Power supply system and vehicle

Abstract

The utility model discloses a power supply system and a vehicle, the power supply system comprises a battery pack, the battery pack comprises a plurality of battery cells connected in series, a first equalization connection end is arranged between the middle point of the plurality of battery cells equally divided and the first end of the battery pack, and the first equalization connection end is suitable for being connected with the first end of a first type of electric equipment. And a second equalization connection end is arranged between the middle point where the plurality of battery cells are equally divided and the second end of the battery pack, and the second equalization connection end is suitable for being connected with the second end of the first type of electric equipment. The power supply system supplies power to the first electric equipment through the battery cells in the two half packs, voltage jump caused by only half pack power supply can be avoided, and stable power supply of the first type of electric equipment is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of battery management, in particular to a power supply system and a vehicle. Background Art

[0002] In the prior art, the multi-voltage system is connected to the half of the battery pack, that is, the half of the battery pack is used to supply power. In this way, when the charge and discharge states of the upper half and the lower half of the battery pack change, the voltage of the half pack will jump, which may cause the power supply of the multi-voltage system powered by the half pack to be unstable. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the utility model is to provide a power supply system, which can avoid voltage mutations occurring in half-pack power supply, making the power supply of electrical equipment more stable.

[0004] The second objective of the present invention is to provide a vehicle.

[0005] In order to solve the above problems, an embodiment of the first aspect of the utility model provides a power supply system, including: a battery pack, the battery pack including a plurality of battery cells connected in series, a first balancing connection terminal is provided between a midpoint of the plurality of battery cells and a first end of the battery pack, the first balancing connection terminal is suitable for connecting to a first end of a first type of electrical equipment, a second balancing connection terminal is provided between a midpoint of the plurality of battery cells and a second end of the battery pack, the second balancing connection terminal is suitable for connecting to a second end of the first type of electrical equipment.

[0006] According to the power supply system of the embodiment of the utility model, the balancing connection end is located in the two half packs, that is, some battery cells of the two half packs are used to jointly power the first type of electrical equipment. In this way, balanced power can be taken from the midpoint of the battery pack, which can avoid voltage mutations caused by only half-pack power supply, thereby ensuring the stability of power supply to the first type of electrical equipment.

[0007] In some embodiments, the first end of the battery pack is suitable for connecting to the first end of the second type of electrical equipment, and the second end of the battery pack is suitable for connecting to the second end of the second type of electrical equipment, wherein the electrical voltage of the second type of electrical equipment is greater than the electrical voltage of the first type of electrical equipment.

[0008] In some embodiments, a battery management circuit module, a first end of the battery management circuit module is connected to a first end of the battery pack, a second end of the battery management circuit module is connected to a second end of the battery pack, and a third end of the battery management circuit module is connected to a midpoint of a plurality of the battery cells to heat the battery pack.

[0009] In some embodiments, the number of cells between the midpoint of the cells and the first balancing connection end is M, the number of cells between the midpoint of the cells and the second balancing connection end is N, and M is equal to or unequal to N.

[0010] In some embodiments, the fourth end of the battery management circuit module is connected to the first balancing connection end, and the fifth end of the battery management circuit module is connected to the second balancing connection end, for balancing the power of the cells in the battery pack.

[0011] In some embodiments, the battery management circuit module includes: at least one inductor, the first end of each of the inductors being connected to the midpoint of a plurality of the battery cells in equal parts; at least one bridge arm circuit, the at least one bridge arm circuit being connected correspondingly to the at least one inductor, the first end of each of the bridge arm circuits being connected to the first end of the battery pack, the second end of each of the bridge arm circuits being connected to the second end of the battery pack, and the midpoint of each of the bridge arm circuits being connected to the second end of the corresponding inductor, for controlling the charging and discharging of the corresponding inductor to achieve heating and charge balancing of the battery pack.

[0012] In some embodiments, each of the bridge arm circuits includes: a first switch tube and a second switch tube, wherein the first end of the first switch tube is connected to the first end of the battery pack, the second end of the first switch tube is connected to the first end of the second switch tube, the second end of the second switch tube is connected to the second end of the battery pack, and the midpoint of the bridge arm circuit is between the second end of the first switch tube and the first end of the second switch tube.

[0013] In some embodiments, the battery management circuit module also includes: a first switch, wherein the first end of each of the inductors is connected to the midpoint of the battery cells divided equally through the first switch, and the first switch is used to control the heating function of the battery pack by the battery management circuit module.

[0014] In some embodiments, the battery management circuit module also includes: a first diode unit and a second diode unit, the output end of the first diode unit is connected to the first balancing connection end, the input end of the first diode unit is connected to the first end of each of the inductors, the input end of the first diode unit is also connected to the output end of the second diode unit, and the input end of the second diode unit is connected to the second balancing connection end, so as to achieve charge balancing of the battery cells in the battery pack.

[0015] In some embodiments, the battery management circuit module also includes: a second switch, wherein the input end of the first diode unit and the output end of the second diode unit are connected to the first end of each of the inductors through the second switch, and the second switch is used to control the battery management circuit module to switch on and off the battery balancing function of the battery cells in the battery pack.

[0016] In some embodiments, a battery pack includes 2W battery groups connected in series, each of the battery groups includes at least one battery cell, the midpoint of the 2W battery groups is the midpoint of the multiple battery cells, the W battery groups between the midpoint of the 2W battery groups and the first end of the battery pack are the first balancing connection ends, and the W battery groups between the midpoint of the 2W battery groups and the second end of the battery pack are the second balancing connection ends, wherein W is an even number.

[0017] A second aspect of the present invention provides a vehicle, comprising a first type of electrical equipment, a second type of electrical equipment, a controller and the power supply system described in the above embodiment.

[0018] According to the vehicle of the embodiment of the utility model, by adopting the power supply system of the above embodiment, power is evenly drawn from the midpoint of the battery pack, and the battery cells of the two half packs jointly power the first category of electrical equipment, which can avoid the voltage mutation caused by only half-pack power supply and ensure the stability of power supply to the first category of electrical equipment.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0021] Figure 1 is a circuit diagram of a power supply system provided by an embodiment of the present application;

[0022] Figure 2 is a circuit diagram of a power supply system provided by an embodiment of the present application;

[0023] Figure 3 is a circuit diagram of a power supply system provided by an embodiment of the present application;

[0024] Figure 4 is a circuit diagram of a better power supply system provided by an embodiment of the present application;

[0025] Figure 5 is a circuit diagram of a power supply system provided by an embodiment of the present application;

[0026] Figure 6 It is a circuit diagram of a balanced timing of a power supply system provided by an embodiment of the present application;

[0027] Figure 7 It is a circuit diagram of a balanced timing of a power supply system provided by an embodiment of the present application;

[0028] Figure 8 It is a circuit diagram of a balanced timing of a power supply system provided by an embodiment of the present application;

[0029] Fig. 9 It is a circuit diagram of a balanced timing of a power supply system provided by an embodiment of the present application;

[0030] Fig.10 It is a circuit diagram of a self-heating timing of a self-heating system provided by an embodiment of the present application;

[0031] Fig.11 It is a circuit diagram of a self-heating timing of a self-heating system provided by an embodiment of the present application;

[0032] Fig.12 It is a circuit diagram of a self-heating timing of a self-heating system provided by an embodiment of the present application;

[0033] Fig.13 It is a circuit diagram of a self-heating timing of a self-heating system provided by an embodiment of the present application;

[0034] Fig.14 It is a structural block diagram of a vehicle provided in one embodiment of the present application.

[0035] Reference numerals:

[0036] Power supply system 100; vehicle 200;

[0037] Battery pack 110; battery management circuit module 120; bridge arm circuit 130;

[0038] First balancing connection terminal 111; second balancing connection terminal 112; battery cell midpoint 113; second type electrical equipment 101; first type electrical equipment 102; first switch tube 131; second switch tube 132; bridge arm circuit midpoint 133; inductor 103; first switch 104; second switch 105; first diode unit 106; second diode unit 107; controller 201. DETAILED DESCRIPTION

[0039] The embodiments of the present utility model are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present utility model are described in detail below.

[0040] The first embodiment of the utility model provides a power supply system 100, such as Figure 1 As shown, the power supply system 100 includes: a battery pack 110 .

[0041] Among them, the battery pack 110 includes a plurality of battery cells connected in series, and a first balancing connection terminal 111 is provided between the midpoint of the plurality of battery cells and the first end of the battery pack 110, and the first balancing connection terminal 111 is suitable for connecting to the first end of the first type of electrical equipment 102, and a second balancing connection terminal 112 is provided between the midpoint of the plurality of battery cells and the second end of the battery pack 110, and the second balancing connection terminal 112 is suitable for connecting to the second end of the first type of electrical equipment 102.

[0042] In some embodiments, the first category of electrical equipment 102 may be electrical equipment powered by a variety of different low voltage supplies, for example, low voltage electrical equipment with an operating voltage of 12V or 24V.

[0043] Among them, the midpoint of multiple battery cells can be the midpoint position of multiple battery cells arranged in series, or the position divided equally according to the number of battery cells, or the midpoint position according to the distribution of power, so as to achieve balanced power extraction from the midpoint of the battery pack.

[0044] Specifically, the battery pack can be divided into two half packs from the center of the battery pack, that is, the midpoint of the battery pack cells. The first balancing connection terminal 111 and the second balancing connection terminal 112 are located in the two half packs, that is, power is evenly drawn from the midpoint of the battery pack, and the first category of electrical equipment is jointly powered by some of the cells in the two half packs. In this way, when the charging and discharging states of the upper half pack and the lower half pack change, for example, alternately, the state of the cells in the upper half pack that powers the first category of electrical equipment is opposite to the state of the cells in the lower half pack that powers the first category of electrical equipment. For example, when the cells in the upper half pack are charging, the cells in the lower half pack are in a discharging state. Therefore, the voltage and current changes of the cells in the two half packs that power the first category of electrical equipment can offset each other to a certain extent, avoiding voltage mutations of the cells in the two half packs that power the first category of electrical equipment, thereby improving the stability of power supply to the first category of electrical equipment.

[0045] According to the power supply system of the embodiment of the utility model, the balancing connection ends are respectively located in the two half-packs, that is, some battery cells of the two half-packs are used to jointly power the first category of electrical equipment. In this way, balanced power can be taken from the midpoint of the battery pack, which can avoid voltage mutations caused by only half-pack power supply, thereby ensuring the stability of power supply to the first category of electrical equipment.

[0046] Further, in some embodiments, the first end of the battery pack 110 is suitable for connecting to the first end of the second type of electrical equipment 101, and the second end of the battery pack 101 is suitable for connecting to the second end of the second type of electrical equipment 101, wherein the power voltage of the first type of electrical equipment 102 is less than the power voltage of the second type of electrical equipment 101, that is, the power voltage of the second type of electrical equipment is greater than the power voltage of the first type of electrical equipment. In an embodiment, the second type of electrical equipment 101 may be a high voltage electrical equipment, for example, a device with an operating voltage of 200V to 800V.

[0047] That is, in the embodiment of the utility model, the entire battery pack supplies power to the high-voltage electrical equipment. During the self-heating process, there is no sudden change in the voltage balance of the entire pack. Therefore, the stability of the high-voltage electrical equipment can be guaranteed, the power supply balance of each part of the battery pack self-heating process can be achieved, and the power supply of high and low voltage electrical equipment can be stable.

[0048] like Figure 1 As shown, the power supply system 100 further includes a battery management circuit module 120 .

[0049] The first end of the battery management circuit module 120 is connected to the first end of the battery pack 110 , the second end of the battery management circuit module is connected to the second end of the battery pack 110 , and the third end of the battery management circuit module 120 is connected to the midpoint 113 that bisects multiple battery cells to heat the battery pack 110 .

[0050] In some embodiments, the battery management module 120 may include a half-bridge circuit, an inductor, and a switch component, etc., which can achieve balanced control of various parts of the battery pack during the self-heating process of the battery pack.

[0051] Specifically, when the battery pack is self-heating, the battery management module 120 controls the alternating charge and discharge states of the upper and lower half packs of the battery pack. The utility model draws power evenly from the midpoint 113 of the battery cell of the battery pack 110. The first type of electrical equipment 102 is connected to the two half packs, that is, the first type of electrical equipment is jointly powered by some of the battery cells of the two half packs of the battery pack, and the second type of electrical equipment is connected to the two ends of the battery pack, that is, the entire pack supplies power to the second type of electrical equipment. During self-heating, when the battery cells in the upper half pack are in a charging state, the battery cells in the lower half pack are in a discharging state, and the battery cells that power the first type of electrical equipment include both the battery cells in the upper half pack and the battery cells in the lower half pack, thereby ensuring that during self-heating, the voltage fluctuations of the upper and lower half packs of the battery pack 110 are offset, thereby ensuring that the voltage of the multi-voltage system remains stable.

[0052] like Figure 2As shown, the upper half of the battery pack 110 may include the battery cells from the midpoint 113 of the battery cells to the first end of the battery pack 110, and the lower half of the battery pack 110 may be understood as the battery cells from the midpoint 113 of the battery cells to the second end of the battery pack 110; the battery cells in the first balancing connection terminal 111 and the second balancing connection terminal 112 together constitute a voltage source for the first type of electrical equipment 102, and when the power supply system 100 is self-heating, the voltage of the voltage source jointly constituted by the battery cells in the first balancing connection terminal 111 and the second balancing connection terminal 112 will remain stable.

[0053] In some embodiments, the number of cells between the midpoint of the plurality of cells and the first balancing connection end is M, the number of cells between the midpoint of the plurality of cells equally divided and the second balancing connection end is N, and M and N are equal or unequal.

[0054] Specifically, in order to ensure the voltage stability of the power supply system 100, the number of cells between the midpoint 113 of the multiple cells and the first balancing connection terminal 111 is M, and the number of cells between the midpoint 113 of the multiple cells and the second balancing connection terminal 112 is N, and M is equal to N; however, any system has a certain ability to resist voltage disturbances, and the voltage fluctuation allowable threshold of the power supply system 100 is set to ±U1. Assuming that all cells of the power system 100 have good consistency, the internal resistance of a single cell is R1, and the self-heating current is I1; then

[0055] I1*R1*|MN|≤U1; (Formula 1)

[0056] By conversion, |MN|≤U1 / (I1*R1). (Formula 2)

[0057] That is to say, the number of battery cells M and N may be different, and the difference in the number of battery cells can be estimated using the formula (Formula 2).

[0058] In some embodiments, Figure 1 As shown, the battery management circuit module 120 includes: a battery management circuit module fourth terminal and a battery management circuit module fifth terminal.

[0059] The fourth end of the battery management circuit module is connected to the first balancing connection end 110 , and the fifth end of the battery management circuit module is connected to the second balancing connection end 112 , for balancing the power of the cells in the battery pack.

[0060] In some embodiments, Figure 1 As shown, the battery management circuit module 120 includes: at least one inductor 103 and at least one bridge arm circuit 130 .

[0061] Among them, the first end of each inductor 103 is connected to the midpoint 113 that divides the multiple battery cells equally; at least one bridge arm circuit 130 is connected to at least one inductor 103 accordingly, the first end of each bridge arm circuit 130 is connected to the first end of the battery pack 110, the second end of each bridge arm circuit 130 is connected to the second end of the battery pack 110, and the midpoint 133 of each bridge arm circuit is connected to the second end of the corresponding inductor 103, which is used to control the charging and discharging of the corresponding inductor to achieve heating and power balancing of the battery pack.

[0062] In some embodiments, the inductor 103 may be a special inductor element, or may be an element such as a motor winding, a wire coil, etc. that can be equivalent to an inductor.

[0063] Specifically, self-heating means that the bridge arm circuit 130 outside the battery pack 110 and the inductor 103 generate an oscillating current, which generates heat on the internal resistance of the battery pack 110 to complete the heating of the battery. In addition, the charge and discharge of the inductor 103 can achieve the balance of the battery pack.

[0064] In some embodiments, Figure 1 As shown, each bridge arm circuit 130 includes: a first switch tube 131 and a second switch tube 132 .

[0065] In some embodiments, the switch tubes in the bridge arm circuit 130 , such as the first switch tube 131 and the second switch tube 132 , may be IGBTs or MOSFETs, that is, the switch tubes in the bridge arm circuit may be fully controlled power electronic switches.

[0066] Among them, the first end of the first switch tube 131 is connected to the first end of the battery pack 110, the second end of the first switch tube 131 is connected to the first end of the second switch tube 132, the second end of the second switch tube 132 is connected to the second end of the battery pack 110, and there is a midpoint 133 of the bridge arm circuit between the second end of the first switch tube 131 and the first end of the second switch tube 131.

[0067] In some embodiments, Figure 1 As shown, the battery management circuit module 120 further includes: a first switch 104 .

[0068] The first end of each inductor 103 is connected to a midpoint 113 that divides the plurality of battery cells in half through a first switch 104 . The first switch 104 is used to control the heating function of the battery pack 110 by the battery management circuit module 120 .

[0069] Specifically, when the battery pack 110 needs to be heated, the first switch 104 in the battery management circuit module 120 is closed, and the bridge arm circuit 130 and the inductor 103 generate an oscillating current. The oscillating current is transmitted to the battery pack 110 through the first switch 104, generating heat on the internal resistance of the battery pack 110 itself, thereby completing the heating of the battery.

[0070] In some embodiments, Figure 1 As shown, the battery management circuit module 120 further includes: a first diode unit 106 and a second diode unit 107 .

[0071] Among them, the output end of the first diode unit 106 is connected to the first balancing connection end 111, the input end of the first diode unit 106 is connected to the first end of each inductor 103, the input end of the first diode unit 106 is also connected to the output end of the second diode unit 107, and the input end of the second diode unit 107 is connected to the second balancing connection end 112, so as to achieve power balancing of the battery cells in the battery pack.

[0072] Specifically, since the diode has the characteristic of unidirectional conduction, when the power supply system 100 heats the battery pack, the first diode unit 106 and the second diode unit 107 are in a reverse cutoff state, so no current flows; when power balancing is required, the current can pass through the first diode unit 106 and the second diode unit 107, and the power supply system 100 performs power balancing through diodes.

[0073] In some embodiments, Figure 1 As shown, the battery management circuit module 120 further includes: a second switch 105 .

[0074] Among them, the input end of the first diode unit 106 and the output end of the second diode unit 107 are connected to the first end of each inductor 103 through the second switch 105, and the second switch is used to control the battery management circuit module 120 to switch on the battery cell in the battery pack 110.

[0075] Specifically, when the power supply system 100 needs to turn on the power balancing function, the second switch 105 is closed and the first switch 104 is opened. At this time, the power supply system 100 only performs power balancing, and the current can pass through the first diode unit 106 and the second diode unit 107. The power supply system 100 performs power balancing through diodes.

[0076] For example, Figure 2As shown, the cells in the battery pack 110 are connected in series to supply power to the first power-consuming device 101 together; the cells between the midpoint 113 of the multiple cells and the first balancing connection terminal 111 and the cells between the midpoint 113 of the multiple cells and the second balancing connection terminal 112 supply power to the second power-consuming device 102; this results in the charge of the cells between the midpoint 113 of the multiple cells and the first balancing connection terminal 111 and the cells between the midpoint 113 of the multiple cells and the second balancing connection terminal 112 being lower than that of other cells that do not supply power to the second power-consuming device 102. In order to solve this problem, a balancing solution is proposed, such as Figure 3 As shown. Figure 2 On the basis of the above, we add a bridge arm circuit 130, an inductor 103, a first diode 106, and a second diode 107. The switch in the bridge arm circuit 130 can be an insulated gate bipolar transistor or a metal oxide semiconductor field effect transistor, which can be a fully controlled power electronic switch; the inductor 103 can be a special inductor element, or a motor winding, a wire coil, etc., which can be equivalent to an inductor element.

[0077] In addition, the present invention proposes a new balanced and compatible self-heating solution to form a power supply system 100, which only requires Figure 3 Based on the above, two new function conversion switches are added, such as Figure 1 As shown, the first switch 104 and the second switch 105, when self-heating is required, the first switch 104 is closed and the second switch 105 is opened; when balancing is required, the second switch 105 is closed and the first switch 104 is opened.

[0078] for Figure 1 The power supply system 110 shown can be optimized to form Figure 6 The power supply system 110 shown can remove the second switch 105 and only retain the first switch 104; when self-heating is required, the first switch 104 is closed, and the system completes the self-heating function. At this time, the diode is in a reverse cut-off state, so no current flows, and the balancing function cannot be turned on; when the balancing function needs to be implemented, the first switch 104 is disconnected, and the system starts balancing through the diode, and uses the reverse cut-off characteristics of the diode to achieve the switching of the balancing and self-heating functions.

[0079] In some embodiments of the present invention, the battery management circuit module 120 may use an inductor 103 such as Figure 1 , 2 As shown in FIG. 4 , multiple inductors 103 may also be used. Figure 5 As shown, the battery management circuit module 120 can use a bridge arm circuit 130 such as Figure 1 , 2 As shown in FIG. 4, multiple bridge arm circuits 130 may also be used, for example, Figure 5 shown.

[0080] For example, the inductor 103 is used as a three-phase motor winding. Figure 5 As shown, the power supply system 100 includes a battery pack 110 , three bridge arm circuits 130 , three motor windings 103 , a first switch 104 , a first diode unit 106 and a second diode unit 107 .

[0081] Since the two half packs of cells that supply power to the first type of electrical equipment not only supply power to the first type of electrical equipment, but also supply power to the second type of electrical equipment, the power of the cells between the first balancing connection end and the second balancing connection end will be lower than the power of the cells between the first balancing connection end and the first end of the battery pack and lower than the power of the cells between the second balancing connection end and the second end of the battery pack, resulting in unbalanced power of the cells in the battery pack. The power supply system 100 of the embodiment of the utility model can achieve power balancing of the cells in each part of the battery pack.

[0082] Specifically, Figure 5 For example, a battery pack including four cells is used. When power balancing is to be performed, the first switch 104 is disconnected, and the balancing sequence is as follows:

[0083] Time series 1: Figure 6 As shown, the first switch tube 131 of the bridge arm circuit 130 is closed and the second switch tube 132 is disconnected. The battery cell discharges to store energy in the three-phase motor winding 103. Specifically, the current flows from the positive electrode of the battery pack 110 through the first switch tube 131 of the bridge arm circuit 130 to the motor winding 103, passes through the first diode unit 106, and returns to the negative electrode of the battery cell. It is assumed that in this process, the energy released by the battery cell to charge the motor winding 103 is W1. W1=U1*I1. Among them, U1 is the voltage from the first balancing connection terminal 111 in the upper half of the battery pack 110 to the first end of the battery pack at this time, and I1 is the current flowing in the circuit at this time.

[0084] Time series 2: Figure 7As shown, the first switch tube 131 of the bridge arm circuit 130 is disconnected, and the second switch tube 132 is closed or disconnected (when disconnected, the current flows through the parasitic reverse diode of the second switch tube 132). The motor winding 103 releases the stored energy to the battery cell between the first balancing connection end and the second end of the battery pack. In detail, the energy stored in the motor winding 103 charges the battery cell through the first diode unit 106, and the current returns to the motor winding 103 through the second switch tube 132 of the bridge arm circuit 130. In this process, the motor winding 103 releases its stored W1 energy to the battery cell between the first balancing connection end and the second end of the battery pack. In this process, W1=U2*I2. And because U2=3*U1. Therefore, I1=3*I2. Among them, U2 is the voltage between the first balancing connection end 111 and the second end of the battery pack, and I2 is the current in the dotted line loop shown in the figure at this time.

[0085] Time series 3: Figure 8 As shown, the first switch tube 131 of the bridge arm circuit 130 is disconnected, and the second switch tube 132 is closed. The battery cell discharges to store energy in the motor winding 103. In general, the current flows from the positive electrode of the battery cell through the second diode unit 107 to the motor winding 103, and then passes through the second switch tube 132 of the bridge arm circuit 130, and returns to the negative electrode of the battery cell between the second end of the battery pack and the second balancing connection end 112. It is assumed that in this process, the energy released by the battery cell to charge the motor winding is W1. W1=U1*I1.

[0086] Time series 4: Fig. 9 , the first switch tube 131 of the bridge arm circuit 130 is disconnected or closed (when disconnected, the current flows through the second diode unit 107 parasitic on the first switch tube 131), and the second switch tube 132 is closed. The motor winding 103 releases the stored energy to the battery cell between the first end of the battery pack and the second balancing connection terminal 112. In detail, the energy stored in the motor winding 103 charges the battery cell between the first end of the battery pack and the second balancing connection terminal 112 through the first switch tube 131 of the bridge arm circuit 130, and the charging current returns to the motor winding 103 through the second diode unit 107. In this process, the motor winding 103 releases its stored energy W1 to the battery cell, and in this process, W1=U2*I2. And because U2=3*U1. Therefore, I1=3*I2.

[0087] In the above four processes, the battery cells between the first end of the battery pack and the first balancing connection terminal 111 and the battery cells between the second end of the battery pack and the second balancing connection terminal 112 release 2*I2 of electricity, while the battery cells between the first balancing connection terminal 111 and the midpoint of the battery pack and the battery cells between the second balancing connection terminal 111 and the midpoint of the battery pack absorb 2*I2 of current. The above four processes are repeated, so that the battery cells that power the first type of electrical equipment can be charged by other battery cells that do not participate in powering the first type of electrical equipment until the battery cells in each part of the battery pack, such as Figure 5 The charge of the four cells is balanced.

[0088] Reference Figure 4 For the power supply system shown, the four timings of self-heating are:

[0089] Time series 1: Fig.10 As shown, the upper bridge is closed, the lower bridge is disconnected, and the first switch is closed. The upper half pack charges the inductor, and the inductor stores energy. At the same time, the voltage of the upper half pack drops. Assuming that the discharge current at this time is I, then Uo=Uocv-I*R, where Uocv is the open circuit voltage of the battery, R is the internal resistance of the battery, and Uo is the output voltage of the battery. Then the dropped voltage ΔU=I*R.

[0090] Time series 2: Fig.11 As shown, the upper bridge is disconnected, the lower bridge is closed, and the first switch is closed. The inductor releases the stored energy to the lower half package, and the voltage of the lower half package rises. At this time, the voltage of the lower half package rises ΔU = I*R.

[0091] Time series 3: Fig.12 , the upper bridge is disconnected, the lower bridge is closed, and the first switch is closed. The lower half pack charges the inductor, and the inductor stores energy. At the same time, the voltage of the lower half pack drops. At this time, the voltage drop of the lower half pack ΔU=I*R.

[0092] Time series 4: Fig.13 , the upper bridge is closed, the lower bridge is disconnected, and the first switch is closed. The inductor releases the stored energy to the upper half package, and the voltage of the upper half package rises. At this time, the voltage of the upper half package rises ΔU=I*R.

[0093] Through timing 1 to timing 4, the current passes through the bridge arm and the inductor, charging and discharging back and forth between the upper half pack and the lower half pack to complete the heating of the battery. At the same time, it can be seen that the voltage of the upper half pack and the lower half pack has been fluctuating due to the continuous charging and discharging of the current. The total voltage of the bus = the voltage of the upper half pack + the voltage of the lower half pack. When the discharge voltage of the upper half pack drops, the charging voltage of the lower half pack rises, and the total voltage of the battery pack remains unchanged. Therefore, the voltage of electrical equipment connected to the DC bus, such as the second type of electrical equipment, will not be affected by the self-heating function. In the present application, the voltage of electrical equipment hung on the half-pack, such as the first type of electrical equipment, will not be affected. Since the first type of electrical equipment is connected to the two half-packs and is powered by some of the battery cells in the two half-packs, the power supply of the first type of electrical equipment = the voltage of some of the battery cells in the upper half-pack + the voltage of some of the battery cells in the lower half-pack. During the alternating change of the charging and discharging states of the upper half-pack and the lower half-pack, the battery cells in the upper half-pack are charged when the battery cells in the lower half-pack are discharged. Conversely, the battery cells in the upper half-pack are discharged when the battery cells in the lower half-pack are charged. The power change value ΔU is equal, so that the voltage changes of the upper and lower half-packs can be offset. The above four self-heating timing processes are taken as one cycle. In this way, the increased voltage of the upper half-pack and the decreased voltage of the lower half-pack in one cycle, as well as the decreased voltage of the upper half-pack and the increased voltage of the lower half-pack in one cycle offset each other. Therefore, the total voltage supplied to the first type of electrical equipment in one cycle remains unchanged.

[0094] Therefore, the power supply system of the present application can avoid a large jump in the power supply of the first category of electrical equipment, thereby ensuring the normal operation of the first category of electrical equipment.

[0095] In some embodiments, the battery pack includes 2W battery groups connected in series, each battery group includes at least one battery cell, the midpoint of the 2W battery groups is the midpoint of multiple battery cells, the W battery groups between the midpoint of the 2W battery groups and the first end of the battery pack are the first balancing connection ends, and the W battery groups between the midpoint of the 2W battery groups and the second end of the battery pack are the second balancing connection ends, where W is an even number.

[0096] Specifically, Figure 2 As shown, the battery pack 110 includes 2W battery packs connected in series, each battery pack includes at least one battery cell, W is an even number, for example, W can be 2, 4, 6, etc., and the corresponding battery packs are 4, 8 and 12 groups. The battery pack between the midpoint 113 of the battery cell and the first end of the battery pack is equal to the battery pack between the midpoint 113 of the battery cell and the second end of the battery pack, that is, the battery pack is divided equally according to the midpoint 113 of the battery cell.

[0097] As for the battery cells for powering the first type of electrical equipment, preferably, the number of battery cells in the two half-packs is the same. In actual applications, the power supply system 100 has a certain ability to resist voltage disturbances, and the number of battery cells in the two half-packs only needs to satisfy the relationship (Formula 2) mentioned above, that is, to ensure that the voltages from the two balancing connection ends to the midpoint 113 of the battery cells are almost equal.

[0098] The second aspect of the utility model provides a vehicle, such as Fig.14 As shown, the vehicle 200 includes: a second-category electric user 101 , a first-category electric user 102 , a controller 201 and a power supply system 100 .

[0099] The power supply system 100 may be connected to the second-category power-consuming equipment 101 and the first-category power-consuming equipment 102 respectively, and the controller 201 is connected to the power supply system 100 to achieve self-heating of the battery pack and power balance of each part of the battery pack.

[0100] According to the vehicle of the embodiment of the utility model, by adopting the power supply system of the above embodiment, electricity is evenly drawn from the midpoint of the battery pack, and the electricity of the two half packs is used to jointly power the first category of electrical equipment. When the battery pack self-heats, sudden changes in the power supply to the first category of electrical equipment can be avoided, thereby ensuring the stability of the power supply.

[0101] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example.

[0102] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A power supply system, characterized in that: include: A battery pack, the battery pack comprising a plurality of battery cells connected in series, a first balancing connection terminal being provided between a midpoint of the plurality of battery cells and a first end of the battery pack, the first balancing connection terminal being suitable for connection to a first end of a first type of electrical equipment, and a second balancing connection terminal being provided between a midpoint of the plurality of battery cells and a second end of the battery pack, the second balancing connection terminal being suitable for connection to a second end of the first type of electrical equipment.

2. The power supply system according to claim 1, characterized in that: The first end of the battery pack is suitable for connecting to the first end of a second type of electrical equipment, and the second end of the battery pack is suitable for connecting to the second end of the second type of electrical equipment, wherein the power voltage of the second type of electrical equipment is greater than the power voltage of the first type of electrical equipment.

3. The power supply system according to claim 2, characterized in that: The power supply system further comprises: A battery management circuit module, wherein a first end of the battery management circuit module is connected to a first end of the battery pack, a second end of the battery management circuit module is connected to a second end of the battery pack, and a third end of the battery management circuit module is connected to a midpoint of a plurality of battery cells to heat the battery pack.

4. The power supply system according to claim 1, characterized in that: The number of cells between the midpoint of the cells equally divided and the first balancing connection end is M, the number of cells between the midpoint of the cells equally divided and the second balancing connection end is N, and M is equal to or unequal to N.

5. The power supply system according to claim 3, characterized in that: The fourth end of the battery management circuit module is connected to the first balancing connection end, and the fifth end of the battery management circuit module is connected to the second balancing connection end, for balancing the power of the cells in the battery pack.

6. The power supply system according to claim 5, characterized in that: The battery management circuit module comprises: at least one inductor, wherein a first end of each of the inductors is connected to a midpoint that is equally divided by the plurality of battery cores; At least one bridge arm circuit, the at least one bridge arm circuit is connected correspondingly to the at least one inductor, the first end of each bridge arm circuit is connected to the first end of the battery pack, the second end of each bridge arm circuit is connected to the second end of the battery pack, and the midpoint of each bridge arm circuit is connected to the second end of the corresponding inductor, for controlling the charging and discharging of the corresponding inductor to achieve heating and charge balancing of the battery pack.

7. The power supply system according to claim 6, characterized in that: Each of the bridge arm circuits comprises: A first switch tube and a second switch tube, wherein the first end of the first switch tube is connected to the first end of the battery pack, the second end of the first switch tube is connected to the first end of the second switch tube, the second end of the second switch tube is connected to the second end of the battery pack, and the midpoint of the bridge arm circuit is between the second end of the first switch tube and the first end of the second switch tube.

8. The power supply system according to claim 6, characterized in that: The battery management circuit module also includes: A first switch, wherein the first end of each of the inductors is connected to a midpoint of the battery cells divided equally through the first switch, and the first switch is used to control the heating function of the battery pack by the battery management circuit module.

9. The power supply system according to claim 8, characterized in that: The battery management circuit module also includes: A first diode unit and a second diode unit, wherein the output end of the first diode unit is connected to the first balancing connection end, the input end of the first diode unit is connected to the first end of each of the inductors, the input end of the first diode unit is also connected to the output end of the second diode unit, and the input end of the second diode unit is connected to the second balancing connection end, so as to realize charge balancing of the battery cells in the battery pack.

10. The power supply system according to claim 9, characterized in that: The battery management circuit module also includes: A second switch, the input end of the first diode unit and the output end of the second diode unit are connected to the first end of each of the inductors through the second switch, and the second switch is used to control the battery management circuit module to switch on and off the battery cell balance function in the battery pack.

11. The power supply system according to any one of claims 1 to 10, characterized in that: The battery pack includes 2W battery groups connected in series, each of the battery groups includes at least one battery cell, the midpoint of the 2W battery groups is the midpoint of the multiple battery cells, the W battery groups between the midpoint of the 2W battery groups and the first end of the battery pack are the first balancing connection ends, and the W battery groups between the midpoint of the 2W battery groups and the second end of the battery pack are the second balancing connection ends, wherein W is an even number.

12. A vehicle, characterized in that: It comprises a first-category electrical equipment, a second-category electrical equipment, a controller and the power supply system according to any one of claims 1-11.

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