WO2024120468A1

WO2024120468A1 - Powertrain, electric motor controller, control apparatus, and electric vehicle

Info

Publication number: WO2024120468A1
Application number: PCT/CN2023/136962
Authority: WO
Inventors: 李迎; 张宏济
Original assignee: 华为数字能源技术有限公司
Priority date: 2022-12-07
Filing date: 2023-12-07
Publication date: 2024-06-13
Also published as: CN115805848A

Abstract

Disclosed in the present application are a powertrain, an electric motor controller, a control apparatus for the electric motor controller, and an electric vehicle. The powertrain is configured to heat a traction battery of the electric vehicle. Operating modes of the powertrain comprise a battery internal resistor heating mode and a driving electric motor heating mode. The powertrain can choose, according to different conditions, to operate in different operating modes and can adjust heating power in each operating mode. The electric motor controller can output a high-frequency pulse current or electric motor exciting current to heat the traction battery, and according to the different conditions, the electric motor controller can choose to output the high-frequency pulse current or the electric motor exciting current. By means of controlling the on/off of each switch transistor of three bridge arms of the electric motor controller, the control apparatus for the electric motor controller controls the electric motor controller to output the pulse current or the electric motor exciting current. The powertrain, the electric motor controller, the control apparatus for the electric motor controller, and the electric vehicle disclosed in the present application can improve the heating efficiency for the traction battery and the energy utilization efficiency of the electric vehicle.

Description

Powertrain, motor controller, control device, electric vehicle

Technical Field

The present application relates to the field of thermal management of power batteries, and in particular to an electric vehicle powertrain, a motor controller, a control device for a motor controller, and an electric vehicle.

Background technique

At present, the main methods for heating power batteries include positive temperature coefficient resistor (PTC) heating, motor excitation current heating, high-frequency pulse current heating, etc. Positive temperature coefficient resistor heating requires additional electronic devices, so it has problems such as device redundancy and complex structure. Motor excitation current heating has problems such as too long heat transfer path and low heating efficiency. High-frequency pulse current heating has problems such as large motor vibration noise. Therefore, using only a single heating method to heat the power battery has problems such as low heating efficiency and low energy utilization of electric vehicles.

Summary of the invention

The present application provides a powertrain, a motor controller, and an electric vehicle, which are beneficial to improving the heating efficiency of the electric vehicle power battery and the energy utilization efficiency of the electric vehicle.

In a first aspect, an embodiment of the present application provides a powertrain. The powertrain includes a drive motor and a motor controller. The motor controller is used to receive power from a power battery and output a high-frequency pulse current or a motor excitation current to the drive motor. The drive motor is used to heat the power battery through a heat conduction device. The operation modes of the powertrain include 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 so that the powertrain operates in a battery internal resistance heating mode. The motor controller outputs a motor excitation current to the drive motor so that the powertrain operates in a drive motor heating mode. The powertrain is used to select operation in a battery internal resistance heating mode or a drive motor heating mode according to 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.

In an embodiment of the present application, the powertrain has two operating modes: battery internal resistance heating and drive motor heating. The powertrain can choose to operate in different modes to heat the power battery, thereby heating the power battery in different ways in different scenarios to avoid the shortcomings of each heating method. Therefore, the powertrain provided in the present application example can combine the advantages of different power battery heating methods to improve the battery heating efficiency. In an implementation of the first aspect, the powertrain operates in a battery internal resistance heating mode in response to a temperature parameter being less than a preset temperature threshold. The powertrain operates in a drive motor heating mode in response to a temperature parameter being greater than a preset temperature threshold.

In an implementation of the first aspect, in response to the duration of the powertrain operating in the battery internal resistance heating mode exceeding a preset duration, the operation mode of the powertrain is switched from the battery internal resistance heating mode to the drive motor heating mode.

In this implementation, the powertrain can choose to operate in different heating modes according to at least one of the drive motor temperature, the power battery temperature, the heat conduction device temperature, or the duration of the powertrain operating in the battery internal resistance heating mode. When the temperature is low, the powertrain operates in the battery internal resistance heating mode with a higher heating power to increase the battery heating rate. When the temperature is high, the powertrain operates in the drive motor heating mode with a lower heating power to save energy and prevent the battery from overheating. Therefore, this implementation can improve the energy utilization efficiency of electric vehicles and protect batteries.

In an implementation of the first aspect, the powertrain reduces the heating power when operating in the battery internal resistance heating mode in response to a temperature parameter rising when operating in the battery internal resistance heating mode. The powertrain reduces the heating power when operating in the drive motor heating mode in response to a temperature parameter rising when operating in the drive motor heating mode.

In an 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 length of time the powertrain operates in the battery internal resistance heating mode or the drive motor heating mode.

In an implementation of the first aspect, the heating power when the powertrain operates in the battery internal resistance heating mode is greater than the heating power when the powertrain operates in the drive motor heating mode.

In this implementation, during the process of the powertrain heating the power battery, the battery temperature continues to increase with the increase of temperature parameters and the increase of heating time. The heating power of the powertrain during the process of heating the power battery is reduced as the temperature parameters increase or the heating time increases to avoid battery overheating, which can protect the power battery. At the same time, by reducing the heating power as the temperature parameters increase and the heating time increases, it can reduce energy consumption and improve energy utilization efficiency.

In an implementation of the first aspect, the heat conduction device includes a drive motor heat circuit, a power battery heat circuit and a heat exchanger, the drive motor heat circuit is used to absorb heat generated by the drive motor, the power battery heat circuit is used to heat the power battery, and the heat of the drive motor heat circuit is conducted to the power battery heat circuit through the heat exchanger.

In a second aspect, the present application provides a motor controller for a drive motor. The drive motor includes a three-phase winding, and the drive motor is used to heat the power battery through a heat conduction device. The motor controller includes a bridge arm circuit composed of three bridge arms connected in parallel, and each bridge arm has two ends. Used to connect the positive and negative poles of the power battery, and the midpoints of the three bridge arms are used to connect the three-phase windings of the drive motor respectively. The motor controller is used to respond to the temperature parameter being less than the preset temperature threshold, and the midpoint of the bridge arm of at least one bridge arm of the bridge arm circuit outputs a high-frequency pulse current to the one-phase winding of the drive motor connected thereto. In response to the temperature parameter being greater than the preset temperature threshold, the midpoints of the three bridge arms of the bridge arm circuit output three-phase cross currents to the three-phase windings of the drive motor, and the three-phase cross currents make 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.

In an implementation of the second aspect, the motor controller reduces the frequency of the high-frequency pulse current in response to the duration of the motor controller outputting the high-frequency pulse current. The motor controller reduces one of the frequency or amplitude of the high-frequency pulse current or reduces the amplitude of the excitation current in response to the increase in the temperature parameter. The motor controller reduces the amplitude of the excitation current in response to the duration of the motor controller operating in the excitation current mode.

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

In a third aspect, an embodiment of the present application provides a control device for a motor controller, the motor controller is used to receive power from a power battery and drive the drive motor to operate or generate heat, the motor controller includes a bridge arm circuit composed of three bridge arms connected in parallel, each bridge arm includes an upper bridge arm switch tube and a lower bridge arm switch tube connected in series, the two ends of each bridge arm are respectively used to connect the positive and negative poles of the power battery, and the midpoints of the three bridge arms are respectively used to connect 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 tube of at least one of the three bridge arms and the lower bridge arm switch tube of at least another bridge arm to be turned on and off at the same time. In response to a temperature parameter being greater than a preset temperature threshold, the control device controls the three bridge arms to form a three-phase full-bridge inverter circuit. Wherein, the temperature parameter is the temperature of at least one of the drive motor, the power battery, or the heat conduction device.

In one implementation of the third aspect, the control device reduces the frequency and duty cycle of simultaneous on and off of the upper bridge arm switch tube of at least one bridge arm and the lower bridge arm switch tube of at least another bridge arm in response to the duration of the output of the motor excitation current by the three bridge arms of the bridge arm circuit. The control device reduces the amplitude of the three-phase alternating current output by the three bridge arms of the bridge arm circuit in response to the duration of the output of the motor excitation current by the three bridge arms of the bridge arm circuit. The control device reduces the frequency or duty cycle of the alternating switching of the upper bridge arm switch tube and the lower bridge arm switch tube of any bridge arm or reduces the amplitude of the three-phase alternating current output by the three bridge arms of the bridge arm circuit in response to the rise of the temperature parameter.

In an implementation of the third aspect, the control device is used to control the three bridge arms of the bridge arm circuit to output three-phase current to drive the drive motor to operate. The control device is used to control the three bridge arms of the motor controller bridge arm circuit to output three-phase alternating current as the drive motor drive current, and the control device controls the on and off of the six switch tubes of the three bridge arms of the motor controller so that the direct-axis current and the quadrature-axis current of the drive motor drive current are both greater than zero.

In an implementation of the third aspect, the control device is used to receive an acceleration instruction or a heating instruction. In response to the acceleration instruction, the control device controls the motor controller to drive the drive motor to operate. In response to the heating instruction, the control device controls the motor controller to drive the drive motor to heat the battery.

In a fourth aspect, an embodiment of the present application provides an electric vehicle, which includes a powertrain as in the first aspect, a motor controller as in the second aspect, or a motor controller control device as in the third aspect.

In one implementation of the fourth aspect, the vehicle controller is used to send an acceleration instruction or a heating instruction to the motor controller or the control device.

For the technical effects that can be achieved by any possible design in the second aspect, please refer to the description of the technical effects that can be achieved by any possible design in the first aspect. For the technical effects that can be achieved by any possible design in the third aspect, please refer to the description of the technical effects that can be achieved by any possible design in the first and second aspects. For the technical effects that can be achieved by any possible design in the fourth aspect, please refer to the description of the technical effects that can be achieved by any possible design in the first, second and third aspects, and no further details will be given here.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of an electric vehicle provided in an embodiment of the present application;

FIG2 is a schematic diagram of a heat conduction device provided in an embodiment of the present application;

FIG3 is a schematic diagram of an electric vehicle powertrain according to an embodiment of the present application;

FIG4 is a schematic diagram of a motor controller provided in an embodiment of the present application;

FIG5 is a schematic diagram of a control device for a motor controller provided in an embodiment of the present application;

FIG6 is a schematic diagram of a powertrain operation according to an embodiment of the present application;

FIG7 is a schematic diagram of a powertrain operation according to an embodiment of the present application;

FIG8 is a schematic diagram of the operation of a control device provided in an embodiment of the present application;

Detailed ways

In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, All other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of this application. The terms used in the embodiments of this application are only for the purpose of describing specific embodiments, and are not intended to limit this application. The singular forms of "a", "said" and "the" used in the embodiments of this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

It should be understood that the term "and/or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character "/" in this article generally indicates that the associated objects before and after are in an "or" relationship.

Electric vehicles use power batteries to provide electricity to drive the vehicle. Temperature has a great impact on power batteries. When charging and discharging power batteries at low temperatures, lithium deposition will occur, causing power battery capacity decay and even potential safety hazards. Therefore, the power battery needs to be heated to a certain temperature before the vehicle is allowed to drive.

Electric vehicles mainly use three methods to heat the power battery, including:

One way to heat a power battery is to use an external heating system to heat the power battery. For example, a power battery thermal circuit is provided outside the power battery, and a heat-carrying fluid that carries heat is provided in the power battery thermal circuit. A positive temperature coefficient resistor (PTC) heats the heat-carrying fluid in the power battery thermal circuit, and the heat-carrying fluid in the power battery thermal circuit conducts heat to the power battery to heat the power battery. Since the above method requires heating the heat-carrying fluid in the power battery thermal circuit first, and then heating the power battery through the heat-carrying fluid in the power battery thermal circuit, the heat transfer path is long and the heating efficiency is low.

One way to heat a power battery is to use the motor excitation current to generate heat on the drive motor to heat the power battery. The motor controller outputs three-phase alternating current to the drive motor, and the three-phase alternating current makes the torque of the drive motor zero but the excitation current non-zero. The excitation current generates heat on the drive motor windings, and the heat generated on the drive motor is transferred to the power battery for heating through a heat conduction device between the drive motor and the power battery. In the above method, since the heat of the drive motor needs to be transferred to the power battery through a heat conduction device, the above heating method has the disadvantages of a long heat transfer path, a low power battery heating rate, and a low heating efficiency.

A method of heating a power battery uses a high-frequency pulse current generated by a motor controller to heat the power battery. The bridge arm circuit of the motor controller generates a high-frequency pulse current. When the high-frequency pulse current passes through the power battery, it generates heat on the internal resistance of the power battery and heats the power battery. The above heating method has the advantage of a fast heating rate, but when the high-frequency pulse current passes through the drive motor, the drive motor will make the noise and vibration larger. Based on this, the embodiment of the present application provides an electric vehicle powertrain, a motor controller, and a control device for the motor controller. The powertrain uses different heating methods in combination according to temperature threshold conditions or time threshold conditions to heat the power battery, thereby avoiding the shortcomings of different power battery heating methods and improving the heating efficiency and energy utilization efficiency of the power battery. The following is a specific description of the electric vehicle powertrain, motor controller, and control device in conjunction with specific embodiments.

FIG1 is a schematic diagram of an electric vehicle provided in an embodiment of the present application. As shown in FIG1 , the electric vehicle includes a powertrain 20, a power battery 10, a heat conduction 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 respond to an acceleration instruction or a heating instruction of the vehicle controller 24 to operate the drive motor 23 or to generate heat for the drive motor 23. The heat generated by the drive motor 23 is conducted to the power battery 10 through the heat conduction device 21 to heat the power battery 10.

FIG2 is a schematic diagram of the structure of a heat conduction device of an electric vehicle provided in an embodiment of the present application. As shown in FIG2 , the heat conduction device 21 is located between the drive motor 23 and the power battery 10, and the heat conduction device 21 is used for heat exchange between the drive motor 23 and the power battery 10. The heat conduction device 21 includes a drive motor heat circuit 216, a power battery heat circuit 217 and a heat exchanger 213. The drive motor heat circuit 216 is used to absorb the heat generated by the drive motor 23, and the power battery heat circuit 217 is used to heat the power battery 10. The heat of the drive motor heat circuit 216 is transferred to the power battery heat circuit 217 through the heat exchanger 213. The drive motor heat circuit 216 includes a pump 211 and a pipeline 214. The power battery heat circuit 217 includes a pump 212 and a pipeline 215.

Exemplarily, the drive motor thermal circuit 216 is used to transfer the heat generated by 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 transfer the heat of the heat carrier fluid of the power battery thermal circuit 217 to the power battery. The pump 211 is used to adjust the flow rate and pressure of the heat carrier fluid of the drive motor thermal circuit 216, and the pump 212 is used to adjust the flow rate and pressure of the heat carrier fluid of the power battery thermal circuit 217. The heat exchanger 213 is used to exchange the heat of the drive motor thermal circuit 216 and the power battery circuit 217.

The heat generated by the drive motor 23 of the power assembly 20 provided in the embodiment of the present application can be transmitted to the power battery 10 through the heat conduction device 21, so that the heat generated by the drive motor 23 is used to heat the power battery 10, which can avoid the problem of excessive temperature of the drive motor 23 during the operation of the power assembly 20 and can also make full use of the heat generated by the drive motor 23 to heat the power battery 10.

In one embodiment, the heat carrier fluid of the drive motor thermal circuit 216 is a coolant. In one embodiment, the heat carrier fluid of the drive motor thermal circuit 216 is lubricating oil, and the heat exchanger 213 is an oil cooler.

FIG3 is a schematic diagram of a powertrain provided in an embodiment of the present application. As shown in FIG3 , the powertrain 20 includes a drive motor 23 and a motor control The motor controller 22 is used to receive power from the power battery 10 and output a high-frequency pulse current or a motor excitation current for heating the power battery 10 to the drive motor 23. The drive motor 23 is used to heat the power battery 10 through the heat conduction device 21.

In the embodiment of the present application, the operation modes of the powertrain 20 include a battery internal resistance heating mode and a drive motor heating mode. The powertrain 20 selects to operate in the battery internal resistance heating mode or the drive motor heating mode according to the temperature of at least one of the drive motor 23, the power battery 10, or the heat conduction device 21. When the powertrain 20 operates in the battery internal resistance heating mode, the motor controller 22 outputs a high-frequency pulse current to the drive motor 23. When the powertrain 20 operates in the drive motor heating mode, the motor controller 22 outputs a motor excitation current to the drive motor 23.

In the embodiment of the present application, the powertrain 20 operates in a 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, and 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.

In the embodiment of the present application, the power assembly 20 operates in the drive motor heating mode, the motor controller 22 receives power from the power battery 10 and outputs a motor excitation current to the drive motor 23, the motor excitation current generates heat on the drive motor winding, and the heat generated on the drive motor 23 winding is transferred to the power battery 10 through the heat conduction device 21.

In the embodiment of the present application, the heating power of the powertrain 20 when operating in the battery internal resistance heating mode is greater than the heating power of the powertrain 20 when 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 from the inside of the power battery 10, and the heat transfer path is shorter, thereby making the heating efficiency of the power battery 10 higher. In addition, the effective value of the high-frequency pulse current is greater than the motor excitation current, so the heating power is higher when the powertrain 20 operates in the battery internal resistance heating mode, and the heating rate of the power battery 10 is faster. The powertrain 20 provided in the embodiment of the present application can not only use the motor excitation current to generate heat on the winding of the drive motor 23 to heat the power battery 10, but also use the high-frequency pulse current to heat the power battery 10 from the inside of the power battery 10, thereby improving the battery heating efficiency and the energy utilization efficiency of the electric vehicle.

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

As shown in FIG4 , the motor controller 22 includes a bridge arm circuit 221 composed of three bridge arms connected in parallel. The two ends of each bridge arm of the bridge arm circuit 221 are respectively connected to the positive and negative electrodes of the power battery 10. The two ends of each bridge arm of the bridge arm circuit 221 are respectively connected to the two ends of the bus capacitor C1. The three bridge arm midpoints of the three bridge arms are respectively connected to the three windings L1, L2, and L3 of the drive motor 23.

As shown in FIG4 , 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.

In the embodiments of the present application, the switch tube can be one or more of various types of switch tubes such as a metal oxide semiconductor field effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), etc., which are not listed one by one in the embodiments of the present application.

In the embodiment of the present application, the switch tube includes a first electrode, a second electrode and a control electrode. The control electrode of the switch tube is used to control the on or off of the switch tube. When the switch tube is on, current can be transmitted between the first electrode and the second electrode of the switch tube. When the switch tube is off, current cannot be transmitted between the first electrode and the second electrode of the switch tube.

In the embodiment of the present application, the bridge arm circuit 221 outputs a high-frequency pulse current or a motor excitation current for heating the power battery 10. In one embodiment, the bridge arm circuit 221 outputs a high-frequency pulse current, and the high-frequency pulse current generates a large amount of heat on the internal resistance of the power battery 10. In one embodiment, the motor controller 22 outputs a motor excitation current, and the midpoints of the three bridge arms of the bridge arm circuit 221 output three-phase alternating current so that the drive motor 23 does not output torque and the motor excitation current is not 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.

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

In the embodiment of the present application, 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.

In the embodiment of the present application, the control device 222 controls the bridge arm circuit 221 of the motor controller 22 to output three-phase alternating current by outputting a 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.

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, the power assembly 20 operates in a battery internal resistance heating mode, and the high-frequency pulse current generates heat on the internal resistance of the power battery 10.

In one embodiment, the control device 222 sends a motor excitation current signal, and the bridge arm circuit 221 outputs three-phase alternating current. The three-phase alternating current 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.

The operation process of the powertrain, motor controller, and control device provided in the embodiments of the present application is further explained below.

In the embodiment of the present application, the power assembly 20 is used to select to operate in the battery internal resistance heating mode or the drive motor heating mode according to the temperature parameter. The temperature parameter is at least one of the power battery temperature, the drive motor temperature, and the heat conduction device temperature.

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 transfer device temperature is the heat carrier fluid temperature of the drive motor thermal circuit. In one embodiment, the heat transfer device temperature is the heat carrier fluid temperature of the power battery thermal circuit.

In the embodiment of the present application, the powertrain 20 operates in the battery internal resistance heating mode in response to the temperature parameter being less than the preset temperature threshold, and the powertrain 20 operates in the drive motor heating mode in response to the temperature parameter being greater than the preset temperature threshold.

In one embodiment, the preset temperature threshold is a preset power battery temperature threshold. Exemplarily, the preset power battery temperature threshold is minus 20 degrees Celsius. The powertrain 20 responds to the power battery temperature being less than minus 20 degrees Celsius, indicating that the power battery 10 temperature is too low. Too low a temperature of the power battery 10 will cause the capacity of the power battery 10 to decay seriously, and the charging power of the power battery 10 will be low or even unable to charge. In response to the power battery temperature being less than the preset temperature threshold, the powertrain 20 operates in a battery internal resistance heating mode with a higher heating power, so that the temperature of the power battery 10 rises faster to protect the power battery 10 and increase the charging power of the power battery 10.

When the power battery temperature is greater than minus 20 degrees Celsius, the power battery 10 capacity decay is relatively small, and the power battery 10 can be charged normally. Accordingly, in response to the power battery temperature being greater than minus 20 degrees Celsius, the power assembly 20 operates in a drive motor heating mode with a smaller heating power to prevent the power battery 10 from heating up too quickly.

In the embodiment of the present application, the powertrain 20 is used to switch the powertrain operation to a battery heating mode or a battery internal resistance heating mode according to temperature parameters.

In one embodiment, the power assembly 20 operates in the battery internal resistance heating mode. As the power battery temperature increases, the power battery temperature is greater than the preset power battery temperature threshold. At this time, the power battery temperature has risen to a higher value. In order to prevent the power battery 10 from overheating, the power assembly 20 operating mode is switched from the battery internal resistance heating mode with a larger heating power to the drive motor heating mode with a smaller heating power.

In one embodiment, the powertrain 20 operates in a battery internal resistance heating mode, and a high-frequency pulse current generates heat on the drive motor 23 so that the drive motor temperature is greater than a preset drive motor temperature threshold. The operation mode of the powertrain 20 is switched from the battery internal resistance heating mode to the drive motor heating mode to prevent the drive motor 23 from overheating.

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

In one embodiment, the powertrain 20 operates in the battery internal resistance heating mode, and the heat generated by the power battery 10 and the drive motor 23 is transferred to the heat transfer device 10, so that the temperature of the heat carrier fluid of the drive motor heat circuit 216 and the temperature of the heat carrier fluid of the power battery heat circuit 217 of the heat transfer device 21 increase. Therefore, the higher the temperature of the heat carrier fluid of the drive motor heat circuit 216 or the heat carrier fluid of the power battery heat circuit, the higher the temperature of the drive motor 23 or the power battery 10. The temperature of the heat carrier fluid of the drive motor heat circuit 216 or the temperature of the heat carrier fluid of the power battery heat circuit exceeds the preset value, and the drive motor 23 or the power battery 10 is at risk of overheating, and the operation mode of the powertrain 20 is switched from the battery internal resistance heating mode with a larger heating power to the drive motor heating mode with a smaller heating power.

In the embodiment of the present application, in response to the duration of the powertrain 20 operating in the battery internal resistance heating mode exceeding 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.

In one embodiment, as the duration of the powertrain 20 operating in the battery internal resistance heating mode exceeds a preset duration, the temperature of the power battery 10 rises, and there is a risk of overheating of the power battery 10. Therefore, the operation mode of the powertrain 20 is switched from the battery internal resistance heating mode with a higher heating power to the drive motor heating mode with a lower heating power to avoid battery overheating.

Exemplarily, the preset duration for the powertrain 20 to run in the battery internal resistance heating mode is 20 minutes. In response to the powertrain 20 running in the battery internal resistance heating mode for more than 20 minutes, the powertrain 20 operating mode switches from the battery internal resistance heating mode to the drive motor heating mode.

In the embodiment of the present application, the powertrain 20 reduces the heating power when operating in the battery internal resistance heating mode in response to the temperature parameter rising when the powertrain 20 operates in the battery internal resistance heating mode. The powertrain reduces the heating power when operating in the drive motor 23 heating mode in response to the temperature parameter rising when the powertrain 20 operates in the drive motor heating mode.

When the power assembly 20 heats the power battery 10, the temperature of the drive motor, the power battery, and the temperature of the heat transfer device will all increase. If the temperature of the power battery or the drive motor increases 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 power assembly 20 operates in the battery internal resistance heating mode or the drive motor heating mode, the power assembly 20 adjusts the heating power to decrease as the temperature parameter increases.

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

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

In the embodiment of the present application, the heating power of the power assembly 20 decreases as the temperature parameter increases, and the power assembly 20 is used to adjust the functional relationship between the heating power and the temperature parameter.

As shown in FIG. 6 , in one embodiment, the heating power of the powertrain 20 decreases linearly with the increase of the temperature parameter or the increase of the time that the powertrain 20 operates in the battery internal resistance heating mode or the drive motor heating mode.

As shown in FIG. 7 , in one embodiment, the heating power of the powertrain 20 decreases step by step as the temperature parameter increases or the duration that the powertrain 20 operates in the battery internal resistance heating mode or the drive motor heating mode increases.

In an embodiment of the present application, the time that the powertrain 20 operates in the battery internal resistance heating mode or the drive motor 23 heating mode increases, and the powertrain 20 is used to reduce the heating power when the powertrain 20 operates in the battery internal resistance heating mode or the drive motor 23 heating mode.

In the embodiment of the present application, as the time that the powertrain 20 runs in the battery internal resistance heating mode or the drive motor heating mode increases, the drive motor temperature and the power battery temperature continue to rise, and the drive motor 23 and the power battery 10 are at risk of overheating. In order to protect the drive motor 23 and the power battery, the powertrain 20 reduces the heating power when the powertrain 20 runs in the battery internal resistance heating mode or the drive motor 23 heating mode.

In one embodiment, the powertrain 20 reduces the heating power in response to an increase in the time that the powertrain 20 operates in the battery internal resistance heating mode. In one embodiment, the powertrain 20 reduces the heating power in response to an increase in the time that the powertrain 20 operates in the drive motor heating mode.

In the embodiment of the present application, the motor controller 22 outputs a high-frequency pulse current or a motor excitation current through the bridge arm circuit 221 to heat the power battery 10. Specifically, the midpoint of the bridge arm of at least one bridge arm of the bridge arm circuit 221 outputs a high-frequency pulse current to a single-phase winding of the drive motor 23 connected thereto, and the high-frequency pulse current generates heat on the internal resistance of the power battery 10 to heat the power battery 10. The midpoint of the bridge arm of the bridge arm circuit 221 outputs a three-phase alternating current to the three-phase winding of the drive motor 23, and the three-phase alternating 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.

In an embodiment of the present application, in response to a temperature parameter being less than a preset temperature threshold, the motor controller 22 outputs a high-frequency pulse current to a single-phase winding of a drive motor 23 connected thereto at the midpoint of at least one bridge arm of the motor controller 22. In response to a temperature parameter being greater than a preset temperature threshold, the motor controller 22 outputs a three-phase cross current to the three-phase winding of the drive motor 23 at the midpoints of the three bridge arms of the bridge arm circuit 221, and the three-phase cross current makes the torque of the drive motor 23 zero and the motor excitation current 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 conduction 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 conduction device temperature threshold.

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

In one embodiment, the bridge arm circuit 221 outputs a high-frequency pulse current, and the power battery temperature is greater than a preset power battery temperature threshold. At this time, the power battery temperature has risen to a higher value. In order 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.

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

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

In one embodiment, the bridge arm circuit 221 outputs a high-frequency pulse current, and when the temperature of the heat conduction device is greater than a 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.

In the embodiment of the present application, the duration of the bridge arm circuit 221 outputting the high-frequency pulse current exceeds the preset duration, and the bridge arm circuit 221 switches from outputting the high-frequency pulse current to outputting the motor excitation current.

In the embodiment of the present application, the motor controller 22 reduces the frequency and amplitude of the high-frequency pulse current or reduces the effective value of the motor excitation current in response to the increase in temperature parameters. In the process of the motor controller 22 outputting high-frequency pulse current or motor excitation current to heat the power battery 10, the temperature of the drive motor and the power battery rise rapidly, and the drive motor 23 and the power battery 10 are at risk of overheating. In order to protect the drive motor 23 and the power battery 10, the motor controller 22 reduces the frequency and amplitude of the high-frequency pulse current to reduce the high-frequency pulse current on the internal resistance of the power battery 10. The motor controller 22 reduces the effective value of the motor excitation current or reduces the heating power of the motor excitation current on the motor winding.

In one embodiment, the motor controller 22 responds to the temperature parameter rising when the bridge arm circuit 221 outputs the high-frequency pulse current, and 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 one embodiment, the motor controller 22 responds to the temperature parameter rising when the bridge arm circuit 221 outputs the motor excitation current, and 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 winding.

In the embodiment of the present application, the control device 222 is used to control the six switch tubes of the bridge arm circuit 221 to output high-frequency pulse current or motor excitation current. In one embodiment, the control device 222 is used to control the six switch tubes of the bridge arm circuit 221 to output high-frequency pulse current. The control device 222 determines the pulse frequency and duty cycle according to the current temperature of the power battery 10. The duty cycle refers to the discharge of the power battery 10, that is, the conduction time of the switches corresponding to the three bridge arms of the bridge arm circuit 221 during the process of current flowing from the positive electrode to the negative electrode of the power battery 10. In other words, when the power battery 10 is discharged, the upper bridge arm switch of at least one of the three bridge arms is turned on and the lower bridge arm switch of at least another bridge arm is turned on at the same time. The duty cycle refers to the ratio of the time when the upper bridge arm switch of at least one of the three bridge arms is turned on and the lower bridge arm switch of at least another bridge arm is turned on at the same time and the time when it is turned off at the same time in one cycle. According to the pulse frequency and the duty cycle, the controller device 222 generates a high-frequency pulse current that the bridge arm circuit 221 outputs. 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 .

As shown in FIG8 , FIG8 is a schematic diagram of a PWM (Pulse width modulation) drive signal, a current of a single-phase stand-alone L1 driving a motor 23, and a charge and discharge current of a power battery 10 when a duty cycle is equal to 0.5.

In one embodiment, the control device 222 is used to control the six switch tubes of the bridge arm circuit 221 to output the motor excitation current. The controller device 222 determines the heating power according to the current temperature of the power battery 10. The control device 222 is used to control the midpoint of the three bridge arms of the motor controller 22 to output three-phase alternating current to the three-phase winding of the drive motor 23 according to the heating power. The three-phase alternating 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 winding 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 alternating current.

In the embodiment of the present application, the control device 222 controls the six switch tubes of the bridge arm circuit 221 to output high-frequency pulse current in response to the temperature parameter being less than the preset temperature threshold, and the control device 222 controls the six switch tubes of the bridge arm circuit 221 to output motor excitation current in response to the 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.

In one embodiment, in response to the temperature parameter rising when the bridge arm circuit 221 outputs the high-frequency pulse current, the control device 222 reduces the frequency and duty cycle of the upper bridge arm switch tube of at least one bridge arm and the lower bridge arm switch tube of at least another bridge arm of the three bridge arms of the motor controller 22 at the same time, thereby reducing the heat generation power of the high-frequency pulse current on the internal resistance of the battery. The control device 222 controls the motor controller 22 to output the high-frequency pulse current, and the high-frequency pulse current causes the temperature of the power battery to rise rapidly, and the power battery 10 is at risk of overheating. In order to protect the power battery 10, the control device 222 reduces the frequency and duty cycle of the alternating switching of at least one upper bridge arm switch tube and at least one lower bridge arm switch tube 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 and thereby reduce the heating rate of the power battery.

In one embodiment, in response to the 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 upper bridge arm switch tube of at least one bridge arm and the lower bridge arm switch tube of at least another bridge arm in the bridge arm circuit 221 being turned on and off at the same time, thereby reducing the heat generation power of the high-frequency pulse current on the internal resistance of the battery. 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 continues to rise, and the power battery 10 is at risk of overheating. In order to protect the power battery 10, the control device 222 reduces the frequency and duty cycle of the upper bridge arm switch tube of at least one bridge arm and the lower bridge arm switch tube of at least another bridge arm in the bridge arm circuit 221 being turned on and off at the same time to reduce the heat generation power of the high-frequency pulse current on the internal resistance of the power battery 10 and thereby reduce the heating rate of the power battery.

In one embodiment, in response to the temperature parameter rising when the bridge arm circuit 221 outputs the motor excitation current, the control device 222 reduces the effective value of the three-phase alternating current outputted from the midpoints 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 temperature of the power battery to rise rapidly, and the power battery 10 is at risk of overheating. In order to protect the power battery 10, the control device 222 reduces the effective value of the three-phase alternating current, thereby reducing the effective value of the motor excitation current, and the heat generation power of the motor excitation current on the windings of the drive motor 23, thereby reducing the heating rate of the power battery.

In one embodiment, in response to the increase in the time duration that the control device 222 controls the motor controller 22 to output the motor excitation current, the control device 222 reduces the effective value of the three-phase AC output of the three bridge arms, thereby reducing the heat generation power of the motor excitation current on the winding of the drive motor 23. As the control device 222 controls the six switch tubes of the bridge arm circuit 221 to output the motor excitation current, the temperature of the power battery 10 continues to rise, and the power battery 10 is at risk of overheating. In order to protect the power battery 10, the control device 222 reduces the effective value of the three-phase AC The effective value thereby reduces the effective value of the motor excitation current, and the heat generation power of the motor excitation current on the winding of the drive motor 23 thereby reduces the heating rate of the power battery.

In the embodiment of the present application, the control device 222 is used to receive an acceleration instruction to operate the drive motor 23 or to receive a heating instruction 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 instruction. In one embodiment, the control device 222 controls the motor controller 22 to heat the battery in response to the heating instruction. Exemplarily, the vehicle controller 24 sends an acceleration instruction to the control device 222, and the control device 222 controls the motor controller 22 to output a three-phase alternating current with a torque current and an excitation current greater than zero to the drive motor 23, and the three-phase alternating current operates the drive motor 23 and thus the electric vehicle operates. Exemplarily, the vehicle controller 24 sends a heating instruction to the control device 222, and the control device 222 controls the motor controller 22 to output a high-frequency pulse current, and the powertrain 20 operates in the battery internal resistance heating mode to heat the power battery 10. Exemplarily, the vehicle controller 24 sends a heating instruction to the control device 222, and the control device 222 controls the motor controller 22 to output an excitation current, and the powertrain 20 operates in the drive motor heating mode to heat the power battery 10.

The above is only the preferred implementation mode of the present application, and is not any form of limitation on the present application. Although the present application has been disclosed as the preferred implementation mode as above, it is not used to limit the present application. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent implementation modes without departing from the scope of the technical solution of the present application. However, any simple modification, equivalent change and modification made to the above implementation modes based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

A powertrain, characterized in that the powertrain includes a drive motor and a motor controller, the motor controller is used to receive power from the power battery and output a high-frequency pulse current or a motor excitation current to the drive motor, the drive motor is used to heat the power battery through a heat conduction device, the operation mode of the powertrain includes a battery internal resistance heating mode and a drive motor heating mode, the powertrain is used to select the battery internal resistance heating mode or the drive motor heating mode according to a temperature parameter, wherein:

The powertrain operates in the battery internal resistance heating mode, and the motor controller outputs the high-frequency pulse current to the drive motor;

The power assembly operates in the drive motor heating mode, and the motor controller outputs the motor excitation current to the drive motor;

The temperature parameter is the temperature of at least one of the drive motor, the power battery or the heat conduction device.
The powertrain according to claim 1, wherein the powertrain is used for:

In response to the temperature parameter being less than a preset temperature threshold, the powertrain operates in the battery internal resistance heating mode;

In response to the temperature parameter being greater than the preset temperature threshold, the powertrain operates in the drive motor heating mode.
The power assembly according to any one of claims 1 to 2, wherein the power assembly is used for:

In response to a time period during which the powertrain operates in the battery internal resistance heating mode exceeding a preset time period, the operation mode of the powertrain is switched from the battery internal resistance heating mode to the drive motor heating mode.
The power assembly according to any one of claims 1 to 3, wherein the power assembly is used for:

In response to the temperature parameter rising when operating in the battery internal resistance heating mode, reducing the heating power when operating in the battery internal resistance heating mode; or

In response to the temperature parameter rising when operating in the drive motor heating mode, the heating power when operating in the drive motor heating mode is reduced.
The power assembly according to any one of claims 1 to 3, wherein the power assembly is used for:

In response to the length of time that the powertrain operates 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.
According to the powertrain according to any one of claims 1 to 5, 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.
According to the power assembly according to any one of claims 1 to 6, the heat conduction device includes a drive motor heat circuit, a power battery heat circuit and a heat exchanger, the drive motor heat circuit is used to absorb heat generated by the drive motor, the power battery heat circuit is used to heat the power battery, and the heat of the drive motor heat circuit is conducted to the power battery heat circuit through the heat exchanger.
A motor controller for a drive motor, characterized in that the drive motor includes a three-phase winding, the drive motor is used to heat a power battery through a heat conduction device, the motor controller includes a bridge arm circuit composed of three bridge arms connected in parallel, the two ends of each bridge arm are respectively used to connect the positive and negative electrodes of the power battery, and the midpoints of the three bridge arms are respectively used to connect the three-phase winding of the drive motor, and the motor controller is used to:

In response to the temperature parameter being less than a preset temperature threshold, the bridge arm circuit outputs a high-frequency pulse current to a phase winding of the drive motor to which it is connected;

In response to the temperature parameter being greater than the preset temperature threshold, the midpoint of the bridge arm of the bridge arm circuit outputs three-phase alternating current to the three-phase winding of the drive motor, and the three-phase alternating current makes the drive motor torque zero and the motor excitation current greater than zero;

Wherein, the temperature parameter is the temperature of at least one of the drive motor, the power battery or the heat conduction device.
According to the motor controller of claim 8, 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 the temperature parameter rising, reducing one of the frequency or the amplitude of the high-frequency pulse current or reducing the amplitude of the excitation current; or,

In response to the length of time that the motor controller outputs the motor excitation current, the amplitude of the motor excitation current is reduced.
According to the motor controller according to any one of claims 7-8, each of the bridge arms comprises an upper bridge arm switch tube and a lower bridge arm switch tube connected in series, one end of the upper bridge arm switch tube is used to connect the positive electrode of the power battery, the other end of the upper bridge arm switch tube is connected to one end of the lower bridge arm switch tube to form the midpoint of each bridge arm, and the other end of the lower bridge arm switch tube is used to connect the negative electrode of the power battery.
A control device for a motor controller, the motor controller is used to receive power from a power battery and drive the drive motor to operate or generate heat, the motor controller includes a bridge arm circuit composed of three bridge arms connected in parallel, each of the bridge arms includes an upper bridge arm switch tube and a lower bridge arm switch tube connected in series, the two ends of each bridge arm are respectively used to connect the positive and negative electrodes of the power battery, and the midpoints of the three bridge arms are respectively used to connect the three-phase windings of the drive motor, and the control device is used to:

In response to the temperature parameter being less than a preset temperature threshold, controlling an upper bridge arm switch tube of at least one bridge arm and a lower bridge arm switch tube of at least another bridge arm among the three bridge arms to be turned on and off simultaneously so that the motor controller outputs a high-frequency pulse current;

In response to the temperature parameter being greater than a preset temperature threshold, controlling the three bridge arms to form an inverter circuit so that the motor controller outputs a motor excitation current;

Wherein, the temperature parameter is the temperature of at least one of the drive motor, the power battery or the heat conduction device.
The control device according to claim 11, wherein the control device is used for:

In response to the duration of high-frequency pulse current outputted from the midpoints of the three bridge arms, the frequency and duty cycle of simultaneous on and off of the upper bridge arm switch tube of at least one bridge arm and the lower bridge arm switch tube of at least another bridge arm of the three bridge arms are reduced; or,

In response to the duration of the three bridge arms outputting the motor excitation current, reducing the three-phase AC effective value output by the three bridge arms; or

In response to the increase in the temperature parameter, the frequency or duty cycle of simultaneously turning on and off the upper bridge arm switch tube of at least one bridge arm and the lower bridge arm switch tube of at least another bridge arm among the three bridge arms is reduced, or the three-phase AC effective value output by the three bridge arms is reduced.
According to the control device of claim 12, the control device is used to control the three bridge arms to output three-phase current to drive the drive motor to operate, and the control device is used to:

The three bridge arms are controlled to output three-phase alternating current as a driving current for the driving motor, and the control device controls the on and off of the six switch tubes of the three bridge arms so that the torque current and the motor excitation current of the driving current of the driving motor are both greater than zero.
The control device according to claim 11, wherein the control device is used to receive an acceleration instruction or a heating instruction, wherein:

In response to the acceleration instruction, controlling the motor controller to drive the drive motor to operate;

In response to the heating instruction, the motor controller is controlled to drive the drive motor to heat the battery.
An electric vehicle, characterized in that the electric vehicle comprises a vehicle controller and a powertrain as described in any one of claims 1 to 7, a motor controller as described in any one of claims 8 to 10, or a control device as described in any one of claims 11 to 14.
According to the electric vehicle according to claim 15, the vehicle controller is used to send an acceleration instruction or a heating instruction to the motor controller or the control device.