Battery heating device and vehicle

Abstract

The present disclosure relates to a battery heating device and a vehicle, comprising a controller, a power battery, at least two sets of motor electric control assemblies, the motor electric control assembly comprising a motor winding and a bridge arm converter connected with the motor winding, the power battery comprising at least two battery modules connected in series; the controller is configured to control the two battery modules to alternately discharge when the vehicle is in a heating mode, heat the power battery, and control the upper bridge switch tube and the lower bridge switch tube in the corresponding multi-phase bridge arm of each bridge arm converter to alternately conduct, so as to form an electricity storage loop for the motor winding to store electricity when the battery module is in a discharging state, and form a discharging loop to charge the battery module when the battery module is in a non-discharging state. The two battery modules can be alternately discharged and charged, so that not only the heating of the power battery can be realized, but also the stability of the power battery voltage can be effectively ensured.

Description

Technical Field

[0001] This disclosure relates to the field of battery heating technology, and more specifically, to a battery heating device and a vehicle. Background Technology

[0002] With the development of new energy vehicle technology, users have increasingly higher requirements for the user experience of new energy vehicles. As a key component of new energy vehicles, the battery has the most direct impact on both cost reduction for manufacturers and user experience. New energy vehicle batteries are affected by temperature; at low temperatures, the battery's electrical performance deteriorates, severely affecting the battery pack's discharge performance, leading to problems such as shortened driving range and limited output power during driving. Therefore, it is necessary to heat the battery pack to raise its temperature, thereby ensuring the normal operation of electric vehicles in cold conditions. Summary of the Invention

[0003] The purpose of this disclosure is to provide a battery heating device and a vehicle.

[0004] To achieve the above objectives, the first aspect of this disclosure provides a battery heating device, including a controller, a power battery, and at least two sets of motor control components. The motor control components include motor windings and a bridge arm converter connected to the motor windings. The power battery includes at least two battery modules connected in series.

[0005] The bridge arm converter includes a multi-phase bridge arm, each phase bridge arm includes an upper bridge switch and a lower bridge switch, the motor winding includes a multi-phase winding coil, the midpoint of each phase bridge arm is connected to the first end of a phase winding coil, the second ends of the multi-phase winding coils of the motor winding are connected to each other, and the first and second bus terminals of the multi-phase bridge arm are connected to the positive and negative terminals of the battery module, respectively.

[0006] The controller is configured to, when determining that the current operating mode of the vehicle is heating mode, control the two battery modules to discharge alternately to heat the power battery, and control the upper bridge switch and lower bridge switch in the multi-phase bridge arm corresponding to each bridge arm converter to conduct alternately, so as to form a power storage circuit when the battery module is in the discharging state to store power for the motor winding corresponding to the battery module, and to form a discharge circuit for the motor winding when the battery module is in the non-discharging state to charge the battery module by the motor winding.

[0007] Optionally, the controller is configured to, when determining that the current operating mode of the vehicle is heating mode, if the battery module is in a discharging state, control the upper bridge switch tube in one or more designated bridge arms of the multi-phase bridge arm to be turned on and the lower bridge switch tube to be turned off, and control the lower bridge switch tubes in other bridge arms of the multi-phase bridge arm (excluding the designated bridge arm) to be turned on and the upper bridge switch tubes to be turned off, so as to form the energy storage circuit.

[0008] Optionally, the controller is configured to, when determining that the current operating mode of the vehicle is heating mode, if the battery module is in a non-discharge state, control the upper bridge switch in the designated bridge arm to be turned off and the lower bridge switch to be turned on, and control the upper bridge switch in the other bridge arms of the multi-phase bridge arm (excluding the designated bridge arm) to be turned on and the lower bridge switch to be turned off, so as to form a discharge circuit of the motor winding on the multi-phase winding coil.

[0009] Optionally, the two battery modules connected in series are a first battery module and a second battery module, and the two sets of motor control components are a first motor control component and a second motor control component, respectively.

[0010] Wherein, the first bus terminal of the first motor control component is connected to the positive terminal of the first battery module, and the second bus terminal is connected to the negative terminal of the first battery module and the negative terminal of the second battery module through a first changeover switch; the first bus terminal of the second motor control component is connected to the negative terminal of the second battery module, and the second bus terminal is connected to the positive terminal of the second battery module and the positive terminal of the first battery module through a second changeover switch.

[0011] Optionally, the controller is configured to, when determining that the current operating mode of the vehicle is heating mode, control the first switching switch to be in a first conducting state, so that the negative terminal of the first battery module is connected to the second bus terminal of the first motor control component, and control the second switching switch to be in a second conducting state, so that the positive terminal of the second battery module is connected to the second bus terminal of the second motor control component.

[0012] Optionally, the controller is configured to, when determining that the operating mode is heating mode, acquire the first charging current and first equivalent resistance of the first battery module, the first discharging current and second equivalent resistance of the second battery module, determine a target regulating current based on the first charging current, the first equivalent resistance, the first discharging current and the second equivalent resistance, and control the duty cycle of the first motor control component and / or the second motor control component based on the target regulating current, so as to keep the voltage of the first battery module and the second battery module stable.

[0013] Optionally, the controller is further configured to, when determining that the current operating mode of the vehicle is driving mode, control the first switching switch to be in a second conducting state, so that the negative terminal of the second battery module is connected to the second bus terminal of the first motor control component, and control the second switching switch to be in a first conducting state, so that the positive terminal of the first battery module is connected to the second bus terminal of the second motor control component, and control the first battery module and the second battery module to discharge together to supply power to the first motor control component and the second motor control component, so as to provide driving force to the vehicle.

[0014] Optionally, the controller is further configured to, when determining that the current operating mode of the vehicle is a drive heating mode, control the first switching switch to be in a first conducting state, so that the negative terminal of the first battery module is connected to the second bus terminal of the first motor control component, and control the second switching switch to be in a first conducting state, so that the positive terminal of the first battery module is connected to the second bus terminal of the second motor control component, and control the first battery module and the second battery module to discharge together to supply power to the first motor control component and the second motor control component, so that the second motor control component provides driving force to the vehicle, and the first motor control component heats the first battery module.

[0015] Optionally, the controller is further configured to start timing when both the first and second switching switches are in the first conducting state, and when the timing duration is greater than or equal to a preset timing threshold, control the first switching switch to be in the second conducting state, so that the negative terminal of the second battery module is connected to the second bus terminal of the first motor control component, so that the first motor control component provides driving force to the vehicle, and control the second switching switch to be in the second conducting state, so that the positive terminal of the second battery module is connected to the second bus terminal of the second motor control component, so that the second motor control component heats the second battery module.

[0016] Optionally, it also includes a first switch and a second switch, wherein a first end of the first switch is connected to the positive terminal of the power battery, a second end of the first switch is used to connect to the positive terminal of the charging pile, a first end of the second switch is connected to the negative terminal of the power battery, and a second end of the second switch is used to connect to the negative terminal of the charging pile.

[0017] The controller is configured to, when the operating mode is determined to be the first charging mode, control the first switch and the second switch to close, and control the first changeover switch and the second changeover switch to be in a non-conducting state, so as to form a charging circuit between the power battery and the charging pile.

[0018] Optionally, the controller is further configured to, when determining that the operating mode is the second charging mode, control the first switch and the second switch to close, control the first conversion switch to be in a first conducting state so that the negative terminal of the first battery module is connected to the second bus terminal of the first motor control component, and control the second conversion switch to be in a second conducting state so that the positive terminal of the second battery module is connected to the second bus terminal of the second motor control component.

[0019] A second aspect of this disclosure provides a vehicle that includes the battery heating device described in the first aspect above.

[0020] The above technical solution provides a battery heating device, including a controller, a power battery, and at least two sets of motor control components. Each motor control component includes motor windings and a bridge arm converter connected to the motor windings. The power battery includes at least two battery modules connected in series. The controller, when determining that the vehicle's current operating mode is heating mode, controls the two battery modules to alternately discharge to heat the power battery. It also controls the upper and lower bridge switches in the multi-phase bridge arm corresponding to each bridge arm converter to alternately conduct, forming a storage circuit when the battery module is discharging to store energy in the corresponding motor winding. When the battery module is not discharging, it forms a discharge circuit for the motor winding to charge the battery module. This allows the two battery modules to alternately discharge and charge, thus not only heating the power battery but also effectively ensuring the stability of the power battery voltage.

[0021] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0023] Figure 1 This is a schematic diagram illustrating the principle of internal heating of a battery, as shown in an exemplary embodiment of this disclosure;

[0024] Figure 2 This is a block diagram illustrating a battery heating device according to an exemplary embodiment of the present disclosure;

[0025] Figure 3 It is based on Figure 2 The illustrated embodiment shows a circuit diagram of a battery heating device;

[0026] Figure 4It is based on Figure 2 The illustrated embodiment shows a circuit diagram of another battery heating device;

[0027] Figure 5 It is based on Figure 2 The illustrated embodiment shows a block diagram of a battery heating device;

[0028] Figure 6 It is based on Figure 2 The illustrated embodiment shows a block diagram of another battery heating device;

[0029] Figure 7 This is a circuit diagram illustrating a battery heating device according to another exemplary embodiment of this disclosure;

[0030] Figure 8 It is based on Figure 7 The illustrated embodiment shows a circuit diagram of a battery heating device;

[0031] Figure 9 It is based on Figure 8 The illustrated embodiment shows a circuit diagram of a battery heating device;

[0032] Figure 10 It is based on Figure 8 The illustrated embodiment shows a circuit diagram of another battery heating device. Detailed Implementation

[0033] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0034] Before detailing the specific embodiments of this disclosure, the application scenarios of this disclosure are described below. This disclosure can be applied to battery heating scenarios, such as heating the power battery in a vehicle, and heating the battery in an electronic device in a low-temperature environment. Here, we take heating a power battery as an example. Most vehicle heating methods in related technologies involve using a PTC (Positive Temperature Coefficient) thermistor to heat the battery pack at low temperatures. Its heating principle is that when the battery pack temperature is detected to be too low, the internal switch of the battery heater is turned on, causing the heating resistor to work and generate high temperature. The generated high temperature flows into the battery pack through water channels or air ducts, thereby raising the battery pack temperature. Some vehicles also use internal heating methods. Even if a large current flows through the battery's internal resistance, the internal resistance generates heat (if the battery's equivalent internal resistance is r, the current is i, and the heat generated within time t is i). 2(rt). However, due to the use of external heating, the vehicle's high-voltage system needs to provide additional power to the battery heater (e.g., thermistor), as well as to the water or air ducts, pipelines, and low-voltage system, thus increasing the overall cost. Furthermore, to improve heating speed, the battery heater power is further increased, resulting in high energy loss from the battery pack during heating, leading to rapid SOC depletion in winter driving and a shorter driving range. Additionally, external heating suffers from uneven battery temperature distribution (higher temperatures near the outer edge and heat source, and lower temperatures further away from the heat source and inside the battery pack). Internal battery heating, on the other hand, generates heat not only across the battery's internal resistance but also incurs voltage losses. Figure 1 As shown, Figure 1 This disclosure provides an exemplary embodiment illustrating the principle of internal battery heating; Uocv is the open-circuit voltage of the battery, and r is the equivalent internal resistance of the battery. When current flows from the battery to the outside, equivalent to the battery discharging externally, the battery terminal voltage Uo is Uocv - i*r = Uocv - Ur. When current flows from the outside to the battery, equivalent to the outside charging the battery, the battery terminal voltage Uo is Uocv + i*r = Uocv + Ur. It can be seen that the battery terminal voltage constantly fluctuates between [Uocv - Ur, Uocv + Ur]. Furthermore, with the equivalent internal resistance of the battery remaining constant, the larger the battery current, the greater the voltage fluctuation. This voltage fluctuation can cause the charging pile to be unable to track the battery voltage in real time during direct charging, easily leading to charging failure. In other words, current battery heating solutions typically suffer from low heating efficiency, poor voltage stability, and are detrimental to improving the overall vehicle reliability.

[0035] To address the aforementioned technical problems, this disclosure provides a battery heating device and a vehicle. The battery heating device includes a controller, a power battery, and at least two sets of motor control components. Each motor control component includes motor windings and a bridge arm converter connected to the motor windings. The power battery includes at least two battery modules connected in series. The controller, when determining that the vehicle's current operating mode is heating mode, controls the two battery modules to alternately discharge to heat the power battery. It also controls the upper and lower bridge switches in the multi-phase bridge arm corresponding to each bridge arm converter to alternately conduct, forming a storage circuit when the battery module is discharging to store energy in the corresponding motor winding. When the battery module is not discharging, it forms a discharge circuit for the motor winding to charge the battery module. This allows the two battery modules to alternately discharge and charge, thus not only heating the power battery but also effectively ensuring the stability of the power battery voltage.

[0036] The technical solution of this disclosure will be described in detail below with reference to specific embodiments.

[0037] Figure 2 This is a block diagram illustrating a battery heating device according to an exemplary embodiment of the present disclosure, such as... Figure 2 As shown, the battery heating device may include a controller 201, a power battery 202, and at least two sets of motor control components 203. The motor control components 203 include a motor winding 2031 and a bridge arm converter 2032 connected to the motor winding 2031. The power battery 202 includes at least two battery modules connected in series.

[0038] The bridge arm converter 2032 may include a multi-phase bridge arm, each phase bridge arm including an upper bridge switch and a lower bridge switch. The motor winding 2031 includes a multi-phase winding coil. The midpoint of each phase bridge arm is connected to the first end of a phase winding coil. The second ends of the multi-phase winding coils of the motor winding 2031 are connected to each other. The first and second bus terminals of the multi-phase bridge arm are connected to the positive and negative terminals of the battery module, respectively.

[0039] The controller 201 is used to control the two battery modules to discharge alternately to heat the power battery when the current operating mode of the vehicle is determined to be heating mode, and to control the upper bridge switch and the lower bridge switch in the multi-phase bridge arm corresponding to each bridge arm converter to conduct alternately, so as to form a power storage circuit to store power for the motor winding corresponding to the battery module when the battery module is in the discharge state, and to form a discharge circuit for the motor winding when the battery module is in the non-discharge state, so as to charge the battery module by the motor winding.

[0040] The controller 201 is configured to, when the current operating mode of the vehicle is determined to be heating mode, control the upper bridge switch tube in one or more designated bridge arms of the multi-phase bridge arm to be turned on and the lower bridge switch tube to be turned off if the battery module is in a discharging state, and control the lower bridge switch tube in other bridge arms of the multi-phase bridge arm (excluding the designated bridge arm) to be turned on and the upper bridge switch tube to be turned off, so as to form the energy storage circuit.

[0041] The controller 201 is configured to, when the current operating mode of the vehicle is determined to be heating mode, if the battery module is in a non-discharge state, control the upper bridge switch tube in the designated bridge arm to be turned off and the lower bridge switch tube to be turned on, and control the upper bridge switch tubes in the other bridge arms of the multi-phase bridge arm (excluding the designated bridge arm) to be turned on and the lower bridge switch tubes to be turned off, so as to form a discharge circuit of the motor winding on the multi-phase winding coil.

[0042] For example, Figure 3 It is based on Figure 2The illustrated embodiment shows a circuit diagram of a battery heating device. Figure 4 It is based on Figure 2 The illustrated embodiment shows a circuit diagram of another battery heating device, in Figure 3 The arrow on battery module 1 indicates the direction of current in a type of energy storage circuit. Figure 3 The arrow on battery module 2 indicates the direction of current in a discharge circuit. Figure 4 The arrow on battery module 1 indicates the direction of current in another discharge circuit. Figure 4 The arrow on battery module 2 points in the direction of current in another energy storage circuit, such as... Figure 3 As shown:

[0043] The controller can control the upper bridge switch of bridge arm a1 of bridge arm converter 3 to be turned on and the lower bridge switch to be turned off, and the upper bridge switch of bridge arm b1 and bridge arm c1 of bridge arm converter 3 to be turned off and the lower bridge switch to be turned on, forming Figure 3 The energy storage circuit indicated by the arrow on battery module 1 charges the winding coil in motor winding 4 through this circuit, causing a voltage drop in battery module 1. Simultaneously, the controller can turn on the upper bridge switch of bridge arm a2 of bridge arm converter 6 (since the adjacent parallel diode can also allow current to flow, it can also be turned off), and turn off the lower bridge switch. The upper bridge switches of bridge arms b2 and c2 are also turned off, while the lower bridge switches are turned on, forming... Figure 3 The discharge circuit indicated by the arrow on the battery module 2 allows the motor winding 5 to charge the battery module 2, causing the voltage of the battery module 2 to rise.

[0044] After the preset duration, such as Figure 4 As shown, the controller can control the upper bridge switch of bridge arm a1 of bridge arm converter 3 to be turned off and the lower bridge switch to be turned on, and the upper bridge switch of bridge arm b1 and bridge arm c1 of bridge arm converter 3 to be turned on and the lower bridge switch to be turned off, forming Figure 4 The discharge circuit indicated by the arrow on the battery module 1 charges the battery module 1 through the motor winding 4, causing the voltage of the battery module 1 to rise. Simultaneously, the controller can control the upper bridge switch of bridge arm a2 of the bridge arm converter 6 to be turned off and the lower bridge switch to be turned on, while the upper bridge switches of bridge arms b2 and c2 are turned on and the lower bridge switches are turned off, forming... Figure 4 The energy storage circuit indicated by the arrow on the battery module 2 charges the winding coil in the motor winding 5 through this energy storage circuit, at which time the voltage of the battery module 2 rises.

[0045] It should be noted that the frequency of alternating discharge of the two battery modules is less than the frequency of alternating conduction of the upper and lower bridge switching transistors. The power battery can be formed by two battery modules connected in series, or by three or more battery modules connected in series. The number of cells in different battery modules can be the same or different, and the connection methods of multiple cells in different battery modules can be the same or different. The number of motor and electronic control components included in the battery heating device can be greater than or equal to the number of battery modules. When the number of motor and electronic control components is equal to the number of battery modules, one motor and electronic control component can be connected in parallel across each battery module. When the number of motor and electronic control components is greater than the number of battery modules, multiple motor and electronic control components can be connected in parallel across each battery module. A single motor and electronic control component can also be connected in parallel across a battery pack consisting of multiple battery modules connected in series. For example, in the case of two battery modules and three motor control components, one motor control component can be connected to both ends of one battery module, and two motor control components can be connected to both ends of the other battery module. In the case of two battery modules and four motor control components, two motor control components can be connected in parallel to both ends of each battery module, or one motor control component can be connected to both ends of one battery module, and three motor control components can be connected to both ends of the other battery module.

[0046] The above technical solution enables the two battery modules to alternately discharge and charge in turn, thereby not only heating the power battery but also effectively ensuring the stability of the power battery voltage.

[0047] Optionally, the two battery modules connected in series are a first battery module and a second battery module, and the two sets of motor control components are a first motor control component and a second motor control component, respectively.

[0048] Wherein, the first bus terminal of the first motor control component is connected to the positive terminal of the first battery module, and the second bus terminal is connected to the negative terminal of the first battery module and the negative terminal of the second battery module through a first changeover switch; the first bus terminal of the second motor control component is connected to the negative terminal of the second battery module, and the second bus terminal is connected to the positive terminal of the second battery module and the positive terminal of the first battery module through a second changeover switch.

[0049] The controller 201 is configured to, when determining that the current operating mode of the vehicle is heating mode, control the first switching switch to be in a first conducting state, so that the negative terminal of the first battery module is connected to the second bus terminal of the first motor control component, and control the second switching switch to be in a second conducting state, so that the positive terminal of the second battery module is connected to the second bus terminal of the second motor control component.

[0050] The controller 201 is further configured to, when determining that the current operating mode of the vehicle is driving mode, control the first switching switch to be in a second conducting state, so that the negative terminal of the second battery module is connected to the second bus terminal of the first motor control component, and control the second switching switch to be in a first conducting state, so that the positive terminal of the first battery module is connected to the second bus terminal of the second motor control component, and control the first battery module and the second battery module to discharge together to supply power to the first motor control component and the second motor control component, so as to provide driving force to the vehicle.

[0051] For example, Figure 5 It is based on Figure 2 The illustrated embodiment shows a block diagram of a battery heating device. When the vehicle's current operating mode is determined to be heating mode, the first switching switch 7 is controlled to be in the ab conducting state (first conducting state), so that the motor controller (i.e., the bridge arm converter) 3 is connected in parallel across the two ends of the battery module 1. The second switching switch 8 can also be controlled to be in the ac conducting state (second conducting state), so that the motor controller 9 (and the motor controller 6) are connected in parallel across the two ends of the battery module 2. Simultaneously, according to... Figure 3 and Figure 4 The control method shown controls motor controllers 3, 6, and 9 to heat battery modules 1 and 2. When the vehicle's current operating mode is determined to be drive mode, the first switching switch 7 is controlled to be in the AC conducting state (second conducting state), connecting one end of motor controller (i.e., bridge arm converter) 3 to the positive terminal of battery module 1 and the other end to the negative terminal of battery module 2. The second switching switch 8 is controlled to be in the AB conducting state (first conducting state), connecting one end of motor controller 9 (and motor controller 6) to the positive terminal of battery module 1 and the other end to the negative terminal of battery module 2. Simultaneously, battery modules 1 and 2 are controlled to discharge together, supplying power to motors 4, 5, and 10, so that motors 4, 5, and 10 provide driving force to the vehicle.

[0052] It should be noted that the specific implementation of controlling the arm converter in the first motor control assembly and the second motor control assembly to make the motor rotate can refer to the motor control method in the prior art, which is relatively mature in the prior art, and this disclosure does not limit it.

[0053] The above technical solutions, through the first and second conversion switches, can switch the connection mode between the motor control components and the battery module, thereby enabling the vehicle to flexibly switch between battery family mode and drive mode. They can also reduce the investment cost required for battery heating by reusing the motor windings, thus helping to reduce the overall vehicle manufacturing cost.

[0054] Optionally, the controller 201 is further configured to, when determining that the current operating mode of the vehicle is a drive heating mode, control the first switching switch to be in a first conducting state, so that the negative terminal of the first battery module is connected to the second bus terminal of the first motor control component, and control the second switching switch to be in a first conducting state, so that the positive terminal of the first battery module is connected to the second bus terminal of the second motor control component, and control the first battery module and the second battery module to discharge together to supply power to the first motor control component and the second motor control component, so that the second motor control component provides driving force to the vehicle, and the first motor control component heats the first battery module.

[0055] The controller 201 is further configured to start timing when both the first and second switching switches are in the first conducting state, and when the timing duration is greater than or equal to a preset timing threshold, control the first switching switch to be in the second conducting state, so that the negative terminal of the second battery module is connected to the second bus terminal of the first motor control component, so that the first motor control component provides driving force to the vehicle, and control the second switching switch to be in the second conducting state, so that the positive terminal of the second battery module is connected to the second bus terminal of the second motor control component, so that the second motor control component heats the second battery module.

[0056] For example, Figure 6 It is based on Figure 2 The illustrated embodiment shows a block diagram of another battery heating device, such as Figure 6 As shown, the battery heating device includes battery module 1 and battery module 2. When the first switch 7 is in the ab conducting state (first conducting state), the motor controller (a bridge arm converter) 3 and the motor controller 11 are both connected in parallel across the two ends of battery module 1. When the first switch 7 is in the ac conducting state (second conducting state), the motor controller (a bridge arm converter) 3 and the motor controller 11 are both connected in parallel across the two ends of the power battery (battery module 1 and battery module 2 connected in series). When the second switch 8 is in the ac conducting state (second conducting state), the motor controller (a bridge arm converter) 6 and the motor controller 9 are both connected in parallel across the two ends of battery module 2. When the second switch 8 is in the ab conducting state (first conducting state), the motor controller (a bridge arm converter) 6 and the motor controller 9 are both connected in parallel across the two ends of the power battery (battery module 1 and battery module 2 connected in series).

[0057] When the controller determines that the current operating mode of the vehicle is the drive heating mode, it controls the first conversion switch 7 to be in the ab conducting state, so that the motor controller 3 controls the motor 4 to enter the heating mode, and the motor controller 11 controls the motor 12 to enter the heating mode. At the same time, it controls the second conversion switch 8 to be in the ab conducting state, so that the motor controller 6 and the motor controller 9 are connected in parallel across the two ends of the power battery (battery module 1 and battery module 2 are connected in series), and controls the first battery module and the second battery module to discharge together to supply power to the motor controller 6 and the motor controller 9, so that the motor controller 6 controls the motor 5 to rotate, and the motor controller 9 controls the motor 10 to rotate, providing driving force to the vehicle. The controller is also used to start timing when both the first and second switch are in the ab conducting state. When the timing duration is greater than or equal to a preset timing threshold, it controls the first switch 7 to be in the ac conducting state. The motor controller (a bridge arm converter) 3 and motor controller 11 are connected in parallel across the power battery (battery module 1 and battery module 2 connected in series), and the first and second battery modules discharge together to supply power to the motor controller 3 and motor controller 11, so that the motor controller 3 controls the motor 4 to rotate, and the motor controller 11 controls the motor 12 to rotate, providing driving force to the vehicle. Simultaneously, it controls the second switch 8 to be in the ac conducting state, so that the motor controller (a bridge arm converter) 6 and motor controller 9 are both connected in parallel across the battery module 2 to heat the battery module 2. It should be noted that due to the alternating conduction states of the first switch 7 and the second switch 8, the energy storage and discharge of the motor windings can be realized, completing the charging process of the battery module. The process of forming the energy storage circuit and the discharge circuit can be found in [reference needed]. Figure 3 and Figure 4 The descriptions in the document are not repeated here.

[0058] The above technical solutions can effectively achieve oscillation heating of the power battery during driving, which can not only effectively improve the battery heating efficiency, but also ensure the stability of the power battery voltage, thus improving the reliability of vehicle driving.

[0059] Optionally, the controller 201 is configured to, when the operating mode is determined to be heating mode, acquire the first charging current and first equivalent resistance of the first battery module, the first discharging current and second equivalent resistance of the second battery module, determine a target regulating current based on the first charging current, the first equivalent resistance, the first discharging current and the second equivalent resistance, and control the duty cycle of the first motor control component and / or the second motor control component based on the target regulating current, so as to keep the voltage of the first battery module and the second battery module stable.

[0060] The target regulating current can be either the current intensity that the first battery module needs to reduce or the current intensity that the second battery module needs to increase. The duty cycle of the bridge arm converter in the first motor control assembly and / or the duty cycle of the bridge arm converter in the second motor control assembly are controlled according to the target regulating current, so that the voltage rise of the first battery module is equal to the voltage drop of the second battery module, thereby ensuring that the voltages of the first battery module and the second battery module remain stable.

[0061] For example, with Figure 2 For example, in timing sequence one, the voltage of battery module 2 continuously increases, with an increase of ΔU2 = I2 * R. cell2 I2 is the first charging current, R cell2 As the first equivalent resistance, the voltage of battery module 1 continuously decreases, with a decrease magnitude ΔU1 = I1*R. cell1 Where I1 is the first discharge current, R cell1 For the second equivalent resistance, in R cell1 =R cell2 Under the premise that the duty cycle of the first motor control component and / or the second motor control component is controlled so that the output first discharge current I1 is equal to the first charging current I2, the voltage drop of battery module 1 can be made equal to the voltage rise of battery module 2, thereby ensuring that the total voltage fluctuation of the power battery 202 is 0, that is, ensuring that the voltage of battery module 1 and battery module 2 remains stable. Similarly, in timing two, the voltage of battery module 1 continuously rises, with an increase of ΔU2 = I2 * R. cell2 The voltage of battery module 2 continues to decrease, with a decrease of ΔU1 = I1 * R. cell1 R cell1 =R cell2 Under the premise that the duty cycle of the first motor control component and / or the second motor control component is controlled so that the output first discharge current I1 is equal to the first charging current I2, the voltage drop of battery module 1 can be made equal to the voltage rise of battery module 2, thereby ensuring that the total voltage fluctuation of the power battery 202 is 0. In R cell1 >R cell2 In this case, by controlling the duty cycle of the first motor control component and / or the second motor control component, the output first discharge current I1 is made less than the first charging current I2, I1 / I2 = R cell2 / R cell1 To ensure that ΔU1 = ΔU2, the voltage drop of battery module 1 is equal to the voltage rise of battery module 2, resulting in zero total voltage fluctuation in power battery 202; in R cell1 <R cell2In this case, by controlling the duty cycle of the first motor control component and / or the second motor control component, the output first discharge current I1 is made greater than the first charging current I2, I1 / I2 = R cell2 / R cell1 To ensure that ΔU1 = ΔU2, the voltage drop of battery module 1 is equal to the voltage rise of battery module 2, and the total voltage fluctuation of power battery 202 is 0.

[0062] The above technical solutions can ensure that the voltage rise and fall amplitudes are equal in both battery modules, thereby ensuring the stability of the total voltage of the power battery and effectively improving the stability of the power battery voltage during battery heating.

[0063] Optionally, it also includes a first switch and a second switch, wherein a first end of the first switch is connected to the positive terminal of the power battery, a second end of the first switch is used to connect to the positive terminal of the charging pile, a first end of the second switch is connected to the negative terminal of the power battery, and a second end of the second switch is used to connect to the negative terminal of the charging pile.

[0064] The controller 201 is used to control the first switch and the second switch to close and control the first changeover switch and the second changeover switch to be in a non-conducting state when the operating mode is determined to be the first charging mode, so as to form a charging circuit between the power battery and the charging pile.

[0065] The first charging mode is a simple charging mode, in which the power battery is not heated, such as... Figure 7 As shown, Figure 7 This is a circuit diagram illustrating a battery heating device according to another exemplary embodiment of this disclosure. Figure 7 When the first switch 10 and the second switch 9 are closed, the first changeover switch 7 and the second changeover switch 8 are in a non-conducting state (i.e., neither ab nor ac are in a conducting state, but are in a floating state). Figure 7 The direction of the current indicated by the middle arrow is the direction of current flow when the DC charging pile charges the power battery.

[0066] Optionally, the controller 201 is further configured to, when the operating mode is determined to be the second charging mode, control the first switch and the second switch to close, control the first conversion switch to be in a first conducting state so that the negative terminal of the first battery module is connected to the second bus terminal of the first motor control component, and control the second conversion switch to be in a second conducting state so that the positive terminal of the second battery module is connected to the second bus terminal of the second motor control component.

[0067] In this second charging mode, the power battery is simultaneously being charged via a DC charging station and heated.

[0068] For example, Figure 8 It is based on Figure 7 The illustrated embodiment shows a circuit diagram of a battery heating device. Figure 8 The first switch 10 and the second switch 9 are closed, while the first changeover switch 7 is in the ab conducting state and the second changeover switch 8 is in the ac conducting state. The duty cycle of the bridge arm converter is adjusted to change the storage current when the motor winding stores electricity. When this storage current is greater than the current output by the DC charging pile, electricity is stored in the motor winding. For example, the duty cycle can be adjusted to... Figure 9 ( Figure 9 It is based on Figure 8 The circuit diagram of a battery heating device shown in the embodiment illustrates that the clockwise current in the battery module 1 increases, thereby storing electricity in the motor winding 4 to heat the battery module 1. The heating effect can be achieved by adjusting the duty cycle. Figure 10 ( Figure 10 It is based on Figure 8 In the circuit diagram of another battery heating device shown in the embodiment, the clockwise current in the battery module 2 increases, thereby storing electricity in the motor winding 5 and heating the battery module 2.

[0069] The above technical solutions can heat the power battery while the vehicle is in charging mode, which helps to improve the charging efficiency of the power battery and thus greatly enhances the user experience.

[0070] Another exemplary embodiment of this disclosure provides a vehicle, the vehicle comprising the above... Figures 2 to 10 The battery heating device described herein.

[0071] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0072] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0073] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A battery heating device, characterized in that, It includes a controller, a power battery, and at least two sets of motor control components. The motor control components include motor windings and a bridge arm converter connected to the motor windings. The power battery includes at least two battery modules connected in series. The bridge arm converter includes a multi-phase bridge arm, each phase bridge arm includes an upper bridge switch and a lower bridge switch, the motor winding includes a multi-phase winding coil, the midpoint of each phase bridge arm is connected to the first end of a phase winding coil, the second ends of the multi-phase winding coils of the motor winding are connected to each other, and the first and second bus terminals of the multi-phase bridge arm are connected to the positive and negative terminals of the battery module, respectively. The controller is configured to, when determining that the current operating mode of the vehicle is heating mode, control the two battery modules to discharge alternately to heat the power battery, and control the upper bridge switch and lower bridge switch in the multi-phase bridge arm corresponding to each bridge arm converter to conduct alternately, so as to form a power storage circuit when the battery module is in the discharging state to store power for the motor winding corresponding to the battery module, and to form a discharge circuit for the motor winding when the battery module is in the non-discharging state to charge the battery module by the motor winding.

2. The battery heating device according to claim 1, characterized in that, The controller is configured to, when the current operating mode of the vehicle is determined to be heating mode, and if the battery module is in a discharging state, control the upper bridge switch in one or more designated bridge arms of the multi-phase bridge arm to be turned on and the lower bridge switch to be turned off, and control the lower bridge switch in other bridge arms of the multi-phase bridge arm (excluding the designated bridge arm) to be turned on and the upper bridge switch to be turned off, so as to form the energy storage circuit.

3. The battery heating device according to claim 2, characterized in that, The controller is configured to, when the current operating mode of the vehicle is determined to be heating mode, if the battery module is in a non-discharge state, control the upper bridge switch in the designated bridge arm to be turned off and the lower bridge switch to be turned on, and control the upper bridge switch in the other bridge arms of the multi-phase bridge arm (excluding the designated bridge arm) to be turned on and the lower bridge switch to be turned off, so as to form a discharge circuit of the motor winding on the multi-phase winding coil.

4. The battery heating device according to claim 1, characterized in that, The two battery modules connected in series are the first battery module and the second battery module, and the two sets of motor control components are the first motor control component and the second motor control component, respectively. Wherein, the first bus terminal of the first motor control component is connected to the positive terminal of the first battery module, and the second bus terminal is connected to the negative terminal of the first battery module and the negative terminal of the second battery module through a first changeover switch; the first bus terminal of the second motor control component is connected to the negative terminal of the second battery module, and the second bus terminal is connected to the positive terminal of the second battery module and the positive terminal of the first battery module through a second changeover switch.

5. The battery heating device according to claim 4, characterized in that, The controller is configured to, when determining that the current operating mode of the vehicle is heating mode, control the first switching switch to be in a first conducting state, so that the negative terminal of the first battery module is connected to the second bus terminal of the first motor control component, and control the second switching switch to be in a second conducting state, so that the positive terminal of the second battery module is connected to the second bus terminal of the second motor control component.

6. The battery heating device according to claim 4, characterized in that, The controller is configured to, when the operating mode is determined to be heating mode, acquire the first charging current and first equivalent resistance of the first battery module, the first discharging current and second equivalent resistance of the second battery module, determine a target regulating current based on the first charging current, the first equivalent resistance, the first discharging current and the second equivalent resistance, and control the duty cycle of the first motor control component and / or the second motor control component based on the target regulating current, so as to keep the voltage of the first battery module and the second battery module stable.

7. The battery heating device according to claim 4, characterized in that, The controller is further configured to, when determining that the current operating mode of the vehicle is driving mode, control the first switching switch to be in a second conducting state, so that the negative terminal of the second battery module is connected to the second bus terminal of the first motor control component, and control the second switching switch to be in a first conducting state, so that the positive terminal of the first battery module is connected to the second bus terminal of the second motor control component, and control the first battery module and the second battery module to discharge together to supply power to the first motor control component and the second motor control component, so as to provide driving force to the vehicle.

8. The battery heating device according to claim 4, characterized in that, The controller is further configured to, when determining that the current operating mode of the vehicle is drive heating mode, control the first conversion switch to be in a first conducting state, so that the negative terminal of the first battery module is connected to the second bus terminal of the first motor control component, and control the second conversion switch to be in a first conducting state, so that the positive terminal of the first battery module is connected to the second bus terminal of the second motor control component, and control the first battery module and the second battery module to discharge together to supply power to the first motor control component and the second motor control component, so that the second motor control component provides driving force to the vehicle, and the first motor control component heats the first battery module.

9. The battery heating device according to claim 8, characterized in that, The controller is further configured to start timing when both the first and second switching switches are in the first conducting state, and when the timing duration is greater than or equal to a preset timing threshold, control the first switching switch to be in the second conducting state, so that the negative terminal of the second battery module is connected to the second bus terminal of the first motor control component, so that the first motor control component provides driving force to the vehicle, and control the second switching switch to be in the second conducting state, so that the positive terminal of the second battery module is connected to the second bus terminal of the second motor control component, so that the second motor control component heats the second battery module.

10. The battery heating device according to claim 4, characterized in that, It also includes a first switch and a second switch. The first end of the first switch is connected to the positive terminal of the power battery, and the second end of the first switch is used to connect to the positive terminal of the charging pile. The first end of the second switch is connected to the negative terminal of the power battery, and the second end of the second switch is used to connect to the negative terminal of the charging pile. The controller is configured to, when the operating mode is determined to be the first charging mode, control the first switch and the second switch to close, and control the first changeover switch and the second changeover switch to be in a non-conducting state, so as to form a charging circuit between the power battery and the charging pile.

11. The battery heating device according to claim 10, characterized in that, The controller is further configured to, when the operating mode is determined to be the second charging mode, control the first switch and the second switch to close, control the first conversion switch to be in a first conducting state so that the negative terminal of the first battery module is connected to the second bus terminal of the first motor control component, and control the second conversion switch to be in a second conducting state so that the positive terminal of the second battery module is connected to the second bus terminal of the second motor control component.

12. A vehicle, characterized in that, The vehicle includes the battery heating device as described in any one of claims 1-11.

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