A charging and swapping system

Abstract

The present application discloses a charging and swapping system, including a plurality of AC / DC conversion units connected to a power grid, switch units connected to each of the AC / DC conversion units, diode groups connected to the switch units and the AC / DC conversion units in a one-to-one correspondence, and a plurality of energy storage batteries, DC / DC conversion units, and control units connected to the switch units, wherein the anodes of the diode groups are connected to the output ends of the AC / DC conversion units in a one-to-one correspondence, and the cathodes of the diode groups are connected to the switch units after being connected to each other. Since the anodes of the diode groups are connected to the output ends of the AC / DC conversion units in a one-to-one correspondence, it is ensured that when the power grid supplies power to the energy storage battery, the diodes connected to the AC / DC conversion units enable the AC / DC conversion units to charge only the energy storage batteries connected to them, thereby avoiding energy conversion between different energy storage battery groups and improving the service life of the charging and swapping system.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a charging and swapping system. Background Art

[0002] With the development of science and technology, new energy electric vehicles, as a model of clean energy use, have gradually become the focus of automobile industry and energy development, and have gradually become a more important part of human daily life.

[0003] At present, the charging and swapping system for powering new energy electric vehicles mainly connects multiple energy storage battery packs through an AC / DC conversion unit, so that the power of the power grid can charge multiple energy storage battery packs at the same time. However, since the power grid charges multiple energy storage battery packs through an AC / DC conversion unit at the same time, there is a problem of energy conversion between energy storage battery packs, which reduces the service life of the charging and swapping system.

[0004] It can be seen that how to improve the service life of the charging and swapping system is an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0005] The purpose of this application is to provide a charging and swapping system to increase the service life of the charging and swapping system.

[0006] In order to solve the above technical problems, the present application provides a charging and swapping system, comprising: a plurality of AC / DC conversion units connected to a power grid, switch units respectively connected to each of the AC / DC conversion units, a diode group connected to the switch unit and the AC / DC conversion unit in a one-to-one correspondence, and a plurality of energy storage batteries, DC / DC conversion units and control units respectively connected to the switch unit;

[0007] The control unit is used to control the switch unit to allow the power grid to charge at least two of the energy storage batteries simultaneously through the AC / DC conversion unit in the case of a valley power period, and to control the switch unit to allow the energy storage battery to charge the power battery through the corresponding DC / DC conversion unit in the case of a non-valley power period;

[0008] The AC / DC conversion unit is used to convert the AC power output by the power grid into DC power that can meet the charging requirements of each of the energy storage batteries when the power grid is charging at least two of the energy storage batteries at the same time;

[0009] The DC / DC conversion unit is used to convert the output direct current of each energy storage battery into input direct current that can meet the charging demand of the power battery when the energy storage battery charges the power battery;

[0010] The anodes of the diode groups are connected to the output ends of the AC / DC conversion units one by one, respectively, and the cathodes of the diode groups are connected to each other and then connected to the switch unit.

[0011] Preferably, the control unit is also connected to each of the AC / DC conversion units and the DC / DC conversion unit, and is used to control the corresponding AC / DC conversion unit to work and control the DC / DC conversion unit not to work when the power grid is connected to the energy storage battery, and to control the DC / DC conversion unit to work and control each of the AC / DC conversion units not to work when the energy storage battery is charging the power battery;

[0012] The control unit is further configured to control the power grid to charge the power battery through the corresponding AC / DC conversion unit through the switch unit when none of the energy storage batteries meets the preset conditions;

[0013] The preset condition specifically is that at least one of the energy storage batteries operates normally or the power of at least one of the energy storage batteries meets the required power of the power battery.

[0014] Preferably, the switch unit includes a plurality of first switch groups and a second switch group, the first end of each of the first switch groups is connected to each of the AC / DC conversion units, the second end of each of the first switch groups is connected to each of the energy storage batteries, and the second switch groups are connected to the input and output ends of the DC / DC conversion units.

[0015] Preferably, each of the energy storage batteries includes a plurality of battery packs, and the corresponding first switch group includes a plurality of switches corresponding to each of the battery packs one by one, and the second end of each of the switches is respectively connected to each of the battery packs, and the first end of each of the switches is connected to the corresponding AC / DC conversion unit and the DC / DC conversion unit after being connected to each other;

[0016] The control unit is further used for controlling that at any time, only one switch in the corresponding first switch group is closed when the power grid charges the energy storage battery and the energy storage battery charges the power battery; and is further used for selecting a battery pack in a target energy storage battery that best matches the power battery according to preset parameters when the energy storage battery charges the power battery, and controlling the target battery pack in the energy storage battery to charge the power battery through the corresponding first switch group.

[0017] Preferably, the preset parameters are one or more of the voltage of the battery pack in each of the energy storage batteries, the voltage of the power battery, the discharge current of the battery pack in each of the energy storage batteries, and the battery capacity of each of the energy storage batteries.

[0018] Preferably, the second switch group is specifically a unidirectional controllable switch.

[0019] Preferably, when the switch unit controls the power grid to charge the power battery through the corresponding AC / DC conversion unit, the control unit is further used to control the AC / DC conversion unit to work in time periods.

[0020] Preferably, when the switching unit controls the power grid to charge the power battery through the corresponding AC / DC conversion unit, the control unit is also used to control at least two of the AC / DC conversion units to operate simultaneously, wherein the total output current value of the AC / DC conversion units operating simultaneously meets the charging demand of the power battery.

[0021] Preferably, the charging requirement of the energy storage battery and / or the power battery is specifically a voltage or current output according to time changes.

[0022] Preferably, the charging requirement of the energy storage battery and / or the power battery is specifically to output voltage and current according to the charging parameters required by the BMS.

[0023] The charging and swapping system provided in the present application includes a plurality of AC / DC conversion units connected to the power grid, switch units connected to each AC / DC conversion unit, a diode group connected one-to-one with the switch unit and the AC / DC conversion unit, and a plurality of energy storage batteries, DC / DC conversion units and control units connected to the switch unit. The anodes of the diode groups are connected one-to-one with the output ends of the AC / DC conversion units, the cathodes of the diode groups are connected to the switch units after being connected to each other, and the control unit is used to control the power grid to supply power to at least two of the energy storage batteries through the switch units during the valley power period, and to control at least two energy storage batteries to supply power to the power battery through the switch units during the non-valley power period. Since the anodes of the diode groups are connected one-to-one with the output ends of the AC / DC conversion units, it is ensured that when the power grid supplies power to the energy storage battery, the diodes corresponding to the AC / DC conversion units enable the AC / DC conversion units to charge only the energy storage batteries corresponding to them, thereby avoiding energy conversion between different energy storage battery groups and improving the service life of the charging and swapping system. In addition, since the control unit can control the energy storage battery to charge during the valley power period and supply power to the power battery through the energy storage battery during the non-valley power period, the charging and swapping system can choose to store the voltage of the power grid in the energy storage battery during the valley power period, and supply power to the energy storage battery during the non-valley power period, thereby reducing the electricity cost of the charging and swapping system. In addition, since multiple groups of energy storage batteries are set up to charge and discharge at the same time, the charging efficiency of the energy storage battery and the power battery is accelerated, and it is also ensured that when a certain energy storage battery works abnormally, the remaining energy storage batteries can continue to charge and discharge, thereby improving the stability of the charging and swapping system.

[0024] In the traditional electric vehicle energy storage charging and swapping system, all the energy of the power grid passes through the AC / DC conversion unit to the busbar. Therefore, the AC / DC conversion unit becomes the bottleneck of system reliability. Once damaged, the system cannot work. However, this application is a distributed system, that is, the power grid is powered by the AC / DC conversion unit, and the energy storage device can also be powered. The damage of any unit does not affect the normal operation of other units. This solution is more reliable.

[0025] In the prior art, although energy storage equipment is provided, it has the following disadvantages: the energy of the power grid needs to be converted by AC / DC and then by DC / DC before reaching the energy storage battery. When the energy storage battery is discharged, it needs to undergo two DC / DC conversions to provide the stored energy to the battery that needs to be charged. The energy is converted three times, and the charging efficiency is low. In this application, the power grid energy can be converted by AC / DC to charge the energy storage battery, and the energy storage battery can be converted by DC / DC once more to charge the battery replacement battery or electric vehicle power battery, which helps to improve the system efficiency.

[0026] Compared with the existing technology, each rechargeable battery unit can save a set of DC / DC circuits, which is lower in cost.

[0027] In this application, a common AC / DC is used for charging the energy storage battery, and the system cost is further reduced.

[0028] In traditional energy storage charging and swapping systems, when the energy storage battery pack is charging or discharging, all battery packs are connected in parallel, and it is necessary to ensure that all batteries in the battery pack have the same voltage, which is very expensive to maintain. In this application, the batteries do not need to be connected in parallel, so there is no need to screen the batteries, and the requirements for battery use (especially when the energy storage battery uses retired electric vehicle batteries) are greatly reduced. At the same time, a multi-channel energy storage system is added, and the energy storage efficiency is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A circuit diagram of a charging and swapping system provided in an embodiment of the present application;

[0031] Figure 2 A circuit diagram of a DC / DC conversion unit provided in an embodiment of the present application;

[0032] Figure 3 A circuit diagram of another charging and swapping system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] The core of this application is to provide a charging and swapping system to reduce electricity costs.

[0035] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0036] Figure 1 A circuit diagram of a charging and swapping system provided in an embodiment of the present application. Figure 1As shown, the system includes: a plurality of AC / DC conversion units 10 connected to a power grid, switch units 11 respectively connected to each of the AC / DC conversion units 10, diode groups 16 connected to the switch units 11 and the AC / DC conversion units 10 in a one-to-one correspondence, a plurality of energy storage batteries 13, DC / DC conversion units 12 and a control unit 14 connected to the switch units 11.

[0037] The control unit 14 is used to control the switch unit 11 to allow the power grid to charge part or all of the energy storage battery 13 through the AC / DC conversion unit 10 during the off-peak period, and to control the switch unit 11 to allow part or all of the energy storage battery 13 to charge the power battery 15 through the corresponding DC / DC conversion unit 12 during the non-off-peak period.

[0038] The AC / DC conversion unit 10 is used to convert the output alternating current of the power grid into direct current that can meet the charging requirements of each energy storage battery 13 when the power grid is charging the energy storage battery 13 .

[0039] The DC / DC conversion unit 12 is used to convert the output DC power of each energy storage battery 13 into DC power that can meet the charging demand of the power battery 15 when the energy storage battery 13 charges the power battery 15 .

[0040] The anodes of the diode groups 16 are connected to the output terminals of the AC / DC conversion units 10 in a one-to-one correspondence, and the cathodes of the diode groups 16 are connected to each other and then connected to the switch unit 11 .

[0041] In the embodiment of the present application, the off-peak time period is the off-peak time period stipulated by the municipality, and the non-off-peak time period is the non-off-peak time period stipulated by the municipality. It is understandable that when the municipal regulations change, the off-peak time period and the non-off-peak time period may change accordingly.

[0042] It should be noted that in a battery swap station, the power battery 15 refers to a battery that is quickly replaced for an electric vehicle; in a charging station, the power battery 15 refers to a battery in an electric vehicle. In addition, the energy storage battery 13 can be a brand new battery purchased separately, or it can be a power battery 15 retired from an electric vehicle.

[0043] In order to prevent the AC / DC conversion unit 10 and the DC / DC conversion unit 12 from working continuously, resulting in unnecessary consumption of the grid input voltage, and at the same time to prevent the grid from supplying power to the power battery 15 when the energy storage battery 13 supplies power to the power battery 15, in a specific implementation, the control unit 14 can also be connected to each AC / DC conversion unit 10 and the DC / DC conversion unit 12, and is used to control the corresponding AC / DC conversion unit 10 to work and control the DC / DC conversion unit 12 not to work when the grid charges part or all of the energy storage batteries 13, and to control the DC / DC conversion unit 12 to work and control each AC / DC conversion unit 10 not to work when all or part of the energy storage batteries 13 charge the power battery 15.

[0044] like Figure 1 As shown, the switch unit 11 includes a plurality of first switch groups 20 and second switch groups 21, the first end of each first switch group 20 is connected to each AC / DC conversion unit 10, the second end of each first switch group 20 is connected to each energy storage battery 13, and the second switch groups 21 are connected to the power grid and the power battery 15.

[0045] In a specific implementation, the control unit 14 is used to control the corresponding AC / DC conversion unit 10 to start working, the first switch group 20 to close, and the second switch group 21 to disconnect during a valley power period, thereby ensuring that the power grid charges at least two energy storage batteries 13; in a non-valley power period, the control unit 14 is used to control the corresponding AC / DC conversion unit 10 to stop working, the first switch group 20 to close, and the second switch group 21 to disconnect, thereby ensuring that at least two energy storage batteries 13 supply power to the power battery 15 through the DC / DC conversion unit 12.

[0046] It should also be noted that in order to ensure that the first switch group 20 can connect the corresponding AC / DC conversion unit 10 and the corresponding energy storage battery 13, and can also connect the corresponding energy storage battery 13 and the DC / DC conversion unit 12, as a preferred embodiment, the switches in the first switch group 20 are all bidirectionally conductive controllable switches.

[0047] It is understandable that the switches included in the second switch group 21 can be bidirectional controllable switches or unidirectional controllable switches. In a specific implementation, the switches of the second switch group 21 are unidirectional controllable switches.

[0048] In a specific implementation, the AC / DC conversion unit 10 converts the input signal of the power grid into an input signal of the energy storage battery 13 and / or the power battery 15 that meets the requirements of the battery management system (BMS).

[0049] Figure 2A circuit diagram of a DC / DC conversion unit provided in an embodiment of the present application. Figure 2 As shown, the DC / DC conversion unit 12 includes a first inductor L1, a second inductor L2, a switch K1, a switch K2, a capacitor C, and a diode D1. The first end of the first inductor L1 is connected to the AC / DC conversion unit 10 and the first end of the second switch group 21, respectively, the second end of the first inductor L1 is connected to the first end of the switch K1 and the first end of the switch K2, respectively, the second end of the switch K1 is grounded, the second end of the switch K2 is connected to the first end of the second inductor L2 and the cathode of the diode D1, the anode of the diode D1 is grounded, the second end of the second inductor L2 is connected to the power battery 15, the first end of the capacitor C, and the second end of the second switch group 21, and the second end of the capacitor C is grounded. In addition, in a specific implementation, the control unit 14 can also be connected to the third end of the switch K1 and the switch K2 to control the opening and closing of the switch K1 and the switch K2.

[0050] Understandably, Figure 2 The circuit diagram is a DC / DC conversion unit 12 provided based on a buck-boost circuit. The DC / DC conversion unit 12 may also be a separate boost circuit or a separate buck circuit.

[0051] The charging and swapping system provided in the embodiment of the present application includes a plurality of AC / DC conversion units connected to the power grid, a switch unit connected to each AC / DC conversion unit, a diode group connected to the switch unit and the AC / DC conversion unit in a one-to-one correspondence, and a plurality of energy storage battery DC / DC conversion units connected to the switch unit and a control unit. Among them, the anodes of the diode groups are connected to the output ends of the AC / DC conversion units in a one-to-one correspondence, the cathodes of the diode groups are connected to the switch unit after being connected to each other, and the control unit is used to control the power grid to supply power to at least two of the energy storage batteries through the switch unit in the case of valley power time period, and to control at least two energy storage batteries to supply power to the power battery through the switch unit in the case of non-valley power time period. Since the anodes of the diode groups are connected to the output ends of the AC / DC conversion units in a one-to-one correspondence, it is ensured that when the power grid supplies power to the energy storage battery, the diodes corresponding to the AC / DC conversion units enable the AC / DC conversion units to charge only the energy storage batteries corresponding to them, thereby avoiding energy conversion between different energy storage battery groups and improving the service life of the charging and swapping system. In addition, since the control unit can control the energy storage battery to charge during the valley power period and supply power to the power battery through the energy storage battery during the non-valley power period, the charging and swapping system can choose to store the voltage of the power grid in the energy storage battery during the valley power period, and supply power to the energy storage battery during the non-valley power period, thereby reducing the electricity cost of the charging and swapping system. In addition, since multiple groups of energy storage batteries are set up to charge and discharge at the same time, the charging efficiency of the energy storage battery and the power battery is accelerated, and it is also ensured that when a certain energy storage battery works abnormally, the remaining energy storage batteries can continue to charge and discharge, thereby improving the stability of the charging and swapping system.

[0052] In the traditional electric vehicle energy storage charging and swapping system, all the energy of the power grid passes through the AC / DC conversion unit to the busbar. Therefore, the AC / DC conversion unit becomes the bottleneck of system reliability. Once damaged, the system cannot work. However, this application is a distributed system, that is, the power grid is powered by the AC / DC conversion unit, and the energy storage device can also be powered. The damage of any unit does not affect the normal operation of other units. This solution is more reliable.

[0053] In the prior art, although energy storage equipment is provided, it has the following disadvantages: the energy of the power grid needs to be converted by AC / DC and then by DC / DC before reaching the energy storage battery. When the energy storage battery is discharged, it needs to undergo two DC / DC conversions to provide the stored energy to the battery that needs to be charged. The energy is converted three times, and the charging efficiency is low. In this application, the power grid energy can be converted by AC / DC to charge the energy storage battery, and the energy storage battery can be converted by DC / DC once more to charge the battery replacement battery or electric vehicle power battery, which helps to improve the system efficiency.

[0054] Compared with the existing technology, each rechargeable battery unit can save a set of DC / DC circuits, which is lower in cost.

[0055] In this application, a common AC / DC is used for charging the energy storage battery, and the system cost is further reduced.

[0056] In traditional energy storage charging and swapping systems, when the energy storage battery pack is charging or discharging, all battery packs are connected in parallel, and it is necessary to ensure that all batteries in the battery pack have the same voltage, which is very expensive to maintain. In this application, the batteries do not need to be connected in parallel, so there is no need to screen the batteries, and the requirements for battery use (especially when the energy storage battery uses retired electric vehicle batteries) are greatly reduced. At the same time, a multi-channel energy storage system is added, and the energy storage efficiency is further improved.

[0057] On the basis of the above embodiment, the control unit 14 is also used to control the grid to be connected to the power battery 15 through the corresponding AC / DC conversion unit 10 through the switch unit 11 when none of the energy storage batteries 13 meets the preset conditions.

[0058] The preset condition is specifically that at least one of the energy storage batteries 13 operates normally or the power of at least one of the energy storage batteries 13 meets the power requirement of the power battery 15 .

[0059] It should be noted that when the power grid charges the power battery 15 through the AC / DC conversion unit 10, the control unit 14 can control each AC / DC conversion unit 10 to work in segments, that is, at the same time, only one AC / DC conversion unit 10 is controlled to work. After the working time of the AC / DC conversion unit 10 reaches a preset time, one of the remaining AC / DC conversion units 10 is selected to work. The control unit 14 can also control at least two AC / DC conversion units 10 to work at the same time, and the output current of the working AC / DC conversion unit 10 comprehensively meets the charging requirements of the power battery 15 group.

[0060] It is understandable that when the power of the energy storage battery 13 cannot meet the demand for charging the power battery 15, or the energy storage battery 13 is malfunctioning, the control unit 14 can also control the power grid through the AC / DC conversion unit 10 through the switch unit 11 to charge the power battery 15 to ensure that the power battery 15 can be charged normally, thereby ensuring the user's usage experience.

[0061] On the basis of the above embodiment, the energy storage battery 13 includes multiple groups of battery packs, and the corresponding first switch group 20 includes multiple switches corresponding to each battery pack one by one. The second end of each switch is respectively connected to each battery pack, and the first end of each switch is connected to the corresponding AC / DC conversion unit 10 and DC / DC conversion unit 12 after being connected to each other.

[0062] The control unit 14 is also used to control one switch in the corresponding first switch group 20 to be closed and the other switches to be open when the power grid charges at least two energy storage batteries 13 and the energy storage battery 13 charges the power battery 15.

[0063] Among them, the control unit 14 can control the opening and closing order of the switches in the first switch group 20 according to a preset rule, for example, controlling the corresponding switches to be closed or opened according to the order of the battery packs in the energy storage battery 13, that is, first controlling the switch corresponding to the battery pack numbered 1 to be closed and the remaining switches to be opened, then controlling the switch corresponding to the battery pack numbered 2 to be closed and the remaining switches to be opened, and so on.

[0064] In order to improve the working efficiency of the charging and swapping system, as a preferred embodiment, the control unit 14 is also used to select the battery pack in the target energy storage battery 13 that best matches the power battery 15 according to preset parameters when the energy storage battery 13 and the power battery 15 are being charged, and control the target energy storage battery 13 to charge the power battery 15 through the switch in the switch unit 11 corresponding to the target battery pack in the energy storage battery 13.

[0065] It should be noted that the preset parameters are any combination of the voltage of each energy storage battery 13 , the voltage of the power battery 15 , the discharge current of each energy storage battery 13 , and the battery capacity of each energy storage battery 13 .

[0066] In addition, in order to further improve the working efficiency of the charging and swapping system, in the process of at least two energy storage batteries 13 charging the power battery 15, the control unit 14 is also used to reselect the target energy storage battery 13 that best matches the power battery 15 according to preset parameters when the target energy storage battery 13 does not meet the preset requirements.

[0067] It can be understood that, in the process of at least two energy storage batteries 13 charging the power battery 15, the power level of the target energy storage battery 13 is monitored according to a preset period or in real time to see whether it meets the preset requirements. Once it does not meet the preset requirements, the energy storage battery 13 that best matches the power battery 15 can be reselected. In a specific implementation, the preset requirement can be that the discharge time of the target energy storage battery 13 does not reach the preset time, or that the voltage of the target energy storage battery 13 is not lower than the preset voltage.

[0068] In the charging and swapping system provided in the embodiment of the present application, when there are multiple energy storage batteries, the control unit only controls the closure of the switch corresponding to one battery pack in the energy storage battery at the same time, thereby preventing the battery packs in the same energy storage battery from being directly connected in parallel and causing current circulation, thereby increasing the service life of the energy storage battery.

[0069] Figure 3 A circuit diagram of another charging and swapping system provided in an embodiment of the present application. Figure 3 As shown, on the basis of the above embodiment, the number of power batteries 15 is n (where n is a positive integer), wherein the number of DC / DC conversion units 12 matches the number of power batteries 15, the second end of each switch in the second switch group 21 is respectively connected to each power battery 15, the first end of each switch in the second switch group 21 is connected to the diode group 16 after being connected to each other, and each DC / DC conversion unit 12 is connected in parallel with each switch in the second switch group 21.

[0070] In the embodiment of the present application, when the energy storage battery 13 charges the power battery 15 through the DC / DC conversion unit 12, the control unit 14 can simultaneously control the switches in the second switch group 21 to be closed, so as to realize simultaneous charging of multiple power batteries 15; when the power grid charges the power battery 15 through the AC / DC conversion unit 10, only one power battery 15 is charged in the same time period, that is, the control unit 14 only controls one switch in the second switch group 21 to be closed in the same time period.

[0071] It is understandable that, since the energy storage battery 13 can charge a plurality of power batteries 15 at the same time, the charging speed of the power battery 15 can be accelerated, thereby increasing the speed at which the energy storage battery 13 supplies power to the power battery 15 .

[0072] The above is a detailed introduction to a charging and swapping system provided by the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can refer to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0073] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A charging and swapping system, characterized in that: include: A plurality of AC / DC conversion units connected to a power grid, switch units connected to the AC / DC conversion units respectively, diode groups connected to the switch units and the AC / DC conversion units in a one-to-one correspondence, and a plurality of energy storage batteries, DC / DC conversion units and control units respectively connected to the switch units; The control unit is used to control the switch unit to allow the power grid to charge at least two of the energy storage batteries simultaneously through the AC / DC conversion unit in the case of a valley power period, and to control the switch unit to allow the energy storage battery to charge the power battery through the corresponding DC / DC conversion unit in the case of a non-valley power period; The AC / DC conversion unit is used to convert the AC power output by the power grid into DC power that can meet the charging requirements of each of the energy storage batteries when the power grid is charging at least two of the energy storage batteries at the same time; The DC / DC conversion unit is used to convert the output direct current of each energy storage battery into input direct current that can meet the charging demand of the power battery when the energy storage battery charges the power battery; The switch unit includes a plurality of first switch groups and a second switch group, wherein the first end of each of the first switch groups is connected to each of the AC / DC conversion units, and the second end of each of the first switch groups is connected to each of the energy storage batteries; the diode group is connected between the first switch group and the second switch group; The anode of each diode in the diode group is respectively connected to the output end of the AC / DC conversion unit and the output end of a corresponding group of energy storage battery groups, and the cathodes of the diode groups are connected to each other and then connected to the second switch group.

2. The charging and swapping system according to claim 1, characterized in that: The control unit is also connected to each of the AC / DC conversion units and the DC / DC conversion unit, and is used to control the corresponding AC / DC conversion unit to work and control the DC / DC conversion unit not to work when the power grid is connected to the energy storage battery, and to control the DC / DC conversion unit to work and control each of the AC / DC conversion units not to work when the energy storage battery is charging the power battery; The control unit is further configured to control the power grid to charge the power battery through the corresponding AC / DC conversion unit through the switch unit when none of the energy storage batteries meets the preset conditions; The preset condition specifically is that at least one of the energy storage batteries operates normally or the power of at least one of the energy storage batteries meets the required power of the power battery.

3. The charging and swapping system according to claim 1, characterized in that: The second switch group is connected to the input terminal and the output terminal of the DC / DC conversion unit respectively.

4. The charging and swapping system according to claim 3, characterized in that: Each of the energy storage batteries includes a plurality of battery packs, and the corresponding first switch group includes a plurality of switches corresponding to each of the battery packs one by one, and the second end of each of the switches is connected to each of the battery packs respectively, and the first end of each of the switches is connected to the corresponding AC / DC conversion unit and the DC / DC conversion unit after being connected to each other; The control unit is further used for controlling that at any time, only one switch in the corresponding first switch group is closed when the power grid charges the energy storage battery and the energy storage battery charges the power battery; and is further used for selecting a battery pack in a target energy storage battery that best matches the power battery according to preset parameters when the energy storage battery charges the power battery, and controlling the target battery pack in the energy storage battery to charge the power battery through the corresponding first switch group.

5. The charging and swapping system according to claim 4, characterized in that: The preset parameters are one or more of the voltage of the battery pack in each of the energy storage batteries, the voltage of the power battery, the discharge current of the battery pack in each of the energy storage batteries, and the battery capacity of each of the energy storage batteries.

6. The charging and swapping system according to claim 3, characterized in that: The second switch group is specifically a unidirectional controllable switch.

7. The charging and swapping system according to claim 2, characterized in that: In the case where the switch unit controls the power grid to charge the power battery through the corresponding AC / DC conversion unit, the control unit is further used to control the AC / DC conversion unit to work in time periods.

8. The charging and swapping system according to claim 2, characterized in that: In the case where the switching unit controls the power grid to charge the power battery through the corresponding AC / DC conversion unit, the control unit is further used to control at least two of the AC / DC conversion units to operate simultaneously, wherein the total output current value of the AC / DC conversion units operating simultaneously meets the charging demand of the power battery.

9. The charging and swapping system according to claim 1, characterized in that: The charging requirement of the energy storage battery and / or the power battery is specifically a voltage or current output according to time changes.

10. The charging and swapping system according to claim 1, characterized in that: The charging requirement of the energy storage battery and / or the power battery is specifically to output voltage and current according to the charging parameters required by the BMS.

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