Power control method and apparatus for energy storage system

Abstract

The application relates to a power control method and device of an energy storage system; the method comprises the following steps: according to the obtained external DC bus voltage in a target period and real-time operation data of each super capacitor unit, the working state of each balancing circuit in the target period is determined, and according to the external DC bus voltage and the working state of each balancing circuit in the target period, the power flow direction and power size of the power converter in the target period are determined to realize the control of the power converter; by using the method, the real-time operation data of each super capacitor unit in the super capacitor module is considered, the working state of each balancing circuit is combined, the power control of the power converter is realized, the power control of the power converter can change with the change of the super capacitor unit, and the utilization rate of the stored electric energy in the super capacitor unit is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, in particular to a power control method and device of an energy storage system. BACKGROUND

[0002] At present, supercapacitors can be put into use at a faster speed than batteries, reducing the impact of power loss anomalies, so supercapacitors are often used as backup power in energy storage systems and connected to a DC bus through a corresponding converter.

[0003] However, due to slight differences caused by production and other factors, the time for each supercapacitor in the supercapacitor to be charged to the rated voltage is not the same, and overvoltage or undervoltage of the capacitor may occur, so it is usually necessary to set an equalization circuit to balance each supercapacitor. The existing supercapacitor converter control method usually only considers the changes in the overall state of the supercapacitor and the DC bus state to design the control logic, and there is a problem of low utilization rate of the electrical energy stored in the supercapacitor. SUMMARY

[0004] Therefore, it is necessary to provide a power control method and device of an energy storage system capable of improving the utilization rate of the electrical energy stored in the supercapacitor in view of the above technical problems.

[0005] In a first aspect, the present application provides a power control method of an energy storage system, applied to a control unit in the energy storage system, the energy storage system further comprising a supercapacitor module, a sampling circuit, an equalization circuit and a power converter; the supercapacitor module comprises a plurality of supercapacitor cells connected in series, each supercapacitor cell has a sampling circuit connected in parallel, the sampling circuit is used to connect an external DC bus, each two adjacent supercapacitor cells have an equalization circuit connected in parallel, and the power converter is connected between the supercapacitor module and the external DC bus; the sampling circuit, the equalization circuit and the power converter are connected with the control unit; the method comprises:

[0006] obtaining the real-time running data of each supercapacitor cell and the external DC bus voltage in a target period;

[0007] determining the working state of each equalization circuit in the target period according to the external DC bus voltage and the real-time running data;

[0008] determining the power flow direction and the power size of the power converter in the target period according to the external DC bus voltage and the working state of each equalization circuit in the target period;

[0009] controlling the power converter based on the power flow direction and the power size.

[0010] In one embodiment, determining the operating state of each balancing circuit within a target period based on the external DC bus voltage and real-time operating data includes:

[0011] determining a target power value based on a difference between a preset bus voltage and an external DC bus voltage;

[0012] According to the target power value and real-time operating data, the target operating data of each supercapacitor cell within the target period is obtained;

[0013] Based on the target operating data, the operating status of each balancing circuit within the target time period is obtained.

[0014] In one embodiment, the target operating data includes a target power value; and obtaining the operating status of each balancing circuit within a target time period based on the target operating data includes:

[0015] Determine the integral corresponding to each supercapacitor cell within the target period according to the target power value, and the integral corresponding to the supercapacitor cell is used to characterize the operating status of each supercapacitor;

[0016] If the integral corresponding to the supercapacitor cell is not within the preset range, the balancing circuit corresponding to the supercapacitor cell is enabled during the target period;

[0017] If the integral corresponding to the supercapacitor cell is within a preset range, the balancing circuit corresponding to the supercapacitor cell is in a disabled state during the target period.

[0018] In one embodiment, determining the power flow direction and power level of the power converter within the target time period based on the external DC bus voltage and the operating status of each balancing circuit within the target time period includes:

[0019] determining a target power value based on a difference between a preset bus voltage and an external DC bus voltage;

[0020] The power level of the power converter within the target time period is determined based on the target power value, the external DC bus voltage, and the operating status of each balancing circuit within the target time period.

[0021] In one embodiment, determining the power of the power converter within the target period based on the target power value, the external DC bus voltage, and the operating state of each balancing circuit within the target period includes:

[0022] When the variance of the external DC bus voltage in the target period is greater than the preset variance and all balancing circuits in the target period are in a disabled state, the target power value is determined as the power of the power converter in the target period.

[0023] In one embodiment, determining the power of the power converter within the target period based on the target power value, the external DC bus voltage, and the operating state of each balancing circuit within the target period includes:

[0024] If any balancing circuit is in an enabled state during the target period, and the variance of the external DC bus voltage during the target period is less than or equal to the preset variance, the power of the power converter during the target period is determined by multiplying the proportional value by the target power value, where the proportional value is determined by the variance of the external DC bus voltage during the target period.

[0025] If the balancing circuits are all in an enabled state during the target period, the power size of the power converter during the target period is determined according to the target operation data.

[0026] In one embodiment, obtaining the external DC bus voltage within a target time period includes:

[0027] Constructing a prediction model for predicting the external DC bus voltage;

[0028] The voltage data in the historical period is input into the prediction model to obtain the external DC bus voltage in the target period, wherein the historical period is a period before the target period.

[0029] In a second aspect, the present application further provides a control unit, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0030] In a third aspect, the present application also provides an energy storage system, which further includes a supercapacitor module, a sampling circuit, a balancing circuit, and a power converter; the supercapacitor module includes a plurality of supercapacitor cells connected in series, each supercapacitor cell is connected in parallel with a sampling circuit, the sampling circuit is used to connect to an external DC bus, and a balancing circuit is connected in parallel between every two adjacent supercapacitor cells, and the power converter is connected between the supercapacitor module and the external DC bus; the sampling circuit, the balancing circuit, and the power converter are all connected to the control unit;

[0031] The control unit is used to execute the steps of the above method.

[0032] In a fourth aspect, the present application also provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0033] The power control method and device of the above-mentioned energy storage system determine the working state of each balancing circuit within the target period based on the external DC bus voltage and the real-time operating data of each supercapacitor cell within the target period, and determine the power flow direction and power size of the power converter within the target period based on the external DC bus voltage and the working state of each balancing circuit within the target period, thereby realizing control of the power converter; the present application realizes power control of the power converter by considering the real-time operating data of each supercapacitor cell in the supercapacitor module and combining the working state of each balancing circuit, so that it can change with the change of the supercapacitor cell, thereby improving the utilization rate of the electric energy stored in the supercapacitor cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 Schematic diagram of the structure of an energy storage system in one embodiment;

[0036] Figure 2 1 is a flow chart of a power control method for an energy storage system according to an embodiment;

[0037] Figure 3 is a structural block diagram of a power control device of an energy storage system in one embodiment;

[0038] Figure 4 1 is a diagram of the internal structure of a control unit in one embodiment. DETAILED DESCRIPTION

[0039] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0041] When used herein, the singular forms "a", "an", and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

[0042] Supercapacitors are a new type of energy storage device that combines the characteristics of both secondary batteries and electrostatic capacitors. They offer outstanding advantages such as safety and reliability, high power density, fast charging, high discharge power, long service life, maintenance-free operation, a wide operating temperature range, and clean and environmentally friendly properties. They are particularly suitable for long-life power supplies and are widely used in fields such as distributed power generation and public transportation. Compared to batteries, supercapacitors can be put into operation more quickly and reduce the impact of power failures. Therefore, they are widely used as backup power sources, connected to corresponding power converters and connected to the DC bus.

[0043] However, due to slight variations caused by factors such as production, the time it takes for each supercapacitor cell to charge to rated voltage varies, making it prone to capacitor overvoltage or undervoltage. This often requires a balancing circuit to balance the individual supercapacitors. Existing supercapacitor converter control typically only considers the overall state of the supercapacitor and the changes in the DC bus state to design the control logic. The converter's charge and discharge power control process still needs to be improved, and the utilization rate of the energy stored in the supercapacitor cells remains low.

[0044] The power control method of the energy storage system provided in the embodiment of the present application can be applied to Figure 1 The energy storage system shown in FIG. The energy storage system includes a supercapacitor module 11, a sampling circuit 12, a balancing circuit 13, a power converter 14, and a control unit 15. The supercapacitor module 11 includes multiple supercapacitor cells connected in series. Each supercapacitor cell is connected in parallel with a sampling circuit 12. The energy storage system is further provided with a sampling circuit 12 connected to an external DC bus. A balancing circuit 12 is connected in parallel between every two adjacent supercapacitor cells. The power converter 14 is connected between the supercapacitor module 11 and the external DC bus. The sampling circuit 12, the balancing circuit 13, and the power converter 14 are all connected to the control unit 15.

[0045] Exemplarily, the power converter may be a DC / DC converter.

[0046] In an exemplary embodiment, Figure 2 As shown, a power control method for an energy storage system is provided, which is applied to Figure 1Taking the energy storage system in [1] as an example, the method includes:

[0047] S202 : Acquire real-time operating data of the external DC bus voltage and each supercapacitor cell within a target time period.

[0048] Among them, the target period can be set according to actual conditions. For example, if the supercapacitor module is currently charging, the target period can be the period from the current moment to the end of charging; correspondingly, if the supercapacitor module is currently discharging, the target period can be the period from the current moment to the end of discharging.

[0049] Specifically, the control unit can obtain the external DC bus voltage and the real-time operating data of each supercapacitor cell within the target time period collected by the sampling circuit.

[0050] Exemplarily, the real-time operating data of the supercapacitor cells may include the voltage, current, power, and remaining power of each supercapacitor cell, etc., which is not limited in the embodiments of the present application.

[0051] In one embodiment, obtaining the external DC bus voltage within a target time period includes:

[0052] Constructing a prediction model for predicting the external DC bus voltage;

[0053] The voltage data in the historical period is input into the prediction model to obtain the external DC bus voltage in the target period, wherein the historical period is a period before the target period.

[0054] The voltage data may include historical operating data of the external DC bus (including the external DC bus voltage); and the prediction model may be a long short-term memory network model.

[0055] Specifically, the control unit can train a long short-term memory network model based on the historical operating data of the external DC bus, and input the external DC bus voltage in the historical period into the trained long short-term memory network model to obtain the external DC bus voltage in the target period.

[0056] For example, if the target period is a charging period, the historical period may be one or more charging periods before the current period; if the target period is a discharging period, the historical period may be one or more discharging periods before the current period.

[0057] S204: Determine the operating state of each balancing circuit within the target time period according to the external DC bus voltage and the real-time operating data.

[0058] Specifically, the control unit can determine the target operating data of each supercapacitor cell within the target period based on the real-time operating data of each supercapacitor cell and the external DC bus voltage; and determine the working state of the balancing circuit corresponding to each supercapacitor cell within the target period based on the target operating data.

[0059] In one embodiment, determining the operating state of each balancing circuit within a target period based on the external DC bus voltage and real-time operating data includes:

[0060] determining a target power value based on a difference between a preset bus voltage and an external DC bus voltage;

[0061] According to the target power value and real-time operating data, the target operating data of each supercapacitor cell within the target period is obtained;

[0062] Based on the target operating data, the operating status of each balancing circuit within the target time period is obtained.

[0063] The preset bus voltage may be set according to actual conditions and may be a standard bus voltage.

[0064] Specifically, the voltage of the DC bus can reflect the power generation situation of the (new energy) power grid. For example, when there is sufficient sunlight and the temperature is high, the DC bus voltage (external DC bus voltage) will usually be higher than the standard bus voltage. At this time, the supercapacitor cells used as energy storage usually need to consume some of the electricity. Conversely, the DC bus voltage will be lower than the standard bus voltage. At this time, the supercapacitor cells used as energy storage usually need to supplement some of the electricity to the DC bus. Therefore, the power that the supercapacitor module needs to release or absorb when the DC bus is adjusted from the current voltage to the standard bus voltage can be measured in advance. After measuring the voltage difference on the DC bus, the target power value can be determined. Based on the real-time operating data of the current supercapacitor cell, after simulating the operation according to the target power value, the target operating data of each supercapacitor cell in the target time period can be calculated, and based on the target operating data, the working status of each balancing circuit in the target time period can be obtained.

[0065] It should be noted that the power flow direction of the power converter connected to the supercapacitor module can be determined by pre-measuring whether the DC bus voltage is adjusted from the current voltage to the standard bus voltage to determine whether the supercapacitor module needs to release or absorb power.

[0066] In an embodiment of the present application, the target power value is determined based on the difference between the preset bus voltage and the external DC bus voltage, and the target operating data of each supercapacitor cell in the target time period is obtained based on the target power value and real-time operating data. Finally, the working status of each balancing circuit in the target time period is obtained, which facilitates subsequent power control of the power converter and improves the utilization rate of the electric energy stored in the supercapacitor cell.

[0067] In one embodiment, the target operating data includes a target power value; and obtaining the operating status of each balancing circuit within a target time period based on the target operating data includes:

[0068] Determine the integral corresponding to each supercapacitor cell within the target period according to the target power value, and the integral corresponding to the supercapacitor cell is used to characterize the operating status of each supercapacitor;

[0069] If the integral corresponding to the supercapacitor cell is not within the preset range, the balancing circuit corresponding to the supercapacitor cell is enabled during the target period;

[0070] If the integral corresponding to the supercapacitor cell is within a preset range, the balancing circuit corresponding to the supercapacitor cell is in a disabled state during the target period.

[0071] Among them, the preset interval can be set according to actual conditions and is not limited in the embodiments of this application.

[0072] Specifically, if the integral corresponding to the supercapacitor cell is not in the preset interval, it can be indicated that each supercapacitor cell is at risk of overcharging or over-discharging, and at this time the working state of the balancing circuit corresponding to each supercapacitor cell is enabled; if the integral corresponding to the supercapacitor cell is in the preset interval, it can be indicated that each supercapacitor cell is not at risk of overcharging or over-discharging, and at this time the working state of the balancing circuit corresponding to each supercapacitor cell is disabled.

[0073] It should be noted that the integral corresponding to each supercapacitor cell in the target time period can be obtained by obtaining a power curve corresponding to each supercapacitor cell and integrating time based on the power curve.

[0074] S206 , determining the power flow direction and power level of the power converter within the target period according to the external DC bus voltage and the working status of each balancing circuit within the target period.

[0075] Specifically, the control unit may determine the power flow direction and power level of the power converter within the target period according to the external DC bus voltage and the working status of each balancing circuit within the target period.

[0076] In one embodiment, determining the power flow direction and power level of the power converter within the target time period based on the external DC bus voltage and the operating status of each balancing circuit within the target time period includes:

[0077] determining a target power value based on a difference between a preset bus voltage and an external DC bus voltage;

[0078] The power level of the power converter within the target time period is determined based on the target power value, the external DC bus voltage, and the operating status of each balancing circuit within the target time period.

[0079] Specifically, the control unit can first determine the initial target power value based on the difference between the preset bus voltage and the external DC bus voltage, and then determine the power size of the power converter within the target time period based on the target power value, the external DC bus voltage and the working status of each balancing circuit within the target time period.

[0080] In an embodiment of the present application, the power size of the power converter within the target time period is determined based on the acquired target power value, the external DC bus voltage, and the working status of each balancing circuit within the target time period, so as to subsequently perform power control of the power converter so that it can change with the changes in the supercapacitor cell, thereby improving the utilization rate of the electric energy stored in the supercapacitor cell.

[0081] In one embodiment, determining the power of the power converter within the target period based on the target power value, the external DC bus voltage, and the operating state of each balancing circuit within the target period includes:

[0082] When the variance of the external DC bus voltage in the target period is greater than the preset variance and all balancing circuits in the target period are in a disabled state, the target power value is determined as the power of the power converter in the target period.

[0083] Among them, the method of obtaining the variance of the external DC bus voltage is an existing method and is not limited in the embodiment of the present application; the preset variance can be set according to actual conditions and is not limited in the embodiment of the present application.

[0084] Specifically, the variance of the external DC bus voltage during the target period is greater than the preset variance, and all balancing circuits are in a disabled state during the target period. This can be indicated that the new energy power generation system connected to the external DC bus has large fluctuations and needs to be supplemented or absorbed. At this time, there is no risk of overcharging or over-discharging the supercapacitor module. Therefore, the target power value can be used as the power size of the power converter during the target period.

[0085] In an embodiment of the present application, by considering the state of the external DC bus and combining the operating state of the supercapacitor cell (the operating state of the balancing circuit), the power size of the power converter within the target time period is determined so that it can change with the changes in the supercapacitor cell, thereby improving the utilization rate of the electrical energy stored in the supercapacitor cell.

[0086] In one embodiment, determining the power of the power converter within the target period based on the target power value, the external DC bus voltage, and the operating state of each balancing circuit within the target period includes:

[0087] If any balancing circuit is in an enabled state during the target period, and the variance of the external DC bus voltage during the target period is less than or equal to the preset variance, the power of the power converter during the target period is determined by multiplying the proportional value by the target power value, where the proportional value is determined by the variance of the external DC bus voltage during the target period.

[0088] If the balancing circuits are all in an enabled state during the target period, the power size of the power converter during the target period is determined according to the target operation data.

[0089] The ratio value can be set according to actual conditions. In the embodiment of the present application, the ratio value is less than 1.

[0090] Specifically, when the balancing circuit is in the enabled state, it can be indicated that there is a risk of overcharging or over-discharging of the supercapacitor module. At this time, the charging power or discharging power of the power converter is reduced according to a proportional value. The proportional value k can be obtained by the following formula:

[0091] ;

[0092] in, Expressed as the variance of the external DC bus voltage; Expressed as the preset variance.

[0093] For example, when the working state of the balancing circuit is enabled during the target time period and the variance of the external DC bus voltage during the target time period is greater than the preset variance, the difference between the external DC bus voltage and the standard bus voltage at each moment during the target time period can be calculated. If the difference is greater than the preset difference, the operation is performed according to the target power value. If the difference is not greater than the preset difference, the operation is performed according to the product of the target power value and the proportional value. The preset difference can be set according to actual conditions and is not limited in the embodiment of the present application.

[0094] When the working states of all balancing circuits are enabled within the target time period, it indicates that overcharging or over-discharging is about to occur. At this time, the demand of the external DC bus is no longer considered, and the power size of the power converter within the target time period is determined directly according to the remaining charge capacity or remaining discharge capacity of each supercapacitor cell and the current operating voltage. Specifically, each supercapacitor cell can stop output after reaching the maximum or minimum cut-off voltage, and the integral value of the power size of the power converter within the target time period is not greater than the sum of the remaining charge capacity or the sum of the remaining discharge capacity of each supercapacitor cell.

[0095] In an embodiment of the present application, by considering the state of the external DC bus and combining the operating state of the supercapacitor cell (the operating state of the balancing circuit), the power size of the power converter within the target time period is determined so that it can change with the changes in the supercapacitor cell, thereby improving the utilization rate of the electrical energy stored in the supercapacitor cell.

[0096] S208 , controlling the power converter based on the power flow direction and power magnitude.

[0097] Specifically, after obtaining the power flow direction and power size, the control unit can modulate the corresponding duty cycle signal through a conventional logic circuit and send it to the gate of each switch tube in the power converter, thereby controlling the power converter.

[0098] It should be noted that the power flow direction can be determined by the external DC bus voltage.

[0099] In the power control method of the above-mentioned energy storage system, the operating state of each balancing circuit within the target period is determined based on the external DC bus voltage and the real-time operating data of each supercapacitor cell within the target period. The power flow direction and power level of the power converter within the target period are determined based on the external DC bus voltage and the operating state of each balancing circuit within the target period. The power converter is controlled so that it can change with the changes in the supercapacitor cell, thereby improving the utilization rate of the electric energy stored in the supercapacitor cell.

[0100] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0101] Based on the same inventive concept, embodiments of the present application also provide a power control device for an energy storage system for implementing the aforementioned power control method for an energy storage system. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more embodiments of the power control device for an energy storage system provided below can be found in the aforementioned limitations of the power control method for an energy storage system, and will not be further elaborated here.

[0102] In an exemplary embodiment, Figure 3 As shown, a power control device 300 for an energy storage system is provided, which is applied to a control unit in the energy storage system. The energy storage system also includes a supercapacitor module, a sampling circuit, a balancing circuit, and a power converter. The supercapacitor module includes a plurality of supercapacitor cells connected in series, each of which is connected in parallel with a sampling circuit. The sampling circuit is used to connect to an external DC bus. A balancing circuit is connected in parallel between every two adjacent supercapacitor cells. The power converter is connected between the supercapacitor module and the external DC bus. The sampling circuit, the balancing circuit, and the power converter are all connected to the control unit. The device 300 includes:

[0103] An acquisition module 301 is configured to acquire the external DC bus voltage and real-time operating data of each supercapacitor cell within a target period;

[0104] A state determination module 302 is configured to determine the operating state of each balancing circuit within a target period based on the external DC bus voltage and real-time operating data;

[0105] The power determination module 303 is used to determine the power flow direction and power level of the power converter within the target period according to the external DC bus voltage and the working status of each balancing circuit within the target period;

[0106] The control module 304 is configured to control the power converter based on the power flow direction and power level.

[0107] In one embodiment, the state determination module 302 is further configured to determine a target power value based on a difference between a preset bus voltage and an external DC bus voltage;

[0108] According to the target power value and real-time operating data, the target operating data of each supercapacitor cell within the target period is obtained;

[0109] Based on the target operating data, the operating status of each balancing circuit within the target time period is obtained.

[0110] In one embodiment, the target operating data includes a target power value; the state determination module 302 is further configured to determine an integral corresponding to each supercapacitor cell within a target period based on the target power value, wherein the integral corresponding to the supercapacitor cell is used to represent the operating state of each supercapacitor;

[0111] If the integral corresponding to the supercapacitor cell is not within the preset range, the balancing circuit corresponding to the supercapacitor cell is enabled during the target period;

[0112] If the integral corresponding to the supercapacitor cell is within a preset range, the balancing circuit corresponding to the supercapacitor cell is in a disabled state during the target period.

[0113] In one embodiment, the power determination module 303 is further configured to determine a target power value based on a difference between a preset bus voltage and an external DC bus voltage;

[0114] The power level of the power converter within the target time period is determined based on the target power value, the external DC bus voltage, and the operating status of each balancing circuit within the target time period.

[0115] In one embodiment, the power determination module 303 is further used to determine the target power value as the power size of the power converter within the target time period when the variance of the external DC bus voltage within the target time period is greater than the preset variance and all balancing circuits within the target time period are in a disabled state.

[0116] In one embodiment, the power determination module 303 is further configured to, if any balancing circuit is in an enabled state during the target period and the variance of the external DC bus voltage during the target period is less than or equal to a preset variance, use the product of the proportional value and the target power value as the power of the power converter during the target period, where the proportional value is determined by the variance of the external DC bus voltage during the target period;

[0117] If the balancing circuits are all in an enabled state during the target period, the power size of the power converter during the target period is determined according to the target operation data.

[0118] In one embodiment, the acquisition module 301 is further configured to construct a prediction model for predicting the external DC bus voltage;

[0119] The voltage data in the historical period is input into the prediction model to obtain the external DC bus voltage in the target period, wherein the historical period is a period before the target period.

[0120] Each module in the power control device of the energy storage system described above can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0121] In an exemplary embodiment, a control unit is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0122] Specifically, if Figure 4 As shown, the control unit 4 may include a processor 40, a memory 41, and a computer program 42 stored in the memory 41 and executable on the processor 40. When the processor 40 executes the computer program 42, the steps in the embodiment of the power control method for the energy storage system described above are implemented, for example Figure 2 Alternatively, the processor 40 may implement the functions of each module / unit in the above-mentioned system embodiments when executing the computer program 42, for example Figure 3 The functions of each module are shown.

[0123] Exemplarily, the computer program 42 may be divided into one or more modules / units, one or more of which are stored in the memory 41 and executed by the processor 40 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program 42 in the control unit 4.

[0124] The control unit 4 may be a terminal or a server, and may include, but not limited to, a processor 40 and a memory 41. Those skilled in the art will appreciate that Figure 4 This is only an example of the control unit 4 and does not constitute a limitation on the control unit 4. The control unit 4 may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal may also include input and output devices, network access devices, buses, etc.

[0125] The processor 40 may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0126] The memory 41 can be an internal storage unit of the control unit 4, such as the hard drive or memory of the control unit 4. The memory 41 can also be an external storage device of the control unit 4, such as a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. equipped on the control unit 4. Furthermore, the memory 41 can include both the internal storage unit of the control unit 4 and an external storage device. The memory 41 is used to store computer programs and other programs and data required by the terminal. The memory 41 can also be used to temporarily store data that has been output or is about to be output.

[0127] Exemplarily, the control unit may be a server, and the control unit (computer device) includes a processor, memory, an input / output (I / O) interface, and a communication interface. The processor, memory, and I / O interface are connected via a system bus, and the communication interface is connected to the system bus via the I / O interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the computer device is used to store external DC bus voltage and real-time operating data. The I / O interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals via a network connection. When executed by the processor, the computer program implements a power control method for an energy storage system.

[0128] The control unit can also be a terminal. The control unit (computer device) includes a processor, memory, an input / output interface, a communication interface, a display unit, and an input device. The processor, memory, and input / output interface are connected via a system bus, while the communication interface, display unit, and input device are connected to the system bus via the input / output interface. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and computer program stored in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals via wired or wireless communication. The wireless communication can be achieved via Wi-Fi, a mobile cellular network, near-field communication (NFC), or other technologies. When executed by the processor, the computer program implements a power control method for an energy storage system.

[0129] In an exemplary embodiment, an energy storage system is provided, which further includes a supercapacitor module, a sampling circuit, a balancing circuit, and a power converter; the supercapacitor module includes a plurality of supercapacitor cells connected in series, each supercapacitor cell is connected in parallel with a sampling circuit, the sampling circuit is used to connect to an external DC bus, a balancing circuit is connected in parallel between every two adjacent supercapacitor cells, and a power converter is connected between the supercapacitor module and the external DC bus; the sampling circuit, the balancing circuit, and the power converter are all connected to a control unit;

[0130] The control unit is used to execute the steps of the above method.

[0131] Specifically, if Figure 1 As shown, the energy storage system includes a supercapacitor module 11, a sampling circuit 12, a balancing circuit 13, a power converter 14 and a control unit 15; the supercapacitor module 11 includes a plurality of supercapacitor cells connected in series; each supercapacitor cell is connected in parallel with a sampling circuit 12; the energy storage system is also provided with a sampling circuit 12 connected to an external DC bus; a balancing circuit 12 is connected in parallel between every two adjacent supercapacitor cells; the power converter 14 is connected between the supercapacitor module 11 and the external DC bus; the sampling circuit 12, the balancing circuit 13 and the power converter 14 are all connected to the control unit 15.

[0132] Exemplarily, the power converter may be a DC / DC converter.

[0133] It should be noted that sampling circuit 12 can be used to collect real-time operating data from each supercapacitor cell and DC bus operating data and transmit it to control unit 15. The control unit can be an MCU (Microcontroller Unit), a single-chip microcomputer, etc., without limitation. Balancing circuit 13 can be used to balance the two connected supercapacitor cells based on their operating status to prevent overcharging or over-discharging of the supercapacitor cells during the charging and discharging process.

[0134] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the power control method of the energy storage system is implemented.

[0135] For example, Figure 4 As shown, a computer-readable storage medium may store a computer program 42. The computer program 42 includes program instructions. When executed by the processor 40, the program instructions implement all or part of the process steps in the above-described method embodiments. The computer program 42 may also instruct related hardware to complete the process. The computer program 42 may be stored in a computer-readable storage medium. When executed by the processor 40, the computer program 42 may implement the steps of each of the above-described method embodiments. The computer program 42 includes computer program code, which may be in source code form, object code form, executable file, or some intermediate form. Computer-readable media may include any entity or device capable of carrying computer program code, a recording medium, a USB flash drive, a mobile hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, an electrical signal, and a software distribution medium.

[0136] The computer-readable storage medium can be the internal storage unit of the terminal in any of the aforementioned embodiments, such as the terminal's hard drive or memory. The computer-readable storage medium can also be an external storage device of the terminal, such as a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. Furthermore, the computer-readable storage medium can include both the terminal's internal storage unit and an external storage device. The computer-readable storage medium is used to store computer programs and other programs and data required by the terminal. The computer-readable storage medium can also be used to temporarily store data that has been output or is about to be output.

[0137] It should be noted that the data involved in this application (including but not limited to data used for analysis, stored data, displayed data, etc.) are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0138] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), quantum computing-based data processing logic devices, artificial intelligence (AI) processors, and the like.

[0139] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0140] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A power control method for an energy storage system, characterized in that: A control unit applied to the energy storage system, the energy storage system further comprising a supercapacitor module, a sampling circuit, a balancing circuit, and a power converter; the supercapacitor module comprises a plurality of supercapacitor cells connected in series, each of which is connected in parallel with the sampling circuit; the energy storage system is further provided with the sampling circuit connected to an external DC bus, the balancing circuit is connected in parallel between every two adjacent supercapacitor cells, and the power converter is connected between the supercapacitor module and the external DC bus; the sampling circuit, the balancing circuit, and the power converter are all connected to the control unit; the method comprises: Acquiring real-time operating data of the external DC bus voltage and each supercapacitor cell within a target period; determining, according to the external DC bus voltage and the real-time operating data, an operating state of each of the balancing circuits within the target time period; Determining the power flow direction and power level of the power converter within the target time period based on the external DC bus voltage and the operating status of each of the balancing circuits within the target time period; The power converter is controlled based on the power flow direction and the power magnitude.

2. The method according to claim 1, characterized in that The determining, according to the external DC bus voltage and the real-time operating data, the operating state of each balancing circuit within the target time period includes: determining a target power value based on a difference between a preset bus voltage and the external DC bus voltage; Obtaining target operating data of each supercapacitor cell within the target time period according to the target power value and the real-time operating data; Based on the target operating data, the operating status of each of the balancing circuits within the target time period is obtained.

3. The method according to claim 2, characterized in that The target operation data includes the target power value; and obtaining the operating state of each of the balancing circuits within the target time period based on the target operation data includes: Determining the integral corresponding to each supercapacitor cell within the target time period according to the target power value, where the integral corresponding to the supercapacitor cell is used to characterize the operating state of each supercapacitor; wherein determining the integral corresponding to each supercapacitor cell within the target time period according to the target power value includes: obtaining a power curve corresponding to the supercapacitor cell, integrating time based on the power curve, and obtaining the integral corresponding to each supercapacitor cell within the target time period; If the integral corresponding to the supercapacitor cell is not within the preset range, the balancing circuit corresponding to the supercapacitor cell is in an enabled state during the target period; If the integral corresponding to the supercapacitor cell is within the preset interval, the balancing circuit corresponding to the supercapacitor cell is in a disabled state during the target period.

4. The method according to claim 2, characterized in that The determining, based on the external DC bus voltage and the operating states of the balancing circuits within the target time period, the power flow direction and power magnitude of the power converter within the target time period includes: determining a target power value based on a difference between a preset bus voltage and the external DC bus voltage; The power level of the power converter within the target time period is determined based on the target power value, the external DC bus voltage, and the operating status of each of the balancing circuits within the target time period.

5. The method according to claim 4, characterized in that The determining the power of the power converter within the target time period based on the target power value, the external DC bus voltage, and the operating state of each balancing circuit within the target time period includes: When the variance of the external DC bus voltage in the target period is greater than a preset variance and all the balancing circuits are in a disabled state in the target period, the target power value is determined as the power size of the power converter in the target period.

6. The method according to claim 4, characterized in that The determining the power of the power converter within the target time period based on the target power value, the external DC bus voltage, and the operating state of each balancing circuit within the target time period includes: If any of the balancing circuits is in an enabled state during the target period, and the variance of the external DC bus voltage during the target period is less than or equal to a preset variance, then multiplying a proportional value by the target power value as the power magnitude of the power converter during the target period, the proportional value being determined by the variance of the external DC bus voltage during the target period; If the balancing circuits are all in an enabled state within the target time period, the power level of the power converter within the target time period is determined according to the target operation data.

7. The method according to claim 1, characterized in that The obtaining of the external DC bus voltage within the target time period includes: Constructing a prediction model for predicting the external DC bus voltage; The voltage data in a historical period is input into the prediction model to obtain the external DC bus voltage in the target period, wherein the historical period is a period before the target period.

8. A control unit comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

9. An energy storage system, characterized in that: The energy storage system further includes a supercapacitor module, a sampling circuit, a balancing circuit, and a power converter; the supercapacitor module includes a plurality of supercapacitor cells connected in series, each of which is connected in parallel with the sampling circuit; the energy storage system is further provided with the sampling circuit connected to an external DC bus, the balancing circuit is connected in parallel between every two adjacent supercapacitor cells, and the power converter is connected between the supercapacitor module and the external DC bus; the sampling circuit, the balancing circuit, and the power converter are all connected to the control unit; The control unit is configured to execute the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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