Super capacitor group dynamic equalization control method, device, system and storage medium

Abstract

The application discloses a kind of super capacitor group dynamic equalization control method, device, system and computer readable storage medium, it is related to super capacitor energy storage control technical field.The method obtains the line resistance of each super capacitor cluster in parallel branch pre-calibrated, collects the sampling voltage of each super capacitor monomer and the branch current of each parallel branch, and determines system operating condition;According to line resistance, branch current and current direction, line voltage drop compensation is carried out on sampling voltage, to obtain the real voltage of each monomer, and determine the average real voltage of each cluster;According to operating condition and the average real voltage of each cluster, the charging current or discharging current of each cluster is distributed.The application is conducive to reducing the influence of line voltage drop on voltage sampling, and coordinating the charge-discharge state of each super capacitor cluster.

Description

Technical Field

[0001] This invention relates to the field of supercapacitor energy storage control technology, and in particular to a method, device, system and storage medium for dynamic equalization control of supercapacitor banks. Background Technology

[0002] A supercapacitor energy storage system can be composed of multiple supercapacitor clusters connected in parallel, with each cluster consisting of multiple supercapacitor cells connected in series. Due to differences in manufacturing consistency, self-discharge, equivalent series resistance, operating temperature, and aging degree among different supercapacitor cells, inconsistencies in terminal voltage and energy storage state may occur between individual supercapacitor cells and supercapacitor clusters after long-term operation. Under high-current charge and discharge conditions, these differences may have a more significant impact on system operation, with some supercapacitor clusters potentially approaching their charge or discharge limits earlier, thus affecting the system's available charge and discharge capacity and operational stability.

[0003] In existing supercapacitor equalization control methods, some allocate the charging and discharging current of each supercapacitor cluster according to a preset ratio, while others limit current based on the energy storage state of charge (SOC) or the extreme voltage values ​​of individual cells within the cluster. Preset ratios are difficult to adjust in a timely manner according to changes in the state of each supercapacitor cluster; when uniformly limiting current based on the extreme voltage values ​​of individual cells, the power output of a few poorly performing supercapacitor cells may limit the power output of their respective supercapacitor clusters and even the entire system. Furthermore, the connecting lines and related electrical components in parallel branches generate line voltage drops when high currents pass through, causing a deviation between the sampled voltage of a supercapacitor cell and its actual operating voltage. This can affect state judgment and control based on the sampled voltage. Therefore, existing equalization control methods still need further improvement in dealing with the state differences of multiple supercapacitor clusters and high-current charging and discharging conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a dynamic equalization control method, device, system, and storage medium for supercapacitor groups, in order to solve the technical problems mentioned in the background art, such as the difficulty of adapting to the state differences of each supercapacitor group, and the sampling voltage deviation caused by line voltage drop during charging and discharging, which affects the accuracy of charging and discharging current distribution.

[0005] To achieve the above objectives, according to a first aspect of the present invention, a dynamic equalization control method for supercapacitor banks is provided, applied to a supercapacitor energy storage system, wherein the supercapacitor energy storage system includes multiple supercapacitor clusters connected in parallel, each supercapacitor cluster including multiple supercapacitor cells connected in series, the method comprising:

[0006] The line resistance of each parallel branch in which each supercapacitor cluster is located is obtained in advance, and the sampling voltage of each supercapacitor cell and the branch current of each parallel branch are collected during the operation of the supercapacitor energy storage system to determine the operating conditions of the supercapacitor energy storage system.

[0007] Based on the line resistance, branch current and current direction of each parallel branch, the sampled voltage of each supercapacitor cell in the supercapacitor cluster in the parallel branch is compensated for the line voltage drop to obtain the true voltage of each supercapacitor cell, and the average true voltage of the supercapacitor cluster is determined based on the true voltage of multiple supercapacitor cells in each supercapacitor cluster.

[0008] Based on the operating conditions and the average true voltage of each supercapacitor cluster, the charging current or discharging current of each supercapacitor cluster is allocated. When the charging current is allocated differentially, the charging current allocated to the supercapacitor cluster with the higher average true voltage is less than the charging current allocated to the supercapacitor cluster with the lower average true voltage; when the discharging current is allocated differentially, the discharging current allocated to the supercapacitor cluster with the higher average true voltage is greater than the discharging current allocated to the supercapacitor cluster with the lower average true voltage.

[0009] In one possible implementation, the arithmetic mean of the true voltages of all the supercapacitor cells in each supercapacitor cluster is determined as the average true voltage of the supercapacitor cluster.

[0010] In one possible implementation, the line resistance is obtained through offline calibration and includes the power supply harness resistance, busbar resistance, terminal block resistance, and switch contactor contact resistance.

[0011] When performing the line voltage drop compensation, the line voltage drop of the parallel branch is determined based on the line resistance of each parallel branch and the branch current of the parallel branch collected in real time, and the line voltage drop is used as the voltage correction amount of the sampling voltage of each supercapacitor cell in the parallel branch.

[0012] In one possible implementation, the line voltage drop of the parallel branch is determined based on the absolute value of the branch current of each of the parallel branches and the line resistance of the parallel branch.

[0013] When the branch current of the parallel branch flows into the supercapacitor cluster in the parallel branch, the line voltage drop of the parallel branch is subtracted from the sampled voltage of each supercapacitor cell in the supercapacitor cluster to obtain the true voltage of each supercapacitor cell.

[0014] When the branch current of the parallel branch flows out of the supercapacitor cluster in the parallel branch, the line voltage drop of the parallel branch is added to the sampled voltage of each supercapacitor cell in the supercapacitor cluster to obtain the true voltage of each supercapacitor cell.

[0015] When the branch current of the parallel branch is zero, the sampled voltage of each supercapacitor cell in the supercapacitor cluster is determined as the true voltage of each supercapacitor cell.

[0016] In one possible implementation, when the operating condition is constant voltage charging condition, the difference between the maximum average true voltage and the minimum average true voltage among the multiple supercapacitor clusters is determined to obtain the inter-cluster voltage difference.

[0017] When the voltage difference between the clusters is less than or equal to a preset equalization threshold, the total charging current is equally distributed to the multiple supercapacitor clusters.

[0018] When the voltage difference between the clusters is greater than the preset equalization threshold, the total charging current is differentially allocated according to the average true voltage of each supercapacitor cluster.

[0019] In one possible implementation, when the operating condition is a high-power discharge condition, for each supercapacitor cluster, the proportion of the average true voltage of the supercapacitor cluster in the sum of the average true voltages of the multiple supercapacitor clusters is determined as the discharge current distribution parameter of the supercapacitor cluster.

[0020] The total discharge current is allocated according to the discharge current allocation parameters of each supercapacitor cluster, and the discharge current allocation parameters of each supercapacitor cluster are continuously updated according to the updated average true voltage during the discharge process.

[0021] In one possible implementation, during the operation of the supercapacitor energy storage system, the operating temperature values ​​of one or more supercapacitor clusters are also collected, and safety monitoring is performed based on the sampling voltage of each supercapacitor cell, the branch current of each parallel branch, and the operating temperature values ​​of one or more supercapacitor clusters.

[0022] When the sampling voltage of any of the supercapacitor cells is higher than or equal to the overvoltage protection threshold, or the sampling voltage of any of the supercapacitor cells is lower than or equal to the undervoltage protection threshold, or the absolute value of the branch current of any of the parallel branches is higher than or equal to the overcurrent protection threshold, or the operating temperature of any of the supercapacitor clusters is higher than or equal to the overtemperature protection threshold, the safety protection of the supercapacitor energy storage system is triggered and the charge-discharge equalization adjustment is suspended.

[0023] According to a second aspect of the present invention, a dynamic balancing control device for a supercapacitor bank is provided, applied to a supercapacitor energy storage system, the supercapacitor energy storage system comprising multiple supercapacitor clusters connected in parallel, each supercapacitor cluster comprising multiple supercapacitor cells connected in series, the device comprising an energy storage master control unit, the energy storage master control unit being used for:

[0024] The line resistance of each parallel branch containing each supercapacitor cluster, the sampling voltage of each supercapacitor cell, and the branch current of each parallel branch are obtained in advance, and the operating conditions of the supercapacitor energy storage system are determined.

[0025] Based on the line resistance, branch current and current direction of each parallel branch, the sampled voltage of each supercapacitor cell in the supercapacitor cluster in the parallel branch is compensated for the line voltage drop to obtain the true voltage of each supercapacitor cell, and the average true voltage of the supercapacitor cluster is determined based on the true voltage of multiple supercapacitor cells in each supercapacitor cluster.

[0026] Based on the operating conditions and the average true voltage of each supercapacitor cluster, a current control command is generated to control the charging current or discharging current of each supercapacitor cluster.

[0027] Specifically, when the charging current is allocated differentially, the charging current indicated by the current control command corresponding to the supercapacitor cluster with a higher average true voltage is less than the charging current indicated by the current control command corresponding to the supercapacitor cluster with a lower average true voltage; when the discharging current is allocated differentially, the discharging current indicated by the current control command corresponding to the supercapacitor cluster with a higher average true voltage is greater than the discharging current indicated by the current control command corresponding to the supercapacitor cluster with a lower average true voltage.

[0028] According to a third aspect of the present invention, a supercapacitor energy storage system is provided, comprising:

[0029] Multiple supercapacitor clusters connected in parallel, each supercapacitor cluster comprising multiple supercapacitor cells connected in series, each supercapacitor cluster being disposed in a corresponding parallel branch;

[0030] The data acquisition module is used to acquire the sampling voltage of each of the supercapacitor cells and the branch current of each of the parallel branches;

[0031] The energy storage main control unit is used to acquire the pre-calibrated line resistance of each of the parallel branches, as well as the sampling voltage and branch current acquired by the data acquisition module, and determine the operating conditions of the supercapacitor energy storage system; based on the line resistance, branch current, and current direction of each of the parallel branches, it performs line voltage drop compensation on the sampling voltage of each supercapacitor cell in the supercapacitor cluster on the parallel branch to obtain the true voltage of each supercapacitor cell, and determines the average true voltage of the supercapacitor cluster based on the true voltages of multiple supercapacitor cells in each supercapacitor cluster; based on the operating conditions and the average true voltage of each supercapacitor cluster, it generates current control commands corresponding to each supercapacitor cluster.

[0032] The drive execution module is used to control the charging current or discharging current of each supercapacitor cluster according to the current control command corresponding to each supercapacitor cluster.

[0033] Specifically, when the charging current is allocated differentially, the charging current of the supercapacitor cluster with a higher average true voltage is less than that of the supercapacitor cluster with a lower average true voltage; when the discharging current is allocated differentially, the discharging current of the supercapacitor cluster with a higher average true voltage is greater than that of the supercapacitor cluster with a lower average true voltage.

[0034] According to a fourth aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, wherein when the computer program is executed by the energy storage master control unit of a supercapacitor energy storage system, the energy storage master control unit performs the above-described supercapacitor group dynamic equalization control method.

[0035] The above-described one or more technical solutions in the embodiments of the present invention have at least one or more of the following technical effects:

[0036] This invention provides a dynamic equalization control method for supercapacitor banks. By acquiring the pre-calibrated line resistance of the parallel branches containing each supercapacitor cluster, and based on the branch current and current direction collected during operation, line voltage drop compensation is performed on the sampled voltage of each supercapacitor cell. This helps reduce the impact of line voltage drop on the voltage sampling results, making the determined true voltage of the supercapacitor cells and the average true voltage of the supercapacitor cluster closer to the corresponding actual voltage level. Furthermore, charging or discharging current is allocated according to the system operating conditions and the average true voltage of each supercapacitor cluster. Supercapacitor clusters with higher average true voltages are allocated smaller charging currents during charging and larger discharging currents during discharging. This allows for adjustment of the charging and discharging currents based on the state differences of each supercapacitor cluster, facilitating coordination of the charging and discharging states of each cluster and reducing the impact of inter-cluster state differences on the system's charging and discharging capacity and operational stability.

[0037] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0038] Figure 1 This is a flowchart illustrating a dynamic equalization control method for a supercapacitor bank according to an exemplary embodiment.

[0039] Figure 2 This is a block diagram of the control module connection of a supercapacitor energy storage system according to an exemplary embodiment.

[0040] Explanation of reference numerals in the attached diagram: 100, data acquisition module; 200, energy storage main control unit; 300, drive execution module. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0042] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of systems and methods consistent with some aspects of the invention as detailed in the appended claims.

[0043] Figure 1 This is a flowchart illustrating a dynamic equalization control method for a supercapacitor bank according to an exemplary embodiment, as shown below. Figure 1 As shown, the method is applied to a supercapacitor energy storage system, which includes multiple supercapacitor clusters connected in parallel, and each supercapacitor cluster includes multiple supercapacitor cells connected in series. The method includes:

[0044] In step S100, the line resistance of the parallel branch where each supercapacitor cluster is located is obtained in advance, and the sampling voltage of each supercapacitor cell and the branch current of each parallel branch are collected during the operation of the supercapacitor energy storage system to determine the operating conditions of the supercapacitor energy storage system.

[0045] After the supercapacitor energy storage system is powered on and started, the energy storage main control unit initializes by reading the pre-calibrated line resistance of each parallel branch, as well as the pre-set equalization threshold, overvoltage protection threshold, undervoltage protection threshold, overcurrent protection threshold, and over-temperature protection threshold. After initialization, it enters the data acquisition and charge / discharge equalization control process.

[0046] Each supercapacitor cluster is configured in a corresponding parallel branch, and the line resistance of each parallel branch is calibrated before the supercapacitor energy storage system is put into operation. The calibrated line resistances are stored in relation to their respective parallel branches and are retrieved by the energy storage main control unit during the operation of the supercapacitor energy storage system.

[0047] The data acquisition module collects the sampling voltage of each supercapacitor cell and the branch current of each parallel branch. Specifically, the data acquisition module obtains the corresponding sampling voltage through the voltage sampling channel corresponding to each supercapacitor cell and the corresponding branch current through the current sampling channel corresponding to each parallel branch, so that each sampling voltage corresponds to the corresponding supercapacitor cell and each branch current corresponds to the corresponding parallel branch.

[0048] Furthermore, the operating conditions of the supercapacitor energy storage system are determined based on its charging and discharging states, the branch currents of each parallel branch, and their current directions. These operating conditions include a static state, a constant-voltage charging state, and a high-power discharging state. When branch current flows into the corresponding supercapacitor cluster, its current direction is the charging direction; when branch current flows out of the corresponding supercapacitor cluster, its current direction is the discharging direction. The static state is defined as the supercapacitor energy storage system in a static state; the constant-voltage charging state is defined as the supercapacitor energy storage system in a constant-voltage charging state; and the high-power discharging state is defined as the supercapacitor energy storage system in a high-power discharging state.

[0049] In step S200, based on the line resistance, branch current and current direction of each parallel branch, the sampled voltage of each supercapacitor cell in the supercapacitor cluster on the parallel branch is compensated for the line voltage drop to obtain the true voltage of each supercapacitor cell, and the average true voltage of the supercapacitor cluster is determined based on the true voltage of the multiple supercapacitor cells in each supercapacitor cluster.

[0050] For each of the parallel branches, the line resistance corresponding to that parallel branch is retrieved, and the current branch current of that parallel branch is obtained. Based on the line resistance and the branch current, the line voltage drop generated by the parallel branch under the current operating state is determined, and the corresponding line voltage drop compensation method is determined based on the current direction of the branch current.

[0051] Specifically, each of the supercapacitor cells corresponds to a voltage sampling channel, and each voltage sampling channel acquires the sampling voltage of the corresponding supercapacitor cell. For supercapacitor clusters disposed on the same parallel branch, each voltage sampling channel uses the same branch reference potential of the parallel branch as the sampling reference.

[0052] The branch reference potential corresponds to the reference position closer to the power supply side in the parallel branch, and the actual reference potential on the supercapacitor cluster side corresponds to the reference position closer to the corresponding supercapacitor cluster in the parallel branch. A common line section is formed between the branch reference potential and the actual reference potential on the supercapacitor cluster side, and the common line section includes the corresponding power supply harness, busbar, terminal block, and a closed switch contactor.

[0053] When a branch current flows through the parallel branch, a line voltage drop occurs in the common line section, creating a potential difference between the branch reference potential and the actual reference potential on the supercapacitor cluster side. Since each voltage sampling channel on the same parallel branch uses the branch reference potential as its sampling reference, the potential difference is reflected in the sampling voltage of each supercapacitor cell on the parallel branch in the same direction. Therefore, for the same parallel branch, the line voltage drop determined based on the line resistance and branch current of the parallel branch is used as a common voltage correction for the sampling voltage of each supercapacitor cell on the parallel branch.

[0054] When the branch current flows into the corresponding supercapacitor cluster, the line voltage drop causes the sampled voltage of each supercapacitor cell to be higher than the corresponding real voltage, so the line voltage drop is subtracted from each sampled voltage; when the branch current flows out of the corresponding supercapacitor cluster, the line voltage drop causes the sampled voltage of each supercapacitor cell to be lower than the corresponding real voltage, so the line voltage drop is added to each sampled voltage.

[0055] The "true voltage" referred to in this embodiment is the voltage obtained after applying the line voltage drop compensation to the sampled voltage of the supercapacitor cell, used to distinguish it from the sampled voltage without the line voltage drop compensation. The true voltage does not indicate that the equivalent series resistance of the supercapacitor cell itself, sampling device errors, temperature drift, or other error factors have been eliminated.

[0056] The line voltage drop compensation is performed separately for each of the parallel branches. For any parallel branch, the line voltage drop of that branch is used as the voltage correction amount for the sampled voltage of each supercapacitor cell in the supercapacitor cluster on that branch. The sampled voltages are then corrected according to the current direction to obtain the true voltage of each supercapacitor cell. Each true voltage is associated with its corresponding supercapacitor cell to determine the average true voltage of the corresponding supercapacitor cluster.

[0057] Furthermore, for each supercapacitor cluster, the average true voltage of the supercapacitor cluster is determined based on the true voltages of the individual supercapacitors within it. This average true voltage characterizes the overall voltage level of the corresponding supercapacitor cluster under the current operating conditions and serves as the basis for subsequently allocating the charging or discharging current to each supercapacitor cluster.

[0058] During the operation of the supercapacitor energy storage system, the sampling voltage of each supercapacitor cell and the branch current of each parallel branch are updated according to a preset data acquisition cycle. Based on the updated sampling voltage, branch current, and pre-calibrated line resistance, the true voltage of each supercapacitor cell and the average true voltage of each supercapacitor cluster are re-determined. The data acquisition cycle can be set according to the control cycle of the supercapacitor energy storage system to ensure that the true voltage and the average true voltage correspond to the current operating state.

[0059] In step S300, the charging current or discharging current of each supercapacitor cluster is allocated according to the operating conditions and the average true voltage of each supercapacitor cluster. Specifically, when allocating the charging current differentially, the supercapacitor cluster with a higher average true voltage is allocated a smaller charging current than the supercapacitor cluster with a lower average true voltage; similarly, when allocating the discharging current differentially, the supercapacitor cluster with a higher average true voltage is allocated a larger discharging current than the supercapacitor cluster with a lower average true voltage. After obtaining the average true voltage of each supercapacitor cluster, the average true voltage is combined with the current operating conditions to determine the corresponding charging current or discharging current for each supercapacitor cluster within the current control cycle. The average true voltage of each supercapacitor cluster reflects the overall voltage level of the corresponding supercapacitor cluster after line voltage drop compensation, and therefore can serve as the basis for allocating charging and discharging currents among the supercapacitor clusters.

[0060] When the operating condition is constant voltage charging, the charging current is allocated according to the relative high and low average true voltages of each supercapacitor cluster. When differentiated allocation is required, a smaller charging current is allocated to the supercapacitor cluster with a higher average true voltage, and a larger charging current is allocated to the supercapacitor cluster with a lower average true voltage. This ensures that the supercapacitor clusters with lower voltage levels receive more charge and reduces the rate at which the supercapacitor clusters with higher voltage levels continue to increase.

[0061] When the operating condition is a high-power discharge condition, the discharge current is allocated according to the relative high and low average true voltages of the supercapacitor clusters. When differentiated allocation is required, a larger discharge current is allocated to the supercapacitor clusters with higher average true voltages, and a smaller discharge current is allocated to the supercapacitor clusters with lower average true voltages. This ensures that the supercapacitor clusters with higher voltage levels can handle more discharge output, and reduces the rate of further decrease in voltage for the supercapacitor clusters with lower voltage levels.

[0062] After determining the charging or discharging current of each supercapacitor cluster based on the average true voltage, the determined charging or discharging current is verified according to a pre-set charging and discharging control boundary. The charging and discharging control boundary includes an allowable charging current range and an allowable discharging current range. When the determined charging current exceeds the corresponding allowable charging current range, the charging current is adjusted according to the allowable charging current range; similarly, when the determined discharging current exceeds the corresponding allowable discharging current range, the discharging current is adjusted according to the allowable discharging current range.

[0063] Furthermore, based on the verified charging or discharging currents, current control commands corresponding to each supercapacitor cluster are generated, and these commands are provided to the corresponding drive execution modules to control each supercapacitor cluster to charge or discharge according to the allocation results. The current control command corresponding to each supercapacitor cluster corresponds to the average true voltage of that supercapacitor cluster.

[0064] During continuous charging or discharging, the sampling voltage of each supercapacitor cell and the branch current of each parallel branch are reacquired according to a preset control cycle. The charging current or discharging current of each supercapacitor cluster is redistributed according to the updated average true voltage, so that the charging and discharging current of each supercapacitor cluster can be updated as its current voltage level changes.

[0065] After completing the current distribution and outputting the current control command within the current control cycle, the system proceeds to the next control cycle without triggering safety protection. It then re-collects the sampling voltage of each supercapacitor cell, the branch current of each parallel branch, and the operating temperature of one or more supercapacitor clusters. The system also re-determines the operating conditions, line voltage drop, actual voltage, average actual voltage, and the charging or discharging current of each supercapacitor cluster. If safety protection is triggered, the charge / discharge equalization adjustment is paused.

[0066] By acquiring the pre-calibrated line resistance of the parallel branches containing each supercapacitor cluster and compensating for line voltage drop in the sampled voltage of each supercapacitor cell based on the branch current and current direction collected during operation, the influence of line voltage drop on the voltage sampling results is reduced. This makes the determined true voltage of the supercapacitor cells and the average true voltage of the supercapacitor cluster closer to the corresponding actual voltage level. Furthermore, charging or discharging currents are allocated according to the system operating conditions and the average true voltage of each supercapacitor cluster. Supercapacitor clusters with higher average true voltages are allocated smaller charging currents during charging and larger discharging currents during discharging. This allows for adjustment of the charging and discharging currents based on the state differences of each supercapacitor cluster, facilitating coordination of the charging and discharging states of each cluster and reducing the impact of inter-cluster state differences on the system's charging and discharging capacity and operational stability.

[0067] In an exemplary embodiment, the arithmetic mean of the true voltages of all the supercapacitor cells in each supercapacitor cluster is determined as the average true voltage of the supercapacitor cluster. For each supercapacitor cluster, the true voltages of all the supercapacitor cells in the cluster are obtained and processed using an arithmetic mean to obtain the average true voltage of the supercapacitor cluster. The true voltage of each supercapacitor cell is obtained by performing line voltage drop compensation on the corresponding sampled voltage, and the average true voltage is used to reflect the overall voltage level of the corresponding supercapacitor cluster after line voltage drop compensation.

[0068] Furthermore, after the supercapacitor energy storage system enters a static operating state, it is determined whether each supercapacitor cluster has reached a preset stability condition. The preset stability condition includes a current stability condition and a voltage stability condition.

[0069] Specifically, within a preset observation period, when the absolute value of the branch current of the corresponding parallel branch is continuously less than or equal to a preset resting current threshold, the current stability condition is determined to be met. The preset resting current threshold can be set according to the sampling accuracy, zero-point drift, and allowable detection error of the branch current acquisition device, and is used to identify the acquired near-zero branch current as zero current in the resting state.

[0070] During the preset observation period, the average sampled voltage of the corresponding supercapacitor cluster is continuously acquired. When the difference between the maximum and minimum values ​​of the multiple average sampled voltages acquired during the preset observation period is less than or equal to a preset voltage stability threshold, the voltage stability condition is determined to be met. The preset voltage stability threshold can be set according to the sampling accuracy, sampling resolution of the voltage sampling channel, and the allowable voltage fluctuation range under static conditions.

[0071] When both the current stabilization condition and the voltage stabilization condition are met, the corresponding supercapacitor cluster is determined to have reached the preset stabilization condition. If either condition is not met, the branch current and the average sampled voltage continue to be collected, and the preset stabilization condition is re-evaluated. The preset observation period can be set according to the sampling cycle and control cycle of the supercapacitor energy storage system, as well as the voltage stabilization time of the supercapacitor cluster after charging or discharging stops, so that the preset observation period covers multiple consecutive data acquisition cycles.

[0072] In one optional implementation, before the supercapacitor energy storage system enters the quiescent state, the average sampled voltage and energy storage SOC of the corresponding supercapacitor cluster before entering the quiescent state are stored. The average sampled voltage before entering the quiescent state can be the average sampled voltage determined during the last effective control cycle before entering the quiescent state, and the energy storage SOC is the energy storage SOC determined during that effective control cycle.

[0073] After determining that the supercapacitor cluster has reached the preset stability condition, the current branch current of the corresponding parallel branch is obtained. When the current branch current is zero, the sampled voltage of each supercapacitor cell is determined as the corresponding true voltage; when the current branch current is not zero but its absolute value is less than or equal to the preset resting current threshold, the line voltage drop is still determined based on the absolute value of the current branch current and the corresponding line resistance, and line voltage drop compensation is performed on each sampled voltage.

[0074] The energy storage SOC stored before entering the quiescent condition is corrected based on the average sampled voltage saved before entering the quiescent condition and the average true voltage determined under the quiescent stable state. The calculation formula is as follows:

[0075]

[0076] in, This indicates the State of Charge (SOC) of the energy storage stored before entering the static operating condition. This indicates the corrected SOC (State of Charge) of the energy storage system. This represents the average sampled voltage saved before entering the static state. This represents the average true voltage determined after the supercapacitor cluster reaches the preset stability condition.

[0077] The average sampling voltage is determined based on the sampling voltage of all the supercapacitor cells in the corresponding supercapacitor cluster, and the average true voltage is determined based on the true voltage of all the supercapacitor cells in the supercapacitor cluster. The original energy storage SOC is corrected based on the ratio of the average true voltage to the average sampling voltage to obtain an energy storage SOC corresponding to the average true voltage of the supercapacitor cluster in a static stable state. The corrected energy storage SOC is then used as the energy storage state parameter of the supercapacitor cluster.

[0078] In an exemplary embodiment, the line resistance is obtained through offline calibration and includes the power supply harness resistance, busbar resistance, terminal resistance, and switch contactor contact resistance. When performing line voltage drop compensation, the line voltage drop of the parallel branch is determined based on the line resistance of each parallel branch and the branch current of the parallel branch collected in real time, and the line voltage drop is used as the voltage correction amount of the sampled voltage of each supercapacitor cell in the parallel branch.

[0079] Before the supercapacitor energy storage system is put into operation, the line resistance of each of the parallel branches is calibrated offline. The line resistance of each parallel branch is used to characterize the total line resistance formed by the power supply harness, busbar, terminals, and switch contactors in that parallel branch. The length, connection structure, and contact state of the power supply harness may differ among the parallel branches; therefore, the line resistance of each parallel branch is calibrated separately and stored in correspondence with the respective parallel branch.

[0080] Furthermore, during offline calibration, the switch contactor is kept in the closed state, and the power supply harness, busbar, terminals and other electrical connection components in the parallel branch are kept in the same connection state as when the supercapacitor energy storage system is running.

[0081] Select a power supply side measurement location and a supercapacitor cluster side measurement location in the parallel branch. The power supply side measurement location is located on the side of the line section to be calibrated near the power supply device or power conversion device that provides charging current or receives discharging current for the parallel branch; the supercapacitor cluster side measurement location is located on the side of the line section to be calibrated near the corresponding supercapacitor cluster.

[0082] The section of the circuit to be calibrated between the power supply side measurement position and the supercapacitor cluster side measurement position covers the power supply harness, busbar, terminals, and closed switch contactors that need to be included in the circuit resistance, so that the power supply side measurement position and the supercapacitor cluster side measurement position are located on both sides of the conductive path formed by the above-mentioned circuit components.

[0083] During calibration, a known current is allowed to flow through the section of the circuit to be calibrated along the conductive path of the parallel branch during actual operation. After the known current stabilizes, the line voltage drop between the measurement position on the power supply side and the measurement position on the supercapacitor cluster side is measured, and the line resistance of the section of the circuit to be calibrated is determined based on the line voltage drop and the known current. The line resistance is the equivalent total resistance of the complete conductive loop traversed by the branch current flowing from the power supply side to the corresponding supercapacitor cluster and returning to the power supply side via the return path. The line voltage drop includes the voltage drop generated by the power supply path and the return path.

[0084] To reduce the impact of current fluctuations and voltage sampling errors on the calibration results, multiple line voltage drop measurements can be performed after the known current has stabilized, and the line resistance can be determined based on the results. Alternatively, measurements can be performed under multiple different known current conditions, and the line resistance can be determined based on the results. During each calibration process, the connection structure of the parallel branches and the state of the switch contactor should remain unchanged.

[0085] After calibration, the line resistances of each circuit are associated with their corresponding parallel branches and saved for later use during the operation of the supercapacitor energy storage system.

[0086] When performing the line voltage drop compensation, the line resistance corresponding to the current parallel branch is called, and the branch current of the parallel branch is acquired in real time. The specific calculation formula is as follows:

[0087]

[0088] in, This indicates the line voltage drop of the parallel branch. This represents the absolute value of the branch current in the parallel branch. This indicates the pre-calibrated line resistance of the parallel branch. The direction of the branch current is used to determine whether to subtract the line voltage drop from the sampled voltage, or to add the line voltage drop to the sampled voltage.

[0089] After determining the line voltage drop, it is used as a voltage correction amount for the sampled voltage of each supercapacitor cell in the parallel branch. This voltage correction amount corresponds to the respective parallel branch and is used to correct the impact of the line voltage drop generated when current flows through the parallel branch on the sampled voltages. Each parallel branch determines its corresponding line voltage drop using its pre-calibrated line resistance and the real-time collected branch current.

[0090] During the operation of the supercapacitor energy storage system, as the branch current is updated, the line voltage drop is re-determined based on the currently collected branch current. The line resistance is a value saved after offline calibration. Whether to correct the sampled voltage by subtracting or adding the line voltage drop is determined based on the current direction of the branch current.

[0091] In an exemplary embodiment, the line voltage drop of the parallel branch is determined based on the absolute value of the branch current of each of the parallel branches and the line resistance of the parallel branch.

[0092] When the branch current of the parallel branch flows into the supercapacitor cluster in the parallel branch, the line voltage drop of the parallel branch is subtracted from the sampled voltage of each supercapacitor cell in the supercapacitor cluster to obtain the true voltage of each supercapacitor cell.

[0093] When the branch current of the parallel branch flows out of the supercapacitor cluster in the parallel branch, the line voltage drop of the parallel branch is added to the sampled voltage of each supercapacitor cell in the supercapacitor cluster to obtain the true voltage of each supercapacitor cell.

[0094] When the branch current of the parallel branch is zero, the sampled voltage of each supercapacitor cell in the supercapacitor cluster is determined as the true voltage of each supercapacitor cell.

[0095] For each parallel branch, the branch current collected in real time is acquired, and the line voltage drop is determined based on the absolute value of the branch current and the pre-calibrated line resistance of the parallel branch. The magnitude of the line voltage drop is determined using the absolute value of the branch current, and the sampling voltage is adjusted for subtraction or addition based on the current direction of the branch current.

[0096] When the branch current flows into the corresponding supercapacitor cluster, the supercapacitor cluster is in a charging state. The line voltage drop generated when the current flows through the parallel branch causes the sampled voltage of each supercapacitor cell to be higher than the corresponding true voltage. Therefore, the true voltage of each supercapacitor cell is obtained by subtracting the line voltage drop from the sampled voltage of each supercapacitor cell in the supercapacitor cluster. The correction relationship for the true voltage is as follows:

[0097]

[0098] in, This represents the actual voltage of the supercapacitor cell. This represents the sampling voltage of the supercapacitor cell. This represents the absolute value of the branch current in the parallel branch. This indicates the pre-calibrated line resistance of the parallel branch.

[0099] When the branch current flows out of the corresponding supercapacitor cluster, the supercapacitor cluster is in a discharging state. The line voltage drop generated when the current flows through the parallel branch causes the sampled voltage of each supercapacitor cell to be lower than the corresponding true voltage. Therefore, the line voltage drop is added to the sampled voltage of each supercapacitor cell in the supercapacitor cluster to obtain the true voltage of each supercapacitor cell. The correction relationship for the true voltage is as follows:

[0100]

[0101] When the branch current is zero, the parallel branch does not experience a line voltage drop due to the branch current. Therefore, there is no need to subtract or add the sampled voltage of each supercapacitor cell in the supercapacitor cluster. The sampled voltage can be directly determined as the corresponding real voltage.

[0102] Furthermore, each of the parallel branches performs line voltage drop compensation based on its own line resistance, branch current, and current direction. Each supercapacitor cell on the same parallel branch is corrected using the line voltage drop corresponding to that parallel branch, and the corrected true voltages are stored corresponding to the respective supercapacitor cells to determine the average true voltage of the corresponding supercapacitor cluster.

[0103] In an exemplary embodiment, when the operating condition is a constant voltage charging condition, the difference between the maximum average true voltage and the minimum average true voltage among the plurality of supercapacitor clusters is determined to obtain the inter-cluster voltage difference value.

[0104] When the voltage difference between the clusters is less than or equal to a preset equalization threshold, the total charging current is equally distributed to the multiple supercapacitor clusters.

[0105] When the voltage difference between the clusters is greater than the preset equalization threshold, the total charging current is differentially allocated according to the average true voltage of each supercapacitor cluster.

[0106] When the operating condition is constant voltage charging, the average true voltage of each supercapacitor cluster within the current control cycle is acquired, and multiple average true voltages are compared to determine the maximum and minimum average true voltages. The difference between the maximum and minimum average true voltages is determined as the inter-cluster voltage difference, characterizing the degree of voltage difference between the multiple supercapacitor clusters.

[0107] The preset equalization threshold is used to form a charging current regulation dead zone. When the voltage difference between the clusters is less than or equal to the preset equalization threshold, the average true voltage difference between the multiple supercapacitor clusters is within the charging current regulation dead zone. At this time, the total charging current is equally distributed to the multiple supercapacitor clusters, so that the multiple supercapacitor clusters obtain the same charging current, reducing the need for frequent adjustments to the charging current due to small fluctuations in the average true voltage.

[0108] When the inter-cluster voltage difference exceeds the preset equalization threshold, the maximum single-cell voltage is determined from the actual voltages of all supercapacitor cells within the multiple supercapacitor clusters currently participating in charging, and a corresponding charging current allocation weight is determined based on the average actual voltage of each supercapacitor cluster. The charging current allocation weights satisfy the following relationship:

[0109]

[0110] in, Indicates the first The charging current allocation weights for each of the supercapacitor clusters. This represents the maximum true voltage of all individual supercapacitors in the multiple supercapacitor clusters participating in charging during the current control cycle. Indicates the first The average true voltage of the supercapacitor clusters. Indicates the first The average true voltage of the supercapacitor clusters. This indicates the number of supercapacitor clusters currently participating in the charging current distribution. During constant voltage charging, the maximum single-cell voltage is re-determined as the actual voltage of each supercapacitor cell is updated. .

[0111] The total charging current is allocated differentially according to the aforementioned charging current allocation weight. The charging current allocated to each of the supercapacitor clusters satisfies the following relationship:

[0112]

[0113] in, Indicates the first The charging current allocated to each of the supercapacitor clusters. This represents the total charging current.

[0114] As can be seen from the above charging current allocation method, the higher the average true voltage of the supercapacitor cluster, the smaller its corresponding charging current allocation weight, and the smaller the allocated charging current; conversely, the lower the average true voltage of the supercapacitor cluster, the larger its corresponding charging current allocation weight, and the larger the allocated charging current. Therefore, the supercapacitor cluster with the lower average true voltage receives more charging current, while the supercapacitor cluster with the higher average true voltage receives less charging current.

[0115] Furthermore, during constant voltage charging, the average true voltage of each supercapacitor cluster is continuously updated, and the inter-cluster voltage difference is re-determined based on the updated average true voltage. When the updated inter-cluster voltage difference is still greater than the preset equalization threshold, the charging current allocation weight of each supercapacitor cluster is re-determined and the allocated charging current is updated; when the updated inter-cluster voltage difference is less than or equal to the preset equalization threshold, the total charging current is equally allocated to the multiple supercapacitor clusters.

[0116] In an exemplary embodiment, when the operating condition is a high-power discharge condition, for each supercapacitor cluster, the proportion of the average true voltage of the supercapacitor cluster in the sum of the average true voltages of the plurality of supercapacitor clusters is determined as the discharge current allocation parameter of the supercapacitor cluster.

[0117] The total discharge current is allocated according to the discharge current allocation parameters of each supercapacitor cluster, and the discharge current allocation parameters of each supercapacitor cluster are continuously updated according to the updated average true voltage during the discharge process.

[0118] When the operating condition is a high-power discharge condition, the average true voltage of the multiple supercapacitor clusters currently participating in the discharge is obtained, and the multiple average true voltages are summed. For each supercapacitor cluster, the proportion of the average true voltage of the supercapacitor cluster in the sum of the average true voltages of the multiple supercapacitor clusters is determined as the discharge current allocation parameter of that supercapacitor cluster.

[0119] The discharge current distribution parameters satisfy the following relationship:

[0120]

[0121] in, Indicates the first Discharge current distribution parameters of the supercapacitor clusters Indicates the first The average true voltage of the supercapacitor clusters. Indicates the first The average true voltage of the supercapacitor clusters. This indicates the number of supercapacitor clusters currently participating in the discharge current distribution.

[0122] After determining the discharge current allocation parameters for each of the supercapacitor clusters, the total discharge current is allocated according to the discharge current allocation parameters for each cluster. The discharge current allocated to each of the supercapacitor clusters satisfies the following relationship:

[0123]

[0124] in, Indicates the first The discharge current allocated to each of the supercapacitor clusters. This represents the total discharge current.

[0125] According to the above allocation method, the supercapacitor cluster with a higher average true voltage has a larger discharge current allocation parameter and is allocated a larger discharge current; the supercapacitor cluster with a lower average true voltage has a smaller discharge current allocation parameter and is allocated a smaller discharge current. Therefore, during high-power discharge, the supercapacitor cluster with the higher average true voltage undertakes more discharge output, while the supercapacitor cluster with the lower average true voltage discharges with a smaller discharge current.

[0126] Furthermore, during the discharge process, the sampling voltage of each supercapacitor cell and the branch current of each parallel branch are continuously collected. Line voltage drop compensation is performed on the updated sampling voltage, and the average true voltage of each supercapacitor cluster is re-determined. Based on the updated average true voltage, the discharge current allocation parameters for each supercapacitor cluster are re-determined, and the total discharge current is redistributed according to the updated discharge current allocation parameters, so that the discharge current allocated to each supercapacitor cluster is updated as its average true voltage changes.

[0127] In an exemplary embodiment, during the operation of the supercapacitor energy storage system, the operating temperature values ​​of one or more supercapacitor clusters are also collected, and safety monitoring is performed based on the sampling voltage of each supercapacitor cell, the branch current of each parallel branch, and the operating temperature values ​​of one or more supercapacitor clusters.

[0128] When the sampling voltage of any of the supercapacitor cells is higher than or equal to the overvoltage protection threshold, or the sampling voltage of any of the supercapacitor cells is lower than or equal to the undervoltage protection threshold, or the absolute value of the branch current of any of the parallel branches is higher than or equal to the overcurrent protection threshold, or the operating temperature of any of the supercapacitor clusters is higher than or equal to the overtemperature protection threshold, the safety protection of the supercapacitor energy storage system is triggered and the charge-discharge equalization adjustment is suspended.

[0129] During the operation of the supercapacitor energy storage system, in addition to collecting the sampling voltage of each supercapacitor cell and the branch current of each parallel branch, the operating temperature value of one or more supercapacitor clusters is also collected. Each operating temperature value corresponds to a specific supercapacitor cluster and is used to reflect the temperature status of that supercapacitor cluster under the current operating conditions.

[0130] The operating temperature of the supercapacitor cluster can be acquired by temperature detection devices installed at the respective supercapacitor clusters and provided to the energy storage main control unit through corresponding temperature acquisition channels. The temperature detection devices can be conventional temperature sensors capable of detecting the operating temperature of the supercapacitor clusters, without limitation on their specific type, model, or installation method. The data acquisition module updates the sampling voltage, branch current, and operating temperature values ​​according to a preset data acquisition cycle, ensuring that the data used for safety monitoring corresponds to the current operating status of the supercapacitor energy storage system.

[0131] Furthermore, the energy storage control unit compares the sampled voltage of each supercapacitor cell with the overvoltage protection threshold and the undervoltage protection threshold, compares the absolute value of the branch current of each parallel branch with the overcurrent protection threshold, and compares the operating temperature value of one or more supercapacitor clusters with the overtemperature protection threshold. The branch current is determined using absolute values ​​for overcurrent detection, ensuring that both the charging current flowing into and the discharging current flowing out of the supercapacitor cluster can be safely monitored based on current magnitude.

[0132] When the sampling voltage of any of the supercapacitor cells is higher than or equal to the overvoltage protection threshold, the overvoltage protection trigger condition is determined to be met; when the sampling voltage of any of the supercapacitor cells is lower than or equal to the undervoltage protection threshold, the undervoltage protection trigger condition is determined to be met; when the absolute value of the branch current of any of the parallel branches is higher than or equal to the overcurrent protection threshold, the overcurrent protection trigger condition is determined to be met; when the operating temperature of any of the supercapacitor clusters is higher than or equal to the overtemperature protection threshold, the overtemperature protection trigger condition is determined to be met.

[0133] When any of the aforementioned protection trigger conditions is met, the energy storage master control unit triggers the safety protection of the supercapacitor energy storage system, stops generating current control commands for continuing to execute charge-discharge equalization regulation, and sends a safety control command to the drive execution module to stop executing the current current control command, thereby pausing the charge-discharge equalization regulation of each supercapacitor cluster. The execution priority of the safety protection is higher than that of the charge-discharge equalization regulation, so that the charge-discharge equalization control is subject to the joint constraints of the overvoltage protection threshold, undervoltage protection threshold, overcurrent protection threshold, and overtemperature protection threshold.

[0134] After the safety protection is triggered, the sampling voltage of each supercapacitor cell, the branch current of each parallel branch, and the operating temperature of one or more supercapacitor clusters can continue to be collected to obtain the operating status of the supercapacitor energy storage system. After the safety protection is triggered, the corresponding protection type and trigger status can be recorded, and charge-discharge equalization adjustment can be restored according to the preset protection release conditions.

[0135] In an exemplary embodiment, the present invention also provides a supercapacitor bank dynamic balancing control device applied to a supercapacitor energy storage system. The supercapacitor energy storage system includes multiple supercapacitor clusters connected in parallel, each supercapacitor cluster including multiple supercapacitor cells connected in series. The device includes an energy storage master control unit, which is used for:

[0136] The line resistance of each parallel branch containing each supercapacitor cluster, the sampling voltage of each supercapacitor cell, and the branch current of each parallel branch are obtained in advance, and the operating conditions of the supercapacitor energy storage system are determined.

[0137] Based on the line resistance, branch current and current direction of each parallel branch, the sampled voltage of each supercapacitor cell in the supercapacitor cluster in the parallel branch is compensated for the line voltage drop to obtain the true voltage of each supercapacitor cell, and the average true voltage of the supercapacitor cluster is determined based on the true voltage of multiple supercapacitor cells in each supercapacitor cluster.

[0138] Based on the operating conditions and the average true voltage of each supercapacitor cluster, a current control command is generated to control the charging current or discharging current of each supercapacitor cluster.

[0139] Specifically, when the charging current is allocated differentially, the charging current indicated by the current control command corresponding to the supercapacitor cluster with a higher average true voltage is less than the charging current indicated by the current control command corresponding to the supercapacitor cluster with a lower average true voltage; when the discharging current is allocated differentially, the discharging current indicated by the current control command corresponding to the supercapacitor cluster with a higher average true voltage is greater than the discharging current indicated by the current control command corresponding to the supercapacitor cluster with a lower average true voltage.

[0140] Specifically, the line resistance of each of the parallel branches is calibrated before the supercapacitor energy storage system is put into operation, and is stored corresponding to the respective parallel branches. During the operation of the supercapacitor energy storage system, the energy storage main control unit calls upon each of the line resistances and obtains the sampled voltage of each supercapacitor cell and the branch current of each parallel branch. Each sampled voltage corresponds to a corresponding supercapacitor cell, and each branch current and line resistance corresponds to a corresponding parallel branch.

[0141] The energy storage control unit determines the current operating condition based on the charging and discharging state of the supercapacitor energy storage system, the branch current of each parallel branch, and its current direction. The operating conditions include a static condition, a constant voltage charging condition, and a high-power discharging condition. Specifically, when branch current flows into the corresponding supercapacitor cluster, it corresponds to the charging direction; when branch current flows out of the corresponding supercapacitor cluster, it corresponds to the discharging direction.

[0142] For each of the parallel branches, the energy storage control unit determines the line voltage drop based on the line resistance and branch current of the parallel branch, and corrects the sampled voltage of each supercapacitor cell in the parallel branch according to the current direction of the branch current. When the branch current flows into the corresponding supercapacitor cluster, the line voltage drop is subtracted from each of the sampled voltages; when the branch current flows out of the corresponding supercapacitor cluster, the line voltage drop is added to each of the sampled voltages; when the branch current is zero, each of the sampled voltages is determined as the corresponding true voltage.

[0143] After obtaining the true voltage of each individual supercapacitor cell, the energy storage control unit determines the corresponding average true voltage for each supercapacitor cluster based on the true voltages of all the individual supercapacitor cells in that cluster. Each average true voltage reflects the overall voltage level of the corresponding supercapacitor cluster after line voltage drop compensation.

[0144] Furthermore, when the operating condition is constant voltage charging, the energy storage main control unit determines the inter-cluster voltage difference based on the average true voltage of the multiple supercapacitor clusters. When the inter-cluster voltage difference is less than or equal to a preset equalization threshold, a current control command is generated to equally distribute the total charging current to the multiple supercapacitor clusters; when the inter-cluster voltage difference is greater than the preset equalization threshold, a corresponding charging current allocation weight is determined based on the average true voltage of each supercapacitor cluster, and a current control command is generated to differentiate the allocation of the total charging current.

[0145] When allocating differentiated charging currents, the supercapacitor clusters with higher average true voltages are assigned smaller charging currents, while those with lower average true voltages are assigned larger charging currents. Each current control command corresponds to a specific supercapacitor cluster and indicates the charging current allocated to that cluster.

[0146] When the operating condition is a high-power discharge condition, the energy storage main control unit determines the corresponding discharge current allocation parameters based on the average true voltage of each supercapacitor cluster, and generates current control commands for allocating the total discharge current according to the discharge current allocation parameters. Supercapacitor clusters with higher average true voltages correspond to larger discharge currents, while supercapacitor clusters with lower average true voltages correspond to smaller discharge currents.

[0147] The energy storage master control unit outputs each of the current control commands to the drive execution module, which then controls the corresponding supercapacitor clusters to charge or discharge according to the current control commands. During the operation of the supercapacitor energy storage system, the energy storage master control unit re-determines the average true voltage of each supercapacitor cluster based on the updated sampled voltage and branch current, and updates the corresponding current control commands accordingly, so that the charging or discharging current of each supercapacitor cluster is adjusted according to the current voltage state.

[0148] In an exemplary embodiment, please refer to Figure 2 The present invention also provides a supercapacitor energy storage system, comprising:

[0149] Multiple supercapacitor clusters connected in parallel, each supercapacitor cluster comprising multiple supercapacitor cells connected in series, each supercapacitor cluster being disposed in a corresponding parallel branch;

[0150] The data acquisition module 100 is used to acquire the sampling voltage of each of the supercapacitor cells and the branch current of each of the parallel branches;

[0151] The energy storage main control unit 200 is used to acquire the pre-calibrated line resistance of each of the parallel branches and the sampling voltage and branch current acquired by the data acquisition module 100, and determine the operating conditions of the supercapacitor energy storage system; based on the line resistance, branch current and current direction of each of the parallel branches, it performs line voltage drop compensation on the sampling voltage of each supercapacitor cell in the supercapacitor cluster on the parallel branch to obtain the true voltage of each supercapacitor cell, and determines the average true voltage of the supercapacitor cluster based on the true voltage of multiple supercapacitor cells in each supercapacitor cluster; based on the operating conditions and the average true voltage of each supercapacitor cluster, it generates current control commands corresponding to each supercapacitor cluster.

[0152] The drive execution module 300 is used to control the charging current or discharging current of each supercapacitor cluster according to the current control command corresponding to each supercapacitor cluster.

[0153] Specifically, when the charging current is allocated differentially, the charging current of the supercapacitor cluster with a higher average true voltage is less than that of the supercapacitor cluster with a lower average true voltage; when the discharging current is allocated differentially, the discharging current of the supercapacitor cluster with a higher average true voltage is greater than that of the supercapacitor cluster with a lower average true voltage.

[0154] Specifically, multiple supercapacitor clusters are respectively disposed in corresponding parallel branches and interconnected through these parallel branches. Multiple supercapacitor cells within each supercapacitor cluster are connected in series to form the energy storage unit of that supercapacitor cluster. Each parallel branch has a pre-calibrated line resistance, which is stored corresponding to the respective parallel branch.

[0155] The data acquisition module 100 acquires the sampling voltage of each supercapacitor cell and the branch current of each parallel branch, and provides the acquisition results to the energy storage main control unit 200. Each sampling voltage corresponds to a specific supercapacitor cell, and each branch current corresponds to a specific parallel branch, enabling the energy storage main control unit 200 to process each parallel branch and the supercapacitor cluster thereon.

[0156] During safety monitoring, the data acquisition module 100 can also acquire the operating temperature values ​​of one or more supercapacitor clusters and provide the operating temperature values ​​of each supercapacitor cluster to the energy storage main control unit 200.

[0157] Furthermore, the energy storage main control unit 200 calls upon the line resistance corresponding to each of the parallel branches and determines the current operating condition based on the charging and discharging state of the supercapacitor energy storage system, the branch current, and its current direction. The operating conditions include a static condition, a constant voltage charging condition, and a high-power discharging condition. When the branch current flows into the corresponding supercapacitor cluster, it corresponds to the charging direction; when the branch current flows out of the corresponding supercapacitor cluster, it corresponds to the discharging direction.

[0158] For each of the parallel branches, the energy storage main control unit 200 determines the line voltage drop based on the line resistance and branch current of the parallel branch, and performs line voltage drop compensation on the sampled voltage of each of the supercapacitor cells in the parallel branch according to the current direction. In the charging direction, the line voltage drop is subtracted from each of the sampled voltages; in the discharging direction, the line voltage drop is added to each of the sampled voltages; when the branch current is zero, each of the sampled voltages is determined as the corresponding true voltage.

[0159] After completing the line voltage drop compensation, the energy storage main control unit 200 determines the corresponding average true voltage for each supercapacitor cluster based on the actual voltages of all the individual supercapacitors in that cluster. Each average true voltage characterizes the overall voltage level of the corresponding supercapacitor cluster after line voltage drop compensation and serves as the basis for generating the current control command.

[0160] When the operating condition is constant voltage charging, the energy storage main control unit 200 determines the charging current allocation result based on the average true voltage of each supercapacitor cluster. During differentiated allocation, a current control command indicating a smaller charging current is generated for the supercapacitor cluster with a higher average true voltage, and a current control command indicating a larger charging current is generated for the supercapacitor cluster with a lower average true voltage.

[0161] When the operating condition is a high-power discharge condition, the energy storage main control unit 200 determines the discharge current allocation result based on the average true voltage of each supercapacitor cluster. For supercapacitor clusters with higher average true voltage, a current control command indicating a larger discharge current is generated; for supercapacitor clusters with lower average true voltage, a current control command indicating a smaller discharge current is generated. Each current control command corresponds to a specific supercapacitor cluster.

[0162] The drive execution module 300 receives the current control commands generated by the energy storage master control unit 200, and adjusts the charging current or discharging current of the corresponding supercapacitor cluster according to the current value indicated by each current control command. During the operation of the supercapacitor energy storage system, the data acquisition module 100 continuously updates the sampled voltage and the branch current. The energy storage master control unit 200 re-determines the average true voltage of each supercapacitor cluster based on the updated acquisition results and updates the current control commands. The drive execution module 300 then executes the updated charging current or discharging current control.

[0163] In an exemplary embodiment, the present invention also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by the energy storage master control unit of the supercapacitor energy storage system, the energy storage master control unit performs the supercapacitor group dynamic equalization control method in the above embodiments.

[0164] Specifically, the computer program includes program instructions for executing the dynamic balancing control method for the supercapacitor bank. After reading and executing the program instructions, the energy storage main control unit obtains the pre-calibrated line resistance of the parallel branch where each of the supercapacitor clusters is located, and obtains the sampled voltage of each supercapacitor cell and the branch current of each parallel branch collected by the data acquisition module, so as to determine the operating conditions of the supercapacitor energy storage system.

[0165] When executing the program instructions, for each parallel branch, based on the line resistance, branch current and current direction of the parallel branch, the sampled voltage of each supercapacitor cell in the supercapacitor cluster in the parallel branch is compensated for the line voltage drop to obtain the true voltage of each supercapacitor cell, and the average true voltage of the supercapacitor cluster is determined based on the true voltage of the multiple supercapacitor cells in each supercapacitor cluster.

[0166] Furthermore, based on the determined operating conditions and the average true voltage of each supercapacitor cluster, a current control command corresponding to each supercapacitor cluster is generated. Under constant voltage charging conditions, the total charging current is allocated according to the average true voltage of each supercapacitor cluster; under high-power discharging conditions, the total discharging current is allocated according to the average true voltage of each supercapacitor cluster. The current control command is provided to the drive execution module, so that the drive execution module controls the charging current or discharging current of each supercapacitor cluster according to the corresponding current control command.

[0167] During the execution of the program instructions, the operating temperature values ​​of one or more supercapacitor clusters are also acquired, and safety monitoring is performed based on the sampled voltage of each supercapacitor cell, the branch current of each parallel branch, and the operating temperature values ​​of one or more supercapacitor clusters. When the overvoltage protection trigger condition, undervoltage protection trigger condition, overcurrent protection trigger condition, or overtemperature protection trigger condition is met, the safety protection of the supercapacitor energy storage system is triggered and the charge-discharge equalization adjustment is suspended.

[0168] The computer-readable storage medium may be a read-only memory, a programmable memory, flash memory, a magnetic disk, an optical disk, or other storage medium capable of storing computer programs and being read by the energy storage main control unit. The above-mentioned media forms are conventional implementations of computer program storage, and no specific type of computer-readable storage medium is limited.

[0169] The line voltage drop compensation method, average true voltage determination method, charging current distribution method, discharging current distribution method, and safety monitoring method executed by the computer program are the same as those in the above-mentioned supercapacitor group dynamic equalization control method embodiment, and will not be repeated here.

[0170] The above description describes specific embodiments of the present invention. Without departing from the inventive concept, those skilled in the art can make equivalent substitutions or modifications to the corresponding technical features based on the disclosed content of the present invention. The scope of protection of the present invention is defined by the scope of the claims.

Claims

1. A dynamic equalization control method for supercapacitor banks, applied to a supercapacitor energy storage system, wherein the supercapacitor energy storage system comprises multiple supercapacitor clusters connected in parallel, each supercapacitor cluster comprising multiple supercapacitor cells connected in series, characterized in that, The method includes: The line resistance of each parallel branch in which each supercapacitor cluster is located is obtained in advance, and the sampling voltage of each supercapacitor cell and the branch current of each parallel branch are collected during the operation of the supercapacitor energy storage system to determine the operating conditions of the supercapacitor energy storage system. Based on the line resistance, branch current and current direction of each parallel branch, the sampled voltage of each supercapacitor cell in the supercapacitor cluster in the parallel branch is compensated for the line voltage drop to obtain the true voltage of each supercapacitor cell, and the average true voltage of the supercapacitor cluster is determined based on the true voltage of multiple supercapacitor cells in each supercapacitor cluster. Based on the operating conditions and the average true voltage of each supercapacitor cluster, the charging current or discharging current of each supercapacitor cluster is allocated. When the charging current is allocated differentially, the charging current allocated to the supercapacitor cluster with the higher average true voltage is less than the charging current allocated to the supercapacitor cluster with the lower average true voltage; when the discharging current is allocated differentially, the discharging current allocated to the supercapacitor cluster with the higher average true voltage is greater than the discharging current allocated to the supercapacitor cluster with the lower average true voltage.

2. The dynamic equalization control method for supercapacitor banks according to claim 1, characterized in that, The arithmetic mean of the true voltages of all the supercapacitor cells in each supercapacitor cluster is determined as the average true voltage of the supercapacitor cluster.

3. The dynamic equalization control method for supercapacitor banks according to claim 1, characterized in that, The line resistance is obtained through offline calibration and includes the power supply harness resistance, busbar resistance, terminal block resistance, and switch contactor contact resistance. When performing the line voltage drop compensation, the line voltage drop of the parallel branch is determined based on the line resistance of each parallel branch and the branch current of the parallel branch collected in real time, and the line voltage drop is used as the voltage correction amount of the sampling voltage of each supercapacitor cell in the parallel branch.

4. The dynamic equalization control method for supercapacitor banks according to claim 1, characterized in that, The line voltage drop of each parallel branch is determined based on the absolute value of the branch current and the line resistance of that parallel branch. When the branch current of the parallel branch flows into the supercapacitor cluster in the parallel branch, the line voltage drop of the parallel branch is subtracted from the sampled voltage of each supercapacitor cell in the supercapacitor cluster to obtain the true voltage of each supercapacitor cell. When the branch current of the parallel branch flows out of the supercapacitor cluster in the parallel branch, the line voltage drop of the parallel branch is added to the sampled voltage of each supercapacitor cell in the supercapacitor cluster to obtain the true voltage of each supercapacitor cell. When the branch current of the parallel branch is zero, the sampled voltage of each supercapacitor cell in the supercapacitor cluster is determined as the true voltage of each supercapacitor cell.

5. The dynamic equalization control method for supercapacitor banks according to claim 1, characterized in that, When the operating condition is constant voltage charging condition, the difference between the maximum average true voltage and the minimum average true voltage among the multiple supercapacitor clusters is determined to obtain the inter-cluster voltage difference value. When the voltage difference between the clusters is less than or equal to a preset equalization threshold, the total charging current is equally distributed to the multiple supercapacitor clusters. When the voltage difference between the clusters is greater than the preset equalization threshold, the total charging current is differentially allocated according to the average true voltage of each supercapacitor cluster.

6. The dynamic equalization control method for supercapacitor banks according to claim 1, characterized in that, When the operating condition is a high-power discharge condition, for each supercapacitor cluster, the proportion of the average true voltage of the supercapacitor cluster in the sum of the average true voltages of multiple supercapacitor clusters is determined as the discharge current distribution parameter of the supercapacitor cluster. The total discharge current is allocated according to the discharge current allocation parameters of each supercapacitor cluster, and the discharge current allocation parameters of each supercapacitor cluster are continuously updated according to the updated average true voltage during the discharge process.

7. The dynamic equalization control method for supercapacitor banks according to claim 1, characterized in that, During the operation of the supercapacitor energy storage system, the operating temperature values ​​of one or more supercapacitor clusters are also collected, and safety monitoring is performed based on the sampling voltage of each supercapacitor cell, the branch current of each parallel branch, and the operating temperature values ​​of one or more supercapacitor clusters. When the sampling voltage of any of the supercapacitor cells is higher than or equal to the overvoltage protection threshold, or the sampling voltage of any of the supercapacitor cells is lower than or equal to the undervoltage protection threshold, or the absolute value of the branch current of any of the parallel branches is higher than or equal to the overcurrent protection threshold, or the operating temperature of any of the supercapacitor clusters is higher than or equal to the overtemperature protection threshold, the safety protection of the supercapacitor energy storage system is triggered and the charge-discharge equalization adjustment is suspended.

8. A dynamic balancing control device for supercapacitor banks, applied to a supercapacitor energy storage system, wherein the supercapacitor energy storage system comprises multiple supercapacitor clusters connected in parallel, each supercapacitor cluster comprising multiple supercapacitor cells connected in series, characterized in that, The device includes an energy storage main control unit, which is used for: The line resistance of each parallel branch containing each supercapacitor cluster, the sampling voltage of each supercapacitor cell, and the branch current of each parallel branch are obtained in advance, and the operating conditions of the supercapacitor energy storage system are determined. Based on the line resistance, branch current and current direction of each parallel branch, the sampled voltage of each supercapacitor cell in the supercapacitor cluster in the parallel branch is compensated for the line voltage drop to obtain the true voltage of each supercapacitor cell, and the average true voltage of the supercapacitor cluster is determined based on the true voltage of multiple supercapacitor cells in each supercapacitor cluster. Based on the operating conditions and the average true voltage of each supercapacitor cluster, a current control command is generated to control the charging current or discharging current of each supercapacitor cluster. Specifically, when the charging current is allocated differentially, the charging current indicated by the current control command corresponding to the supercapacitor cluster with a higher average true voltage is less than the charging current indicated by the current control command corresponding to the supercapacitor cluster with a lower average true voltage; when the discharging current is allocated differentially, the discharging current indicated by the current control command corresponding to the supercapacitor cluster with a higher average true voltage is greater than the discharging current indicated by the current control command corresponding to the supercapacitor cluster with a lower average true voltage.

9. A supercapacitor energy storage system, characterized in that, include: Multiple supercapacitor clusters connected in parallel, each supercapacitor cluster comprising multiple supercapacitor cells connected in series, each supercapacitor cluster being disposed in a corresponding parallel branch; The data acquisition module is used to acquire the sampling voltage of each of the supercapacitor cells and the branch current of each of the parallel branches; The energy storage main control unit is used to acquire the pre-calibrated line resistance of each of the parallel branches, as well as the sampling voltage and branch current acquired by the data acquisition module, and to determine the operating conditions of the supercapacitor energy storage system. Based on the line resistance, branch current and current direction of each parallel branch, the sampled voltage of each supercapacitor cell in the supercapacitor cluster in the parallel branch is compensated for the line voltage drop to obtain the true voltage of each supercapacitor cell, and the average true voltage of the supercapacitor cluster is determined based on the true voltage of multiple supercapacitor cells in each supercapacitor cluster. Based on the operating conditions and the average true voltage of each supercapacitor cluster, a current control command corresponding to each supercapacitor cluster is generated. The drive execution module is used to control the charging current or discharging current of each supercapacitor cluster according to the current control command corresponding to each supercapacitor cluster. Specifically, when the charging current is allocated differentially, the charging current of the supercapacitor cluster with a higher average true voltage is less than that of the supercapacitor cluster with a lower average true voltage; when the discharging current is allocated differentially, the discharging current of the supercapacitor cluster with a higher average true voltage is greater than that of the supercapacitor cluster with a lower average true voltage.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the energy storage master control unit of the supercapacitor energy storage system, the energy storage master control unit performs the supercapacitor group dynamic equalization control method according to any one of claims 1 to 7.

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