination module performs circulating current elimination control on each battery cluster based on the current and voltage data of each battery cluster, including:

[0052] The current is adjusted several times for each of the battery clusters until the current difference between the battery clusters is less than or equal to a first preset threshold or the system state is switched to charging and discharging state.

[0053] In each current adjustment process, the current difference and voltage difference between each battery cluster are calculated based on the current and voltage data of each battery cluster, and the target battery cluster pair corresponding to the maximum current difference is determined. If the current difference of the target battery cluster pair is greater than a first preset threshold, the output voltage of the low-current battery cluster in the target battery cluster pair is increased by a first voltage value, and the output voltage of the high-current battery cluster in the target battery cluster pair is decreased by a first voltage value. The first voltage value is the product of the voltage difference of the target battery cluster pair and a preset first adjustment coefficient.

[0054] In one possible implementation, the second determining module determines, based on the current data of each battery cluster, a plurality of first battery clusters that do not participate in SOC equalization control and a plurality of second battery clusters that participate in SOC equalization control, including:

[0055] The direction of the total current of the parallel battery clusters is determined based on the current data of each battery cluster.

[0056] Traverse each of the battery clusters and determine each of the battery clusters as either the first battery cluster or the second battery cluster;

[0057] During the traversal process, if the current direction of any current battery cluster is opposite to the total current direction, or if the current value of the current battery cluster is greater than a second preset threshold, then the current battery cluster is determined to be the first battery cluster; otherwise, the current battery cluster is determined to be the second battery cluster. Attached Figure Description

[0058] Figure 1 A schematic flowchart illustrating a hierarchical control method for a parallel battery cluster coordination controller, provided as an embodiment of this application;

[0059] Figure 2 A schematic diagram of the system structure of a parallel battery cluster in a hierarchical control method for a parallel battery cluster coordination controller provided in an embodiment of this application;

[0060] Figure 3 Another schematic flowchart of a hierarchical control method for a parallel battery cluster coordination controller provided in an embodiment of this application;

[0061] Figure 4 This is a schematic diagram of a hierarchical control system for a parallel battery cluster coordination controller, provided as an embodiment of this application. Detailed Implementation

[0062] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0063] It should be noted that the step numbers in this document are only for the convenience of explaining the specific embodiments and are not intended to limit the order in which the steps are performed. In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0064] Example 1:

[0065] like Figure 1 As shown, Embodiment 1 provides a hierarchical control method for a parallel battery cluster coordination controller, including steps S1-S6:

[0066] Step S1: Monitor the real-time operating data of the parallel battery clusters. The real-time operating data includes DC bus voltage data, current data, voltage data, and SOC value of each battery cluster.

[0067] Step S2: Determine the system state of the parallel battery cluster based on the DC bus voltage data. The system state is either standby or charging / discharging.

[0068] Step S3: If the system is in standby mode, then perform circulating current elimination control on each battery cluster based on the current and voltage data of each battery cluster.

[0069] Step S4: If the system is in a charging / discharging state, then determine a number of first battery clusters that do not participate in SOC equalization control and a number of second battery clusters that participate in SOC equalization control based on the current data of each battery cluster.

[0070] Step S5: Control the current direction and current magnitude of each of the first battery clusters according to the current data of each battery cluster.

[0071] Step S6: Perform SOC equalization control on each of the second battery clusters according to the SOC value of each battery cluster.

[0072] This application provides a hierarchical control method for a parallel battery cluster coordination controller. By monitoring the real-time operating data of the parallel battery clusters, the system state of the parallel battery clusters is determined. Based on different system states, hierarchical control is applied to each battery cluster within the parallel battery cluster, achieving targeted control at different stages and improving the operational safety and energy utilization efficiency of the parallel battery clusters. Specifically, in standby mode, the main objective of the coordination controller is to ensure no circulating current between battery clusters, avoiding increased energy loss due to circulating current. Therefore, circulating current elimination control is performed on each battery cluster to improve energy utilization efficiency and extend battery life. State of Charge (SOC) balancing is not considered at this stage to reduce unnecessary energy consumption and control complexity. In charge / discharge mode, operational safety of the parallel battery clusters is prioritized. Therefore, each battery cluster is first classified based on current data. Then, current direction and magnitude control are applied to the first battery cluster to ensure operational safety. SOC balancing control is applied to the second battery cluster, achieving balanced charge and discharge of the battery clusters, improving the available capacity and efficiency of the entire energy storage system, and resolving the problem of battery cluster inconsistency. In addition, the hierarchical control mechanism effectively reduces redundant operations. For example, in the charging and discharging state, only the second battery cluster is subjected to SOC balancing, avoiding the problem of inconsistent current direction of battery clusters and SOC balancing at the same time, thus improving the coordination control efficiency of parallel battery clusters.

[0073] In a preferred embodiment, Figure 2 This is a schematic diagram of the system structure of a parallel battery cluster provided in an embodiment of the present invention. Figure 2As shown, the system comprises n battery clusters (cell cluster 1 to cell cluster n), each connected to a cluster optimizer (cluster optimizer 1 to cluster optimizer n). Each cluster optimizer possesses dual closed-loop control capability for both voltage and current. The outputs of all cluster optimizers are connected in parallel to a main DC bus, which in turn connects to an external converter. The coordinating controller can acquire the electrical parameters (voltage, current, SOC) and ambient temperature of each battery cluster in real time via the CAN bus. Based on a hierarchical control strategy, it generates control signals and sends them to each cluster optimizer, dynamically adjusting the output voltage of the cluster optimizer to achieve multi-objective coordinated control.

[0074] Furthermore, in step S3, the circulating current elimination control of each battery cluster based on the current and voltage data of each battery cluster includes:

[0075] The current is adjusted several times for each of the battery clusters until the current difference between the battery clusters is less than or equal to a first preset threshold or the system state is switched to charging and discharging state.

[0076] In each current adjustment process, the current difference and voltage difference between each battery cluster are calculated based on the current and voltage data of each battery cluster, and the target battery cluster pair corresponding to the maximum current difference is determined. If the current difference of the target battery cluster pair is greater than a first preset threshold, the output voltage of the low-current battery cluster in the target battery cluster pair is increased by a first voltage value, and the output voltage of the high-current battery cluster in the target battery cluster pair is decreased by a first voltage value. The first voltage value is the product of the voltage difference of the target battery cluster pair and a preset first adjustment coefficient.

[0077] This application provides a circulating current elimination control method. By iteratively adjusting the output voltage of the battery clusters, using the product of the voltage difference and a preset coefficient as the adjustment amount, the current difference is rapidly converged, avoiding the oscillation problem caused by excessive or insufficient adjustment amplitude in traditional methods. Furthermore, in each adjustment process, only the target battery cluster pair corresponding to the maximum current difference is adjusted. A "target battery cluster pair" selection strategy is adopted, prioritizing the battery cluster pair with the maximum current difference, reducing interference to other battery clusters, and improving control accuracy.

[0078] In a preferred embodiment, during the circulating current elimination control phase, the coordinating controller calculates the current difference ΔI between each battery cluster. ij =I i -I j (i≠j). Set the current difference threshold (i.e., the first preset threshold) I. th =0.5A. When the maximum current difference max{|ΔI} is detected. ij |}>I thFor example, the current difference |ΔI between battery cluster 1 and battery cluster 2. 12 |=0.5A>I th Then adjust the cluster optimizer output voltage of either battery cluster 1 or battery cluster 2. Assume the cluster optimizer output voltage of battery cluster 1 is V. opt1 The cluster optimizer output voltage of battery cluster 2 is V. opt2 And I1>I2, then according to the formula (where K) i (The value is a current adjustment coefficient, which can be 0.1). The new output voltages of battery cluster 1 and battery cluster 2 are then calculated. The current is output and then adjusted again until the current difference between all battery clusters meets the threshold requirement, thereby achieving no circulating current between battery clusters.

[0079] In one possible implementation, step S4, determining the first battery clusters that do not participate in SOC equalization control and the second battery clusters that participate in SOC equalization control based on the current data of each of the battery clusters, includes:

[0080] The direction of the total current of the parallel battery clusters is determined based on the current data of each battery cluster.

[0081] Traverse each of the battery clusters and determine each of the battery clusters as either the first battery cluster or the second battery cluster;

[0082] During the traversal process, if the current direction of any current battery cluster is opposite to the total current direction, or if the current value of the current battery cluster is greater than a second preset threshold, then the current battery cluster is determined to be the first battery cluster; otherwise, the current battery cluster is determined to be the second battery cluster.

[0083] This application provides a battery cluster classification method. First battery clusters are selected based on the consistency of the current direction of each cluster with the overall direction and the current threshold. These first battery clusters have issues with reverse current or current overload. Therefore, the abnormal current direction and magnitude of the first battery clusters need to be addressed first to ensure the operational safety of the parallel battery clusters. For the second battery clusters, the current direction is consistent and the current magnitude is within a safe range. SOC balancing can be further considered to improve the energy utilization efficiency of the parallel battery clusters. This application classifies battery clusters by judging the current direction and magnitude. This avoids abnormal battery clusters from participating in SOC balancing, reducing the risk of cascading failures. Classification also reduces the number of battery clusters participating in SOC balancing, lowering the computational load and improving the real-time performance of control.

[0084] Furthermore, in step S5, the step of controlling the current direction and magnitude of each of the first battery clusters based on the current data of each battery cluster includes:

[0085] Within a preset control time period, each of the first battery clusters is cyclically traversed, and the current direction and current magnitude of each of the first battery clusters are adjusted.

[0086] During the cyclic traversal, for any current first battery cluster, the current direction and current value of the current first battery cluster are determined based on the current data of the current first battery cluster.

[0087] If the current direction of the current in the current first battery cluster is opposite to the total current direction, then the output voltage of the current first battery cluster is increased or decreased by a preset second voltage value according to the total current direction.

[0088] If the current value of the current first battery cluster is greater than the second preset threshold, then the current of the current first battery cluster is determined to be excessive, and the output voltage of the current first battery cluster is reduced by a third voltage value, wherein the third voltage value is the product between the current excessive value of the current first battery cluster and a preset second adjustment coefficient.

[0089] If the current direction of the current in the current first battery cluster is the same as the total current direction, and the current value of the current first battery cluster is less than or equal to the second preset threshold, then the current first battery cluster is converted into the second battery cluster.

[0090] This application provides a method for controlling a first battery cluster. By iteratively adjusting the current direction or value of each first battery cluster, the method addresses reverse current adjustment by repeatedly increasing or decreasing a preset second voltage value to change the current direction of the first battery cluster. This avoids sudden current changes caused by excessively large adjustments at once, ultimately ensuring that the output current of all battery clusters is in the same direction, reducing circulating current losses between battery clusters, and improving system stability and safety. For overload current adjustment, a third voltage value is determined by calculating the current exceeding the limit of the current in the current of the first battery cluster, enabling targeted and precise adjustment. This quickly reduces the current value to a safe range, protecting the battery clusters from damage caused by excessive current and extending battery life. Finally, by converting a first battery cluster that meets the requirements into a second battery cluster, battery clusters without safety issues can be promptly added to the SOC equalization control, further improving the energy utilization efficiency of parallel battery clusters.

[0091] In a preferred embodiment, the control of the first battery cluster includes output current direction control and output current maximum value limitation, as detailed below:

[0092] Output current direction control: Real-time monitoring of the current direction of each first battery cluster. Assuming the current direction (charging) of battery cluster 5 is opposite to the overall output current direction (discharging), the current direction is changed by adjusting the output voltage of its cluster optimizer. Based on the characteristics of the cluster optimizer, the output voltage of battery cluster 5 is increased to make the current increment positive, thereby changing the current direction. The specific adjustment amount can be determined according to the actual situation, for example, increasing or decreasing by 0.1V each time, until the current direction is the same as that of other battery clusters. At the same time, battery cluster 5 temporarily does not participate in SOC equalization.

[0093] Output current maximum limit: Real-time monitoring of the output current I of each first battery cluster i Assuming the output current of battery cluster 6 is I6 = 50A, and the maximum set limit is I... max =40A, then reduce the output voltage of the cluster optimizer of battery cluster 6. According to the formula (where K) lim The current limiting adjustment factor is set, and the current unit is converted to the voltage unit (a value of 0.05 can be used to calculate the new output voltage). And output, until I6≤I max Meanwhile, battery cluster 6 will not participate in SOC balancing for the time being.

[0094] When the output current direction of battery cluster 5 or battery cluster 6 is the same as the total output current direction, and the output current is less than or equal to the maximum value limit I. max In this case, either battery cluster 5 or battery cluster 6 can participate in SOC balancing.

[0095] Furthermore, in step S6, the SOC balancing control of each of the second battery clusters based on the SOC value of each battery cluster includes:

[0096] Within a preset control time period, the SOC of each second battery cluster is adjusted several times.

[0097] In each SOC adjustment process, the average SOC value is calculated based on the SOC value of each battery cluster, and then the SOC difference between the SOC value of each battery cluster and the average SOC value is calculated. The output voltage of each second battery cluster is increased or decreased by a corresponding fourth voltage value, which is the product of the SOC difference of the corresponding second battery cluster and a preset third adjustment coefficient.

[0098] This application provides a SOC equalization control method. By introducing the average SOC value as the SOC equalization control benchmark, the SOC values ​​of each battery cluster are made to converge through several SOC adjustments, avoiding current surges caused by excessively large adjustments in a single step. During each adjustment, the product of the SOC difference of each battery cluster and the adjustment coefficient is calculated to determine the fourth voltage value of each battery cluster. Based on these fourth voltage values, the output voltage of each battery cluster is adjusted accordingly, achieving precise SOC equalization control.

[0099] In a preferred embodiment, the specific process of performing SOC equalization control on each second battery cluster is as follows:

[0100] Calculate the average SOC of all second battery clusters Assuming the SOC of battery cluster 3 is SOC3 = 0.8, SOC ave =0.7, then ΔSOC3 = SOC3 - SOC ave =0.1>0. At this time, reduce the output voltage of the cluster optimizer of battery cluster 3, according to the formula (where K) soc Assign a SOC adjustment factor and convert the SOC unit to voltage unit (a value of 0.2 is acceptable) to calculate the new output voltage. This outputs a signal that slows down the charging speed or accelerates the discharging speed of battery cluster 3. Simultaneously, it affects ΔSOC. i For battery clusters with a voltage <0, such as battery cluster 4 with ΔSOC4 = -0.1, the output voltage of its cluster optimizer should be reduced. This accelerates the charging speed or slows down the discharging speed of battery cluster 4. Through continuous cyclic adjustments, the SOC of each battery cluster is brought closer to uniformity.

[0101] In one possible implementation, the hierarchical control method further includes global power consumption control for each of the battery clusters, including:

[0102] Based on the voltage data of each battery cluster, determine the third battery cluster with the minimum output voltage;

[0103] If the output voltage of the third battery cluster is greater than the third preset threshold, then the output voltage of each battery cluster is reduced by a fifth voltage value, which is the difference between the output voltage of the target battery cluster and the third preset threshold.

[0104] This application further introduces global power consumption control, using the third battery cluster with the minimum output voltage and the third preset threshold as the standard. While ensuring that the energy supply of the parallel battery clusters is not affected, the output voltage of all battery clusters is reduced at the same time, which reduces power loss, improves the energy utilization efficiency of the system, and also avoids the parallel battery clusters from operating under high voltage for a long time, thus extending the battery life.

[0105] In a preferred embodiment, the specific process of global power consumption control for each battery cluster is as follows:

[0106] Monitor the output voltage of each cluster optimizer in real time to identify the cluster optimizer with the lowest output voltage. Assume the output voltage of cluster optimizer 7 is V. opt7 =15V, the lowest among all cluster optimizers; the minimum allowable output voltage for the cluster optimizer itself is 10V. At this point, the output voltages of all cluster optimizers are gradually and simultaneously reduced by the same magnitude, for example, by 0.5V each time, until the output voltage V of cluster optimizer 7 is reached. opt7 =V opt-min =10V, to minimize the output voltage of all cluster optimizers while ensuring that other control objectives are not affected.

[0107] In one possible implementation, the hierarchical control method further includes global temperature control of each of the battery clusters, including:

[0108] Real-time monitoring of the ambient temperature and total output current of the parallel battery cluster;

[0109] The current voltage limit of the parallel battery cluster is determined based on the preset temperature / current-voltage upper limit curve.

[0110] Based on the voltage data of each battery cluster, determine a number of fourth battery clusters whose output voltage is greater than the current voltage upper limit;

[0111] Reduce the output voltage of each of the fourth battery clusters to the current voltage upper limit.

[0112] This application further introduces global temperature control, which dynamically adjusts the current voltage limit based on the temperature / current-voltage curve, the current ambient temperature, and the total output current, and limits the voltage output of each battery cluster according to the current voltage limit, thus ensuring the safe and stable operation of the parallel battery clusters under various operating conditions.

[0113] In a preferred embodiment, the specific process of global temperature control for each battery cluster is as follows:

[0114] Obtain the ambient temperature of the battery stack T = 35°C and the total output current I of the battery stack. o =100A, based on the preset temperature / current-voltage upper limit curve Vmax (T,I o Find the upper limit of the cluster optimizer's voltage output V at the current temperature. max (35°, 100A) = 35V. Assume the output voltage V of cluster optimizer 8 is... opt8 >V max (35°, 100A), then according to the formula Determine the new output voltage of cluster optimizer 8

[0115] like Figure 3 As shown, this embodiment of the application determines the system state of the parallel battery clusters by real-time monitoring of their operational data, and implements standby circulating current suppression strategies or multi-constraint management strategies based on the system state. Simultaneously, regardless of the system state, a global voltage optimization strategy is implemented for each battery cluster, including global power consumption control and global temperature control. Therefore, the hierarchical control method proposed in this embodiment includes three core strategies: standby circulating current suppression strategy, charge / discharge multi-constraint management strategy, and global voltage optimization strategy. The charge / discharge control follows a "safety first" principle, executing in the priority order of current direction correction → current limit protection → SOC equalization.

[0116] Example 2:

[0117] like Figure 4 As shown, Embodiment 2 provides a hierarchical control system for a parallel battery cluster coordination controller, including a monitoring module 10, a first judgment module 20, a circulating current elimination module 30, a second judgment module 40, a current control module 50, and a SOC control module 60.

[0118] The monitoring module 10 is used to monitor the real-time operating data of the parallel battery clusters. The real-time operating data includes DC bus voltage data, current data, voltage data and SOC value of each battery cluster.

[0119] The first judgment module 20 is used to determine the system state of the parallel battery cluster based on the DC bus voltage data, wherein the system state is standby state or charging / discharging state;

[0120] The circulating current elimination module 30 is used to perform circulating current elimination control on each battery cluster based on the current data and voltage data of each battery cluster if the system state is standby.

[0121] The second judgment module 40 is used to determine, based on the current data of each battery cluster, a number of first battery clusters that do not participate in SOC equalization control and a number of second battery clusters that participate in SOC equalization control if the system state is a charging and discharging state.

[0122] The current control module 50 is used to control the current direction and current magnitude of each of the first battery clusters based on the current data of each battery cluster.

[0123] The SOC control module 60 is used to perform SOC equalization control on each of the second battery clusters according to the SOC value of each of the battery clusters.

[0124] In one possible implementation, the circulating current elimination module 30 performs circulating current elimination control on each battery cluster based on the current and voltage data of each battery cluster, including:

[0125] The current is adjusted several times for each of the battery clusters until the current difference between the battery clusters is less than or equal to a first preset threshold or the system state is switched to charging and discharging state.

[0126] In each current adjustment process, the current difference and voltage difference between each battery cluster are calculated based on the current and voltage data of each battery cluster, and the target battery cluster pair corresponding to the maximum current difference is determined. If the current difference of the target battery cluster pair is greater than a first preset threshold, the output voltage of the low-current battery cluster in the target battery cluster pair is increased by a first voltage value, and the output voltage of the high-current battery cluster in the target battery cluster pair is decreased by a first voltage value. The first voltage value is the product of the voltage difference of the target battery cluster pair and a preset first adjustment coefficient.

[0127] In one possible implementation, the second determining module 40 determines, based on the current data of each battery cluster, a plurality of first battery clusters that do not participate in SOC equalization control and a plurality of second battery clusters that participate in SOC equalization control, including:

[0128] The direction of the total current of the parallel battery clusters is determined based on the current data of each battery cluster.

[0129] Traverse each of the battery clusters and determine each of the battery clusters as either the first battery cluster or the second battery cluster;

[0130] During the traversal process, if the current direction of any current battery cluster is opposite to the total current direction, or if the current value of the current battery cluster is greater than a second preset threshold, then the current battery cluster is determined to be the first battery cluster; otherwise, the current battery cluster is determined to be the second battery cluster.

[0131] Furthermore, the current control module 50 performs current direction control and current magnitude control on each of the first battery clusters based on the current data of each battery cluster, including:

[0132] Within a preset control time period, each of the first battery clusters is cyclically traversed, and the current direction and current magnitude of each of the first battery clusters are adjusted.

[0133] During the cyclic traversal, for any current first battery cluster, the current direction and current value of the current first battery cluster are determined based on the current data of the current first battery cluster.

[0134] If the current direction of the current in the current first battery cluster is opposite to the total current direction, then the output voltage of the current first battery cluster is increased or decreased by a preset second voltage value according to the total current direction.

[0135] If the current value of the current first battery cluster is greater than the second preset threshold, then the current of the current first battery cluster is determined to be excessive, and the output voltage of the current first battery cluster is reduced by a third voltage value, wherein the third voltage value is the product between the current excessive value of the current first battery cluster and a preset second adjustment coefficient.

[0136] If the current direction of the current in the current first battery cluster is the same as the total current direction, and the current value of the current first battery cluster is less than or equal to the second preset threshold, then the current first battery cluster is converted into the second battery cluster.

[0137] Furthermore, the SOC control module 60 performs SOC balancing control on each of the second battery clusters based on the SOC value of each battery cluster, including:

[0138] Within a preset control time period, the SOC of each second battery cluster is adjusted several times.

[0139] In each SOC adjustment process, the average SOC value is calculated based on the SOC value of each battery cluster, and then the SOC difference between the SOC value of each battery cluster and the average SOC value is calculated. The output voltage of each second battery cluster is increased or decreased by a corresponding fourth voltage value, which is the product of the SOC difference of the corresponding second battery cluster and a preset third adjustment coefficient.

[0140] In one possible implementation, the hierarchical control system further includes a global power consumption control module, which is used to perform global power consumption control on each of the battery clusters, specifically:

[0141] Based on the voltage data of each battery cluster, determine the third battery cluster with the minimum output voltage;

[0142] If the output voltage of the third battery cluster is greater than the third preset threshold, then the output voltage of each battery cluster is reduced by a fifth voltage value, which is the difference between the output voltage of the target battery cluster and the third preset threshold.

[0143] In one possible implementation, the hierarchical control system further includes a global temperature control module for performing global temperature control on each of the battery clusters, including:

[0144] Real-time monitoring of the ambient temperature and total output current of the parallel battery cluster;

[0145] The current voltage limit of the parallel battery cluster is determined based on the preset temperature / current-voltage upper limit curve.

[0146] Based on the voltage data of each battery cluster, determine a number of fourth battery clusters whose output voltage is greater than the current voltage upper limit;

[0147] Reduce the output voltage of each of the fourth battery clusters to the current voltage upper limit.

[0148] This application provides a hierarchical control system for a parallel battery cluster coordination controller. By monitoring the real-time operating data of the parallel battery clusters, the system state of the parallel battery clusters is determined. Based on different system states, hierarchical control is performed on each battery cluster within the parallel battery cluster, achieving targeted control at different stages and improving the operational safety and energy utilization efficiency of the parallel battery clusters. Specifically, in standby mode, the main objective of the coordination controller is to ensure no circulating current between battery clusters, avoiding increased energy loss due to circulating current. Therefore, circulating current elimination control is performed on each battery cluster to improve energy utilization efficiency and extend battery life. State of Charge (SOC) balancing is not considered in this stage to reduce unnecessary energy consumption and control complexity. In charging and discharging mode, operational safety of the parallel battery clusters is prioritized. Therefore, each battery cluster is first classified based on current data. Then, current direction and magnitude control are performed on the first battery cluster to ensure operational safety. SOC balancing control is performed on the second battery cluster, achieving balanced charging and discharging of the battery clusters, improving the available capacity and efficiency of the entire energy storage system, and solving the problem of battery cluster inconsistency. In addition, the hierarchical control mechanism effectively reduces redundant operations. For example, in the charging and discharging state, only the second battery cluster is subjected to SOC balancing, avoiding the problem of inconsistent current direction of battery clusters and SOC balancing at the same time, thus improving the coordination control efficiency of parallel battery clusters.

[0149] For a more detailed explanation of the working principle and procedures of this embodiment, please refer to the relevant description in Embodiment 1.

[0150] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application for those skilled in the art.

Claims

1. A hierarchical control method for a parallel battery cluster coordination controller, characterized in that, include: Real-time monitoring of the real-time operating data of parallel battery clusters, including DC bus voltage data, current data, voltage data and SOC value of each battery cluster; The system state of the parallel battery cluster is determined based on the DC bus voltage data, and the system state is either standby state or charging / discharging state. If the system is in standby mode, then circulating current elimination control is performed on each battery cluster based on the current and voltage data of each battery cluster. If the system is in a charging / discharging state, then based on the current data of each battery cluster, a number of first battery clusters that do not participate in SOC equalization control and a number of second battery clusters that participate in SOC equalization control are determined. The current direction and magnitude of each of the first battery clusters are controlled based on the current data of each battery cluster. SOC equalization control is performed on each of the second battery clusters based on the SOC value of each of the battery clusters.

2. The hierarchical control method for a parallel battery cluster coordination controller as described in claim 1, characterized in that, The circulating current elimination control for each battery cluster based on the current and voltage data of each battery cluster includes: The current is adjusted several times for each of the battery clusters until the current difference between the battery clusters is less than or equal to a first preset threshold or the system state is switched to charging and discharging state. In each current adjustment process, the current difference and voltage difference between each battery cluster are calculated based on the current and voltage data of each battery cluster, and the target battery cluster pair corresponding to the maximum current difference is determined. If the current difference of the target battery cluster pair is greater than a first preset threshold, the output voltage of the low-current battery cluster in the target battery cluster pair is increased by a first voltage value, and the output voltage of the high-current battery cluster in the target battery cluster pair is decreased by a first voltage value. The first voltage value is the product of the voltage difference of the target battery cluster pair and a preset first adjustment coefficient.

3. The hierarchical control method for a parallel battery cluster coordination controller as described in claim 1, characterized in that, The step of determining, based on the current data of each battery cluster, a number of first battery clusters that do not participate in SOC equalization control and a number of second battery clusters that participate in SOC equalization control, includes: The direction of the total current of the parallel battery clusters is determined based on the current data of each battery cluster. Traverse each of the battery clusters and determine each of the battery clusters as either the first battery cluster or the second battery cluster; During the traversal process, if the current direction of any current battery cluster is opposite to the total current direction, or if the current value of the current battery cluster is greater than a second preset threshold, then the current battery cluster is determined to be the first battery cluster; otherwise, the current battery cluster is determined to be the second battery cluster.

4. The hierarchical control method for a parallel battery cluster coordination controller as described in claim 3, characterized in that, The step of controlling the current direction and magnitude of each of the first battery clusters based on the current data of each battery cluster includes: Within a preset control time period, each of the first battery clusters is cyclically traversed, and the current direction and current magnitude of each of the first battery clusters are adjusted. During the cyclic traversal, for any current first battery cluster, the current direction and current value of the current first battery cluster are determined based on the current data of the current first battery cluster. If the current direction of the current in the current first battery cluster is opposite to the total current direction, then the output voltage of the current first battery cluster is increased or decreased by a preset second voltage value according to the total current direction. If the current value of the current first battery cluster is greater than the second preset threshold, then the current of the current first battery cluster is determined to be excessive, and the output voltage of the current first battery cluster is reduced by a third voltage value, wherein the third voltage value is the product between the current excessive value of the current first battery cluster and a preset second adjustment coefficient. If the current direction of the current in the current first battery cluster is the same as the total current direction, and the current value of the current first battery cluster is less than or equal to the second preset threshold, then the current first battery cluster is converted into the second battery cluster.

5. A hierarchical control method for a parallel battery cluster coordination controller as described in claim 3, characterized in that, The step of performing SOC balancing control on each of the second battery clusters based on the SOC value of each of the battery clusters includes: Within a preset control time period, the SOC of each second battery cluster is adjusted several times. In each SOC adjustment process, the average SOC value is calculated based on the SOC value of each battery cluster, and then the SOC difference between the SOC value of each battery cluster and the average SOC value is calculated. The output voltage of each second battery cluster is increased or decreased by a corresponding fourth voltage value, which is the product of the SOC difference of the corresponding second battery cluster and a preset third adjustment coefficient.

6. A hierarchical control method for a parallel battery cluster coordination controller as described in any one of claims 1-5, characterized in that, The hierarchical control method further includes global power consumption control for each of the battery clusters, including: Based on the voltage data of each battery cluster, determine the third battery cluster with the minimum output voltage; If the output voltage of the third battery cluster is greater than the third preset threshold, then the output voltage of each battery cluster is reduced by a fifth voltage value, which is the difference between the output voltage of the target battery cluster and the third preset threshold.

7. A hierarchical control method for a parallel battery cluster coordination controller as described in any one of claims 1-5, characterized in that, The hierarchical control method further includes global temperature control of each of the battery clusters, including: Real-time monitoring of the ambient temperature and total output current of the parallel battery cluster; The current voltage limit of the parallel battery cluster is determined based on the preset temperature / current-voltage upper limit curve. Based on the voltage data of each battery cluster, determine a number of fourth battery clusters whose output voltage is greater than the current voltage upper limit; Reduce the output voltage of each of the fourth battery clusters to the current voltage upper limit.

8. A hierarchical control system for a parallel battery cluster coordination controller, characterized in that, It includes a monitoring module, a first judgment module, a circulating current elimination module, a second judgment module, a current control module, and a SOC control module; The monitoring module is used to monitor the real-time operating data of the parallel battery clusters. The real-time operating data includes DC bus voltage data, current data, voltage data and SOC value of each battery cluster. The first judgment module is used to determine the system state of the parallel battery cluster based on the DC bus voltage data, wherein the system state is standby state or charging / discharging state; The circulating current elimination module is used to perform circulating current elimination control on each battery cluster based on the current and voltage data of each battery cluster if the system is in standby mode. The second judgment module is used to determine, based on the current data of each battery cluster, a number of first battery clusters that do not participate in SOC equalization control and a number of second battery clusters that participate in SOC equalization control if the system state is in a charging and discharging state. The current control module is used to control the current direction and current magnitude of each of the first battery clusters based on the current data of each battery cluster. The SOC control module is used to perform SOC equalization control on each of the second battery clusters based on the SOC value of each of the battery clusters.

9. A hierarchical control system for a parallel battery cluster coordination controller as described in claim 8, characterized in that, The circulating current elimination module performs circulating current elimination control on each battery cluster based on the current and voltage data of each battery cluster, including: The current is adjusted several times for each of the battery clusters until the current difference between the battery clusters is less than or equal to a first preset threshold or the system state is switched to charging and discharging state. In each current adjustment process, the current difference and voltage difference between each battery cluster are calculated based on the current and voltage data of each battery cluster, and the target battery cluster pair corresponding to the maximum current difference is determined. If the current difference of the target battery cluster pair is greater than a first preset threshold, the output voltage of the low-current battery cluster in the target battery cluster pair is increased by a first voltage value, and the output voltage of the high-current battery cluster in the target battery cluster pair is decreased by a first voltage value. The first voltage value is the product of the voltage difference of the target battery cluster pair and a preset first adjustment coefficient.

10. A hierarchical control system for a parallel battery cluster coordination controller as described in claim 8, characterized in that, The second determination module determines, based on the current data of each battery cluster, a number of first battery clusters that do not participate in SOC equalization control and a number of second battery clusters that participate in SOC equalization control, including: The direction of the total current of the parallel battery clusters is determined based on the current data of each battery cluster. Traverse each of the battery clusters and determine each of the battery clusters as either the first battery cluster or the second battery cluster; During the traversal process, if the current direction of any current battery cluster is opposite to the total current direction, or if the current value of the current battery cluster is greater than a second preset threshold, then the current battery cluster is determined to be the first battery cluster; otherwise, the current battery cluster is determined to be the second battery cluster.

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