Electric vehicle charging and discharging system with new and old batteries mixed and control method thereof

Abstract

The application discloses a new and old battery mixed electric vehicle charging and discharging system and a control method thereof. The system comprises at least two batteries, an energy management system, a first charging interface, a first discharging interface, a second charging interface and a second discharging interface corresponding to the batteries, wherein the at least two batteries comprise at least one new battery and at least one old battery; the first charging interface is used for connecting a charging pile; the first discharging interface is used for connecting a vehicle end load; each second discharging interface is connected with the first discharging interface; a battery charging end is connected with the second charging interface; a battery discharging end is connected with the second discharging interface; and the energy management system is used for controlling the second charging interface corresponding to the first battery to be in communication with the first charging interface in a charging mode, and controlling the voltage output by the third battery to the first discharging interface to be equal to that of the second battery and then to be boosted at the end of the discharging of the second battery in a discharging mode, so that the new and old batteries are mixed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power battery utilization, and particularly relates to a new and old battery mixed electric vehicle charging and discharging system and a control method thereof. BACKGROUND

[0002] With the increasing application of batteries, the number of waste batteries increases rapidly. Recycling and reusing old batteries can not only alleviate resource shortages, but also reduce environmental pollution. At the same time, for electric vehicles and other devices that require long-range endurance, using old battery packs to increase the range has important practical significance.

[0003] For the use of old batteries, the conventional method in the industry is usually to disassemble the battery pack, such as disassembling to the module level for electric tricycles; or further disassembling to the battery cell level for recombination and reuse; or finally disassembling into anode materials and cathode materials for recycling and reuse, and there is no case of directly applying the battery without disassembling. SUMMARY

[0004] The present application provides a new and old battery mixed electric vehicle charging and discharging system and a control method thereof, to realize the mixed use of new and old batteries.

[0005] According to an aspect of the present application, a new and old battery mixed electric vehicle charging and discharging system is provided, comprising:

[0006] A hybrid battery pack comprising at least two batteries, the at least two batteries comprising at least one new battery and at least one old battery;

[0007] A first charging interface for connecting to a charging pile;

[0008] A first discharging interface for connecting to a vehicle end load;

[0009] A set of charging and discharging interfaces corresponding to each of the batteries; the set of charging and discharging interfaces comprises a second charging interface and a second discharging interface, each of the second discharging interfaces is connected to the first discharging interface; for any of the batteries, a battery charging end of the battery is connected to a second charging interface corresponding to the battery, and a battery discharging end of the battery is connected to a second discharging interface corresponding to the battery;

[0010] The energy management system is configured to control the second charging interface corresponding to the first battery to be in communication with the first charging interface in a charging mode, the first battery being any battery in the hybrid battery pack; and the energy management system is further configured to control the third battery to output the same voltage as the second battery to the first discharging interface when the remaining capacity of the second battery reaches a first preset remaining capacity in a discharging mode, and to raise the voltage output by the third battery to the first discharging interface after the third battery discharges for a first preset time length; wherein the second battery and the third battery are different batteries.

[0011] Optionally, the new and old battery mixed electric vehicle charging and discharging system further comprises a charging control switch corresponding to each battery.

[0012] For any charging control switch, the first end of the charging control switch is connected to the second charging interface corresponding to the battery corresponding to the charging control switch, and the second end of the charging control switch is connected to the first charging interface.

[0013] The energy management system is connected to the control end of each charging control switch, and the energy management system is configured to control the charging control switch corresponding to the first battery to be closed in the charging mode to charge the first battery, the energy management system is further configured to communicate with the charging control module of the charging pile during the charging of the first battery, and output a synchronization signal in real time, the energy management system is further configured to stop outputting the synchronization signal when the remaining capacity of the first battery reaches a second preset remaining capacity, and control the charging control switch corresponding to the first battery to be opened, control the charging control switch corresponding to the fourth battery to be closed, so that the charging control module initiates a handshake request to the hybrid battery pack again, so that the charging control module performs a handshake operation with the fourth battery and charges the fourth battery; the fourth battery being any battery in the hybrid battery pack except the first battery in the charging mode.

[0014] Optionally, the new and old battery mixed electric vehicle charging and discharging system further comprises a voltage conversion module corresponding to each of the batteries, for any voltage conversion module, a first end of the voltage conversion module is connected with a second discharging interface corresponding to the battery corresponding to the voltage conversion module, a second end of the voltage conversion module is connected with the first discharging interface, the energy management system is connected with a control end of each voltage conversion module, the energy management system is used to control the voltage conversion module corresponding to the third battery to output the same voltage as the second battery when the remaining capacity of the second battery reaches the first preset remaining capacity in the discharging mode, and is further used to lift the voltage output by the voltage conversion module corresponding to the third battery after the third battery is discharged for the first preset time length.

[0015] Optionally, the new and old battery mixed electric vehicle charging and discharging system further comprises an anti-backflow module corresponding to each of the batteries, for any anti-backflow module, a first end of the anti-backflow module is connected with a second discharging interface corresponding to the battery corresponding to the anti-backflow module, a second end of the anti-backflow module is connected with the first discharging interface.

[0016] According to another aspect of the present application, a control method of a new and old battery mixed electric vehicle charging and discharging system is provided, which is applied to the new and old battery mixed electric vehicle charging and discharging system of any one of the above aspects.

[0017] The control method of the new and old battery mixed electric vehicle charging and discharging system comprises:

[0018] In the charging mode, the energy management system controls the second charging interface corresponding to the first battery to communicate with the first charging interface, so that the charging pile charges the first battery; wherein the first battery is any battery in the mixed battery pack.

[0019] In the discharging mode, the energy management system controls the third battery to output the same voltage as the second battery to the first discharging interface when the remaining capacity of the second battery reaches the first preset remaining capacity.

[0020] The energy management system lifts the voltage output by the third battery to the first discharging interface after the third battery is discharged for the first preset time length; wherein the second battery and the third battery are different batteries.

[0021] Optionally, the charging pile comprises a charging control module, each of the batteries comprises a battery management module; the electric vehicle charging and discharging system with mixed new and old batteries further comprises a charging control switch corresponding to each of the batteries; for any charging control switch, a first end of the charging control switch is connected with the second charging interface corresponding to the charging control switch, and a second end of the charging control switch is connected with the first charging interface;

[0022] The energy management system controls the second charging interface corresponding to the first battery to be in communication with the first charging interface, so that the charging pile charges the first battery, which comprises:

[0023] The energy management system controls the charging control switch corresponding to the first battery to be closed, so that the second charging interface corresponding to the first battery is in communication with the first charging interface;

[0024] The charging control module initiates a handshake request to the mixed battery pack, so as to perform a handshake operation with the first battery;

[0025] The battery management module of the first battery transmits charging parameters of the first battery to the charging control module;

[0026] The charging control module outputs an electric signal to the first battery according to the charging parameters corresponding to the first battery, so as to charge the first battery; wherein the charging parameters at least include the size of the charging current.

[0027] Optionally, after the charging control module outputs an electric signal to the first battery according to the charging parameters corresponding to the first battery, it further comprises:

[0028] The energy management system outputs a synchronization signal to the charging control module in real time;

[0029] When the remaining capacity of the first battery reaches a second preset remaining capacity, the energy management system stops outputting the synchronization signal, controls the charging control switch corresponding to the first battery to be closed, and controls the charging control switch corresponding to the fourth battery to be closed; the fourth battery is any battery in the mixed battery pack in the charging mode except the first battery;

[0030] When the charging control module does not receive the synchronization signal, it reinitiates a handshake request to the mixed battery pack, so as to perform a handshake operation with the fourth battery;

[0031] The battery management module of the fourth battery transmits charging parameters corresponding to the fourth battery to the charging control module;

[0032] The charging control module outputs an electric signal to the fourth battery according to the charging parameter corresponding to the fourth battery, so as to charge the fourth battery.

[0033] Optionally, the energy management system controls the second charging interfaces to be sequentially communicated with the first charging interface in the order of the remaining capacities of the batteries in the hybrid battery pack from large to small, so that the charging pile sequentially charges the batteries in the order of the remaining capacities of the batteries from large to small.

[0034] Optionally, the electric vehicle charging and discharging system further comprises a voltage conversion module corresponding to each battery, for any voltage conversion module, a first end of the voltage conversion module is connected with a second discharging interface corresponding to the battery corresponding to the voltage conversion module, a second end of the voltage conversion module is connected with the first discharging interface, and a control end of each voltage conversion module is connected with the energy management system.

[0035] The energy management system controls the third battery to output the same voltage as the second battery to the first discharging interface when the remaining capacity of the second battery reaches the first preset remaining capacity, and the energy management system controls a discharging circuit in the third battery to be closed to enable the third battery to output a voltage to the second discharging interface connected with the third battery.

[0036] The energy management system controls a discharging circuit in the third battery to be closed to enable the third battery to output a voltage to the second discharging interface connected with the third battery when the remaining capacity of the second battery reaches the first preset remaining capacity.

[0037] The energy management system controls the voltage conversion module corresponding to the third battery to output the same voltage as the second battery.

[0038] The energy management system raises the voltage output by the third battery to the first discharging interface after the third battery is discharged for a first preset time length.

[0039] The energy management system raises the voltage output by the voltage conversion module corresponding to the third battery after the third battery is discharged for a first preset time length.

[0040] Optionally, the energy management system further comprises the following after raising the voltage output by the third battery to the first discharging interface after the third battery is discharged for a first preset time length.

[0041] The energy management system controls the second battery to stop discharging after the second preset time length after raising the voltage output by the third battery to the first discharging interface.

[0042] The technical scheme of the embodiment of the application sets the old battery on the electric vehicle, and configures the old battery with a corresponding second charging interface and a second discharging interface, so as to control the old battery to charge in a charging mode and to discharge in a discharging mode through the energy management system, and then to provide electric energy for the electric vehicle together with the new battery, thereby realizing the secondary use of the retired battery and saving cost. Meanwhile, in the discharging mode, the voltage output by the third battery to the first discharging interface is first equal to the voltage output by the second battery to the first discharging interface and then is raised to be greater than the voltage output by the second battery to the first discharging interface, so that the third battery smoothly enters the discharging mode, and the third battery is always loaded after being connected, thereby avoiding the voltage fluctuation caused by the alternate loading of the third battery and the second battery and ensuring the stability of the battery discharge in the discharging mode.

[0043] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the application, nor is it used to limit the scope of the application. Other features of the application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0045] Figure 1 A structural schematic diagram of a new-old battery mixed electric vehicle charging and discharging system provided by the embodiment of the application;

[0046] Figure 2 A structural schematic diagram of another new-old battery mixed electric vehicle charging and discharging system provided by the embodiment of the application;

[0047] Figure 3 A flowchart of a control method of a new-old battery mixed electric vehicle charging and discharging system provided by the embodiment of the application;

[0048] Figure 4 A flowchart of another control method of a new-old battery mixed electric vehicle charging and discharging system provided by the embodiment of the application;

[0049] Figure 5 A flowchart of still another control method of a new-old battery mixed electric vehicle charging and discharging system provided by the embodiment of the application. DETAILED DESCRIPTION

[0050] In order to make the person skilled in the art better understand the technical scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor should fall within the scope of protection of the present application.

[0051] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0052] Figure 1 A structural schematic diagram of a new-old battery mixed electric vehicle charging and discharging system is provided for the embodiments of the present application, referring to Figure 1 The new-old battery mixed electric vehicle charging and discharging system comprises:

[0053] The mixed battery pack 10 comprises at least two batteries, and the at least two batteries comprise at least one new battery 101 and at least one old battery 102;

[0054] The first charging interface 12 is used to access the charging pile 15;

[0055] The first discharging interface 13 is used to access the vehicle end load 16;

[0056] The charging and discharging interface group corresponding to each battery comprises a second charging interface 141 and a second discharging interface 142, and each second discharging interface 142 is connected with the first discharging interface 13; the charging and discharging interface group is arranged in correspondence with the battery, specifically, the charging and discharging interface group corresponds to the battery one by one, one battery corresponds to one charging and discharging interface group, and different batteries correspond to different charging and discharging interface groups. The charging and discharging interface group comprises a second charging interface 141 and a second discharging interface 142, specifically, each charging and discharging interface group comprises one second charging interface 141 and one second discharging interface 142, and the second charging interfaces 141 included in different charging and discharging interface groups are different, and the second discharging interfaces 142 included in different charging and discharging interface groups are different.

[0057] Each battery includes a battery charging end A and a battery discharging end B. For any battery, the battery charging end A of the battery is connected to the second charging interface 141 corresponding to the battery, and the battery discharging end B of the battery is connected to the second discharging interface 142 corresponding to the battery.

[0058] The energy management system 11 is configured to control the second charging interface corresponding to the first battery to be in communication with the first charging interface in a charging mode, where the first battery is any battery in the hybrid battery pack 10, specifically any battery in the hybrid battery pack 10 in the charging mode.

[0059] The energy management system 11 is further configured to control the third battery to output the same voltage as the second battery to the first discharging interface 13 when the remaining capacity of the second battery reaches a first preset remaining capacity in a discharging mode, specifically to control the third battery to output a voltage equal to the first preset voltage to the first discharging interface 13, and to raise the voltage output by the third battery to the first discharging interface 13 after the third battery discharges for a first preset duration, where the raised voltage is a second preset voltage. The second battery and the third battery are different batteries, the second battery is the battery currently discharging in the discharging mode, and the third battery is any battery other than the battery currently discharging. The first preset voltage is equal to the voltage output by the second battery to the first discharging interface 13 when the remaining capacity of the second battery reaches the first preset remaining capacity, and the second preset voltage is greater than the first preset voltage.

[0060] The hybrid battery pack 10 includes at least one new battery 101 and at least one old battery 102. In this embodiment, one new battery 101 and one old battery 102 are included, where the new battery 101 is a battery that has not been used since it was manufactured, and the old battery 102 can be a retired battery, such as a battery removed from another device. The charge-discharge interface group is in one-to-one correspondence with the batteries, that is, one battery corresponds to one second charging interface 141 and one second discharging interface 142. The battery charging end A of each battery is connected to the second charging interface 141 corresponding to each battery, and the battery discharging end B of each battery is connected to the second discharging interface 142 corresponding to each battery. The second discharging interfaces 142 are in parallel relationship, and the second discharging interface 142 of each battery is connected to the first discharging interface 13, which can be indirect connection, that is, the second discharging interface 142 and the first discharging interface 13 can also be connected to some other devices such as control switches and / or voltage boosting modules, etc., which are not limited in particular. The second charging interfaces 141 are in parallel relationship, and the second charging interface 141 of each battery is connected to the first charging interface 12, which can be indirect connection, that is, the second charging interface 141 and the first charging interface 12 can also be connected to some other devices such as switches, etc.

[0061] The vehicle-end load 16 comprises a vehicle-end control module. The energy management system 11 can be connected with the vehicle-end control module to communicate with the vehicle-end control module in real time, and obtain basic information of the vehicle end, such as gear position and accelerator pedal state, through the vehicle-end control module. The energy management system 11 is also connected with the battery management modules in each battery to obtain basic information of each battery, such as health state and remaining capacity, in real time. Then, the energy management system 11 determines whether the new and old battery mixed electric vehicle charging and discharging system is in a charging mode or a discharging mode according to the basic information of the vehicle end and the basic information of the battery. The charging mode is a mode in which the charging pile 15 needs to charge the hybrid battery pack 10, and the discharging mode is a mode in which the hybrid battery pack 10 needs to discharge to the vehicle-end load 16. In an optional embodiment, the energy management system 11 controls the new and old battery mixed electric vehicle charging and discharging system to enter the charging mode when the accelerator pedal is not stepped on, the gear is in the P position, and the remaining capacity of each battery is less than a set value. The energy management system 11 is also used to control the new and old battery mixed electric vehicle charging and discharging system to enter the discharging mode when the accelerator pedal is stepped on and the gear is in the D position.

[0062] In the charging mode, the energy management system 11 can control any battery, such as the first battery, to communicate between the second charging interface 141 corresponding to the first battery and the first charging interface 12, so that the charging pile 15 charges the first battery through the first charging interface 12 and the second charging interface 141 corresponding to the first battery.

[0063] The battery includes a battery cell and a battery management module. The new battery 101 and the old battery 102 in the embodiment are not changed in any way, and everything is based on the original battery cell arrangement and the configuration of the battery management module inside the battery. Each battery includes a charging circuit and a discharging circuit. In the discharging mode, the energy management system 11 controls the discharging circuit in the battery that needs to be discharged, i.e., the second battery, to be turned on, so that the second battery outputs voltage to the second discharging interface 142, and then transmits the voltage output by the second battery to the vehicle end load 16 through the first discharging interface 13, thereby realizing discharging to the vehicle end load 16. In the discharging process, the remaining capacity of the battery is related to the voltage output by the battery. The smaller the remaining capacity, the smaller the output voltage. When the remaining capacity of the second battery decreases to the first preset remaining capacity corresponding to the second battery, such as 5% of the maximum remaining capacity of the second battery, the second battery is in an emergency and needs to be connected to other batteries for discharging. At this time, the energy management system 11 controls the discharging circuit in the third battery to be turned on, so that the third battery outputs voltage to the second discharging interface 142 connected to the third battery, and controls the voltage output from the second discharging interface 142 connected to the third battery to the first discharging interface 13 to be equal to the voltage output from the second battery to the first discharging interface 13 at this time, so that the second battery and the third battery are connected in parallel and carry the load together, ensuring the smoothness of the third battery connection and the stability of the discharging. The energy management system 11 is also used to control the voltage output by the third battery to the first discharging interface 13 to rise to a second preset voltage after the third battery discharges for a first preset time, such as 10S, which is greater than the voltage of the second battery at the end of discharging. Due to the influence of the characteristics of the battery, at the end of discharging, the voltage of the battery will suddenly rise, so the voltage output by the third battery to the first discharging interface 13 needs to be raised to make the voltage output by the third battery to the first discharging interface 13 always greater than the voltage output by the second battery to the first discharging interface 13, avoiding the alternation of the third battery and the second battery in carrying the load during discharging, and ensuring the stability of the discharging switching during discharging.

[0064] Optionally, when controlling the discharging of each battery, the new battery 101 is preferentially used to supply power to the vehicle end load 16. The new battery with more stable performance can be controlled to be discharged in sequence, and then each old battery 102 can be controlled to be discharged in sequence after the discharging of each new battery 101 is completed.

[0065] The technical scheme of the embodiment of the application sets the old battery on the electric vehicle, and configures the corresponding second charging interface and second discharging interface for the old battery, so that the old battery is controlled by the energy management system to charge in the charging mode and discharge in the discharging mode, and then provides electric energy together with the new battery for the electric vehicle, realizes the secondary utilization of the retired battery, and saves the cost. Meanwhile, in the discharging mode, the voltage output by the third battery to the first discharging interface is first equal to the voltage output by the second battery to the first discharging interface and then is raised to be greater than the voltage output by the second battery to the first discharging interface, so that the third battery smoothly enters the discharging mode, and the third battery is always loaded after being connected, the voltage fluctuation caused by the alternate loading of the third battery and the second battery is avoided, and the stability of the battery discharge in the discharging mode is ensured.

[0066] Optionally, the battery energy management system 11 is further configured to control the second battery to stop discharging after a second preset time length, for example, 30 seconds, after the voltage output by the third battery to the first charging interface 12 is raised, and the control of the second battery to stop discharging can be that the discharging circuit in the second battery is turned off. When the voltage output by the third battery to the first discharging interface 13 is raised, for example, to the second preset voltage, the second battery is no longer loaded, the third battery is loaded, and the discharging current in the second battery gradually approaches 0, so that when the discharging current in the second battery is 0, the switch in the discharging circuit is turned off, the sparking problem caused by the operation of the device in the second battery is avoided, and the operation of the second battery is more safe and reliable.

[0067] Figure 2 Another structure schematic diagram of the new and old battery mixed electric vehicle charging and discharging system provided by the embodiment of the application is provided, as shown in Figure 2 The new and old battery mixed electric vehicle charging and discharging system further includes a plurality of charging control switches K1, the charging control switches K1 are arranged corresponding to the batteries, and further, the charging and discharging system further includes the charging control switches K1 corresponding to the batteries one by one.

[0068] For any charging control switch K1, the first end of the charging control switch K1 is connected with the second charging interface 141 corresponding to the battery corresponding to the charging control switch K1, and the second end of the charging control switch K1 is connected with the first charging interface 12.

[0069] The energy management system 11 is connected with the control end of each charging control switch K1. The energy management system 11 is configured to control the first battery corresponding charging control switch K1 to be closed in the charging mode, so as to charge the first battery. The energy management system 11 is also configured to communicate with the charging control module of the charging pile 15 during the charging process of the first battery, and output a synchronization signal in real time. The energy management system 11 is also configured to stop outputting the synchronization signal when the remaining capacity of the first battery reaches a second preset remaining capacity, and control the first battery corresponding charging control switch K1 to be opened and the fourth battery corresponding charging control switch K1 to be closed, so as to make the charging control module re-initiate a handshake request to the hybrid battery pack 10, and make the charging control module perform a handshake operation with the fourth battery to charge the fourth battery. The fourth battery is any battery in the hybrid battery pack 10 except the first battery in the charging mode.

[0070] In the embodiment and the following embodiments, the hybrid battery pack 10 includes one new battery 101 and one old battery 102. The battery charging end of the new battery 101 or the old battery 102 includes a first charging end A1 and a second charging end A2, and the battery discharging end includes a first discharging end B1 and a second discharging end B2. In the charging mode, the energy management system 11 controls the batteries in the hybrid battery pack 10 to be charged in turn in any order. In an optional embodiment, the energy management system 11 controls the second charging interface 141 of each battery to be connected with the first charging interface 12 in the order of the remaining capacity of each battery from large to small, so that the charging pile 15 charges each battery in the order of the remaining capacity of each battery from large to small. Specifically, each battery includes a battery management module and a plurality of series and / or parallel connected battery cells. The battery management module is configured to obtain basic information of the battery, such as the state of health, the remaining capacity, and the internal resistance in real time. The energy management system 11 can be connected with the battery management module of each battery to obtain the basic information of the battery, and then determine the order of the batteries arranged in the order of the remaining capacity from large to small in the hybrid battery pack 10. In the embodiment, the battery with a larger remaining capacity is charged first, and when the battery is charged to a preset capacity, the charging is switched to another battery. In this way, the battery can be charged to a state with sufficient power in a short time, so that the user can start the electric vehicle at any time when the user has a sudden discharging demand, and the electric vehicle can be switched to the discharging mode. In the discharging mode, the battery with sufficient power is stably discharged, and the frequent switching of the battery in the discharging mode due to the insufficient power of the battery can be avoided to ensure stable power supply.

[0071] In this embodiment, the remaining capacity of the new battery 101 is greater than that of the old battery 102. In the charging mode, after the charging pile is connected with the first charging interface 12, the energy management system 11 is activated. The energy management system 11 controls the new battery 101 (the first battery) to turn on the corresponding charging control switch K1 according to the obtained basic information of each battery, and controls the battery management module of the new battery 101 to be in an activated state to interact with other devices, and controls the old battery 102 (the fourth battery) to be in a silent state and not to interact with the outside. The charging control module of the charging pile 15 initiates a handshake request to the hybrid battery pack 10. The new battery 101 in the activated state responds to the handshake request and performs a handshake operation with the charging control module. The new battery 101 transmits its charging parameters to the charging control module, so that the charging control module charges the new battery 101 according to the charging parameters of the new battery 101. When the energy management system 11 determines that the new battery 101 is charged to the second preset remaining capacity corresponding to the new battery 101, such as 95% of the maximum remaining capacity of the new battery 101, the energy management system 11 stops sending a synchronization signal to the charging control module, and controls the charging control switch K1 of the new battery 101 to be disconnected and the charging control switch of the old battery 102 to be closed, and controls the battery management module of the old battery 102 to be in an activated state and the battery management module of the new battery 101 to be in a silent state. That is, the battery management module corresponding to the charging control switch K1 in the closed state is in an activated state, and the battery management modules of other batteries are in a silent state. When the charging control module does not receive the synchronization signal, it will initiate a handshake operation to the hybrid battery pack 10 again. At this time, the old battery 102 performs a handshake operation with the charging control module and transmits its charging parameters to the charging control module, so that the charging control module charges the old battery 102 according to the charging parameters of the old battery 102.

[0072] In this embodiment, the energy management system is used to cause some communication failures, such as stopping outputting a synchronization signal, when the battery charged in the last charging is charged to the second preset remaining capacity. In this way, the charging pile 15 can initiate a handshake request to the hybrid battery pack 10 again, and then perform a handshake operation with the battery charged next time, and then switch the charged battery to the next battery, without the need to plug in and plug out the charging gun of the charging pile to realize communication switching, thereby improving the charging efficiency and saving manpower.

[0073] With reference to the foregoing description Figure 2Optionally, the electric vehicle charging and discharging system with new and old batteries mixed together further comprises at least two voltage conversion modules 17, and the voltage conversion modules 17 are arranged in correspondence with the batteries. Specifically, the electric vehicle charging and discharging system with new and old batteries mixed together further comprises a voltage conversion module 17 corresponding to each battery. For any voltage conversion module 17, the first end of the voltage conversion module 17 is connected to the second discharging interface 142 corresponding to the battery corresponding to the voltage conversion module 17, the second end of the voltage conversion module 17 is connected to the first discharging interface 13, and the energy management system 11 is connected to the control end of each voltage conversion module 17. The energy management system 11 is configured to, in the discharging mode, control the voltage conversion module 17 corresponding to the third battery to output the same voltage as the second battery when the remaining capacity of the second battery reaches the first preset remaining capacity, and is further configured to raise the voltage output by the voltage conversion module 17 corresponding to the third battery after the third battery discharges to the vehicle end load 16 for the first preset time length.

[0074] Optionally, one battery can correspond to one voltage conversion module 17. In the embodiment, only one new battery 101 and one old battery 102 are included, and the new battery 101 is controlled to discharge first and then the old battery 102 is controlled to discharge. Therefore, only one voltage conversion module 17 can be arranged for the old battery 102. The new battery 101 can also be provided with one voltage conversion module 17, and the voltage output by the voltage conversion module 17 is equal to the voltage output by the new battery 101 to the voltage conversion module 17.

[0075] The voltage conversion module 17 can include a direct current-direct current converter to convert a direct current voltage into another direct current voltage. In the embodiment, in the discharging mode, taking the second battery as the new battery 101 and the third battery as the old battery 102 as an example, the energy management system 11 controls the discharging circuit in the old battery 102 to be conductive through the battery management module in the old battery 102 in the embodiment, so that the old battery 102 outputs a voltage to the second discharging interface 142 connected to the old battery 102. The voltage conversion module 17 corresponding to the old battery 102 converts the voltage of the old battery 102 into a first preset voltage. At this time, the old battery 102 discharges together with the new battery 101. After the old battery 102 discharges for a first preset time length, such as 10 seconds, the energy management system 11 controls the voltage output by the voltage conversion module 17 to be boosted to a second preset voltage, so that the voltage output by the voltage conversion module 17 is greater than the voltage output by the new battery 101. The discharging battery is switched to the old battery 102, and the current in the new battery 101 gradually approaches 0. Then, the energy management system controls the discharging circuit in the new battery 101 to be disconnected, so as to avoid the problem of sparking caused by controlling the discharging circuit in the new battery 101 to be disconnected when the new battery 101 is live.

[0076] Continuing to refer to Figure 2Optionally, the electric vehicle charging and discharging system with new and old batteries mixed together further comprises an anti-backflow module 18 corresponding to each battery. For any anti-backflow module 18, the first end of the anti-backflow module 18 is connected to the second discharging interface 142 corresponding to the battery corresponding to the anti-backflow module 18, and the second end of the anti-backflow module 18 is connected to the first discharging interface 13.

[0077] In the embodiment, one new battery 101 and one old battery 102 are exemplarily shown, and the new battery 101 is controlled to discharge first and then the old battery 102 is controlled to discharge. Therefore, the new battery 101 can not be provided with the anti-backflow module 18. When the hybrid battery pack 10 comprises at least two new batteries 101 and / or two old batteries 102, an anti-backflow module 18 can be provided for each battery. The anti-backflow module 18 is used to control the electric energy output by the battery to flow unidirectionally from the second discharging interface 142 corresponding to the battery to the first discharging interface 13, so as to avoid the voltage output by the voltage conversion module 17 corresponding to other batteries from flowing to the second discharging interface 142 corresponding to the battery to charge the battery, thereby avoiding the occurrence of unintended circulating current caused by any battery charging another battery through the voltage conversion module. Optionally, the anti-backflow module 18 comprises a diode, the anode of the diode is connected to the second discharging interface 142, and the cathode of the diode is connected to the first discharging interface 13.

[0078] Figure 3 A flowchart of a control method of an electric vehicle charging and discharging system with new and old batteries mixed together provided by the embodiment of the present application, Figure 3 The control flow is applicable to control the electric vehicle charging and discharging system with new and old batteries mixed together in any of the above embodiments, and the control flow is described with reference to Figure 1 and Figure 3 The control method comprises the following steps.

[0079] S110: In the charging mode, the energy management system 11 controls the second charging interface 141 corresponding to the first battery to be in communication with the first charging interface 12, so that the charging pile 15 charges the first battery; wherein the first battery is any battery in the hybrid battery pack 10.

[0080] The charging gun of the charging pile 15 is connected with the first charging interface 12, and the energy management system 11 is activated. The energy management system 11 activates the battery management modules of each battery in the hybrid battery pack 10. After the energy management system 11 is activated, it communicates with the vehicle-end control module included in the vehicle-end load 16 and communicates with each battery management module to obtain basic information of the vehicle end. According to the basic information of the vehicle end and the basic information of the battery, it is determined that the new and old battery mixed electric vehicle charging and discharging system is in the charging mode. In the charging mode, the energy management system 11 controls each battery to be charged in turn. For any charged battery, the energy management system 11 controls the second charging interface 141 corresponding to the battery to be in communication with the first charging interface 12, so that the electric energy output by the charging pile 15 is transmitted to the battery through the first charging interface 12 and the second charging interface 141, and the charging of the battery is realized.

[0081] S120: In the discharging mode, when the remaining capacity of the second battery reaches the first preset remaining capacity, the energy management system 11 controls the third battery to output the same voltage as the second battery to the first discharging interface 13.

[0082] Specifically, in the discharging mode, when the remaining capacity of the second battery reaches the first preset remaining capacity, the energy management system 11 controls the voltage output by the third battery to the first discharging interface 13 to be equal to the first preset voltage. The first preset voltage is equal to the size of the voltage output by the second battery to the first discharging interface when the remaining capacity of the second battery reaches the first preset remaining capacity. The energy management system 11 communicates with the vehicle-end control module of the vehicle-end load 16 in real time to obtain basic information of the vehicle end, and determines when the new and old battery mixed electric vehicle charging and discharging system is in the discharging mode according to the basic information of the vehicle end. For example, if the gear of the electric vehicle is D gear and the accelerator pedal is pressed, it is determined that the new and old battery mixed electric vehicle charging and discharging system is in the discharging mode, and the hybrid battery pack 10 needs to provide electric energy to the vehicle-end load 16. In the discharging mode, the energy management system 11 controls each new battery 101 to discharge in turn, and when the last new battery 101 finishes discharging, it switches to any old battery 102 to discharge.

[0083] When the remaining capacity of the second battery reaches the first preset remaining capacity corresponding to the second battery, for example, 5% of the maximum remaining capacity of the second battery, the energy management system 11 controls the voltage output by the third battery to the first discharging interface 13 to be equal to the first preset voltage, that is, controls the voltage output by the third battery to the first discharging interface 13 to be equal to the voltage output by the second battery to the first discharging interface 13 at this time. The voltages output to the first discharging interface 13 are the same, and they are connected in parallel together to carry load together, ensuring that the third battery smoothly enters the discharging mode.

[0084] S130: The energy management system 11 raises the voltage output by the third battery to the first discharging interface 13 after the third battery discharges for a first preset time.

[0085] Further, the raised voltage is a second preset voltage, that is, the energy management system 11 controls the voltage output by the third battery to the first discharge interface 13 to be equal to the second preset voltage after the third battery is discharged for a first preset time length. The second battery and the third battery are different batteries, the second battery is the battery currently being discharged, the third battery is another battery, and the second preset voltage is greater than the first preset voltage.

[0086] The energy management system 11 controls the voltage output by the third battery to the first discharge interface 13 to be raised to the second preset voltage after the third battery is discharged for a first preset time length, such as 10 seconds, to be greater than the voltage of the second battery at the end of the discharge. Due to the influence of the characteristics of the battery, at the end of the discharge, the voltage of the battery will suddenly rise, so the voltage output by the third battery to the first discharge interface 13 needs to be raised to ensure that the voltage output by the third battery to the first discharge interface 13 is always greater than the voltage output by the second battery to the first discharge interface 13, avoiding the third battery and the second battery alternatingly carrying the load during the discharge process, and ensuring the stability of the discharge switching during the discharge process.

[0087] The technical scheme of the embodiment of the application controls the old battery to charge in the charging mode and discharge in the discharging mode, and then provides power for the electric vehicle together with the new battery, realizes the secondary use of the retired battery, and saves costs. At the same time, in the discharging mode, the voltage output by the third battery to the first discharge interface is first equal to the voltage output by the second battery to the first discharge interface and then raised to be greater than the voltage output by the second battery to the first discharge interface, so that the third battery smoothly enters the discharging mode, and after the third battery is connected, the third battery is always carrying the load, avoiding the voltage fluctuation caused by the third battery and the second battery alternatingly carrying the load, and ensuring the stability of the battery discharge in the discharging mode.

[0088] The charging pile includes a charging control module, each battery includes a battery management module, and the new and old battery mixed electric vehicle charging and discharging system further includes a charging control switch K1 corresponding to each battery; for any charging control switch K1, the first end of the charging control switch K1 is connected with the second charging interface 141 corresponding to the charging control switch K1, and the second end of the charging control switch K1 is connected with the first charging interface 12. Figure 4 Another flowchart of a control method of a new and old battery mixed electric vehicle charging and discharging system provided by the embodiment of the application is shown in the figure, Figure 4 The flowchart shown is a flowchart in the charging mode, and reference is made to Figure 2 and Figure 4 The control method includes:

[0089] S111: In the charging mode, the energy management system 11 controls the first battery corresponding charging control switch K1 to close, so that the second charging interface 141 corresponding to the first battery is in communication with the first charging interface 12.

[0090] In this embodiment, the hybrid battery pack 10 only includes one new battery 101 and one old battery 102. In the charging mode, the charging pile 15 activates the energy management system 11, and the energy management system 11 communicates with each battery management module to determine the currently required priority charging battery according to the charging needs, and the determination conditions include at least one of the remaining power, the fault state, and the last charging flag. In this embodiment, the energy management system 11 controls each second charging interface 141 to be in communication with the first charging interface 12 in the order of the remaining capacity of each battery in the hybrid battery pack 10 from large to small, so that the charging pile 15 charges each battery in the order of the remaining capacity of each battery from large to small. In this embodiment, the remaining power of the new battery 101 is greater than that of the old battery 102, and the new battery 101 is charged first and then the old battery 102 is charged. In this embodiment, the first battery is the new battery 101. After the energy management system 11 controls the new battery 101 corresponding charging control switch K1 to be conductive, the second charging interface 141 corresponding to the new battery 101 and the first charging interface 12 are in communication, and the subsequent charging process is performed.

[0091] S121: The charging control module initiates a handshake request to the hybrid battery pack 10 to perform a handshake operation with the first battery.

[0092] After the energy management system 11 controls the first battery corresponding charging control switch K1 to close, the battery management module of the first battery is in an activated state, and the other batteries are in a silent state. Therefore, after the charging control module initiates a handshake request to the hybrid battery pack 10, the first battery can respond and perform a handshake operation with the charging control module to establish a communication connection.

[0093] S131: The battery management module of the first battery transmits the charging parameters of the first battery to the charging control module.

[0094] After the first battery performs a handshake operation with the charging control module, real-time information interaction can be realized, and the first battery transmits the charging parameters corresponding to the first battery, such as the required charging current, to the charging control module.

[0095] S141: The charging control module outputs an electric signal to the first battery according to the charging parameters corresponding to the first battery to charge the first battery; wherein the charging parameters at least include the size of the charging current. The electric signal includes a current signal.

[0096] The charging control module receives the charging parameters corresponding to the first battery, and outputs corresponding electrical signals according to the charging parameters required by the first battery, so that the charging control module charges the first battery according to the charging parameters of the first battery. If the charging current required by the first battery is 10A, the charging control module outputs a current of 10A after receiving the charging parameters of the first battery, thereby realizing charging of the first battery with a current of 10A.

[0097] S151: The energy management system 11 outputs a synchronization signal to the charging control module in real time.

[0098] The energy management system 11 interacts with the charging control module in real time through the output synchronization signal. After receiving the synchronization signal, the charging control module normally outputs electrical signals to realize uninterrupted charging of the first battery.

[0099] S161: When the remaining capacity of the first battery reaches the second preset remaining capacity, the energy management system 11 stops outputting the synchronization signal, and controls the charging control switch K1 corresponding to the first battery to be open and the charging control switch K1 corresponding to the fourth battery to be closed. The fourth battery is any battery in the hybrid battery pack in the charging mode except the first battery.

[0100] When the remaining capacity of the first battery reaches the second preset remaining capacity corresponding to the first battery, the energy management system 11 stops outputting the synchronization signal, and the second preset remaining capacity corresponding to the first battery is 95% of the maximum remaining capacity of the first battery. When the first battery is about to be fully charged, the energy management system 11 itself causes a synchronization signal output failure, no longer outputs the synchronization signal, controls the charging control switch K1 corresponding to the first battery to be open, so that the connection between the first battery and the charging pile 15 is disconnected, and the charging pile 15 stops charging the first battery. The charging control switch K1 corresponding to the fourth battery is closed to communicate between the fourth battery and the charging pile 15. In this embodiment, the charging control switch corresponding to the new battery 101 is controlled to be open, and the charging control switch K1 corresponding to the old battery 102 is controlled to be closed.

[0101] S171: When the charging control module does not receive the synchronization signal, it reinitiates a handshake request to the hybrid battery pack 10 to perform a handshake operation with the fourth battery.

[0102] After the charging control module does not receive the synchronization signal, it reinitiates a handshake request to attempt to reestablish a connection with the hybrid battery pack 10. In this embodiment, after the energy management system 11 controls the charging control switch K1 of the fourth battery to be closed, it simultaneously controls the fourth battery to be in an activated state and the other batteries to be in a silent state. The battery management modules of the other batteries do not communicate with the charging control module, so after the charging control module initiates a handshake request, only the battery management module of the fourth battery is in an activated state and performs a handshake operation with the charging control module.

[0103] S181: The battery management module of the fourth battery transmits the charging parameter corresponding to the fourth battery to the charging control module.

[0104] After the fourth battery performs the handshake operation with the charging control module of the charging pile 15, information interaction can be performed, and the fourth battery transmits the charging parameter of the fourth battery, such as the size of the required charging current of the fourth battery, to the charging control module.

[0105] S191: The charging control module outputs an electric signal to the fourth battery according to the charging parameter corresponding to the fourth battery, so as to charge the fourth battery.

[0106] If the current required by the fourth battery is 15A, the charging control module outputs a current of 15A to charge the fourth battery.

[0107] In the embodiment, when the charging of the first battery is about to end, the energy management system itself generates a synchronization signal output fault, so that the charging pile again performs a handshake request with the hybrid battery pack, and then switches the communication connection between the first battery and the charging control module to the communication connection between the fourth battery and the charging control module, and further causes the charging control module to charge the fourth battery according to the charging parameter of the fourth battery, thereby avoiding the need to plug in and plug out the charging gun of the charging pile when switching from charging the first battery to charging the fourth battery, improving the charging efficiency and reducing the labor cost.

[0108] Reference Figure 2 The new and old battery mixed electric vehicle charging and discharging system further includes a voltage conversion module 17 corresponding to each battery, and the connection relationship of the voltage conversion module is the same as described above, which will not be described again. Figure 5 Another flowchart of a control method of a new and old battery mixed electric vehicle charging and discharging system provided by the embodiment of the application is shown in reference Figure 2 and Figure 5 The control method includes the following steps.

[0109] S112: In the charging mode, the energy management system 11 controls the second charging interface 141 corresponding to the first battery to be in communication with the first charging interface 12, so that the charging pile 15 charges the first battery.

[0110] S122: In the discharging mode, when the remaining capacity of the second battery reaches the first preset remaining capacity, the energy management system 11 controls the discharging circuit in the third battery to be closed to make the third battery output a voltage to the second discharging interface 142 connected to the third battery.

[0111] S132: The energy management system controls the voltage conversion module corresponding to the third battery to output the same voltage as the second battery.

[0112] S142: The energy management system 11 lifts the voltage output by the voltage conversion module corresponding to the third battery after the third battery discharges for the first preset time length.

[0113] S152: The energy management system 11 controls the second battery to stop discharging after the second preset time length after the voltage output by the third battery to the first discharging interface 13 is lifted.

[0114] In this embodiment, when the voltage output by the third battery to the first discharging interface 13 is equal to the second preset voltage, the second battery is no longer loaded, the third battery is loaded, and the discharging current in the second battery gradually approaches 0, so that when the discharging current in the second battery is 0, the switch in the discharging circuit is controlled to be turned off, thereby avoiding the problem of sparking caused by operating the devices in the second battery while being electrified, and making the operation of the second battery more safe and reliable.

[0115] It should be understood that the various forms of flow shown above can be used to reorder, add or delete steps. For example, each step described in the present application can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, which is not limited herein.

[0116] The above specific embodiments do not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent replacement and improvement within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A new and old battery mixed electric vehicle charging and discharging system, characterized in that, The application relates to a hybrid battery pack and an energy management system thereof. The hybrid battery pack comprises at least two batteries, at least one of which is a new battery and at least one of which is an old battery. The hybrid battery pack comprises a first charging interface for connecting to a charging pile and a first discharging interface for connecting to a vehicle load. The hybrid battery pack comprises a charging and discharging interface group corresponding to each battery, wherein each charging and discharging interface group comprises a second charging interface and a second discharging interface, and each second discharging interface is connected to the first discharging interface. The energy management system is configured to control the second charging interface corresponding to a first battery to be in communication with the first charging interface in a charging mode, and the energy management system is further configured to control a third battery to output the same voltage as a second battery to the first discharging interface when the remaining capacity of the second battery reaches a first preset remaining capacity in a discharging mode, and to raise the voltage output by the third battery to the first discharging interface after the third battery discharges for a first preset time length. The hybrid battery pack further comprises a charging control switch corresponding to each battery. The first end of each charging control switch is connected to the second charging interface corresponding to the battery corresponding to the charging control switch, and the second end of the charging control switch is connected to the first charging interface.

2. The new and old battery hybrid electric vehicle charge and discharge system according to claim 1, characterized by, The energy management system is connected to the control end of each charging control switch, and the energy management system is configured to control the charging control switch corresponding to the first battery to be closed in the charging mode to charge the first battery. The energy management system is further configured to communicate with a charging control module of the charging pile during the charging of the first battery, output a synchronization signal in real time, and stop outputting the synchronization signal when the remaining capacity of the first battery reaches a second preset remaining capacity, and control the charging control switch corresponding to the first battery to be opened and the charging control switch corresponding to a fourth battery to be closed to enable the charging control module to initiate a handshake request to the hybrid battery pack again, so that the charging control module performs a handshake operation with the fourth battery and charges the fourth battery. The fourth battery is any battery in the hybrid battery pack except the first battery in the charging mode.

3. The new and old battery hybrid electric vehicle charge-discharge system according to claim 1, characterized by, Further comprising a voltage conversion module corresponding to each of the batteries, for any of the voltage conversion modules, a first end of the voltage conversion module is connected with a second discharge interface corresponding to the battery corresponding to the voltage conversion module, a second end of the voltage conversion module is connected with the first discharge interface, the energy management system is connected with a control end of each of the voltage conversion modules, the energy management system is used to control the voltage conversion module corresponding to the third battery to output the same voltage as the second battery when the remaining capacity of the second battery reaches the first preset remaining capacity in the discharge mode, and is further used to lift the voltage output by the voltage conversion module corresponding to the third battery after the third battery is discharged for the first preset time length.

4. The new and old battery hybrid electric vehicle charge-discharge system according to claim 3, characterized by, Further comprising an anti-backflow module corresponding to each of the batteries, for any of the anti-backflow modules, a first end of the anti-backflow module is connected with a second discharge interface corresponding to the battery corresponding to the anti-backflow module, and a second end of the anti-backflow module is connected with the first discharge interface.

5. A control method of a charge-discharge system of a hybrid electric vehicle of new and old batteries, characterized by, The new and old battery mixed electric vehicle charging and discharging system of any one of claims 1-4; The control method of the new and old battery mixed electric vehicle charging and discharging system comprises: In the charging mode, the energy management system controls the second charging interface corresponding to the first battery to be in communication with the first charging interface, so that the charging pile charges the first battery; the first battery is any battery in the mixed battery pack; In the discharge mode, the energy management system controls the third battery to output the same voltage as the second battery to the first discharge interface when the remaining capacity of the second battery reaches the first preset remaining capacity; The energy management system lifts the voltage output by the third battery to the first discharge interface after the third battery is discharged for the first preset time length; wherein the second battery and the third battery are different batteries.

6. The control method of the new-old battery hybrid electric vehicle charge-discharge system according to claim 5, characterized by, The charging pile comprises a charging control module, each of the batteries comprises a battery management module; the new and old battery mixed electric vehicle charging and discharging system further comprises a charging control switch corresponding to each of the batteries; for any of the charging control switches, a first end of the charging control switch is connected with the second charging interface corresponding to the charging control switch, and a second end of the charging control switch is connected with the first charging interface; The energy management system controls the second charging interface corresponding to the first battery to be in communication with the first charging interface, so that the charging pile charges the first battery, which comprises: The energy management system controls the charging control switch corresponding to the first battery to be closed, so that the second charging interface corresponding to the first battery is in communication with the first charging interface; The charging control module initiates a handshake request to the mixed battery pack to perform a handshake operation with the first battery; The battery management module of the first battery transmits the charging parameters of the first battery to the charging control module; The charging control module outputs an electric signal to the first battery according to the charging parameter corresponding to the first battery, so as to charge the first battery; wherein the charging parameter at least includes the size of the charging current.

7. The control method of the new-old battery hybrid electric vehicle charge-discharge system according to claim 6, characterized by, After the charging control module outputs the electric signal to the first battery according to the charging parameter corresponding to the first battery, the method further comprises: The energy management system outputs a synchronization signal to the charging control module in real time; When the remaining capacity of the first battery reaches a second preset remaining capacity, the energy management system stops outputting the synchronization signal, controls the charging control switch corresponding to the first battery to be turned off, and controls the charging control switch corresponding to the fourth battery to be turned on; the fourth battery is any battery in the hybrid battery pack except the first battery in the charging mode; When the charging control module does not receive the synchronization signal, the charging control module reinitiates a handshake request to the hybrid battery pack, so as to perform a handshake operation with the fourth battery; The battery management module of the fourth battery transmits the charging parameter corresponding to the fourth battery to the charging control module; The charging control module outputs an electric signal to the fourth battery according to the charging parameter corresponding to the fourth battery, so as to charge the fourth battery.

8. The control method of the new-old battery hybrid electric vehicle charge-discharge system according to claim 5, characterized by, The energy management system controls each second charging interface to be sequentially communicated with the first charging interface in the order of the remaining capacity of each battery in the hybrid battery pack from large to small, so that the charging pile sequentially charges each battery in the order of the remaining capacity of each battery from large to small.

9. The control method of the new-old battery hybrid electric vehicle charge-discharge system according to claim 5, characterized by, The electric vehicle charging and discharging system with mixed new and old batteries further comprises a voltage conversion module corresponding to each battery, for any voltage conversion module, a first end of the voltage conversion module is connected with a second discharging interface corresponding to the battery corresponding to the voltage conversion module, a second end of the voltage conversion module is connected with the first discharging interface, and a control end of each voltage conversion module is connected with the energy management system; When the remaining capacity of the second battery reaches a first preset remaining capacity, the energy management system controls the third battery to output the same voltage as the second battery to the first discharging interface, comprising: When the remaining capacity of the second battery reaches a first preset remaining capacity, the energy management system controls a discharging circuit in the third battery to be closed, so that the third battery outputs a voltage to the second discharging interface connected with the third battery; The energy management system controls the voltage conversion module corresponding to the third battery to output the same voltage as the second battery; After the third battery discharges for a first preset time, the energy management system raises the voltage output by the third battery to the first discharging interface, comprising: After the third battery discharges for a first preset time, the energy management system raises the voltage output by the voltage conversion module corresponding to the third battery.

10. The control method of the new-old battery hybrid electric vehicle charge-discharge system according to claim 5, characterized by, After the energy management system raises the voltage output by the third battery to the first discharging interface after the third battery discharges for a first preset time, the method further comprises: The energy management system controls the second battery to stop discharging after a second preset time length of lifting the voltage output by the third battery to the first discharging interface.

Images