Battery pack charging device, its control method, and vehicle having the same

Abstract

The present invention discloses a battery pack charging device, a control method thereof, and a vehicle having the same, including: a battery pack, the battery pack including a first sub-battery pack and a second sub-battery pack connected in series; a DC charging interface, the positive pole of the DC charging interface being connected to the positive pole of the battery pack, and the negative pole of the DC charging interface being connected to the negative pole of the battery pack; a control unit, the control unit including a control module and a driving module, the driving module including at least one bridge arm, the bridge arm including an upper bridge arm and a lower bridge arm, the upper bridge arm being connected to the positive pole of the battery pack, and the lower bridge arm being connected to the negative pole of the battery pack; an inductor, one end of the inductor being connected to the midpoint of the first sub-battery pack and the second sub-battery pack and the positive pole of the DC charging interface, and the other end of the inductor being connected to the midpoint of the bridge arm. The battery pack charging device according to the embodiment of the present invention can control the self-heating of the battery pack, and has two charging circuits, can perform boost charging and direct charging on the battery pack, and also has the advantages of low cost, small space, and few components.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and more particularly to a battery pack charging device, a control method thereof, and a vehicle having the same. Background Art

[0002] When the battery pack in the related art is in a low-temperature state, it is usually heated by a PTC heating element, which requires adding additional electrical components, increasing the production cost and the volume. And when charging the battery pack, the voltage of a common battery cabinet is usually low, and rapid charging of the battery pack cannot be achieved. Even if there is a boost charging function in some battery pack charging devices, the boost charging circuit and the battery pack heating circuit are separately arranged, which also results in low space utilization and high cost. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. For this purpose, an object of the present invention is to provide a battery pack charging device, which can not only control the battery pack to self-heat, but also has two charging circuits for the battery pack, can perform boost charging and direct charging on the battery pack, ensure the charging efficiency of the battery pack, and also has the advantages of low cost, small space, and few components.

[0004] The present invention also provides a control method for the above battery pack charging device.

[0005] The present invention also provides a vehicle having the above battery pack charging device.

[0006] To achieve the above object, according to a first aspect embodiment of the present invention, a battery pack charging device is provided, including: a battery pack, the battery pack including a first sub-battery pack and a second sub-battery pack connected in series; a DC charging interface, the positive electrode of the DC charging interface being connected to the positive electrode of the battery pack, and the negative electrode of the DC charging interface being connected to the negative electrode of the battery pack; a control unit, the control unit including a control module and a driving module, the control module being configured to send a signal for controlling the driving module to execute, the driving module including at least one bridge arm, the bridge arm including an upper bridge arm and a lower bridge arm, the upper bridge arm being connected to the positive electrode of the battery pack, and the lower bridge arm being connected to the negative electrode of the battery pack; and an inductor, one end of the inductor being connected to the midpoint of the first sub-battery pack and the second sub-battery pack and the positive electrode of the DC charging interface, and the other end of the inductor being connected to the midpoint of the bridge arm.

[0007] The battery pack charging device according to the embodiment of the present invention can not only control the battery pack to achieve self-heating, but also has two charging circuits for the battery pack, can perform boost charging and direct charging on the battery pack, ensure the charging efficiency of the battery pack, and also has the advantages of low cost, small space, and few components.

[0008] According to some embodiments of the present invention, the inductor is at least one phase winding of the motor.

[0009] According to some embodiments of the present invention, the inductor is a three-phase winding of the motor; the control unit includes a motor controller, the motor controller includes the drive module, the drive module includes three bridge arms, and each of the three bridge arms includes an upper bridge arm and a lower bridge arm. The three upper bridge arms are connected together and then connected to the positive pole of the battery pack, and the three lower bridge arms are connected together and then connected to the negative pole of the battery pack; one ends of the three-phase windings are respectively connected to the midpoints of the three bridge arms, and the other ends of the three-phase windings are connected together and then connected to the midpoint of the first sub-battery pack and the second sub-battery pack and the positive pole of the DC charging interface through the N line.

[0010] According to some embodiments of the present invention, the battery pack charging device further includes: a capacitor, one end of the capacitor is connected to the positive pole of the battery pack, and the other end of the capacitor is connected to the negative pole of the battery pack.

[0011] According to some embodiments of the present invention, the capacitor includes a first capacitor and a second capacitor connected in series. Both the first capacitor and the second capacitor are X capacitors. One end of the first capacitor is connected to one end of the second capacitor, the other end of the first capacitor is connected to the negative pole of the battery pack, and the other end of the second capacitor is connected to the positive pole of the battery pack.

[0012] According to some embodiments of the present invention, the first capacitor is an X2 capacitor, and the second capacitor is an X1 capacitor.

[0013] According to some embodiments of the present invention, the capacitor further includes: a boost capacitor, one end of the boost capacitor is connected to the negative pole of the battery pack, and the other end of the boost capacitor is connected to the positive pole of the battery pack through the inductor.

[0014] According to some embodiments of the present invention, the battery pack charging device further includes: a resistor, and both ends of the resistor are respectively connected to the positive pole and the negative pole of the DC charging interface.

[0015] According to some embodiments of the present invention, the battery pack charging device further includes: an X-capacitor contactor, one end of the X-capacitor contactor is connected to the one end of the second capacitor, and the other end of the X-capacitor contactor is connected to the one end of the inductor through the N line.

[0016] According to some embodiments of the present invention, the battery pack charging device further includes: a contactor, and the contactor is connected between the positive pole of the DC charging interface and the positive pole of the battery pack.

[0017] According to some embodiments of the present invention, the battery pack charging device further includes: a positive fuse, one end of the positive fuse is connected to the positive electrode of the battery pack and the other end is connected to the upper bridge arm; and a negative fuse, one end of the negative fuse is connected to the negative electrode of the battery pack and the other end is connected to the lower bridge arm.

[0018] According to some embodiments of the present invention, the battery pack charging device further includes: an AC charging interface; an on-vehicle charger, an input end of the on-vehicle charger is connected to the AC charging interface; and a DC / DC module, an input end of the DC / DC module is connected to an output end of the on-vehicle charger, and an output end of the DC / DC module is connected to the battery pack.

[0019] According to some embodiments of the present invention, the battery pack charging device further includes: a first magnetic ring, the battery pack and the bridge arm are connected through a first conductive structure, and the first magnetic ring surrounds the first conductive structure; and a second magnetic ring, the DC charging interface is connected to the battery pack and the inductor through a second conductive structure, and the second magnetic ring surrounds at least one of the second conductive structure and the DC charging interface.

[0020] According to a second aspect embodiment of the present invention, a battery pack charging method is provided, which is applied to the battery pack charging device according to the first aspect embodiment of the present invention, and includes: when the charging device is connected to a charging device, obtaining temperature information of the battery pack and charging voltage information of the charging device; when the temperature of the battery pack is lower than a first preset temperature threshold, the control unit operates to alternately charge and discharge the first sub-battery pack and the second sub-battery pack to increase the temperature of the battery pack; when the charging voltage information is lower than a preset voltage threshold, the control unit operates to increase the charging voltage between the positive and negative electrodes of the battery pack.

[0021] According to the charging method of the second aspect embodiment of the present invention, by using the battery pack charging device according to the first aspect embodiment of the present invention, not only can the self-heating of the battery pack be realized, but also the battery pack has two charging circuits, which can perform boost charging and direct charging on the battery pack, ensuring the charging efficiency of the battery pack, and also having advantages such as low cost, small space, and few parts.

[0022] According to some embodiments of the present invention, when the temperature of the battery pack is lower than the first preset temperature threshold, the control unit operates to cause the first sub-battery pack and the second sub-battery pack to charge and discharge each other to increase the temperature of the battery pack, which includes: the control module controls the three upper bridge arms and the three lower bridge arms to be connected or turned off simultaneously, and the states of the three upper bridge arms and the three lower bridge arms are opposite, so that when the first sub-battery pack discharges, the second sub-battery pack charges or when the second sub-battery pack discharges, the first sub-battery pack charges.

[0023] According to some embodiments of the present invention, when the charging voltage is lower than the preset voltage threshold, the control unit operates to increase the charging voltage between the positive and negative electrodes of the battery pack, which includes: the control module controls the charging device to be connected to the positive electrode of the battery pack through the motor and the three-phase bridge arm, and by controlling the connection and disconnection of the three-phase bridge arm in the drive module, the voltage between the positive and negative electrodes of the battery pack is increased to the preset voltage threshold.

[0024] According to some embodiments of the present invention, the preset voltage threshold is set between 470V and 610V.

[0025] According to some embodiments of the present invention, the battery pack charging method further includes: when the temperature of the battery pack is higher than the second preset temperature threshold, the control unit operates to cause the first sub-battery pack and the second sub-battery pack to stop alternating charging and discharging.

[0026] According to some embodiments of the present invention, the first preset temperature threshold is 10°C; the second preset temperature threshold is 20°C.

[0027] According to an embodiment of the third aspect of the present invention, a vehicle is provided, which includes the battery pack charging device according to the embodiment of the first aspect of the present invention.

[0028] The vehicle according to the embodiment of the third aspect of the present invention, by using the battery pack charging device according to the embodiment of the first aspect of the present invention, can not only realize self-heating of the battery pack, but also has two charging circuits for the battery pack, can perform boost charging and direct charging on the battery pack, ensure the charging efficiency of the battery pack, and also has the advantages of low cost, small space, and few parts.

[0029] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which:

[0031] Figure 1 It is a schematic structural diagram of a battery pack charging device according to an embodiment of the present invention.

[0032] Figure 2 It is a flowchart of a control method for a battery pack charging device according to an embodiment of the present invention.

[0033] Reference numerals:

[0034] Battery pack charging device 1,

[0035] Battery pack 100, first sub-battery pack 110, second sub-battery pack 120, first magnetic ring 130, DC bus connector 140,

[0036] DC charging interface 200, AC charging interface 210, on-vehicle charger 220, DC / DC module 230, second magnetic ring 240,

[0037] Bridge arm 300, upper bridge arm 310, positive fuse 311, lower bridge arm 320, negative fuse 321, control module 331, drive module 332, dotted line 333,

[0038] Inductor 400, motor 500, N wire 510, heating contactor 520, resistor 530,

[0039] Capacitor 600, first capacitor 610, second capacitor 620, boost capacitor 630,

[0040] Resistor 700, X capacitor contactor 800, contactor 900. Detailed implementation manners

[0041] The embodiments of the present invention will be described in detail below. The embodiments described with reference to the drawings are exemplary. The embodiments of the present invention will be described in detail below.

[0042] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the connections described in this application include both direct connections and indirect connections.

[0043] In the description of the present invention, "a plurality of" means two or more.

[0044] The battery pack charging device 1 according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0045] As Figure 1 and Figure 2 shown, the battery pack charging device 1 according to an embodiment of the present invention includes a battery pack 100, a DC charging interface 200, a control unit 300, and an inductor 400.

[0046] The battery pack 100 includes a first sub - battery pack 110 and a second sub - battery pack 120 connected in series. The positive electrode of the DC charging interface 200 is connected to the positive electrode of the battery pack 100, and the negative electrode of the DC charging interface 200 is connected to the negative electrode of the battery pack 100. The control unit 300 includes a control module 331 and a driving module 332. The control module 331 is used to send a signal for controlling the driving module 332 to execute. The driving module 332 includes at least one bridge arm 300. The bridge arm 300 includes an upper bridge arm 310 and a lower bridge arm 320. The upper bridge arm 310 is connected to the positive electrode of the battery pack 100, and the lower bridge arm 320 is connected to the negative electrode of the battery pack 100. One end of the inductor 400 is connected to the mid - point between the first sub - battery pack 110 and the second sub - battery pack 120 and the positive electrode of the DC charging interface 200, and the other end of the inductor 400 is connected to the mid - point of the bridge arm 300.

[0047] It should be noted that one end of the inductor 400 is connected to the mid - point between the first sub - battery pack 110 and the second sub - battery pack 120, which means that one end of the inductor 400 is connected between the first sub - battery pack 110 and the second sub - battery pack 120, rather than being connected to the middle position between the first sub - battery pack 110 and the second sub - battery pack 120; each bridge arm 300 includes two power switches connected in series. The other end of the inductor 400 is connected to the mid - point of the bridge arm 300, which means that the other end of the inductor 400 is connected between the two power switches of the same bridge arm 300, rather than being connected to the middle position between the two power switches of the same bridge arm 300.

[0048] For example, a heating contactor 520 and a resistor 530 are connected between the inductor 400 and the battery pack 100. The heating contactor 520 is used to control the on - off between the above - mentioned one end of the inductor 400 and the battery pack 100, and the resistor 530 is used to improve the safety of the circuit.

[0049] In the battery pack charging device 1 according to an embodiment of the present invention, the battery pack 100 is divided into a first sub - battery pack 110 and a second sub - battery pack 120 connected in series. Among them, the capacitance values of the first sub - battery pack 110 and the second sub - battery pack 120 can be the same, and temperature sensors can be installed on the first sub - battery pack 110 and the second sub - battery pack 120 to detect the temperatures of the first sub - battery pack 110 and the second sub - battery pack 120.

[0050] In addition, the bridge arm 300 includes an upper bridge arm 310 and a lower bridge arm 320. The upper bridge arm 310 is connected to the positive electrode of the battery pack 100, and the lower bridge arm 320 is connected to the negative electrode of the battery pack 100. One end of the inductor 400 is connected to the midpoint of the first sub-battery pack 110 and the second sub-battery pack 120 and the positive electrode of the DC charging interface 200, and the other end of the inductor 400 is connected to the midpoint of the bridge arm 300.

[0051] For example, in the positive half-cycle of the fundamental wave period, when the upper bridge arm 310 is turned on and the lower bridge arm 320 is turned off, the first sub-battery pack 110 discharges, and a loop is formed through the IGBT of the upper bridge arm 310. The current of the first sub-battery pack 110 charges the inductor 400 through the upper bridge arm 310. When the lower bridge arm 320 is turned on and the upper bridge arm 310 is turned off, the inductor 400 continues to flow to charge the second sub-battery pack 120, and a loop is formed through the diode of the lower bridge arm 320; in the negative half-cycle of the fundamental wave period, when the lower bridge arm 320 is turned on and the upper bridge arm 310 is turned off, the second sub-battery pack 120 discharges to the inductor 400, and a loop is formed through the IGBT of the lower bridge arm 320. The current of the second sub-battery pack 120 charges the inductor 400 through the upper bridge arm 310. When the upper bridge arm 310 is turned on and the lower bridge arm 320 is turned off, the inductor 400 continues to flow to charge the first sub-battery pack 110, and a loop is formed through the diode of the upper bridge arm 310.

[0052] By controlling the upper bridge arm 310 and the lower bridge arm 320 to operate at a high-frequency switching frequency, the first sub-battery pack 110 and the second sub-battery pack 120 charge and discharge each other through current oscillation, causing the internal resistance of the first sub-battery pack 110 and the internal resistance of the second sub-battery pack 120 to generate heat, thereby realizing self-heating of the battery pack 100. Among them, the current amount between the inductor 400 and the battery pack 100 can be monitored by a Hall sensor.

[0053] In this way, in a low-temperature environment, the battery pack 100 can perform self-heating, which can not only improve the power supply efficiency of the battery pack 100. For example, when the vehicle is driving, the battery pack 100 can perform self-heating to keep the battery pack 100 in a working state of high-efficiency power supply. Moreover, when the battery pack 100 is charging, the battery pack 100 can perform self-heating first, thereby improving the charging efficiency. The battery pack charging device 1 does not need to be additionally provided with a PTC heating element, reducing the cost, reducing the volume, and reducing the number of parts.

[0054] In addition, the positive electrode of the DC charging interface 200 is connected to the positive electrode of the battery pack 100, and the negative electrode of the DC charging interface 200 is connected to the negative electrode of the battery pack 100. When the DC charging interface 200 is connected to a high-voltage dedicated DC charging cabinet with a charging voltage of 750V, the DC charging interface 200 can directly charge the battery pack 100.

[0055] Moreover, one end of the inductor 400 is connected to the positive electrode of the DC charging interface 200. When the DC charging interface 200 is connected to an ordinary charging cabinet with a charging voltage less than 750V (for example, the charging voltage is 470V), after the current at the positive electrode of the DC charging interface 200 flows to the inductor 400, first, the upper bridge arm 310 is turned off and the lower bridge arm 320 is turned on. At this time, the voltage of the current on the inductor 400 continues to rise. Then, the upper bridge arm 310 is turned on and the lower bridge arm 320 is turned off. At this time, the current on the inductor 400 charges the battery pack 100. Next, the upper bridge arm 310 is turned off again and the lower bridge arm 320 is turned on again. At this time, the voltage of the current on the inductor 400 continues to rise. The upper bridge arm 310 is turned on again and the lower bridge arm 320 is turned off again. At this time, the current on the inductor 400 charges the battery pack 100. By continuously cycling the above process, the charging voltage of the battery pack 100 can rise above 630V, and the voltage across the two ends of the battery pack 100 is greater than the voltage across the two ends of the DC charging interface 200. Thus, the battery pack charging device 1 can increase the charging voltage of the battery pack 100 and improve the charging speed of the battery pack 100.

[0056] The boost charging circuit and the self-heating circuit of the battery pack 100 share the inductor 400 and the bridge arm 300 of the control unit, reducing the number of components, lowering the cost, and decreasing the volume.

[0057] In this way, the battery pack charging device 1 according to the embodiment of the present invention can not only control the battery pack 100 to achieve self-heating, but also has two charging circuits for the battery pack 100, can perform boost charging and direct charging on the battery pack 1, ensure the charging efficiency of the battery pack 100, and also has the advantages of low cost, small space, and few components.

[0058] According to some specific embodiments of the present invention, as Figure 1 shown, the inductor 400 is at least one-phase winding of the motor 500. The winding of the motor 500 is reused in the self-heating circuit and the boost charging circuit of the battery pack 1. Without the need to additionally set an inductor component, the utilization rate of the winding of the motor 500 can be improved, the number of components of the battery pack charging device 1 can be reduced, and the volume of the battery pack charging device 1 is smaller.

[0059] According to some specific embodiments of the present invention, as Figure 1As shown, the inductor 400 is a three-phase winding of the motor 500. The control unit includes a motor controller, and the motor controller includes a driving module 332. The driving module 332 includes three bridge arms 300. Each of the three bridge arms 300 includes an upper bridge arm 310 and a lower bridge arm 320. After the three upper bridge arms 310 are connected together, they are connected to the positive pole of the battery pack 100. After the three lower bridge arms 320 are connected together, they are connected to the negative pole of the battery pack 100. One ends of the three-phase windings are respectively connected to the midpoints of the three bridge arms 300, and the other ends of the three-phase windings are connected together and then connected to the midpoint of the first sub-battery pack 110 and the second sub-battery pack 120 and the positive pole of the DC charging interface 200 through the N line 510.

[0060] That is to say, the motor 500 is a three-phase motor 500. The motor 500 can be a driving motor or a generator. By applying the three-phase winding to the battery pack charging device 1 and connecting the three-phase winding to the three bridge arms 300 of the control unit in a one-to-one correspondence, the probability of generating ripple current in the circuit of the battery pack charging device 1 can be reduced, the stability of the charging voltage of the battery pack 100 is ensured, and the power quality can be improved.

[0061] According to some specific embodiments of the present invention, as Figure 1 shown, the battery pack charging device 1 further includes a capacitor 600. One end of the capacitor 600 is connected to the positive pole of the battery pack 100, and the other end of the capacitor 600 is connected to the negative pole of the battery pack 100.

[0062] Wherein, when the battery pack 100 supplies power to the bridge arm 300 of the control unit, the current of the battery pack 100 will first pass through the capacitor 600 to absorb the ripple current flowing out of the battery pack 100 and filter the output current of the battery pack 100 to ensure the stability of the voltage supplied to the bridge arm 300 of the control unit; when charging the battery pack 100, the current input to the battery pack 100 will first pass through the capacitor 600, and the capacitor 600 can absorb the ripple current in the current input to the battery pack 100 to make the charging voltage of the current flowing into the battery pack 100 stable.

[0063] According to some specific embodiments of the present invention, as Figure 1 shown, the capacitor 600 includes a first capacitor 610 and a second capacitor 620 connected in series. Both the first capacitor 610 and the second capacitor 620 are X capacitors. One end of the first capacitor 610 is connected to one end of the second capacitor 620, the other end of the first capacitor 610 is connected to the negative pole of the battery pack 100, and the other end of the second capacitor 620 is connected to the positive pole of the battery pack 100.

[0064] By connecting the series-connected first capacitor 610 and second capacitor 620 to the positive and negative electrodes of the battery pack 100 respectively, the first capacitor 610 and the second capacitor 620 can jointly absorb the ripple current to achieve the purpose of stabilizing the output voltage of the battery pack 100 and the charging voltage input to the battery pack 100. Moreover, the X capacitor can be used to eliminate differential-mode interference.

[0065] According to some specific embodiments of the present invention, as Figure 1 shown, the first capacitor 610 is an X2 capacitor, and the second capacitor 620 is an X1 capacitor. Among them, the high-voltage withstand of the first capacitor 610 is not greater than 2.5 KV, and the high-voltage withstand of the second capacitor 620 is 2.5 KV - 4 KV.

[0066] The first capacitor 610 is used to absorb the differential-mode current on the N line 510 between the inductor 400 and the battery pack 100 when the battery pack 100 self-heats. As Figure 1 can be seen, the first capacitor 610 is connected to the N line 510 through the X-capacitor contactor 800. When the battery pack 100 self-heats, the N line 510 is turned on. The power of the battery pack 100 self-heating is not as large as the power when the IGBT converts current for vehicle driving. Therefore, the high-voltage withstand range of the first capacitor 610 can be smaller than that of the second capacitor 620.

[0067] The second capacitor 620 is a capacitor with a voltage stabilizing and filtering function when the battery pack 100 supplies power to the IGBT of the bridge arm 300 of the control unit. And the power when the IGBT converts current for vehicle driving is relatively large. Therefore, the high-voltage withstand range of the second capacitor 620 needs to be higher.

[0068] According to some specific embodiments of the present invention, as Figure 1 shown, the capacitor 600 further includes a boost capacitor 630. One end of the boost capacitor 630 is connected to the negative electrode of the battery pack 100, and the other end of the boost capacitor 630 is connected to the positive electrode of the battery pack 100 through the inductor 400. That is to say, the two ends of the boost capacitor 630 are respectively connected to the positive and negative electrodes of the DC charging interface 200.

[0069] Among them, the first capacitor 610, the second capacitor 620 and the three-phase winding form an L / C circuit. By setting the boost capacitor 630, the ripple current of the DC charging interface 200 can be absorbed, and the input current of the DC charging interface 200 can be filtered to stabilize the input voltage of the DC charging interface 200.

[0070] According to some specific embodiments of the present invention, as Figure 1 shown, the battery pack charging device 1 further includes a resistor 700. The two ends of the resistor 700 are respectively connected to the positive and negative electrodes of the DC charging interface 200. In this way, the short circuit between the positive and negative electrodes of the DC charging interface 200 can be prevented, and the safety of the battery pack charging device 1 can be improved.

[0071] According to some specific embodiments of the present invention, as Figure 1 shown, the battery pack charging device 1 further includes an X-capacitor contactor 800. One end of the X-capacitor contactor 800 is connected to one end of the second capacitor 620, and the other end of the X-capacitor contactor 800 is connected to one end of the inductor 400 and the midpoint of the first sub-battery pack 110 and the second sub-battery pack 120 through the N-line 510.

[0072] Through the setting of the X-capacitor contactor 800, it is possible to control whether the second capacitor 620 is connected to the N-line 510. When the battery pack charging device 1 boosts and charges the battery pack 100, the X-capacitor contactor 800 can be turned on so that the second capacitor 620 is connected to the N-line 510. Thus, the second capacitor 620 can play a role in absorbing the differential mode current on the N-line 510, so as to reduce the high-frequency differential mode current component between the positive and negative poles of the battery pack 100 and minimize the risk of high-frequency current saturation of the magnetic ring at a certain frequency point.

[0073] According to some specific embodiments of the present invention, as Figure 1 shown, the battery pack charging device 1 further includes a contactor 900, and the contactor 900 is connected between the positive pole of the DC charging interface 200 and the positive pole of the battery pack 100.

[0074] When the DC charging plug is connected to a high-voltage dedicated DC charging cabinet with a charging voltage of 750V, the contactor 900 can be turned on. At this time, the DC charging plug is directly connected to the battery pack 100, and the voltage of the DC charging plug can directly charge the battery pack 100 without boosting; when the DC charging plug is connected to an ordinary charging cabinet with a charging voltage less than 750V (for example, at 470V), the contactor 900 can be turned off. At this time, the DC charging plug is connected to the battery pack 100 through the inductor 400 and the bridge arm 300, and the voltage of the DC charging plug is boosted before charging the battery pack 100.

[0075] By setting the contactor 900, it is possible to control the selection of the charging circuit for the battery pack 100 and improve the flexibility of charging the battery pack 100.

[0076] According to some specific embodiments of the present invention, as Figure 1 shown, the battery pack charging device 1 further includes a positive pole fuse 311 and a negative pole fuse 321.

[0077] One end of the positive pole fuse 311 is connected to the positive pole of the battery pack 100 and the other end is connected to the upper bridge arm 310. By setting the positive pole fuse 311, it is possible to prevent part of the backflow current during the self-heating process of the battery pack 100 and the current on the positive pole of the battery pack 100 from being short-circuited, thereby improving the electrical connection safety of the battery pack charging device 1.

[0078] One end of the negative electrode fuse 321 is connected to the negative electrode of the battery pack 100, and the other end is connected to the lower bridge arm 320. By providing the negative electrode fuse 321, it is possible to prevent the driving current of the battery pack 100 on the bridge arm 300 from being too large, thus serving as a driving fuse.

[0079] According to some specific embodiments of the present invention, as Figure 1 shown, the battery pack charging device 1 further includes an AC charging interface 210, an on-board charger 220 (OBC), and a DC / DC module 230. The input end of the on-board charger 220 is connected to the AC charging interface 210, the input end of the DC / DC module 230 is connected to the output end of the on-board charger 220, and the output end of the DC / DC module 230 is connected to the battery pack 100.

[0080] Among them, the on-board charger 220 has the function of converting AC to DC. The function of the DC / DC module 230 is to convert the high-voltage direct current of the on-board charger 220 into low-voltage direct current. The AC charging interface 210 can be connected to a high-voltage AC power source. After converting the alternating current of the AC charging interface 210 into direct current by the on-board charger 220, it supplies power to the battery pack 100 through the DC / DC module 230.

[0081] According to some specific embodiments of the present invention, as Figure 1 shown, the battery pack charging device 1 further includes a first magnetic ring 130 and a second magnetic ring 240. The battery pack 100 is connected to the bridge arm 300 through a first conductive structure. The first magnetic ring 130 surrounds the first conductive structure. The DC charging interface 200 is connected to the battery pack 100 and the inductor 400 through a second conductive structure. The second magnetic ring 240 surrounds at least one of the second conductive structure and the DC charging interface 200.

[0082] The first magnetic ring 130 and the second magnetic ring 240 have a good inhibitory effect on high-frequency noise and play an anti-interference role, thereby reducing the fluctuation of the DC voltage input from the DC charging interface 200 to the battery pack charging device 1, and can also reduce the fluctuation of the DC voltage input from the battery pack charging device 1 to the battery pack 100. In this way, the fluctuation amplitude and frequency of the charging voltage of the battery pack 100 will be greatly reduced, and the charging voltage of the battery pack 100 will be more stable. This can not only improve the charging safety of the battery pack 100, but also avoid the loss of the battery pack 100 caused by the fluctuation of the charging voltage, and prolong the service life of the battery pack 100.

[0083] Next, a battery pack charging method according to the above embodiments of the present invention will be described with reference to the accompanying drawings, which is applied to the battery pack charging device 1 as in the above embodiments of the present invention.

[0084] As Figure 2As shown, the control method of the battery pack charging device 1 of the above embodiment includes:

[0085] When the charging device 1 is connected to the charging equipment, obtain the temperature information of the battery pack 100 and the charging voltage information of the charging equipment;

[0086] When the temperature of the battery pack 100 is lower than the first preset temperature threshold, the control unit operates to make the first sub-battery pack 110 and the second sub-battery pack 120 alternately charge and discharge to increase the temperature of the battery pack 100;

[0087] When the charging voltage information is lower than the preset voltage threshold, the control unit operates to increase the charging voltage between the positive and negative electrodes of the battery pack 100.

[0088] Among them, the acquisition of the temperature information can be achieved by setting a temperature sensor in the battery pack 100. The temperature sensor obtains the temperature information and transmits the temperature information to the control module 331. The control module 331 compares the received temperature information with the first preset temperature and sends the next instruction according to the comparison result.

[0089] The charging voltage information of the charging equipment is collected by a high-voltage acquisition signal line. For example, Figure 1 the dotted line 333 connected from the DC charging interface in the attachment. The high-voltage acquisition signal line sends the collected charging voltage information to the control module 331. The control module 331 compares the charging voltage information with the preset voltage threshold and sends the next instruction according to the comparison result.

[0090] When the temperature of the battery pack 100 is lower than the first preset temperature threshold, the working efficiency of the battery pack 100 may be relatively low. At this time, it is necessary to heat the battery pack 100 so that the temperature of the battery pack 100 can be in a temperature range for efficient operation. Moreover, when the charging voltage is lower than the preset voltage threshold, boost the current flowing into the battery pack 100 to improve the working efficiency of the battery pack 100. When the charging voltage is not lower than the preset voltage, the charging current can directly flow into the battery pack 100 to charge the battery pack.

[0091] The voltage between the positive and negative electrodes of the battery pack 100 refers to the voltage between the positive and negative electrodes of the DC bus connector 140.

[0092] According to the control method of the embodiment of the present invention, by using the battery pack charging device 1 according to the above embodiment of the present invention, not only can the self-heating of the battery pack 100 be realized, but also there are two charging circuits for the battery pack 100, which can perform boost charging and direct charging on the battery pack 100, ensuring the charging efficiency of the battery pack, and also having the advantages of low cost, small space, and few components.

[0093] According to some specific embodiments of the present invention, such as Figure 2 As shown, when the temperature of the battery pack 100 is lower than the first preset temperature threshold, the control unit operates to cause the first sub-battery pack 110 and the second sub-battery pack 120 to charge and discharge each other to increase the temperature of the battery pack 100, including:

[0094] The control module 331 controls the three upper bridge arms 310 and the three lower bridge arms 320 to be connected or turned off simultaneously, and the states of the three upper bridge arms 310 and the three lower bridge arms 320 are opposite, so that when the first sub-battery pack 110 discharges, the second sub-battery pack 120 charges or when the second sub-battery pack 120 discharges, the first sub-battery pack 110 charges.

[0095] The ripple current in the battery pack 100 heating circuit and the boost circuit is less, which is beneficial to improving the voltage stability of the circuit.

[0096] According to some specific embodiments of the present invention, such as Figure 2 As shown, when the charging voltage is lower than the preset voltage threshold, the control unit operates to increase the charging voltage between the positive and negative electrodes of the battery pack 100, including:

[0097] The control module 331 controls the charging device to be connected to the positive electrode of the battery pack 100 after passing through the motor 500 and the three-phase bridge arm 300. By controlling the connection and disconnection sequence of the three-phase bridge arm 300 in the drive module 332, the voltage between the positive and negative electrodes of the battery pack 100 is increased to the preset voltage threshold.

[0098] In this way, the motor 500 and the three-phase bridge arm 300 are reused, and there is no need to additionally set inductive elements, which can improve the utilization rate of the windings of the motor 500, reduce the number of parts of the battery pack charging device 1, and make the volume of the battery pack charging device 1 smaller.

[0099] According to some specific embodiments of the present invention, such as Figure 2 As shown, the preset voltage threshold can be set between 470V and 610V. For example, the preset voltage threshold can be set to 470V, 600V or 610V, etc.

[0100] For example, there are currently 2 types of voltage specifications for charging piles on the market: one is between 470V and 600V, and the other is 750V. Generally, a voltage above 610V can be used to quickly charge the battery pack 100. That is to say, a boost charge is required when charging with a 470V - 600V charging pile.

[0101] According to some specific embodiments of the present invention, such as Figure 2 As shown, the battery pack charging method further includes:

[0102] When the temperature of the battery pack 100 is higher than the second preset temperature threshold, the control unit operates to stop the alternating charge and discharge of the first sub-battery pack 110 and the second sub-battery pack 120.

[0103] When the temperature of the battery pack 100 reaches the second preset temperature threshold, the working efficiency (power generation efficiency and charging efficiency) of the battery pack 100 is in a relatively high state. At this time, the self-heating mode can be stopped to prevent the temperature of the battery pack 100 from being too high and reduce the power consumption of the battery pack 100.

[0104] According to some specific embodiments of the present invention, the first preset temperature threshold is 10 °C, and the second preset temperature threshold is 20 °C. Generally, when the temperature is 10 °C, the working efficiency of the battery pack 100 is relatively low. When the temperature is around 20 °C, the battery pack 100 is in a normal temperature state and the working efficiency of the battery pack 100 is relatively high.

[0105] The vehicle according to an embodiment of the present invention will be described below with reference to the drawings. The vehicle includes the battery pack charging device 1 proposed in the above embodiment of the present invention.

[0106] The vehicle according to an embodiment of the present invention, by using the battery pack charging device 1 according to the above embodiment of the present invention, can not only realize the self-heating of the battery pack 100, but also has two charging circuits for the battery pack 100, and can perform boost charging and direct charging on the battery pack 100 to ensure the charging efficiency of the battery pack 100.

[0107] The other configurations and operations of the battery pack charging device 1, its control method, and the vehicle having the same according to the embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail here.

[0108] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0109] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery pack charging device, characterized in that, Comprising: A battery pack, the battery pack including a first sub-battery pack and a second sub-battery pack connected in series; A DC charging interface, the positive pole of the DC charging interface being connected to the positive pole of the battery pack, and the negative pole of the DC charging interface being connected to the negative pole of the battery pack; A control unit, the control unit including a control module and a drive module, the control module being used for sending signals to control the execution of the drive module, the drive module including at least one bridge arm, the bridge arm including an upper bridge arm and a lower bridge arm, the upper bridge arm being connected to the positive pole of the battery pack, and the lower bridge arm being connected to the negative pole of the battery pack; and An inductor, one end of the inductor being connected to the midpoint of the first sub-battery pack and the second sub-battery pack and the positive pole of the DC charging interface, and the other end of the inductor being connected to the midpoint of the bridge arm to control self-heating of the battery pack or increase the charging voltage of the battery pack.

2. The battery pack charging device according to claim 1, characterized in that The inductor is at least one phase winding of a motor.

3. The battery pack charging device according to claim 1, wherein The inductor is a three-phase winding of a motor; The control unit includes a motor controller, the motor controller including the drive module, the drive module including three bridge arms, the three bridge arms respectively including the upper bridge arm and the lower bridge arm, the three upper bridge arms being connected to the positive pole of the battery pack after being converged, and the three lower bridge arms being connected to the negative pole of the battery pack after being converged; One ends of the three-phase windings are respectively connected to the midpoints of the three bridge arms, and the other ends of the three-phase windings are connected to the midpoint of the first sub-battery pack and the second sub-battery pack and the positive pole of the DC charging interface through an N line after being converged.

4. The battery pack charging device according to claim 1, characterized in that, Further comprising: A capacitor, one end of the capacitor being connected to the positive pole of the battery pack, and the other end of the capacitor being connected to the negative pole of the battery pack.

5. The battery pack charging device according to claim 4, wherein, The capacitor includes a first capacitor and a second capacitor connected in series, both the first capacitor and the second capacitor being X capacitors, one end of the first capacitor being connected to one end of the second capacitor, the other end of the first capacitor being connected to the negative pole of the battery pack, and the other end of the second capacitor being connected to the positive pole of the battery pack.

6. The battery pack charging device according to claim 5, characterized in that, The first capacitor is an X2 capacitor, and the second capacitor is an X1 capacitor.

7. The battery pack charging device according to claim 4, wherein, The capacitor further includes: A boost capacitor, one end of the boost capacitor being connected to the negative pole of the battery pack, and the other end of the boost capacitor being connected to the positive pole of the battery pack through the inductor.

8. The battery pack charging device according to claim 1, characterized in that, Further comprising: A resistor, both ends of the resistor being respectively connected to the positive pole and the negative pole of the DC charging interface.

9. The battery pack charging device according to claim 5, wherein Further comprising: An X-capacitor contactor, one end of the X-capacitor contactor being connected to the one end of the second capacitor, and the other end of the X-capacitor contactor being connected to the one end of the inductor through an N line.

10. The battery pack charging device according to claim 1, characterized in that, Further comprising: A contactor, the contactor being connected between the positive pole of the DC charging interface and the positive pole of the battery pack.

11. The battery pack charging device according to claim 1, characterized in that, Further comprising: A positive pole fuse, one end of the positive pole fuse being connected to the positive pole of the battery pack and the other end being connected to the upper bridge arm; And A negative pole fuse, one end of the negative pole fuse being connected to the negative pole of the battery pack and the other end being connected to the lower bridge arm.

12. The battery pack charging device according to claim 1, characterized in that, Further comprising: An AC charging interface; An on-vehicle charger, the input end of the on-vehicle charger being connected to the AC charging interface; And A DC / DC module, the input end of the DC / DC module is connected to the output end of the on-vehicle charger, and the output end of the DC / DC module is connected to the battery pack.

13. The battery pack charging device according to claim 1, characterized in that, It further includes: A first magnetic ring, the battery pack is connected to the bridge arm through a first conductive structure, and the first magnetic ring surrounds the first conductive structure; And A second magnetic ring, the DC charging interface is connected to the battery pack and the inductor through a second conductive structure, and the second magnetic ring surrounds at least one of the second conductive structure and the DC charging interface.

14. A battery pack charging method, characterized in that, Applied to the battery pack charging device according to any one of claims 1-13, including: When the charging device is connected to the charging equipment, obtaining the temperature information of the battery pack and the charging voltage information of the charging equipment; When the temperature of the battery pack is lower than the first preset temperature threshold, the control unit works to make the first sub-battery pack and the second sub-battery pack charge and discharge alternately to increase the temperature of the battery pack; When the charging voltage information is lower than the preset voltage threshold, the control unit works to increase the charging voltage between the positive and negative poles of the battery pack.

15. The battery pack charging method according to claim 14, wherein, The statement that when the temperature of the battery pack is lower than the first preset temperature threshold, the control unit works to make the first sub-battery pack and the second sub-battery pack charge and discharge with each other to increase the temperature of the battery pack includes: The drive module includes three bridge arms, and each of the three bridge arms includes an upper bridge arm and a lower bridge arm. The control module controls the three upper bridge arms and the three lower bridge arms to be connected or turned off simultaneously, and the states of the three upper bridge arms and the three lower bridge arms are opposite, so that when the first sub-battery pack discharges, the second sub-battery pack charges or when the second sub-battery pack discharges, the first sub-battery pack charges.

16. The battery pack charging method according to claim 14, wherein The statement that when the charging voltage information is lower than the preset voltage threshold, the control unit works to increase the charging voltage between the positive and negative poles of the battery pack includes: The control module controls the charging equipment to be connected to the positive pole of the battery pack through the motor and the three-phase bridge arm. By controlling the connection and disconnection of the three-phase bridge arm in the drive module, the voltage between the positive and negative poles of the battery pack is increased to the preset voltage threshold.

17. The battery pack charging method according to claim 14, wherein The preset voltage threshold is set between 470V and 610V.

18. The battery pack charging method according to claim 14, wherein It further includes: When the temperature of the battery pack is higher than the second preset temperature threshold, the control unit works to make the first sub-battery pack and the second sub-battery pack stop charging and discharging alternately.

19. The battery pack charging method according to claim 18, wherein The first preset temperature threshold is 10°C; The second preset temperature threshold is 20°C.

20. A vehicle, characterized in that, Including the battery pack charging device according to any one of claims 1-13.

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