Battery circuit and vehicle

Abstract

The present application discloses a battery circuit and a vehicle, and relates to the field of vehicle technology. The battery circuit includes: a power supply end, a first battery pack, a second battery pack, a transformer unit, a first switch, a second switch, a ground terminal and a control unit, wherein: the positive electrode of the first battery pack is connected to the power supply end, the negative electrode of the first battery pack is connected to the positive electrode of the second battery pack; the negative electrode of the second battery pack is connected to the ground terminal; the first end of the first switch is connected to the power supply end, the second end of the first switch is connected to the first end of the second switch, and the control end of the first switch is connected to the first output end of the control unit; the second end of the second switch is connected to the ground terminal, and the control end of the second switch is connected to the second output end of the control unit; the transformer unit is connected between the negative electrode of the first battery pack and the second end of the first switch; the control unit controls the closing or opening of the first switch and the second switch according to the temperature of the first battery pack and the second battery pack and at least one of the temperature of the second battery pack.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and more specifically, to a battery circuit and a vehicle. Background Art

[0002] With the development of science and technology, electric vehicles are slowly replacing fuel vehicles. As the core of electric vehicles, batteries are usually composed of a single type of battery pack. That is to say, the energy density and power density of existing batteries are fixed. However, in different driving scenarios, electric vehicles have different requirements for battery energy density and power density. Therefore, in order to meet different energy density and power density requirements, a dual battery pack consisting of a power battery pack and an energy battery pack is proposed.

[0003] However, the battery temperature is an important parameter of the battery. How to control the dual battery pack consisting of a power battery pack and an energy battery pack according to the battery temperature has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] One object of the present application is to provide a new technical solution for battery circuits.

[0005] According to a first aspect of the present application, a battery circuit is provided, comprising: a power supply terminal, a first battery pack, a second battery pack of a type different from that of the first battery pack, a voltage transformation unit, a first switch, a second switch, a ground terminal, and a control unit, wherein:

[0006] The positive electrode of the first battery pack is connected to the power supply terminal, and the negative electrode of the first battery pack is connected to the positive electrode of the second battery pack;

[0007] The negative electrode of the second battery pack is connected to the ground terminal;

[0008] A first end of the first switch is connected to the power supply end, a second end of the first switch is connected to a first end of the second switch, and a control end of the first switch is connected to a first output end of the control unit;

[0009] The second end of the second switch is connected to the ground end, and the control end of the second switch is connected to the second output end of the control unit;

[0010] The voltage transformation unit is connected between the negative electrode of the first battery pack and the second end of the first switch;

[0011] The control unit is used to control the closing or opening of the first switch and the second switch according to the temperature of the first battery pack and the second battery pack and at least one of the temperature of the second battery pack.

[0012] Optionally, the control unit is specifically used for:

[0013] When the average temperature or the maximum temperature between the first battery pack and the second battery pack, the temperature of the first battery pack or the temperature of the second battery pack is less than a preset temperature, the first switch and the second switch are controlled to be closed or opened according to a first preset control rule, so that the first battery pack and the second battery pack are in a state of mutual charging;

[0014] When the average temperature or the maximum temperature between the first battery pack and the second battery pack, or any one of the temperature of the first battery pack or the temperature of the second battery pack is greater than or equal to the preset temperature, the first switch and the second switch are controlled to be closed or opened according to a second preset control rule so that the first battery pack and the second battery pack are in a state other than mutual charging.

[0015] Optionally, a deviation between the rated voltage of the first battery pack and the rated voltage of the second battery pack is less than a first preset range;

[0016] And / or, a deviation between a ratio of the capacity of the first battery pack to the capacity of the second battery pack and a ratio of the maximum discharge rate of the second battery pack to the maximum discharge rate of the first battery pack is less than a second preset range.

[0017] Optionally, the rated voltage of the first battery pack is the same as the rated voltage of the second battery pack;

[0018] And / or, a ratio between the capacity of the first battery pack and the capacity of the second battery pack is the same as a ratio between the maximum discharge rate of the second battery pack and the maximum discharge rate of the first battery pack.

[0019] Optionally, the first battery pack is a power type battery pack, and the second battery pack is an energy type battery pack;

[0020] Alternatively, the first battery pack is the energy-type battery pack, and the second battery pack is a power-type battery pack.

[0021] Optionally, the control unit includes: a subtractor, a control subunit, a PWM signal generating subunit and an inverter, wherein:

[0022] The first input terminal of the subtractor receives the current value of the first battery pack, the second input terminal of the subtractor receives the reference current value, and the output terminal of the subtractor is connected to the input terminal of the control subunit;

[0023] The first output terminal of the control subunit is connected to the input terminal of the PWM signal generation subunit;

[0024] A first output terminal of the PWM signal generating subunit is connected to the control terminal of the first switch, and a second output terminal of the PWM signal generating subunit is connected to the input terminal of the inverter;

[0025] The output terminal of the inverter is connected to the control terminal of the second switch.

[0026] Optionally, the first battery pack is a power type battery pack, the second battery pack is an energy type battery pack, and the battery circuit further includes: a filtering unit, wherein:

[0027] The first end of the filter unit is connected to the positive electrode of the first battery pack, the second end of the filter unit is connected to the power supply end, and the third end of the filter unit is connected to the negative electrode of the first battery pack.

[0028] Optionally, the filtering unit includes a first inductor and a first capacitor, wherein:

[0029] The first end of the first inductor is connected to the positive electrode of the first battery pack, and the second end of the first inductor is connected to the power supply end;

[0030] The first end of the first capacitor is connected to the first end of the first inductor, and the second end of the first capacitor is connected to the negative electrode of the first battery pack.

[0031] Optionally, the battery circuit further includes a first freewheeling unit and a second freewheeling unit, wherein:

[0032] The input end of the first freewheeling unit is connected to the second end of the first switch, and the output end of the first freewheeling unit is connected to the first end of the first switch;

[0033] An input end of the second freewheeling unit is connected to the second end of the second switch, and an output end of the second freewheeling unit is connected to the first end of the second switch.

[0034] Optionally, the first freewheeling unit is a first diode, and the second freewheeling unit is a second diode, wherein:

[0035] An anode of the first diode is connected to the second end of the first switch, and a cathode of the first diode is connected to the first end of the first switch;

[0036] An anode of the second diode is connected to the second end of the second switch; and a cathode of the second diode is connected to the first end of the second switch.

[0037] Optionally, the battery circuit further includes a voltage stabilization unit, wherein:

[0038] The voltage stabilizing unit is connected between the power supply terminal and the ground terminal.

[0039] Optionally, the voltage stabilizing unit is a second capacitor.

[0040] Optionally, the voltage transformation unit is a second inductor.

[0041] According to a second aspect of the present application, a vehicle is provided, the vehicle comprising a battery circuit as described in any one of the first aspects above.

[0042] In an embodiment of the present application, a battery circuit is provided, including: a power supply terminal, a first battery pack, a second battery pack of a different type from the first battery pack, a transformer unit, a first switch, a second switch, a ground terminal, and a control unit, wherein: the positive electrode of the first battery pack is connected to the power supply terminal, the negative electrode of the first battery pack is connected to the positive electrode of the second battery pack; the negative electrode of the second battery pack is connected to the ground terminal; the first end of the first switch is connected to the power supply terminal, the second end of the first switch is connected to the first end of the second switch, and the control end of the first switch is connected to the first output end of the control unit; the second end of the second switch is connected to the ground terminal, and the control end of the second switch is connected to the second output end of the control unit; the transformer unit is connected between the negative electrode of the first battery pack and the second end of the first switch; wherein the control unit is used to control the closing or opening of the first switch and the second switch according to at least one of the temperature of the first battery pack and the second battery pack and the temperature of the second battery pack. The battery circuit can realize the self-heating control of the dual battery pack composed of the first battery pack and the second battery pack according to the temperature of the battery.

[0043] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0045] Figure 1 This is a schematic diagram of a battery circuit provided in an embodiment of the present application. Figure 1 ;

[0046] Figure 2 It is a structural schematic diagram of a control unit provided in an embodiment of the present application;

[0047] Figure 3 is a simulation diagram of operating current of a first battery pack and a second battery pack provided in an embodiment of the present application;

[0048] Figure 4 This is a schematic diagram of a battery circuit provided in an embodiment of the present application. Figure 2 ;

[0049] Figure 5 This is a schematic diagram of a battery circuit provided in an embodiment of the present application. Figure 3 ;

[0050] Reference numerals:

[0051] 100 - battery circuit; 101 - power supply terminal; 102 - first battery pack; 103 - second battery pack;

[0052] 104-transformer unit; 1041-second inductor; 105-first switch; 106-second switch;

[0053] 107-ground terminal; 108-control unit; 1081-subtractor; 1082-control subunit;

[0054] 1083-PWM signal generating subunit; 1084-inverter;

[0055] 1085-switch disconnection signal generating subunit; 109-filtering unit;

[0056] 1091 - first inductor; 1092 - first capacitor; 110 - first freewheeling unit;

[0057] 1101-first diode; 111-second freewheeling unit; 1111-second diode;

[0058] 112 - voltage stabilizing unit; 1121 - second capacitor. DETAILED DESCRIPTION

[0059] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0060] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0061] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0062] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0063] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0064] The present application embodiment provides a battery circuit 100, such as Figure 1 As shown, the battery circuit 100 includes: a power supply terminal 101, a first battery pack 102, a second battery pack 103 of a different type from the first battery pack 102, a voltage transformation unit 104, a first switch 105, a second switch 106, a ground terminal 107 and a control unit 108, wherein:

[0065] The positive electrode of the first battery pack 102 is connected to the power supply terminal 101 , and the negative electrode of the first battery pack 102 is connected to the positive electrode of the second battery pack 103 ;

[0066] The negative electrode of the second battery pack 103 is connected to the ground terminal 107;

[0067] A first end of the first switch 105 is connected to the power supply end 101 , a second end of the first switch 105 is connected to a first end of the second switch 106 , and a control end of the first switch 105 is connected to a first output end of the control unit 108 ;

[0068] A second end of the second switch 106 is connected to the ground end 107 , and a control end of the second switch 106 is connected to a second output end of the control unit 108 ;

[0069] The voltage transformation unit 104 is connected between the negative electrode of the first battery pack 102 and the second end of the first switch 105;

[0070] The control unit 108 is used to control the closing or opening of the first switch 105 and the second switch 106 according to at least one of the temperature of the first battery pack 102 and the temperature of the second battery pack 103 .

[0071] In an embodiment of the present application, a battery circuit is provided, comprising: a power supply terminal, a first battery pack, a second battery pack of a different type from the first battery pack, a transformer unit, a first switch, a second switch, a ground terminal, and a control unit, wherein: the positive electrode of the first battery pack is connected to the power supply terminal, the negative electrode of the first battery pack is connected to the positive electrode of the second battery pack; the negative electrode of the second battery pack is connected to the ground terminal; the first end of the first switch is connected to the power supply terminal, the second end of the first switch is connected to the first end of the second switch, and the control end of the first switch is connected to the first output end of the control unit; the second end of the second switch is connected to the ground terminal, and the control end of the second switch is connected to the second output end of the control unit; the transformer unit is connected between the negative electrode of the first battery pack and the second end of the first switch; wherein the control unit is used to control the closing or opening of the first switch and the second switch according to at least one of the temperature of the first battery pack and the second battery pack and the temperature of the second battery pack. The battery circuit can realize the self-heating control of the dual battery pack composed of the first battery pack and the second battery pack according to the temperature of the battery.

[0072] In the embodiment of the present application, when the battery circuit 100 is in a discharging state, the power terminal 101 in the battery circuit 100 is used to connect to the power input terminal of the load, and the ground terminal 107 in the battery circuit 100 is used to connect to the ground terminal of the load. The load can be exemplarily a motor of an electric vehicle or a hybrid vehicle.

[0073] Alternatively, when the battery circuit 100 is in a charging state, the power terminal 101 in the battery circuit 100 is used to connect to the power output terminal of the charging device, and the ground terminal 107 in the battery circuit 100 is used to connect to the ground terminal of the charging device. The charging device can be exemplarily a charging pile, or a braking system of an electric vehicle or a hybrid vehicle.

[0074] In one embodiment of the present application, Figure 4 As shown, the voltage transformation unit 104 may be a second inductor 1041. Of course, the voltage transformation unit 104 may also be implemented in other ways.

[0075] In one embodiment of the present application, the inductance value of the second inductor 1041 may be set within a range of 2 to 1500 uH.

[0076] In the embodiment of the present application, when the transformer unit 104 is the second inductor 1041 , the transformer unit 104 has low cost and simple structure.

[0077] In one embodiment of the present application, the first switch 105 and the second switch 106 can be switching devices such as switch IC, MOSFET (English full name: Metal Oxide Semiconductor Field Effect Transistor; Chinese full name: Metal-Oxide Semiconductor Field Effect Transistor), IGBT (Insulated Gate Bipolar Transistor; Insulated Gate Bipolar Transistor) or SiC (Silicon Carbide).

[0078] It should be noted that, in the embodiment of the present application, the first switch 105 and the second switch 106 are switches of the same type. That is, when the control ends of both receive a high level, the first switch 105 and the second switch 106 are both closed or opened. And, when the control ends of both receive a low level, the first switch 105 and the second switch 106 are both opened or closed.

[0079] In the embodiment of the present application, the first battery pack 102 and the second battery pack 103 are of different types. Specifically, the first battery pack 102 is a power type battery pack, and the second battery pack 103 is an energy type battery pack. Alternatively, the first battery pack 102 is an energy type battery pack, and the second battery pack 103 is a power type battery pack.

[0080] In the embodiment of the present application, the power type battery pack is designated as a battery pack with high power density. The power density is designated as: the maximum power of energy transfer per unit weight or volume of the battery during charging and discharging. And in the embodiment of the present application, the voltage value of the power type battery pack can be set within the range of 100 to 1000V.

[0081] The energy type battery pack is a battery pack with high energy density. The energy density is defined as the energy stored in the battery per unit weight or volume. In the embodiment of the present application, the voltage value of the energy type battery pack can be set within the range of 100 to 1000V.

[0082] In the embodiment of the present application, there is no limitation on the specific types of the first battery pack 102 and the second battery pack 103 , which can improve the compatibility of the battery circuit 100 provided in the embodiment of the present application.

[0083] In the embodiment of the present application, the control unit 108 is used to control the closing or opening of the first switch 105 and the second switch 106 according to at least one of the temperature of the first battery pack 102 and the temperature of the second battery pack 103. The specific implementation can be as follows:

[0084] The first one is that when the average temperature or the maximum temperature between the first battery pack 102 and the second battery pack 103, the temperature of the first battery pack 102 or the temperature of the second battery pack 103 is less than a preset temperature, the first switch 105 and the second switch 106 are controlled to be closed or opened according to a first preset control rule, so that the first battery pack 102 and the second battery pack 103 are in a state of mutual charging.

[0085] In the embodiment of the present application, the temperatures of the first battery pack 102 and the second battery pack 103 are usually similar. Therefore, the temperature of any one of the second battery pack 102 and the second battery pack 103, the average temperature therebetween, or the maximum temperature therebetween can represent the temperature of the dual battery pack battery composed of the first battery pack 102 and the second battery pack 103.

[0086] In one example, the temperature of the first battery pack 102 can be calculated based on the resistance value of the internal resistor with a temperature coefficient in the first battery pack 102. Similarly, the temperature of the second battery pack 103 can be calculated based on the resistance value of the internal resistor with a temperature coefficient in the second battery pack 103.

[0087] It should be noted that the embodiment of the present application does not limit the manner in which the control unit 108 acquires the temperature of the first battery pack 102 and the temperature of the second battery pack 103 .

[0088] In the embodiment of the present application, the preset temperature refers to the lowest temperature at which the battery pack can work stably. If the temperature of any one of the second battery pack 102 and the second battery pack 103, the average temperature thereof, or the maximum temperature thereof is lower than the preset temperature, it means that the first battery pack 102 and the second battery pack 103 cannot work stably.

[0089] In one example, the preset temperature may be set to -10°C.

[0090] In the embodiment of the present application, the first preset control rule may be a rule for controlling the first battery pack 102 to discharge in the first time period to charge the second battery pack 103, and controlling the second battery pack 103 to discharge in the second time period to charge the first battery pack 102. The second time period is a time period adjacent to the first time period and located before or after the first time period. The first time period and the second time period have the same duration, which can be set based on experience.

[0091] Based on the above content, the first preset control rule is: perform on-off operation, wherein the on-off operation is: in the first sub-time period, control the first switch 105 to be closed and the second switch 106 to be opened; in the second sub-time period, control the first switch 105 to be opened and the second switch 106 to be closed; in the third sub-time period, control the first switch 105 to be opened and the second switch 106 to be closed. In the fourth sub-time period, control the first switch 105 to be closed and the second switch 106 to be opened; repeat the on-off operation.

[0092] The second sub-time period is a time period adjacent to the first time period and located after the first sub-time period. The durations corresponding to the first sub-time period and the second sub-time period can be set based on experience. And the first sub-time period and the second sub-time period constitute the first time period.

[0093] Correspondingly, the fourth sub-time period is a time period adjacent to the third time period and located after the third sub-time period. The durations corresponding to the third sub-time period and the fourth sub-time period can be set based on experience. And, the third sub-time period and the fourth sub-time period constitute the second time period.

[0094] In the embodiment of the present application, the first switch 105 is controlled to be closed and the second switch 106 is disconnected in the first sub-time period. At this time, the first battery pack 102 charges the transformer unit 104. In the second sub-time period, the first switch 105 is controlled to be disconnected and the second switch 106 is closed. At this time, the transformer unit 104 releases the stored electric energy to the second battery pack 103. That is, the transformer unit 104 realizes the boost function. Based on this, the first battery pack 102 can charge the second battery pack 103.

[0095] In the third sub-time period, the first switch 105 is controlled to be opened and the second switch 106 is closed. At this time, the second battery pack 103 charges the transformer unit 104. In the fourth sub-time period, the first switch 105 is controlled to be closed and the second switch 106 is opened. At this time, the transformer unit 104 releases the stored electric energy to the first battery pack 102. That is, the transformer unit 104 realizes the boost function. Based on this, the second battery pack 103 can charge the first battery pack 102.

[0096] In this embodiment, due to the internal resistance of the first battery pack 102 and the second battery pack 103, mutual charging can realize the self-heating of the temperature of the first battery pack 102 and the second battery pack 103 to be greater than or equal to the preset temperature. When the temperature of the first battery pack 102 and the second battery pack 103 is self-heated to be greater than or equal to the preset temperature, the first battery pack 102 and the second battery pack 103 can work stably.

[0097] The second type is that when the average temperature or the maximum temperature between the first battery pack 102 and the second battery pack 103, the temperature of the first battery pack 102 or the temperature of the second battery pack 103 is greater than or equal to the preset temperature, the first switch 105 and the second switch 106 are controlled to be closed or opened according to the second preset control rule, so that the first battery pack 102 and the second battery pack 103 are in a state other than mutual charging.

[0098] In the embodiment of the present application, the second preset control rule is a rule different from the first preset control rule. In one example, the second preset control rule may be to control both the first switch 105 and the second switch 106 to be disconnected.

[0099] In the embodiment of the present application, when the average temperature or the maximum temperature between the temperature of the first battery pack 102 and the temperature of the second battery pack 103, or any one of the temperature of the first battery pack 102 or the temperature of the second battery pack 103 is greater than or equal to the preset temperature, it indicates that the first battery pack 102 and the second battery pack 103 can work stably. At this time, the first switch 105 and the second switch 106 are controlled to be closed or opened according to the second preset control rule, so that the first battery pack 102 and the second battery pack 103 are in a state other than mutual charging, that is, no self-heating is performed. For example, the first switch 105 and the second switch 106 are both controlled to be open, so that the first battery pack 102 and the second battery pack 103 are connected in series to discharge externally.

[0100] In an embodiment of the present application, a battery circuit is provided, comprising: a power supply terminal, a first battery pack, a second battery pack of a different type from the first battery pack, a transformer unit, a first switch, a second switch, a ground terminal, and a control unit, wherein: the positive electrode of the first battery pack is connected to the power supply terminal, the negative electrode of the first battery pack is connected to the positive electrode of the second battery pack; the negative electrode of the second battery pack is connected to the ground terminal; the first end of the first switch is connected to the power supply terminal, the second end of the first switch is connected to the first end of the second switch, and the control end of the first switch is connected to the first output end of the control unit; the second end of the second switch is connected to the ground terminal, and the control end of the second switch is connected to the second output end of the control unit; the transformer unit is connected between the negative electrode of the first battery pack and the second end of the first switch; wherein the control unit is used to control the closing or opening of the first switch and the second switch according to at least one of the temperature of the first battery pack and the second battery pack and the temperature of the second battery pack. The battery circuit can realize the self-heating control of the dual battery pack composed of the first battery pack and the second battery pack according to the temperature of the battery.

[0101] In the embodiment of the present application, a deviation between the rated voltage U1 of the first battery pack 102 and the rated voltage U2 of the second battery pack 103 is smaller than a first preset range.

[0102] In the embodiment of the present application, the first preset range is the allowable range of the deviation between the rated voltage U1 of the first battery pack 102 and the rated voltage U3 of the second battery pack 103. When the deviation between the rated voltage U1 of the first battery pack 102 and the rated voltage U2 of the second battery pack 103 is less than the first preset range, it means that the rated voltage U1 of the first battery pack 102 and the rated voltage U2 of the second battery pack 103 are substantially the same.

[0103] In one embodiment of the present application, the first preset range may be 0.2*U1 or 0.2*U2. When the first preset range is 0.2*U1, 1.2*U1≥U2≥0.8*U1; when the first preset range is 0.2*U2, 1.2*U2≥U1≥0.8*U2.

[0104] It should be noted that the embodiment of the present application does not limit the specific value of the first preset range.

[0105] In the embodiment of the present application, when the deviation between the rated voltage U1 of the first battery pack 102 and the rated voltage U2 of the second battery pack 103 is less than the first preset range, efficient energy transfer can be achieved between the first battery pack 102 and the second battery pack 103. For example, efficient mutual charging between the first battery pack 102 and the second battery pack 103 can be achieved.

[0106] It should be noted that, usually, the sum of the rated voltage U1 of the first battery pack 102 and the rated voltage U2 of the second battery pack 103 is equal to the total voltage Uout required by the load, that is, U1+U2=Uout.

[0107] In one embodiment of the present application, the rated voltage U1 of the first battery pack 102 is the same as the rated voltage U2 of the second battery pack 103. In this way, the most efficient energy transfer between the first battery pack 102 and the second battery pack 103 can be achieved.

[0108] Based on the above, in one example, Uout=550V, on this basis, U1=U2=275V can be set.

[0109] In the embodiment of the present application, the ratio of the capacity Q1 of the first battery pack 102 to the capacity Q2 of the second battery pack 103 and the ratio of the maximum discharge rate X2 of the second battery pack 103 to the maximum discharge rate X1 of the first battery pack 102 are less than the second preset range.

[0110] The maximum discharge rate represents the ratio of the maximum discharge current of the battery pack to the battery capacity. For example, for a battery pack with a battery capacity of 10Ah, its maximum discharge current is 50A, and the maximum discharge rate is 50A / 10Ah=5C.

[0111] In the embodiment of the present application, the second preset range is the range of the deviation allowed between the ratio of the capacity Q1 of the first battery pack 102 to the capacity Q2 of the second battery pack 103, and the ratio of the maximum discharge rate X2 of the second battery pack 103 to the maximum discharge rate X1 of the first battery pack 102. In the case where the deviation of the ratio of the capacity Q1 of the first battery pack 102 to the capacity Q2 of the second battery pack 103, and the ratio of the maximum discharge rate X2 of the second battery pack 103 to the maximum discharge rate X1 of the first battery pack 102 is less than the second preset range, it means that the ratio of the capacity Q1 of the first battery pack 102 to the capacity Q2 of the second battery pack 103, and the ratio of the maximum discharge rate X2 of the second battery pack 103 to the maximum discharge rate X1 of the first battery pack 102 are substantially the same.

[0112] In one embodiment of the present application, the second preset range may exemplarily be ±0.5.

[0113] It should be noted that the embodiment of the present application does not limit the specific value of the second preset range.

[0114] In the embodiment of the present application, when the ratio between the capacity of the first battery pack 102 and the capacity of the second battery pack 103 and the ratio between the maximum discharge rate of the second battery pack 103 and the maximum discharge rate of the first battery pack 101 are less than the second preset range, the maximum discharge currents of the two batteries to the outside can be substantially the same. Based on this, for example, the two batteries can be connected in series and discharge stably to the outside.

[0115] It should be noted that, usually, the sum of the capacity Q1 of the first battery pack 102 and the capacity Q2 of the second battery pack 103 is equal to the total capacity Qnom required by the load, that is, Q1+Q2=Qnom.

[0116] In one embodiment of the present application, the ratio between the capacity Q1 of the first battery pack 102 and the capacity Q2 of the second battery pack 103 is the same as the ratio between the maximum discharge rate X2 of the second battery pack 103 and the maximum discharge rate X1 of the first battery pack 102. In this way, the maximum external discharge current of the two can be exactly the same.

[0117] Based on the above, in one example, Qnom=120Ah, on this basis, Q1=100Ah, Q2=20Ah, X1=1C, and X2=5C can be set.

[0118] In one embodiment of the present application, when the control unit 108 controls the closing or opening of the first switch 105 and the second switch 106 according to the first preset control rule, it can be achieved through a PWM signal. According to the PWM signal, the opening and closing of the first switch 105 and the second switch 106 are controlled, and the opening time and closing time of the first switch and the second switch 106 are controlled according to the duty cycle of the PWM signal.

[0119] In one embodiment of the present application, in order to implement the above PWM signal, as Figure 2 As shown, the control unit 108 includes: a subtractor 1081, a control subunit 1082, a PWM signal generating subunit 1083 and an inverter 1084, wherein:

[0120] A first input terminal of the subtractor 1081 receives the current value of the first battery pack 102 , a second input terminal of the subtractor 1081 receives the reference current value, and an output terminal of the subtractor 1081 is connected to an input terminal of the control subunit 1082 ;

[0121] The first output terminal of the control subunit 1082 is connected to the input terminal of the PWM signal generation subunit 1083;

[0122] A first output terminal of the PWM signal generating subunit 1083 is connected to the control terminal of the first switch 105 , and a second output terminal of the PWM signal generating subunit 1083 is connected to the input terminal of the inverter 1084 ;

[0123] An output terminal of the inverter 1084 is connected to a control terminal of the second switch 106 .

[0124] In the embodiment of the present application, a preset temperature is stored in the control subunit 1082, and the control subunit 108 is used to obtain the average temperature or maximum temperature between the temperature of the first battery pack 105 and the temperature of the second battery pack 106, the temperature of the first battery pack 102 or the temperature of the second battery pack 103.

[0125] In one embodiment of the present application, the control subunit 1082 may be exemplarily an MCU or a CPU, etc.

[0126] In the embodiment of the present application, the current value of the output current of the first battery pack 102 can be detected by a current value detection unit. After detecting the output current value of the first battery pack 102, the current value detection unit sends the current value to the first input terminal of the subtractor 1081.

[0127] In the embodiment of the present application, there is no limitation on the manner in which the subtractor 1081 receives the current value of the output current of the first battery pack 102 and the reference current value.

[0128] In the embodiment of the present application, the subtractor 1082 is used to calculate the difference between the current value of the first battery pack 102 and the reference current value. The reference current value is often a value belonging to a sine wave current or a square wave current. In one example, the frequency f of the sine wave current or the square wave current can range from 10 Hz to 2000 Hz, and the amplitude A can range from 5 to 200.

[0129] The control subunit 1082 is also used to generate a PWM signal generation instruction according to the calculation result of the subtractor 1081 when the average temperature or maximum temperature between the temperature of the first battery pack 105 and the temperature of the second battery pack 106, the temperature of the first battery pack 102 or the temperature of the second battery pack 103 is lower than a preset temperature, and output the PWM signal generation instruction to the PWM signal generation subunit 1083.

[0130] The PWM signal generating subunit 1083 is used to output a PWM signal with an adjustable duty cycle under the control of the control subunit 1082 .

[0131] The inverter 1084 is used to invert the level output by the PWM signal generating subunit 1083 .

[0132] In the embodiment of the present application, the PWM signal generated by the PWM signal generating subunit 1083 can control the first battery pack 102 to charge the second battery pack 103 when the reference current value is greater than 0. Correspondingly, when the reference current value is less than 0, the second battery pack 103 is controlled to charge the first battery pack 102.

[0133] In the embodiment of the present application, a control unit 108 with a simple structure is provided, so as to reduce the design difficulty of the battery circuit provided in the embodiment of the present application.

[0134] In one embodiment of the present application, taking the preset temperature as -10°C, the first battery pack 102 as a power type battery pack, the second battery pack 103 as an energy type battery pack, the reference current as a sine wave, the frequency f of the sine wave as 200 Hz, and the amplitude A of the sine wave as 30 as an example, the simulation results of the working current of the first battery pack 102 and the working current of the second battery pack 103 can be as follows: Figure 3 shown.

[0135] It should be noted that, in the embodiment of the present application, the subtractor 1081 can periodically receive the current value of the output current of the first battery pack 102. In this way, closed-loop negative feedback regulation can be implemented, thereby causing the duty cycle of the PWM signal generated by the PWM signal generation subunit 1083 to change, so as to more quickly achieve the self-heating of the temperature of the first battery pack 102 and the second battery pack 103 to be greater than or equal to the preset temperature.

[0136] In one embodiment of the present application, when the first battery pack 102 is a power type battery pack and the second battery pack 103 is an energy type battery pack, as shown in FIG. Figure 4 As shown, the battery circuit 100 provided in the embodiment of the present application further includes a filtering unit 109, wherein:

[0137] A first end of the filter unit 109 is connected to the positive electrode of the first battery pack 102 , a second end of the filter unit 109 is connected to the power supply terminal 101 , and a third end of the filter unit 109 is connected to the negative electrode of the first battery pack 102 .

[0138] In the embodiment of the present application, since the power battery pack is usually used when the electric vehicle or hybrid vehicle generates peak power (such as the discharge peak power generated during the traction process and the charging peak power generated during the braking process), it is not necessary to be used in other cases. Therefore, in other cases, the output current of the power battery pack is expected to be 0. In this case, the current ripple of the first battery pack 102 can be suppressed by setting the filter unit 109, so as to avoid the output current of the power battery pack as the first battery pack 102 fluctuating around 0. In this way, the high-frequency rapid charging and discharging of the first battery pack 102 can be avoided, thereby reducing the problem of reduced life of the first battery pack 102.

[0139] In one embodiment of the present application, Figure 5 As shown, the filtering unit 109 includes a first inductor 1091 and a first capacitor 1092, wherein:

[0140] A first end of the first inductor 1091 is connected to the positive electrode of the first battery pack 102 , and a second end of the first inductor 1091 is connected to the power supply end;

[0141] A first end of the first capacitor 1092 is connected to a first end of the first inductor 1091 , and a second end of the first capacitor 1092 is connected to a negative electrode of the first battery pack 102 .

[0142] Of course, filtering units 109 of other structures may also be used, which will not be described in detail in the embodiments of the present application.

[0143] In the embodiment of the present application, the first inductor 1091 is a filter inductor, and the value of the first inductor 1091 can be set in the range of 2 to 1500 uH. The first capacitor 1092 is a filter capacitor, and the value of the first capacitor 1092 can be set in the range of 2 to 1500 uF.

[0144] It should be noted that, when the first battery pack 102 has a filtering function, the first inductor 1091 and the first capacitor 1092 can be set to smaller values. For example, the first inductor 1091 is set to 2uH, and the first capacitor 1092 is set to 2uF.

[0145] Correspondingly, when the first battery pack 102 does not have a filtering function, the first inductor 1091 and the first capacitor 1092 can be set to larger values. For example, the first inductor 1091 is set to 1500uH, and the first capacitor 1092 is set to 1500uF.

[0146] In the embodiment of the present application, a filter unit 109 with a simple structure is provided, which can reduce the hardware cost, design difficulty and board area of ​​the battery circuit 100.

[0147] In one embodiment of the present application, Figure 4 As shown, the battery circuit 100 provided in the embodiment of the present application further includes a first freewheeling unit 110 and a second freewheeling unit 111, wherein:

[0148] An input end of the first freewheeling unit 110 is connected to the second end of the first switch 105 , and an output end of the first freewheeling unit 110 is connected to the first end of the first switch 105 ;

[0149] An input end of the second freewheeling unit 111 is connected to a second end of the second switch 106 , and an output end of the second freewheeling unit 111 is connected to a first end of the second switch 106 .

[0150] In the embodiment of the present application, at the initial moment when the second switch 106 is controlled to be closed and the first switch 105 is disconnected, it is usually impossible to control the first switch 105 to be disconnected immediately due to the influence of the freewheeling time and the action time of the first switch 105. This will cause a short circuit between the first switch 105 and the second switch 106 for a short time, and then cause the first battery pack 102 and the second battery pack 103 to burn out due to the short circuit.

[0151] In the embodiment of the present application, the second freewheeling unit 111 is provided to be connected in parallel to both ends of the second switch 106, and the freewheeling unit 111 performs freewheeling. In this way, the closing time of the second switch 106 can be delayed when the first switch 105 is controlled to be disconnected, thereby avoiding the problem of burning of the first battery pack 102 and the second battery pack 103.

[0152] Similarly, the first freewheeling unit 110 is provided to be connected in parallel to both ends of the first switch 105, and the freewheeling unit 110 performs freewheeling. In this way, the closing time of the first switch 105 can be delayed when the second switch 106 is controlled to be disconnected, thereby avoiding the problem of burning of the first battery pack 102 and the second battery pack 103.

[0153] In one embodiment of the present application, Figure 5 As shown, the first freewheeling unit 110 is a first diode 1101, and the second freewheeling unit 111 is a second diode 1111, wherein:

[0154] An anode of the first diode 1101 is connected to the second end of the first switch 105 , and a cathode of the first diode 1101 is connected to the first end of the first switch 105 ;

[0155] An anode of the second diode 1111 is connected to the second end of the second switch 106 ; and a cathode of the second diode 1111 is connected to the first end of the second switch 106 .

[0156] In the embodiment of the present application, a first freewheeling unit 110 and a second freewheeling unit 111 with a simple structure are provided, which can reduce the hardware cost, design difficulty and board area of ​​the battery circuit 100.

[0157] In one embodiment of the present application, Figure 4 As shown, the battery circuit 100 provided in the embodiment of the present application further includes a voltage stabilizing unit 112, wherein:

[0158] The voltage stabilizing unit 1121 is connected between the power terminal 101 and the ground terminal 107 .

[0159] In the embodiment of the present application, the voltage stabilizing unit 112 is used to filter out voltage fluctuations on the bus, that is, the line where the power supply terminal 101 of the battery circuit 100 is located, so as to stabilize the voltage provided to the load. On the other hand, it is used to reduce the negative impact of the voltage fluctuations jointly generated by the first battery pack 102 and the transformer unit 104 on the second battery pack 103.

[0160] In one embodiment of the present application, Figure 5 As shown, the voltage stabilizing unit 112 may be exemplarily a second capacitor 1121. Of course, the voltage stabilizing unit 112 may also be implemented in other ways.

[0161] In one embodiment of the present application, the second capacitor 1121 is a support capacitor, and the value of the second capacitor 1121 can be set in the range of 2 to 1500 uF.

[0162] In the embodiment of the present application, a voltage stabilizing unit 112 with a simple structure is provided, which can reduce the hardware cost, design difficulty and board area of ​​the battery circuit 100.

[0163] An embodiment of the present application further provides a vehicle, which includes a battery circuit 100 provided in any of the above embodiments.

[0164] In the embodiment of the present application, the vehicle is an electric vehicle or a hybrid vehicle.

[0165] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein. The scope of the present application is defined by the appended claims.

Claims

1. A battery circuit, characterized in that: include: A power supply terminal, a first battery pack, a second battery pack of a type different from the first battery pack, a transformer unit, a first switch, a second switch, a ground terminal, and a control unit, wherein: The positive electrode of the first battery pack is connected to the power supply terminal, and the negative electrode of the first battery pack is connected to the positive electrode of the second battery pack; The negative electrode of the second battery pack is connected to the ground terminal; A first end of the first switch is connected to the power supply end, a second end of the first switch is connected to a first end of the second switch, and a control end of the first switch is connected to a first output end of the control unit; The second end of the second switch is connected to the ground end, and the control end of the second switch is connected to the second output end of the control unit; The voltage transformation unit is connected between the negative electrode of the first battery pack and the second end of the first switch; The control unit is used to control the closing or opening of the first switch and the second switch according to at least one of the temperature of the first battery pack and the temperature of the second battery pack; The first battery pack is a power type battery pack, and the second battery pack is an energy type battery pack. The power type battery pack is used when peak power is generated during vehicle driving. The ratio of the capacity of the first battery pack to the capacity of the second battery pack and the ratio of the maximum discharge rate of the second battery pack to the maximum discharge rate of the first battery pack have a deviation less than a second preset range. The battery circuit also includes: a filter unit, a first end of the filter unit is connected to the positive electrode of the first battery pack, a second end of the filter unit is connected to the power supply end, and a third end of the filter unit is connected to the negative electrode of the first battery pack.

2. The battery circuit according to claim 1, characterized in that: The control unit is specifically used for: When the average temperature or the maximum temperature between the first battery pack and the second battery pack, the temperature of the first battery pack or the temperature of the second battery pack is less than a preset temperature, the first switch and the second switch are controlled to be closed or opened according to a first preset control rule, so that the first battery pack and the second battery pack are in a state of mutual charging; When the average temperature or the maximum temperature between the first battery pack and the second battery pack, or any one of the temperature of the first battery pack or the temperature of the second battery pack is greater than or equal to the preset temperature, the first switch and the second switch are controlled to be closed or opened according to a second preset control rule so that the first battery pack and the second battery pack are in a state other than mutual charging.

3. The battery circuit according to claim 1, characterized in that: A deviation between a rated voltage of the first battery pack and a rated voltage of the second battery pack is smaller than a first preset range.

4. The battery circuit according to claim 3, characterized in that: The rated voltage of the first battery pack is the same as the rated voltage of the second battery pack; And / or, a ratio between the capacity of the first battery pack and the capacity of the second battery pack is the same as a ratio between the maximum discharge rate of the second battery pack and the maximum discharge rate of the first battery pack.

5. The battery circuit according to claim 1, characterized in that: The control unit comprises: a subtractor, a control subunit, a PWM signal generating subunit and an inverter, wherein: The first input terminal of the subtractor receives the current value of the first battery pack, the second input terminal of the subtractor receives the reference current value, and the output terminal of the subtractor is connected to the input terminal of the control subunit; The first output terminal of the control subunit is connected to the input terminal of the PWM signal generation subunit; A first output terminal of the PWM signal generating subunit is connected to the control terminal of the first switch, and a second output terminal of the PWM signal generating subunit is connected to the input terminal of the inverter; The output end of the inverter is connected to the control end of the second switch.

6. The battery circuit according to claim 1, characterized in that: The filtering unit comprises a first inductor and a first capacitor, wherein: The first end of the first inductor is connected to the positive electrode of the first battery pack, and the second end of the first inductor is connected to the power supply end; The first end of the first capacitor is connected to the first end of the first inductor, and the second end of the first capacitor is connected to the negative electrode of the first battery pack.

7. The battery circuit according to claim 1, characterized in that: The battery circuit further includes a first freewheeling unit and a second freewheeling unit, wherein: The input end of the first freewheeling unit is connected to the second end of the first switch, and the output end of the first freewheeling unit is connected to the first end of the first switch; An input end of the second freewheeling unit is connected to the second end of the second switch, and an output end of the second freewheeling unit is connected to the first end of the second switch.

8. The battery circuit according to claim 7, characterized in that: The first freewheeling unit is a first diode, and the second freewheeling unit is a second diode, wherein: An anode of the first diode is connected to the second end of the first switch, and a cathode of the first diode is connected to the first end of the first switch; An anode of the second diode is connected to the second end of the second switch; and a cathode of the second diode is connected to the first end of the second switch.

9. The battery circuit according to claim 1, characterized in that: The battery circuit further includes a voltage stabilization unit, wherein: The voltage stabilizing unit is connected between the power supply terminal and the ground terminal.

10. The battery circuit according to claim 9, characterized in that: The voltage stabilizing unit is a second capacitor.

11. The battery circuit according to claim 1, characterized in that: The voltage transformation unit is a second inductor.

12. A vehicle, characterized in that: The vehicle comprises a battery circuit as claimed in any one of claims 1-11.

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