Energy storage system, control method thereof and energy storage station

Abstract

An energy storage system, a control method thereof and an energy storage station belong to the technical field of power electronics, and comprise at least one energy storage module, a conversion module and at least one battery management module. The energy storage module comprises a plurality of batteries; the conversion module is periodically self-awakened and outputs a second voltage based on the first voltage of the at least one energy storage module under the awakening condition; each battery management module performs equalization control processing on the plurality of batteries in the at least one energy storage module in one-to-one correspondence under the excitation of the second voltage; therefore, each battery cluster has a long-term internal automatic balance adjustment capability before merging (such as a transportation process), the consistency of each battery during debugging and operation is improved, debugging equipment is simplified, an additional power supply for charging is not needed, a fuse can be used, and a high-temperature wire is not needed to prevent wire skin from melting and sparking, so that the cost is relatively low, and the reliability is high.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power electronics, and particularly relates to an energy storage system and a control method thereof and an energy storage station. BACKGROUND

[0002] The related energy storage system ensures the safety and reliability of the multi-battery cluster incorporation according to the sequence of the incorporation of each battery cluster into the total positive and total negative and the consistency of the state through the energy complementation between the battery clusters, adopts short-time large-current charging and discharging, but does not involve the consistency of the internal state of each battery cluster before the incorporation (such as the transportation process) and does not have the long-term internal automatic balancing and adjusting capability, thus causing the following problems:

[0003] 1. The energy storage module is usually transported for 6 to 12 months from the production and factory delivery to the destination, the self-discharge difference of the battery cell leads to the too large difference of the battery;

[0004] 2. The on-site debugging often adopts the generator to provide the auxiliary source debugging, the auxiliary power supply cannot be continuously provided, and the system cannot work;

[0005] 3. In view of the above reasons, the difference of the battery cell is too large, the balancing time is short, the consistency of each battery cell in the energy storage module cannot be adjusted to meet the system requirement at the time of acceptance, at this time, the additional power supply needs to be supplemented, the supplementing current needs to be 3A to 5A, the sampling line cannot use the fine line scheme, and the fuse cannot be used, the sampling line needs to use the high-temperature line to prevent the line skin from melting and sparking, and the cost is high.

[0006] Therefore, it is urgent to provide an energy storage system to have the long-term internal automatic balancing and adjusting capability for each battery cluster before the incorporation (such as the transportation process). SUMMARY

[0007] In view of the above problems, the application provides an energy storage system and a control method thereof and an energy storage station, and aims to solve the problem that the related energy storage system does not have the long-term internal automatic balancing and adjusting capability for each battery cluster before the incorporation (such as the transportation process).

[0008] In a first aspect, the application provides an energy storage system provided by the embodiments of the application, which comprises at least one energy storage module, a conversion module and at least one battery management module; the energy storage module comprises a plurality of batteries;

[0009] The conversion module is connected with the at least one energy storage module, is configured to be periodically awakened, and in the case of awakening, outputs a second voltage based on a first voltage of the at least one energy storage module;

[0010] The at least one battery management module is connected with the conversion module and one-to-one connected with the at least one energy storage module, and the at least one battery management module is configured to perform equalization control processing on a plurality of batteries in the corresponding at least one energy storage module under the excitation of the second voltage.

[0011] In the technical scheme of the embodiment, the conversion module periodically wakes up, and the first voltage of at least one of the energy storage modules is converted into the second voltage under the condition of waking up, and each battery management module performs equalization control processing on a plurality of batteries in the corresponding energy storage module under the excitation of the second voltage; therefore, the internal equalization of the energy storage module (battery cluster) is periodically performed before the energy storage module is integrated (for example, during transportation), so that the difference between the batteries is small when the energy storage module is delivered to debugging and put into operation after more than half a year; the first voltage of at least one of the energy storage modules is used as a power supply by the conversion module, and the debugging is performed by using self power, so that a generator is not needed to provide auxiliary power for debugging, the debugging equipment is simplified, the cost is reduced, and the flexibility of on-site debugging is improved; the consistency of each battery cell in the energy storage module can meet the system requirements during acceptance, an additional power supply is not needed to supplement power, the debugging workload is reduced, a fuse can be used, and a high-temperature wire is not needed to prevent the wire from melting and sparking, so that the cost is low and the reliability is high.

[0012] In some embodiments, the conversion module is multiple, the battery management module is multiple, and the energy storage module is multiple;

[0013] Each of the conversion modules is connected with at least one of the energy storage modules and is configured to periodically wake up and output the second voltage based on the first voltage of the at least one energy storage module under the condition of waking up;

[0014] Each of the battery management modules is connected with one of the conversion modules and one-to-one connected with each of the energy storage modules, and each of the battery management modules is configured to perform equalization control processing on a plurality of batteries in the corresponding multiple energy storage modules under the excitation of the second voltage.

[0015] By using the above scheme, the conversion module is multiple, the load capacity is improved, and the number of energy storage modules that are periodically internally equalized is improved.

[0016] In some embodiments, the energy storage module includes a plurality of energy storage units, the energy storage unit includes at least one battery, the battery management module includes a battery control unit and a plurality of battery detection units, and the plurality of battery detection units are one-to-one connected with the plurality of energy storage units.

[0017] The battery control unit is connected with the plurality of battery detection units and the conversion module, and is configured to trigger the battery detection unit to suspend or resume the balancing processing of the corresponding energy storage unit under the excitation of the second voltage.

[0018] By using the above scheme, the battery detection unit is controlled to suspend or resume the balancing processing of the corresponding energy storage unit, so that the balancing control of each energy storage unit in the energy storage module is realized.

[0019] In some embodiments, the plurality of battery detection units includes a first target battery detection unit, and the plurality of energy storage units includes a first target energy storage unit; the battery control unit is specifically configured to send first control information to the first target battery detection unit under the excitation of the second voltage; the first control information is used to trigger the first target detection unit to suspend the balancing processing of the plurality of batteries in the first target energy storage unit.

[0020] The difference between the real-time first voltage of the first target energy storage unit and the voltage of the energy storage unit with the largest real-time first voltage in the same energy storage module is greater than a threshold value; and the first target battery detection unit is a battery detection unit connected with the first target energy storage unit.

[0021] By using the above scheme, the balancing processing of the energy storage unit with the difference between the real-time first voltage and the voltage of the energy storage unit with the largest real-time first voltage in the same energy storage module greater than a threshold value is suspended, so that the energy storage unit with smaller first voltage in the energy storage module suspends the balancing processing, while the energy storage unit with larger first voltage in the energy storage module maintains the balancing processing. After the balancing of the battery, the first voltage of the energy storage unit is reduced, thereby improving the consistency of each energy storage unit and the consistency of each battery in each energy storage unit.

[0022] In some embodiments, the plurality of battery detection units includes a second target battery detection unit, and the plurality of energy storage units includes a second target energy storage unit; the battery control unit is further configured to send second control information to the second target battery detection unit under the excitation of the second voltage, and the second control information is used to trigger the second target detection unit to resume the balancing processing of the plurality of batteries in the second target energy storage unit.

[0023] The second target energy storage unit is an energy storage unit whose difference between the real-time first voltage and the voltage of the energy storage unit with the largest real-time first voltage in the same energy storage module is less than or equal to a threshold value, and the balancing processing of the energy storage unit is suspended; and the second target battery detection unit is the battery detection unit connected with the second target energy storage unit.

[0024] By adopting the above scheme, the resumption of the equalization processing on the suspended equalization processing energy storage unit with the voltage difference between the real-time first voltage and the voltage of the energy storage unit with the maximum first voltage in the same energy storage module being less than or equal to the threshold value is realized, so that when the first voltage of the suspended equalization processing energy storage unit is high, the equalization processing is resumed, and the first voltage of the suspended equalization processing energy storage unit is dynamically adjusted in real time, thereby further improving the consistency of each energy storage unit and the consistency of each battery in each energy storage unit.

[0025] In some embodiments, a direct current bus is further included.

[0026] At least one of the energy storage modules is connected to the direct current bus in an on-off manner.

[0027] The conversion module is connected to the direct current bus and at least one of the energy storage modules, and is specifically configured to periodically wake up for a preset time length, and convert the first voltage of one of the energy storage modules or the voltage of the direct current bus into the second voltage in the case of waking up.

[0028] By adopting the above scheme, the conversion module uses the first voltage of one of the energy storage modules or the voltage of the direct current bus as a power supply, thereby improving the flexibility of power supply selection.

[0029] In some embodiments, a power distribution module is further included.

[0030] The power distribution module is connected to the conversion module, the direct current bus and at least one of the energy storage modules, and is configured to transmit the voltage of the direct current bus to the conversion module in response to a first condition.

[0031] The first condition includes that the difference between the voltage of each of the energy storage modules and the voltage of the direct current bus is less than or equal to a first preset voltage.

[0032] By adopting the above scheme, power is preferentially taken from the direct current bus.

[0033] In some embodiments, the power distribution module is further configured to transmit the first voltage of the energy storage module with the maximum voltage to the conversion module in response to a second condition.

[0034] The second condition includes that the difference between the first voltage of at least one of the energy storage modules and the voltage of the direct current bus is greater than the first preset voltage.

[0035] By adopting the above scheme, when the voltage of the direct current bus is insufficient, power is taken from the energy storage module with the highest voltage, thereby realizing the voltage balance of each energy storage module and improving the system utilization rate and reliability.

[0036] In some embodiments, the power distribution module comprises a first diode, a plurality of second diodes, and a plurality of third diodes;

[0037] The positive electrode of the first diode constitutes a voltage input end of a DC bus of the power distribution module, and is connected to the DC bus to access the voltage of the DC bus;

[0038] Each second diode constitutes a first voltage input end of each energy storage module of the power distribution module, and is connected to each energy storage module in one-to-one correspondence to access the first voltage of each energy storage module;

[0039] The negative electrode of each second diode is connected to the positive electrode of each third diode in one-to-one correspondence;

[0040] The negative electrode of each third diode is connected to the negative electrode of the first diode and constitutes a second voltage output end of the power distribution module, and the second voltage output end is connected to each battery management module to output the second voltage.

[0041] By adopting the above scheme, the power is preferentially taken from the DC bus by means of circuit topology, and when the voltage of the DC bus is insufficient, the power is taken from the energy storage module with the highest voltage, which does not require software configuration, has high reliability and low cost.

[0042] In some embodiments, further comprising a first switch and a second switch;

[0043] The first end of each first switch is connected to each energy storage module in one-to-one correspondence;

[0044] The second end of each first switch is connected to the first end of each second switch in one-to-one correspondence;

[0045] The second end of each second switch is connected to the DC bus.

[0046] By adopting the above scheme, each energy storage module can be connected to the DC bus in an on-off manner.

[0047] In some embodiments, further comprising:

[0048] A battery management system connected to each energy storage module and the conversion module, respectively, the battery management system being configured to control the equalization of each energy storage module according to the second voltage.

[0049] By adopting the above scheme, the equalization between each energy storage module is realized, and the difference between each energy storage module is small when debugging and putting into operation, further improving the reliability and safety of the energy storage system.

[0050] In some embodiments, further comprising:

[0051] an external power supply for providing alternating current;

[0052] the conversion module is connected with at least one of the energy storage modules and the external power supply;

[0053] the conversion module is specifically configured to periodically wake up for a preset time length, and convert the first voltage of one of the energy storage modules or the alternating current into the second voltage in the case of waking up.

[0054] By adopting the above scheme, the external power supply is used as the system power supply, and the flexibility of power supply selection is improved.

[0055] The embodiment of the application further provides a control method applied to the energy storage system.

[0056] the conversion module periodically wakes up;

[0057] in the case of waking up, the conversion module outputs the second voltage based on the first voltage of at least one of the energy storage modules, to supply power to each battery management module;

[0058] The battery management module is used to perform balancing control processing on a plurality of batteries in the at least one energy storage module corresponding to the battery management module under the excitation of the second voltage.

[0059] By adopting the above scheme, the balancing of the energy storage modules (battery clusters) is periodically performed before the energy storage modules are integrated (for example, during transportation), the consistency of each battery during debugging and operation is improved, the debugging equipment is simplified, no additional power supply is needed, a fuse can be used and a high-temperature wire is not needed to prevent the wire skin from melting and sparking, so that the cost is low and the reliability is high.

[0060] In some embodiments, the energy storage system further comprises a direct-current bus; and at least one of the energy storage modules is connected to the direct-current bus in an on-off manner.

[0061] in the case of waking up, the conversion module outputs the second voltage based on the first voltage of at least one of the energy storage modules, to supply power to each battery management module;

[0062] in the case of waking up, the conversion module converts the first voltage of one of the energy storage modules or the voltage of the direct-current bus into the second voltage.

[0063] By adopting the above scheme, the conversion module uses the first voltage of one of the energy storage modules or the voltage of the direct-current bus as the power supply, and the flexibility of power supply selection is improved.

[0064] In a second aspect, the embodiments of the present application further provide a storage station, which comprises the storage system as described above.

[0065] The above description is only a summary of the technical solutions of the present application. In order to make the technical means of the present application more clearly understood and implemented according to the content of the description, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0066] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not meant to limit the present application. Moreover, the same reference numerals in all the drawings represent the same elements. In the drawings:

[0067] Figure 1 A structural schematic diagram of a storage system according to an embodiment of the present application;

[0068] Figure 2 Another structural schematic diagram of a storage system according to an embodiment of the present application;

[0069] Figure 3 Another structural schematic diagram of a storage system according to an embodiment of the present application;

[0070] Figure 4 Another structural schematic diagram of a storage system according to an embodiment of the present application;

[0071] Figure 5 Another structural schematic diagram of a storage system according to an embodiment of the present application;

[0072] Figure 6 A schematic circuit diagram of a power distribution module in a storage system according to an embodiment of the present application;

[0073] Figure 7 Another structural schematic diagram of a storage system according to an embodiment of the present application;

[0074] Figure 8 Another structural schematic diagram of a storage system according to an embodiment of the present application. DETAILED DESCRIPTION

[0075] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0076] 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 this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the use of the terms "including," "comprising," or "having" and variations thereof herein is intended to be broad and encompass the terms "consisting of" and "consisting essentially of" and variations thereof. Unless otherwise noted, the terms "including" and "comprising" are open-ended and do not exclude the presence of unrecited elements or limitations.

[0077] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0078] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0079] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0080] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0081] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as limiting the embodiments of the present application. The orientation or position of the device or element indicated, and therefore cannot be understood as limiting the embodiments of the present application.

[0082] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0083] Currently, judging from market trends, the application of energy storage power systems is becoming increasingly widespread. Energy storage power systems are widely used in the power transmission and distribution network sector. As the application areas of energy storage power systems continue to expand, the market demand for them is also constantly increasing.

[0084] With the widespread application of energy storage power systems in power transmission and distribution networks, ensuring the consistency of batteries from delivery to commissioning and operation has become a pressing social issue. The relevant energy storage system includes: N energy storage battery clusters, where N is a positive integer; N energy storage battery cluster management modules, each corresponding to one of the energy storage battery clusters, used to collect the status information of its corresponding cluster; a system management controller, used to issue control signals based on the collected status information of the N energy storage battery clusters, enabling the cluster management modules to control their corresponding clusters; and a DC-DC converter, used to perform charging / discharging operations based on the control signals. This circuit enables mutual energy replenishment between energy storage battery clusters within the energy storage system through energy transfer, ultimately achieving state consistency. It prevents high-surge circulating current impacts between parallel battery clusters, ensuring the safety and reliability of multiple battery clusters connected in parallel. However, this energy storage system only balances the individual battery clusters (energy storage modules) during the commissioning phase, and cannot guarantee the consistency of the internal state of each battery cluster before commissioning (before integration), resulting in poor reliability and safety.

[0085] To address the issues of poor reliability and safety, research has found that before integration (such as during transportation), the design can incorporate a conversion module that periodically self-wakes up for a preset duration. Upon wake-up, the first voltage of at least one of the energy storage modules is converted to a second voltage to incentivize the battery management module to perform equalization control on multiple batteries within the corresponding energy storage module, thereby improving reliability and safety.

[0086] According to some embodiments of this application, refer to Figure 1 , Figure 1 A schematic diagram of an energy storage system according to an embodiment of this application is shown. For ease of explanation, only the parts relevant to this embodiment are shown, and are described in detail below:

[0087] The above energy storage system comprises at least one energy storage module 11, a conversion module 12 and at least one battery management module 13; the energy storage module 11 comprises a plurality of batteries.

[0088] The conversion module 12 is connected with the at least one energy storage module 11, is configured to periodically wake up, and outputs a second voltage based on a first voltage of the at least one energy storage module 11 when the conversion module 12 wakes up.

[0089] The at least one battery management module 13 is connected with the conversion module 12 and is connected with the at least one energy storage module 11 one by one, and the at least one battery management module 13 is configured to perform balancing control processing on the plurality of batteries in the corresponding at least one energy storage module 11 under the excitation of the second voltage.

[0090] It can be understood that the conversion module 12 can be a direct current conversion module 12. The energy storage module 11 comprises a battery, and the battery internally comprises a battery cell and a copper bar or a wire harness and the like for realizing high-voltage connection.

[0091] By setting a conversion module 12 for the at least one energy storage module 11, the conversion module 12 is powered by the first voltage of the energy storage module 11 itself and is connected with the control system (battery management module 13) of each energy storage module 11 to supply power to each battery management module 13. The conversion module 12 wakes up every second time length (T2) and works for a second time length (T2), and each battery management module 13 starts to work during the wake-up period, analyzes and calculates the information state of each battery in the energy storage module 11, judges the opening or closing of internal balancing, and issues corresponding instructions. By this way of periodic hibernation and start and self-power supply, the possibility of too large battery difference can be reduced, the possibility of on-site power compensation can be reduced, the operation flexibility can be improved, and the debugging workload can be reduced; at the same time, the balancing overcurrent capacity can be reduced from more than 3A to less than or equal to 200mA, and the line cross-section specification can be greatly reduced.

[0092] Since the conversion module 12 periodically wakes up by itself and converts the first voltage of at least one of the energy storage modules 11 into the second voltage when it wakes up, each battery management module 13 performs balancing control processing on the multiple batteries in the corresponding energy storage module 11 under the excitation of the second voltage; therefore, the balancing inside the energy storage module 11 (battery cluster) is periodically performed before the energy storage module 11 is integrated (such as during transportation); so that the difference between each battery is small when the energy storage module 11 is shipped to debugging and put into operation after more than half a year; and the conversion module 12 uses the first voltage of at least one of the energy storage modules 11 as a power supply to debug by itself, so that the on-site debugging does not need to use a generator to provide auxiliary power for debugging, which simplifies the debugging equipment, reduces the cost, and improves the flexibility of on-site debugging; the consistency of each cell in the energy storage module 11 can meet the system requirements during acceptance, without the need for additional power supply, which reduces the debugging workload, and the use of fuses without high-temperature wires to prevent wire melting and sparking, so the cost is lower and the reliability is higher.

[0093] In some embodiments, optionally, the conversion module is multiple, the battery management module is multiple, and the energy storage module is multiple.

[0094] Each conversion module is connected with at least one energy storage module and is configured to periodically wake up by itself and output a second voltage based on the first voltage of at least one energy storage module when it wakes up.

[0095] Each battery management module is connected with a conversion module and is connected with each energy storage module one-to-one, and each battery management module is configured to perform balancing control processing on multiple batteries in the corresponding energy storage module under the excitation of the second voltage.

[0096] It should be noted that each conversion module can be connected with one or more energy storage modules, and each conversion module is also connected with one or more battery management modules, and the power supply of each battery management module can be flexibly set.

[0097] By using the above scheme, the conversion module is multiple, which improves the load capacity and thus improves the number of energy storage modules that periodically perform internal balancing.

[0098] According to some embodiments of the present application, optionally, please continue to refer to Figure 2 , Figure 2 The structure of the energy storage system provided by another embodiment of the present application is shown, only the parts related to the present embodiment are shown for the convenience of description, and the details are as follows:

[0099] The energy storage module 11 includes a plurality of energy storage units 111, and each energy storage unit 111 includes at least one battery; the battery management module 13 includes a battery control unit 132 and a plurality of battery detection units 131; the plurality of battery detection units 131 are connected to the plurality of energy storage units 111 in one-to-one correspondence.

[0100] The battery control unit 132 is connected to the plurality of battery detection units 131 and the conversion module 12, and is configured to trigger the battery detection unit 131 to suspend or resume the balancing process on the corresponding energy storage unit 111 under the excitation of the second voltage.

[0101] The battery management module 13 includes a battery control unit 132 and a plurality of battery detection units 131, the battery detection unit 131 is used for balancing the battery, and the battery detection unit 131 is directly powered by the battery through a sampling line, is not powered by the conversion module 12, and the battery detection unit 131 and the battery control unit 132 can communicate and exchange information through a daisy chain or a controller area network (CAN) bus. The battery control unit 132 is powered by the conversion module 12. Under normal circumstances, the balancing in the energy storage module 11 can be judged by the battery detection unit 131, and only when the voltage difference between the energy storage units 111 is too large, that is, there is an energy storage unit 111 with excessively high voltage, the battery control unit 132 can send a command to the corresponding battery detection unit 131 to suspend the balancing of the energy storage unit 111 with lower voltage, and after the energy storage unit 111 with excessively high voltage is balanced, the self-balancing of other energy storage units 111 is started according to the situation.

[0102] By using the above scheme, the battery detection unit 131 is controlled to suspend or resume the balancing process on the corresponding energy storage unit 111, and the balancing control of each energy storage unit 111 in the energy storage module 11 is realized.

[0103] According to some embodiments of the present application, the plurality of battery detection units include a first target battery detection unit, and the plurality of energy storage units include a first target energy storage unit; the battery control unit 132 is specifically configured to send first control information to the first target battery detection unit 131 under the excitation of the second voltage; and the first control information is used to trigger the first target detection unit to suspend the balancing process on the plurality of batteries in the first target energy storage unit 111.

[0104] The real-time first voltage of the first target energy storage unit 111 and the voltage difference of the real-time first voltage of the same energy storage module 11 are greater than a threshold value; and the first target battery detection unit 131 is a battery detection unit 131 connected to the first target energy storage unit 111.

[0105] It should be noted that only by comparing the real-time first voltage of each energy storage unit 111 with the voltage difference of the energy storage unit 111 with the largest real-time first voltage in the same energy storage module 11 whether it is greater than the threshold value, the first target energy storage unit 111 which needs to be suspended equalization can be obtained, the method has high reliability, and the algorithm is simple.

[0106] By adopting the above scheme, the energy storage units 111 with the voltage difference between the real-time first voltage and the largest real-time first voltage in the same energy storage module 11 greater than the threshold value are suspended equalization processing, so that the energy storage units 111 with smaller first voltage in the energy storage module 11 are suspended equalization processing, and the energy storage units 111 with larger first voltage in the energy storage module 11 maintain equalization processing. After the battery equalization, the first voltage of the energy storage unit 111 will be reduced, which improves the consistency of each energy storage unit 111 and the consistency of each battery in each energy storage unit 111.

[0107] In some embodiments, the plurality of battery detection units includes a second target battery detection unit, and the plurality of energy storage units includes a second target energy storage unit; the battery control unit 132 is further configured to send second control information to the second target battery detection unit 131 under the excitation of the second voltage, and the second control information is used to trigger the second target detection unit to resume the equalization processing of the plurality of batteries in the second target energy storage unit 111.

[0108] Among them, the second target energy storage unit 111 is the energy storage unit 111 which is suspended equalization processing and whose voltage difference between the real-time first voltage and the largest real-time first voltage in the same energy storage module 11 is less than or equal to the threshold value; the second target battery detection unit 131 is the battery detection unit 131 connected with the second target energy storage unit 111.

[0109] It should be noted that only by comparing the real-time first voltage of each energy storage unit 111 with the voltage difference of the energy storage unit 111 with the largest real-time first voltage in the same energy storage module 11 whether it is greater than the threshold value, the first target energy storage unit 111 which needs to be suspended equalization can be obtained, the method has high reliability, and the algorithm is simple.

[0110] By adopting the above scheme, the energy storage units 111 with the voltage difference between the real-time first voltage and the largest real-time first voltage in the same energy storage module 11 greater than the threshold value are suspended equalization processing, so that the energy storage units 111 with smaller first voltage in the energy storage module 11 are suspended equalization processing, and the energy storage units 111 with larger first voltage in the energy storage module 11 maintain equalization processing. After the battery equalization, the first voltage of the energy storage unit 111 will be reduced, which improves the consistency of each energy storage unit 111 and the consistency of each battery in each energy storage unit 111.

[0111] According to some embodiments of the present application, please continue to refer to Figure 3 , Figure 3 The structure diagram of the direct current power supply system provided by another embodiment of the present application is shown, only the parts related to the present embodiment are shown for the convenience of description, and the details are as follows:

[0112] In addition to all the components and assemblies of the direct current power supply system as shown in Figure 1 , the direct current power supply system further comprises a direct current bus.

[0113] The at least one energy storage module 11 is connected to the direct current bus in an on-off manner.

[0114] The conversion module 12 is connected to the direct current bus and the at least one energy storage module 11, and is specifically configured to periodically wake up for a preset time length, and in the case of waking up, convert the first voltage of one of the energy storage modules 11 or the voltage of the direct current bus into a second voltage.

[0115] It should be noted that since the at least one energy storage module 11 is connected to the direct current bus in an on-off manner, and the conversion module 12 can take power from the direct current bus, the balance consistency between the energy storage modules 11 is improved.

[0116] By adopting the above scheme, the conversion module 12 takes the first voltage of one of the energy storage modules 11 or the voltage of the direct current bus as the power supply, improving the flexibility of power supply selection.

[0117] According to some embodiments of the present application, please continue to refer to Figure 4 , Figure 4 The structure diagram of the direct current power supply system provided by another embodiment of the present application is shown, only the parts related to the present embodiment are shown for the convenience of description, and the details are as follows:

[0118] In addition to all the components and assemblies of the direct current power supply system as shown in Figure 3 , the direct current power supply system further comprises a first switch K1 and a second switch K2.

[0119] The first end of each first switch K1 is connected to each energy storage module 11 one by one.

[0120] The second end of each first switch K1 is connected to the first end of each second switch K2 one by one.

[0121] The second end of each second switch K2 is connected to the direct current bus.

[0122] It should be noted that the first switch K1 can be a manually controllable switching device. The second switch K2 can be a high-voltage contactor or a relay. The relay can be an electromagnetic relay, an inductive relay, an electric relay, an electronic relay, etc., which is not limited here. The high-voltage contactor can be an electromagnetic contactor, a permanent magnet contactor, etc., which is not limited here.

[0123] By adopting the above scheme, it is realized that each energy storage module 11 can be connected to the DC bus in an on-off manner.

[0124] According to some embodiments of the present application, optionally, please continue to refer to Figure 5 , Figure 5 The structure of the DC power supply system provided by another embodiment of the present application is shown. For the sake of convenience, only the parts related to the present embodiment are shown, and the details are as follows:

[0125] In addition to all the components and assemblies of the DC power supply system as shown in Figure 3 , the power distribution module 14 is further included.

[0126] The power distribution module 14 is connected to the conversion module 12, the DC bus and at least one energy storage module 11, respectively, and is configured to transmit the voltage of the DC bus to the conversion module 12 in response to a first condition.

[0127] The first condition includes that the difference between the voltage of each energy storage module 11 and the voltage of the DC bus is less than or equal to a first preset voltage.

[0128] It can be understood that after each energy storage module 11 is connected to the DC bus, each energy storage module 11 performs self-discharge and realizes voltage balancing. At this time, taking power from the DC bus is beneficial to the balanced discharge of each energy storage module 11.

[0129] By adopting the above scheme, it is realized that the power is preferentially taken from the DC bus.

[0130] According to some embodiments of the present application, optionally, please continue to refer to Figure 5 , the power distribution module 14 is further configured to transmit the first voltage of the energy storage module 11 with the largest voltage value to the conversion module 12 in response to a second condition.

[0131] The second condition includes that the difference between the first voltage of at least one energy storage module 11 and the voltage of the DC bus is greater than the first preset voltage.

[0132] In the case that the voltage of the DC bus is insufficient or cannot be supplied for other reasons, each energy storage module 11 can adopt a "rotating power supply" strategy through the power distribution module 14. In the case that the current energy storage module 11 is discharged to a certain value, other energy storage modules 11 will be replaced according to the principle of "who is high, who is taken". In this way, all energy storage modules 11 are consumed evenly, and it is not easy for one energy storage module 11 to supply power continuously, resulting in low power. This method ensures the voltage balance of the energy storage module 11, improves the system utilization and overall reliability.

[0133] By adopting the above scheme, when the voltage of the DC bus is insufficient, the energy storage module 11 with the highest voltage is selected to supply power, thereby achieving voltage balance of each energy storage module 11, improving system utilization and reliability.

[0134] According to some embodiments of the present application, please continue to refer to Figure 6 , Figure 6 The structure of the power distribution module 14 in the energy storage system provided by another embodiment of the present application is shown. For ease of illustration, only parts related to the present embodiment are shown, and the details are as follows:

[0135] The power distribution module 14 includes a first diode D1, a plurality of second diodes D2 and a plurality of third diodes D3.

[0136] The positive electrode of the first diode D1 constitutes the voltage input end of the DC bus of the power distribution module 14, and is connected to the DC bus to access the voltage of the DC bus.

[0137] Each second diode D2 constitutes a first voltage input end of each energy storage module 11 of the power distribution module 14, and is connected to each energy storage module 11 one by one to access the first voltage of each energy storage module 11.

[0138] The negative electrode of each second diode D2 is connected to the positive electrode of each third diode D3 one by one.

[0139] The negative electrode of each third diode D3 is connected to the negative electrode of the first diode D1 and constitutes a second voltage output end of the power distribution module 14. The second voltage output end is connected to each battery management module 13 to output the second voltage.

[0140] It can be understood that the voltage of the DC bus is stepped down through the first diode D1, and the first voltage of the energy storage module 11 is stepped down through the second diode D2 and the third diode D3.

[0141] When each first switch K1 and each second switch K2 are closed, and after each energy storage module 11 is self-discharged to reach voltage balance, the voltage of the DC bus is equal to the first voltage of each energy storage module 11, and since the voltage of the DC bus is only stepped down by one diode and the first voltage of each energy storage module 11 is stepped down by two diodes, each second diode D2 and each third diode D3 are cut off, the branch of each second diode D2 and each third diode D3 is disconnected, and the power distribution module 14 takes power from the voltage of the DC bus.

[0142] When each second switch K2 is disconnected or each first switch K1 is disconnected, there is no voltage on the DC bus, the first diode D1 is cut off, the first voltage of the largest energy storage module 11 is converted into the second voltage, that is, power is taken from the energy storage module 11 corresponding to the largest first voltage, and after the energy storage module 11 is discharged for a period of time, the voltage of the energy storage module 11 is lower than the voltage of another energy storage module 11, so that power is taken from the other energy storage module 11, and the above process is repeated to realize balanced discharge of each energy storage module 11.

[0143] By adopting the above scheme, the power is preferentially taken from the DC bus in the form of circuit topology, and when the voltage of the DC bus is insufficient, power is taken from the energy storage module 11 with the highest voltage, and the implementation method does not require software configuration, has high reliability and low cost.

[0144] According to some embodiments of the present application, optionally, please continue to refer to Figure 7 , Figure 7 A structure diagram of a DC power supply system provided by another embodiment of the present application is shown, only parts related to the present embodiment are shown for the convenience of description, and the details are as follows:

[0145] In addition to all the components and assemblies of the DC power supply system as shown in Figure 1 , the DC power supply system further comprises a battery management system 15.

[0146] The battery management system 15 is connected with each energy storage module 11 and the conversion module 12, respectively, and the battery management system 15 is configured to control the equalization of each energy storage module 11 according to the second voltage.

[0147] It can be understood that the battery management system 15 detects the first voltage of each energy storage module 11, and controls the equalization of each energy storage module 11 according to the first voltage of each energy storage module 11 under the excitation of the second voltage.

[0148] By adopting the above scheme, the equalization between each energy storage module 11 is realized, and when debugging and putting into operation, the difference between each energy storage module 11 is small, which further improves the reliability and safety of the energy storage system.

[0149] According to some embodiments of the present application, please continue to refer to Figure 8 , Figure 8 A structure diagram of a direct current power supply system according to another embodiment of the present application is shown, only parts related to the present embodiment are shown for the convenience of description, and the details are as follows:

[0150] In addition to all components and assemblies of the direct current power supply system as shown in Figure 1 , the direct current power supply system further comprises an external power supply 16.

[0151] The external power supply 16 is configured to provide alternating current.

[0152] The conversion module 12 is connected with at least one energy storage module 11 and the external power supply 16.

[0153] The conversion module 12 is specifically configured to periodically wake up for a preset time length, and convert the first voltage of one of the energy storage modules 11 or the alternating current into the second voltage in the case of waking up.

[0154] It should be noted that the external power supply 16 can be an uninterruptible power supply (UPS) or a generator.

[0155] By using the above scheme, the external power supply 16 is used as a system power supply, and the flexibility of power supply selection is improved.

[0156] According to some embodiments of the present application, a control method applied to the energy storage system as shown in Figure 1 is further provided, comprising:

[0157] The conversion module 12 periodically wakes up.

[0158] In the case of waking up, the conversion module 12 outputs the second voltage based on the first voltage of at least one energy storage module 11 to supply power to each battery management module 13.

[0159] The battery management module 13 is configured to perform balancing control processing on a plurality of batteries in the one-to-one corresponding at least one energy storage module 11 under the excitation of the second voltage.

[0160] It should be noted that by setting the conversion module 12 for the at least one energy storage module 11, the conversion module 12 is powered by using the first voltage of the energy storage module 11 itself, and is connected to the control system (the battery management module 13) of each energy storage module 11 to supply power to each battery management module 13. The conversion module 12 wakes up for a second time length (T2) every second time length (T2), and each battery management module 13 starts to work during the wake-up period. By analyzing and calculating the information state of each battery in the energy storage module 11, it is determined whether to start or stop internal balancing, and the corresponding instructions are issued. By this way of periodic sleep and start and self-power, the possibility of too large battery difference can be reduced, thereby reducing the possibility of on-site power compensation, improving the flexibility of operation, and reducing the debugging workload; at the same time, the equalization overcurrent capacity can be reduced from more than 3A to less than or equal to 200mA, and the line cross section specification can be greatly reduced.

[0161] By using the above scheme, the internal balancing of the energy storage module 11 (battery cluster) is periodically performed before the energy storage module 11 is integrated (such as during transportation), which improves the consistency of each battery when debugging and putting into operation, simplifies the debugging equipment, and does not need additional power compensation. A fuse can be used without using a high-temperature wire to prevent the wire from melting and sparking, so the cost is low and the reliability is high. By using the above scheme, the external power supply 16 is used as the system power supply, and the flexibility of power supply selection is improved.

[0162] According to some embodiments of the present application, the energy storage system further includes a direct current bus, and the at least one energy storage module 11 is connected to the direct current bus in an on-off manner. Figure 2

[0163] In the case of wake-up, the conversion module 12 outputs a second voltage based on the first voltage of the at least one energy storage module 11 to supply power to each battery management module 13, specifically:

[0164] In the case of wake-up, the conversion module 12 converts the first voltage of one of the energy storage modules 11 or the voltage of the direct current bus into a second voltage.

[0165] It should be noted that since the at least one energy storage module 11 is connected to the direct current bus in an on-off manner, and the conversion module 12 can take power from the direct current bus, the consistency of the balancing between each energy storage module 11 is improved.

[0166] By using the above scheme, the conversion module 12 uses the first voltage of one of the energy storage modules 11 or the voltage of the direct current bus as the power supply, which improves the flexibility of power supply selection.

[0167] ​It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An energy storage system, characterized by, The energy storage system comprises at least one energy storage module, a conversion module and at least one battery management module; the energy storage module comprises a plurality of batteries; The conversion module is connected with at least one energy storage module, is configured to periodically wake up, and outputs a second voltage based on a first voltage of the at least one energy storage module in the case of waking up; The at least one battery management module is connected with the conversion module and one-to-one connected with the at least one energy storage module, and the at least one battery management module is configured to perform balancing control processing on a plurality of batteries in the one-to-one corresponding at least one energy storage module under the excitation of the second voltage.

2. The energy storage system of claim 1, wherein, The conversion module is multiple, the battery management module is multiple, and the energy storage module is multiple; Each conversion module is connected with at least one energy storage module, is configured to periodically wake up, and outputs a second voltage based on a first voltage of the at least one energy storage module in the case of waking up; Each battery management module is connected with a conversion module and one-to-one connected with each energy storage module, and each battery management module is configured to perform balancing control processing on a plurality of batteries in the one-to-one corresponding multiple energy storage modules under the excitation of the second voltage.

3. The energy storage system of claim 1, wherein, The energy storage module comprises a plurality of energy storage units, and the energy storage unit comprises at least one battery; the battery management module comprises a battery control unit and a plurality of battery detection units; a plurality of battery detection units are one-to-one connected with a plurality of energy storage units; The battery control unit is connected with a plurality of battery detection units and the conversion module, and is configured to trigger the battery detection unit to suspend or resume the balancing processing on the corresponding energy storage unit under the excitation of the second voltage.

4. The energy storage system of claim 3, wherein, The plurality of battery detection units comprise a first target battery detection unit, and the plurality of energy storage units comprise a first target energy storage unit; the battery control unit is specifically configured to send first control information to the first target battery detection unit under the excitation of the second voltage; the first control information is used to trigger the first target detection unit to suspend the balancing processing on a plurality of batteries in the first target energy storage unit; The real-time first voltage of the first target energy storage unit is greater than the threshold value from the voltage of the energy storage unit with the maximum real-time first voltage in the same energy storage module; the first target battery detection unit is a battery detection unit connected with the first target energy storage unit.

5. The energy storage system of claim 4, wherein, The plurality of battery detection units comprise a second target battery detection unit, and the plurality of energy storage units comprise a second target energy storage unit; the battery control unit is further configured to send second control information to the second target battery detection unit under the excitation of the second voltage, and the second control information is used to trigger the second target detection unit to resume the balancing processing on a plurality of batteries in the second target energy storage unit; The second target energy storage unit is an energy storage unit that is suspended from the equalization process, and the voltage difference between the real-time first voltage and the voltage of the energy storage unit with the largest real-time first voltage in the same energy storage module is less than or equal to a threshold value; and the second target battery detection unit is the battery detection unit connected to the second target energy storage unit.

6. The energy storage system of claim 1, wherein, Further comprising a direct current bus; At least one of the energy storage modules is connected to the direct current bus in an on-off manner; The conversion module is connected to the direct current bus and at least one of the energy storage modules, and is specifically configured to periodically wake up for a preset time period, and in the case of waking up, convert the first voltage of one of the energy storage modules or the voltage of the direct current bus into the second voltage.

7. The energy storage system of claim 6, wherein, Further comprising a power distribution module; The power distribution module is connected to the conversion module, the direct current bus and at least one of the energy storage modules, and is configured to transmit the voltage of the direct current bus to the conversion module in response to a first condition. The first condition includes that the voltage difference between the voltage of each of the energy storage modules and the voltage of the direct current bus is less than or equal to a first preset voltage.

8. The energy storage system of claim 7, wherein, The power distribution module is further configured to transmit the first voltage of the energy storage module with the largest voltage to the conversion module in response to a second condition. The second condition includes that the voltage difference between the first voltage of at least one of the energy storage modules and the voltage of the direct current bus is greater than the first preset voltage.

9. The energy storage system of claim 8, wherein, The power distribution module includes a first diode, a plurality of second diodes and a plurality of third diodes; The positive electrode of the first diode constitutes the voltage input end of the direct current bus of the power distribution module, and is connected to the direct current bus to access the voltage of the direct current bus; Each second diode constitutes a first voltage input end of each energy storage module of the power distribution module, and is connected to each of the energy storage modules in a one-to-one correspondence to access the first voltage of each of the energy storage modules; The negative electrode of each second diode is connected to the positive electrode of each third diode in a one-to-one correspondence; The negative electrode of each third diode is connected to the negative electrode of the first diode and constitutes a second voltage output end of the power distribution module, and the second voltage output end is connected to each battery management module to output the second voltage.

10. An energy storage system as claimed in any one of claims 1 to 9, wherein, Further comprising a first switch and a second switch; The first end of each first switch is connected to each energy storage module in a one-to-one correspondence; The second end of each first switch is connected to the first end of each second switch in a one-to-one correspondence; The second end of each second switch is connected to the direct current bus.

11. An energy storage system as claimed in any one of claims 1 to 9, wherein, Further comprising: A battery management system connected to each energy storage module and the conversion module, and configured to control the equalization of each energy storage module according to the second voltage.

12. An energy storage system as claimed in any one of claims 1 to 9, wherein, Further comprising: An external power source for providing alternating current; The conversion module is connected to at least one of the energy storage modules and the external power source; The conversion module is specifically configured to periodically wake up for a preset time period, and in the case of waking up, convert the first voltage of one of the energy storage modules or the alternating current into the second voltage.

13. An energy storage station, characterized by The energy storage station comprises an energy storage system as claimed in any one of claims 1 to 12.

14. A control method applied to the energy storage system according to any one of claims 1 to 12, characterized in that, Comprise: The conversion module periodically wakes up by itself; In the case of waking up, the conversion module outputs a second voltage based on a first voltage of at least one energy storage module to supply power to each battery management module; The battery management module is configured to perform balancing control processing on a plurality of batteries in the at least one energy storage module corresponding to the battery management module under the excitation of the second voltage.

15. The control method according to claim 14, characterized by, The energy storage system further comprises a direct-current bus, and at least one energy storage module is connected to the direct-current bus in an on-off manner; The conversion module outputs a second voltage based on a first voltage of at least one energy storage module to supply power to each battery management module in the case of waking up, specifically: In the case of waking up, the conversion module converts the first voltage of one of the energy storage modules or the voltage of the direct-current bus into the second voltage.

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