Power control method and apparatus for energy storage system

Abstract

The present application relates to a power control method and apparatus for an energy storage system. The method comprises: on the basis of an acquired external direct-current bus voltage within a target time period and real-time operation data of each supercapacitor cell, determining the working state of each balancing circuit within the target time period; and on the basis of the external direct-current bus voltage and the working state of each balancing circuit within the target time period, determining the power flow direction and power magnitude of a power converter within the target time period, thereby realizing the control of the power converter. By using the method, the power control of a power converter can be realized by taking into account real-time operation data of each supercapacitor cell in a supercapacitor module in combination with the working state of each balancing circuit, such that the power of the power converter can change as the state of the supercapacitor cell changes, thereby improving the utilization rate of electric energy stored in the supercapacitor cell.

Description

Power control method and device of energy storage system 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 easily occur. An equalization circuit is usually needed 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 to solve 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 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 of the embodiments, the working states of the balancing circuits in the target period are determined according to the external DC bus voltage and real-time operation data, including:

[0011] The target power value is determined according to the difference between the preset bus voltage and the external DC bus voltage.

[0012] The target operation data of each super capacitor unit in the target period are obtained according to the target power value and the real-time operation data.

[0013] The working states of the balancing circuits in the target period are obtained based on the target operation data.

[0014] In one of the embodiments, the target operation data includes the target power value; the working states of the balancing circuits in the target period are obtained based on the target operation data, including:

[0015] The corresponding integral of each super capacitor unit in the target period is determined according to the target power value, and the corresponding integral of each super capacitor unit is used to represent the operation state of each super capacitor.

[0016] If the corresponding integral of the super capacitor unit is not in the preset interval, the balancing circuit corresponding to the super capacitor unit in the target period is in the enabled state.

[0017] If the corresponding integral of the super capacitor unit is in the preset interval, the balancing circuit corresponding to the super capacitor unit in the target period is in the disabled state.

[0018] In one of the embodiments, the power flow direction and the power size of the power converter in the target period are determined according to the external DC bus voltage and the working states of the balancing circuits in the target period, including:

[0019] The target power value is determined according to the difference between the preset bus voltage and the external DC bus voltage.

[0020] The power size of the power converter in the target period is determined based on the target power value, the external DC bus voltage and the working states of the balancing circuits in the target period.

[0021] In one of the embodiments, the power size of the power converter in the target period is determined based on the target power value, the external DC bus voltage and the working states of the balancing circuits in the target period, including:

[0022] In the case that the variance of the external DC bus voltage in the target period is greater than the preset variance, and each balancing circuit in the target period is in the disabled state, the target power value is determined as the power size of the power converter in the target period.

[0023] In one of the embodiments, the power size of the power converter in the target period is determined based on the target power value, the external DC bus voltage, and the working state of each balancing circuit in the target period, including:

[0024] If there is any balancing circuit in the enabled state in the target period, and the variance of the external DC bus voltage in the target period is less than or equal to the preset variance, the product of the proportional value and the target power value is taken as the power size of the power converter in the target period, and the proportional value is determined by the variance of the external DC bus voltage in the target period.

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

[0026] In one of the embodiments, the external DC bus voltage in the target period is obtained, including:

[0027] A prediction model for predicting the external DC bus voltage is constructed.

[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 application further provides a control unit, including a memory and a processor, 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 application further provides an energy storage system, which further includes a super capacitor module, a sampling circuit, a balancing circuit, and a power converter; the super capacitor module includes a plurality of super capacitor cells connected in series, each super capacitor cell is parallel connected with a sampling circuit, the sampling circuit is used to connect an external DC bus, each two adjacent super capacitor cells are parallel connected with a balancing circuit, and the power converter is connected between the super capacitor module and the external DC bus; the sampling circuit, the balancing circuit, and the power converter are connected with a control unit.

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

[0032] In a fourth aspect, the application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the above method.

[0033] The power control method and device of the energy storage system, by acquiring the external DC bus voltage in the target period and the real-time operation data of each super capacitor unit, determining the working state of each balancing circuit in the target period, and determining the power flow direction and power size of the power converter in the target period according to the external DC bus voltage and the working state of each balancing circuit in the target period, the control of the power converter is realized; 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 power in the super capacitor unit is improved. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the description of the embodiments of the present application or the related art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0035] Fig. 1 is a structural schematic diagram of an energy storage system in an embodiment;

[0036] Fig. 2 is a flow schematic diagram of a power control method of an energy storage system in an embodiment;

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

[0038] Fig. 4 is an internal structure diagram of a control unit in an embodiment. DETAILED DESCRIPTION

[0039] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the related drawings. The embodiments of the present application are shown in the drawings. However, the present application can be realized in many different forms, and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is 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 commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments of the present application, and are not intended to limit the present application.

[0041] As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", or the like, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0042] At present, the super capacitor is a new type of energy storage device, which has the dual characteristics of secondary battery and static capacitor, has the outstanding advantages of safe and reliable, high power density, fast charging, large discharge power, long service life, maintenance free, wide temperature range and clean environment, etc., and is particularly suitable for long life power supply, and is widely used in many fields such as distributed power generation and public transportation. Compared with the storage battery, the super capacitor can be put into use at a faster speed, and the influence caused by power failure is reduced, so it is widely used as a backup power supply, connected with a corresponding power converter, and connected to a DC bus.

[0043] However, due to the slight difference caused by production and other factors, the time for charging each super capacitor cell in the super capacitor to the rated voltage is not the same, and the situation of overvoltage or undervoltage of the capacitor is easy to occur, and it is usually necessary to set an equalization circuit to balance each super capacitor. The existing super capacitor converter control usually only considers the change of the overall state of the super capacitor and the state of the DC bus to design the control logic, and the charging and discharging power control process of the converter still needs to be improved, and there is a problem of low utilization rate of the energy stored in the super capacitor cell.

[0044] The power control method of the energy storage system provided by the embodiment of the present application can be applied to the energy storage system as shown in FIG. 1. Among them, the energy storage system includes a super capacitor module 11, a sampling circuit 12, an equalization circuit 13, a power converter 14 and a control unit 15; the super capacitor module 11 includes a plurality of super capacitor cells connected in series; each super capacitor cell is parallelly connected with one sampling circuit 12; the energy storage system is also provided with one sampling circuit 12 connected with an external DC bus; one equalization circuit 12 is parallelly connected between each two adjacent super capacitor cells; the power converter 14 is connected between the super capacitor module 11 and the external DC bus; the sampling circuit 12, the equalization circuit 13 and the power converter 14 are connected with the control unit 15.

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

[0046] In an exemplary embodiment, as shown in FIG. 2, a power control method of an energy storage system is provided, which is taken as an example to illustrate the application of the method to the energy storage system in FIG. 1, and the method includes:

[0047] S202, acquire the external DC bus voltage in the target period and the real-time running data of each super capacitor cell.

[0048] The target period can be set according to actual conditions, for example: if the super capacitor module is currently charging, the target period can be the period from the current time to the end of charging; correspondingly, if the super capacitor module is currently discharging, the target period can be the period from the current time to the end of discharging.

[0049] Specifically, the control unit can acquire the external DC bus voltage in the target period and the real-time running data of each super capacitor cell collected by the sampling circuit.

[0050] Exemplarily, the real-time running data of the super capacitor cell can include the voltage, current, power and remaining capacity of each super capacitor cell, which is not limited in the embodiment of the present application.

[0051] In one of the embodiments, the external DC bus voltage in the target period is acquired, including:

[0052] A prediction model for predicting the external DC bus voltage is constructed;

[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 can include the historical running data of the external DC bus (including the external DC bus voltage); and the prediction model can be a long short-term memory network model.

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

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

[0057] S204, determine the working state of each balancing circuit in the target period according to the external DC bus voltage and the real-time running data.

[0058] Specifically, the control unit can determine target operation data of each super capacitor monomer in the target period according to real-time operation data of each super capacitor monomer and an external DC bus voltage; and determine working states of the equalization circuits corresponding to each super capacitor monomer in the target period according to the target operation data.

[0059] In one of the embodiments, determining the working states of the equalization circuits in the target period according to the external DC bus voltage and the real-time operation data comprises:

[0060] determining the target power value according to a difference between the preset bus voltage and the external DC bus voltage;

[0061] obtaining the target operation data of each super capacitor monomer in the target period according to the target power value and the real-time operation data;

[0062] obtaining the working states of the equalization circuits in the target period based on the target operation data.

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

[0064] Specifically, the voltage of the DC bus can reflect the power generation of the (new energy) power grid. For example, in the case of sufficient light and high temperature, the DC bus voltage (external DC bus voltage) is usually higher than the standard bus voltage, at which time the super capacitor monomers as energy storage usually need to consume part of the electric energy. Conversely, the DC bus voltage is lower than the standard bus voltage, at which time the super capacitor monomers as energy storage usually need to supplement part of the electric energy to the DC bus. Therefore, the power required to be released or absorbed by the super capacitor module when the voltage of the DC bus is adjusted from the current voltage to the standard bus voltage can be determined in advance. After the voltage difference on the DC bus is measured, the target power value can be determined. Based on the real-time operation data of the current super capacitor monomers, the target operation data of each super capacitor monomer in the target period can be calculated after simulating operation according to the target power value. The working states of the equalization circuits in the target period are obtained based on the target operation data.

[0065] It should be noted that the power flow direction of the power converter connected to the super capacitor module can be determined by determining whether the super capacitor module needs to release or absorb power when the voltage of the DC bus is adjusted from the current voltage to the standard bus voltage.

[0066] In the embodiments of the present application, the target power value is determined according to the difference between the preset bus voltage and the external DC bus voltage, and the target running data of each super capacitor unit in the target period is obtained according to the target power value and real-time running data, and finally the working state of each balancing circuit in the target period is obtained, which is convenient for subsequent power control of the power converter and improves the utilization rate of the stored power in the super capacitor unit.

[0067] In one of the embodiments, the target running data includes a target power value; and the working state of each balancing circuit in the target period is obtained based on the target running data, including:

[0068] The integral corresponding to each super capacitor unit in the target period is determined according to the target power value, and the integral corresponding to each super capacitor unit is used to represent the running state of each super capacitor;

[0069] If the integral corresponding to the super capacitor unit is not in the preset interval, the balancing circuit corresponding to the super capacitor unit in the target period is in an enabled state;

[0070] If the integral corresponding to the super capacitor unit is in the preset interval, the balancing circuit corresponding to the super capacitor unit in the target period is in a disabled state.

[0071] The preset interval can be set according to actual conditions, which is not limited in the embodiments of the present application.

[0072] Specifically, if the integral corresponding to the super capacitor unit is not in the preset interval, it means that each super capacitor unit has the risk of overcharging or overdischarging, and the working state of the balancing circuit corresponding to each super capacitor unit is in an enabled state; if the integral corresponding to the super capacitor unit is in the preset interval, it means that each super capacitor unit does not have the risk of overcharging or overdischarging, and the working state of the balancing circuit corresponding to each super capacitor unit is in a disabled state.

[0073] It should be noted that the integral corresponding to each super capacitor unit in the target period can be obtained by obtaining the power curve corresponding to the super capacitor unit and integrating the power curve with respect to time.

[0074] S206, according to the external DC bus voltage and the working state of each balancing circuit in the target period, determine the power flow direction and power size of the power converter in the target period.

[0075] Specifically, the control unit can determine the power flow direction and power size of the power converter in the target period according to the external DC bus voltage and the working state of each balancing circuit in the target period.

[0076] In one of the embodiments, the power flow direction and the power size of the power converter in the target period are determined according to the external DC bus voltage, and the working states of the balancing circuits in the target period, including:

[0077] The target power value is determined according to the difference between the preset bus voltage and the external DC bus voltage.

[0078] The power size of the power converter in the target period is determined based on the target power value, the external DC bus voltage, and the working states of the balancing circuits in the target period.

[0079] Specifically, the control unit can first determine the initial target power value according to the difference between the preset bus voltage and the external DC bus voltage, and then determine the power size of the power converter in the target period based on the target power value, the external DC bus voltage, and the working states of the balancing circuits in the target period.

[0080] In the embodiments of the present application, the power size of the power converter in the target period is determined based on the target power value, the external DC bus voltage, and the working states of the balancing circuits in the target period, so that the power control of the power converter can be performed subsequently, and the power converter can change with the change of the super capacitor unit, thereby improving the utilization rate of the stored power in the super capacitor unit.

[0081] In one of the embodiments, the power size of the power converter in the target period is determined based on the target power value, the external DC bus voltage, and the working states of the balancing circuits in the target period, including:

[0082] In the case that the variance of the external DC bus voltage in the target period is greater than the preset variance, and each balancing circuit in the target period is in the disabled state, the target power value is determined as the power size of the power converter in the target period.

[0083] The method of obtaining the variance of the external DC bus voltage is the existing method, which is not limited in the embodiments of the present application; the preset variance can be set according to the actual situation, which is not limited in the embodiments of the present application.

[0084] Specifically, the variance of the external DC bus voltage in the target period is greater than the preset variance, and each balancing circuit in the target period is in the disabled state, which can be represented as the new energy power generation system connected to the external DC bus has large fluctuations, and energy needs to be supplemented or absorbed, and there is no risk of overcharging or overdischarging of the super capacitor module at this time, so the target power value can be used as the power size of the power converter in the target period.

[0085] In the embodiments of the present application, the power size of the power converter in the target period is determined by considering the state of the external DC bus and the operating state of the supercapacitor unit (the operating state of the balancing circuit), so that the power size of the power converter can change with the change of the supercapacitor unit, and the utilization rate of the electrical energy stored in the supercapacitor unit is improved.

[0086] In one of the embodiments, the power size of the power converter in the target period is determined based on the target power value, the external DC bus voltage, and the working state of each balancing circuit in the target period, and includes:

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

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

[0089] The proportional value can be set according to the actual situation, and in the embodiments of the present application, the proportional value is less than 1.

[0090] Specifically, when the working state of the balancing circuit is in the enabled state, it means that there is a risk of overcharging or overdischarging of the supercapacitor module, and at this time, the charging power or discharging power of the power converter is reduced according to the proportional value; the proportional value k can be obtained by the following formula:

[0091]

[0092] Wherein, σ 2 represents the variance of the external DC bus voltage; represents the preset variance.

[0093] For example, when the working state of the balancing circuit in the target period is in the enabled state, and the variance of the external DC bus voltage in the target period is greater than the preset variance, the difference between the external DC bus voltage and the standard bus voltage at each time in the target period can be calculated, if the difference is greater than the preset difference, the target power value is used, if the difference is not greater than the preset difference, the product of the target power value and the proportional value is used; the preset difference can be set according to the actual situation, and in the embodiments of the present application, it is not limited.

[0094] When the working states of the balancing circuits are all enabled states in the target 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 in the target period is directly determined according to the residual charging capacity or residual discharging capacity and the current working voltage of each super capacitor unit; specifically, each super capacitor unit stops outputting after reaching the maximum or minimum cutoff voltage, and the integral value of the power size of the power converter in the target period in the target period is not greater than the sum of the residual charging capacity or the residual discharging capacity of each super capacitor unit.

[0095] In the embodiments of the present application, by considering the state of the external DC bus and combining the running state of the super capacitor unit (the running state of the balancing circuit), the power size of the power converter in the target period is determined, so that it 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.

[0096] S208, control the power converter based on the power flow direction and the power size.

[0097] Specifically, after obtaining the power flow direction and the power size, the control unit can modulate the signal of the corresponding duty cycle to the gate of each switch tube in the power converter through a conventional logic circuit, so as to control 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 energy storage system, the working state of each balancing circuit in the target period is determined according to the obtained external DC bus voltage in the target period and the real-time running data of each super capacitor unit, and the power flow direction and the power size of the power converter in the target period are determined according to the external DC bus voltage and the working state of each balancing circuit in the target period, so as to control the power converter, so that it 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.

[0100] It should be understood that although the steps in the flowcharts involved in the embodiments described above are shown in sequence according to the arrows, the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, the execution of the steps is not strictly limited in sequence, and the steps can be executed in other orders. Moreover, at least some of the steps in the flowcharts involved in the embodiments described above can include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of the steps or stages is not necessarily sequential, but can be alternately executed with at least part of other steps or steps or stages in other steps.

[0101] Based on the same inventive concept, the embodiments of the present application also provide a power control device of a power storage system for implementing the power control method of the power storage system described above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more power control device embodiments of the power storage system provided below can refer to the limitations of the power control method of the power storage system described above, which will not be repeated here.

[0102] In an exemplary embodiment, as shown in FIG. 3, a power control device 300 of a power storage system is provided, which is applied to a control unit in the power storage system, and the power storage system further includes a super capacitor module, a sampling circuit, an equalization circuit and a power converter; the super capacitor module includes a plurality of super capacitor cells connected in series, each of which is connected in parallel with a sampling circuit, the sampling circuit is used to connect an external DC bus, each two adjacent super capacitor cells are connected in parallel with an equalization circuit, and the power converter is connected between the super capacitor module and the external DC bus; the sampling circuit, the equalization circuit and the power converter are connected with the control unit; the device 300 includes:

[0103] The acquisition module 301 is configured to acquire the real-time running data of each super capacitor cell and the external DC bus voltage in a target period.

[0104] The state determination module 302 is configured to determine the working state of each equalization circuit in the target period according to the external DC bus voltage and the real-time running data.

[0105] The power determination module 303 is configured to determine the power flow direction and 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.

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

[0107] In one of the embodiments, the state determining module 302 is further configured to determine the target power value according to a difference between the preset bus voltage and the external DC bus voltage.

[0108] According to the target power value and the real-time operation data, target operation data of each super capacitor unit in the target period is obtained.

[0109] Based on the target operation data, working states of each balancing circuit in the target period are obtained.

[0110] In one of the embodiments, the target operation data includes the target power value; the state determining module 302 is further configured to determine a corresponding integral of each super capacitor unit in the target period according to the target power value, the corresponding integral of each super capacitor unit being used to represent an operation state of each super capacitor.

[0111] If the corresponding integral of each super capacitor unit is not in the preset interval, the balancing circuit corresponding to the super capacitor unit is in an enabled state in the target period.

[0112] If the corresponding integral of each super capacitor unit is in the preset interval, the balancing circuit corresponding to the super capacitor unit is in a disabled state in the target period.

[0113] In one of the embodiments, the power determining module 303 is further configured to determine the target power value according to a difference between the preset bus voltage and the external DC bus voltage.

[0114] Based on the target power value, the external DC bus voltage and the working states of each balancing circuit in the target period, a power size of the power converter in the target period is determined.

[0115] In one of the embodiments, the power determining module 303 is further configured to determine the target power value as the power size of the power converter in the target period, if a variance of the external DC bus voltage in the target period is greater than a preset variance and each balancing circuit in the target period is in the disabled state.

[0116] In one of the embodiments, the power determining module 303 is further configured to, if any balancing circuit in the target period is in the enabled state and the variance of the external DC bus voltage in the target period is less than or equal to the preset variance, take a product of a proportional value and the target power value as the power size of the power converter in the target period, the proportional value being determined according to the variance of the external DC bus voltage in the target period.

[0117] If each balancing circuit in the target period is in the enabled state, the power size of the power converter in the target period is determined according to the target operation data.

[0118] In one of the embodiments, the obtaining 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] The above-mentioned modules in the power control device of the energy storage system can be implemented by software, hardware, or a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory in the computer device in software form, so as to be called and executed by the processor to perform the operations corresponding to the above-mentioned modules.

[0121] In one of the exemplary embodiments, a control unit is provided, including a memory and a processor, the memory storing a computer program, and the processor implementing the steps of the above-mentioned method when executing the computer program.

[0122] Specifically, as shown in FIG. 4, the control unit 4 can include a processor 40, a memory 41, and a computer program 42 stored in the memory 41 and executable on the processor 40. The processor 40 implements the steps in the above-mentioned power control method of the energy storage system when executing the computer program 42, such as the steps shown in FIG. 2. Alternatively, the processor 40 can implement the functions of the modules / units in the above-mentioned system embodiments when executing the computer program 42, such as the functions of the modules shown in FIG. 3.

[0123] For example, the computer program 42 can be divided into one or more modules / units, which are stored in the memory 41 and executed by the processor 40 to complete the present application. One or more modules / units can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program 42 in the control unit 4.

[0124] The control unit 4 can be a terminal or a server, and the control unit 4 can include, but is not limited to, the processor 40 and the memory 41. Those skilled in the art can understand that FIG. 4 is only an example of the control unit 4, and does not limit the control unit 4, which can include more or fewer components than shown, or combine certain components, or different components, such as a terminal which can also include an input / output device, a network access device, a bus, etc.

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

[0126] The memory 41 can be an internal storage unit of the control unit 4, such as a hard disk or a 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 disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory 41 can include both the internal storage unit and the external storage device of the control unit 4. 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 will be output.

[0127] Exemplarily, the control unit can be a server, and the control unit (computer device) includes a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output 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 an 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 operating system and the computer program in the non-volatile storage medium to run. The database of the computer device is used to store external DC bus voltage and real-time running data. 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 terminals outside through network connection. The computer program is executed by the processor to implement a power control method of an energy storage system.

[0128] The control unit can also be a terminal, and the control unit (computer device) includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output 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 an 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 the computer program in the non-volatile storage medium to run. 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 in a wired or wireless manner. The wireless manner can be achieved through WIFI, mobile cellular network, near field communication (NFC) or other technologies. The computer program is executed by the processor to implement a power control method of an energy storage system.

[0129] In one exemplary embodiment, an energy storage system is provided, and the energy storage system further includes a super capacitor module, a sampling circuit, an equalization circuit and a power converter; the super capacitor module includes a plurality of super capacitor cells connected in series, each super capacitor cell has a sampling circuit connected in parallel thereto, the sampling circuit is used to connect an external DC bus, each two adjacent super capacitor cells have an equalization circuit connected in parallel therebetween, and the power converter is connected between the super capacitor module and the external DC bus; the sampling circuit, the equalization circuit and the power converter are connected to a control unit.

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

[0131] Specifically, as shown in FIG. 1, the energy storage system includes a super capacitor module 11, a sampling circuit 12, an equalization circuit 13, a power converter 14 and a control unit 15; the super capacitor module 11 includes a plurality of super capacitor cells connected in series; each super capacitor cell has a sampling circuit 12 connected in parallel thereto; the energy storage system is further provided with a sampling circuit 12 connected to an external DC bus; each two adjacent super capacitor cells have an equalization circuit 12 connected in parallel therebetween; the power converter 14 is connected between the super capacitor module 11 and the external DC bus; the sampling circuit 12, the equalization circuit 13 and the power converter 14 are connected to the control unit 15.

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

[0133] It should be noted that the sampling circuit 12 can be used to collect real-time operation data of each super capacitor unit and operation data of the DC bus in real time and send them to the control unit 15; the control unit can be an MCU (Micro Controller Unit), a single-chip microcomputer, etc., which is not limited here. The equalization circuit 13 can be used to equalize the two connected super capacitor units according to the working state, so as to avoid overcharging or overdischarging of the super capacitor units during charging and discharging.

[0134] In one embodiment, a computer readable storage medium is provided, and the computer readable storage medium stores a computer program. The computer program is executed by a processor to implement the power control method of the energy storage system.

[0135] Exemplarily, as shown in FIG. 4, the computer readable storage medium can store a computer program 42, the computer program 42 includes program instructions, and the program instructions are executed by a processor 40 to implement all or part of the processes in the above-mentioned embodiment method. The computer program 42 can also be used to instruct related hardware to complete, and the computer program 42 can be stored in a computer readable storage medium. When the computer program 42 is executed by the processor 40, the steps of each method embodiment can be implemented. The computer program 42 includes computer program code, which can be in the form of source code, object code, executable files or some intermediate forms, etc. The computer readable medium can include any entity or device capable of carrying computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, electrical signal and software distribution medium, etc.

[0136] The computer readable storage medium can be an internal storage unit of the terminal of any of the foregoing embodiments, such as a hard disk or a memory of the terminal. The computer readable storage medium can also be an external storage device of the terminal, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the computer readable storage medium can include both the internal storage unit and the external storage device of the terminal. 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 will be output.

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

[0138] It can be understood by those skilled in the art that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing related hardware through a computer program, and 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 above-mentioned embodiments of each method. In the embodiments provided in the present application, any reference to memory, database or other medium can include at least one of non-volatile memory and volatile memory. The non-volatile memory can include read-only memory (Read-Only Memory, ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (Resistive Random Access Memory, ReRAM), magnetoresistive random access memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric memory (Ferroelectric Random Access Memory, FRAM), phase change memory (Phase Change Memory, PCM), graphene memory, etc. The volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, etc. As an illustration but not limitation, the RAM can be in various forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (Artificial Intelligence, AI) processor, etc., without being limited thereto.

[0139] The technical features of the above embodiments can be combined in any way. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0140] The above-described embodiments are merely illustrative of several embodiments of the present application, which are described in more detail and in a specific manner, but should not be construed as limiting the scope of the patent of the present application. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A power control method for an energy storage system, characterized in that, A control unit is applied to the energy storage system, which further includes a supercapacitor module, a sampling circuit, an equalization circuit, and a power converter. The supercapacitor module comprises multiple supercapacitor cells connected in series, each supercapacitor cell having the sampling circuit connected in parallel. The sampling circuit is used to connect to an external DC bus. The equalization 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 equalization circuit, and the power converter are all connected to the control unit. The method includes: Acquire the external DC bus voltage and the real-time operating data of each supercapacitor cell within the target time period; Based on the external DC bus voltage and the real-time operating data, determine the operating status of each equalization circuit within the target time period; Based on the external DC bus voltage and the operating status of each equalization circuit during the target time period, the power flow direction and power magnitude of the power converter during the target time period are determined. 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 step of determining the operating status of each equalization circuit within the target time period based on the external DC bus voltage and the real-time operating data includes: The target power value is determined based on the difference between the preset bus voltage and the external DC bus voltage; Based on the target power value and the real-time operating data, the target operating data of each supercapacitor cell within the target time period is obtained; Based on the target operating data, the operating status of each equalization circuit within the target time period is obtained.

3. The method according to claim 2, characterized in that, The target operating data includes the target power value; obtaining the operating status of each equalization circuit within the target time period based on the target operating data includes: The integral corresponding to each supercapacitor cell within the target time period is determined based on the target power value, and the integral corresponding to each supercapacitor cell is used to characterize the operating status of each supercapacitor. If the integral corresponding to the supercapacitor cell is not within the preset range, the equalization circuit corresponding to the supercapacitor cell is in the enabled state during the target time period. If the integral corresponding to the supercapacitor cell is within the preset range, then the equalization circuit corresponding to the supercapacitor cell is in a deactivated state during the target time period.

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

5. The method according to claim 4, characterized in that, The step of 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 status of each equalization circuit within the target time period includes: If the variance of the external DC bus voltage during the target time period is greater than a preset variance, and all the equalization circuits during the target time period are in a deactivated state, the target power value is determined as the power of the power converter during the target time period.

6. The method according to claim 4, characterized in that, The step of 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 status of each equalization circuit within the target time period includes: If any of the equalization circuits is enabled during the target time period, and the variance of the external DC bus voltage during the target time period is less than or equal to a preset variance, then the product of the proportional value and the target power value is used as the power of the power converter during the target time period. The proportional value is determined by the variance of the external DC bus voltage during the target time period. If the equalization circuit is enabled during the target time period, the power of the power converter during the target time period is determined based on the target operating data.

7. The method according to claim 1, characterized in that, The acquisition of the external DC bus voltage within the target time period includes: Construct a prediction model for predicting the voltage of the external DC bus; Voltage data from historical periods are input into the prediction model to obtain the external DC bus voltage for the target period, wherein the historical periods are periods preceding the target period.

8. A control unit comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

9. An energy storage system, characterized in that, The energy storage system further includes a supercapacitor module, a sampling circuit, an equalization circuit, and a power converter. The supercapacitor module comprises multiple supercapacitor cells connected in series, and each supercapacitor cell is connected in parallel with the sampling circuit, which is used to connect to an external DC bus. The equalization 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 equalization circuit, and the power converter are all connected to the control unit. The control unit is used to perform 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, it implements the steps of the method according to any one of claims 1 to 7.

Images