A charging and swapping system

Abstract

The present application discloses a charging and swapping system, including an AC / DC conversion unit connected to a power grid, a switch unit connected to the AC / DC conversion unit, an energy storage battery connected to the switch unit, a variable unit, a DC / DC conversion unit, and a control unit. The variable unit can be loaded with a battery pack of an energy storage battery or a battery pack of a power battery, and the control unit is used to control the power grid to charge the energy storage battery and the variable unit during the valley power period, and to control the variable unit to charge the power battery during the non-valley power period, and to control the energy storage battery to charge the power battery after a preset period of time. Applied to this solution, the variable unit can be charged and discharged as an energy storage battery, and can also be charged as a power battery. Therefore, when the variable unit is used as an energy storage battery, the storage efficiency of the charging and swapping system when storing electricity is improved, thereby reducing the cost of the charging and swapping system and improving the flexibility 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 new energy electric vehicles mainly relies on the power of the power grid to charge the energy storage battery, and then the energy storage battery charges the new energy electric vehicle. When the energy storage battery cannot meet the charging needs of the new energy electric vehicle, the capacity of the energy storage battery needs to be expanded, so the entire energy storage battery of the charging and swapping system needs to be replaced, which increases the cost of the charging and swapping system.

[0004] It can be seen that how to reduce the cost 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 reduce the cost 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: an AC / DC conversion unit connected to a power grid, a switch unit connected to the AC / DC conversion unit, an energy storage battery connected to the switch unit, a variable unit, a DC / DC conversion unit and a control unit;

[0007] The control unit is used to control the switch unit to allow the power grid to charge the variable unit and the energy storage battery respectively through the AC / DC conversion unit in the case of a valley power period, and to control the switch unit to allow the variable unit to charge the power battery through the DC / DC conversion unit in the case of a non-valley power period, and after a delay of a preset time, control the energy storage battery to charge the power battery through the DC / DC conversion unit;

[0008] The AC / DC conversion unit is used to convert the alternating current output by the power grid into direct current that can meet the charging requirements of the energy storage battery and the variable unit when the power grid charges the energy storage battery and the variable unit respectively;

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

[0010] The variable unit may be loaded with the battery pack of the energy storage battery or the battery pack of the power battery to complete charging of the corresponding battery at different time periods;

[0011] When the energy storage battery does not meet the preset conditions, the switch unit is controlled to allow the power grid to charge the power battery and the variable unit respectively through the AC / DC conversion unit.

[0012] 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 AC / DC conversion unit to work and control the DC / DC conversion unit not to work when the power grid charges the energy storage battery and the variable unit respectively, and to control the AC / DC conversion unit not to work and control the DC / DC conversion unit to work when the energy storage battery or the variable unit charges the power battery.

[0013] Preferably, the switch unit includes a first switch group, a second switch group, a third switch group and a fourth switch group, the first end of the first switch group is connected to the output end of the AC / DC conversion unit, the second end of the first switch group is respectively connected to the first end of the second switch group, the input end of the DC / DC conversion unit, and the first end of the fourth switch group, the second end of the second switch group is connected to the energy storage battery, the first end of the third switch group is connected to the output end of the AC / DC conversion unit, the second end of the third switch group is connected to the variable unit, and the second end of the fourth switch group is connected to the power battery.

[0014] Preferably, there are multiple energy storage batteries, and there are multiple AC / DC conversion units, the first switch group, the second switch group, the third switch group, and the variable unit, which are connected to the energy storage batteries in a one-to-one correspondence;

[0015] The control unit is further used to control the switch unit to allow the power grid to charge the at least two energy storage batteries and the at least two variable units respectively through the corresponding AC / DC conversion unit during the off-peak period, and to control the switch unit and one variable unit to charge the power battery through the DC / DC conversion unit during the non-off-peak period, and after a delay of a preset time, control the corresponding energy storage battery to charge the power battery through the DC / DC conversion unit.

[0016] Preferably, the energy storage battery includes a plurality of battery packs, the second switch group includes a plurality of switches corresponding to each of the battery packs, the second end of each of the switches is connected to the corresponding battery pack, and the first end of each of the switches is connected to the second end of the first switch group and the DC / DC conversion unit after being connected to each other;

[0017] The control unit is further used to control one switch in the second switch group to be closed when the power grid charges the energy storage battery and the energy storage battery charges the power battery; and is further used to select a target battery pack in the energy storage battery that best matches the power battery according to preset parameters when the energy storage battery charges the power battery, and control the target battery pack in the energy storage battery to charge the power battery through the corresponding first switch group.

[0018] Preferably, when there are multiple energy storage batteries, the switch unit further includes a fifth switch group, the fifth switch groups are multiple and correspond one-to-one to the energy storage batteries, the first end of the fifth switch group is respectively connected to the second end of the corresponding first switch group and the first end of the corresponding second switch group, and the second end of the fifth switch group is respectively connected to the first end of the fourth switch group and the input end of the DC / DC conversion unit.

[0019] Preferably, the preset parameter is any combination of the voltage of the energy storage battery, the voltage of the power battery, the discharge current of the energy storage battery and the battery capacity of the energy storage battery.

[0020] Preferably, the preset condition is that the energy storage battery operates normally or the power of the energy storage battery meets the required power of the power battery.

[0021] Preferably, each switch in the second switch group is a bidirectionally conductive controllable switch.

[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 an AC / DC conversion unit connected to the power grid, a switch unit connected to the AC / DC conversion unit, an energy storage battery connected to the switch unit, a variable unit, a DC / DC conversion unit and a control unit. Among them, the variable unit can be loaded with a battery pack of an energy storage battery or a battery pack of a power battery to complete the charging of the corresponding battery at different time periods. The control unit is used to control the power grid to charge the energy storage battery and the variable unit respectively through the switch unit in the case of valley power time period, and to control the variable unit to charge the power battery through the switch unit in the case of non-valley power time period, and control the energy storage battery to charge the power battery after a preset period of time. Applied to this solution, the variable unit can be charged and discharged as an energy storage battery, and can also be charged as a power battery. Therefore, when the variable unit is used as an energy storage battery, the storage efficiency of the charging and swapping system when storing electricity is improved, thereby reducing the cost of the charging and swapping system. At the same time, the variable unit improves the flexibility of the charging and swapping system. In addition, since the control unit can control the energy storage battery to charge during the off-peak period and supply power to the power battery through the energy storage battery during the non-off-peak period, the charging and swapping system can choose to store the voltage of the power grid in the energy storage battery during the off-peak period, and supply power to the power battery during the non-off-peak period, thereby reducing the electricity cost of the charging and swapping system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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.

[0025] Figure 1 A circuit diagram of the first charging and swapping system provided in an embodiment of the present application;

[0026] Figure 2 A circuit diagram of a DC / DC conversion unit provided in an embodiment of the present application;

[0027] Figure 3 A circuit diagram of a second charging and swapping system provided in an embodiment of the present application;

[0028] Figure 4 A circuit diagram of the third charging and swapping system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] 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.

[0030] The core of this application is to provide a charging and swapping system to reduce electricity costs.

[0031] 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.

[0032] Figure 1 This is a circuit diagram of the first charging and swapping system provided in the embodiment of the present application. Figure 1 As shown, the system includes: an AC / DC conversion unit 10 connected to the power grid, a switch unit 11 connected to the AC / DC conversion unit 10, an energy storage battery 13 connected to the switch unit 11, a variable unit 14, a DC / DC conversion unit 12 and a control unit 16.

[0033] The control unit 16 is used to control the switch unit 11 to allow the power grid to charge the energy storage battery 13 and the variable unit 14 through the AC / DC conversion unit 10 during the off-peak period, and to control the switch unit 11 to allow the variable unit 14 to charge the power battery 15 through the DC / DC conversion unit 12 during the non-off-peak period, and after a preset delay, the energy storage battery 13 charges the power battery 15 through the DC / DC conversion unit 12.

[0034] The AC / DC conversion unit 10 is used to convert the output AC power of the power grid into DC power that can meet the charging requirements of the energy storage battery 13 and the variable unit 14 when the power grid is charging the energy storage battery 13 and the variable unit 14 respectively.

[0035] The DC / DC conversion unit 12 is used to convert the output DC power of the energy storage battery 13 or the variable unit 14 into DC power that can meet the charging demand of the power battery 15 when the energy storage battery 13 or the variable unit 14 is charging the power battery 15.

[0036] The variable unit 14 can be loaded with a battery pack of an energy storage battery or a battery pack of a power battery to complete charging of the corresponding batteries at different time periods.

[0037] 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.

[0038] In addition, the preset duration in the embodiment of the present application is specifically the time from the start of discharge to the completion of discharge of the variable unit 14, that is, the control unit 16 first controls the variable unit 14 to discharge to the power battery 15 through the switch unit 11 in the non-valley time period, and after the variable unit 14 is discharged, controls the energy storage battery 13 to discharge to the power battery 15 through the switch unit 11.

[0039] 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.

[0040] 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 variable unit 14 and / or the power battery 15 according to a charging curve with time as a variable.

[0041] 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).

[0042] 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 16 can also be connected to the AC / DC conversion unit 10 and the DC / DC conversion unit 12, and is used to control the AC / DC conversion unit 10 to work and the DC / DC conversion unit 12 not to work when the grid is connected to the energy storage battery 13 and the variable unit 14 respectively, and to control the AC / DC conversion unit 10 not to work and control the DC / DC conversion unit 12 to work when the energy storage battery 13 or the variable unit 14 is connected to the power battery 15.

[0043] like Figure 1As shown, the switch unit 11 includes a first switch group 20, a second switch group 21, a third switch group 22 and a fourth switch group 23. The first end of the first switch group 20 is connected to the output end of the AC / DC conversion unit 10, the second end of the first switch group 20 is respectively connected to the first end of the second switch group 21, the input end of the DC / DC conversion unit 12, and the first end of the fourth switch group 23, the second end of the second switch group 21 is connected to the energy storage battery 13, the first end of the third switch group 22 is connected to the output end of the AC / DC conversion unit 10, the second end of the third switch group 22 is connected to the variable unit 14, and the second end of the fourth switch group 23 is connected to the power battery 15.

[0044] In a specific implementation, the control unit 16 is used to control the AC / DC conversion unit 10 to start working, the first switch group 20, the second switch group 21 and the third switch group 22 to close, and the fourth switch group 23 to disconnect in the case of a valley power period, so as to ensure that the power grid charges the energy storage battery 13 and the variable unit 14; in the case of a non-valley power period, the control unit 16 is used to control the AC / DC conversion unit 10 to stop working, the first switch group 20 and the third switch group 22 to close, and the second switch group 21 and the fourth switch group 23 to disconnect, and after a delay of a preset time, control the first switch group 20, the third switch group 22 and the fourth switch group 23 to disconnect and the second switch group 21 to close, so as to ensure that the variable unit 14 discharges to the power battery 15 first, and after the variable unit 14 is discharged, the energy storage battery 13 discharges to the power battery 15.

[0045] It should also be noted that in order to ensure that the second switch group 21 can connect both the AC / DC conversion unit 10 and the energy storage battery 13, and the energy storage battery 13 and the DC / DC conversion unit 12, as a preferred embodiment, the switches in the second switch group 21 are all bidirectionally conductive controllable switches.

[0046] It can be understood that the switches included in the first switch group 20 , the third switch group 22 and the fourth switch group 23 may be bidirectionally conductive controllable switches or unidirectionally conductive controllable switches.

[0047] Figure 2 A circuit diagram of a DC / DC conversion unit provided in an embodiment of the present application. Figure 2As 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 first end of the fourth switch group 23, the second end of the first inductor L1 is respectively connected to the first end of the switch K1 and the first end of the switch K2, the second end of the switch K1 is grounded, the second end of the switch K2 is respectively 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 respectively connected to the power battery 15, the first end of the inductor C, and the second end of the fourth switch group 23, and the second end of the inductor C is grounded. In addition, in a specific implementation, the control unit 16 can also be connected to the third ends of the switch K1 and the switch K2 to control the opening and closing of the switch K1 and the switch K2.

[0048] It should be noted that 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.

[0049] The charging and swapping system provided in the embodiment of the present application includes an AC / DC conversion unit connected to the power grid, a switch unit connected to the AC / DC conversion unit, an energy storage battery connected to the switch unit, a variable unit, a DC / DC conversion unit and a control unit. Among them, the variable unit can be loaded with a battery pack of an energy storage battery or a battery pack of a power battery to complete the charging of the corresponding battery in different time periods. The control unit is used to control the power grid to charge the energy storage battery and the variable unit respectively through the switch unit in the case of valley power time period, and in the case of non-valley power time period, the variable unit is controlled by the switch unit to charge the power battery, and after a preset time, the energy storage battery is controlled to charge the power battery. Applied to this solution, the variable unit can be charged and discharged as an energy storage battery, and can also be charged as a power battery. Therefore, when the variable unit is used as an energy storage battery, the storage efficiency of the charging and swapping system when storing electricity is improved, thereby reducing the cost of the charging and swapping system. At the same time, the variable unit improves the flexibility 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 from the energy storage battery during the non-valley power period, thereby reducing the electricity cost of the charging and swapping system. In addition, since the variable unit is charged during the valley power period, the variable unit is equivalent to the energy storage battery during the valley power period, thereby improving the storage efficiency of the charging and swapping system when storing electricity.

[0050] Based on the above embodiment, the control unit 16 is also used to control the switch unit 11 to allow the power grid to charge the power battery 15 and the variable unit 14 respectively through the AC / DC conversion unit 10 when the energy storage battery 13 does not meet the preset conditions.

[0051] The preset condition is specifically that the energy storage battery 13 works normally or the power of the energy storage battery 13 meets the power requirement of the power battery 15 .

[0052] 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 16 can also control the switch unit 11 to allow the power grid to charge the power battery 15 through the AC / DC conversion unit 10 to ensure that the power battery 15 can be charged normally.

[0053] Figure 3 This is a circuit diagram of the second charging and swapping system provided in the embodiment of the present application. Figure 3 As shown, based on the above embodiment, there are multiple energy storage batteries 13, and there are multiple AC / DC conversion units 10, first switch group 20, second switch group 21, third switch group 22 and variable units 14, which are connected to the energy storage batteries 13 one by one.

[0054] The control unit 16 is also used to control the power grid to charge at least two energy storage batteries 13 and at least two variable units 14 through the corresponding AC / DC conversion unit 10 during the off-peak period through the switch unit 11, and to control a variable unit 14 to charge the power battery 15 through the DC / DC conversion unit 12 during the non-off-peak period through the switch unit 11, and after a preset delay, control the corresponding energy storage battery 13 to charge the power battery 15 through the DC / DC conversion unit 12.

[0055] In the embodiment of the present application, the preset duration is specifically the time from the start of discharge to the completion of discharge of the variable unit 14, that is, the control unit 16 first controls a variable unit 14 to discharge to the power battery 15 through the switch unit 11 in the non-valley time period, and after the variable unit 14 is discharged, controls the corresponding energy storage battery 13 to discharge to the power battery 15 through the switch unit 11.

[0056] In order to improve the working efficiency of the charging and swapping system, as a preferred embodiment, the control unit 16 is also used to select a target battery pack in the energy storage battery 13 that best matches the power battery 15 according to preset parameters when the energy storage battery 13 charges the power battery 15, and control the target battery pack in the 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.

[0057] It should be noted that the preset parameters are one or more of the voltage of the energy storage battery 13 , the voltage of the power battery 15 , the discharge current of the energy storage battery 13 , and the battery capacity of the energy storage battery 13 .

[0058] like Figure 3 As shown, based on the above embodiment, the energy storage battery 13 includes multiple battery packs, the switches in the second switch group 21 are multiple and correspond to each battery pack one by one, the second end of each switch is respectively connected to the corresponding battery pack, and the first end of each switch is connected to the second end of the first switch group 20 and the DC / DC conversion unit 12 after being connected to each other.

[0059] The control unit 16 is further used to control one switch in the second switch group 21 to be closed and the other switches to be open when the power grid is connected to the energy storage battery 13 and the energy storage battery 13 is connected to the power battery 15 .

[0060] Among them, the control unit 16 can control the opening and closing order of the switches in the second switch group 21 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.

[0061] It can be understood that, when the energy storage battery contains multiple battery packs, 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 improving the service life of the energy storage battery.

[0062] In order to further improve the working efficiency of the charging and swapping system, during the process of the energy storage battery 13 charging the power battery 15, the control unit 16 is also used to reselect the target battery pack in the 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.

[0063] It can be understood that, in the process of charging the power battery 15 from the energy storage battery 13, the power of the battery pack in 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 battery pack in 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 battery pack in the energy storage battery 13 does not reach the preset time, or that the voltage of the target battery pack in the energy storage battery 13 is not lower than the preset voltage.

[0064] like Figure 3As shown, in the case where there are multiple energy storage batteries 13, the control unit 16 also includes a fifth switch group 24, the number of the fifth switch groups 24 is multiple and corresponds one-to-one to the energy storage batteries 13, the first end of the fifth switch group 24 is respectively connected to the second end of the corresponding first switch group 20 and the first end of the corresponding second switch group 21, and the second end of the fifth switch group 24 is respectively connected to the first end of the fourth switch group 23 and the input end of the DC / DC conversion unit 12.

[0065] In a specific implementation, the fifth switch group 24 may be a diode, or a bidirectionally conductive controllable switch or a unidirectionally conductive controllable switch. When the fifth switch group 24 is a diode, the anode of the diode is connected to the corresponding AC / DC conversion unit, and the cathode of the diode is connected to the first end of the fourth switch group 23 and the input end of the DC / DC conversion unit 12 respectively.

[0066] In addition, when there are multiple energy storage batteries 13, AC / DC conversion units 10, first switch groups 20, second switch groups 21, third switch groups 22 and variable units 14, when the power grid charges the power battery 15 through the AC / DC conversion unit 10, the control unit 16 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, and 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 16 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.

[0067] The charging and swapping system provided in the embodiment of the present application has multiple energy storage batteries, thereby ensuring that when one energy storage battery malfunctions, the remaining energy storage batteries can continue to charge and discharge, thereby improving the stability of the charging and swapping system.

[0068] Figure 4 The circuit diagram of the third charging and swapping system provided in the embodiment of the present application. Figure 4 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 fourth switch group 23 is respectively connected to each power battery 15, the first end of each switch in the fourth switch group 23 is connected to the AC / DC conversion unit 10 after being connected to each other, and each DC / DC conversion unit 12 is connected in parallel with each switch in the fourth switch group 23.

[0069] In the embodiment of the present application, when the energy storage battery 13 or the variable unit 14 charges the power battery 15 through the DC / DC conversion unit 12, the control unit 16 can simultaneously control multiple fourth switch groups 23 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 16 only controls one fourth switch group 23 to be closed in the same time period.

[0070] It is understandable that, since the energy storage battery 13 can charge multiple power batteries 15 at the same time, the charging efficiency of the power battery 15 can be accelerated, and the speed at which the energy storage battery 13 supplies power to the multiple power batteries 15 is improved.

[0071] 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.

[0072] 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, It is characterized in that include: An AC / DC conversion unit connected to a power grid, a switch unit connected to the AC / DC conversion unit, an energy storage battery, a variable unit, a DC / DC conversion unit and a control unit connected to the switch unit; The control unit is used to control the switch unit to allow the power grid to charge the variable unit and the energy storage battery respectively through the AC / DC conversion unit in the case of a valley power period, and to control the switch unit to allow the variable unit to charge the power battery through the DC / DC conversion unit in the case of a non-valley power period, and after a delay of a preset time, control the energy storage battery to charge the power battery through the DC / DC conversion unit; The AC / DC conversion unit is used to convert the alternating current output by the power grid into direct current that can meet the charging requirements of the energy storage battery and the variable unit when the power grid charges the energy storage battery and the variable unit respectively; The DC / DC conversion unit is used to convert the output direct current of the energy storage battery or the variable unit into direct current that can meet the charging demand of the power battery when the energy storage battery or the variable unit charges the power battery; The variable unit may be loaded with the battery pack of the energy storage battery or the battery pack of the power battery to complete charging of the corresponding battery at different time periods; When the energy storage battery does not meet the preset conditions, the switch unit is controlled to allow the power grid to charge the power battery and the variable unit respectively through the AC / DC conversion unit; Wherein, the switch unit comprises a first switch group, a second switch group, a third switch group and a fourth switch group, a first end of the first switch group is connected to the output end of the AC / DC conversion unit, a second end of the first switch group is respectively connected to the first end of the second switch group, the input end of the DC / DC conversion unit, and the first end of the fourth switch group, a second end of the second switch group is connected to the energy storage battery, a first end of the third switch group is connected to the output end of the AC / DC conversion unit, a second end of the third switch group is connected to the variable unit, and a second end of the fourth switch group is connected to the power battery; The energy storage battery includes a plurality of battery packs, the second switch group includes a plurality of switches corresponding to each of the battery packs, the second end of each of the switches is connected to the corresponding battery pack, and the first end of each of the switches is connected to the second end of the first switch group and the DC / DC conversion unit after being connected to each other; The control unit is further used to control one switch in the second switch group to be closed when the power grid charges the energy storage battery and the energy storage battery charges the power battery; and is further used to select a target battery pack in the energy storage battery that best matches the power battery according to preset parameters when the energy storage battery charges the power battery, and control the target battery pack in the energy storage battery to charge the power battery through the corresponding first switch group.

2. The charging and swapping system according to claim 1, It is 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 AC / DC conversion unit to work and control the DC / DC conversion unit not to work when the power grid charges the energy storage battery and the variable unit respectively, and to control the AC / DC conversion unit not to work and control the DC / DC conversion unit to work when the energy storage battery or the variable unit charges the power battery.

3. The charging and swapping system according to claim 1, It is characterized in that There are multiple energy storage batteries, and there are multiple AC / DC conversion units, the first switch group, the second switch group, the third switch group, and the variable unit, which are connected to the energy storage batteries in a one-to-one correspondence.

4. The charging and swapping system according to claim 1, It is characterized in that In the case where there are multiple energy storage batteries, the switch unit further includes a fifth switch group, the fifth switch groups are multiple and correspond one-to-one to the energy storage batteries, the first end of the fifth switch group is respectively connected to the second end of the corresponding first switch group and the first end of the corresponding second switch group, and the second end of the fifth switch group is respectively connected to the first end of the fourth switch group and the input end of the DC / DC conversion unit.

5. The charging and swapping system according to claim 1, It is characterized in that The preset parameter is any combination of the voltage of the energy storage battery, the voltage of the power battery, the discharge current of the energy storage battery, and the battery capacity of the energy storage battery.

6. The charging and swapping system according to claim 2, It is characterized in that The preset condition is specifically that the energy storage battery operates normally or the power of the energy storage battery meets the required power of the power battery.

7. The charging and swapping system according to any one of claims 1, 3 or 4, It is characterized in that Each switch in the second switch group is a bidirectionally conductive controllable switch.

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

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