Battery heating charging system and vehicle

Abstract

The utility model discloses a battery heating charging system and vehicle relates to vehicle technical field. System includes: direct current charging mouth, power battery module, first motor drive module and second motor drive module, and power battery module includes switch subassembly and battery pack, switch subassembly is connected with direct current charging mouth, two motor drive module and battery pack respectively, and switch subassembly is configured as: in the first working condition, control first motor drive module and battery pack form self -heating loop, and battery pack is heated by first motor drive module, in the second working condition, control direct current charging mouth, second motor drive module and battery pack form boost charging loop, and the voltage of direct current charging mouth input is charged for battery pack after the voltage of direct current charging mouth input is boosted by first motor drive module. Therefore, through switch subassembly switches among different working conditions, can realize the decoupling and cooperation of battery self -heating and boost charging, and switch subassembly is integrated in power battery module, can simplify high voltage loop layout.

Description

Technical Field

[0001] This utility model relates to the field of vehicle technology, and in particular to a battery heating and charging system and a vehicle. Background Technology

[0002] With the increasing popularity of new energy vehicles, users have placed higher demands on charging efficiency and range performance in low-temperature environments. Currently, the increased internal resistance and reduced electrochemical reaction rate of power batteries in low-temperature environments lead to a decrease in usable battery capacity and a longer charging time, which has become a key technical challenge restricting the winter user experience of electric vehicles.

[0003] To improve the performance of low-temperature batteries, the relevant technologies mainly adopt the following two approaches: One approach is to heat the battery pack using external heating devices (such as heating films, PTC heaters, etc.), but this method suffers from problems such as uneven heating, high energy loss, and high system costs.

[0004] Secondly, the inductance of the motor windings in the vehicle's high-voltage circuit is reused to generate an oscillating current through high-frequency control, using the Joule heat generated by the winding resistance to self-heat the battery. However, in this solution, the heating and charging functions are usually time-sharingly multiplexed by the same motor, and the two functions are mutually constrained in terms of time. When the battery needs to be heated and charged at the same time, it cannot be done simultaneously, resulting in limited charging efficiency and longer waiting time for users to charge in low temperatures. Furthermore, the self-heating circuit topology is mostly based on the modification of the vehicle's existing high-voltage architecture, with switching components distributed in the high-voltage circuit, resulting in low system integration. This not only occupies more layout space but also increases wiring harness connection costs and the risk of failure. Utility Model Content

[0005] One objective of this invention is to propose a battery heating and charging system and vehicle that decouples and coordinates battery self-heating and boost charging, and simplifies the layout of the high-voltage circuit.

[0006] In a first aspect, this utility model proposes a battery heating and charging system, comprising: a DC charging port, a power battery module, a first motor drive module, and a second motor drive module. The power battery module includes a switch assembly and a battery pack. The switch assembly is connected to the DC charging port, the first motor drive module, the second motor drive module, and the battery pack, respectively. The switch assembly has at least a first operating state and a second operating state. In the first operating state, the switch assembly controls the first motor drive module and the battery pack to form a self-heating circuit, and the battery pack is self-heated by the first motor drive module. In the second operating state, the switch assembly controls the DC charging port, the second motor drive module, and the battery pack to form a boost charging circuit, and the voltage input from the DC charging port is boosted by the second motor drive module to charge the battery pack.

[0007] In some examples, the switching assembly also has a third operating state; wherein, in the third operating state, the switching assembly controls the DC charging port to form a direct charging circuit with the battery pack, and the voltage input to the DC charging port directly charges the battery pack.

[0008] In some examples, the battery pack includes a first battery half-pack and a second battery half-pack, the first motor drive module includes a first inverter and a first motor; the switching assembly includes a first switch K, a second switch K, and a third switch K, the first end of the first switch K is connected to the positive terminal of the first battery half-pack, the second end of the first switch K is connected to the positive DC side of the first inverter, the first end of the second switch K is connected to the negative terminal of the second battery half-pack, the second end of the second switch K is connected to the negative DC side of the first inverter, the first end of the third switch K is connected to the negative terminal of the first battery half-pack and the positive terminal of the second battery half-pack, and the second end of the third switch K is connected to the connection node between any winding of the first motor and the midpoint of the corresponding inverter bridge arm.

[0009] In some examples, the second motor drive module includes a second inverter and a second motor; the switching assembly further includes a fourth switch K, a fifth switch K, and a sixth switch K. The first end of the fourth switch K is connected to the second end of the first switch K and the positive DC side of the second inverter, respectively. The second end of the fourth switch K is connected to the positive terminal of the DC charging port. The first end of the fifth switch K is connected to the second end of the second switch K and the negative DC side of the second inverter, respectively. The second end of the fifth switch K is connected to the negative terminal of the DC charging port. The first end of the sixth switch K is connected to the positive terminal of the DC charging port. The second end of the sixth switch K is connected to the connection node between any winding of the second motor and the midpoint of the corresponding inverter bridge arm.

[0010] In some examples, the power battery module further includes a pre-charge resistor R and a first pre-charge switch K, wherein the pre-charge resistor R and the first pre-charge switch K are connected in series and then in parallel with the first switch K.

[0011] In some examples, the second motor drive module further includes a first pre-charge capacitor C, a second pre-charge switch K, and a third pre-charge switch K. The first pre-charge capacitor C and the second pre-charge switch K are connected in series between the second terminal of the sixth switch K and the negative DC terminal of the second inverter. The first terminal of the third pre-charge switch K is connected to the second terminal of the sixth switch K. The second terminal of the third pre-charge switch K is connected to the connection node between any winding of the second motor and the midpoint of the corresponding inverter bridge arm.

[0012] In some examples, the power battery module further includes a first fuse F and a second fuse F; the first fuse F is connected between the positive terminal of the first battery half-pack and the first terminal of the first switch K, and the second fuse F is connected between the negative terminal of the second battery half-pack and the first terminal of the second switch K.

[0013] In some examples, the first motor drive module further includes a third fuse F connected between the positive DC terminal of the first inverter and the second terminal of the first switch K; the second motor drive module further includes a fourth fuse F connected between the positive DC terminal of the second inverter and the second terminal of the first switch K.

[0014] In some examples, the first motor drive module is a front-wheel drive module of the vehicle, and the second motor drive module is a rear-wheel drive module of the vehicle; or, the first motor drive module is the rear-wheel drive module, and the second motor drive module is the front-wheel drive module.

[0015] Secondly, this utility model proposes a vehicle, including: the battery heating and charging system described in the first aspect.

[0016] This utility model discloses a battery heating and charging system and a vehicle. The battery heating and charging system includes: a DC charging port, a power battery module, a first motor drive module, and a second motor drive module. The power battery module includes a switch assembly and a battery pack. The switch assembly is connected to the DC charging port, the first motor drive module, the second motor drive module, and the battery pack, and has at least a first operating state and a second operating state. In the first operating state, the switch assembly controls the first motor drive module and the battery pack to form a self-heating circuit, and the battery pack is self-heated by the first motor drive module. In the second operating state, the switch assembly controls the DC charging port, the second motor drive module, and the battery pack to form a boost charging circuit, and the voltage input from the DC charging port is boosted by the first motor drive module to charge the battery pack. Therefore, by integrating the switch assembly inside the power battery module and using the switch assembly to switch between different operating states, battery self-heating and boost charging are independently executed by different motor drive modules, avoiding time conflicts caused by time-sharing multiplexing of the same motor and shortening the low-temperature charging waiting time. Simultaneously, the integrated switch assembly simplifies the high-voltage circuit layout and reduces system cost and failure risk.

[0017] Additional aspects and advantages of this invention 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 the invention. Attached Figure Description

[0018] Figure 1 This is a structural block diagram of the battery heating and charging system according to an embodiment of the present invention; Figure 2 This is a topology diagram of the battery heating and charging system according to the first embodiment of this utility model; Figure 3 This is a topology diagram of the battery heating and charging system according to the second embodiment of this utility model; Figure 4 This is a topology diagram of the battery heating and charging system according to the third embodiment of this utility model; Figure 5 This is a topology diagram of the battery heating and charging system according to the fourth embodiment of this utility model; Figure 6 This is a schematic diagram of the current path during the energy storage stage of the first battery half-discharge winding in this utility model example. Figure 7 This is a schematic diagram of the current path during the discharge stage of the second battery half-pack charging winding in this utility model example. Figure 8 This is a schematic diagram of the current path during the energy storage stage of the second battery half-packed discharge winding in this utility model example. Figure 9 This is a schematic diagram of the current path during the discharge stage of the first battery half-pack charging winding in this utility model example. Figure 10 This is a structural block diagram of the vehicle according to an embodiment of the present utility model. Detailed Implementation

[0019] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0020] The following description, with reference to the accompanying drawings, describes a battery heating and charging system and a vehicle according to embodiments of the present invention.

[0021] Figure 1 This is a structural block diagram of the battery heating and charging system according to an embodiment of the present invention.

[0022] like Figure 1 As shown, the battery heating and charging system 10 includes: a DC charging port 1, a power battery module 2, a first motor drive module 3, and a second motor drive module 4. The power battery module 2 includes a switch assembly 21 and a battery pack 22. The switch assembly 21 is connected to the DC charging port 1, the first motor drive module 3, the second motor drive module 4, and the battery pack 22, respectively. The switch assembly 21 has at least a first working state and a second working state.

[0023] In the first working state, the switch assembly 21 controls the first motor drive module 3 to form a self-heating circuit with the battery pack 22, and the battery pack 22 is self-heated by the first motor drive module 3; in the second working state, the switch assembly 21 controls the DC charging port 1, the second motor drive module 4 and the battery pack 22 to form a boost charging circuit, and the voltage input to the DC charging port 1 is boosted by the second motor drive module 4 to charge the battery pack 22.

[0024] Specifically, in the first operating state, the switching component 21 enables a closed current loop to be formed between the first motor drive module 3 and the battery pack 22. The current output from the battery pack 22 flows through the motor windings in the first motor drive module 3, and Joule heating is generated by the winding resistance to heat the battery pack 22.

[0025] In the second operating state, the switching assembly 21 enables the DC charging port 1 to form a boost charging circuit with the battery pack 22 via the second motor drive module 4. After the DC charging port 1 is connected to an external charging power source, the motor winding in the second motor drive module 4 acts as an energy storage inductor, and the voltage input to the DC charging port 1 is boosted and converted through the interleaved control of the inverter power devices, thereby charging the battery pack 22.

[0026] Optionally, the switch assembly 21 can also enable the DC charging port 1 to form a boost charging circuit with the battery pack 22 through the second motor drive module 4 while forming a closed current loop between the first motor drive module 3 and the battery pack 22, thereby achieving simultaneous heating and charging.

[0027] In this embodiment, the self-heating function of the battery pack 22 is independently undertaken by the first motor drive module 3, and the boost charging function is independently undertaken by the second motor drive module 4. These correspond to different operating states of the switch assembly 21, and the functions can be executed in a time-sharing or simultaneous manner by switching the switch assembly 21. When the two functions are executed in a time-sharing manner, heating and charging do not interfere with each other; when the two functions are executed simultaneously, the self-heating circuit and the boost charging circuit are operated independently by different motor drive modules, physically decoupled, and also do not affect each other. Since the two functions are no longer time-sharing multiplexed by the same motor, time conflicts and efficiency losses caused by alternating heating and charging are avoided. This enables simultaneous heating and charging of the battery pack 22 in low-temperature environments, effectively shortening the low-temperature charging waiting time and improving the user experience. Simultaneously, the switch assembly 21 is integrated inside the power battery module 2, which helps reduce the dispersed arrangement of high-voltage wiring harnesses, simplifies the overall vehicle high-voltage circuit topology, and reduces system complexity and cost.

[0028] In some embodiments of this utility model, the switch assembly 21 also has a third working state; wherein, in the third working state, the switch assembly 21 controls the DC charging port 1 to form a direct charging circuit with the battery pack 22, and the voltage input to the DC charging port 1 directly charges the battery pack 22.

[0029] Specifically, when the output voltage of the external charging pile matches the voltage of the battery pack 22, the switching assembly 21 switches to the third operating state. At this time, the switching assembly 21 controls the direct charging circuit between the DC charging port 1 and the battery pack 22 to be connected, while simultaneously disconnecting the connection between the first motor drive module 3 and the second motor drive module 4 and the battery pack 22 and the DC charging port 1. The external charging power supply directly charges the battery pack 22 through the DC charging port 1, and the charging current does not pass through any motor drive module, avoiding switching losses of power devices and copper losses in the motor windings, thus improving charging efficiency.

[0030] Therefore, the battery heating and charging system in this embodiment can flexibly select various working modes such as direct charging, self-heating, boost charging, or heating and charging coordination according to the voltage level of the external charging pile and the current temperature of the battery pack 22. In low-temperature environments, the battery pack 22 can be self-heated by the first motor drive module 3. When the charging pile voltage is mismatched, boost charging can be performed by the second motor drive module 4. When the charging pile voltage is matched, direct charging can be performed through the direct charging circuit. Thus, while ensuring low-temperature charging performance, it also takes into account the charging efficiency under different charging scenarios, improves the system's compatibility and flexibility, and improves the user experience under different charging conditions.

[0031] In some embodiments of this utility model, such as Figure 2 , Figure 3 As shown, the battery pack 22 includes a first battery half-pack 221 and a second battery half-pack 222, and the first motor drive module 3 includes a first inverter 31 and a first motor 32.

[0032] See Figure 2 , Figure 3 The switching assembly 21 includes a first switch K1, a second switch K2, and a third switch K3. The first end of the first switch K1 is connected to the positive terminal of the first battery half-pack 221, and the second end of the first switch K1 is connected to the positive DC side of the first inverter 31. The first end of the second switch K2 is connected to the negative terminal of the second battery half-pack 222, and the second end of the second switch K2 is connected to the negative DC side of the first inverter 31. The first end of the third switch K3 is connected to the negative terminal of the first battery half-pack 221 and the positive terminal of the second battery half-pack 222, respectively. The second end of the third switch K3 is connected to the connection node between any winding of the first motor 32 and the midpoint of the corresponding inverter bridge arm.

[0033] Specifically, switches K1 and K2 are the positive and negative contactors of the battery pack 22, respectively, and switch K3 is the heating relay or contactor of the battery pack 22. In the first operating state, switch assembly 21 controls K3 to close and controls K1 and K2 to conduct alternately, so that the first battery half-pack 221 and the second battery half-pack 222 alternately discharge and charge, forming an oscillating current in the corresponding winding of the first motor 32, and using the Joule heat generated by the winding resistance to self-heat the battery pack 22.

[0034] It should be noted that the second terminal of the third switch K3 is connected to the connection node between any winding of the first motor 32 and the midpoint of the corresponding inverter bridge arm (i.e., the phase terminal of that phase winding). Since the current only flows through the single-phase winding when connected to the single-phase winding terminal, the entire inductance of that phase winding participates in the energy storage and release process. Compared to connecting to the neutral point shared by all three phase windings, this provides a larger equivalent inductance. A larger inductance means that under the same switching frequency and duty cycle conditions, more magnetic field energy can be stored, and a larger current can be released during the freewheeling phase, thereby increasing the amplitude of the oscillating current, enhancing the winding resistance heating power, and improving the battery self-heating rate.

[0035] In some embodiments of this utility model, such as Figure 2 , Figure 3 As shown, the second motor drive module 4 includes a second inverter 41 and a second motor 42.

[0036] See Figure 2 , Figure 3 The switching assembly 21 also includes a fourth switch K4, a fifth switch K5, and a sixth switch K6. The first end of the fourth switch K4 is connected to the second end of the first switch K1 and the positive DC side of the second inverter 41, respectively. The second end of the fourth switch K4 is connected to the positive DC charging port 1. The first end of the fifth switch K5 is connected to the second end of the second switch K2 and the negative DC side of the second inverter 41, respectively. The second end of the fifth switch K5 is connected to the negative DC charging port 1. The first end of the sixth switch K6 is connected to the positive DC charging port 1. The second end of the sixth switch K6 is connected to the connection node between any winding of the second motor 42 and the midpoint of the corresponding inverter bridge arm.

[0037] Specifically, switches K4 and K5 are the positive relay or contactor relay or negative relay or contactor of DC charging port 1, respectively, and switch K6 is the boost charging relay or contactor. In the second operating state, switch assembly 21 controls K1, K2, K5, and K6 to close, and K3 and K4 to open. At this time, the negative terminal of DC charging port 1 is connected to the negative terminal of battery pack 22 via K5 and K2 in sequence; the positive terminal of DC charging port 1 is connected to the terminal of any phase winding of the second motor 42 via K6, and that phase winding of the second motor 42 and the corresponding inverter bridge arm are connected to the main circuit to participate in the operation as a boost inductor.

[0038] The specific process of boost charging is as follows: The second inverter 41 switches the on and off states of its power devices at high frequency according to the control signal. When the lower bridge arm power device of the second inverter 41 is on, the current input from the DC charging port 1 flows through the phase winding of the second motor 42 and the on-state lower bridge arm power device to form a circuit. At this time, the phase winding stores energy, and the current gradually increases. When the lower bridge arm power device is off and the upper bridge arm power device is on, the magnetic field energy stored in the phase winding is converted into electrical energy, which is superimposed with the voltage input from the DC charging port 1 and output through the DC side of the second inverter 41. The battery pack 22 is charged through the first switch K1 and the second switch K2. By controlling the alternation of the above process at high frequency, the boost charging function can be realized. Compared with the scheme of placing the boost inductor externally in the high-voltage circuit in related technologies, this embodiment reuses the winding inductance of the second motor 42 as the boost inductor, eliminating the need for an additional independent boost inductor device, which helps to reduce the number of components, reduce system cost, and reduce the weight of the vehicle.

[0039] Therefore, the boost charging function of the battery pack 22 is independently executed by the second motor drive module 4. The winding of the second motor 42 is selectively connected to the boost charging circuit through the sixth switch K6, so that the external charging pile can charge the battery pack 22 with a voltage platform mismatch, thereby improving the system's compatibility with charging piles of different voltage levels.

[0040] It should be noted that the second end of the sixth switch K6 is connected to the connection node between any winding of the second motor 42 and the midpoint of the corresponding inverter bridge arm (i.e., the phase end of the phase winding), so that the single-phase winding of the second motor 42 participates in the work as a boost inductor. Compared with the neutral point connected to the three-phase winding, the single-phase winding can provide a larger equivalent inductance, which is beneficial to improving the boost charging efficiency.

[0041] See in some examples Figure 2 The first motor drive module 3 is the front-wheel drive module of the vehicle, and the second motor drive module 4 is the rear-wheel drive module of the vehicle.

[0042] In other examples, see Figure 3 The first motor drive module 3 is a rear-drive module, and the second motor drive module 4 is a front-drive module.

[0043] It should be noted that the first motor drive module 3 and the second motor drive module 4 can also share the same motor drive module. For example, as shown below... Figure 4 As shown, the first motor drive module 3 and the second motor drive module 4 share the front drive module. For example, as... Figure 5 As shown, the first motor drive module 3 and the second motor drive module 4 share the rear drive module.

[0044] Therefore, the battery heating and charging system 10 of this embodiment can be flexibly adjusted according to the actual driving configuration of the vehicle: for vehicles with dual-motor or more motor drive architectures, the first motor drive module 3 and the second motor drive module 4 can independently undertake the self-heating function and the boost charging function, respectively, to achieve decoupling and synergy between the two and improve low-temperature charging efficiency; of course, they can also share the same motor drive module. For vehicles with a single-motor drive architecture, the first motor drive module 3 and the second motor drive module 4 can share the same motor drive module. By switching the switching component 21 between different working states, the motor drive module can simultaneously undertake the self-heating function and the boost charging function, thereby enabling single-motor models to also have battery self-heating and boost charging capabilities without adding additional hardware.

[0045] See in some examples Figures 2 to 5 The power battery module 2 also includes a pre-charge resistor R0 and a first pre-charge switch K01. The pre-charge resistor R0 and the first pre-charge switch K01 are connected in series and then connected in parallel with the first switch K1.

[0046] Specifically, when the system starts up or switches operating states, if the DC side bus capacitor of the first inverter 31 or the second inverter 41 is not charged, directly closing the first switch K1 will cause the bus capacitor to short-circuit instantaneously, generating a large inrush current, which may lead to contactor contact sintering or power device damage.

[0047] By setting a pre-charge resistor R0 and a first pre-charge switch K01, during system power-on or startup, the first pre-charge switch K01 is first closed. External current, after being current-limited by the pre-charge resistor R0, pre-charges the bus capacitor, causing its voltage to gradually rise to near the battery pack voltage. When the bus capacitor voltage reaches a preset threshold, the first switch K1 is then closed, effectively suppressing the inrush current. Subsequently, the first pre-charge switch K01 is opened, causing the pre-charge resistor R0 to exit the working circuit, and the system enters normal operating condition.

[0048] Therefore, the pre-charge resistor R0 and the first pre-charge switch K01 can mitigate overcurrent surges during system startup, protecting the contactor and power devices and improving system reliability and lifespan. Furthermore, since the pre-charge resistor R0 and the first pre-charge switch K01 are integrated within the power battery module 2, there is no need to additionally route a pre-charge circuit in the vehicle's high-voltage circuit, further simplifying the vehicle's wiring.

[0049] In some embodiments of this utility model, such as Figure 2 , Figure 3As shown, the second motor drive module 4 also includes a first pre-charge capacitor C1, a second pre-charge switch K02 and a third pre-charge switch K03. The first pre-charge capacitor C1 and the second pre-charge switch K02 are connected in series between the second end of the sixth switch K6 and the negative DC terminal of the second inverter 41. The first end of the third pre-charge switch K03 is connected to the second end of the sixth switch K6. The second end of the third pre-charge switch K03 is connected to the connection node between any winding of the second motor 42 and the midpoint of the corresponding inverter bridge arm.

[0050] Specifically, the second pre-charge switch K02 and the third pre-charge switch K03 represent boost charging relays or contactors. When boost charging mode is started, switches K5, K02, and K03 are closed first to pre-charge the first pre-charge capacitor C1. When the voltage of the first pre-charge capacitor C1 reaches a preset threshold (for example, more than 90% of the output voltage of DC charging port 1), it indicates that pre-charging is complete. At this time, the sixth switch K6 is closed, so that the winding terminals of the second motor 42 are directly connected to the positive terminal of DC charging port 1, and the system enters the normal operation state of boost charging.

[0051] Therefore, by setting the first pre-charge capacitor C1, the second pre-charge switch K02, and the third pre-charge switch K03, the inrush current during the start-up of the boost charging mode can be suppressed, and the power devices of the sixth switch K6 and the second inverter 41 can be prevented from bearing excessive current stress at the moment of closing, thus preventing contactor contact sintering or power device damage. At the same time, the first pre-charge capacitor C1, the second pre-charge switch K02, and the third pre-charge switch K03 are integrated inside the second motor drive module 4, eliminating the need for additional pre-charge circuits and corresponding wiring harness connectors in the vehicle's high-voltage circuit. This helps reduce the number of high-voltage connection points, lowers wiring harness complexity and the risk of failure due to poor contact, improves system integration and assembly efficiency, and also helps reduce the volume occupied by the vehicle's high-voltage circuit, providing more space for the vehicle's front compartment or chassis layout.

[0052] Accordingly, see Figure 2 , Figure 3 , Figure 4 The first motor drive module 3 also includes a second pre-charge capacitor C2, a fourth pre-charge switch K04 and a fifth pre-charge switch K05, which have the same function as the first pre-charge capacitor C1, the second pre-charge switch K02 and the third pre-charge switch K03.

[0053] In some examples, such as Figures 2 to 5 As shown, the power battery module 2 also includes a first fuse F1 and a second fuse F2.

[0054] See Figures 2 to 5 The first fuse F1 is connected between the positive terminal of the first battery half-pack 221 and the first terminal of the first switch K1, and the second fuse F2 is connected between the negative terminal of the second battery half-pack 222 and the first terminal of the second switch K2.

[0055] In some examples, such as Figures 2 to 4 As shown, the first motor drive module 3 also includes a third fuse F3, which is connected between the positive DC side of the first inverter 31 and the second terminal of the first switch K1; the second motor drive module 4 also includes a fourth fuse F4, which is connected between the positive DC side of the second inverter 41 and the second terminal of the first switch K1.

[0056] By installing the aforementioned fuses, when a short circuit or overcurrent fault occurs in the system, the corresponding fuse can quickly blow, cutting off the faulty circuit and protecting all electrical components from damage caused by high current surges. Furthermore, since each fuse is integrated within its corresponding module, this simplifies the layout of the vehicle's high-voltage wiring harness and reduces system complexity.

[0057] Alternatively, there is another way to heat the battery pack 22: by charging and discharging the battery pack 22 with an external charging station (such as a DC charging station). This method requires the charging station to have bidirectional charging and discharging capabilities and corresponding communication protocol support, which is generally a proprietary protocol of the charging station manufacturer.

[0058] For ease of understanding, the following is based on Figure 2 The illustrated embodiments, in conjunction with Figures 6 to 9 This invention explains the battery self-heating working principle of the battery heating and charging system 10 according to an embodiment of the present invention. Among other things, Figure 6 This is a schematic diagram of the current path during the discharge and winding energy storage stages of the first battery (half-pack 221). Figure 7 This is a schematic diagram of the current path during the charging and winding discharge stages of the second battery half-pack 222. Figure 8 This is a schematic diagram of the current path during the discharge and winding energy storage stages of the second battery's half-pack 222. Figure 9 This is a schematic diagram of the current path during the charging and winding discharge stages of the first battery half-pack 221.

[0059] Specifically, such as Figure 6 As shown, Figure 6As shown, in the first stage (discharging the first battery half-pack 221 and storing energy in the windings), the first switch K1 and the third switch K3 are closed, and the second switch K2 is open. At this time, the positive terminal of the first battery half-pack 221 is connected to the positive DC side of the first inverter 31 via the first switch K1. The upper bridge arm power device of the first inverter 31 (taking the V phase as an example) is turned on, and the current flows sequentially through: the positive terminal of the first battery half-pack 221 → the first switch K1 → the positive DC side of the first inverter 31 → the V phase upper bridge arm → the V phase winding of the first motor 32 → the U phase winding of the first motor 32 → the third switch K3 → the negative terminal of the first battery half-pack 221 (i.e., the battery midpoint), forming a closed loop. During this process, the first battery half-pack 221 discharges, and the current flows through the V phase and U phase windings of the first motor 32. The electrical energy is converted into magnetic field energy and stored in the V phase and U phase windings. At the same time, the winding resistance generates Joule heat, and the temperature of the battery pack 22 begins to rise.

[0060] like Figure 7 As shown, in the second stage (charging of the second battery half-pack 222 and discharging of the windings), the first switch K1 is opened, while the second switch K2 and the third switch K3 remain closed. At this time, the magnetic field energy stored in the V-phase and U-phase windings of the first motor 32 is converted into electrical energy, generating a freewheeling current. The current path is: V-phase winding of the first motor 32 → U-phase winding of the first motor 32 → third switch K3 → positive terminal of the second battery half-pack 222 (i.e., the battery midpoint) → second battery half-pack 222 → negative terminal of the second battery half-pack 222 → second switch K2 → negative DC side of the first inverter 31 → lower bridge arm body diode of the first inverter 31 (corresponding to the lower V-phase bridge arm) → V-phase winding of the first motor 32, forming a freewheeling circuit. During this process, the energy stored in the windings is released, charging the second battery half-pack 222.

[0061] like Figure 8 As shown, in the third stage (discharging the second battery half-pack 222 and storing energy in the windings), the second switch K2 and the third switch K3 are closed, while the first switch K1 is open. At this time, the lower arm power device of the first inverter 31 (taking the V phase as an example) is turned on, and the current flows sequentially through: the positive terminal (i.e., the midpoint of the battery) of the second battery half-pack 222 → the third switch K3 → the U-phase winding of the first motor 32 → the V-phase winding of the first motor 32 → the V-phase lower arm of the first inverter 31 → the DC side negative terminal of the first inverter 31 → the second switch K2 → the negative terminal of the second battery half-pack 222, forming a closed loop. During this process, the second battery half-pack 222 discharges, and the current flows through the U-phase winding of the first motor 32, whereby the electrical energy is again converted into magnetic field energy and stored in the V-phase and U-phase windings.

[0062] like Figure 9As shown, in the fourth stage (charging of the first battery half-pack 221 and discharging of the windings), the second switch K2 is opened, and the first switch K1 and the third switch K3 are closed. At this time, the magnetic field energy stored in the inductance of the V-phase and U-phase windings of the first motor 32 is converted into electrical energy again, generating a freewheeling current. The current path is: U-phase winding of the first motor 32 → V-phase winding of the first motor 32 → V-phase upper bridge arm body diode → DC positive terminal of the first inverter 31 → first switch K1 → positive terminal of the first battery half-pack 221 → first battery half-pack 221 → negative terminal of the first battery half-pack 221 (i.e., the battery midpoint) → third switch K3 → U-phase winding of the first motor 32, forming a freewheeling circuit. During this process, the energy stored in the windings is released, charging the first battery half-pack 221.

[0063] Through the alternating cycles of the above four stages, the first battery half-pack 221 and the second battery half-pack 222 alternately discharge and charge, generating a high-frequency oscillating current in the windings of the first motor 32. The Joule heat generated by the winding resistance self-heats the battery pack 22. By controlling the switching frequency and duty cycle of the inverter power devices, the amplitude and frequency of the oscillating current can be adjusted, thereby achieving precise control of the heating power and enabling the battery pack 22 to rapidly heat up to a suitable operating temperature in low-temperature environments.

[0064] This utility model embodiment also proposes a vehicle.

[0065] like Figure 10 As shown, the vehicle 100 includes: the battery heating and charging system 10 of the above embodiment.

[0066] In summary, the battery heating and charging system and vehicle of this utility model embodiment achieve battery self-heating function by connecting the midpoint of the battery pack to the terminal of one phase winding of the three-phase motor to construct an oscillating current loop; simultaneously, by reusing the inductance of the motor winding and adding a switch, a boost charging circuit is constructed to achieve boost charging function. Compared with related technologies, this utility model can achieve the following beneficial effects: 1) High heating efficiency: By connecting the switching components to the single-phase winding endpoint of the motor (instead of the neutral point connected to the three-phase winding), the equivalent inductance is larger. Under the same switching frequency and duty cycle conditions, it can store more magnetic field energy, release a larger oscillating current, and generate higher heating power from the winding resistance, thereby improving the battery's self-heating rate.

[0067] 2) Decoupled and coordinated heating and charging: By setting up a first motor drive module and a second motor drive module, and using a switching component to switch between different working states, the self-heating function and the boost charging function are executed independently by different motor drive modules, thus achieving decoupling between the two. At the same time, the switching component can also enable the two motor drive modules to work simultaneously, realizing the coordinated execution of heating and charging. In low-temperature environments, heating and charging can be carried out simultaneously, shortening the user's charging waiting time and improving charging efficiency.

[0068] 3) Integration of switch components: By integrating the switch components into the power battery module, it helps to reduce the dispersed layout of high-voltage wiring harnesses, simplify the high-voltage circuit topology, reduce wiring harness connection costs and failure risks, and at the same time, it is beneficial to the spatial layout of the vehicle's front compartment and chassis.

[0069] 4) Strong platform versatility: It can flexibly adapt to vehicles with different drive forms such as single motor, dual motor, front-wheel drive, rear-wheel drive, and four-wheel drive, without the need for differentiated development for different drive forms. It has good platform applicability and market adaptability, which helps reduce the R&D costs of OEMs and the complexity of vehicle configuration management.

[0070] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0072] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0073] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A battery heating and charging system (10), characterized in that, include: DC charging port (1), power battery module (2), first motor drive module (3) and second motor drive module (4), wherein the power battery module (2) includes a switch assembly (21) and a battery pack (22). The switch assembly (21) is connected to the DC charging port (1), the first motor drive module (3), the second motor drive module (4) and the battery pack (22) respectively. The switch assembly (21) has at least a first working state and a second working state. In the first working state, the switch assembly (21) controls the first motor drive module (3) to form a self-heating circuit with the battery pack (22), and the battery pack (22) is self-heated by the first motor drive module (3); in the second working state, the switch assembly (21) controls the DC charging port (1), the second motor drive module (4) and the battery pack (22) to form a boost charging circuit, and the voltage input from the DC charging port (1) is boosted by the second motor drive module (4) to charge the battery pack (22).

2. The battery heating and charging system (10) according to claim 1, characterized in that, The switching assembly (21) also has a third operating state; In the third working state, the switch assembly (21) controls the DC charging port (1) to form a direct charging circuit with the battery pack (22), and the voltage input to the DC charging port (1) directly charges the battery pack (22).

3. The battery heating and charging system (10) according to claim 2, characterized in that, The battery pack (22) includes a first battery half pack (221) and a second battery half pack (222), and the first motor drive module (3) includes a first inverter (31) and a first motor (32). The switching assembly (21) includes a first switch (K1), a second switch (K2), and a third switch (K3). The first end of the first switch (K1) is connected to the positive terminal of the first battery half-pack (221), and the second end of the first switch (K1) is connected to the positive DC side of the first inverter (31). The first end of the second switch (K2) is connected to the negative terminal of the second battery half-pack (222), and the second end of the second switch (K2) is connected to the negative DC side of the first inverter (31). The first end of the third switch (K3) is connected to the negative terminal of the first battery half-pack (221) and the positive terminal of the second battery half-pack (222), respectively. The second end of the third switch (K3) is connected to the connection node between any winding of the first motor (32) and the midpoint of the corresponding inverter bridge arm.

4. The battery heating and charging system (10) according to claim 3, characterized in that, The second motor drive module (4) includes a second inverter (41) and a second motor (42); The switching assembly (21) further includes a fourth switch (K4), a fifth switch (K5), and a sixth switch (K6). The first end of the fourth switch (K4) is connected to the second end of the first switch (K1) and the positive DC side of the second inverter (41), respectively. The second end of the fourth switch (K4) is connected to the positive DC charging port (1). The first end of the fifth switch (K5) is connected to the second end of the second switch (K2) and the negative DC side of the second inverter (41), respectively. The second end of the fifth switch (K5) is connected to the negative DC charging port (1). The first end of the sixth switch (K6) is connected to the positive DC charging port (1). The second end of the sixth switch (K6) is connected to the connection node between any winding of the second motor (42) and the midpoint of the corresponding inverter bridge arm.

5. The battery heating and charging system (10) according to claim 3, characterized in that, The power battery module (2) also includes a pre-charge resistor (R0) and a first pre-charge switch (K01), wherein the pre-charge resistor (R0) and the first pre-charge switch (K01) are connected in series and then connected in parallel with the first switch (K1).

6. The battery heating and charging system (10) according to claim 4, characterized in that, The second motor drive module (4) further includes a first pre-charge capacitor (C1), a second pre-charge switch (K02) and a third pre-charge switch (K03). The first pre-charge capacitor (C1) and the second pre-charge switch (K02) are connected in series between the second end of the sixth switch (K6) and the negative DC terminal of the second inverter (41). The first end of the third pre-charge switch (K03) is connected to the second end of the sixth switch (K6). The second end of the third pre-charge switch (K03) is connected to the connection node between any winding of the second motor (42) and the midpoint of the corresponding inverter bridge arm.

7. The battery heating and charging system (10) according to claim 3, characterized in that, The power battery module (2) also includes a first fuse (F1) and a second fuse (F2); The first fuse (F1) is connected between the positive terminal of the first battery half-pack (221) and the first terminal of the first switch (K1), and the second fuse (F2) is connected between the negative terminal of the second battery half-pack (222) and the first terminal of the second switch (K2).

8. The battery heating and charging system (10) according to claim 4, characterized in that, The first motor drive module (3) also includes a third fuse (F3), which is connected between the positive DC side of the first inverter (31) and the second terminal of the first switch (K1); The second motor drive module (4) also includes a fourth fuse (F4), which is connected between the positive DC side of the second inverter (41) and the second terminal of the first switch (K1).

9. The battery heating and charging system (10) according to any one of claims 1-8, characterized in that, The first motor drive module (3) is the front drive module of the vehicle, and the second motor drive module (4) is the rear drive module of the vehicle. Alternatively, the first motor drive module (3) may be the rear drive module, and the second motor drive module (4) may be the front drive module.

10. A vehicle (100), characterized in that, include: The battery heating and charging system (10) as described in any one of claims 1-9.

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