powertrain, motor controller, control device, electric vehicle

Abstract

The application discloses a power assembly, a motor controller, a motor controller control device and an electric vehicle. The power assembly is used for heating a power battery of the electric vehicle. The working modes of the power assembly include a battery internal resistance heating mode and a driving motor heating mode. The power assembly can be operated in different working modes according to different conditions and the heating power in each working mode can be adjusted. The motor controller can output high-frequency pulse current or motor excitation current to heat the power battery. The motor controller can output the high-frequency pulse current or the motor excitation current according to different conditions. The motor controller control device controls the motor controller to output the pulse current or the motor excitation current by controlling the on-off of each switch tube of the three bridge arms of the motor controller. The power assembly, the motor controller, the motor controller control device and the electric vehicle disclosed by the application can improve the power battery heating efficiency and the energy utilization efficiency of the electric vehicle.

Description

Technical Field

[0001] This application relates to the field of power battery thermal management, and more particularly to an electric vehicle powertrain, a motor controller, a control device for the motor controller, and an electric vehicle. Background Technology

[0002] Currently, the main methods for heating power batteries include positive temperature coefficient (PTC) resistance heating, motor excitation current heating, and high-frequency pulse current heating. PTC resistance heating requires additional electronic components, thus incurring problems such as component redundancy and structural complexity. Motor excitation current heating suffers from excessively long heat transfer paths and low heating efficiency. High-frequency pulse current heating results in significant motor vibration and noise. Therefore, using only a single heating method for power batteries leads to low heating efficiency and low energy utilization of electric vehicles. Summary of the Invention

[0003] This application provides a powertrain, a motor controller, and an electric vehicle, which are beneficial to improving the heating efficiency of the electric vehicle's power battery and the energy utilization efficiency of the electric vehicle.

[0004] In a first aspect, embodiments of this application provide a powertrain. The powertrain includes a drive motor and a motor controller. The motor controller receives power from a power battery and outputs a high-frequency pulse current or a motor excitation current to the drive motor. The drive motor heats the power battery via a heat conduction device. The powertrain operates in two modes: a battery internal resistance heating mode and a drive motor heating mode. The motor controller outputs a high-frequency pulse current to the drive motor to operate the powertrain in the battery internal resistance heating mode. The motor controller also outputs a motor excitation current to the drive motor to operate the powertrain in the drive motor heating mode. The powertrain selects between the battery internal resistance heating mode and the drive motor heating mode based on a temperature parameter. The temperature parameter is the temperature of at least one of the drive motor, the power battery, or the heat conduction device.

[0005] In this embodiment, the powertrain has two operating modes: battery internal resistance heating and drive motor heating. The powertrain can select different modes to heat the power battery, thereby achieving different heating methods for different scenarios and avoiding the drawbacks of each heating method. Therefore, the powertrain provided in this application can combine the advantages of different power battery heating methods to improve battery heating efficiency.

[0006] In one implementation of the first aspect, the powertrain operates in a battery internal resistance heating mode when the temperature parameter is lower than a preset temperature threshold. Conversely, the powertrain operates in a drive motor heating mode when the temperature parameter is higher than the preset temperature threshold.

[0007] In one implementation of the first aspect, the powertrain switches its operating mode from the battery internal resistance heating mode to the drive motor heating mode in response to the powertrain operating in the battery internal resistance heating mode for a period of time exceeding a preset duration.

[0008] In this implementation, the powertrain can select different heating modes based on at least one of the drive motor temperature, battery temperature, and heat transfer device temperature, or the duration of operation in the battery internal resistance heating mode. At lower temperatures, the powertrain operates in the battery internal resistance heating mode with higher heating power to increase the battery's temperature rise rate. At higher temperatures, the powertrain operates in the drive motor heating mode with lower heating power to save energy and prevent battery overheating. Therefore, this implementation can improve the energy utilization efficiency of electric vehicles and protect the battery.

[0009] In one implementation of the first aspect, the powertrain reduces its heating power in the battery internal resistance heating mode in response to an increase in temperature parameters when operating in the battery internal resistance heating mode. Similarly, the powertrain reduces its heating power in the drive motor heating mode in response to an increase in temperature parameters when operating in the drive motor heating mode.

[0010] In one implementation of the first aspect, the powertrain reduces the heating power of the powertrain in the battery internal resistance heating mode or the drive motor heating mode in response to the duration of the powertrain operating in the battery internal resistance heating mode or the drive motor heating mode.

[0011] In one implementation of the first aspect, the heating power of the powertrain operating in the battery internal resistance heating mode is greater than the heating power of the powertrain operating in the drive motor heating mode.

[0012] In this implementation, during the process of the powertrain heating the power battery, the battery temperature continuously increases with the increase of temperature parameters and heating time. The heating power of the powertrain during the heating process of the power battery decreases with the increase of temperature parameters or heating time to avoid battery overheating, which can protect the power battery. At the same time, by reducing the heating power with the increase of temperature parameters and heating time, energy consumption can be reduced and energy utilization efficiency can be improved.

[0013] In one implementation of the first aspect, the heat transfer device includes a drive motor thermal circuit, a power battery thermal circuit, and a heat exchanger. The drive motor thermal circuit is used to absorb the heat generated by the drive motor, the power battery thermal circuit is used to heat the power battery, and the heat from the drive motor thermal circuit is transferred to the power battery thermal circuit through the heat exchanger.

[0014] Secondly, embodiments of this application provide a motor controller for a drive motor. The drive motor includes three-phase windings and is used to heat a power battery via a heat conduction device. The motor controller includes a bridge arm circuit consisting of three parallel bridge arms. The two ends of each bridge arm are respectively connected to the positive and negative terminals of the power battery, and the midpoints of the three bridge arms are respectively connected to the three-phase windings of the drive motor. In response to a temperature parameter being less than a preset temperature threshold, the motor controller outputs a high-frequency pulse current from the midpoint of at least one bridge arm of the bridge arm circuit to one phase winding of the drive motor to which it is connected. In response to a temperature parameter being greater than the preset temperature threshold, the motor controller outputs a three-phase alternating current from the midpoints of the three bridge arms of the bridge arm circuit to the three-phase windings of the drive motor. The three-phase alternating current causes the drive motor torque to be zero and the motor excitation current to be greater than zero.

[0015] The temperature parameter is the temperature of at least one of the drive motor, power battery, or heat transfer device.

[0016] In one implementation of the second aspect, the motor controller reduces the frequency of the high-frequency pulse current in response to the duration of the high-frequency pulse current output by the motor controller. The motor controller reduces either the frequency or amplitude of the high-frequency pulse current, or reduces the amplitude of the excitation current, in response to an increase in temperature parameters. The motor controller reduces the amplitude of the excitation current in response to the duration of operation in the excitation current mode.

[0017] In one implementation of the second aspect, each bridge arm circuit includes an upper bridge arm switch and a lower bridge arm switch connected in series. One end of the upper bridge arm switch is used to connect to the positive terminal of the power battery, and the other end of the upper bridge arm switch is connected to one end of the lower bridge arm switch to form the midpoint of each bridge arm. The other end of the lower bridge arm switch is used to connect to the negative terminal of the power battery.

[0018] Thirdly, embodiments of this application provide a control device for a motor controller. The motor controller receives power from a power battery and drives a drive motor to operate or generate heat. The motor controller includes a bridge arm circuit consisting of three bridge arms connected in parallel. Each bridge arm includes an upper bridge arm switch and a lower bridge arm switch connected in series. The two ends of each bridge arm are respectively used to connect to the positive and negative terminals of the power battery. The midpoints of the three bridge arms are respectively used to connect to the three-phase windings of the drive motor. In response to a temperature parameter being less than a preset temperature threshold, the control device controls the upper bridge arm switch of at least one bridge arm and the lower bridge arm switch of at least another bridge arm to simultaneously turn on and off. In response to a temperature parameter being greater than the preset temperature threshold, the control device controls the three bridge arms to form a three-phase full-bridge inverter circuit. The temperature parameter is the temperature of at least one of the drive motor, the power battery, or a heat transfer device.

[0019] In one implementation of the third aspect, the control device, in response to the duration of the high-frequency pulse current output at the midpoint of each of the three bridge arms of the bridge arm circuit, reduces the frequency and duty cycle of the simultaneous on and off of the upper bridge arm switch and the lower bridge arm switch of at least one of the three bridge arms. The control device, in response to the duration of the motor excitation current output by the three bridge arms of the bridge arm circuit, reduces the amplitude of the three-phase AC current output by the three bridge arms of the bridge arm circuit. The control device, in response to a rise in temperature parameters, reduces the frequency or duty cycle of the alternating switching of the upper and lower bridge arm switches of any one bridge arm, or reduces the amplitude of the three-phase AC current output by the three bridge arms of the bridge arm circuit.

[0020] In one implementation of the third aspect, the control device is used to control the three-phase current output of the three bridge arms of the bridge arm circuit to drive the motor. The control device is used to control the three-phase AC current output of the three bridge arms of the motor controller bridge arm circuit as the drive current of the motor. The control device controls the switching of the six switching transistors of the three bridge arms of the motor controller so that the direct-axis current and quadrature-axis current of the drive current of the motor are both greater than zero.

[0021] In one implementation of the third aspect, the control device receives either an acceleration command or a heating command. In response to the acceleration command, the control device controls the motor controller to drive the drive motor. In response to the heating command, the control device controls the motor controller to drive the drive motor to heat the battery.

[0022] Fourthly, embodiments of this application provide an electric vehicle. The electric vehicle includes a powertrain as described in the first aspect, a motor controller as described in the second aspect, or a motor controller control device as described in the third aspect.

[0023] In one implementation of the fourth aspect, the vehicle controller is used to send acceleration commands or heating commands to the motor controller or control device.

[0024] For the technical effects achievable by any possible design in the second aspect above, please refer to the description of the technical effects achievable by any possible design in the first aspect above. For the technical effects achievable by any possible design in the third aspect, please refer to the description of the technical effects achievable by any possible design in the first and second aspects above. For the technical effects achievable by any possible design in the fourth aspect, please refer to the description of the technical effects achievable by any possible design in the first, second, and third aspects above, and will not be repeated here. Attached Figure Description

[0025] Figure 1 A schematic diagram of an electric vehicle provided for an embodiment of this application;

[0026] Figure 2 A schematic diagram of a heat conduction device provided in an embodiment of this application;

[0027] Figure 3 A schematic diagram of an electric vehicle powertrain provided in an embodiment of this application;

[0028] Figure 4 A schematic diagram of a motor controller provided in an embodiment of this application;

[0029] Figure 5 A schematic diagram of a control device for a motor controller provided in an embodiment of this application;

[0030] Figure 6 A schematic diagram of powertrain operation provided in an embodiment of this application;

[0031] Figure 7 A schematic diagram of powertrain operation provided in an embodiment of this application;

[0032] Figure 8 A schematic diagram of the operation of a control device provided in an embodiment of this application; Detailed Implementation

[0033] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0034] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0035] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0036] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0037] Electric vehicles are powered by batteries. Temperature has a significant impact on batteries. Charging and discharging batteries at low temperatures can lead to lithium plating, causing capacity degradation and even safety hazards. Therefore, batteries must be heated to a certain temperature before the vehicle can be driven.

[0038] Electric vehicles mainly use three methods to heat the power battery, among which:

[0039] One method of heating a power battery involves using an external heating system. For example, a power battery thermal circuit is installed outside the battery, containing a heat-carrying fluid. A positive temperature coefficient resistor (PTC) heats the heat-carrying fluid in the thermal circuit, which then conducts the heat to the battery. However, this method requires heating the heat-carrying fluid in the thermal circuit first, and then using that fluid to heat the battery, resulting in a long heat transfer path and low heating efficiency.

[0040] One method of heating a power battery involves using the excitation current of a motor to generate heat in the drive motor, which then heats the battery. The motor controller outputs three-phase AC power to the drive motor, resulting in zero torque in the drive motor but a non-zero excitation current. This excitation current generates heat in the drive motor windings, which is then conducted to the power battery via a heat transfer device between the drive motor and the battery. However, this method suffers from drawbacks due to the need for the heat from the drive motor to be transferred to the battery via a heat transfer device. These drawbacks include a long heat transfer path, low battery heating rate, and low heating efficiency.

[0041] One method of heating a power battery utilizes a high-frequency pulsed current generated by a motor controller. The motor controller's bridge arm circuit generates a high-frequency pulsed current, which, when passing through the power battery, generates heat on the battery's internal resistance, thus heating the battery. This heating method has the advantage of a fast heating rate; however, the high-frequency pulsed current passing through the drive motor results in significant noise and vibration from the drive motor.

[0042] Based on this, embodiments of this application provide an electric vehicle powertrain, a motor controller, and a control device for the motor controller. The powertrain uses different heating methods in combination based on temperature threshold conditions or duration threshold conditions to heat the power battery, thereby avoiding the drawbacks of different power battery heating methods and improving the heating efficiency and energy utilization efficiency of the power battery. The electric vehicle powertrain, motor controller, and control device are described in detail below with reference to specific embodiments.

[0043] Figure 1 This is a schematic diagram of an electric vehicle provided as an embodiment of this application. (For example...) Figure 1As shown, the electric vehicle includes a powertrain 20, a power battery 10, a heat transfer device 21, and a vehicle controller 24. The powertrain 20 is used to drive the electric vehicle or to heat the power battery 10. The powertrain 20 includes a drive motor 23 and a motor controller 22. The motor controller 22 is used to operate the drive motor 23 or generate heat in response to acceleration or heating commands from the vehicle controller 24. The heat generated by the drive motor 23 is conducted to the power battery 10 through the heat transfer device 21 to heat the power battery 10.

[0044] Figure 2 This is a schematic diagram of a heat transfer device for an electric vehicle provided in an embodiment of this application. Figure 2 As shown, the heat transfer device 21 is located between the drive motor 23 and the power battery 10, and is used for heat exchange between the drive motor 23 and the power battery 10. The heat transfer device 21 includes a drive motor thermal circuit 216, a power battery thermal circuit 217, and a heat exchanger 213. The drive motor thermal circuit 216 absorbs the heat generated by the drive motor 23, and the power battery thermal circuit 217 heats the power battery 10. The heat from the drive motor thermal circuit 216 is transferred to the power battery thermal circuit 217 through the heat exchanger 213. The drive motor thermal circuit 216 includes a pump 211 and a pipe 214. The power battery thermal circuit 217 includes a pump 212 and a pipe 215.

[0045] For example, the drive motor thermal circuit 216 is used to conduct heat generated on the drive motor 23 to the heat carrier fluid of the drive motor thermal circuit 216, and the power battery thermal circuit 217 is used to conduct heat from the heat carrier fluid of the power battery thermal circuit 217 to the power battery. Pump 211 is used to adjust the flow rate and pressure of the heat carrier fluid in the drive motor thermal circuit 216, and pump 212 is used to adjust the flow rate and pressure of the heat carrier fluid in the power battery thermal circuit 217. Heat exchanger 213 is used to exchange heat between the drive motor thermal circuit 216 and the power battery circuit 217.

[0046] The heat generated by the drive motor 23 of the powertrain 20 provided in this application embodiment can be transferred to the power battery 10 through the heat conduction device 21, so that the heat generated by the drive motor 23 can be used to heat the power battery 10. This can avoid the problem of the drive motor 23 overheating during the operation of the powertrain 20, and can also make full use of the heat generated by the drive motor 23 to heat the power battery 10.

[0047] In one embodiment, the heat transfer fluid in the drive motor thermal circuit 216 is a coolant. In another embodiment, the heat transfer fluid in the drive motor thermal circuit 216 is lubricating oil, and the heat exchanger 213 is an oil cooler.

[0048] Figure 3This is a schematic diagram of a powertrain provided in an embodiment of this application. Figure 3 As shown, the powertrain 20 includes a drive motor 23 and a motor controller 22. The motor controller 22 receives power from the power battery 10 and outputs a high-frequency pulse current or motor excitation current to the drive motor 23 for heating the power battery 10. The drive motor 23 heats the power battery 10 through the heat conduction device 21.

[0049] In this embodiment, the powertrain 20 operates in two modes: a battery internal resistance heating mode and a drive motor heating mode. The powertrain 20 selects to operate in either the battery internal resistance heating mode or the drive motor heating mode based on the temperature of at least one of the drive motor 23, the power battery 10, or the heat transfer device 21. In the battery internal resistance heating mode, the motor controller 22 outputs a high-frequency pulse current to the drive motor 23. In the drive motor heating mode, the motor controller 22 outputs a motor excitation current to the drive motor 23.

[0050] In this embodiment, the powertrain 20 operates in battery internal resistance heating mode. The motor controller 22 receives power from the power battery 10 and outputs a high-frequency pulse current to the drive motor 23. The high-frequency pulse current generates a large amount of Joule heat on the internal resistance of the power battery 10 to heat the battery.

[0051] In this embodiment, the powertrain 20 operates in a drive motor heating mode. The motor controller 22 receives power from the power battery 10 and outputs motor excitation current to the drive motor 23. The motor excitation current generates heat on the drive motor windings. The heat generated on the drive motor windings 23 is conducted to the power battery 10 through the heat conduction device 21.

[0052] In this embodiment, the heating power of the powertrain 20 operating in the battery internal resistance heating mode is greater than the heating power of the powertrain 20 operating in the drive motor 23 heating mode. When the powertrain 20 operates in the battery internal resistance heating mode, the high-frequency pulse current directly heats the battery 10 from inside, resulting in a shorter heat transfer path and thus higher heating efficiency for the power battery 10. Furthermore, the effective value of the high-frequency pulse current is greater than the motor excitation current; therefore, the heating power of the powertrain 20 is higher when operating in the battery internal resistance heating mode, and the heating rate of the power battery 10 is faster.

[0053] The powertrain 20 provided in this application embodiment can not only heat the power battery 10 by using the excitation current of the motor to heat the winding of the drive motor 23, but also heat the power battery 10 from the inside by using high-frequency pulse current, thereby improving the battery heating efficiency and the energy utilization efficiency of the electric vehicle.

[0054] The motor controller 22 provided in this embodiment includes three parallel bridge arms, which together form a bridge arm circuit 221. Each bridge arm includes an upper bridge arm switch and a lower bridge arm switch connected in series. One end of the upper bridge arm switch in each bridge arm is connected to the positive terminal of the power battery 10. The other end of the upper bridge arm switch in each bridge arm is connected to one end of the lower bridge arm switch to form the midpoint of each bridge arm. The other end of the lower bridge arm switch in each bridge arm is connected to the negative terminal of the power battery 10. The midpoints of the three bridge arms are respectively used to connect to the three-phase windings of the drive motor 23.

[0055] like Figure 4 As shown, the motor controller 22 includes a bridge arm circuit 221 consisting of three bridge arms connected in parallel. The two ends of each bridge arm of the bridge arm circuit 221 are connected to the positive and negative terminals of the power battery 10, respectively. The two ends of each bridge arm of the bridge arm circuit 221 are also connected to the two ends of the bus capacitor C1. The midpoints of the three bridge arms are connected to the three windings L1, L2, and L3 of the drive motor 23, respectively.

[0056] like Figure 4 As shown, the first bridge arm includes an upper bridge arm switch tube 201 and a lower bridge arm switch tube 202. The second bridge arm includes an upper bridge arm switch tube 203 and a lower bridge arm switch tube 204. The third bridge arm includes an upper bridge arm switch tube 205 and a lower bridge arm switch tube 206.

[0057] In this embodiment, the switching transistor can be one or more of various types of switching transistors, such as metal oxide semiconductor field effect transistor (MOSFET) and insulated gate bipolar transistor (IGBT). These types will not be listed one by one in this embodiment.

[0058] In this embodiment, the switching transistor includes a first electrode, a second electrode, and a control electrode. The control electrode of the switching transistor is used to control whether the switching transistor is turned on or off. When the switching transistor is on, current can be transmitted between the first and second electrodes. When the switching transistor is off, no current can be transmitted between the first and second electrodes.

[0059] In this embodiment, the bridge arm circuit 221 outputs a high-frequency pulse current or a motor excitation current to heat the power battery 10. In one embodiment, the bridge arm circuit 221 outputs a high-frequency pulse current, which generates a large amount of heat on the internal resistance of the power battery 10. In another embodiment, the motor controller 22 outputs a motor excitation current, and the bridge arm circuit 221 outputs three-phase AC power at the midpoint of the three bridge arms, causing the drive motor 23 to not output torque and the motor excitation current to be non-zero. The motor excitation current generates heat on the drive motor 23, and the heat conduction device 21 conducts the heat generated on the drive motor 23 to the power battery 10.

[0060] like Figure 5 As shown, Figure 5 This is a schematic diagram of a control device for a motor controller proposed in this application. The output terminal of the control device 222 is used to connect to the control electrodes of the upper bridge arm switch tube and the lower bridge arm switch tube of each of the three bridge arms and output control signals to control the conduction and cutoff of the three upper bridge arm switch tubes (201, 203, 205) and the three lower bridge arm switch tubes (202, 204, 206).

[0061] In this embodiment, the control device 222 controls the bridge arm circuit 221 of the motor controller 22 to output a high-frequency pulse current by outputting a high-frequency pulse current control signal. The high-frequency pulse current is used to generate heat on the internal resistance of the power battery 10.

[0062] In this embodiment, the control device 222 controls the bridge arm circuit 221 of the motor controller 22 to output three-phase AC power by outputting the motor excitation current control signal, so that the torque of the drive motor 23 is zero and the excitation current is greater than zero. The excitation current generates heat on the drive motor 23, and the heat conduction device 21 conducts the heat generated on the drive motor 23 to the power battery 10.

[0063] In one embodiment, the control device 222 sends a high-frequency pulse current signal, the bridge arm circuit 221 of the motor controller 22 outputs a high-frequency pulse current, and the powertrain 20 operates in the battery internal resistance heating mode, whereby the high-frequency pulse current generates heat on the internal resistance of the power battery 10.

[0064] In one embodiment, the control device 222 sends a motor excitation current signal, and the bridge arm circuit 221 outputs three-phase AC power. The three-phase AC power makes the output torque of the drive motor 23 zero and the excitation current non-zero. The excitation current generates heat on the winding of the drive motor 23, and the heat conduction device 21 conducts the heat generated on the drive motor 23 to the power battery 10.

[0065] The operation of the powertrain, motor controller, and control device provided in the embodiments of this application will be further explained below.

[0066] In this embodiment, the powertrain 20 is used to select between battery internal resistance heating mode and drive motor heating mode based on temperature parameters. The temperature parameters are at least one of the following: power battery temperature, drive motor temperature, and heat transfer device temperature.

[0067] In one embodiment, the power battery temperature is the power battery cell temperature. In one embodiment, the power battery temperature is the power battery surface temperature. In one embodiment, the drive motor temperature is the drive motor rotor temperature. In one embodiment, the drive motor temperature is the drive motor stator temperature. In one embodiment, the drive motor temperature is the drive motor ambient temperature. In one embodiment, the heat conduction device temperature is the temperature of the heat transfer fluid in the drive motor's thermal circuit. In one embodiment, the heat conduction device temperature is the temperature of the heat transfer fluid in the power battery's thermal circuit.

[0068] In this embodiment, the powertrain 20 operates in battery internal resistance heating mode in response to temperature parameters being less than a preset temperature threshold, and operates in drive motor heating mode in response to temperature parameters being greater than a preset temperature threshold.

[0069] In one embodiment, the preset temperature threshold is a preset power battery temperature threshold. For example, the preset power battery temperature threshold is -20 degrees Celsius. When the power battery temperature is below -20 degrees Celsius, the power assembly 20 indicates that the power battery 10 temperature is too low. An excessively low power battery temperature can lead to severe capacity degradation, low charging power, or even failure to charge. In response to the power battery temperature being below the preset temperature threshold, the power assembly 20 operates in a battery internal resistance heating mode with higher heating power, causing the power battery 10 temperature to rise more quickly, thereby protecting the power battery 10 and increasing its charging power.

[0070] When the power battery temperature exceeds -20 degrees Celsius, the capacity degradation of power battery 10 is relatively small, and power battery 10 can be charged normally. Correspondingly, in response to the power battery temperature exceeding -20 degrees Celsius, powertrain 20 operates in a drive motor heating mode with lower heating power to prevent power battery 10 from overheating.

[0071] In this embodiment, the powertrain 20 is used to switch the powertrain to operate in battery heating mode or battery internal resistance heating mode according to temperature parameters.

[0072] In one embodiment, the powertrain 20 operates in a battery internal resistance heating mode. As the battery temperature rises, it exceeds a preset battery temperature threshold. At this point, the battery temperature has reached a relatively high value. To prevent the battery from overheating, the powertrain 20 switches its operating mode from the battery internal resistance heating mode with higher heating power to the drive motor heating mode with lower heating power.

[0073] In one embodiment, the powertrain 20 operates in a battery internal resistance heating mode. The high-frequency pulse current generates heat on the drive motor 23, causing the drive motor temperature to exceed a preset drive motor temperature threshold. The powertrain 20 then switches its operating mode from the battery internal resistance heating mode to the drive motor heating mode to prevent the drive motor 23 from overheating.

[0074] In one embodiment, the powertrain 20 operates in a battery internal resistance heating mode. When the temperature of the drive motor is greater than a preset drive motor temperature threshold and the temperature of the power battery is greater than a preset power battery temperature threshold, the operating mode of the powertrain 20 switches from the battery internal resistance heating mode to the drive motor heating mode to protect the drive motor 23 and the power battery 10.

[0075] In one embodiment, the powertrain 20 operates in a battery internal resistance heating mode, whereby heat generated in the power battery 10 and the drive motor 23 is conducted to the heat transfer device 10, causing the temperature of the heat transfer fluid in the drive motor thermal circuit 216 and the power battery thermal circuit 217 of the heat transfer device 21 to increase. of The temperature of the heat transfer fluid increases. Therefore, the higher the temperature of the heat transfer fluid in the drive motor thermal circuit 216 or the power battery thermal circuit, the higher the temperature of the drive motor 23 or the power battery 10. If the temperature of the heat transfer fluid in the drive motor thermal circuit 216 or the power battery thermal circuit exceeds the preset value, there is a risk of overheating in the drive motor 23 or the power battery 10. The powertrain 20 will switch its operating mode from the battery internal resistance heating mode with higher heating power to the drive motor heating mode with lower heating power.

[0076] In this embodiment, in response to the fact that the duration of the powertrain 20 operating in the battery internal resistance heating mode exceeds a preset duration, the operating mode of the powertrain 20 is switched from the battery internal resistance heating mode to the drive motor 23 heating mode.

[0077] In one embodiment, if the powertrain 20 operates in the battery internal resistance heating mode for a period exceeding a preset time, the temperature of the power battery 10 rises, posing a risk of overheating. Therefore, the powertrain 20 switches its operating mode from the battery internal resistance heating mode with higher heating power to the drive motor heating mode with lower heating power to avoid battery overheating.

[0078] For example, the preset duration of the powertrain 20 operating in the battery internal resistance heating mode is 20 minutes. In response to the powertrain 20 operating in the battery internal resistance heating mode for more than one minute, the powertrain 20 switches its operating mode from the battery internal resistance heating mode to the drive motor heating mode.

[0079] In this embodiment, the powertrain 20 reduces its heating power in the battery internal resistance heating mode in response to an increase in temperature parameters when the powertrain 20 is operating in the drive motor heating mode. The powertrain 20 also reduces its heating power in the drive motor 23 heating mode in response to an increase in temperature parameters when the powertrain 20 is operating in the drive motor heating mode.

[0080] During the heating process of the power battery 10 by the powertrain 20, the temperatures of the drive motor, the power battery, and the heat transfer device will all rise. If the temperature of the power battery or the drive motor rises too quickly, there is a risk of overheating of the drive motor 23 or the power battery 10. Therefore, in order to protect the drive motor 23 or the power battery 10, when the powertrain is operating in the battery internal resistance heating mode or the drive motor heating mode, the powertrain 20 adjusts the heating power to decrease as the temperature parameters rise.

[0081] In one embodiment, when the powertrain 20 operates in the battery internal resistance heating mode, the temperature parameter rises, and the powertrain 20 reduces the heating power when operating in the battery internal resistance heating mode.

[0082] In one embodiment, when the powertrain 20 operates in the drive motor heating mode, the temperature parameter rises, and the powertrain 20 reduces the heating power when operating in the drive motor heating mode.

[0083] In this embodiment, the heating power of the powertrain 20 decreases as the temperature parameter increases, and the powertrain 20 is used to adjust the functional relationship between the heating power and the temperature parameter.

[0084] like Figure 6 As shown, in one embodiment, the heating power of the powertrain 20 decreases linearly with the increase of temperature parameters or the increase of the duration of operation of the powertrain 20 in battery internal resistance heating mode or drive motor heating mode.

[0085] like Figure 7 As shown, in one embodiment, the heating power of the powertrain 20 decreases in stages as the temperature parameter increases or as the duration of operation of the powertrain 20 in battery internal resistance heating mode or drive motor heating mode increases.

[0086] In this embodiment, the duration of the powertrain 20 operating in the battery internal resistance heating mode or the drive motor 23 heating mode is increased, and the powertrain 20 is used to reduce the heating power of the powertrain 20 operating in the battery internal resistance heating mode or the drive motor 23 heating mode.

[0087] In this embodiment, as the duration of the powertrain 20 operating in the battery internal resistance heating mode or the drive motor heating mode increases, the temperature of the drive motor and the power battery continuously rises, posing a risk of overheating to the drive motor 23 and the power battery 10. In order to protect the drive motor 23 and the power battery, the powertrain 20 reduces the heating power of the powertrain 20 operating in the battery internal resistance heating mode or the drive motor 23 heating mode.

[0088] In one embodiment, the powertrain 20 reduces its heating power in response to an increase in the duration of operation of the powertrain 20 in the battery internal resistance heating mode.

[0089] In one embodiment, the powertrain 20 reduces heating power in response to the duration of operation of the powertrain 20 in drive motor heating mode.

[0090] In this embodiment, the motor controller 22 heats the power battery 10 by outputting a high-frequency pulse current or a motor excitation current through the bridge arm circuit 221. Specifically, the bridge arm circuit 221 outputs a high-frequency pulse current from the midpoint of at least one bridge arm to one phase winding of the drive motor 23 connected thereto. The high-frequency pulse current generates heat on the internal resistance of the power battery 10, thus heating the power battery 10. The midpoint of the bridge arm circuit 221 outputs a three-phase AC current to the three-phase winding of the drive motor 23. The three-phase AC current makes the torque of the drive motor 23 zero and the motor excitation current greater than zero. The motor excitation current generates heat on the three-phase winding of the drive motor 23, and the heat conduction device 21 conducts the heat generated on the drive motor 23 to the power battery 10.

[0091] In this embodiment, in response to a temperature parameter being less than a preset temperature threshold, the motor controller 22 outputs a high-frequency pulse current from the midpoint of at least one bridge arm to a phase winding of the drive motor 23 to which it is connected. In response to a temperature parameter being greater than the preset temperature threshold, the motor controller 22 outputs a three-phase AC current from the midpoints of the three bridge arms of the bridge arm circuit 221 to the three-phase winding of the drive motor 23. This three-phase AC current causes the torque of the drive motor 23 to be zero and the motor excitation current to be greater than zero. The temperature parameter is the temperature of at least one of the drive motor 23, the power battery 10, or the heat transfer device. In one embodiment, the preset temperature threshold is a preset power battery temperature threshold. In one embodiment, the preset temperature threshold is a preset drive motor temperature threshold. In one embodiment, the preset temperature threshold is a preset heat transfer device temperature threshold.

[0092] In this embodiment, the motor controller 22 switches the bridge arm circuit 221 from outputting high-frequency pulse current to outputting motor excitation current in response to the temperature parameter being greater than a preset temperature threshold.

[0093] In one embodiment, the bridge arm circuit 221 outputs a high-frequency pulse current when the power battery temperature exceeds a preset power battery temperature threshold. At this time, the power battery temperature has risen to a relatively high value. To prevent the power battery 10 from overheating, the bridge arm circuit 221 switches from outputting a high-frequency pulse current to outputting a motor excitation current.

[0094] In one embodiment, the bridge arm circuit 221 outputs a high-frequency pulse current. When the temperature of the driving motor is greater than a preset driving motor temperature threshold, the bridge arm circuit 221 switches from outputting a high-frequency pulse current to outputting a motor excitation current.

[0095] In one embodiment, the bridge arm circuit 221 outputs a high-frequency pulse current. When the temperature of the drive motor is greater than a preset drive motor temperature threshold and the temperature of the power battery is greater than a preset power battery temperature threshold, the bridge arm circuit 221 switches from outputting a high-frequency pulse current to outputting a motor excitation current.

[0096] In one embodiment, the bridge arm circuit 221 outputs a high-frequency pulse current. When the temperature of the heat conduction device is greater than the preset temperature of the heat conduction device, the bridge arm circuit 221 switches from outputting a high-frequency pulse current to outputting a motor excitation current.

[0097] In this embodiment of the application, the duration of the high-frequency pulse current output by the bridge arm circuit 221 exceeds the preset duration, and the bridge arm circuit 221 switches from outputting high-frequency pulse current to outputting motor excitation current.

[0098] In this embodiment, the motor controller 22 reduces the frequency and amplitude of the high-frequency pulse current or the effective value of the motor excitation current in response to an increase in temperature parameters. During the process of the motor controller 22 outputting the high-frequency pulse current or the motor excitation current to heat the power battery 10, the temperatures of the drive motor 23 and the power battery rise rapidly, posing a risk of overheating to both the drive motor 23 and the power battery 10. To protect the drive motor 23 and the power battery 10, the motor controller 22 reduces the heating power of the high-frequency pulse current on the internal resistance of the power battery 10 by reducing the frequency and amplitude of the high-frequency pulse current, and also reduces the effective value of the motor excitation current or the heating power of the motor excitation current on the motor windings.

[0099] In one embodiment, in response to a rise in temperature parameters when the bridge arm circuit 221 outputs a high-frequency pulse current, the motor controller 22 reduces the frequency or amplitude of the high-frequency pulse current to reduce the heat generation power of the high-frequency pulse current on the battery internal resistance. In another embodiment, in response to a rise in temperature parameters when the bridge arm circuit 221 outputs a motor excitation current, the motor controller 22 reduces the effective value of the motor excitation current mode to reduce the heat generation power of the motor excitation current on the motor windings.

[0100] In this embodiment, the control device 222 is used to control the output of high-frequency pulse current or motor excitation current of the six switching transistors of the bridge arm circuit 221.

[0101] In one embodiment, the control device 222 controls the six switches of the bridge arm circuit 221 to output high-frequency pulse current. The control device 222 determines the pulse frequency and duty cycle based on the current temperature of the power battery 10. The duty cycle refers to the conduction time of the switches corresponding to the three bridge arms of the bridge arm circuit 221 during the discharge of the power battery 10, i.e., the process of current flowing from the positive terminal to the negative terminal of the power battery 10. That is, when the power battery 10 discharges, at least one upper bridge arm switch of the three bridge arms must be turned on and at least one lower bridge arm switch of the other bridge arm must be turned on simultaneously. Therefore, the duty cycle is the ratio of the time during which at least one upper bridge arm switch of the three bridge arms is turned on and at least one lower bridge arm switch of the other bridge arm is turned on simultaneously to the time during which they are simultaneously turned off in one cycle. Based on the pulse frequency and duty cycle, the controller device 222 generates a high-frequency pulse current output by the bridge arm circuit 221. The high-frequency pulse current generates Joule heat on the internal resistance of the power battery 10 to increase the temperature of the power battery 10.

[0102] like Figure 8 As shown, Figure 8 This diagram shows the PWM (Pulse Width Modulation) drive signal, the current of the single-phase L1 of the drive motor 23, and the charging and discharging current of the power battery 10 when the duty cycle is equal to 0.5.

[0103] In one embodiment, the control device 222 controls the output motor excitation current of the six switches in the bridge arm circuit 221. The controller device 222 determines the heating power based on the current temperature of the power battery 10. The control device 222 controls the output of three-phase AC current from the midpoint of the three bridge arms of the motor controller 22 to the three-phase windings of the drive motor 23 according to the heating power. The three-phase AC current makes the torque of the drive motor 23 zero and the motor excitation current greater than zero. The motor excitation current generates heat in the windings of the drive motor 23 and conducts the heat to the power battery 10 through the heat conduction device 21. Specifically, according to the motor torque output formula, the control device 222 can make the output torque of the drive motor 23 zero by controlling the direct-axis current component of the three-phase AC current.

[0104] In this embodiment, the control device 222 controls the six switches of the bridge arm circuit 221 to output a high-frequency pulse current in response to a temperature parameter being less than a preset temperature threshold, and controls the six switches of the bridge arm circuit 221 to output a motor excitation current in response to a temperature parameter being greater than the preset temperature threshold. In one embodiment, the preset temperature threshold is a preset power battery temperature threshold. In one embodiment, the preset temperature threshold is a preset drive motor temperature threshold. In one embodiment, the preset temperature threshold is a preset heat conduction device temperature threshold.

[0105] In one embodiment, in response to a rise in temperature parameters when the bridge arm circuit 221 outputs a high-frequency pulse current, the control device 222 reduces the frequency and duty cycle of simultaneously turning on and off the upper bridge arm switch and the lower bridge arm switch of at least one of the three bridge arms of the motor controller 22, thereby reducing the heat generation power of the high-frequency pulse current on the battery's internal resistance. The control device 222 controls the motor controller 22 to output a high-frequency pulse current, which causes the power battery temperature to rise rapidly, posing a risk of overheating to the power battery 10. To protect the power battery 10, the control device 222 reduces the frequency and duty cycle of alternating switching of at least one upper bridge arm switch and at least one lower bridge arm switch in the bridge arm circuit 221 to reduce the heat generation power of the high-frequency pulse current on the internal resistance of the power battery 10, thereby reducing the rate of temperature rise of the power battery.

[0106] In one embodiment, in response to an increase in the duration of the high-frequency pulse current output by the bridge arm circuit 221, the control device 222 reduces the frequency and duty cycle of the simultaneous on / off of the upper bridge arm switch of at least one bridge arm and the lower bridge arm switch of at least another bridge arm in the bridge arm circuit 221, thereby reducing the heat generation power of the high-frequency pulse current on the battery's internal resistance. As the duration of the high-frequency pulse current output by the three bridge arms of the motor controller 23 controlled by the control device 222 increases, the temperature of the power battery 10 continuously rises, posing a risk of overheating. To protect the power battery 10, the control device 222 reduces the frequency and duty cycle of the simultaneous on / off of the upper bridge arm switch of at least one bridge arm and the lower bridge arm switch of at least another bridge arm in the bridge arm circuit 221 to reduce the heat generation power of the high-frequency pulse current on the internal resistance of the power battery 10, thereby reducing the rate of temperature rise of the power battery.

[0107] In one embodiment, in response to a rise in temperature parameters when the bridge arm circuit 221 outputs motor excitation current, the control device 222 reduces the effective value of the three-phase AC current output at the midpoint of the three bridge arms of the bridge arm circuit 221, thereby reducing the heat generation power of the motor excitation current on the windings of the drive motor 23. The control device 222 controls the motor controller 22 to output the motor excitation current, which causes the power battery temperature to rise rapidly, posing a risk of overheating to the power battery 10. To protect the power battery 10, the control device 222 reduces the effective value of the three-phase AC current, thereby reducing the effective value of the motor excitation current, and consequently reducing the heat generation power of the motor excitation current on the windings of the drive motor 23, thus decreasing the rate of temperature rise of the power battery.

[0108] In one embodiment, in response to an increase in the duration of the control device 222 controlling the motor controller 22 to output the motor excitation current, the control device 222 reduces the effective value of the three-phase AC power output by the three bridge arms, thereby reducing the heat generation power of the motor excitation current on the windings of the drive motor 23. As the duration of the control device 222 controlling the six switches of the bridge arm circuit 221 to output the motor excitation current increases, the temperature of the power battery 10 continuously rises, posing a risk of overheating. To protect the power battery 10, the control device 222 reduces the effective value of the three-phase AC power, thereby reducing the effective value of the motor excitation current, and consequently reducing the heat generation power of the motor excitation current on the windings of the drive motor 23, thus reducing the rate of temperature rise of the power battery.

[0109] In this embodiment, the control device 222 is used to receive an acceleration command to operate the drive motor 23 or to receive a heating command to heat the power battery 10. In one embodiment, the control device 222 controls the motor controller 22 to operate the drive motor 23 in response to the acceleration command. In another embodiment, the control device 222 controls the motor controller 22 to heat the battery in response to the heating command. For example, the vehicle controller 24 sends an acceleration command to the control device 222, and the control device 222 controls the motor controller 22 to output three-phase AC power with both torque current and excitation current greater than zero to the drive motor 23. The three-phase AC power causes the drive motor 23 to operate, thereby enabling the electric vehicle to run. For example, the vehicle controller 24 sends a heating command to the control device 222, and the control device 222 controls the motor controller 22 to output a high-frequency pulse current, causing the powertrain 20 to operate in a battery internal resistance heating mode to heat the power battery 10. For example, the vehicle controller 24 sends a heating command to the control device 222, and the control device 222 controls the motor controller 22 to output excitation current, so that the powertrain 20 operates in the drive motor heating mode to heat the power battery 10.

[0110] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Although the preferred embodiments of this application have been disclosed above, they are not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A powertrain, characterized in that, The powertrain includes a drive motor and a motor controller. The motor controller receives power from the power battery and outputs a high-frequency pulse current or a motor excitation current to the drive motor. The drive motor heats the power battery through a heat conduction device. The powertrain operates in two modes: a battery internal resistance heating mode and a drive motor heating mode. The powertrain selects between the battery internal resistance heating mode and the drive motor heating mode based on temperature parameters. In response to the temperature parameter being less than a preset temperature threshold, the motor controller outputs the high-frequency pulse current to the drive motor to make the powertrain operate in the battery internal resistance heating mode. The high-frequency pulse current is used to generate a current with a periodically changing direction on the internal resistance of the power battery. In response to the temperature parameter being greater than the preset temperature threshold, the motor controller outputs three-phase AC power to the drive motor to make the powertrain operate in the drive motor heating mode, wherein the three-phase AC power makes the drive motor torque zero and the motor excitation current greater than zero. The temperature parameter is the temperature of at least one of the drive motor, the power battery, or the heat conduction device.

2. The powertrain according to claim 1, characterized in that, The powertrain is used for: In response to the powertrain operating in the battery internal resistance heating mode for a duration exceeding a preset duration, the powertrain's operating mode is switched from the battery internal resistance heating mode to the drive motor heating mode.

3. The powertrain according to claim 1, characterized in that, The powertrain is used for: In response to an increase in temperature parameters while operating in the battery internal resistance heating mode, the heating power while operating in the battery internal resistance heating mode is reduced; or In response to an increase in temperature parameters while operating in the drive motor heating mode, the heating power while operating in the drive motor heating mode is reduced.

4. The powertrain according to claim 1, characterized in that, The powertrain is used for: In response to the duration of the powertrain operating in the battery internal resistance heating mode or the drive motor heating mode, the heating power of the powertrain operating in the battery internal resistance heating mode or the drive motor heating mode is reduced.

5. The powertrain according to any one of claims 1-4, characterized in that, The heating power of the powertrain when operating in the battery internal resistance heating mode is greater than the heating power of the powertrain when operating in the drive motor heating mode.

6. The powertrain according to claim 1, characterized in that, The heat conduction device includes a drive motor thermal circuit, a power battery thermal circuit, and a heat exchanger. The drive motor thermal circuit is used to absorb the heat generated by the drive motor, and the power battery thermal circuit is used to heat the power battery. The heat from the drive motor thermal circuit is conducted to the power battery thermal circuit through the heat exchanger.

7. A motor controller for driving a motor, characterized in that, The motor controller includes a bridge arm circuit consisting of three parallel bridge arms. Each bridge arm has two ends connected to the positive and negative terminals of the power battery, respectively. The midpoints of the three bridge arms are connected to the three-phase windings of the drive motor. The drive motor includes three-phase windings and is used to heat the power battery via a heat conduction device. The motor controller is used for: In response to a temperature parameter being less than a preset temperature threshold, the bridge arm circuit outputs a high-frequency pulse current to one phase winding of the drive motor to which it is connected. The high-frequency pulse current is used to generate a current with a periodically changing direction across the internal resistance of the power battery. In response to the temperature parameter being greater than the preset temperature threshold, the midpoint of the bridge arm circuit outputs three-phase AC power to the three-phase winding of the drive motor, and the three-phase AC power makes the torque of the drive motor zero and the excitation current of the motor greater than zero. The temperature parameter is the temperature of at least one of the drive motor, the power battery, or the heat conduction device.

8. The motor controller according to claim 7, characterized in that, The motor controller is used for: In response to the duration of the high-frequency pulse current output by the motor controller, the frequency or amplitude of the high-frequency pulse current is reduced; or, In response to an increase in the temperature parameter, reduce either the frequency or amplitude of the high-frequency pulse current, or reduce the amplitude of the excitation current; or, In response to the duration of the motor controller outputting the motor excitation current, the amplitude of the motor excitation current is reduced.

9. The motor controller according to any one of claims 7-8, characterized in that, Each of the bridge arms includes an upper bridge arm switch and a lower bridge arm switch connected in series. One end of the upper bridge arm switch is used to connect to the positive terminal of the power battery, and the other end of the upper bridge arm switch is connected to one end of the lower bridge arm switch to form the midpoint of each bridge arm. The other end of the lower bridge arm switch is used to connect to the negative terminal of the power battery.

10. A control device for a motor controller, characterized in that, The motor controller is used to receive power from the power battery and drive the drive motor to operate or generate heat. The motor controller includes a bridge arm circuit consisting of three bridge arms connected in parallel. Each bridge arm includes an upper bridge arm switch and a lower bridge arm switch connected in series. The two ends of each bridge arm are respectively used to connect to the positive and negative terminals of the power battery. The midpoints of the three bridge arms are respectively used to connect to the three-phase windings of the drive motor. The control device is used for: In response to the temperature parameter being less than a preset temperature threshold, the upper bridge arm switch of at least one of the three bridge arms and the lower bridge arm switch of at least another bridge arm are simultaneously turned on and off, causing the motor controller to output a high-frequency pulse current. The high-frequency pulse current is used to generate a current with a periodically changing direction on the internal resistance of the power battery. In response to the temperature parameter being greater than a preset temperature threshold, the three bridge arms are controlled to form an inverter circuit so that the motor controller outputs three-phase AC power so that the torque of the drive motor is zero and the excitation current of the drive motor is greater than zero. The temperature parameter is the temperature of at least one of the drive motor or the power battery.

11. The control device according to claim 10, characterized in that, The control device is used for; In response to the duration of high-frequency pulse current output at the midpoint of each of the three bridge arms, the frequency and duty cycle of simultaneous on / off of the upper bridge arm switch of at least one bridge arm and the lower bridge arm switch of at least another bridge arm are reduced; or, In response to the duration of the motor excitation current output by the three bridge arms, the effective value of the three-phase AC output of the three bridge arms is reduced; or In response to the rise in temperature parameter, reduce the frequency or duty cycle at which the upper bridge arm switch of at least one of the three bridge arms and the lower bridge arm switch of at least another bridge arm are simultaneously turned on and off, or reduce the effective value of the three-phase AC output of the three bridge arms.

12. The control device according to claim 10, characterized in that, The control device is used to control the three bridge arms to output three-phase current to drive the drive motor to operate. The control device is used for: The control device controls the three bridge arms to output three-phase AC power as the drive current for the motor. The control device controls the switching of the six switches in the three bridge arms so that the torque current and the excitation current of the motor drive current are both greater than zero.

13. The control device according to claim 10, characterized in that, The control device is used to receive acceleration commands or heating commands, wherein: In response to the acceleration command, the motor controller is controlled to drive the drive motor to operate; In response to the heating command, the motor controller is controlled to drive the drive motor to heat the battery.

14. An electric vehicle, characterized in that, The electric vehicle includes a vehicle controller and a powertrain as described in any one of claims 1-6, a motor controller as described in any one of claims 7-9, or a control device as described in any one of claims 10-13.

15. The electric vehicle according to claim 14, characterized in that, The vehicle controller is used to send acceleration commands or heating commands to the motor controller or the control device.

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