CN214874279U

CN214874279U - Charging and battery replacing system

Info

Publication number: CN214874279U
Application number: CN202120797809.7U
Authority: CN
Inventors: 张华建
Original assignee: Zhejiang Ying Fei Amperex Technology Ltd; Inventronics Hangzhou Co Ltd
Current assignee: Zhejiang Ying Fei Amperex Technology Ltd; Inventronics Hangzhou Co Ltd
Priority date: 2021-04-19
Filing date: 2021-04-19
Publication date: 2021-11-26
Anticipated expiration: 2031-04-19

Abstract

The application discloses fill and trade electric system, including a plurality of AC/DC conversion units that are connected with the electric wire netting, the switch unit who is connected with each AC/DC conversion unit respectively, the diode group of being connected with switch unit and AC/DC conversion unit one-to-one, and the multiunit energy storage battery, DC/DC conversion unit and the control unit of being connected with the switch unit, wherein the positive pole of diode group is connected with the output one-to-one of AC/DC conversion unit respectively, the negative pole interconnect back of diode group is connected with the switch unit. Because the anodes of the diode groups are respectively connected with the output ends of the AC/DC conversion units in a one-to-one correspondence manner, when the power grid supplies power to the energy storage batteries, the diodes correspondingly connected with the AC/DC conversion units ensure that the AC/DC conversion units only charge the energy storage batteries correspondingly connected with the AC/DC conversion units, thereby avoiding energy conversion among different energy storage battery groups and prolonging the service life of the charging and replacing system.

Description

Charging and battery replacing system

Technical Field

The application relates to the technical field of power electronics, in particular to a battery charging and replacing system.

Background

With the development of science and technology, new energy electric vehicles are becoming the key points of the automobile industry and energy development gradually as a model for the use of clean energy, and also becoming more important components in human daily life gradually.

At present, a charging and replacing system for supplying power to a new energy electric vehicle is mainly connected with a plurality of energy storage battery packs through an AC/DC conversion unit, so that electric energy of a power grid charges the plurality of energy storage battery packs simultaneously. And because in the process that the power grid charges a plurality of energy storage battery packs through one AC/DC conversion unit, the problem of energy conversion among the energy storage battery packs exists, thereby reducing the service life of the charging and replacing system.

Therefore, how to improve the service life of the battery charging and replacing system is a problem to be solved urgently by those skilled in the art.

SUMMERY OF THE UTILITY MODEL

The application aims to provide a battery charging and replacing system for prolonging the service life of the battery charging and replacing system.

In order to solve the above technical problem, the present application provides a charging and battery replacing system, including: the system comprises a plurality of AC/DC conversion units connected with a power grid, switch units respectively connected with the AC/DC conversion units, diode groups in one-to-one correspondence with the switch units and the AC/DC conversion units, a plurality of groups of energy storage batteries respectively connected with the switch units, a DC/DC conversion unit and a control unit;

the control unit is used for controlling the switch unit to enable a power grid to charge at least two energy storage batteries simultaneously through the AC/DC conversion unit in the valley power time period, and controlling the switch unit to enable the energy storage batteries to charge power batteries through the corresponding DC/DC conversion unit in the off-valley power time period;

the AC/DC conversion unit is used for converting alternating current output by a power grid into direct current capable of meeting the charging requirements of the energy storage batteries under the condition that the power grid charges at least two energy storage batteries simultaneously;

the DC/DC conversion unit is used for converting the output direct current of each energy storage battery into the input direct current capable of meeting the charging requirement of the power battery under the condition that the energy storage battery charges the power battery;

anodes of the diode groups are respectively connected with output ends of the AC/DC conversion units in a one-to-one correspondence mode, and cathodes of the diode groups are connected with the switch unit after being connected with each other.

Preferably, the control unit is further connected to each of the AC/DC conversion units and the DC/DC conversion unit, and is configured to control the corresponding AC/DC conversion unit to operate and control the DC/DC conversion unit to not operate when the power grid is connected to the energy storage battery, and control the DC/DC conversion unit to operate and control each of the AC/DC conversion units to not operate when the energy storage battery is used to charge the power battery;

the control unit is further used for controlling a power grid to charge the power battery through the corresponding AC/DC conversion unit through the switch unit under the condition that each energy storage battery does not meet a preset condition;

the preset condition is that at least one energy storage battery works normally or the electric quantity of at least one energy storage battery meets the required electric quantity of the power battery.

Preferably, the switch unit includes a plurality of first switch groups and second switch groups, a first end of each first switch group is correspondingly connected to each AC/DC conversion unit, a second end of each first switch group is correspondingly connected to each energy storage battery, and the second switch groups are respectively connected to an input end and an output end of the DC/DC conversion unit.

Preferably, each energy storage battery includes a plurality of groups of battery packs, a plurality of switches in the corresponding first switch group correspond to the battery packs one by one, second ends of the switches are respectively connected to the battery packs correspondingly, and first ends of the switches are connected to corresponding AC/DC conversion units and DC/DC conversion units after being connected to each other;

the control unit is further configured to control only one switch in the corresponding first switch group to be closed at any time under the condition that the power grid charges the energy storage battery and the energy storage battery charges the power battery; and the power battery charging control circuit is also used for selecting a battery pack in a target energy storage battery which is most matched with the power battery according to preset parameters under the condition that 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.

Preferably, the preset parameter is one or more of a voltage of a battery pack in each energy storage battery, a voltage of the power battery, a discharge current of the battery pack in each energy storage battery, and a battery capacity of each energy storage battery.

Preferably, the second switch group is a unidirectional controllable switch.

Preferably, the control unit is further configured to control the AC/DC conversion unit to operate in different periods when the switching unit controls the power grid to charge the power battery through the corresponding AC/DC conversion unit.

Preferably, when the power battery is charged by the power grid through the corresponding AC/DC conversion units under the control of the switch unit, the control unit is further configured to control at least two of the AC/DC conversion units to operate simultaneously, where the total output current value of the AC/DC conversion units operating simultaneously meets the charging requirement of the power battery.

Preferably, the charging requirement of the energy storage battery and/or the power battery is specifically a voltage or a current which is output according to time variation.

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

The charging and replacing system comprises a plurality of AC/DC conversion units connected with a power grid, switch units respectively connected with the AC/DC conversion units, diode groups connected with the switch units and the AC/DC conversion units in a one-to-one correspondence manner, and a plurality of groups of energy storage batteries, DC/DC conversion units and control units connected with the switch units. The control unit is used for controlling the power grid to supply power to at least two energy storage batteries through the switch unit under the condition of valley electricity time periods, and controlling the at least two energy storage batteries to supply power to the power battery through the switch unit under the condition of non-valley electricity time periods. Because the anodes of the diode groups are respectively connected with the output ends of the AC/DC conversion units in a one-to-one correspondence manner, when the power grid supplies power to the energy storage batteries, the diodes correspondingly connected with the AC/DC conversion units ensure that the AC/DC conversion units only charge the energy storage batteries correspondingly connected with the AC/DC conversion units, thereby avoiding energy conversion among different energy storage battery groups and prolonging the service life of the charging and replacing system. In addition, the control unit can control the energy storage battery to charge in the valley power time period and supply power to the power battery through the energy storage battery in the off-valley power time period, so that the charging and replacing system can store the voltage of a power grid into the energy storage battery in the valley power time period and supply power through the energy storage battery in the off-valley power time period, and the power consumption cost of the charging and replacing system is reduced. In addition, because the plurality of groups of energy storage batteries are arranged for charging and discharging simultaneously, the charging efficiency of the energy storage batteries and the power battery is accelerated, the remaining energy storage batteries can continue to be charged and discharged when a certain energy storage battery works abnormally, and the stability of a charging and replacing system is improved.

In the traditional electric vehicle energy storage charging and replacing system, all energy of a power grid is transferred to a bus through an AC/DC conversion unit, so that the AC/DC conversion unit becomes the bottleneck of system reliability, and once the system is damaged, the system cannot work. The system is a distributed system, namely a power grid supplies power through the AC/DC conversion unit, the energy storage device can supply power, the damage of any unit does not influence the normal work of other units, and the reliability of the scheme is higher.

In the prior art, although an energy storage device is provided, the following disadvantages are provided: the energy of the power grid is converted into the energy storage battery through AC/DC conversion, and the energy of the power grid is supplied to the battery to be charged through DC/DC conversion twice when the energy storage battery is discharged; the energy is converted for three times, and the charging efficiency is low. The energy of the power grid can be charged into the energy storage battery through AC/DC conversion, and the energy storage battery can be charged into a battery replacement battery or a power battery of the electric vehicle through DC/DC conversion once, so that the system efficiency is improved.

Compared with the prior art, each rechargeable battery unit can save one set of DC/DC circuit, and the cost is lower.

The AC/DC charging device and the charging method share the AC/DC for charging the energy storage battery, and the system cost is further reduced.

In a traditional energy storage charging and battery replacing system, when energy storage battery packs are charged or discharged, all the battery packs are connected in parallel, the voltage of all the batteries in the battery packs needs to be ensured to be the same, and the maintenance cost is high. And the batteries need not be connected in parallel in this application, so do not need to carry out the battery screening, to the use of battery (especially when the energy storage battery uses the battery of the electric automobile of retirement), require greatly reduced. And meanwhile, a multi-path energy storage system is added, and the electric energy storage efficiency is further improved.

Drawings

In order to more clearly illustrate the embodiments of the present application, the drawings needed for the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained by those skilled in the art without inventive effort.

Fig. 1 is a circuit diagram of a battery charging and swapping system according to an embodiment of the present disclosure;

fig. 2 is a circuit diagram of a DC/DC conversion unit according to an embodiment of the present disclosure;

fig. 3 is a circuit diagram of another battery charging and replacing system according to an embodiment of the present application

The reference numbers are as follows:

the system comprises an AC/DC conversion unit 10, a control unit 11, a DC/DC conversion unit 12, an energy storage battery 13, a control unit 14, a power battery 15, a diode group 16, a first switch group 20 and a second switch group 21.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without any creative effort belong to the protection scope of the present application.

The core of the application is to provide a charging and battery replacing system for reducing the power consumption cost.

In order that those skilled in the art will better understand the disclosure, the following detailed description will be given with reference to the accompanying drawings.

Fig. 1 is a circuit diagram of a battery charging and swapping system according to an embodiment of the present application. As shown in fig. 1, the system includes: the system comprises a plurality of AC/DC conversion units 10 connected with a power grid, a switch unit 11 connected with each AC/DC conversion unit 10, diode groups 16 connected with the switch units 11 and the AC/DC conversion units 10 in a one-to-one correspondence mode, and a plurality of groups of energy storage batteries 13, DC/DC conversion units 12 and control units 14 connected with the switch units 11.

And the control unit 14 is used for controlling the switch unit 11 to charge the power grid to part or all of the energy storage batteries 13 through the AC/DC conversion unit 10 in the case of valley power time periods, and controlling the switch unit 11 to charge part or all of the energy storage batteries 13 to the power batteries 15 through the corresponding DC/DC conversion unit 12 in the case of non-valley power time periods.

And the AC/DC conversion unit 10 is used for converting the output alternating current of the power grid into direct current capable of meeting the charging requirement of each energy storage battery 13 under the condition that the energy storage batteries 13 are charged by the power grid.

The DC/DC conversion unit 12 is configured to convert the output direct current of each energy storage battery 13 into a direct current capable of meeting the charging requirement of the power battery 15 when the energy storage battery 13 charges the power battery 15.

Anodes of the diode groups 16 are respectively connected to the output terminals of the AC/DC conversion unit 10 in a one-to-one correspondence, and cathodes of the diode groups 16 are connected to the switching unit 11 after being connected to each other.

In the embodiment of the application, the valley power time period is a municipal specified valley power time period, and the non-valley power time period is a municipal specified non-valley power time period. It will be appreciated that the off-valley and off-valley periods may vary as municipality regulations change.

It should be noted that, in the battery replacement station, the power battery 15 is a battery replacement battery for quickly replacing the electric vehicle; in the charging station, the power battery 15 refers to a battery in an electric vehicle. In addition, the energy storage battery 13 may be a completely new battery purchased separately, or may be a power battery 15 for the decommissioning of the electric vehicle.

In order to prevent the AC/DC conversion unit 10 and the DC/DC conversion unit 12 from continuously operating and causing unnecessary consumption of the input voltage of the power grid, and to prevent the power 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 may be further connected to each of the AC/DC conversion unit 10 and the DC/DC conversion unit 12, and configured to control the corresponding AC/DC conversion unit 10 to operate and control the DC/DC conversion unit 12 not to operate when the power grid charges part or all of the energy storage batteries 13, and control the DC/DC conversion unit 12 to operate and control each of the AC/DC conversion units 10 not to operate when all or part of the energy storage batteries 13 charge the power battery 15.

As shown in fig. 1, the switch unit 11 includes a plurality of first switch groups 20 and second switch groups 21, a first end of each first switch group 20 is correspondingly connected to each AC/DC conversion unit 10, a second end of each first switch group 20 is correspondingly connected to each energy storage battery 13, and each second switch group 21 is respectively connected to the grid and the power battery 15.

In a specific implementation, the control unit 14 is configured to, in a valley-power time period, control the corresponding AC/DC conversion unit 10 to start operating, the first switch group 20 to be closed, and the second switch group 21 to be opened, so as to ensure that the power grid charges the at least two energy storage batteries 13, and in a non-valley-power time period, control the corresponding AC/DC conversion unit 10 to stop operating, the first switch group 20 to be closed, and the second switch group 21 to be opened, so as to ensure that the at least two energy storage batteries 13 supply power to the power battery 15 through the DC/DC conversion unit 12.

It should be noted that, in order to ensure that the first switch group 20 can communicate both the corresponding AC/DC conversion unit 10 and the corresponding energy storage battery 13, and communicate 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 controllable switches that are bidirectionally conductive.

It is understood that the switches included in the second switch group 21 may be controllable switches that are conducted in both directions, or may be controllable switches that are conducted in one direction. In a specific implementation, the switches of the second switch group 21 are controllable switches conducting in a single direction.

In a specific implementation, the AC/DC conversion unit 10 is configured to convert an input signal of a power grid into an input signal of the energy storage Battery 13 and/or the power Battery 15 meeting a requirement of a Battery Management System (BMS).

Fig. 2 is a circuit diagram of a DC/DC conversion unit according to an embodiment of the present disclosure. As shown in fig. 2, 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, 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, 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 practical implementation, the control unit 14 may be further connected to third terminals of the switches K1 and K2 to control opening and closing of the switches K1 and K2.

It is to be understood that fig. 2 is a circuit diagram of a DC/DC converting unit 12 provided on the basis of a step-up/step-down circuit, and the DC/DC converting unit 12 may also be a separate step-up circuit or a separate step-down circuit.

The charging and switching system provided by the embodiment of the application comprises a plurality of AC/DC conversion units connected with a power grid, switch units respectively connected with the AC/DC conversion units, diode groups connected with the switch units and the AC/DC conversion units in a one-to-one correspondence manner, a plurality of groups of energy storage battery DC/DC conversion units connected with the switch units, and a control unit. The control unit is used for controlling the power grid to supply power to at least two energy storage batteries through the switch unit under the condition of valley electricity time periods, and controlling the at least two energy storage batteries to supply power to the power battery through the switch unit under the condition of non-valley electricity time periods. Because the anodes of the diode groups are respectively connected with the output ends of the AC/DC conversion units in a one-to-one correspondence manner, when the power grid supplies power to the energy storage batteries, the diodes correspondingly connected with the AC/DC conversion units ensure that the AC/DC conversion units only charge the energy storage batteries correspondingly connected with the AC/DC conversion units, thereby avoiding energy conversion among different energy storage battery groups and prolonging the service life of the charging and replacing system. In addition, the control unit can control the energy storage battery to charge in the valley power time period and supply power to the power battery through the energy storage battery in the off-valley power time period, so that the charging and replacing system can store the voltage of a power grid into the energy storage battery in the valley power time period and supply power through the energy storage battery in the off-valley power time period, and the power consumption cost of the charging and replacing system is reduced. In addition, because the plurality of groups of energy storage batteries are arranged for charging and discharging simultaneously, the charging efficiency of the energy storage batteries and the power battery is accelerated, the remaining energy storage batteries can continue to be charged and discharged when a certain energy storage battery works abnormally, and the stability of a charging and replacing system is improved.

On the basis of the above embodiment, the control unit 14 is further configured to control, through the switch unit 11, the power grid to be connected to the power battery 15 through the corresponding AC/DC conversion unit 10 in a case that none of the energy storage batteries 13 satisfies the preset condition.

The preset condition is specifically that at least one energy storage battery 13 works normally or the electric quantity of at least one energy storage battery 13 meets the required electric quantity of the power battery 15.

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 may control each AC/DC conversion unit 10 to operate in a segmented manner, that is, at the same time, to control one AC/DC conversion unit 10 to operate, after the operating time of the AC/DC conversion unit 10 reaches a preset time period, one AC/DC conversion unit 10 is selected from the remaining AC/DC conversion units 10 to operate, the control unit 14 may also control at least two AC/DC conversion units 10 to operate simultaneously, and the output current of the AC/DC conversion unit 10 in operation comprehensively meets the charging requirement of the power battery 15 group.

It can be understood that, when the electric quantity of the energy storage battery 13 cannot meet the requirement for charging the power battery 15, or when the energy storage battery 13 works abnormally, the control unit 14 may also control the power grid to charge the power battery 15 through the AC/DC conversion unit 10 by the switch unit 11, so as to ensure that the power battery 15 can be normally charged, thereby ensuring that the user experiences the use experience.

On the basis of the above embodiment, the energy storage battery 13 includes a plurality of battery packs, the corresponding first switch group 20 includes a plurality of switches and corresponds to each battery pack one by one, the second ends of the switches are respectively connected to each battery pack, and the first ends of the switches are connected to the corresponding AC/DC conversion unit 10 and the DC/DC conversion unit 12 after being connected to each other.

The control unit 14 is further configured to control one switch in the corresponding first switch group 20 to be closed and the remaining switches to be in an open state when the power grid charges the at least two energy storage batteries 13 and the energy storage batteries 13 charge the power battery 15.

The control unit 14 may control the switching sequence of the switches in the first switch group 20 according to a preset rule, for example, control the corresponding switches to be turned on or turned off according to the sequence of the battery packs in the energy storage battery 13, that is, first control the switch corresponding to the battery pack with the number 1 to be turned on and the other switches to be turned off, then control the switch corresponding to the battery pack with the number 2 to be turned on and the other switches to be turned off, and so on.

In order to improve the working efficiency of the charging and replacing system, as a preferred embodiment, the control unit 14 is further configured to, when the energy storage battery 13 and the power battery 15 are charged, select a battery pack in the target energy storage battery 13 that most matches the power battery 15 according to preset parameters, and control the target energy storage battery 13 to charge the power battery 15 through a switch in the switch unit 11 that corresponds to the target battery pack in the energy storage battery 13.

The preset parameter is any combination of the voltage of each energy storage cell 13, the voltage of the power cell 15, the discharge current of each energy storage cell 13, and the battery capacity of each energy storage cell 13.

In addition, in order to further improve the working efficiency of the charging and replacing system, in the process of charging the power battery 15 by the at least two energy storage batteries 13, the control unit 14 is further configured to select the target energy storage battery 13 that is most matched with the power battery 15 again according to the preset parameters when the target energy storage battery 13 does not meet the preset requirements.

It can be understood that, in the process of charging the power battery 15 by at least two energy storage batteries 13, whether the electric quantity of the target energy storage battery 13 meets the preset requirement is monitored according to a preset period or in real time, once the preset requirement is not met, the energy storage battery 13 most matched with the power battery 15 can be reselected, and in specific implementation, the preset requirement may 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.

According to the charging and replacing system provided by the embodiment of the application, under the condition that the number of the energy storage batteries is multiple, the control unit only controls the switch corresponding to one battery pack in the energy storage batteries to be closed at the same time, so that the current circulation caused by the direct parallel connection of the battery packs in the same energy storage battery can be prevented, and the service life of the energy storage batteries is prolonged.

Fig. 3 is a circuit diagram of another battery charging and replacing system according to an embodiment of the present application. As shown in fig. 3, in addition to the above embodiment, the number of the power batteries 15 is n (where n is a positive integer), where the number of the DC/DC conversion units 12 matches the number of the power batteries 15, the second ends of the switches in the second switch group 21 are respectively connected to the power batteries 15, the first ends of the switches in the second switch group 21 are connected to the diode group 16 after being connected to each other, and the DC/DC conversion units 12 are connected in parallel to the switches in the second switch group 21.

In the embodiment of the present application, when the energy storage battery 13 charges the power batteries 15 through the DC/DC conversion unit 12, the control unit 14 may simultaneously control the switches in the second switch group 21 to be closed, so as to simultaneously charge the plurality of power batteries 15; when the power grid charges the power batteries 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 controls only one switch in the second switch group 21 to be closed in the same time period.

It can be understood that, because the energy storage battery 13 can charge a plurality of power batteries 15 at the same time, the charging speed of the power batteries 15 can be increased, and the speed of supplying power to the power batteries 15 by the energy storage battery 13 is increased.

The above provides a detailed description of a charging and battery replacing system provided by the present application. The embodiments are described in a progressive manner in the specification, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. It should be noted that, for those skilled in the art, it is possible to make several improvements and modifications to the present application without departing from the principle of the present application, and such improvements and modifications also fall within the scope of the claims of the present application.

It is further noted that, in the present specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Claims

1. A charging and battery replacing system, comprising: the system comprises a plurality of AC/DC conversion units connected with a power grid, switch units respectively connected with the AC/DC conversion units, diode groups in one-to-one correspondence with the switch units and the AC/DC conversion units, a plurality of groups of energy storage batteries respectively connected with the switch units, a DC/DC conversion unit and a control unit;

2. The battery charging and replacing system according to claim 1, wherein the control unit is further connected to each of the AC/DC conversion units and the DC/DC conversion unit, and configured to control the corresponding AC/DC conversion unit to operate and control the DC/DC conversion unit to not operate when a power grid is connected to the energy storage battery, and control the DC/DC conversion unit to operate and control each of the AC/DC conversion units to not operate when the energy storage battery is charging the power battery;

3. The battery charging and replacing system according to claim 1, wherein the switch unit includes a plurality of first switch groups and second switch groups, a first end of each first switch group is correspondingly connected to each AC/DC conversion unit, a second end of each first switch group is correspondingly connected to each energy storage battery, and the second switch groups are respectively connected to an input end and an output end of the DC/DC conversion unit.

4. The battery charging and replacing system according to claim 3, wherein each of the energy storage batteries comprises a plurality of sets of battery packs, a plurality of switches in the corresponding first switch set correspond to the battery packs one by one, second ends of the switches are respectively connected to the battery packs correspondingly, and first ends of the switches are connected to the corresponding AC/DC conversion unit and the corresponding DC/DC conversion unit after being connected to each other;

5. The charging and replacing system as claimed in claim 4, wherein the preset parameter is one or more of a voltage of a battery pack in each of the energy storage batteries, a voltage of the power battery, a discharge current of a battery pack in each of the energy storage batteries, and a battery capacity of each of the energy storage batteries.

6. The battery charging and replacing system as claimed in claim 3, wherein the second switch group is a unidirectional controllable switch.

7. The charging and replacing system as claimed in claim 2, wherein the control unit is further configured to control the AC/DC conversion units to operate in different time periods when the switch unit controls a power grid to charge the power battery through the corresponding AC/DC conversion unit.

8. The charging and replacing system as claimed in claim 2, wherein the control unit is further configured to control at least two AC/DC conversion units to operate simultaneously when the switch unit controls a power grid to charge the power battery through the corresponding AC/DC conversion unit, wherein a total output current value of the AC/DC conversion units operating simultaneously satisfies a charging requirement of the power battery.

9. The charging and replacing system as claimed in claim 1, wherein the charging requirement of the energy storage battery and/or the power battery is a voltage or a current outputted according to a time variation.

10. The charging and replacing system as claimed in claim 1, wherein the charging requirements of the energy storage battery and/or the power battery are output voltage and current according to the charging parameters required by the BMS.