Battery system, control method thereof and battery pack

Abstract

The invention relates to a battery system, a control method thereof and a battery pack. The battery system comprises a first power supply end, a second power supply end, a first battery pack, a second battery pack, a first switch unit, a second switch unit, a power conversion unit and a control unit, the first end of the first battery pack is connected with a first power supply end through the first switch unit, the second end of the first battery pack is connected with the first power supply end through the second switch unit after being connected with the first end of the second battery pack, and the second end of the second battery pack is connected with a second power supply end; the first switch unit and the second switch unit are respectively connected with the control unit and are used for receiving the control level output by the control unit so as to switch on one of the first switch unit and the second switch unit; the power conversion unit is connected with the first battery pack, the second battery pack and the control unit and used for receiving the control level output by the control unit to achieve energy transfer between the second battery pack and the first battery pack. The system can be compatible with a plurality of different voltage platforms, so that the whole system can meet more working scenes.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and more specifically, to a battery system and a control method thereof, and a battery pack. Background Art

[0002] With the vigorous development of the new energy industry, lithium-ion batteries are being used in more and more scenarios, and the battery market for electric bicycles and tricycles has seen the emergence of scenarios where users can replace or rent batteries. Since electric vehicles have several lithium battery voltage platforms such as 48V, 60V, and 72V, the corresponding batteries include 16-series, 20-series, and 24-series lithium iron phosphate or 13-series, 17-series, and 20-series lithium manganese oxide battery packs. In order to reduce the number of battery models put on the market, the battery pack needs to be designed to be compatible with multiple different voltage platforms. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a battery system and a control method thereof, and a battery pack, in view of the defect that the above-mentioned battery system in the prior art is difficult to be compatible with multiple different voltage platforms.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing a battery system, including: a first power supply end, a second power supply end, a first battery pack, a second battery pack, a first switch unit, a second switch unit, a power conversion unit and a control unit;

[0005] The first end of the first battery pack is connected to the first power supply end via the first switch unit, the second end of the first battery pack is connected to the first end of the second battery pack and then connected to the first power supply end via the second switch unit, and the second end of the second battery pack is connected to the second power supply end;

[0006] The first switch unit and the second switch unit are respectively connected to the control unit, and are used to receive a control level output by the control unit to switch one of the first switch unit and the second switch unit on;

[0007] The power conversion unit is connected to the first battery pack, the second battery pack and the control unit, and is used to receive a control level output by the control unit to achieve energy transfer between the second battery pack and the first battery pack.

[0008] Preferably, in the battery system of the present invention, the control unit is used to switch the first switch unit on and turn off the power conversion unit;

[0009] So that the first battery pack and the second battery pack provide power output through the first power supply end; or external power input charges the first battery pack and the second battery pack through the first power supply end.

[0010] Preferably, in the battery system of the present invention, the first switch unit includes a first discharging switch and a first charging switch;

[0011] The control unit is used to switch on the first discharge switch so that the first battery pack and the second battery pack provide power output through the first power supply terminal; or

[0012] The control unit is used to switch on the first charging switch so that an external power input charges the first battery pack and the second battery pack through the first power supply terminal.

[0013] Preferably, in the battery system of the present invention, the control unit is further used to switch the second switch unit on and turn on the power conversion unit;

[0014] So that the first battery group supplies power to the second battery group through the power conversion unit, and the second battery group provides power output through the first power supply terminal, or external power input charges the second battery group through the first power supply terminal, and the second battery group charges the first battery group through the power conversion unit.

[0015] Preferably, in the battery system of the present invention, the second switch unit includes a second discharge switch and a second charge switch;

[0016] The control unit is used to switch on the second discharge switch so that the second battery pack provides power output through the first power supply terminal; or

[0017] The control unit is used to switch on the second charging switch so that the external power input charges the second battery pack through the first power terminal.

[0018] Preferably, in the battery system described in the present invention, the first battery pack includes a plurality of battery cells connected in series and a short-circuit protection unit connected in series with the battery cells, and / or the second battery pack includes a plurality of battery cells connected in series.

[0019] The present invention also constructs a battery pack, comprising the battery system as described above.

[0020] The present invention also constructs a battery system control method, the battery system comprising: a first power supply terminal, a second power supply terminal, a first battery pack, a second battery pack, a first switch unit, a second switch unit and a power conversion unit;

[0021] The first end of the first battery pack is connected to the first power supply end via the first switch unit, the second end of the first battery pack is connected to the first end of the second battery pack and then connected to the first power supply end via the second switch unit, and the second end of the second battery pack is connected to the second power supply end; the power conversion unit connects the first battery pack and the second battery pack;

[0022] The control method comprises:

[0023] Switching the first switch unit on and turning off the power conversion unit so that the first battery pack and the second battery pack provide power output through the first power supply terminal, or allowing external power input to charge the first battery pack and the second battery pack through the first power supply terminal; or

[0024] Switch the second switch unit on, and turn on the power conversion unit, so that the first battery group supplies power to the second battery group through the power conversion unit, and the second battery group provides a power output through the first power supply terminal, or allow external power input to charge the second battery group through the first power supply terminal, and the second battery group charges the first battery group through the power conversion unit.

[0025] Preferably, in the battery system control method of the present invention, the first switch unit includes a first discharge switch and a first charge switch; when the first switch unit is switched on, the control method further includes:

[0026] Switching the first discharge switch on so that the first battery pack and the second battery pack provide power output through the first power supply terminal; or

[0027] The first charging switch is switched on so that an external power input charges the first battery pack and the second battery pack through the first power terminal.

[0028] Preferably, in the battery system control method of the present invention, the second switch unit includes a second discharge switch and a second charge switch; when the second switch unit is switched on, the control method further includes:

[0029] Switching the second discharge switch on so that the second battery pack provides power output through the first power supply terminal; or

[0030] The second charging switch is switched on so that the external power input charges the second battery pack through the first power terminal.

[0031] A battery system and a control method thereof, as well as a battery pack implementing the present invention have the following beneficial effects: being compatible with a plurality of different voltage platforms so that the entire system can meet more working scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0033] Figure 1 It is a structural schematic diagram of an embodiment of a battery system of the present invention;

[0034] Figure 2 is a structural schematic diagram of another embodiment of a battery system of the present invention;

[0035] Figure 3 It is a partial circuit schematic diagram of an embodiment of a battery system of the present invention. DETAILED DESCRIPTION

[0036] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0037] like Figure 1 FIG. 1 shows an embodiment of a battery system of the present invention. Figure 1 In one embodiment of a battery system of the present invention shown, the battery system includes a first power supply terminal 111, a second power supply terminal 112, a first battery group 121, a second battery group 122, a first switch unit 131, a second switch unit 132, a power conversion unit 140 and a control unit 150; the first end of the first battery group 121 is connected to the first power supply terminal 111 via the first switch unit 131, the second end of the first battery group 121 is connected to the first end of the second battery group 122 and then connected to the first power supply terminal 111 via the second switch unit 132, and the second end of the second battery group 122 is connected to the second power supply terminal 112; the first switch unit 131 and the second switch unit 132 are respectively connected to the control unit 150, and are used to receive the control level output by the control unit 150 to switch one of the first switch unit 131 and the second switch unit 132 to be turned on; the power conversion unit 140 is connected to the first battery group 121, the second battery group 122 and the control unit 150, and is used to receive the control level output by the control unit 150 to realize energy transfer between the second battery group 122 and the first battery group 121.

[0038] Specifically, the battery system is connected to a load or a power supply device through the first power terminal 111 and the second power terminal 112. The first battery group 121 and the second battery group 122 are connected in series. The control unit 150 controls one of the first switch unit 131 and the second switch unit 132 to be turned on, that is, at the same time point, only one of the first switch unit 131 and the second switch unit 132 is in a conducting state. When the control unit 150 controls the first switch unit 131 to be turned on, the second switch unit 132 is set to be in a turned-off state, and the first power terminal 111 forms a main working circuit with the second power terminal 112 by connecting the first battery group 121 and the second battery group 122 in series. If the first power terminal 111 and the second power terminal 112 are connected to a load at this time, the load can be powered by the first battery group 121 and the second battery group 122. If the first power terminal 111 and the second power supply are connected to a power supply at this time, the first battery group 121 and the second battery group 122 can be charged simultaneously through the external power input provided by the power supply. When the control unit 150 controls the second switch unit 132 to be turned on, the first switch unit 131 is set to the off state. The first power supply terminal 111 forms a main working circuit with the second power supply terminal 112 through the second battery pack 122. If the first power supply terminal 111 and the second power supply terminal 112 are connected to a load at this time, the load can be powered by the second battery pack 122. If the first power supply terminal 111 and the second power supply are connected to a power supply at this time, the second battery pack 122 can be charged by the external power input provided by the power supply. At the same time, the control unit 150 controls the working state of the power conversion unit 140 so that the power conversion unit 140 is in the off state or the working state. When the power conversion unit 140 is in the working state, the control unit 150 can control the power conversion unit 140 to convert the output of the first battery pack 121 into energy and input it to the second battery pack 122 to power the second battery pack 122; or control the power conversion unit 140 to convert the output of the second battery pack 122 into energy and input it to the first battery pack 121 to power the first battery pack 121.

[0039] Through the above process, the control unit 150 can switch the first battery group 121 and the second battery group 122 to supply power as needed, and then adjust the output voltage of the battery system (corresponding to the output voltage of the first power supply end and the second power supply end) so that the battery system can meet different power supply voltage platforms.

[0040] In one embodiment, the control unit 150 is used to switch the first switch unit 131 on and turn off the power conversion unit 140; so that the first battery group 121 and the second battery group 122 provide power output through the first power terminal 111; or the external power input charges the first battery group 121 and the second battery group 122 through the first power terminal 111. Specifically, in the specific operation process of the battery system, the first switch unit 131 can be switched on by the control unit 150, and the power conversion unit 140 can be turned off at the same time. When the battery system needs to be connected to a high power output platform, the first battery group 121 and the second battery group 122 need to provide output at the same time to obtain the required output voltage. Therefore, the control unit 150 needs to control the first switch unit 131 to be turned on according to the corresponding control level, and the first battery group 121 and the second battery group 122 form a series connection relationship, and form a main working circuit with the first power terminal 111 and the second power terminal 112. If the first power terminal 111 and the second power terminal 112 are connected to a load at this time, the load can be powered by the first battery group 121 and the second battery group 122. If the first power supply terminal 111 and the second power supply terminal 112 are connected to a power supply, the first battery pack 121 and the second battery pack 122 can be charged simultaneously by the power supply. At this time, because the first battery pack 121 and the second battery pack 122 are both involved in the main working circuit, there is no need to transfer energy between the first battery pack 121 and the second battery pack 122, and the power conversion unit 140 is set to the off state.

[0041] Further, such as Figure 2 As shown, the first switch unit 131 includes a first discharge switch 1311 and a first charging switch 1312; the control unit 150 is used to switch the first discharge switch 1311 on so that the first battery group 121 and the second battery group 122 provide power output through the first power supply terminal 111; or the control unit 150 is used to switch the first charging switch 1312 on so that the external power input charges the first battery group 121 and the second battery group 122 through the first power supply terminal 111. Specifically, in the first switch unit 131, the first discharge switch 1311 and the first charging switch 1312 are used to control whether the main working circuit is in a discharge state or a charging state. When the first power supply terminal 111 (corresponding to Figure 2 P+) and the second power supply terminal 112 (corresponding to Figure 2 When the first power supply terminal 111 and the second power supply are connected to the power supply, it means that the main working circuit is in the charging state. The control unit 150 controls the first charging switch 1312 to be turned on, so that the first battery group 121 and the second battery group 122 supply power to the load. When the first power supply terminal 111 and the second power supply are connected to the power supply, it means that the main working circuit is in the charging state. The control unit 150 controls the first charging switch 1312 to be turned on, and the first battery group 121 and the second battery group 122 are charged simultaneously through the power supply.

[0042] In one embodiment, the control unit 150 is further used to switch the second switch unit 132 on and turn on the power conversion unit 140; so that the first battery pack 121 supplies power to the second battery pack 122 through the power conversion unit 140, and the second battery pack 122 provides power output through the first power terminal 111, or the external power input charges the second battery pack 122 through the first power terminal 111, and the second battery pack 122 charges the first battery pack 121 through the power conversion unit 140. Specifically, in the specific operation process of the battery system, the second switch unit 132 can be switched on by the control unit 150, and the power conversion unit 140 is turned on at the same time. When the battery system needs to be connected to a low power output platform, only the second battery pack 122 needs to provide output to obtain the required output voltage. Therefore, the control unit 150 needs to control the first switch unit 131 to be turned on according to the corresponding control level, and at this time, the second battery pack 122 forms a main working circuit with the first power terminal 111 and the second power terminal 112, and the first battery pack 121 is bypassed by the main working circuit. If the first power supply terminal 111 and the second power supply terminal 112 are connected to a load at this time, the load can be powered by the second battery pack 122. If the first power supply terminal 111 and the second power supply are connected to a power supply at this time, the second battery pack 122 can be charged by the power supply. Because only the second battery pack 122 is required to participate in the main circuit work at this time, the energy transfer between the first battery pack 121 and the second battery pack 122 can be performed as needed. When the second battery pack 122 is supplying power to the outside, in order to ensure the power supply of the second battery pack 122, the control unit 150 can control the power conversion unit 140 so that the output of the first battery pack 121 can supply power to the second battery pack 122 through the power conversion unit 140, so as to extend the power supply time of the second battery pack 122. When charging the second battery pack 122, in order to store energy, the control unit 150 can control the power conversion unit 140 to convert the input of the second battery pack 122 to charge the first battery pack 121.

[0043] Further, such as Figure 2As shown, the second switch unit 132 includes a second discharge switch 1321 and a second charge switch 1322; the control unit 150 is used to switch the second discharge switch 1321 on so that the second battery pack 122 provides power output through the first power supply terminal 111; or the control unit 150 is used to switch the second charge switch 1322 on so that the external power input charges the second battery pack 122 through the first power supply terminal 111. Specifically, in the second switch unit 132, the second discharge switch 1321 and the second charge switch 1322 are respectively used to control whether the main working circuit is in a discharge state or a charge state. When the first power supply terminal 111 and the second power supply terminal 112 are connected to a load, it means that the main working circuit is in a discharge state, and the control unit 150 controls the second discharge switch 1321 to be turned on so that the second battery pack 122 supplies power to the load. When the first power supply terminal 111 and the second power supply are connected to a power supply, it means that the main working circuit is in a charging state, and the control unit 150 controls the second charge switch 1322 to be turned on, and the second battery pack 122 is charged through the power supply.

[0044] In one embodiment, if Figure 2 and Figure 3 As shown, the power conversion unit 140 includes a bidirectional DCDC conversion circuit, that is, the energy transfer between the first battery pack 121 and the second battery pack 122 can be realized through the bidirectional DCDC conversion circuit.

[0045] In a specific embodiment, the specific circuit of the bidirectional DCDC conversion circuit may include a transformer 141, a primary bridge circuit 142 connected to the primary side of the transformer 141 and the first battery pack 121, a secondary bridge circuit 143 connected to the secondary side of the transformer 141 and the second battery pack 122, and a first drive circuit 144 connected to the primary bridge circuit 142, and a second drive circuit 145 connected to the secondary bridge circuit 143. The first drive circuit 144 and the second drive circuit 145 are connected to a control unit 150, and the control unit 150 controls the action of the first drive circuit 144 and the second drive circuit 145 by outputting a control level to realize the working process of the bidirectional DCDC conversion circuit. For example, the control unit 150 outputs a control level to enable the output of the first battery group 121 to power the second battery group 122 through the primary bridge circuit 142, the transformer 141 and the secondary bridge circuit 143, or the control unit 150 outputs a control level to enable the output of the second battery group 122 to power the first battery group 121 through the secondary bridge circuit 143, the transformer 141 and the primary bridge circuit 142. Figure 3As shown, the transformer 141 includes a transformer T1, a first end and a second end of the transformer T1 are connected to a secondary bridge circuit 143, and a third end and a fourth end of the transformer T1 are respectively connected to a primary bridge circuit 142. The primary bridge circuit 142 is composed of a MOS transistor D1, a MOS transistor D2, a MOS transistor D3, and a MOS transistor D4. The first drive circuit 144 outputs a PWM level according to the control level of the control unit 150 to control the working process of the primary bridge circuit 142. The secondary bridge circuit 143 is composed of a MOS transistor D5, a MOS transistor D6, a MOS transistor D7, and a MOS transistor B8. The second drive circuit 145 outputs a PWM level according to the control level of the control unit 150 to control the working process of the secondary bridge circuit 143.

[0046] In one embodiment, the first battery pack 121 includes a plurality of battery cells connected in series and a short circuit protection unit connected in series with the battery cells. Specifically, the first battery pack 121 is composed of a plurality of battery cells connected in series, and the required voltage is obtained by connecting the plurality of battery cells in series. Figure 2 As shown, the first battery pack 121 is composed of 4 battery cells connected in series. At the same time, the multiple battery cells are also connected in series with the short-circuit protection unit. This prevents the first end and the second end of the first battery pack 121 from being short-circuited when the first switch unit 131 and the second switch unit 132 are turned on at the same time, causing circuit damage. The short-circuit protection unit automatically opens when the first end and the second end of the first battery pack 121 are short-circuited and a large current occurs. In a specific embodiment, the short-circuit protection unit can be a fuse.

[0047] In one embodiment, the second battery pack 122 includes a plurality of battery cells connected in series. That is, the second battery pack 122 is formed by connecting a plurality of battery cells, such as obtaining a required voltage by connecting a plurality of battery cells in series. Figure 2 As shown, the second battery group 122 is composed of 16 battery cells connected in series.

[0048] In addition, a battery pack of the present invention includes the above battery system, that is, a battery pack is constructed, and the above battery system is arranged inside, and the same battery pack can be compatible with different power supply platforms through the battery pack. The battery pack can be connected to an external communication device through a communication unit to generate corresponding instructions to control the working process of the battery system through the external communication device. For example, the control unit 150 generates a corresponding control level according to the received instruction to control the corresponding unit action.

[0049] In addition, a battery system control method of the present invention is as follows: Figure 1As shown, the battery system includes: a first power supply terminal 111, a second power supply terminal 112, a first battery group 121, a second battery group 122, a first switch unit 131, a second switch unit 132 and a power conversion unit 140; the first end of the first battery group 121 is connected to the first power supply terminal 111 via the first switch unit 131, the second end of the first battery group 121 is connected to the first end of the second battery group 122 and then connected to the first power supply terminal 111 via the second switch unit 132, and the second end of the second battery group 122 is connected to the second power supply terminal 112; the power conversion unit 140 is connected to the first battery group 121 and the second battery group 122. The control method includes: switching the first switch unit 131 on and turning off the power conversion unit 140, so that the first battery group 121 and the second battery group 122 provide power output through the first power terminal 111, or allowing the external power input to charge the first battery group 121 and the second battery group 122 through the first power terminal 111; or switching the second switch unit 132 on and turning on the power conversion unit 140, so that the first battery group 121 supplies power to the second battery group 122 through the power conversion unit 140, and the second battery group 122 provides power output through the first power terminal 111, or allowing the external power input to charge the second battery group 122 through the first power terminal 111, and the second battery group 122 charges the first battery group 121 through the power conversion unit 140.

[0050] Specifically, the battery system is connected to a load or a power supply device through the first power supply terminal 111 and the second power supply terminal 112. The first battery group 121 and the second battery group 122 are connected in series. The power conversion unit 140 is connected between the first battery group 121 and the second battery group 122. In the specific working process, one of the first switch unit 131 and the second switch unit 132 is first controlled to be turned on, that is, only one of the first switch unit 131 and the second switch unit 132 is in a conducting state. When the first switch unit 131 is controlled to be turned on, the second switch unit 132 is set to be in a turned-off state, and the first power supply terminal 111 forms a main working circuit with the second power supply terminal 112 by connecting the first battery group 121 and the second battery group 122 in series. If the first power supply terminal 111 and the second power supply terminal 112 are connected to a load at this time, the load can be powered by the first battery group 121 and the second battery group 122. If the first power supply terminal 111 and the second power supply are connected to a power supply at this time, the first battery group 121 and the second battery group 122 can be charged simultaneously by the power supply. When the second switch unit 132 is controlled to be turned on, the first switch unit 131 is set to the off state. The first power supply terminal 111 forms a main working circuit with the second power supply terminal 112 through the second battery pack 122. If the first power supply terminal 111 and the second power supply terminal 112 are connected to a load at this time, the load can be powered by the second battery pack 122. If the first power supply terminal 111 and the second power supply are connected to a power supply at this time, the second battery pack 122 can be charged simultaneously by the power supply. At the same time, the working state of the power conversion unit 140 is controlled so that the power conversion unit 140 is in the off state or the working state. When the power conversion unit 140 is in the working state, the power conversion unit 140 can be controlled to convert the output of the first battery pack 121 into energy and then input it to the second battery pack 122, or the power conversion unit 140 can be controlled to convert the output of the second battery pack 122 into energy and then input it to the first battery pack 121.

[0051] In a specific embodiment, during the specific operation of the battery system, the first switch unit 131 can be switched on by controlling the switching, and the power conversion unit 140 can be turned off at the same time. When the battery system needs to be connected to a high power output platform, the first battery group 121 and the second battery group 122 need to provide output at the same time to obtain the required output voltage. Therefore, it is necessary to control the first switch unit 131 to be turned on, and the first battery group 121 and the second battery group 122 form a series connection relationship at this time, and form a main working circuit with the first power supply terminal 111 and the second power supply terminal 112. If the first power supply terminal 111 and the second power supply are connected to the load at this time, the load can be powered by the first battery group 121 and the second battery group 122. If the first power supply terminal 111 and the second power supply are connected to the power supply at this time, the first battery group 121 and the second battery group 122 can be charged simultaneously by the power supply. At this time, because the first battery group 121 and the second battery group 122 are both involved in the main working circuit, there is no need to transfer energy between the first battery group 121 and the second battery group 122, and the power conversion unit 140 is set to the off state.

[0052] In another specific embodiment, the second switch unit 132 can also be switched on by controlling the power conversion unit 140. For example, when the battery system needs to be connected to a low power output platform, only the second battery pack 122 needs to provide output to obtain the required output voltage. Therefore, it is necessary to control the first switch unit 131 to be turned on, at which time the second battery pack 122 forms a main working circuit with the first power supply terminal 111 and the second power supply terminal 112, and the first battery pack 121 is bypassed by the main working circuit. If the first power supply terminal 111 and the second power supply terminal 112 are connected to a load at this time, the load can be powered by the second battery pack 122. If the first power supply terminal 111 and the second power supply are connected to a power supply at this time, the second battery pack 122 can be charged by the power supply. Therefore, only the second battery pack 122 is needed to participate in the main circuit work at this time, and the energy transfer between the first battery pack 121 and the second battery pack 122 can be performed as needed. When the second battery pack 122 is supplying power to the outside, in order to ensure the power supply of the second battery pack 122, the power conversion unit 140 can be controlled so that the output of the first battery pack 121 can supply power to the second battery pack 122 through the power conversion unit 140, so as to extend the power supply time of the second battery pack 122. When charging the second battery pack 122, in order to store energy, the power conversion unit 140 can be controlled to convert the voltage of the input of the second battery pack 122 so as to charge the first battery pack 121.

[0053] In one embodiment, the first switch unit 131 includes a first discharge switch 1311 and a first charging switch 1312; the control method further includes: switching the first discharge switch 1311 on so that the first battery group 121 and the second battery group 122 provide power output through the first power supply terminal 111; or switching the first charging switch 1312 on so that the external power input charges the first battery group 121 and the second battery group 122 through the first power supply terminal 111. Specifically, in the first switch unit 131, the first discharge switch 1311 and the first charging switch 1312 are respectively used to control whether the main working circuit is in a discharge state or a charging state. When the first power supply terminal 111 and the second power supply terminal 112 are connected to a load, it means that the main working circuit is in a discharge state, and the first discharge switch 1311 is controlled to be on so that the first battery group 121 and the second battery group 122 supply power to the load. When the first power supply terminal 111 and the second power supply are connected to the power supply, it indicates that the main working circuit is in the charging state, and the first charging switch 1312 is controlled to be turned on, and the first battery pack 121 and the second battery pack 122 are charged simultaneously through the power supply.

[0054] In one embodiment, the second switch unit 132 includes a second discharge switch 1321 and a second charge switch 1322; the control method further includes: switching the second discharge switch 1321 on so that the second battery pack 122 provides power output through the first power supply terminal 111; or switching the second charge switch 1322 on so that the external power input charges the second battery pack 122 through the first power supply terminal 111. In the second switch unit 132, the second discharge switch 1321 and the second charge switch 1322 are respectively used to control whether the main working circuit is in a discharge state or a charge state. When the first power supply terminal 111 and the second power supply terminal 112 are connected to a load, it means that the main working circuit is in a discharge state, and the second discharge switch 1321 is controlled to be turned on so that the second battery pack 122 supplies power to the load. When the first power supply terminal 111 and the second power supply are connected to a power supply, it means that the main working circuit is in a charging state, and the second charge switch 1322 is controlled to be turned on to charge the second battery pack 122 through the power supply.

[0055] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A battery system, characterized in that: include: A first power supply terminal, a second power supply terminal, a first battery pack, a second battery pack, a first switch unit, a second switch unit, a power conversion unit and a control unit; The first end of the first battery pack is connected to the first power supply end via the first switch unit, the second end of the first battery pack is connected to the first end of the second battery pack and then connected to the first power supply end via the second switch unit, and the second end of the second battery pack is connected to the second power supply end; The first switch unit and the second switch unit are respectively connected to the control unit, and are used to receive a control level output by the control unit to switch one of the first switch unit and the second switch unit on; The power conversion unit is connected to the first battery pack, the second battery pack and the control unit, and is used to receive a control level output by the control unit to achieve energy transfer between the second battery pack and the first battery pack.

2. The battery system according to claim 1, characterized in that: The control unit is used to switch the first switch unit on and turn off the power conversion unit; So that the first battery pack and the second battery pack provide power output through the first power supply end; or external power input charges the first battery pack and the second battery pack through the first power supply end.

3. The battery system according to claim 2, characterized in that: The first switch unit includes a first discharging switch and a first charging switch; The control unit is used to switch the first discharge switch on so that the first battery pack and the second battery pack provide power output through the first power supply terminal; or The control unit is used to switch on the first charging switch so that an external power input charges the first battery pack and the second battery pack through the first power supply terminal.

4. The battery system according to claim 1, characterized in that: The control unit is further used to switch the second switch unit on and turn on the power conversion unit; So that the first battery group supplies power to the second battery group through the power conversion unit, and the second battery group provides power output through the first power supply terminal, or external power input charges the second battery group through the first power supply terminal, and the second battery group charges the first battery group through the power conversion unit.

5. The battery system according to claim 4, characterized in that: The second switch unit includes a second discharge switch and a second charge switch; The control unit is used to switch the second discharge switch on so that the second battery pack provides power output through the first power supply terminal; or The control unit is used to switch on the second charging switch so that the external power input charges the second battery pack through the first power terminal.

6. The battery system according to claim 1, characterized in that: The first battery pack includes a plurality of battery cells connected in series and a short-circuit protection unit connected in series with the battery cells, and / or the second battery pack includes a plurality of battery cells connected in series.

7. A battery pack, characterized in that: Comprising a battery system as claimed in any one of claims 1 to 6.

8. A battery system control method, characterized in that: The battery system comprises: a first power supply terminal, a second power supply terminal, a first battery pack, a second battery pack, a first switch unit, a second switch unit and a power conversion unit; The first end of the first battery pack is connected to the first power supply end via the first switch unit, the second end of the first battery pack is connected to the first end of the second battery pack and then connected to the first power supply end via the second switch unit, and the second end of the second battery pack is connected to the second power supply end; the power conversion unit connects the first battery pack and the second battery pack; The control method comprises: Switching the first switch unit on and turning off the power conversion unit so that the first battery pack and the second battery pack provide power output through the first power supply terminal, or allowing external power input to charge the first battery pack and the second battery pack through the first power supply terminal; or Switch the second switch unit on, and turn on the power conversion unit, so that the first battery group supplies power to the second battery group through the power conversion unit, and the second battery group provides a power output through the first power supply terminal, or enable an external power input to charge the second battery group through the first power supply terminal, and the second battery group charges the first battery group through the power conversion unit.

9. The battery system control method according to claim 8, characterized in that: The first switch unit includes a first discharge switch and a first charge switch; when the first switch unit is switched on, the control method further includes: Switching the first discharge switch on so that the first battery pack and the second battery pack provide power output through the first power supply terminal; or The first charging switch is switched on so that an external power input charges the first battery pack and the second battery pack through the first power terminal.

10. The battery system control method according to claim 8, characterized in that: The second switch unit includes a second discharge switch and a second charge switch; when the second switch unit is switched on, the control method further includes: Switching the second discharge switch on so that the second battery pack provides power output through the first power supply terminal; or The second charging switch is switched on so that the external power input charges the second battery pack through the first power terminal.

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