Power supply system and vehicle

Abstract

A power supply system (100), comprising a battery pack (110). The battery pack comprises a plurality of battery cells (140) connected in series; a first balancing connection terminal (111) is provided between a midpoint (113) evenly dividing the plurality of battery cells and a first end of the battery pack, and the first balancing connection terminal is adapted to be connected to a first end of a first-type electric device (102); a second balancing connection terminal (112) is provided between the midpoint evenly dividing the plurality of battery cells and a second end of the battery pack, and the second balancing connection terminal is adapted to be connected to a second end of the first-type electric device (102). Also disclosed is a vehicle. Power is extracted in a balanced manner from the midpoint of the battery pack, and the battery cells in the two halves of the battery pack together supply power to the first-type electric device, thereby avoiding sudden change of voltage caused by power supply by only one half of the battery pack, and ensuring the stability of power supply to the first-type electric device.

Description

Power supply system and vehicles

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application No. 202421198534.5, filed on May 29, 2024, entitled "Power Supply System and Vehicle", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of battery management technology, and in particular to a power supply system and vehicle. Background Technology

[0004] In existing technology, multi-voltage systems are connected to half of the battery pack, meaning they are powered through the half of the battery pack. Therefore, when the charging and discharging states of the upper and lower halves of the battery pack change, the voltage of the half-pack will fluctuate, potentially leading to instability in the power supply of the multi-voltage system powered by the half-pack.

[0005] Public content

[0006] This disclosure aims to at least address one of the technical problems existing in the prior art. To this end, one object of this disclosure is to provide a power supply system that can avoid voltage fluctuations caused by partial power supply, thereby making the power supply to electrical equipment more stable.

[0007] The second objective of this disclosure is to propose a vehicle.

[0008] To address the aforementioned problems, a first aspect of this disclosure provides a power supply system including a battery pack. The battery pack includes a plurality of cells connected in series. A first equalization connection terminal is provided between the midpoint of the plurality of cells and a first end of the battery pack. The first equalization connection terminal is adapted to be connected to a first end of a first type of electrical device. A second equalization connection terminal is provided between the midpoint of the plurality of cells and a second end of the battery pack. The second equalization connection terminal is adapted to be connected to a second end of the first type of electrical device.

[0009] According to the power supply system of this disclosure embodiment, the equalization connection terminal is located in the two half-packs, that is, the first type of electrical equipment is powered by a portion of the battery cells in the two half-packs. In this way, power can be drawn equally from the midpoint of the battery pack, which can avoid voltage surges that occur when only half-packs are powered, and ensure the stability of the power supply to the first type of electrical equipment.

[0010] In some embodiments, the first end of the battery pack is adapted to be connected to the first end of the second type of electrical device, and the second end of the battery pack is adapted to be connected to the second end of the second type of electrical device, wherein the voltage of the second type of electrical device is greater than the voltage of the first type of electrical device.

[0011] In some embodiments, a battery management circuit module has a first terminal connected to a first terminal of the battery pack, a second terminal connected to a second terminal of the battery pack, and a third terminal connected to the midpoint of a plurality of equally spaced battery cells to heat the battery pack.

[0012] In some embodiments, the number of cells between the midpoint of the plurality of cells and the first equalization connection terminal is M, and the number of cells between the midpoint of the plurality of cells and the second equalization connection terminal is N, wherein M and N may be equal or unequal.

[0013] In some embodiments, the fourth terminal of the battery management circuit module is connected to the first equalization connection terminal, and the fifth terminal of the battery management circuit module is connected to the second equalization connection terminal, for performing power equalization on the cells in the battery pack.

[0014] In some embodiments, the battery management circuit module includes at least one inductor, with a first end of each inductor connected to the midpoint of a plurality of equally spaced battery cells; at least one bridge arm circuit, which is correspondingly connected to the at least one inductor, with a first end of each bridge arm circuit connected to the first end of the battery pack, a second end of each bridge arm circuit connected to the second end of the battery pack, and the midpoint of each bridge arm circuit connected to the second end of the corresponding inductor, for controlling the charging and discharging of the corresponding inductor to achieve heating and power balancing of the battery pack.

[0015] In some embodiments, each of the bridge arm circuits includes a first switch and a second switch, a first end of the first switch is connected to a first end of the battery pack, a second end of the first switch is connected to a first end of the second switch, a second end of the second switch is connected to a second end of the battery pack, and the bridge arm circuit has a midpoint between the second end of the first switch and the first end of the second switch.

[0016] In some embodiments, the battery management circuit module further includes a first switch, wherein a first end of each inductor is connected to the midpoint of the plurality of cells through the first switch, and the first switch is used to control the on / off switching of the heating function of the battery pack by the battery management circuit module.

[0017] In some embodiments, the battery management circuit module further includes a first diode unit and a second diode unit. The output terminal of the first diode unit is connected to the first balancing connection terminal, the input terminal of the first diode unit is connected to the first terminal of each inductor, the input terminal of the first diode unit is also connected to the output terminal of the second diode unit, and the input terminal of the second diode unit is connected to the second balancing connection terminal, so as to achieve power balancing of the cells in the battery pack.

[0018] In some embodiments, the battery management circuit module further includes a second switch, wherein the input terminal of the first diode unit and the output terminal of the second diode unit are both connected to the first terminal of each inductor through the second switch, and the second switch is used to control the switching of the battery management circuit module on the power balancing function of the cells in the battery pack.

[0019] In some embodiments, the battery pack includes 2W battery groups connected in series, each battery group including at least one of the battery cells, the midpoint of the 2W battery groups being equally divided is the midpoint of the plurality of battery cells being equally divided, the W battery groups between the midpoint of the 2W battery groups being equally divided and the first end of the battery pack are the first equalization connection terminals, and the W battery groups between the midpoint of the 2W battery groups being equally divided and the second equalization connection terminals are the second equalization connection terminals, wherein W is an even number.

[0020] A second aspect of this disclosure provides a vehicle including a first type of electrical equipment, a second type of electrical equipment, a controller, and a power supply system according to the above embodiments.

[0021] According to the vehicle of the present disclosure, by adopting the power supply system of the above embodiment, power is drawn evenly from the midpoint of the battery pack, and the first type of electrical equipment is powered by two half-pack cells. This can avoid voltage surges that occur when only half-pack is used for power supply, and ensure the stability of power supply to the first type of electrical equipment.

[0022] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0023] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 is a circuit diagram of a power supply system provided in an embodiment of this application;

[0025] Figure 2 is a circuit diagram of a power supply system provided in one embodiment of this application;

[0026] Figure 3 is a circuit diagram of a power supply system provided in one embodiment of this application;

[0027] Figure 4 is a circuit diagram of a superior power supply system provided in an embodiment of this application;

[0028] Figure 5 is a circuit diagram of a power supply system provided in one embodiment of this application;

[0029] Figure 6 is a circuit diagram of the power supply system balancing timing provided in one embodiment of this application;

[0030] Figure 7 is a circuit diagram of the power supply system balancing timing provided in one embodiment of this application;

[0031] Figure 8 is a circuit diagram of the power supply system balancing timing provided in one embodiment of this application;

[0032] Figure 9 is a circuit diagram of the power supply system balancing timing provided in one embodiment of this application;

[0033] Figure 10 is a circuit diagram showing the self-heating timing of a self-heating system provided in an embodiment of this application;

[0034] Figure 11 is a circuit diagram showing the self-heating timing of a self-heating system provided in an embodiment of this application;

[0035] Figure 12 is a circuit diagram showing the self-heating timing of a self-heating system provided in an embodiment of this application;

[0036] Figure 13 is a circuit diagram showing the self-heating timing of a self-heating system provided in an embodiment of this application;

[0037] Figure 14 is a structural block diagram of a vehicle provided in one embodiment of this application.

[0038] Reference numerals: Power supply system 100; Vehicle 200; Battery pack 110; Battery management circuit module 120; Bridge arm circuit 130; Battery cell 140; First equalization connection terminal 111; Second equalization connection terminal 112; Midpoint of the battery cell bisector 113; Second type of electrical equipment 101; First type of electrical equipment 102; First switching transistor 131; Second switching transistor 132; Midpoint of the bridge arm circuit 133; Inductor 103; First switch 104; Second switch 105; First diode unit 106; Second diode unit 107; Controller 201. Detailed Implementation

[0039] The embodiments of this disclosure are described in detail below, and the embodiments described with reference to the accompanying drawings are exemplary.

[0040] The first aspect of this disclosure provides a power supply system 100, as shown in FIG1, which includes a battery pack 110.

[0041] The battery pack 110 includes a plurality of cells 140 connected in series. The midpoint 113 of the plurality of cells is connected to the first end of the battery pack 110 and has a first equalization connection end 111. The first equalization connection end 111 is adapted to be connected to the first end of the first type of electrical equipment 102. The midpoint 113 of the plurality of cells is connected to the second end of the battery pack 110 and has a second equalization connection end 112. The second equalization connection end 112 is adapted to be connected to the second end of the first type of electrical equipment 102.

[0042] In some embodiments, the first type of electrical equipment 102 can be a variety of low-voltage powered electrical equipment, such as low-voltage electrical equipment with operating voltages of 12V and 24V.

[0043] The midpoint 113, where multiple cells are evenly distributed, can be the midpoint of multiple cells 140 connected in series, the midpoint of the distribution of cells 140, or the midpoint of the distribution of charge, so as to achieve balanced power intake from the midpoint of the battery pack.

[0044] Specifically, the battery pack can be divided into two halves from the center of the battery pack, which is the midpoint 113 where the battery cells are evenly divided. The first equalization connection terminal 111 and the second equalization connection terminal 112 are located in the two halves, that is, power is drawn evenly from the midpoint of the battery pack. The battery cells in the two halves jointly supply power to the first type of electrical device 102. In this way, when the charging and discharging states of the upper and lower halves change, for example, when they change alternately, the state of the battery cells 140 in the upper half supplying power to the first type of electrical device 102 is opposite to the state of the battery cells 140 in the lower half supplying power to the first type of electrical device 102. For example, when the battery cells 140 in the upper half are charging, the battery cells 140 in the lower half are discharging. Thus, the voltage and current changes of the battery cells 140 in the two halves supplying power to the first type of electrical device 102 can cancel each other out to a certain extent, avoiding voltage sudden changes in the battery cells 140 in the two halves supplying power to the first type of electrical device 102 and improving the stability of the power supply to the first type of electrical device 102.

[0045] According to the power supply system of this disclosure embodiment, the equalization connection terminals are located in the two half-packs respectively, that is, the first type of electrical device 102 is powered by a portion of the battery cells 140 of the two half-packs. In this way, power can be drawn equally from the midpoint of the battery pack, which can avoid voltage surges that occur when only half-packs are powered, and ensure the stability of the power supply to the first type of electrical device 102.

[0046] Furthermore, in some embodiments, the first end of the battery pack 110 is adapted to be connected to the first end of the second type of electrical device 101, and the second end of the battery pack 101 is adapted to be connected to the second end of the second type of electrical device 101, wherein the voltage of the first type of electrical device 102 is lower than the voltage of the second type of electrical device 101, that is, the voltage of the second type of electrical device 101 is higher than the voltage of the first type of electrical device 102. In embodiments, the second type of electrical device 101 can be a high-voltage electrical device, for example, a device with an operating voltage of 200V to 800V.

[0047] That is, in this embodiment of the disclosure, 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 intake of each part of the battery pack can be balanced during the self-heating process, and the power supply of high and low voltage electrical equipment can be stabilized.

[0048] As shown in Figure 1, the power supply system 100 also 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 120 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 of the multiple cells to heat the battery pack 110.

[0050] In some embodiments, the battery management module 120 may include a half-bridge circuit, an inductor 103, and a switching 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, during battery pack self-heating, the battery management module 120 controls the alternating charging and discharging states of the upper and lower halves of the battery pack. This disclosure draws power evenly from the midpoint 113 of the battery cells in the battery pack 110. A first type of electrical device 102 is connected to both halves, meaning it is powered by a portion of the cells 140 from both halves of the battery pack. A second type of electrical device 101 is connected to both ends of the battery pack, meaning the entire pack powers the second type of electrical device 101. During self-heating, while the cells 140 in the upper half are charging, the cells 140 in the lower half are discharging. The cells 140 supplying power to the first type of electrical device 102 include both the upper and lower halves, thus ensuring that voltage fluctuations in the upper and lower halves of the battery pack 110 cancel each other out during self-heating, thereby maintaining voltage stability in the multi-voltage system.

[0052] As shown in Figure 2, the upper half of the battery pack 110 may include the battery cells 140 from the midpoint 113 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 140 from the midpoint 113 to the second end of the battery pack 110. The battery cells 140 in the first equalization connection terminal 111 and the second equalization connection terminal 112 together constitute the voltage source of the first type of electrical equipment 102. When the power supply system 100 is self-heating, the voltage of the voltage source constituted by the battery cells 140 in the first equalization connection terminal 111 and the second equalization connection terminal 112 will remain stable.

[0053] In some embodiments, the number of cells 140 between the midpoint 113 of the plurality of cells and the first equalization connection end 111 is M, and the number of cells 140 between the midpoint 113 of the plurality of cells and the second equalization connection end 112 is N, where M and N may be equal or unequal.

[0054] Specifically, to ensure voltage stability in the power supply system 100, the number of cells 140 between the midpoint 113 (where multiple cells are evenly divided) and the first balancing connection terminal 111 is M, and the number of cells 140 between the midpoint 113 and the second balancing connection terminal 112 is N, where M and N are equal. However, any system has a certain ability to resist voltage disturbances, so the allowable voltage fluctuation threshold for the power supply system 100 is set to ±U1. Assuming good consistency among all cells in the power supply system 100, the internal resistance of a single cell 140 is R1, and the self-heating current is I1, then...

[0055] I1*R1*|MN|≤U1; (Equation 1)

[0056] Let's convert it: |MN|≤U1 / (I1*R1). (Equation 2)

[0057] In other words, the number of cells M and N can be different, and the difference in the number of cells 140 can be estimated using the formula (Equation 2).

[0058] In some embodiments, as shown in FIG1, the battery management circuit module 120 includes a fourth terminal and a fifth terminal of the battery management circuit module 120.

[0059] The fourth terminal of the battery management circuit module 120 is connected to the first equalization connection terminal 111, and the fifth terminal of the battery management circuit module 120 is connected to the second equalization connection terminal 112, which is used to perform power equalization on the cells 140 in the battery pack.

[0060] In some embodiments, as shown in FIG1, the battery management circuit module 120 includes at least one inductor 103 and at least one bridge arm circuit 130.

[0061] In this configuration, the first end of each inductor 103 is connected to the midpoint 113 of the multiple battery cells; at least one bridge arm circuit 130 is connected to at least one inductor 103, 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 103 to achieve heating of the battery pack and equalization of power.

[0062] In some embodiments, the inductor 103 can be a dedicated inductor element, or it can be a motor winding, wire coil, or other element that can be equivalent to an inductor.

[0063] Specifically, self-heating involves the external bridge arm circuit 130 of the battery pack 110 generating an oscillating current with the inductor 103. This oscillating current generates heat across the internal resistance of the battery pack 110, thus heating the battery. Furthermore, the charging and discharging of the inductor 103 enables balanced charge distribution within the battery pack.

[0064] In some embodiments, as shown in FIG1, each bridge arm circuit 130 includes: a first switching transistor 131 and a second switching transistor 132.

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

[0066] The first end of the first switch transistor 131 is connected to the first end of the battery pack 110, the second end of the first switch transistor 131 is connected to the first end of the second switch transistor 132, the second end of the second switch transistor 132 is connected to the second end of the battery pack 110, and the second end of the first switch transistor 131 and the first end of the second switch transistor 131 have a midpoint 133 of their respective bridge arm circuits.

[0067] In some embodiments, as shown in FIG1, the battery management circuit module 120 further includes a first switch 104.

[0068] The first end of each inductor 103 is connected to the midpoint 113 of the multiple cells 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, thus completing the heating of the battery pack.

[0070] In some embodiments, as shown in FIG1, the battery management circuit module 120 further includes a first diode unit 106 and a second diode unit 107.

[0071] The output terminal of the first diode unit 106 is connected to the first equalization connection terminal 111, the input terminal of the first diode unit 106 is connected to the first terminal of each inductor 103, the input terminal of the first diode unit 106 is also connected to the output terminal of the second diode unit 107, and the input terminal of the second diode unit 107 is connected to the second equalization connection terminal 112, so as to achieve power equalization of the cells 140 in the battery pack.

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

[0073] In some embodiments, as shown in FIG1, the battery management circuit module 120 further includes a second switch 105.

[0074] The input terminal of the first diode unit 106 and the output terminal of the second diode unit 107 are both connected to the first terminal of each inductor 103 through the second switch 105. The second switch 105 is used to control the power balancing function of the battery management circuit module 120 on the cells 140 in the battery pack 110.

[0075] Specifically, when the power supply system 100 needs to activate the power balancing function, the second switch 105 is closed and the first switch 104 is open. At this time, the power supply system 100 only performs power balancing. 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 the diodes.

[0076] For example, as shown in Figure 2, when the battery cells 140 in the battery pack 110 are connected in series to supply power to the second type of electrical device 101, the cells 140 between the midpoint 113 and the first balancing connection terminal 111, and the cells 140 between the midpoint 113 and the second balancing connection terminal 112, supply power to the first type of electrical device 102. This results in the charge of the cells 140 between the midpoint 113 and the first balancing connection terminal 111, and the cells 140 between the midpoint 113 and the second balancing connection terminal 112, being lower than that of the other cells 140 that do not supply power to the first type of electrical device 102. To solve this problem, a balancing scheme is proposed, as shown in Figure 3. Based on Figure 2, 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, and it can be a fully controlled power electronic switch; the inductor 103 can be a dedicated inductor element, or it can be a motor winding, wire coil, or other element that can be equivalent to an inductor.

[0077] In addition, this disclosure proposes a new balanced and compatible self-heating scheme to form a power supply system 100. It only requires the addition of two function switching switches based on Figure 3, as shown in Figure 1, namely 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 open; when balanced heating is required, the second switch 105 is closed and the first switch 104 is open.

[0078] The power supply system 110 shown in Figure 1 can be optimized to form the power supply system 110 shown in Figure 6. The second switch 105 can be removed, leaving only 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 the reverse cutoff state, so no current flows, and the equalization function cannot be turned on. When the equalization function is required, the first switch 104 is opened, and the system starts equalization through the diode. The reverse cutoff characteristic of the diode is used to switch between equalization and self-heating functions.

[0079] In some embodiments of this disclosure, the battery management circuit module 120 may employ one inductor 103 (e.g., as shown in Figures 1, 2, and 4) or multiple inductors 103 (e.g., as shown in Figure 5). The battery management circuit module 120 may employ one bridge arm circuit 130 (e.g., as shown in Figures 1, 2, or 4) or multiple bridge arm circuits 130 (e.g., as shown in Figure 5).

[0080] For example, taking the multiplexed three-phase motor winding as an example, as shown in Figure 5, 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] Because the two half-packed cells 140 supplying power to the first type of electrical device 102 also supply power to the second type of electrical device 101, the charge level of the cell 140 between the first balancing connection terminal 111 and the second balancing connection terminal 112 is lower than that of the cell 140 between the first balancing connection terminal 111 and the first end of the battery pack 110, and also lower than that of the cell 140 between the second balancing connection terminal 112 and the second end of the battery pack 110, resulting in an imbalance in the charge level of the cells 140 in the battery pack 110. The power supply system 100 of this embodiment can achieve charge balance among the cells 140 in each part of the battery pack.

[0082] Specifically, taking the battery pack 110 in Figure 5, which includes four cells 140, as an example, when power balancing is required, the first switch 104 is turned off, and the balancing sequence is as follows:

[0083] Timing 1: As shown in Figure 6, the first switch 131 of the bridge arm circuit 130 is closed, and the second switch 132 is open. Cell 140 discharges to store energy for the three-phase motor winding 103. Specifically, current flows from the positive terminal of battery pack 110, through the first switch 131 of the bridge arm circuit 130, to the motor winding 103, through the first diode unit 106, and back to the negative terminal of the cell. In this process, the energy released by cell 140 to charge the motor winding 103 is set to W1, where W1 = U1 * I1. Here, U1 is the voltage from the first equalization connection terminal 111 in the upper half of battery pack 110 to the first terminal of the battery pack, and I1 is the current flowing through the circuit at this time.

[0084] Timing 2: As shown in Figure 7, the first switch 131 of the bridge arm circuit 130 is open, and the second switch 132 is either closed or open (when open, current flows through the parasitic reverse diode of the second switch 132). The motor winding 103 releases the stored energy to the cell 140 between the first balancing connection terminal and the second terminal of the battery pack 110. Specifically, the energy stored in the motor winding 103 charges the cell 140 through the first diode unit 106, and the current returns to the motor winding 103 through the second switch 132 of the bridge arm circuit 130. During this process, the motor winding 103 releases its stored energy W1 to the cell 140 between the first balancing connection terminal 111 and the second terminal of the battery pack 110. In this process, W1 = U2 * I2. Since U2 = 3 * U1, I1 = 3 * I2. Where U2 is the voltage between the first balancing connection terminal 111 and the second terminal of the battery pack 110, and I2 is the current in the dashed circuit shown in the figure at this time.

[0085] Timing 3: As shown in Figure 8, the first switch 131 of the bridge arm circuit 130 is open, and the second switch 132 is closed. Cell 140 discharges to store energy for the motor winding 103. Generally, the current flows from the positive terminal of cell 140 through the second diode unit 107 to the motor winding 103, then through the second switch 132 of the bridge arm circuit 130, and back to the negative terminal of cell 140 between the second end of the battery pack 110 and the second equalization connection terminal 112. In this process, the energy released by cell 140 to charge the motor winding is set to W1, where W1 = U1 * I1.

[0086] Timing 4: As shown in Figure 9, the first switch 131 of the bridge arm circuit 130 is either open or closed (when open, current flows through the second diode unit 107 parasitic on the first switch 131), and the second switch 132 is closed. The motor winding 103 releases the stored energy to the cell 140 between the first end and the second equalization connection end 112 of the battery pack 110. Specifically, the energy stored in the motor winding 103 charges the cell 140 between the first end and the second equalization connection end 112 of the battery pack 110 through the first switch 131 of the bridge arm circuit 130, and the charging current returns to the motor winding 103 through the second diode unit 107. During this process, the motor winding 103 releases its stored energy W1 to the cell 140. In this process, W1 = U2 * I2. Since U2 = 3 * U1, I1 = 3 * I2.

[0087] In the four processes described above, the cells 140 between the first end of the battery pack 110 and the first balancing connection 111, and the cells 140 between the second end of the battery pack 110 and the second balancing connection 112, release 2*I2 of electricity. Meanwhile, the cells 140 between the first balancing connection 111 and the midpoint of the battery pack 110, and the cells between the second balancing connection 111 and the midpoint of the battery pack 110, absorb 2*I2 of current. These four processes are repeated cyclically, allowing other cells 140 that do not supply power to the first type of electrical equipment 102 to charge the cells 140 supplying power to the first type of electrical equipment 102, until the electricity levels of the cells 140 in each part of the battery pack 110, such as the four cells 140 in Figure 5, are balanced.

[0088] Referring to the power supply system shown in Figure 4, the four timing sequences for self-heating are as follows:

[0089] Timing 1: As shown in Figure 10, the upper bridge is closed, the lower bridge is open, and the first switch is closed. The upper half of the battery charges the inductor, which stores energy. Simultaneously, the voltage of the upper half of the battery drops. Assuming 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. Therefore, the voltage drop ΔU = I*R.

[0090] Timing 2: As shown in Figure 11, the upper bridge is open, the lower bridge is closed, and the first switch is closed. The inductor releases the stored energy to the lower half of the circuit, causing the voltage of the lower half to rise. At this time, the voltage rise of the lower half of the circuit is ΔU = I*R.

[0091] Timing 3: As shown in Figure 12, the upper bridge is open, the lower bridge is closed, and the first switch is closed. The lower half of the circuit charges the inductor, which stores energy. At the same time, the voltage of the lower half of the circuit drops. At this time, the voltage drop of the lower half of the circuit is ΔU = I*R.

[0092] Timing 4: As shown in Figure 13, the upper bridge is closed, the lower bridge is open, and the first switch is closed. The inductor releases the stored energy to the upper half of the circuit, causing the voltage of the upper half to rise. At this time, the voltage rise of the upper half of the circuit is ΔU = I*R.

[0093] Through timing sequences 1 to 4, current flows through the bridge arm and inductor, charging and discharging back and forth between the upper and lower battery packs, thus heating the battery. Simultaneously, the voltages of the upper and lower battery packs fluctuate due to the continuous charging and discharging of the current. Since the total bus voltage equals the sum of the upper and lower battery pack voltages, when the upper battery pack discharge voltage decreases, the lower battery pack charging voltage increases, thus keeping the total battery pack voltage constant. Therefore, the voltage of electrical equipment connected to the DC bus, such as type 2 electrical equipment 101, is not affected by the self-heating function. In this application, the voltage of electrical devices connected to the half-pack, such as the first type of electrical device 102, will not be affected. Since the first type of electrical device 102 is connected to the two half-packs and is jointly powered by the battery cells 140 of the two half-packs, the power supply of the first type of electrical device 102 = the voltage of the battery cells 140 in the upper half-pack + the voltage of the battery cells 140 in the lower half-pack. During the alternating charging and discharging states of the upper and lower half-packs, the battery cells 140 in the upper half-pack are charging while the battery cells 140 in the lower half-pack are discharging, and vice versa. The change in charge ΔU is equal, so the voltage changes of the upper and lower half-packs can be canceled out. Taking the above four self-heating sequence processes as a cycle, the voltage increase of the upper half-pack and the voltage decrease of the lower half-pack, as well as the voltage decrease of the upper half-pack and the voltage increase of the lower half-pack, cancel each other out in one cycle. Therefore, the total voltage supplied to the first type of electrical device 102 in one cycle remains unchanged.

[0094] Therefore, the power supply system 100 of this application can prevent large fluctuations in the power supply of the first type of electrical equipment 102 and ensure the normal operation of the first type of electrical equipment 102.

[0095] In some embodiments, the battery pack 110 includes 2W battery groups connected in series, each battery group including at least one cell 140, the midpoint of the 2W battery groups is the midpoint 113 of the cell groups, the W battery groups between the midpoint of the 2W battery groups and the first end of the battery pack are the first equalization connection terminal 111, and the W battery groups between the midpoint of the 2W battery groups and the second end of the battery pack are the second equalization connection terminal 112, where W is an even number.

[0096] Specifically, as shown in Figure 2, the battery pack 110 includes 2W battery groups connected in series. Each battery group includes at least one cell 140, where W is an even number, such as 2, 4, 6, etc. The corresponding battery groups are 4, 8, and 12. The number of battery groups between the midpoint 113 of the cell and the first end of the battery pack is equal to the number of battery groups between the midpoint 113 of the cell and the second end of the battery pack. In other words, the battery groups are divided equally according to the midpoint 113 of the cell.

[0097] For the battery cell 140 that supplies power to the first type of electrical equipment, preferably, the number of battery cells 140 in the two half-packs is the same. In actual application, the power supply system 100 has a certain resistance to voltage disturbances. The number of battery cells 140 in the two half-packs can satisfy the relationship mentioned above (Equation 2), that is, ensure that the voltage from the two balanced connection terminals to the midpoint 113 of the battery cell is approximately equal.

[0098] A second aspect of this disclosure provides a vehicle 200, as shown in FIG14. The vehicle 200 includes: a second type of electrical equipment 101, a first type of electrical equipment 102, a controller 201, and a power supply system 100.

[0099] The power supply system 100 can be connected to the second type of electrical equipment 101 and the first type of electrical equipment 102 respectively, and the controller 201 is connected to the power supply system 100 to realize the self-heating of the battery pack 110 and the power balance of each part of the battery pack 110.

[0100] According to the vehicle 200 of this disclosure, by adopting the power supply system 100 of the above embodiment, power is evenly drawn from the midpoint of the battery pack 110, and the electrical properties of the two half-packs are used to jointly power the first type of electrical equipment 102. When the battery pack 110 self-heats, sudden changes in the power supply to the first type of electrical equipment 102 can be avoided, thus ensuring the stability of the power supply.

[0101] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0102] Although embodiments of this disclosure have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. A power supply system (100), characterized by, The power supply system (100) comprises: a battery pack (110) comprising a plurality of battery cells (140) connected in series, a first equalization connection end (111) between a midpoint (113) of the plurality of battery cells and a first end of the battery pack (110) adapted to be connected to a first end of a first type of electrical device (102), and a second equalization connection end (112) between the midpoint (113) of the plurality of battery cells and a second end of the battery pack (110) adapted to be connected to a second end of the first type of electrical device (102).

2. The power supply system (100) according to claim 1, wherein: the first end of the battery pack (110) is adapted to be connected to a first end of a second type of electrical device (101), and the second end of the battery pack (110) is adapted to be connected to a second end of the second type of electrical device (101), wherein a voltage of the second type of electrical device (101) is greater than a voltage of the first type of electrical device (102).

3. The power supply system (100) according to claim 2, characterized in that The power supply system (100) further comprises: a battery management circuit module (120) having a first end connected to the first end of the battery pack (110), a second end connected to the second end of the battery pack (110), and a third end connected to the midpoint (113) of the plurality of battery cells (140) for heating the battery pack (110).

4. The power supply system (100) according to any one of claims 1-3, characterized in that, A number of battery cells (140) between the midpoint (113) of the plurality of battery cells and the first equalization connection end (111) is M, and a number of battery cells between the midpoint (113) of the plurality of battery cells and the second equalization connection end (112) is N, wherein the M and the N are equal or not equal.

5. The power supply system (100) according to claim 3, characterized in that A fourth end of the battery management circuit module (120) is connected to the first equalization connection end (111), and a fifth end of the battery management circuit module (120) is connected to the second equalization connection end (112) for balancing the electric quantity of the battery cells (140) in the battery pack (110).

6. The power supply system (100) according to claim 5, characterized in that The battery management circuit module (120) comprises: at least one inductor (103) having a first end connected to the midpoint (113) of the plurality of battery cells (140); at least one bridge arm circuit (130) corresponding to the at least one inductor (103), wherein a first end of each bridge arm circuit (130) is connected to the first end of the battery pack (110), a second end of each bridge arm circuit (130) is connected to the second end of the battery pack (110), and a midpoint of each bridge arm circuit (130) is connected to a second end of the corresponding inductor (103) for controlling the charging and discharging of the corresponding inductor (103) to achieve heating and balancing of the electric quantity of the battery pack (110).

7. The power supply system (100) according to claim 6, characterized in that Each of the bridge arm circuits (130) comprises a first switch tube (131) and a second switch tube (132), a first end of the first switch tube (131) is connected with the first end of the battery pack (110), a second end of the first switch tube (131) is connected with a first end of the second switch tube (132), a second end of the second switch tube (132) is connected with the second end of the battery pack (110), and a midpoint of the bridge arm circuit (130) is between the second end of the first switch tube (131) and the first end of the second switch tube (132).

8. The power supply system (100) according to claim 6 or 7, characterized in that The battery management circuit module (120) further comprises: a first switch (104), a first end of each of the inductors (103) is connected with the midpoint (113) of the plurality of the battery cells through the first switch (104), and the first switch (104) is used to control switching of a heating function of the battery management circuit module (120) on the battery pack (110).

9. The power supply system (100) according to any one of claims 6-8, characterized in that, The battery management circuit module (120) further comprises: a first diode unit (106) and a second diode unit (107), an output end of the first diode unit (106) is connected with the first equalization connection end (111), a first end of each of the inductors (103) is connected with an input end of the first diode unit (106), the input end of the first diode unit (106) is also connected with an output end of the second diode unit (107), and an input end of the second diode unit (107) is connected with the second equalization connection end (112) to realize equalization of electric quantity of the battery cells (140) in the battery pack (110).

10. The power supply system (100) according to claim 9, characterized in that The battery management circuit module (120) further comprises: a second switch (105), the input end of the first diode unit (106) and the output end of the second diode unit (107) are both connected with the first end of each of the inductors (103) through the second switch (105), and the second switch (105) is used to control switching of an equalization function of electric quantity of the battery cells (140) in the battery pack (110) by the battery management circuit module (120).

11. The power supply system (100) according to any one of claims 1-10, characterized in that, The battery pack (110) comprises 2W battery groups connected in series, each of the battery groups comprises at least one of the battery cells (140), a midpoint of 2W battery groups is the midpoint (113) of the plurality of the battery cells, W battery groups between the midpoint of 2W battery groups and the first end of the battery pack (110) are the first equalization connection end (111), W battery groups between the midpoint of 2W battery groups and the second end of the battery pack (110) are the second equalization connection end (112), and the W is an even number.

12. A vehicle (200), characterized in that The power supply system (100) comprises a first type of electrical equipment (102), a second type of electrical equipment (101), a controller (201), and the power supply system (100) according to any one of claims 1-11.

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