An equalization control device, equalization control method, and related system

Abstract

The application discloses a kind of equalization control device, equalization control method and related system, wherein, equalization control device includes power interface, first series interface, first equalization interface and control module;Control module obtains the state parameters of multiple series battery packs, according to the state parameters of multiple series battery packs, determine whether multiple series battery packs need equalization, and when multiple series battery packs do not need equalization, control first series interface is connected with power interface, so that energy storage converter (PCS) is connected with multiple series battery packs in series, when at least one battery pack needs equalization, control corresponding first equalization interface is connected with power interface, so that energy storage converter is only connected with the battery pack that needs equalization, so that larger charge-discharge power can be provided by energy storage converter, and then larger charge-discharge equalization current can be provided to the battery pack that needs equalization, and then the equalization efficiency of energy storage system can be improved, the equalization period is shortened, and the equalization cost is reduced.

Description

TECHNICAL FIELD

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

[0002] An energy storage system is a battery cluster composed of multiple battery packs in series. Due to the influence of production process and storage time and other factors, there will be a certain difference in the voltage or SOC (State Of Charge) of different battery packs. The greater the voltage difference or SOC difference of different battery packs, the greater the impact on the available energy storage capacity and performance of the energy storage system. Therefore, when the voltage difference or SOC difference of different battery packs is large, it is necessary to balance each battery pack in the energy storage system. However, the current balancing of the energy storage system has a lot of room for improvement in terms of balancing efficiency, balancing operation convenience and balancing device cost. SUMMARY

[0003] The present application discloses a balancing control device, a balancing control method and related systems to improve the balancing rate of the energy storage system, reduce the balancing cost and improve the operation convenience.

[0004] In a first aspect, the present application discloses a balancing control device applied to an energy storage system, wherein the energy storage system comprises multiple battery packs in series, and the balancing control device comprises: a power interface connected with an energy storage converter; a first series interface connected with the multiple battery packs in series; at least one first balancing interface, one first balancing interface being connected with one battery pack, and multiple first balancing interfaces being connected with multiple battery packs respectively; and a control module configured to acquire parameters of the multiple battery packs, determine whether the multiple battery packs need balancing according to the parameters of the multiple battery packs, control the first series interface to be connected with the power interface when none of the multiple battery packs need balancing, and send charging and discharging parameters of the multiple battery packs to the energy storage converter, so that the energy storage converter charges and discharges the multiple battery packs; control the first balancing interface corresponding to at least one battery pack needing balancing to be connected with the power interface when at least one battery pack needs balancing; and send charging and discharging parameters of the battery pack needing balancing to the energy storage converter, so that the energy storage converter charges and discharges the battery pack needing balancing.

[0005] In some optional examples, the equalization control device further comprises a switching switch; a first end of the switching switch is connected with the power interface, a second end of the switching switch is connected with the first series interface, and a third end of the switching switch is connected with the at least one first equalization interface; the control module is connected with a control end of the switching switch; the control module is further configured to control the first end of the switching switch to be connected with the second end when none of the plurality of battery packs needs equalization, and control the first end of the switching switch to be connected with the third end when at least one of the battery packs needs equalization.

[0006] In some optional examples, the equalization control device further comprises a plurality of equalization switches; a first end of each of the equalization switches is connected with the third end of the switching switch, and a second end of each of the equalization switches is connected with the corresponding first equalization interface; the control module is connected with a control end of each of the equalization switches, and the control module is further configured to control the first end of the equalization switch corresponding to the at least one battery pack needing equalization to be connected with the second end of the equalization switch when the at least one battery pack needs equalization.

[0007] In some optional examples, the equalization control device further comprises a first communication interface; the first communication interface is connected in communication with the plurality of battery packs, and the first communication interface is further connected with the control module; the first communication interface is configured to receive parameters sent by the plurality of battery packs and transmit the parameters to the control module.

[0008] In some optional examples, the control module is further configured to send a connection instruction and a disconnection instruction to the energy storage converter; the connection instruction is configured to make the energy storage converter connected with the power interface, and the disconnection instruction is configured to make the energy storage converter disconnected with the power interface.

[0009] In some optional examples, the equalization control device further comprises a second communication interface; the second communication interface is configured to be connected in communication with the energy storage converter; the control module is further connected with the second communication interface, and the control module is further configured to send the connection instruction, the disconnection instruction, and the charge-discharge parameters of the battery packs to the energy storage converter through the second communication interface.

[0010] In some optional examples, the equalization control device further comprises an operation panel; the operation panel is connected with the control module, and the control module is further configured to send an equalization prompt information through the operation panel to prompt a user that at least one of the battery packs in the energy storage system needs equalization, and receive an equalization instruction input by the user through the operation panel to control the corresponding at least one first equalization interface to be connected with the power interface according to the equalization instruction.

[0011] In some optional examples, the battery pack comprises a second series interface and a second equalization interface, the second series interface is connected in parallel with the second equalization interface, the second series interface is used to be connected with the first series interface or a second series interface of another battery pack, and the second equalization interface is used to be connected with the first equalization interface.

[0012] In a second aspect, the application discloses an equalization control system applied to an energy storage system, comprising an energy storage converter and an energy storage management unit, and the energy storage management unit comprises the equalization control device according to any one of the above.

[0013] In some optional examples, the working voltage range of the energy storage converter covers the voltage range of one or more series battery packs in the energy storage system, and the energy storage converter can charge and discharge the one or more series battery packs according to instructions.

[0014] In a third aspect, the application discloses an energy storage system, comprising a plurality of series battery packs and the equalization control system according to the above.

[0015] In a fourth aspect, the application discloses an equalization control method applied to the energy storage system according to the above, and the equalization control method comprises the following steps: obtaining parameters of the plurality of battery packs; determining whether the plurality of battery packs need equalization according to the parameters of the plurality of battery packs; when none of the plurality of battery packs need equalization, connecting the first series interface with the power interface, and sending charge and discharge parameters of the plurality of battery packs to the energy storage converter, so that the energy storage converter charges and discharges the plurality of battery packs; when at least one of the battery packs need equalization, connecting the first equalization interface corresponding to the battery pack with the power interface, and sending charge and discharge parameters of the battery pack needing equalization to the energy storage converter, so that the energy storage converter charges and discharges the battery pack needing equalization.

[0016] In some optional examples, the step of connecting the first series interface with the power interface comprises the following steps: connecting the first end of the switch with the second end; and the step of connecting the first equalization interface corresponding to the battery pack with the power interface comprises the following step: connecting the first end of the switch with the third end.

[0017] In some optional examples, the step of connecting the first equalization interface corresponding to the battery pack with the power interface further comprises the following step: connecting the first end of the equalization switch corresponding to the battery pack needing equalization with the second end thereof.

[0018] In some optional examples, before the control of the connection of the first series connection interface with the power supply interface, or before the control of the connection of the first balancing interface corresponding thereto with the power supply interface, the method further comprises: sending a disconnection instruction to the energy storage converter to control the disconnection of the energy storage converter from the power supply interface; after the control of the connection of the first series connection interface with the power supply interface, or after the control of the connection of the first balancing interface corresponding thereto with the power supply interface, the method further comprises: sending a connection instruction to the energy storage converter to control the connection of the energy storage converter with the power supply interface.

[0019] In some optional examples, after the control of the connection of the first balancing interface corresponding thereto with the power supply interface, the method further comprises: setting a target state parameter according to the stored state parameters of the plurality of battery packs; comparing the state parameter of the battery pack requiring balancing with the target state parameter; and controlling the charging or discharging of the battery pack according to the comparison result.

[0020] In some optional examples, during the balancing of any battery pack, the balancing control method further comprises: periodically collecting the state parameter of the battery pack; comparing the state parameter with the target state parameter; and controlling the battery pack to stop charging or discharging if the difference between the state parameter and the target state parameter is less than a preset value.

[0021] The balancing control device, the balancing control method and the related system disclosed by the application, the energy storage system comprises a plurality of battery packs connected in series, the balancing control device comprises a power supply interface, a first series connection interface, a first balancing interface and a control module, the control module acquires state parameters of the plurality of battery packs, determines whether the plurality of battery packs require balancing according to the state parameters of the plurality of battery packs, and when none of the plurality of battery packs requires balancing, controls the first series connection interface to be connected with the power supply interface and sends charging and discharging parameters of the plurality of battery packs to an energy storage converter, so that the energy storage converter charges and discharges the plurality of battery packs; on the one hand, when at least one battery pack requires balancing, the control module controls the first balancing interface corresponding thereto to be connected with the power supply interface and sends charging and discharging parameters of the battery pack requiring balancing to the energy storage converter, so that the energy storage converter charges and discharges the battery pack requiring balancing, thereby the energy storage converter can provide larger charging and discharging power, and can further provide larger charging and discharging balancing current to the battery pack requiring balancing, thereby the balancing efficiency of the energy storage system can be improved and the balancing period of the energy storage system can be shortened; on the one hand, the balancing is realized by using the existing energy storage converter of the energy storage system without additional balancing equipment, thereby the balancing cost of the energy storage system is reduced. Furthermore, in the application, the balancing of the energy storage system can be conveniently and quickly realized by controlling the connection of the power supply interface with the first balancing interface, the balancing of the energy storage system can be automatically completed without manual intervention, and the balancing convenience of the energy storage system is greatly improved. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the background art, the accompanying drawings used in the embodiments of the present invention or the background art will be described below.

[0023] Figure 1 This is a schematic diagram illustrating the connection relationship between an equalization control device with a first equalization interface, an energy storage converter, and a battery pack, as disclosed in an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram showing the connection relationship between an equalization control device with multiple first equalization interfaces, an energy storage converter, and a battery pack, as disclosed in an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of another equalization control device with a switching switch disclosed in an embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of another equalization control device with a switching switch and an equalization switch disclosed in an embodiment of the present invention.

[0027] Figure 5 This is a schematic diagram illustrating the connection relationship between another equalization control device with a first communication interface, an energy storage converter, and a battery pack, as disclosed in an embodiment of the present invention.

[0028] Figure 6 This is a schematic diagram illustrating the connection relationship between an equalization control device with a second communication interface and an energy storage converter, as disclosed in another embodiment of the present invention.

[0029] Figure 7 This is a schematic diagram illustrating the connection relationship between an equalization control device with an operation panel and an energy storage converter, as disclosed in another embodiment of the present invention.

[0030] Figure 8 This is a schematic diagram of the structure of a battery pack disclosed in an embodiment of the present invention.

[0031] Figure 9 This is a schematic diagram illustrating the connection relationship between an energy storage converter, a balancing control device, and a battery pack, as disclosed in an embodiment of the present invention.

[0032] Figure 10 This is a schematic diagram showing the connection relationship between another equalization control device disclosed in an embodiment of the present invention and a battery pack and an energy storage converter having a second equalization interface.

[0033] Figure 11 This is a flowchart of an equalization control method disclosed in an embodiment of the present invention.

[0034] Figure 12A flowchart of another equalization control method disclosed in embodiments of the present application. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0036] A battery pack is usually composed of a plurality of battery cells connected in series, which can be lithium iron phosphate battery cells or sodium battery cells, etc. Under the restriction of the weight of the battery pack and the management chip, etc., the voltage of a single battery pack is generally not too high, such as generally not exceeding 120V. If higher output power and efficiency are desired, the voltage of the energy storage system including a plurality of series-connected battery packs needs to be increased, and the current of the energy storage system needs to be reduced.

[0037] Since the battery packs are produced, stored and transported separately, the voltages or SOC of different battery packs will be different under the influence of factors such as production process, storage time and transportation time. Based on this, during the assembly of the energy storage system, the battery packs in the energy storage system need to be equalized to reduce the voltage difference or SOC difference of the battery packs in the energy storage system.

[0038] In addition, since the discharge parameters of different battery packs will be different, the voltages or SOC of different battery packs will also be different after the energy storage system has been working for a period of time. Based on this, during the operation of the energy storage system, the battery packs in the energy storage system also need to be equalized.

[0039] Thirdly, if a battery pack in the energy storage system fails, the voltage or SOC of the repaired or replaced battery pack will also be different from those of the other battery packs after the battery pack is repaired or replaced. Based on this, during the repair of the energy storage system, the battery packs in the energy storage system also need to be equalized.

[0040] Although it is possible to use a special device to fully charge or empty each battery pack in the energy storage system in series during the assembly or repair of the energy storage system, it is not possible to equalize the battery packs in the energy storage system during the operation of the energy storage system. Moreover, using this method for equalization will result in low equalization efficiency, long equalization period and high equalization cost.

[0041] Although the energy of the battery pack with high voltage or high SOC can be transferred to the battery pack with low voltage or low SOC through the energy storage inductor during the working process of the energy storage system, the balancing of each battery pack in the energy storage system can be achieved. However, during the assembly or maintenance of the energy storage system, the balancing of each battery pack in the energy storage system cannot be achieved in this way, or the balancing power of this way is small, the balancing efficiency is low, and the demand of the assembly or maintenance of the energy storage system cannot be met.

[0042] Based on this, the application discloses a balancing control device of an energy storage system, which is used for balancing the energy storage system during the assembly, working or maintenance of the energy storage system. When the battery pack in the energy storage system needs to be balanced, the balancing control device controls the battery pack needing to be balanced to be connected with a power conversion system (PCS). When no battery pack in the energy storage system needs to be balanced, the balancing control device controls all the battery packs in the energy storage system to be connected in series and connected with the power conversion system. Thus, the power conversion system used for supplying power to the energy storage system during the working process of the energy storage system can be reused as a balancing power supply used for supplying power to the energy storage system during the balancing process of the energy storage system. Then, the balancing efficiency of the energy storage system can be improved and the balancing cost can be reduced by using the power conversion system with large power. Since the balancing device can automatically complete the balancing task without manual intervention, the balancing maintenance of the energy storage system is very simple.

[0043] As an optional implementation of the disclosure, the application discloses a balancing control device applied to an energy storage system, which can balance the energy storage system during the assembly, working or maintenance of the energy storage system.

[0044] As shown in Figure 1 The energy storage system 10 includes a plurality of battery packs 100 connected in series, and the balancing control device 20 includes a power supply interface 201, a first series connection interface 202, at least one first balancing interface 203 and a control module 204. It can be understood that Figure 1 The battery packs 100 of the energy storage system 10 can be 2, 4, 5 or more, which are only taken as an example of 3 battery packs 100.

[0045] The power supply interface 201 is used for being connected with the power conversion system 30. The power supply interface 201 can be a PCS interface, the power conversion system 30 can be connected with a power grid or a photovoltaic power station, and is used for controlling the energy storage system 10 to charge and discharge. For example, when the power of the plurality of battery packs 100 is almost consumed, the plurality of battery packs 100 can be charged by the power conversion system 30. Or, when the power of the plurality of battery packs 100 is overfull, the plurality of battery packs 100 can also be discharged by the power conversion system 30.

[0046] The first series interface 202 is used to connect with the plurality of battery packs 100 in series. For example, each battery pack 100 includes a positive electrode and a negative electrode, and in the plurality of battery packs 100 in series, the positive electrode of the first battery pack 100 is connected with the negative electrode of the second battery pack 100, the positive electrode of the second battery pack 100 is connected with the negative electrode of the third battery pack 100, and so on, and then the negative electrode of the first battery pack 100 is connected with the second negative terminal of the first series interface 202, and the positive electrode of the last battery pack 100 is connected with the second positive terminal of the first series interface 202. Among them, the different battery packs 100 and the battery packs 100 and the first series interface 202 can be connected in series through wires and the like.

[0047] A first equalization interface 203 is used to connect with a battery pack 100, and a plurality of first equalization interfaces 203 are used to connect with a plurality of battery packs 100 respectively. Specifically, the second positive terminal of the first equalization interface 203 is connected with the positive electrode of the battery pack 100, and the second negative terminal of the first equalization interface 203 is connected with the negative electrode of the battery pack 100.

[0048] The control module 204 is used to obtain the parameters of the plurality of battery packs 100 in the energy storage system 10, determine whether the plurality of battery packs 100 need to be equalized according to the parameters of the plurality of battery packs 100, and when the plurality of battery packs 100 do not need to be equalized, control the first series interface 202 to be connected with the power interface 201, and send the charging and discharging parameters of the plurality of battery packs 100 to the energy storage converter 30, so that the energy storage converter 30 charges and discharges the plurality of battery packs 100. When at least one battery pack 100 needs to be equalized, control the corresponding at least one first equalization interface 203 to be connected with the power interface 201; that is, control the at least one first equalization interface 203 connected with the at least one battery pack 100 that needs to be equalized to be connected with the power interface 201, and send the charging and discharging parameters of the battery pack 100 that needs to be equalized to the energy storage converter 30, so that the energy storage converter 30 charges and discharges the battery pack 100 that needs to be equalized.

[0049] The parameters of the battery pack 100 can include one or more of voltage, current, SOC, temperature, and the like. For example, if the parameters of the battery pack 100 include voltage, the battery pack 100 can be subjected to voltage balancing according to the parameters; if the parameters of the battery pack 100 include SOC, the battery pack 100 can be subjected to power balancing according to the parameters; if the parameters of the battery pack 100 include voltage and SOC, the battery pack 100 can be subjected to voltage balancing and power balancing according to the parameters. The charge and discharge parameters of the battery pack 100 include charge and discharge current, charge and discharge voltage, target voltage, target current, and the like of the battery pack 100. After the charge and discharge parameters of the plurality of battery packs 100 or the battery pack 100 that needs to be balanced are sent to the energy storage converter 30, the energy storage converter 30 can be caused to provide charge and discharge currents and the like that match the plurality of battery packs 100 or the battery pack 100 that needs to be balanced.

[0050] During assembly, operation, or maintenance of the energy storage system 10, the control module 204 acquires and stores the voltage and SOC and the like of the plurality of battery packs 100 in the energy storage system 10, and compares the voltage and / or SOC of any two battery packs 100. If the voltage difference and / or the SOC difference of any two battery packs 100 is less than a preset value, it indicates that the plurality of battery packs 100 in the energy storage system 10 do not need to be balanced. At this time, the control module 204 can control the first series interface 202 to be connected to the power interface 201, and send the charge and discharge parameters of the plurality of battery packs 100 to the energy storage converter 30, so that the plurality of battery packs 100 in series in the energy storage system 10 are connected to the energy storage converter 30, and the plurality of battery packs 100 in series are charged or discharged through the energy storage converter 30.

[0051] If the voltage difference and / or the SOC difference of at least two battery packs 100 is greater than or equal to a preset value, such as the voltage difference being greater than or equal to 0.1V*N and / or the SOC difference being greater than or equal to 5%, N being the number of battery packs 100 in the energy storage system, it indicates that the voltage difference and / or the SOC difference of the two battery packs 100 is large, and at least one battery pack 100 needs to be balanced so that the voltage difference and / or the SOC difference of the at least two battery packs 100 is less than a preset value, such as the voltage difference being less than 0.1V*N and / or the SOC difference being less than 5%, wherein the preset value of the voltage difference and the preset value of the SOC difference are not the same. At this time, the control module 204 can control the first balancing interface 203 connected to the battery pack 100 that needs to be balanced to be connected to the power interface 201, and send the charge and discharge parameters of the battery pack 100 that needs to be balanced to the energy storage converter 30, so that the battery pack 100 that needs to be balanced is connected to the energy storage converter 30, and the battery pack 100 that needs to be balanced is charged or discharged through the energy storage converter 30.

[0052] It can be understood that after all the battery packs 100 in the energy storage system 10 are balanced, the voltage difference and / or the SOC difference between any two battery packs 100 are less than the preset value, and the control module 204 can control the first series interface 202 to be connected with the power supply interface 201, so that the energy storage system 10 performs normal charging and discharging work.

[0053] It can also be understood that the control module 204 can set the target voltage and / or the target SOC and the balancing current value of the battery pack 100 to be balanced according to the stored voltage and / or SOC and other parameters of the plurality of battery packs 100, and then compare the voltage of the battery pack 100 to be balanced with the target voltage, and / or compare the SOC of the battery pack 100 to be balanced with the target SOC. If the voltage of the battery pack 100 to be balanced is greater than the target voltage, and / or the SOC of the battery pack 100 to be balanced is greater than the target SOC, the battery pack 100 is controlled to be discharged to achieve the balancing of the battery pack 100. If the voltage of the battery pack 100 to be balanced is less than the target voltage, and / or the SOC of the battery pack 100 to be balanced is less than the target SOC, the battery pack 100 is controlled to be charged to achieve the balancing of the battery pack 100.

[0054] In addition, during the balancing of the battery pack 100, the control module 204 will regularly collect the voltage and SOC and other parameters of the battery pack 100, and compare the collected voltage with the target voltage, and / or compare the collected SOC with the target SOC. If the difference between the collected voltage and the target voltage is less than the preset value, and / or the difference between the collected SOC and the target SOC is also less than the preset value, it means that the balancing of the battery pack 100 is completed, and the control module 204 controls the battery pack 100 to stop charging or discharging, i.e. to stop balancing, by controlling the first series interface 202 to be connected with the power supply interface 201.

[0055] Based on this, the energy storage converter 30 that provides working power for the energy storage system 10 can be multiplexed as a balancing power supply that provides balancing power for the energy storage system 10, so that the charging and discharging power with larger power can be provided through the energy storage converter 30, thereby improving the balancing efficiency of the energy storage system 10, shortening the balancing period of the energy storage system 10, and reducing the balancing cost of the energy storage system 10. In addition, in the present application, by controlling the power supply interface 201 to be connected with the first balancing interface 203, the balancing of the energy storage system 10 can be conveniently and quickly achieved, further improving the balancing efficiency of the energy storage system 10.

[0056] It should be noted that the equalization control device can be integrated in an energy storage management unit (EMU) of the energy storage system, or the equalization control device can reuse the energy storage management unit (EMU) ; the control module 204 can be integrated in an energy controller (EMS) of the energy storage management unit (EMU), and can also reuse the energy controller (EMS).

[0057] In some embodiments of the present application, as shown in Figure 1 When one battery pack 100 needs equalization, the first equalization interface 203 connected with the power interface 201 can be connected with the one battery pack 100 to realize equalization of the one battery pack 100. When multiple battery packs 100 need equalization, the first equalization interface 203 connected with the power interface 201 can be connected with the multiple battery packs 100 in turn to realize equalization of the multiple battery packs 100 in turn.

[0058] Of course, the present application is not limited to this, and in other embodiments, as shown in Figure 2 The equalization control device 20 can include multiple first equalization interfaces 203, and the multiple first equalization interfaces 203 are respectively connected with the multiple battery packs 100. When any battery pack 100 needs equalization, the power interface 201 and the first equalization interface 203 connected with the battery pack 100 can be connected to realize equalization of the battery pack 100.

[0059] In some embodiments of the present application, as shown in Figure 3 The equalization control device 20 further includes a switching switch 205. The first end of the switching switch 205 is connected with the power interface 201, the second end of the switching switch 205 is connected with the first series interface 202, and the third end of the switching switch 205 is connected with at least one first equalization interface 203. The control module 204 is connected with the control end of the switching switch 205, and the control module 204 is further used for connecting the first end and the second end of the switching switch 205 to control the power interface 201 to be connected with the first series interface 202 when multiple battery packs 100 do not need equalization, and connecting the first end and the third end of the switching switch 205 to control the power interface 201 to be connected with the corresponding at least one first equalization interface 203 when at least one battery pack 100 needs equalization.

[0060] The switch 205 has the following characteristics: a first positive terminal a1 and a first negative terminal b1; a second positive terminal a2 and a second negative terminal b2; and a third positive terminal a3 and a third negative terminal b3. The first positive terminal a1 can be connected to either the second positive terminal a2 or the third positive terminal a3, and the first negative terminal b1 can be connected to either the second negative terminal b2 or the third negative terminal b3. Connecting the first terminal to the second terminal means that the first positive terminal a1 is connected to the second positive terminal a2 and the first negative terminal b1 is connected to the second negative terminal b2; connecting the first terminal to the third terminal means that the first positive terminal a1 is connected to the third positive terminal a3 and the first negative terminal b1 is connected to the third negative terminal b3.

[0061] In addition, the second positive terminal a2 of the switch 205 is connected to the first positive terminal of the first serial interface 202, and the second negative terminal b2 of the switch 205 is connected to the first negative terminal of the first serial interface 202; the third positive terminal a3 of the switch 205 is connected to the first positive terminal of the first equalization interface 203, and the second negative terminal b3 of the switch 205 is connected to the first negative terminal of the first equalization interface 203.

[0062] In some embodiments, such as Figure 3 As shown, a switching switch 205 may include a double-pole double-throw switch, which may include a relay 2050. The control module 204 may control the current of the relay 2050 through the drive circuit, thereby controlling the relay 2050 to engage or disengage the double-pole, and thus controlling the double-pole double-throw switch to close or open.

[0063] It is understood that the control module 204 can determine whether the current state of the switch 205 is closed or open based on the drive signal of the drive circuit, and then determine whether to perform equalization based on the state information of the switch 205. Of course, the present invention is not limited to this. In some other embodiments, a switch 205 may also include two single-pole double-throw switches or two MOS switching transistors, etc., which will not be described in detail here.

[0064] For example, when at least one battery pack 100 needs to be balanced, the control module 204 controls the first end of the switch 205 to connect to the third end, so as to control the power interface 201 to connect to at least one corresponding first equalization interface 203. Then, the control module 204 will detect the state of the switch 205. If it is detected that the first end of the switch 205 is connected to the third end, the control module 204 will perform subsequent equalization steps such as setting the target voltage and / or target SOC. If it is not detected that the first end of the switch 205 is connected to the third end, the control module 204 will continue to detect the state of the switch 205 until it is detected that the first end of the switch 205 is connected to the third end, and then proceed to the subsequent equalization steps.

[0065] After the battery packs 100 have been balanced, that is, when all battery packs 100 in the energy storage system 10 do not need to be balanced, the control module 204 controls the first end of the switching switch 205 to connect to the third end, so as to control the power interface 201 to connect to at least one corresponding first balancing interface 203. Then the control module 204 will detect the status of the switching switch 205. If the first end of the switching switch 205 is not detected to be connected to the third end, the control module 204 will continue to detect the status of the switching switch 205 until the first end of the switching switch 205 is detected to be connected to the third end. Then the control module 204 controls the energy storage converter 30 to connect to the power interface 201.

[0066] In some embodiments, such as Figure 3 As shown, if the equalization control device 20 only includes a first equalization interface 203, then the equalization control device 20 only needs to include a switching switch 205. However, in other embodiments, such as... Figure 4 As shown, the equalization control device 20 includes multiple first equalization interfaces 203. The equalization control device 20 may also include multiple equalization switches 206. The first end of the equalization switch 206 is connected to the third end of the switching switch 205. The second ends of the multiple equalization switches 206 are respectively connected to the multiple first equalization interfaces 203. The control module 204 is respectively connected to the control terminals of the multiple equalization switches 206. The control module 204 is also used to control the first end of the corresponding at least one equalization switch 206 to connect to its second end when at least one battery pack 100 needs to be equalized.

[0067] The equalizer switch 206 has a first positive terminal c1 and a first negative terminal d1, and a second positive terminal c2 and a second negative terminal d2. The first and second terminals of the equalizer switch 206 are connected in that the first positive terminal c1 is connected to the second positive terminal c2, and the first negative terminal d1 is connected to the second negative terminal d2.

[0068] In some embodiments, such as Figure 4 As shown, an equalization switch 206 may include a double-pole single-throw switch. Similarly, the double-pole single-throw switch may include a relay 2060. The control module 204 can control the closing and opening of the double pole by controlling the relay 2060. Of course, the invention is not limited to this. In other embodiments, an equalization switch 206 may also include two single-pole single-throw switches or two MOSFETs, etc.

[0069] Of course, the present application is not limited to this, and in other embodiments, the control module 204 can also be a chip or the like, and the power supply interface 201, the first series interface 202 and the at least one first equalization interface 203 are connected to different pins of the chip, and the control module can realize the connection of the power supply interface 201 and the first series interface 202 or the first equalization interface 203 through the internal circuit of the chip, or realize the communication connection with the battery pack 100 and / or the energy storage converter 30 through the internal wireless communication module.

[0070] It should be noted that if the equalization control device 20 only includes one first equalization interface 203, the first equalization interface 203 can be connected to the plurality of battery packs 100 in turn through manual control. If the equalization control device 20 includes a plurality of first equalization interfaces 203, the plurality of first equalization interfaces 203 can be automatically connected to the plurality of battery packs 100 through the control module 204.

[0071] In some embodiments of the present application, as shown in Figure 5 The equalization control device 20 can also include a first communication interface 207, the first communication interface 207 is in communication connection with the plurality of battery packs 100, and the first communication interface 207 is also connected to the control module 204. The first communication interface 207 is used to receive the parameters sent by the plurality of battery packs 100 and transmit the parameters to the control module 204.

[0072] The first communication interface 207 can be in wired communication connection with the battery pack 100 through a communication line, or in wireless communication connection with the battery pack 100 through 4G, Bluetooth, WIFI, etc. In addition, the first communication interface 207 can be a BMS communication interface to communicate with the battery management system BMS in the battery pack 100.

[0073] It can be understood that, Figure 5 It should be noted that, in the drawings and the like, only the equalization control device 20 with one first equalization interface 203 is taken as an example for description, but it is not limited thereto, that is, the equalization control device 20 with a plurality of first equalization interfaces 203 can also have a first communication interface 207 and the like.

[0074] In some embodiments of the present application, the control module 204 is also used to send a connection instruction and a disconnection instruction to the energy storage converter 30; the connection instruction is used to make the energy storage converter 30 in communication with the power supply interface 201, and the disconnection instruction is used to make the energy storage converter 30 disconnected from the power supply interface 201. Of course, the present application is not limited to this, and in other embodiments, the control module 204 can also control the energy storage converter 30 to be in communication or disconnected with the power supply interface 201 by controlling the switch between the energy storage converter 30 and the power supply interface 201, which will not be described herein.

[0075] In some embodiments, as shown inFigure 6 As shown, the equalization control device 20 can further include a second communication interface 208 configured to be communicatively connected with the energy storage converter 30. The second communication interface 208 can be a PCS communication interface. The control module 204 is further connected with the second communication interface 208, and the control module 204 is further configured to send a connection instruction, a disconnection instruction, and a charge-discharge parameter of the battery pack 100 to the energy storage converter 30 through the second communication interface 208.

[0076] For example, if at least one battery pack 100 needs to be equalized, the control module 204 first sends a disconnection instruction to the energy storage converter 30 through the second communication interface 208, so that the energy storage converter 30 is disconnected from the power interface 201. Then, the control module 204 controls the state of the switching switch 205, so that the first equalization interface 203 connected with the battery pack 100 that needs to be equalized is connected with the power interface 201. After that, the control module 204 sends a connection instruction to the energy storage converter 30 through the second communication interface 208, so that the energy storage converter 30 is connected with the battery pack 100 that needs to be equalized.

[0077] After the equalization of the battery pack 100 is completed, the control module 204 sends a disconnection instruction to the energy storage converter 30 through the second communication interface 208, so that the energy storage converter 30 is disconnected from the power interface 201. Then, the control module 204 controls the state of the switching switch 205, so that the first series interface 202 is connected with the power interface 201. After that, the control module 204 sends a connection instruction to the energy storage converter 30 through the second communication interface 208, so that the energy storage converter 30 is connected with the plurality of battery packs 100 in series in the energy storage system 10.

[0078] It can be understood that when the energy storage converter 30 supplies power to the plurality of battery packs 100 in series, the supply voltage is large, and when the energy storage converter 30 supplies power to the battery pack 100 that needs to be equalized, the supply voltage is small. Therefore, before the control module 204 controls the first equalization interface 203 to be connected with the power interface 201, and before the control module 204 controls the first series interface 202 to be connected with the power interface 201, the control module 204 first controls the energy storage converter 30 to be disconnected from the power interface 201, so as to avoid large current caused by voltage change from passing through the switching switch 205, thereby avoiding damage to the switching switch 205.

[0079] In some embodiments of the present application, as shown in Figure 7As shown, the equalization control device 20 further comprises an operation panel 209 connected with the control module 204, and the control module 204 is further configured to send an equalization prompt information through the operation panel 209 to prompt the user that at least one battery pack 100 in the energy storage system 10 needs equalization, and receive an equalization instruction input by the user through the operation panel 209 to control the corresponding at least one first equalization interface 203 to be connected with the power supply interface 201 according to the equalization instruction. Of course, the operation panel 209 can also send other information, such as power alarm information, and the operation panel 209 can also receive other instructions input by the user, such as stop charging or start charging instructions.

[0080] After the control module 204 determines that at least one battery pack 100 in the energy storage system 10 needs equalization, the control module 204 sends an equalization prompt information to the user through the operation panel 209, and after the user inputs an equalization instruction through the operation panel 209, the control module 204 controls the corresponding at least one first equalization interface 203 to be connected with the power supply interface 201 through the switch 205.

[0081] It should be noted that if the first equalization interface 203 needs to be connected with the plurality of battery packs 100 in turn through manual control, the user can control the first equalization interface 203 to be connected with the battery pack 100 needing equalization prompted by the equalization prompt information, or control the first equalization interface 203 to be connected with the plurality of battery packs 100 needing equalization prompted by the equalization prompt information in turn after receiving the equalization prompt information.

[0082] In some embodiments, the operation panel 209 can include a display panel and a button to display the equalization prompt information and the like through the display panel, and input the equalization instruction and the like through the button. Of course, the present application is not limited to this, and in other embodiments, the operation panel 209 can also include a touch display panel to display information and input instructions through the touch display panel.

[0083] Of course, the present application is not limited to this, and in other embodiments, the equalization control device 20 can also not include the operation panel 209, that is, the equalization control device 20 does not need to send the equalization prompt information to the user, and does not need to equalize based on the equalization instruction input by the user, but automatically controls the battery pack 100 to equalize after determining that the battery pack 100 needs equalization.

[0084] In some embodiments of the present application, as shown in Figure 8 The battery pack 100 can include a series of cell groups 101, a battery management system BMS, a third communication interface 102, a second series interface 103, a second equalization interface 104, and a sampling unit 105.

[0085] The series connection cell group 101 includes a plurality of battery monomers or battery monomer groups connected in series. The positive electrode of the series connection cell group 101 can be connected to the positive electrode of the first battery monomer or battery monomer group in the plurality of battery monomers or battery monomer groups connected in series, and the negative electrode of the series connection cell group 101 can be connected to the negative electrode of the last battery monomer or battery monomer group in the plurality of battery monomers or battery monomer groups connected in series. In addition, the positive electrode of the series connection cell group 101 can be connected to the positive electrode of the battery pack 100, and the negative electrode of the series connection cell group 101 can also be connected to the negative electrode of the battery pack 100.

[0086] The first positive terminal e1 of the second series connection interface 103 and the first positive terminal f1 of the second equalization interface 104 are connected to the positive electrode of the series connection cell group 101, and the first negative terminal e2 of the second series connection interface 103 and the first negative terminal f2 of the second equalization interface 104 are connected to the negative electrode of the series connection cell group 101 through the sampling unit 105. That is, the second series connection interface 103 is connected in parallel with the second equalization interface 104.

[0087] The sampling unit 105 is also connected to the battery management system BMS, and the sampling unit 105 is used to collect the charge and discharge currents of each battery monomer or battery monomer group of the series connection cell group 101, and send the charge and discharge currents to the battery management system BMS, so that the battery management system BMS calculates the SOC of the battery pack 100 according to the charge and discharge currents.

[0088] The battery management system BMS can also be directly connected to the series connection cell group 101 for collecting voltage, temperature and the like of the series connection cell group 101. The battery management system BMS can also be connected to the third communication interface 102.

[0089] As shown in Figure 9 The battery management system BMS can be connected to the control module 204 through the third communication interface 102 and the first communication interface 207 to send the SOC, voltage, temperature and the like to the control module 204. The third communication interface 102 is also a BMS communication interface.

[0090] The second series connection interface 103 is used to be connected to the first series connection interface 202 or the second series connection interface 103 of another battery pack 100. For example, the second positive terminal e3 of the second series connection interface 103 is connected to the second positive terminal of the first series connection interface 202, the second negative terminal e4 of the second series connection interface 103 is connected to the second positive terminal of another second series connection interface 103, and the second negative terminal of the other second series connection interface 103 is connected to the second negative terminal of the first series connection interface 202, so as to realize the series connection of a plurality of battery packs 100 and the first series connection interface 202.

[0091] The second equalization interface 104 is used to be connected with the first equalization interface 203. For example, the second positive terminal of the second equalization interface 104 is connected with the second positive terminal of the first equalization interface 203, and the second negative terminal of the second equalization interface 104 is connected with the second negative terminal of the first equalization interface 203. It can be understood that the first positive terminal and the second positive terminal of the same interface are connected, and the first negative terminal and the second negative terminal are connected, so as to realize the transmission of signals in the same interface.

[0092] It should be noted that in other embodiments, if the equalization control device 20 only includes one first equalization interface 203, the battery pack 100 can only include the second series interface 103 and does not include the second equalization interface 104, or the second series interface 103 can be multiplexed as the second equalization interface 104 to be electrically connected with the first equalization interface 203.

[0093] In some embodiments of the present application, as shown in Figure 10 The control module 204 can include a MCU (Microcontroller Unit, microcontroller unit), and the equalization control device 20 can further include a DC-DC circuit connected with the power interface 201, used to provide the DC output by the power interface 201 to the MCU after DC-DC conversion.

[0094] It should be noted that although the switch 205 switches between the first series interface 202 and the first equalization interface 203, since the switching speed is very fast, it will not cause the MCU to restart after power failure, so as not to affect the normal work of the control module 204.

[0095] The power interface 201 can include a PCS power electrode, and the first series interface 202 and the first equalization interface 203 can include a Pack (battery pack) power electrode. The PCS power electrode and the Pack power electrode both include a positive electrode 1 and a negative electrode 2. The positive electrode 1 can be the first positive terminal or the second positive terminal, and the negative electrode 2 can be the first negative terminal or the second negative terminal.

[0096] The first communication interface 207 can include a 485 circuit, i.e. the remote weighing data acquisition method circuit of the communication interface, the second communication interface 208 can include a CAN (Controller Area Network, Controller Area Network Bus) circuit, and the operation panel 209 includes an LCD (Liquid Crystal Display, Liquid Crystal Display) circuit.

[0097] The second series interface 103 includes a power positive electrode and a power negative electrode, and the second equalization interface 104 can include an equalization socket, which can be a foolproof aviation socket, and the equalization socket is connected in parallel between the power positive electrode and the power negative electrode. The AFE is used to detect the voltage, temperature and current of each battery cell or battery cell group of the series battery cell group 101. The AFE (Analog Front End) and the resistor R constitute a sampling unit 105. The AFE and the MCU communicate and collect the voltage, temperature and current of each battery cell or battery cell group in the series battery cell group 101, and perform calculation of SOC and the like. The AFE and the MCU constitute the BMS.

[0098] Of course, the present application is not limited to this, in actual application, the structure of the battery pack is different, the structures of the second series interface 103, the second equalization interface 104 and the BMS and the like in the battery pack can also be different, and the structure of the equalization control device can also be different, which will not be described here.

[0099] As another optional implementation of the present application, the embodiment of the present application discloses an equalization control system, as shown in Figure 1 and Figure 2 , the equalization control system includes an energy storage converter 30 and an energy storage management unit, and the energy storage management unit includes the equalization control device 20 disclosed in any of the above embodiments.

[0100] Among them, the working voltage range of the energy storage converter 30 covers the voltage range of one or more series battery packs 100 in the energy storage system, and can charge and discharge one or more series battery packs 100 according to instructions.

[0101] As another optional implementation of the present application, the embodiment of the present application discloses an energy storage system, which includes a plurality of series battery packs and the equalization control system as described above.

[0102] As another optional implementation of the present application, the embodiment of the present application discloses an equalization control method, which can be applied to the energy storage system disclosed in any of the above embodiments. The equalization control method can equalize the energy storage system 10 during the assembly, operation or maintenance of the energy storage system 10, as shown in Figure 11 , the equalization control method includes:

[0103] S101: Obtain the parameters of the plurality of battery packs;

[0104] As shown in Figure 1 or Figure 2As shown, the control module 204 can acquire the parameters of the plurality of battery packs 100, which can include one or more of voltage, current, SOC, temperature, etc. For example, if the parameters of the battery pack 100 include voltage, the battery pack 100 can be subjected to voltage equalization according to the parameters; if the parameters of the battery pack 100 include SOC, the battery pack 100 can be subjected to power equalization according to the parameters; if the parameters of the battery pack 100 include voltage and SOC, the battery pack 100 can be subjected to voltage equalization and power equalization according to the parameters.

[0105] In some embodiments, as Figure 5 As shown, the equalization control device 20 further includes a first communication interface 207, which is in communication connection with the plurality of battery packs 100 and is also connected with the control module 204, so that the control module 204 can acquire the parameters sent by the plurality of battery packs 100 through the first communication interface 207.

[0106] S102: According to the parameters of the plurality of battery packs, determine whether the plurality of battery packs need to be equalized;

[0107] After the control module 204 acquires and stores the voltage and SOC parameters of the plurality of battery packs 100 in the energy storage system 10, the voltage and / or SOC of any two battery packs 100 are compared. If the voltage difference and / or SOC difference of any two battery packs 100 is less than a preset value, it means that the plurality of battery packs 100 in the energy storage system 10 do not need to be equalized; if the voltage difference and / or SOC difference of at least two battery packs 100 is greater than or equal to a preset value, such as the voltage difference being greater than or equal to 0.1V and / or the SOC difference being greater than or equal to 5%, it means that the voltage difference and / or SOC difference of the two battery packs 100 is large, and at least one battery pack 100 needs to be equalized to make the voltage difference and / or SOC difference of the at least two battery packs 100 less than the preset value, such as the voltage difference being less than 0.1V and / or the SOC difference being less than 5%.

[0108] S103: When the plurality of battery packs do not need to be equalized, control the first series interface to be connected with the power supply interface, and send the charge and discharge parameters of the plurality of battery packs to the energy storage converter, so that the energy storage converter charges and discharges the plurality of battery packs;

[0109] When the plurality of battery packs 100 do not need to be equalized, the control module 204 controls the first series interface 202 to be connected with the power supply interface 201, and sends the charge and discharge parameters of the plurality of battery packs 100 to the energy storage converter 30, so that the energy storage converter 30 charges and discharges the plurality of battery packs 100.

[0110] S104: when at least one battery pack needs to be balanced, the first balancing interface connected therewith is connected to the power interface, and the charge-discharge parameter of the battery pack needing to be balanced is sent to the energy storage converter, so that the energy storage converter charges and discharges the battery pack needing to be balanced.

[0111] When at least one battery pack 100 needs to be balanced, the control module 204 controls the corresponding at least one first balancing interface 203 to be connected to the power interface 201, that is, controls the at least one first balancing interface 203 connected to the at least one battery pack 100 needing to be balanced to be connected to the power interface 201, and sends the charge-discharge parameter of the battery pack 100 needing to be balanced to the energy storage converter 30, so that the energy storage converter 30 charges and discharges the battery pack 100 needing to be balanced.

[0112] It can be understood that after all the battery packs 100 in the energy storage system 10 are balanced, the voltage difference and / or the SOC difference between any two battery packs 100 are less than the preset value, and the balancing control method further comprises: controlling the first series interface 202 to be connected to the power interface 201, so that the energy storage system 10 performs normal charge-discharge work.

[0113] In some embodiments of the present application, after the corresponding at least one first balancing interface is connected to the power interface, the balancing control method further comprises:

[0114] According to the stored parameters of the plurality of battery packs, a target parameter is set;

[0115] The parameter of the battery pack needing to be balanced is compared with the target parameter;

[0116] According to the comparison result, the battery pack is controlled to be charged or discharged.

[0117] Specifically, the control module 204 sets the target voltage and / or target SOC and the balancing current value of the balancing according to the stored voltage and / or SOC and other parameters of the plurality of battery packs 100; the control module 204 compares the voltage of the battery pack 100 needing to be balanced with the target voltage, and / or compares the SOC of the battery pack 100 needing to be balanced with the target SOC; if the voltage of the battery pack 100 needing to be balanced is greater than the target voltage, and / or the SOC of the battery pack 100 needing to be balanced is greater than the target SOC, the control module 204 controls the battery pack 100 to be discharged to achieve the balancing of the battery pack 100; if the voltage of the battery pack 100 needing to be balanced is less than the target voltage, and / or the SOC of the battery pack 100 needing to be balanced is less than the target SOC, the control module 204 controls the battery pack 100 to be charged to achieve the balancing of the battery pack 100.

[0118] And, in the process of balancing any battery pack, the balancing control method further comprises:

[0119] Regularly collect parameters of the battery packs that are being balanced;

[0120] Compare this parameter with the target parameter;

[0121] If the difference between this parameter and the target parameter is less than the preset value, the battery pack will be controlled to stop charging or discharging.

[0122] Specifically, the control module 204 periodically collects parameters such as voltage and SOC of the battery pack 100, and compares the collected voltage with the target voltage, and / or compares the collected SOC with the target SOC; if the difference between the collected voltage and the target voltage is less than a preset value, and / or the difference between the collected SOC and the target SOC is also less than a preset value, it indicates that the battery pack 100 has been balanced, and the control module 204 controls the battery pack 100 to stop charging or discharging, that is, controls the battery pack 100 to stop balancing.

[0123] Based on this, the energy storage converter 30, which supplies power to the energy storage system 10, can be reused as a balancing power supply for the energy storage system 10. This allows the energy storage converter to provide a larger charging and discharging power, thereby providing a larger charging and discharging balancing current to the battery packs requiring balancing. This improves the balancing efficiency of the energy storage system, shortens the balancing cycle, and reduces the balancing cost. Furthermore, by connecting the control power interface 201 to the first balancing interface 203, the balancing of the energy storage system 10 can be conveniently and quickly achieved, further improving the balancing efficiency of the energy storage system 10.

[0124] In some embodiments of the present invention, controlling the connection of the first serial interface to the power interface includes: controlling the connection of the first end of the switching switch to the second end; controlling the connection of at least one corresponding first equalization interface to the power interface includes: controlling the connection of the first end of the switching switch to the third end.

[0125] like Figure 3 As shown, when multiple battery packs 100 do not require balancing, the first end of the control switch 205 is connected to the second end to control the power interface 201 to be connected to the first serial interface 202. When at least one battery pack 100 requires balancing, the first end of the control switch 205 is connected to the third end to control the power interface 201 to be connected to the corresponding at least one first balancing interface 203.

[0126] In some embodiments of the present invention, controlling the connection of at least one first equalization interface to the power interface further includes controlling the connection of the first terminal of at least one equalization switch to its second terminal.

[0127] like Figure 4As shown, when none of the plurality of battery packs 100 needs to be balanced, the first end of the switching switch 205 is connected to the second end to control the power interface 201 to be connected to the first series interface 202, and when at least one of the battery packs 100 needs to be balanced, the first end of the switching switch 205 is connected to the third end, and the first end of the corresponding at least one balancing switch 206 is connected to the second end to control the power interface 201 to be connected to the corresponding at least one first balancing interface 203.

[0128] In some embodiments of the present application, before the first series interface is controlled to be connected to the power interface, or before the corresponding at least one first balancing interface is controlled to be connected to the power interface, the control module 204 further sends a disconnection instruction to the energy storage converter 30 to control the energy storage converter 30 to be disconnected from the power interface 201; and after the first series interface is controlled to be connected to the power interface, or after the corresponding at least one first balancing interface is controlled to be connected to the power interface, the control module 204 further sends a connection instruction to the energy storage converter 30 to control the energy storage converter 30 to be connected to the power interface.

[0129] For example, when at least one of the battery packs 100 needs to be balanced, the control module 204 first sends a disconnection instruction to the energy storage converter 30 through the second communication interface 208 to control the energy storage converter 30 to be disconnected from the power interface 201, and then controls the first balancing interface 203 connected to the battery pack 100 needing to be balanced to be connected to the power interface 201 by controlling the state of the switching switch 205, and finally sends a connection instruction to the energy storage converter 30 through the second communication interface 208 to control the energy storage converter 30 to be connected to the battery pack 100 needing to be balanced.

[0130] After the balancing of the battery packs 100 is completed, the control module 204 sends a disconnection instruction to the energy storage converter 30 through the second communication interface 208 to control the energy storage converter 30 to be disconnected from the power interface 201, and then controls the first series interface 202 to be connected to the power interface 201 by controlling the state of the switching switch 205, and finally sends a connection instruction to the energy storage converter 30 through the second communication interface 208 to control the energy storage converter 30 to be connected to the plurality of battery packs 100 connected in series in the energy storage system 10.

[0131] It can be understood that when the energy storage converter 30 supplies power to a plurality of battery packs 100 in series, the supply voltage is large, and when the energy storage converter 30 supplies power to the part of the battery pack 100 that needs to be balanced, the supply voltage is small. Therefore, before the control module 204 controls the first balancing interface 203 to be connected to the power supply interface 201, and before the control module 204 controls the first series connection interface 202 to be connected to the power supply interface 201, the energy storage converter 30 will be disconnected from the power supply interface 201 to avoid large current caused by voltage change through the switching switch 205, which can cause damage to the switching switch 205.

[0132] In some embodiments of the present application, as shown in Figure 12 The balancing control method comprises:

[0133] S201: Obtain parameters of a plurality of battery packs, including voltage and SOC;

[0134] S202: Calculate the voltage difference and SOC difference between any two battery packs;

[0135] S203: Determine whether the plurality of battery packs need to be balanced according to the voltage difference and the voltage preset value of any two battery packs; when none of the plurality of battery packs need to be balanced, go to S204; when at least one battery pack needs to be balanced, go to S205;

[0136] S204: Determine whether the plurality of battery packs need to be balanced according to the SOC difference and the SOC preset value of any two battery packs; when none of the plurality of battery packs need to be balanced, go to S213; when at least one battery pack needs to be balanced, go to S209;

[0137] S205: Send a disconnection instruction to the energy storage converter to control the energy storage converter to disconnect from the power supply interface;

[0138] S206: Control the corresponding first balancing interface to be connected to the power supply interface;

[0139] S207: Send a connection instruction to the energy storage converter to control the energy storage converter to be connected to the power supply interface, and send the charge and discharge voltage parameter of at least one battery pack to the energy storage converter, so that the energy storage converter charges and discharges at least one battery pack;

[0140] S208: Regularly collect the voltage of the battery pack being balanced, compare the voltage with the target voltage, and if the difference between the voltage and the target voltage is less than a preset value, control the battery pack to stop charging or discharging, and go to S213;

[0141] S209: Send a disconnection instruction to the energy storage converter to control the energy storage converter to disconnect from the power supply interface;

[0142] S210: connecting the corresponding first equalization interface to the power supply interface;

[0143] S211: sending a connection instruction to the energy storage converter, controlling the energy storage converter to connect to the power supply interface, and sending the charging and discharging voltage parameters of the at least one battery pack to the energy storage converter, so that the energy storage converter charges and discharges the at least one battery pack;

[0144] S212: periodically collecting the SOC of the battery pack being balanced, comparing the SOC with the target SOC, and if the difference between the SOC and the target SOC is less than a preset value, controlling the battery pack to stop charging or discharging, and entering S213;

[0145] S213: sending a disconnection instruction to the energy storage converter, controlling the energy storage converter to disconnect from the power supply interface;

[0146] S214: connecting the first series interface to the power supply interface;

[0147] S215: sending a connection instruction to the energy storage converter, controlling the energy storage converter to connect to the power supply interface, and sending the charging and discharging parameters of the plurality of battery packs to the energy storage converter, so that the energy storage converter charges and discharges the plurality of battery packs.

[0148] The technical features of the above embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present specification.

[0149] The above embodiments only express several implementation manners of the present specification, and the description is specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present specification, some modifications and improvements can be made, which are all within the protection scope of the present specification. Therefore, the protection scope of the present specification should be subject to the appended claims.

Claims

1. A balancing control device applied to an energy storage system, the energy storage system comprising multiple battery packs connected in series, characterized in that, The equalization control device includes: Power interface for connecting to the energy storage converter; The first serial interface is used to connect to the multiple battery packs connected in series; Multiple first equalization interfaces are provided, each of which is connected to a corresponding battery pack. The control module is used to acquire parameters of the multiple battery packs, determine whether the multiple battery packs need to be balanced based on the parameters, and when the multiple battery packs do not need to be balanced, control the first series interface to connect to the power interface and send the charging and discharging parameters of the multiple battery packs to the energy storage converter so that the energy storage converter can charge and discharge the multiple battery packs; when at least one of the battery packs needs to be balanced, control the first balancing interface connected to it to connect to the power interface and send the charging and discharging parameters of the battery pack that needs to be balanced to the energy storage converter so that the energy storage converter can charge and discharge the battery pack that needs to be balanced.

2. The equalization control device according to claim 1, characterized in that, The equalization control device also includes a switching switch; The first end of the switch is connected to the power interface, the second end of the switch is connected to the first series interface, and the third end of the switch is connected to the at least one first equalization interface. The control module is connected to the control terminal of the switching switch; the control module is also used to control the first terminal of the switching switch to be connected to the second terminal when none of the multiple battery packs need to be balanced; and to control the first terminal of the switching switch to be connected to the third terminal when at least one of the battery packs needs to be balanced.

3. The equalization control device according to claim 2, characterized in that, The equalization control device also includes multiple equalization switches; The first end of the equalization switch is connected to the third end of the switching switch, and the second ends of the plurality of equalization switches are respectively connected to the plurality of the first equalization interfaces. The control module is connected to the control terminals of the plurality of equalization switches respectively. The control module is also used to control the first terminal of the equalization switch connected to it to its second terminal when at least one of the battery packs needs to be equalized.

4. The equalization control device according to claim 1, characterized in that, The equalization control device further includes a first communication interface; the first communication interface is communicatively connected to the plurality of battery packs, and the first communication interface is also connected to the control module; the first communication interface is used to receive parameters sent by the plurality of battery packs and transmit the parameters to the control module.

5. The equalization control device according to claim 1, characterized in that, The control module is also used to send a connection command and a disconnect command to the energy storage converter; the connection command is used to connect the energy storage converter to the power interface, and the disconnect command is used to disconnect the energy storage converter from the power interface.

6. The equalization control device according to claim 5, characterized in that, The equalization control device also includes a second communication interface; The second communication interface is used for communication connection with the energy storage converter; The control module is also connected to the second communication interface, and the control module is also used to send connection commands, disconnect commands and battery pack charging and discharging parameters to the energy storage converter through the second communication interface.

7. The equalization control device according to claim 1, characterized in that, The equalization control device also includes an operation panel; The operation panel is connected to the control module. The control module is also used to issue balancing prompt information through the operation panel to prompt the user that at least one of the battery packs in the energy storage system needs to be balanced, and to receive balancing commands input by the user through the operation panel, so as to control at least one corresponding first balancing interface to be connected to the power interface according to the balancing command.

8. The equalization control device according to claim 1, characterized in that, The battery pack includes a second series interface and a second equalization interface. The second series interface and the second equalization interface are connected in parallel. The second series interface is used to connect to the first series interface or the second series interface of another battery pack. The second equalization interface is used to connect to the first equalization interface.

9. A balancing control system applied to an energy storage system, characterized in that, It includes an energy storage converter and an energy storage management unit, wherein the energy storage management unit includes the equalization control device as described in any one of claims 1 to 8.

10. The equalization control system according to claim 9, characterized in that, The operating voltage range of the energy storage converter covers the voltage range of one or more series-connected battery packs in the energy storage system, and it can charge and discharge the one or more series-connected battery packs according to instructions.

11. An energy storage system, characterized in that, It includes multiple battery packs connected in series and a balance control system as described in claim 9 or 10.

12. A balanced control method, applied to the energy storage system of claim 11, characterized in that, The equilibrium control method includes: Obtain the parameters of the plurality of battery packs; Based on the parameters of the multiple battery packs, determine whether the multiple battery packs need to be balanced; When none of the multiple battery packs need to be balanced, the first series interface is connected to the power interface, and the charging and discharging parameters of the multiple battery packs are sent to the energy storage converter so that the energy storage converter can charge and discharge the multiple battery packs. When at least one of the battery packs needs to be balanced, the first balancing interface corresponding to it is connected to the power interface, and the charging and discharging parameters of the battery packs that need to be balanced are sent to the energy storage converter so that the energy storage converter can charge and discharge the battery packs that need to be balanced.

13. The equalization control method according to claim 12, characterized in that, The control of connecting the first serial interface to the power interface includes: controlling the connection of the first end of the switching switch to the second end; The control and its corresponding first equalization interface are connected to the power interface, including: controlling the first terminal of the switching switch to be connected to the third terminal.

14. The equalization control method according to claim 13, characterized in that, The control, which is connected to the first equalization interface corresponding to it, and the power interface are connected, further includes: the first terminal of the equalization switch, which is connected to the battery pack that needs to be equalized, is connected to the second terminal of it.

15. The equalization control method according to claim 12, characterized in that, Before the first series interface is connected to the power interface, or before the first equalization interface connected to it is connected to the power interface, the method further includes: sending a disconnect command to the energy storage converter to control the energy storage converter to disconnect from the power interface. After the first serial interface is connected to the power interface, or after the first equalization interface corresponding to it is connected to the power interface, the method further includes: sending a connection command to the energy storage converter to control the energy storage converter to connect to the power interface.

16. The equalization control method according to claim 12, characterized in that, After the control and its corresponding first equalization interface are connected to the power interface, the system further includes: Based on the stored state parameters of the multiple battery packs, set the target state parameters; The state parameters of the battery pack that need to be balanced are compared with the target state parameters; Based on the comparison results, the battery pack is controlled to charge or discharge.

17. The equalization control method according to claim 12, characterized in that, During the equalization process of any battery pack, the equalization control method further includes: The status parameters of the battery pack are collected periodically; The state parameters are compared with the target state parameters; If the difference between the state parameter and the target state parameter is less than a preset value, the battery pack is controlled to stop charging or discharging.

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