A charging cabinet, a battery pack and a charging system

Abstract

The application provides a charging cabinet, a battery pack and a charging system, and relates to the technical field of charging cabinets. The charging cabinet comprises a power conversion circuit, an input interface and a plurality of output interfaces. The input end of the power conversion circuit is connected to the input interface. In a first time period, the power conversion circuit converts alternating current provided by an alternating current power grid into direct current and charges a plurality of battery packs, so that the state of charge of each battery pack in the plurality of battery packs is any one of at least two states of charge, i.e. a first state of charge or a second state of charge, and the number of battery packs in each state of charge of the at least two states of charge is maintained unchanged in the first time period, the first state of charge is 1, the second state of charge is less than the first state of charge, and the number of battery packs in each state of charge of the at least two states of charge is at least one. While improving the adaptability to business demand fluctuations, the influence on the alternating current power grid can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of charging cabinets, and in particular to a charging cabinet, a battery pack and a charging system. BACKGROUND

[0002] With the aggravation of energy shortage and environmental pollution in modern society, the application of two-wheeled electric vehicles is becoming more and more widespread. The main application scenarios of two-wheeled electric vehicles include but are not limited to personal use, shared travel, delivery of take-out food and delivery of express mail, etc. The battery pack, as the main component of the two-wheeled electric vehicle, is used to provide the required electric energy for the motor of the two-wheeled electric vehicle. How to conveniently, quickly and safely charge the battery pack is one of the main problems faced by electric two-wheeled vehicles.

[0003] In recent years, the shared battery replacement mode has developed rapidly. Shared battery replacement refers to using a charging cabinet to charge multiple battery packs in a centralized manner. When the user's battery pack is insufficient, he or she can go to the charging cabinet to replace a battery pack with sufficient power. The charging cabinet also charges the battery pack with insufficient power replaced by the user. This mode is convenient, fast and safe.

[0004] The charging rate is a measure of the speed of charging, which refers to the current value required by the battery pack to charge to its rated capacity within a specified time. The higher the charging rate, the greater the current for charging the battery pack, and the shorter the time required for the battery pack to charge to its rated capacity. Currently, the charging cabinet generally uses a fixed charging rate when charging the battery pack. However, the business demand for shared battery replacement fluctuates significantly with changes in region and time. The use of a fixed charging rate has poor adaptability to fluctuations in business demand. During the peak period of business, users often need to wait for a long time for the battery pack to be fully charged, which reduces the convenience of shared battery replacement. Increasing the charging rate can reduce the charging time of the battery pack and alleviate business pressure, but it will significantly increase the pressure on the AC power grid and reduce the stability of the AC power grid. SUMMARY

[0005] To solve the above problems, the present application provides a charging cabinet, a battery pack and a charging system, which can improve the adaptability to fluctuations in business demand while reducing the impact on the AC power grid.

[0006] In a first aspect, the application provides a charging cabinet, which includes a power conversion circuit, an input interface and a plurality of output interfaces. The input interface is configured to be connected to an AC power grid. Each of the plurality of output interfaces is configured to be connected to one of a plurality of battery packs. The plurality of output interfaces are connected to an output of the power conversion circuit. An input of the power conversion circuit is connected to the input interface. The power conversion circuit is configured to convert AC power provided by the AC power grid into DC power and charge each of the plurality of battery packs in a first time period, so that each of the plurality of battery packs is in any one of at least two states of charge, i.e., a first state of charge or a second state of charge, and the number of battery packs in each of the at least two states of charge remains unchanged in the first time period. The number of battery packs in each of the at least two states of charge is at least one. The first state of charge is 1, i.e., the battery pack in the first state of charge is fully charged. The second state of charge is less than the first state of charge, i.e., the battery pack in the first state of charge is not fully charged.

[0007] The scheme of the embodiments of the application enables the plurality of battery packs in the charging cabinet to be in at least two states of charge, which at least include the first state of charge and the second state of charge. The first state of charge is 1, and the battery pack in the first state of charge is used to meet the current business demand. The user can directly replace the battery pack in the first state of charge with a battery pack with no power. After the battery pack in the first state of charge is replaced with the battery pack with no power, the battery pack in the second state of charge is charged to the first state of charge and waits to be used, and the battery pack with no power is charged to the second state of charge, so as to maintain the number of battery packs in each state of charge unchanged. By using the scheme of the application, the battery pack in the second state of charge is fully charged only after the battery pack in the first state of charge is replaced. Therefore, compared with the scheme in which all the battery packs in the charging cabinet are always fully charged, the scheme provided by the application reduces the number of battery packs that are fully charged in the charging cabinet, thereby reducing the charging power of the charging cabinet, improving the adaptability to the fluctuation of business demand, and reducing the impact on the AC power grid.

[0008] In a possible implementation, the power conversion circuit charges the battery pack in the plurality of battery packs with the state of charge lower than the second state of charge to the second state of charge at a charging rate lower than the charging rate at which the battery pack in the plurality of battery packs with the state of charge in the second state of charge is charged to the first state of charge.

[0009] That is, the power conversion circuit charges the discharged battery pack to the second state of charge at a small charging rate, reduces the charging power of the charging cabinet, and the power conversion circuit charges the battery pack from the second state of charge to the first state of charge at a large charging rate, thereby quickly meeting the battery pack replacement service demand.

[0010] In a possible implementation, the power conversion circuit is further configured to charge each battery pack after converting the alternating current provided by the alternating current grid into direct current when not in the first time period, so that the state of charge of each battery pack is the first state of charge. The first time period is the peak period of grid load. When not in the first time period, that is, in the off-peak period of grid power consumption, even if the charging cabinet maintains all battery packs in the full power state, the impact on the alternating current grid is smaller. The charging cabinet fully utilizes the power in the off-peak period of alternating current grid load to relieve the power pressure in the peak period of alternating current grid load. When entering the peak period of alternating current grid load, the initial battery packs in the charging cabinet are all in the full power state, which can quickly meet the demand of the battery pack replacement service on one hand, and on the other hand, can reduce the initial charging power of the charging cabinet in the peak period of alternating current grid load, thereby reducing the impact on the alternating current grid.

[0011] In a possible implementation, the charging cabinet is specifically configured to determine the number of battery packs in each state of charge according to the predicted number of battery pack replacements. The scheme of the present application represents the demand of the battery pack replacement service by the predicted number of battery pack replacements. The more the predicted number of battery pack replacements, the greater the demand of the battery pack replacement service; the less the predicted number of battery pack replacements, the smaller the demand of the battery pack replacement service. That is, the scheme of the present application adjusts the number of battery packs in each state of charge according to the demand of the battery pack replacement service, so as to better match the demand of the battery pack replacement service.

[0012] In a possible implementation, the charging cabinet further includes a network interface, and the network interface is configured to connect to a server. The charging cabinet obtains the predicted number of battery pack replacements through the server. In this way, the charging cabinet can automatically update the predicted number of battery pack replacements to better match the demand of the battery pack replacement service. In addition, the charging cabinet can also obtain the time period corresponding to the peak period of alternating current grid load, that is, the first time period.

[0013] In a possible implementation, the number of battery packs in the second state of charge in the plurality of battery packs is negatively correlated with the predicted number of battery pack replacements. The number of battery packs in the first state of charge in the plurality of battery packs is positively correlated with the predicted number of battery pack replacements.

[0014] That is, the greater the battery pack replacement service demand, the greater the number of battery packs in the first state of charge corresponding to the plurality of battery packs, and the greater the number of battery packs in the full state of charge in the charging cabinet, and the battery packs in the full state of charge can be directly replaced for better matching the battery pack replacement service demand.

[0015] In a possible implementation, the power conversion circuit is further configured to adjust a charging rate when charging the plurality of battery packs to better match the battery pack replacement service demand while minimizing the impact on the AC power grid.

[0016] In a possible implementation, the power conversion circuit is configured to positively correlate a charging rate at which the battery packs in the plurality of battery packs with a state of charge lower than the second state of charge are charged to the second state of charge with the predicted number of battery pack replacements, and positively correlate a charging rate at which the battery packs in the plurality of battery packs with a state of charge at the second state of charge are charged to the first state of charge with the predicted number of battery pack replacements.

[0017] The scheme uses the predicted number of battery pack replacements to represent the size of the battery pack replacement service demand. The greater the predicted number of battery pack replacements, the greater the demand for battery pack replacement service, and at this time, the battery packs are charged at a larger charging rate to meet the service demand; the smaller the predicted number of battery pack replacements, the smaller the demand for battery pack replacement service, and at this time, the battery packs are charged at a smaller charging rate to reduce the impact on the AC power grid.

[0018] In a possible implementation, the power conversion circuit gradually reduces the charging rate at which the battery packs in the plurality of battery packs with a state of charge lower than the second state of charge are charged to the second state of charge, and gradually reduces the charging rate at which the battery packs in the plurality of battery packs with a state of charge at the second state of charge are charged to the first state of charge. This can meet the battery pack replacement service demand in the current time period while avoiding damage to the battery packs when continuously charging at a large charging current.

[0019] In a possible implementation, the power conversion circuit gradually increases the charging rate at which the battery packs in the plurality of battery packs with a state of charge lower than the second state of charge are charged to the second state of charge, and gradually increases the charging rate at which the battery packs in the plurality of battery packs with a state of charge at the second state of charge are charged to the first state of charge. This can meet the battery pack replacement service demand in the current time period while avoiding damage to the battery packs when continuously charging at a large charging current.

[0020] In a possible implementation, the at least two states of charge further include a third state of charge, the third state of charge is greater than the second state of charge and less than the first state of charge.

[0021] In a possible implementation, the charging cabinet further includes a first controller. The first controller is configured to acquire detection information sent by the second controller of each battery pack in the plurality of battery packs, and control the power conversion circuit according to the detection information, the detection information representing the state of charge of the corresponding battery pack.

[0022] In a possible implementation, the first controller is further configured to determine the number of battery packs to be charged according to the state of charge of the battery packs in the plurality of battery packs and the number of battery packs in each of the at least two states of charge. The charging rate at which the power conversion circuit charges the battery packs in the plurality of battery packs with the state of charge lower than the second state of charge to the second state of charge is positively correlated with the number of battery packs to be charged; and the charging rate at which the power conversion circuit charges the battery packs in the plurality of battery packs with the state of charge being the second state of charge to the first state of charge is positively correlated with the number of battery packs to be charged.

[0023] At this time, the charging cabinet can adjust the charging rate according to the actual progress of the battery pack replacement service. When a plurality of full-charge battery packs are replaced by discharged battery packs, because the number of battery packs to be charged is relatively large, the charging cabinet can charge the battery packs at a large charging rate to quickly restore the number of battery packs in each state of charge. When the number of battery packs to be charged is relatively small, the charging cabinet can charge the battery packs at a small charging rate to reduce the impact on the power grid.

[0024] In a possible implementation, the power conversion circuit includes an alternating current / direct current conversion circuit and a plurality of direct current / direct current conversion circuits. The input end of the alternating current / direct current conversion circuit is the input end of the power conversion circuit, and the output end of the alternating current / direct current conversion circuit is connected to the input end of the plurality of direct current / direct current conversion circuits. The output end of each direct current / direct current conversion circuit in the plurality of direct current / direct current conversion circuits is configured to be connected to one of the plurality of output interfaces. Each direct current / direct current conversion circuit in the plurality of direct current / direct current conversion circuits converts direct current into direct current and outputs the direct current through the corresponding connected output interface. The first controller controls the alternating current / direct current conversion circuit and the plurality of direct current / direct current conversion circuits according to the detection information to adjust the charging rate when charging each battery pack.

[0025] The charging cabinet itself includes a direct current / direct current conversion circuit, and can output direct current required by the battery pack for charging regardless of whether the battery pack to be charged includes a direct current / direct current conversion circuit, which has wide adaptability.

[0026] In a possible implementation, the battery pack comprises a direct current / direct current conversion circuit and a second controller, and the power conversion circuit is an alternating current / direct current conversion circuit. An output end of the alternating current / direct current conversion circuit is configured to be connected to an input end of the direct current / direct current conversion circuit of each battery pack. The first controller is configured to control the alternating current / direct current conversion circuit according to the detection information, and send a corresponding control signal to the second controller of each battery pack in the plurality of battery packs respectively, so that the second controller of each battery pack in the plurality of battery packs controls the corresponding direct current / direct current conversion circuit according to the control signal.

[0027] At this time, the charging cabinet can not be provided with a direct current / direct current conversion circuit, thereby reducing the hardware cost and power of the charging cabinet, facilitating maintenance of the charging cabinet, and when the direct current / direct current conversion circuit of the battery pack fails, only the battery pack needs to be replaced, without the need to stop the maintenance of the charging cabinet, and the charging cabinet can continue to charge other normal battery packs.

[0028] In a possible implementation, the first time period corresponds to a time period of a peak load of the power grid. The first time period can be pre-set, or the charging cabinet can obtain the first time period through a server.

[0029] In a second aspect, the present application further provides a battery pack, which is charged by the charging cabinet provided in the above implementation, and the battery pack comprises a direct current / direct current conversion circuit, a battery cell and a second controller. An input end of the direct current / direct current conversion circuit is configured to be connected to one output interface in the plurality of output interfaces of the charging cabinet. The direct current / direct current conversion circuit is configured to charge the battery cell after direct current conversion of obtained direct current. The second controller is configured to send detection information representing a state of charge of the battery pack to the charging cabinet.

[0030] The battery pack comprises the direct current / direct current conversion circuit, and the current size for charging the battery cell can be adjusted, so that the charging cabinet for charging the battery pack can not be provided with a direct current / direct current conversion circuit, thereby reducing the hardware cost and power of the charging cabinet, and facilitating maintenance of the charging cabinet.

[0031] In a possible implementation, the second controller is further configured to control the direct current / direct current conversion circuit according to the obtained control signal, so as to adjust a charging rate when charging the battery cell.

[0032] In a third aspect, the present application further provides a battery pack charging system, comprising a battery pack and a charging cabinet. In a possible implementation, the battery pack comprises a direct current / direct current conversion circuit, and at this time, the charging cabinet can comprise a direct current / direct current conversion circuit, or can not comprise a direct current / direct current conversion circuit. In another possible implementation, the battery pack does not comprise a direct current / direct current conversion circuit, and at this time, the charging cabinet comprises a direct current / direct current conversion circuit.

[0033] The multiple battery packs in the charging cabinet are in at least two states of charge, including a first state of charge and a second state of charge. The first state of charge is 1, and the battery in the first state of charge is used to meet the current battery replacement service demand. The user can directly replace the battery pack in the first state of charge with a battery pack with used power. When the battery pack in the first state of charge is replaced with a battery pack with used power, the battery pack in the second state of charge is charged to reach the first state of charge, and the battery pack with discharged power is charged to reach the second state of charge, so as to maintain the number of battery packs in each state of charge unchanged. Because the battery pack in the second state of charge is fully charged only after the battery pack in the first state of charge is replaced, otherwise only the battery pack in the second state of charge needs to be maintained. Even if the charging cabinet charges the battery pack at a high charging rate during the peak load of the alternating current power grid, compared with the current scheme of always fully charging all battery packs in the charging cabinet, the number of battery packs in the full state of charge in the charging cabinet is reduced, thereby reducing the charging power of the charging cabinet, improving the adaptability to the fluctuation of service demand, and reducing the influence on the alternating current power grid. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A schematic charging current-time curve diagram;

[0035] Figure 2 A schematic diagram of a charging system in which a charging cabinet provided by an embodiment of the present application is located;

[0036] Figure 3 A schematic diagram of battery packs in different states of charge provided by an embodiment of the present application Figure 1 ;

[0037] Figure 4 A schematic diagram of battery packs in different states of charge provided by an embodiment of the present application Figure 2 ;

[0038] Figure 5 A schematic diagram of battery packs in different states of charge provided by an embodiment of the present application Figure 3 ;

[0039] Figure 6 A schematic diagram of battery packs in different states of charge provided by an embodiment of the present application Figure 4 ;

[0040] Figure 7 A schematic diagram of battery packs in different states of charge provided by an embodiment of the present application Figure 5 ;

[0041] Figure 8 A schematic diagram of battery packs in different states of charge provided by an embodiment of the present application Figure 6 ;

[0042] Figure 9 A schematic diagram of a battery pack in different states of charge provided by an embodiment of the present application Figure 7 ;

[0043] Figure 10 A relationship between charging current and time provided by an embodiment of the present application Figure 1 ;

[0044] Figure 11 A relationship between charging current and time provided by an embodiment of the present application Figure 2 ;

[0045] Figure 12 A relationship between charging current and time provided by an embodiment of the present application Figure 3 ;

[0046] Figure 13 A schematic diagram of a charging system in which a charging cabinet provided by an embodiment of the present application is located

[0047] Figure 14 A schematic diagram of a charging system in which another charging cabinet provided by an embodiment of the present application is located

[0048] Figure 15 A schematic diagram of a battery pack charging system provided by an embodiment of the present application. DETAILED DESCRIPTION

[0049] In order for those skilled in the art to better understand the technical solutions provided by the embodiments of the present application, the application scenarios of the technical solutions provided by the present application will be introduced first.

[0050] Referring to Figure 1 , this is a schematic relationship diagram between charging current and time.

[0051] The charging process of the charging cabinet on the battery pack mainly includes three stages: a trickle charging stage during 0-t1, a constant current charging stage during t1-t2, and a constant voltage charging stage during t2-t3.

[0052] The trickle charging stage is a low-voltage pre-charging stage, which is used to protect the battery pack. The charging current in the trickle charging stage is small, and the charging time is short. The charging current value in the trickle charging stage is shown in the figure as 0.1C.

[0053] Among them, C (Capacity, capacity) represents the size of the charging current when the battery pack is charging. 1C represents the current value required for the battery pack to be charged from a discharged state to a full charge state in one hour.

[0054] The battery pack can be represented by a state of charge (SOC) value, which is a ratio of the remaining capacity of the battery pack to the capacity of the battery pack when fully charged, and the value ranges from 0 to 1. When the SOC is 0, it means that the battery pack has been completely discharged, and when the SOC is 1, it means that the battery pack has been fully charged. Therefore, 1C also represents the current value required by the battery pack to charge from a completely discharged state to an SOC of 1 in 1 hour.

[0055] The specific charging current value represented by 1C is related to the capacity of the battery pack. For example, for a battery pack with a capacity of 20 Ampere-hours (Ah), the charging current value represented by 0.1C is 2A, and the charging current value represented by 1C is 20A. For a battery pack with a capacity of 10 Ah, the charging current value represented by 0.1C is 1A, and the charging current value represented by 1C is 10A.

[0056] The constant current charging phase during t1-t2 uses a fixed charging current value, i.e., a fixed charging rate to charge the battery pack. In the figure, the charging current value is fixed at 1C, but it can also be fixed at other values. The length of the constant current charging phase is inversely proportional to the charging current value (i.e., the charging rate).

[0057] The constant voltage charging phase during t2-t3 uses a fixed voltage to charge the battery pack, and the process lasts for a short time.

[0058] In summary, the duration of the constant current charging phase occupies the main part of the battery pack charging time, i.e., the main factor determining the length of the battery pack charging time is the length of the constant current charging process of the battery pack.

[0059] The demand for battery replacement services fluctuates significantly with region and time. The use of a fixed charging rate has poor adaptability to the fluctuations in demand for battery replacement services. When the demand for battery replacement services is high, the number of battery replacements is large, and users often have to wait for a long time for the battery to be fully charged, reducing the convenience of shared battery replacement and affecting user experience. To alleviate the above problems, the charging rate during battery charging is generally increased, i.e., the charging current during the constant current charging phase is increased, but this method significantly increases the power during battery charging, increases the load on the AC power grid during the peak period of the AC power grid, and reduces the stability of the AC power grid.

[0060] To solve the above problems, the application provides a charging cabinet, a battery pack and a charging system. Each battery pack in the charging cabinet is in at least two states of charge, including a first state of charge and a second state of charge. The first state of charge is 1, the second state of charge is less than the first state of charge, and the number of battery packs in each state of charge is at least one. The battery pack in the first state of charge is directly replaced to meet the business demand. When the battery pack in the first state of charge is replaced by a battery pack with exhausted power, the battery pack in the second state of charge is charged to the first state of charge and waits to be used. The battery pack with exhausted power is charged to the second state of charge to maintain the number of battery packs in each state of charge. By using the scheme, even if the charging cabinet charges the battery pack at a high charging rate during the peak load of the alternating current power grid, compared with the current scheme of always charging all battery packs in the charging cabinet to full capacity, the number of battery packs in the full state of charge in the charging cabinet is reduced, thereby reducing the charging power of the charging cabinet and further reducing the impact on the alternating current power grid.

[0061] The terms "first", "second", etc. in the following description of the application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0062] In the present application, unless otherwise specified and limited, the term "connection" should be understood broadly, for example, "connection" can be fixed connection, can also be detachable connection, or integral; can be direct connection, or indirect connection through intermediate medium.

[0063] The application provides a charging cabinet for charging battery packs, which will be specifically described below in conjunction with the drawings. It can be understood that for the application scenario of the technical solution of the application, the fully charged battery pack in the charging cabinet is always replaced by a discharged battery pack, that is, the total number of connected battery packs in the charging cabinet remains unchanged before and after the battery pack replacement service, and the following description is based on the example that the number of connected battery packs in the charging cabinet remains unchanged before and after the battery pack replacement service.

[0064] Referring to Figure 2 The figure is a schematic diagram of a charging system in which a charging cabinet provided by an embodiment of the application is located.

[0065] The charging system includes a charging cabinet 10 and a plurality of battery packs 20.

[0066] The charging cabinet 10 includes a power conversion circuit 101, an input interface 102 and a plurality of output interfaces 103.

[0067] The input interface 102 is configured to be connected with the AC power grid 30, and each output interface 103 is configured to be connected with one battery pack 20. The number of output interfaces 103 included in one charging cabinet 10 is not limited in the embodiments of the present application.

[0068] The input end of the power conversion circuit 101 is connected with the input interface 102, and the output end of the power conversion circuit 101 is connected with each output interface 103. The power conversion circuit 101 is configured to convert the AC power provided by the AC power grid 30 into DC power to charge each battery pack 20.

[0069] The working principle of the charging cabinet 10 is described below. For the convenience of description, the charging cabinet 10 can accommodate 12 battery packs is taken as an example for description, that is, the charging cabinet 10 includes 12 output interfaces and can simultaneously charge 12 battery packs, and the principle when the number of battery packs accommodated by the charging cabinet is not 12 is similar, which is not described herein again in the embodiments of the present application.

[0070] Referring to Figure 3 and Figure 4 together, Figure 3 the schematic diagrams of the battery packs in different states of charge provided by the embodiments of the present application are shown in Figure 1 ; Figure 4 Figure 2 .

[0071] In the first time period, the power conversion circuit charges each battery pack to make the state of charge of each battery pack be any one of at least two states of charge, that is, the first state of charge or the second state of charge. The first time period in the embodiments of the present application is when the load of the AC power grid is high, the first time period can be preset, and the first time period can be adjusted and modified according to actual conditions.

[0072] Figure 3 and Figure 4 the schematic diagrams including two states of charge are shown, and the number of battery packs in each state of charge is at least one.

[0073] In the embodiments of the present application, the state of charge of the battery pack in the first state of charge is 100%, that is, the battery pack is fully charged to be directly replaced for use. The state of charge of the battery pack in the second state of charge is relatively low, and the second state of charge is not limited in the embodiments of the present application, for example, the second state of charge is 10%.

[0074] The number of battery packs in the first state of charge and the number of battery packs in the second state of charge are not limited in the embodiments of the present application, for example, Figure 3 in the first state of charge is 4, and the number of battery packs in the second state of charge is 8. For another example, Figure 4 ​The number of battery packs in the first state of charge is 8, and the number of battery packs in the second state of charge is 4.

[0075] In actual application, the number of battery packs in the first state of charge and the number of battery packs in the second state of charge can be determined by the battery pack expected replacement number, which represents the size of the battery pack replacement service demand. The higher the battery pack expected replacement number, the higher the battery pack replacement service demand, and at this time, the number of battery packs in the first state of charge is correspondingly larger. Figure 4 The corresponding battery pack expected replacement number is greater than Figure 3 The corresponding battery pack expected replacement number.

[0076] When the battery pack in the first state of charge is replaced by a battery pack with exhausted power, the battery pack in the second state of charge is charged to reach the first state of charge, and the charging cabinet charges the battery pack with exhausted power to make the state of charge of the battery pack reach the second state of charge, so as to maintain the number of battery packs in each state of charge unchanged.

[0077] In this application, maintaining the number of battery packs in each state of charge unchanged is the state desired to be achieved in the process of replacing battery packs in the charging cabinet. In some cases, for example, when a user replaces a battery pack that is not fully charged with a fully charged battery pack, it may actually result in the number of battery packs in the first state of charge being greater than the number of battery packs in the first state of charge desired to be maintained, and at this time the battery cabinet will not discharge the battery pack in order to maintain the number of battery packs in the first state of charge. For another example, when a user replaces a battery pack in the second state of charge in the battery cabinet with a battery pack having a state of charge greater than the second state of charge, at this time there exists a battery pack having a state of charge higher than the second state of charge and lower than the first state of charge.

[0078] The scheme provided in the embodiments of the application is that the battery pack in the second state of charge is charged to the first state of charge only after the battery pack in the first state of charge is replaced, otherwise it only needs to maintain the second state of charge, which is lower than the first state of charge. Therefore, even if the charging cabinet charges the battery pack at a higher charging rate during the peak load of the AC power grid, compared with the current scheme of always charging all battery packs in the charging cabinet to full capacity, the number of battery packs maintained in the charging cabinet in the full state of charge is reduced, which can meet the battery pack replacement service demand while reducing the charging power of the charging cabinet, and further reducing the impact on the AC power grid.

[0079] The charging rate of the charging cabinet when charging the battery pack to different states of charge can be the same or different. The implementation manner when the charging rate is different is described below.

[0080] In some embodiments, when the battery pack in the first state of charge is replaced for use, the power conversion circuit of the charging cabinet charges the discharged battery pack to the second state of charge at a first charging rate. The charging rate of the battery pack from the second state of charge to the first state of charge is a second charging rate, which is greater than the first charging rate.

[0081] That is, the discharged battery pack is charged to the second state of charge at a small charging rate to reduce the charging power of the charging cabinet, and the battery pack is charged from the second state of charge to the first state of charge at a large charging rate, thereby being able to quickly meet the battery replacement service demand. Thus, the above charging method with variable charging rate further reduces the influence on the AC power grid.

[0082] In order to fully utilize the electricity during the low load period of the AC power grid to relieve the electricity demand during the peak load period of the AC power grid, the power conversion circuit of the charging cabinet converts the AC power provided by the AC power grid into DC power to charge each battery pack when not in the first time period, that is, not in the peak load period of the AC power grid, but in the low load period of the AC power grid, so that each battery pack is in the first state of charge, that is, each battery pack is fully charged. Fully utilize the electricity during the low load period of the AC power grid, because the AC power grid pressure is small during this period, even if the charging cabinet maintains all battery packs in the full state of charge, the influence on the AC power grid is also small. When entering the peak load period of the AC power grid, the initial battery packs in the charging cabinet are all in the full state of charge, which can quickly meet the demand of the battery replacement service on one hand, and on the other hand, it can also reduce the initial charging power of the charging cabinet during the peak load period of the AC power grid, thereby reducing the influence on the AC power grid.

[0083] In the above description, the state of charge of the battery pack is taken as one of the first state of charge or the second state of charge for example, in actual application, the state of charge of the battery pack can also be other states of charge, which will be described in detail below.

[0084] Referring to Figure 5 , the figure is a schematic diagram of the battery pack in different states of charge provided by the embodiment of the application Figure 3 .

[0085] The first state of charge, the second state of charge and the third state of charge are illustrated in the different states of charge. Among them, the third state of charge is greater than the second state of charge and less than the first state of charge. Since the third state of charge is greater than the second state of charge, the time for charging the state of charge of the battery pack from the third state of charge to the first state of charge is less than the time for charging the state of charge of the battery pack from the second state of charge to the first state of charge at the same charging rate, so Figure 5 the scheme shown inFigure 4 Compared with the prior art, the time required for charging the battery pack to full capacity when the demand for battery pack replacement service is large is shortened.

[0086] When the battery pack in the first state of charge is replaced by a battery pack in the discharged state, the battery pack in the third state of charge can be charged to the first state of charge at a large charging rate for standby, the battery pack in the second state of charge is charged to the third state of charge, and the charging cabinet charges the battery pack in the discharged state to the second state of charge, thereby maintaining the number of battery packs in each state of charge unchanged.

[0087] In some embodiments, the charging rate of the battery pack from the third state of charge to the first state of charge is a first charging rate, the charging rate of the battery pack from the second state of charge to the state of charge region is a second charging rate, and the charging rate of the battery pack from the discharged state to the second state of charge is a third charging rate, the first charging rate is greater than the second charging rate, and the second charging rate is greater than the third charging rate, thereby further reducing the charging power of the charging cabinet while quickly meeting the demand for battery pack replacement service, and thus further reducing the impact on the AC power grid.

[0088] Referring to Figure 6 , the figure is a schematic diagram of the battery pack in different states of charge provided by the embodiment of the application Figure 4 .

[0089] The different states of charge shown in the figure also include a plurality of intermediate states of charge. The plurality of intermediate states of charge is greater than the second state of charge and less than the first state of charge, and the plurality of intermediate states of charge presents a step distribution from low to high.

[0090] Referring to Figure 5 and Figure 6 , when the number of battery packs in the plurality of intermediate states of charge in Figure 5 , and the number of battery packs in the third state of charge in Figure 6 are the same, Figure 5 the average state of charge of each battery pack in the plurality of intermediate states of charge shown in Figure 7 to Figure 9 , and the average state of charge of each battery pack in the third state of charge shown in are similar, so when the above two implementation manners are adopted, the power of the battery cabinet is similar, that is, the technical effect of reducing the impact on the AC power grid is similar.

[0091] In actual application, the first time period can include a time period with high battery pack replacement service demand, a time period with ordinary battery pack replacement service demand, and a time period with low battery pack replacement service demand. The number of battery packs in each state of charge can be adjusted in different service demand time periods. The scheme provided in the embodiments of the present application is to better match the demand of the battery pack replacement service, and the number of battery packs in each state of charge changes with the change of the demand of the battery pack replacement service. The following will be specifically described.

[0092] The scheme provided in the embodiments of the present application uses the predicted replacement number of battery packs to represent the demand of the battery pack replacement service. The more the predicted replacement number of battery packs is, the greater the demand of the battery pack replacement service is; the less the predicted replacement number of battery packs is, the smaller the demand of the battery pack replacement service is.

[0093] In some embodiments, the charging cabinet can count the actual replacement number of battery packs in each time period in the past history period, obtain the battery pack replacement number corresponding to each time period by averaging, and take the average of the actual replacement number of battery packs as the predicted replacement number of battery packs, that is, the predicted replacement number of battery packs corresponding to different service demand time periods is obtained.

[0094] For example, the charging cabinet records the actual replacement number of battery packs in the peak time period of the battery pack replacement service demand in the past thirty days, takes the average of the thirty actual replacement numbers of battery packs as the predicted replacement number of battery packs corresponding to the peak time period of the battery pack replacement service demand, and the charging cabinet can also update the predicted replacement number of battery packs every day.

[0095] In another implementation manner, the charging cabinet further includes a network interface, and the network interface is used to connect a server, so that the charging cabinet can automatically obtain and update the predicted replacement number of battery packs corresponding to each time period through the server. The charging cabinet can also obtain the time period corresponding to the peak of the alternating current power grid load through the server, that is, obtain the first time period.

[0096] After the charging cabinet determines the predicted replacement number of battery packs, the number of battery packs corresponding to each state of charge is further determined. The corresponding relationship between the number of battery packs corresponding to each state of charge and the predicted replacement number of battery packs is pre-calibrated and stored, for example, can be stored in the form of a data table or a function relationship formula, and the embodiments of the present application do not make specific limitation here.

[0097] Referring to FIG. 1 and FIG. 2, Figure 7 FIG. 1 shows a schematic diagram of battery packs in different states of charge. Figure 8 FIG. 2 shows the number distribution of battery packs in each state of charge in a battery pack replacement service demand trough period; Figure 9 FIG. 3 shows the number distribution of battery packs in each state of charge in a battery pack replacement service demand ordinary period;Figure 3 the number of battery packs in each state of charge during a peak period of battery pack replacement service demand.

[0098] The number of battery packs in different states of charge is related to the predicted number of battery pack replacements. Specifically, the number of battery packs in the second state of charge is negatively related to the predicted number of battery pack replacements; the number of battery packs in the first state of charge is positively related to the predicted number of battery pack replacements. That is, the greater the battery pack replacement service demand, the greater the number of battery packs in the first state of charge, and the greater the number of battery packs in the fully charged state that are ready for use in the charging cabinet.

[0099] The number of battery packs in the intermediate state of charge can remain unchanged or be negatively related to the predicted number of battery pack replacements, which is not limited in the embodiments of the present application.

[0100] In summary, compared with the current scheme of always keeping all battery packs in the charging cabinet fully charged, the scheme provided by the embodiments of the present application reduces the number of battery packs in the fully charged state maintained in the charging cabinet, thereby reducing the charging power of the charging cabinet, improving the adaptability to service demand fluctuations, and reducing the impact of the charging cabinet on the alternating current power grid.

[0101] The charging cabinet can not only adjust the number of battery packs in each state of charge according to the size of battery pack replacement service demand, but also adjust the charging rate of the charging cabinet when charging the battery pack according to the size of battery pack replacement service demand. The following takes Figure 4 and Figure 10 as examples for illustration.

[0102] Referring to Figure 1 , the figure is a relationship between the charging current and time provided by the embodiments of the present application Figure 11 .

[0103] The charging rate of the power conversion circuit of the charging cabinet when charging the battery pack is positively related to the predicted number of battery pack replacements, that is, positively related to the size of battery pack replacement service demand.

[0104] When the predicted number of battery pack replacements is large, in order to meet the battery pack replacement service demand, the charging cabinet charges the battery pack at a large charging rate to ensure that the battery pack replacement service demand is met, which is specifically illustrated by examples as follows.

[0105] When the battery pack is in a time period with a small number of expected replacements, the charging cabinet charges the battery pack to the second state of charge at a first charging rate, and charges the battery pack from the second state of charge to the first state of charge at a second charging rate. When the battery pack is in a time period with a large number of expected replacements, the charging cabinet charges the battery pack to the second state of charge at a third charging rate, and charges the battery pack from the second state of charge to the first state of charge at a fourth charging rate. The third charging rate is greater than the first charging rate, and the fourth charging rate is greater than the third charging rate. The above describes an implementation of adjusting the charging rate according to the number of expected replacements of the battery pack. The following describes an implementation of adjusting the charging rate in the same time period of a service requirement.

[0106] In a possible implementation, in the same time period of a service requirement, the charging rate of the power conversion circuit of the charging cabinet when charging the battery pack is positively correlated with the number of battery packs currently to be charged. The following is an example for illustration.

[0107] Taking a time period with a large number of expected replacements of the battery pack as an example, when two battery packs in the full state of charge are replaced for use, the charging cabinet charges two discharged battery packs to the second state of charge at a first charging rate, charges two battery packs in the second state of charge to the first state of charge at a second charging rate, and the number of battery packs currently to be charged is four. When three battery packs in the full state of charge are replaced for use, the charging cabinet charges three discharged battery packs to the second state of charge at a third charging rate, charges three battery packs in the second state of charge to the first state of charge at a fourth charging rate, and the number of battery packs currently to be charged is six. The third charging rate is greater than the first charging rate, and the fourth charging rate is greater than the third charging rate, so as to recover the number of battery packs in each state of charge more quickly.

[0108] Therefore, in the time period with a large number of expected replacements of the battery pack, the charging rate of the charging cabinet for the battery pack can be adjusted, and the following scenarios can occur Figure 12 or Figure 11 The charging rate is positively correlated with the number of battery packs to be charged. The corresponding relationship between the charging rate and the number of battery packs to be charged is pre-calibrated and stored, for example, in the form of a data table or a function relationship, which is not limited in the embodiments of the present application.

[0109] The charging cabinet can determine the number of battery packs to be charged according to the state of charge of each battery pack and the number of battery packs in each state of charge.

[0110] In another possible implementation, refer to Figure 12 The charging current-time relationship diagram is shown in FIG. 6. In the same time period of business demand, the charging rate of the power conversion circuit in the charging cabinet when charging the battery pack is adjustable. Specifically, in order to meet the battery pack replacement business demand in the current time period and avoid damaging the battery pack when continuously charging with a large charging current, the charging rate of the charging cabinet to the battery is gradually reduced. For example, the battery pack is first charged at a high charging rate, and then charged at a charging rate gradually reduced according to a gradient.

[0111] In another possible implementation, refer to Figure 13 The charging current-time relationship diagram is shown in FIG. 6. In the same time period of business demand, the charging rate of the power conversion circuit in the charging cabinet when charging the battery pack is adjustable. Specifically, in order to meet the battery pack replacement business demand in the current time period and avoid damaging the battery pack when continuously charging with a large charging current, the charging rate of the charging cabinet to the battery is gradually reduced. For example, the battery pack is first charged at a high charging rate, and then charged at a charging rate gradually reduced according to a gradient.

[0112] The above describes the manner in which the charging cabinet adjusts the charging rate. The following specifically describes the implementation of the charging cabinet and the battery pack.

[0113] The battery pack can be divided into intelligent battery packs and non-intelligent battery packs. The intelligent battery pack includes a direct current / direct current conversion circuit and has the ability to adjust the current for charging the battery core itself. The non-intelligent battery pack includes a direct current / direct current conversion circuit and can only passively use the externally input current to charge the battery core itself. The following first describes the implementation when the charging cabinet charges the non-intelligent battery pack.

[0114] Refer to Figure 14 The figure is a schematic diagram of a charging system in which a charging cabinet according to an embodiment of the present application is located.

[0115] At this time, the power conversion circuit of the charging cabinet 10 specifically includes an alternating current (AC) / direct current (DC) conversion circuit 101a and a plurality of direct current / direct current conversion circuits 101b. The charging cabinet 10 further includes a first controller 102.

[0116] The input end of the alternating current / direct current conversion circuit 101a is the input end of the power conversion circuit, and the output end of the alternating current / direct current conversion circuit 101a is connected to the input end of the plurality of direct current / direct current conversion circuits 101a.

[0117] The output end of each direct current / direct current conversion circuit 101b is used to connect an output interface.

[0118] The direct current / direct current conversion circuit 101b is configured to convert the obtained direct current into direct current and output the direct current through the corresponding output interface.

[0119] The battery pack 20 connected to the output interface of the charging cabinet is a non-intelligent battery pack, and includes a battery cell 201 and a second controller 202.

[0120] The battery cell 201 is configured to store electric quantity. The second controller 202 is configured to communicate with the first controller 201. The second controller 202 is capable of detecting the state of charge of the battery cell 201 and sending detection information representing the detection result of the state of charge to the first controller 201.

[0121] The charging cabinet and each battery pack are capable of power transmission and signal transmission through the corresponding output interface. The power transmission refers to charging the battery pack by the charging cabinet. The signal transmission refers to that the first controller 102 of the charging cabinet is capable of obtaining the detection information representing the state of charge of the battery pack sent by the second controller 202 of the battery pack in real time.

[0122] The first controller 102 determines the current state of charge of the corresponding battery pack according to the obtained detection information representing the state of charge of the battery pack.

[0123] The first controller 102 and each second controller 202 in the embodiments of the present application can be an Application Specific Integrated Circuit (ASIC), a Programmable Logic Device (PLD), a Digital Signal Processor (DSP) or a combination thereof. The PLD can be a Complex Programmable Logic Device (CPLD), a Field-programmable Gate Array (FPGA), a Generic Array Logic (GAL) or any combination thereof, and the embodiments of the present application do not make a specific limitation in this regard.

[0124] The power switching device included in the AC / DC conversion circuit 101a and the DC / DC conversion circuit 101b can be an Insulated Gate Bipolar Transistor (IGBT), a Metal Oxide Semiconductor Filed Effect Transistor (MOSFET), a Silicon Carbide Metal Oxide Semiconductor (SiC MOSFET), or the like, which is not limited in the embodiments of the present application.

[0125] The first controller 102 controls the power switching device in the AC / DC conversion circuit and the plurality of DC / DC conversion circuits to adjust the charging rate when charging the battery pack. The first controller 102 is further configured to determine the number of battery packs to be charged according to the state of charge of each battery pack and the number of battery packs in each state of charge.

[0126] The implementation of the charging cabinet when charging the intelligent battery pack is described below.

[0127] Referring to Figure 14 , which is a schematic diagram of a charging system provided by another charging cabinet according to an embodiment of the present application.

[0128] The power conversion circuit of the charging cabinet 10 specifically includes an AC / DC conversion circuit 101a. The charging cabinet 10 further includes a first controller 102.

[0129] The input end of the AC / DC conversion circuit 101a is the input end of the power conversion circuit, and the output end of the AC / DC conversion circuit 101a is connected to each output interface of the charging cabinet 10.

[0130] The battery pack 20 connected to the output interface of the charging cabinet is an intelligent battery pack, which includes a DC / DC conversion circuit 101a, a battery cell 201, and a second controller 202.

[0131] The battery cell 201 is configured to store electricity. The input end of the DC / DC conversion circuit 101a is configured to be connected to the output interface of the charging cabinet, and the output end of the DC / DC conversion circuit 101b is connected to the battery cell. The DC / DC conversion circuit 101b is configured to charge the battery cell 201 by converting the obtained DC power.

[0132] The second controller 202 is used to communicate with the first controller 201, detect the state of charge of the battery cell 201, and send detection information characterizing the detection result of the state of charge to the first controller 201. In addition, the second controller 202 is also used to control the operating state of the corresponding DC / DC converter circuit 101b.

[0133] The charging cabinet 10 and each battery pack can transmit power and signals through corresponding output interfaces. Power transmission refers to the charging cabinet transmitting DC power to each battery pack, and signal transmission refers to the charging cabinet's first controller 102 being able to obtain the detection information sent by the battery pack's second controller 202 in real time, and send corresponding control signals to the second controller 202 of each battery pack.

[0134] The first controller 102 is also configured to determine the current state of charge of the battery pack corresponding to the acquired detection information based on the acquired detection information, and to generate a control signal and send the control signal to the corresponding second controller 202 so that the second controller 202 controls the corresponding DC / DC converter circuit 101b according to the control signal.

[0135] The first controller 102 is also used to determine the number of battery packs to be charged based on the state of charge of each battery pack and the number of battery packs in each state of charge.

[0136] When the charging cabinet adopts Figure 13 The implementation shown is compared to Figure 13 This implementation method avoids setting up DC / DC conversion circuits on the charging cabinet side, reducing the hardware cost and power of the charging cabinet, and also facilitates the maintenance of the charging cabinet. Furthermore, when the DC / DC conversion circuit of the battery pack fails, only the battery pack needs to be replaced, without the need to shut down the charging cabinet for maintenance. The charging cabinet can continue to charge other normal battery packs.

[0137] In one possible implementation, Figure 14 The charging cabinet shown can also be used for Figure 13 The battery pack 20 shown (i.e., the smart battery pack) is being charged. Figure 13 The charging cabinet shown has wide compatibility because... Figure 14 The charging cabinet shown includes a DC / DC converter circuit. Regardless of whether the battery pack being charged includes a DC / DC converter circuit, the charging cabinet can output the DC power required for charging the battery pack.

[0138] In summary, the technical scheme provided in the application uses the predicted replacement number of the battery pack to represent the size of the battery replacement service demand, and then adjusts the charging rate of the battery pack and the number of battery packs in each state of charge according to the fluctuation of the battery replacement service demand. The size of the predicted replacement number of the battery pack can be determined by historical experience or big data analysis. This scheme responds to the peak load shifting strategy of the power grid. Under the premise of meeting the battery replacement service demand, as many battery charging processes as possible are transferred from the peak period of the alternating current grid load to the trough period of the alternating current grid load to minimize the impact on the alternating current grid. At the same time, the charging rate of the battery pack when the charging cabinet charges the battery pack can be adjusted to better adapt to the changes in the battery replacement service demand and prevent no battery pack being available during the service peak period.

[0139] The embodiment of the application further provides an intelligent battery pack, which is specifically described below.

[0140] Continuing to refer to Figure 15 The battery pack provided in the embodiment of the application is an intelligent battery pack, which can adjust the size of the charging current itself. The battery pack 20 comprises a direct current / direct current conversion circuit 101a, a battery cell 201, and a second controller 202.

[0141] The battery cell 201 is configured to store electric quantity.

[0142] The input end of the direct current / direct current conversion circuit 101a is connected to the output interface of the charging cabinet, and the output end of the direct current / direct current conversion circuit 101b is connected to the battery cell. The direct current / direct current conversion circuit 101b is configured to charge the battery cell 201 after direct current conversion of the obtained direct current.

[0143] The second controller 202 is configured to control the working state of the corresponding direct current / direct current conversion circuit 101b, and to detect the state of charge of the battery cell 201 in real time and send detection information representing the detection result of the state of charge to the first controller 102.

[0144] In addition, the second controller 202 is further configured to receive the control signal sent by the first controller 102 and control the corresponding direct current / direct current conversion circuit 101b according to the control signal.

[0145] The battery pack comprises a direct current / direct current conversion circuit, which can adjust the size of the charging current of the battery cell. Therefore, the charging cabinet for charging the battery pack can not be provided with a direct current / direct current conversion circuit, thereby reducing the hardware cost and power of the charging cabinet and facilitating the maintenance of the charging cabinet.

[0146] Based on the charging cabinet and the battery pack provided in the above embodiment, the embodiment of the application further provides a battery pack charging system, which is specifically described below with reference to the accompanying drawings.

[0147] Referring to Figure 13FIG. 1 is a schematic diagram of a battery pack charging system according to an embodiment of the present application.

[0148] The battery pack charging system 105 includes a charging cabinet 10 and a plurality of battery packs 20.

[0149] In one possible implementation, the charging cabinet 10 is as shown in Figure 14 , at which time the battery pack 20 can be a smart battery pack or a non-smart battery pack. In another possible implementation, the charging cabinet 10 is as shown in ​ , at which time the battery pack 20 is a smart battery pack and is capable of adjusting the size of the charging current by itself.

[0150] For specific implementation and working principle of the charging cabinet 10 and the battery pack 20, refer to the above description, which will not be repeated here.

[0151] In summary, when the battery packs are charged by the charging cabinet, the battery packs being charged in the charging cabinet are in at least two states of charge, and the at least two states of charge include a first state of charge and a second state of charge. The battery in the first state of charge is used to meet the current battery replacement service demand, and the user can directly replace the battery pack in the first state of charge with a battery pack with no power. After the battery pack in the first state of charge is replaced with a battery pack with no power, the battery pack in the second state of charge is charged to reach the first state of charge, and the battery pack with no power is charged to reach the second state of charge to maintain the number of battery packs in each state of charge. Because the battery pack in the second state of charge will be fully charged only after the battery pack in the first state of charge is replaced, otherwise it only needs to be maintained in the second state of charge. Even if the charging cabinet charges the battery pack at a high charging rate during the peak load of the AC power grid, compared with the current solution of always fully charging all battery packs in the charging cabinet, the number of battery packs in the full state of charge in the charging cabinet is reduced, thus reducing the charging power of the charging cabinet. While improving the adaptability to service demand fluctuations, it can also reduce the impact on the AC power grid.

[0152] Further, the charging cabinet can also charge the battery pack with an adjustable charging current (i.e., a charging rate). On one hand, the charging cabinet adjusts the charging rate of the battery pack according to the size of the battery pack replacement service demand. Specifically, the charging rate of the battery pack when the charging cabinet charges the battery pack is positively correlated with the expected number of battery pack replacements. On the other hand, the charging cabinet can also adjust the charging rate within the same service demand time period. Specifically, in some embodiments, the charging rate of the battery pack when the power conversion circuit in the charging cabinet charges the battery pack is positively correlated with the number of battery packs to be charged at present. In other embodiments, in order to avoid damaging the battery pack when continuously charging with a large charging current, the charging cabinet can charge the battery pack with a gradually decreasing or gradually increasing charging rate.

[0153] It should be understood that, in the present application, "at least one" means one or more, and "multiple" means two or more. "And / or" is used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, "A and / or B" can mean that there are three cases of only A, only B, and A and B at the same time, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b or c can mean a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0154] Each of the embodiments in the specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the difference from other embodiments. The device embodiments described above are only illustrative, and the units and modules described as separate components can or can not be physically separated. In addition, part or all of the units and modules can be selected according to actual needs to achieve the purpose of the embodiment. Those skilled in the art can understand and implement without creative labor.

[0155] The above is only a specific embodiment of the present application. It should be noted that for those skilled in the art, without departing from the principles of the present application, several improvements and refinements can be made, which should also be considered as the protection scope of the present application.

Claims

1. A charging cabinet characterized by, The charging cabinet is used for connecting a plurality of battery packs, and the charging cabinet comprises a power conversion circuit, an input interface and a plurality of output interfaces; The input interface is used for connecting an alternating current power grid, and each of the plurality of output interfaces is used for connecting one of the plurality of battery packs; The plurality of output interfaces are used for connecting the output end of the power conversion circuit; The input end of the power conversion circuit is used for connecting the input interface; The power conversion circuit is used for converting alternating current provided by the alternating current power grid into direct current to charge the plurality of battery packs in a first time period, so that the state of charge of each of the plurality of battery packs is any one of at least two states of charge, i.e., a first state of charge or a second state of charge, and the number of battery packs in each of the at least two states of charge is kept unchanged in the first time period, the first state of charge is 1, the second state of charge is less than the first state of charge, and the number of battery packs in each of the at least two states of charge is at least one; The power conversion circuit is used for charging the battery packs in the plurality of battery packs with a state of charge lower than the second state of charge to the second state of charge at a charging rate less than the charging rate at which the battery packs in the plurality of battery packs with a state of charge equal to the second state of charge are charged to the first state of charge.

2. The charging cabinet of claim 1, wherein, The power conversion circuit is also used for converting alternating current provided by the alternating current power grid into direct current to charge the plurality of battery packs when not in the first time period, so that the state of charge of the plurality of battery packs is the first state of charge.

3. The charging cabinet according to claim 1 or 2, characterized in that, The charging cabinet is particularly used for determining the number of battery packs in each of the at least two states of charge according to a predicted replacement number of battery packs.

4. The charging cabinet of claim 3, wherein, The charging cabinet further comprises a network interface used for connecting a server, and the charging cabinet obtains the predicted replacement number of battery packs through the server.

5. The charging cabinet of claim 3, wherein, The number of battery packs in the plurality of battery packs in the second state of charge is negatively correlated with the predicted replacement number of battery packs, and the number of battery packs in the plurality of battery packs in the first state of charge is positively correlated with the predicted replacement number of battery packs.

6. The charging cabinet of claim 5, wherein, The power conversion circuit is also used for adjusting the charging rate when charging the plurality of battery packs.

7. The charging cabinet of claim 6, wherein, The charging rate at which the power conversion circuit charges the battery packs in the plurality of battery packs with a state of charge lower than the second state of charge to the second state of charge is positively correlated with the predicted replacement number of battery packs, and the charging rate at which the power conversion circuit charges the battery packs in the plurality of battery packs with a state of charge equal to the second state of charge to the first state of charge is positively correlated with the predicted replacement number of battery packs.

8. The charging cabinet of claim 6, wherein, The power conversion circuit is used for charging the battery packs in the plurality of battery packs with a state of charge lower than the second state of charge to the second state of charge at a gradually decreasing charging rate, and charging the battery packs in the plurality of battery packs with a state of charge equal to the second state of charge to the first state of charge at a gradually decreasing charging rate.

9. The charging cabinet of claim 6, wherein, The power conversion circuit is configured to charge the battery packs with a state of charge lower than the second state of charge to the second state of charge at gradually increasing charge rates, and to charge the battery packs with the second state of charge to the first state of charge at gradually increasing charge rates.

10. The charging cabinet according to any one of claims 6-9, characterized in that, The charging cabinet further comprises a first controller: The first controller is configured to acquire detection information sent by the second controller of each of the battery packs, and to control the power conversion circuit according to the detection information, the detection information representing the state of charge of the corresponding battery pack.

11. The charging cabinet of claim 10, wherein, The first controller is further configured to determine the number of battery packs to be charged according to the state of charge of each of the battery packs and the number of battery packs in each of the at least two states of charge. The charge rate at which the power conversion circuit charges the battery packs with a state of charge lower than the second state of charge to the second state of charge is positively correlated with the number of battery packs to be charged, and the charge rate at which the power conversion circuit charges the battery packs with the second state of charge to the first state of charge is positively correlated with the number of battery packs to be charged.

12. The charging cabinet of claim 1, wherein, The at least two states of charge further comprises a third state of charge, the third state of charge being greater than the second state of charge and less than the first state of charge.

13. The charging cabinet of claim 10, wherein, The power conversion circuit comprises an alternating current / direct current conversion circuit and a plurality of direct current / direct current conversion circuits. An input end of the alternating current / direct current conversion circuit is an input end of the power conversion circuit, an output end of the alternating current / direct current conversion circuit is connected to an input end of the plurality of direct current / direct current conversion circuits, and an output end of each direct current / direct current conversion circuit in the plurality of direct current / direct current conversion circuits is configured to be connected to one of the plurality of output interfaces. Each direct current / direct current conversion circuit in the plurality of direct current / direct current conversion circuits is configured to output direct current after direct current conversion through the corresponding one of the plurality of output interfaces. The first controller is specifically configured to control the alternating current / direct current conversion circuit and the plurality of direct current / direct current conversion circuits according to the detection information, so as to adjust the charge rate when charging the plurality of battery packs.

14. The charging cabinet of claim 10, wherein, Each of the plurality of battery packs comprises a direct current / direct current conversion circuit and a second controller, and the power conversion circuit is an alternating current / direct current conversion circuit. An output end of the alternating current / direct current conversion circuit is configured to be connected to an input end of the direct current / direct current conversion circuit of each battery pack. The first controller is specifically configured to control the alternating current / direct current conversion circuit according to the detection information, and to send a control signal to the second controller of each battery pack, so that the second controller of each battery pack controls the corresponding direct current / direct current conversion circuit according to the control signal.

15. A battery pack, characterized by The battery pack is charged by the charging cabinet of any one of claims 1-14, and the battery pack comprises a DC / DC conversion circuit, a battery cell and a second controller; an input end of the DC / DC conversion circuit is configured to be connected to one of the plurality of output interfaces of the charging cabinet; the DC / DC conversion circuit is configured to charge the battery cell by converting the obtained DC power into DC power; the second controller is configured to send detection information representing a state of charge of the battery pack to the charging cabinet.

16. The battery pack of claim 15, wherein, The second controller is further configured to control the DC / DC conversion circuit to adjust a charging rate when charging the battery cell according to an obtained control signal, which is sent by the first controller of the charging cabinet.

17. A battery pack charging system, comprising: The battery pack charging system comprises the charging cabinet of any one of claims 1-14 and the battery pack of any one of claims 15-16, or the battery pack charging system comprises the battery pack and the charging cabinet of any one of claims 1-14.

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