Electric-motor controller, electric drive system, and vehicle

Abstract

An electric-motor controller (104), comprising an inverter circuit (120) and a control circuit (110), wherein the inverter circuit (120) comprises three switch tube bridge arms, two ends of each switch tube bridge arm being configured to receive power supplied from a traction battery (102), and the middle point of each switch tube bridge arm being configured to connect one of three phases of windings of an electric motor (130); in response to the absolute value of a torque demand indicated by a torque signal being greater than or equal to a preset torque value, the control circuit (110) controls the inverter circuit (120) to output a three-phase alternating current; and in response to the rotation speed of the electric motor (130) being less than a first rotation speed value or greater than a second rotation speed value and the absolute value of the torque demand indicated by the torque signal being less than the preset torque value, the control circuit (110) controls a plurality of switch tubes in the inverter circuit (120) to turn off. Further disclosed are an electric drive system and a vehicle (100). The electric-motor controller can achieve, without manual intervention, a torque output effect that meets a driver's driving intent, and can reduce the energy consumption of an electric motor, thus facilitating a reduction in the energy consumption of the whole vehicle, and prolonging the endurance of the whole vehicle.

Description

Motor controller, electric drive system and vehicle

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on August 28, 2023, with application number 202311091876.7, and priority to the Chinese patent application entitled "Motor Controller, Electric Drive System and Vehicle", all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of new energy vehicles, and more specifically, to a motor controller, a point drive system and a vehicle. Background Art

[0003] With the increasing popularity of new energy vehicles, the energy consumption of vehicle motors has become a significant factor limiting their range. In existing technologies, upon receiving a torque signal from a vehicle controller, the motor controller supplies power to the motor based on the torque demand indicated by the torque signal, thereby enabling the motor to generate torque that meets the torque demand.

[0004] However, driving situations are complex and varied, and there are situations where the torque demand determination by the vehicle controller (VCU) may not reflect the driver's actual torque demand intention. For example, when idling on a flat road, the VCU issues a torque signal because the gear is in D, but the driver does not need to drive the motor to generate torque, resulting in unnecessary energy consumption. Another example is when parking on a slope, the motor outputs positive torque to prevent rolling. However, due to the interaction between the wheel end and the hydraulic brake system, some of this positive torque is dissipated as heat, resulting in unnecessary energy consumption. For another example, the prior art provides a "weak energy recovery mode" in which the motor provides braking force. In this mode, the motor can convert the vehicle's kinetic energy into electrical energy, which is then converted back into kinetic energy when the vehicle is driven. However, in coasting conditions, the driver does not need a noticeable braking feel. If the motor is operated in this "weak energy recovery mode," the energy recovered through electric braking is limited, and the energy conversion efficiency is not 100%, resulting in unnecessary energy consumption.

[0005] Therefore, there is an urgent need for a technology that can reduce energy consumption.

[0006] Summary of the Invention

[0007] The present application provides a motor controller, an electric drive system and a vehicle, which can reduce energy consumption and improve vehicle endurance.

[0008] In a first aspect, the present application provides a motor controller comprising an inverter circuit and a control circuit. The inverter circuit comprises three switch tube bridge arms, each of which has two ends for receiving power from a power battery, and a midpoint for connecting to a three-phase winding of a motor. The control circuit is configured to control the inverter circuit to output three-phase alternating current in response to the absolute value of the torque demand indicated by a torque signal being greater than or equal to a preset torque value. The control circuit is configured to control the multiple switch tubes in the inverter circuit to turn off in response to the motor speed being less than a first speed value or greater than a second speed value, and the absolute value of the torque demand indicated by the torque signal being less than the preset torque value, the second speed being greater than the first speed.

[0009] By controlling whether the inverter circuit outputs AC power to the motor, and thus whether the motor outputs torque, based on the motor's speed and torque demand, the control of torque output can be aligned with the driver's actual control intent. For example, when the motor speed is low and the torque demand is low, it can be determined that the vehicle is currently idling and does not require the motor to provide positive torque. The switch in the inverter circuit can then be turned off, thereby reducing energy consumption. For another example, when the motor speed is high and the torque demand is low, it can be determined that the vehicle is currently coasting and does not require the motor to provide negative torque as a braking force. The switch in the inverter circuit can then be turned off, thereby reducing energy consumption.

[0010] In one implementation, the control circuit is configured to control the shutdown of multiple switches in the inverter circuit in response to the motor speed being less than the first speed value for a period greater than a first period, and the absolute value of the torque demand being less than the preset torque value for a period greater than a second period. By recording the motor speed and the duration during which the torque demand meets the preset conditions, the accuracy and reliability of idle state determination can be improved, thereby enhancing the practicality and safety of the solution provided herein.

[0011] In another implementation, the control circuit is specifically configured to control the plurality of switches in the inverter circuit to turn off in response to the motor speed being greater than the second speed value for a period greater than a third period, and the absolute value of the torque demand being less than the preset torque value for a period greater than a second period. By recording the motor speed and the duration during which the torque demand meets the preset conditions, the accuracy and reliability of the coasting state determination can be improved, thereby enhancing the practicality and safety of the solution provided herein.

[0012] In another implementation, the control circuit controls the inverter circuit to output three-phase AC power in response to the absolute value of the motor speed change within a preset time being greater than a preset speed change value. When the motor speed changes rapidly, it can be determined that the driver requires the motor to output torque. In this case, the switching transistor in the inverter circuit is controlled to output AC power to the motor, thereby promptly meeting the driver's needs and improving the practicality and safety of the solution provided by this application.

[0013] In another implementation, the control circuit is configured to control the inverter circuit to output three-phase AC power in response to the absolute value of the torque demand being greater than the preset torque value. When the absolute value of the torque demand is greater, it can be determined that the driver requires the motor to output torque. In this case, the control circuit controls the switching transistor in the inverter circuit to output AC power to the motor, thereby driving the motor to generate torque. This can promptly meet the driver's demand and improve the practicality and safety of the solution provided by this application.

[0014] One way to stop the inverter circuit from outputting AC power is to control the inverter circuit to shut down each switch in each switching arm to stop outputting AC power. Alternatively, the control circuit controls the inverter circuit to shut down the switches in some switching arms to stop outputting AC power. In other words, "controlling the inverter circuit to shut down multiple switches" can be understood as controlling all switches in the inverter circuit to shut down, or controlling some switches in the inverter circuit to shut down.

[0015] In one implementation, the control circuit is configured to receive a speed signal from the motor, wherein the information indicated by the speed signal includes the speed value of the motor. Thus, the control circuit can determine the speed of the motor based on the speed signal.

[0016] In one implementation, the torque demand can be calculated by a control circuit based on a signal such as a throttle signal or a brake signal. That is, the control circuit is configured to receive a throttle signal triggered by an accelerator pedal or a brake signal triggered by a brake pedal, and the throttle signal or the brake signal is used to determine the value of the torque demand. The direction of the torque demand indicated by the torque signal corresponding to the throttle signal is opposite to the direction of the torque demand indicated by the torque signal corresponding to the brake signal. Specifically, the direction of the torque demand indicated by the torque signal corresponding to the throttle signal is the same as the direction of vehicle travel, and the torque demand indicated by the torque signal corresponding to the throttle signal is used to instruct the vehicle to move forward. The direction of the torque demand indicated by the torque signal corresponding to the brake signal is opposite to the direction of vehicle travel, and the torque demand indicated by the torque signal corresponding to the brake signal is used to instruct the vehicle to brake.

[0017] In another implementation, the torque demand may be calculated by a vehicle controller or a vehicle electronic stability system based on a throttle signal or a brake signal.

[0018] In this case, the communication end of the control circuit is used to connect to the vehicle body electronic stability system, receive the torque signal sent by the vehicle body electronic stability system, and indicate the calculated value to the control circuit through the torque signal.

[0019] Alternatively, the communication end of the control circuit is used to connect to the vehicle controller and receive the torque signal sent by the vehicle controller.

[0020] In the present application, the executing entity that determines whether the inverter circuit outputs or stops outputting DC to the motor based on the motor speed and torque requirement can also be the vehicle controller, that is, the vehicle controller can determine the torque requirement based on the throttle signal or the brake signal, and determine whether the motor needs to output torque (or whether the inverter circuit needs to output AC power to the motor) based on the torque requirement and the motor speed, and send the determination result to the control circuit, that is, the control circuit is used to receive a control signal from the vehicle controller, and the control signal is used to indicate whether to turn on or off the switch tube in the inverter circuit.

[0021] In one implementation, the communication terminal of the control circuit is connected to a vehicle controller, and the control circuit is configured to receive a vehicle driving state signal transmitted by the vehicle controller. The vehicle driving state signal is used by the control circuit to obtain the torque signal. That is, while the above examples illustrate a method for determining the torque demand based on a brake signal or an accelerator signal, the present application is not limited thereto. For example, the torque demand may also be determined based on a vehicle driving state signal from the vehicle controller. The vehicle driving state signal may include one or more of the following signals: a gear position signal, a vehicle speed signal, a driving mode signal, an energy regenerative mode signal, etc.

[0022] In a second aspect, the present application provides an electric drive system comprising a motor and a motor controller. The motor controller includes a control circuit and an inverter circuit. The motor receives alternating current (AC) power from the inverter circuit. The inverter circuit includes three switching tube bridge arms, each of which has two ends for receiving power from a power battery and a midpoint for connecting to one of the three-phase windings of the motor. The control circuit controls the inverter circuit to output AC power in response to the absolute value of the torque demand indicated by a torque signal being greater than or equal to a preset torque value. The control circuit controls the inverter circuit to turn off multiple switching tubes in response to the motor's speed being less than a first speed value or greater than a second speed value, and the absolute value of the torque demand indicated by the torque signal being less than the preset torque value. The second speed is greater than the first speed.

[0023] In one implementation, the control circuit is further configured to control the shutdown of multiple switching tubes of the inverter circuit in response to the fact that the speed of the motor is less than the first speed value for a period greater than a first period and the absolute value of the torque demand indicated by the torque signal is less than the preset torque value for a period greater than a second period.

[0024] In another implementation, the control circuit is further used to control the shutdown of multiple switching tubes of the inverter circuit in response to the fact that the speed of the motor is greater than the second speed value for a period greater than a third period and the absolute value of the torque demand indicated by the torque signal is less than the preset torque value for a period greater than the second period.

[0025] In one implementation, in response to an absolute value of a change in the motor's speed within a preset time being greater than a preset speed change value, the control circuit is further configured to control the inverter circuit to output three-phase alternating current.

[0026] In one implementation, in response to the absolute value of the torque demand indicated by the torque signal being greater than the preset torque value, the control circuit is further configured to control the inverter circuit to output three-phase alternating current.

[0027] In the present application, the execution entity that determines whether the inverter circuit outputs or stops outputting DC to the motor based on the motor speed and torque requirements can be the control circuit in the motor controller, that is, the motor controller also includes a control circuit, which is used to control the opening and closing of the switching tube in the inverter circuit so that the inverter circuit outputs AC power or stops outputting AC power.

[0028] In this case, the control circuit is used to receive a speed signal from the motor, where the speed signal includes a speed value of the motor.

[0029] In one implementation, the torque demand can be calculated by the control circuit based on signals such as a throttle signal or a brake signal, that is, the control circuit is used to receive a throttle signal triggered by an accelerator pedal or a brake signal triggered by a brake pedal, and the throttle signal or the brake signal is used to determine the value of the torque demand.

[0030] In another implementation, the torque demand can be calculated by the vehicle controller based on a throttle signal or a brake signal, and the calculated value is indicated to the control circuit through a torque signal, that is, the control circuit is used to receive a torque signal from the vehicle controller, and the torque signal includes the value of the torque demand.

[0031] In the present application, the executing entity for determining whether to turn off the multiple switching tubes of the inverter circuit based on the motor speed and torque demand can also be the vehicle controller, that is, the vehicle controller can determine the torque demand based on the throttle signal or the brake signal, and determine whether the motor needs to output torque (or whether the inverter circuit needs to output AC power to the motor) based on the torque demand and the motor speed, and send the determination result to the control circuit, that is, the control circuit is used to receive a control signal from the vehicle controller, and the control signal is used to instruct to turn on or off the switching tube in the inverter circuit.

[0032] In a third aspect, a vehicle is provided, comprising a power battery and an electric drive system. The electric drive system includes a motor controller and a motor. The motor controller includes a controller and an inverter circuit. The motor is connected to the output of the inverter circuit, and the power battery is connected to the input of the inverter circuit. The inverter circuit includes three switching transistor bridge arms, each of which has two ends for receiving power from the power battery, and a midpoint for connecting to one of the three-phase windings of the motor. In response to the absolute value of the torque demand indicated by the torque signal being greater than or equal to a preset torque value, the control circuit controls the inverter circuit to output alternating current. In response to the motor speed being less than a first speed value or greater than a second speed value, and the absolute value of the torque demand being less than the preset torque value, the control circuit controls the multiple switching transistors of the inverter circuit to turn off. The second speed is greater than the first speed.

[0033] In the present application, the execution entity for determining whether to turn off the multiple switch tubes of the inverter circuit based on the motor speed and torque demand may be a control circuit in the motor controller.

[0034] In one implementation, the torque demand may be calculated by a control circuit based on a signal such as a throttle signal or a brake signal.

[0035] In another implementation, the torque demand may be obtained by calculation by a vehicle controller based on a throttle signal or a brake signal, and the calculated value may be indicated to a control circuit via a torque signal.

[0036] Alternatively, the executor of the multiple switching tubes that determine whether to shut down the inverter circuit based on the motor speed and torque requirement can also be the vehicle controller, that is, the vehicle controller can determine the torque requirement based on the throttle signal or the brake signal, and determine whether the motor needs to output torque based on the torque requirement and the motor speed, and send the determination result to the control circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG1 is a schematic diagram of a vehicle scene provided in an embodiment of the present application.

[0038] FIG2 is a schematic structural diagram of an electric drive system provided in an embodiment of the present application.

[0039] FIG3 is a schematic diagram of a connection structure of a motor controller provided in an embodiment of the present application.

[0040] FIG4 is a schematic structural diagram of an example of a vehicle provided in an embodiment of the present application.

[0041] FIG5 is a schematic diagram of a communication architecture of a vehicle provided in an embodiment of the present application.

[0042] FIG6 is a flow chart of an example of a method for controlling a motor provided in an embodiment of the present application.

[0043] FIG7 is a flow chart of another example of a method for controlling a motor provided in an embodiment of the present application.

[0044] FIG8 is a flow chart of another example of a method for controlling a motor provided in an embodiment of the present application.

[0045] FIG9 is a flow chart of another example of a method for controlling a motor provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] The following will describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings. Obviously, the embodiments described are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0047] With the popularity of new energy vehicles, the vehicle's electric energy consumption has become an important factor restricting the range of new energy vehicles. Usually, when a new energy vehicle is parked, the motor that provides driving force for the vehicle is always in an open-wave working state, continuously consuming electric energy. Among them, "open wave" can also be called "open tube" or "wave generation", which means driving the switch in the inverter circuit to close to output AC power to the motor. The opposite of "open wave" is "off wave". "Off wave" can also be called "off tube", "off wave" or "sealed wave", which means driving the switch in the inverter circuit to disconnect to stop outputting AC power to the motor.

[0048] For example, when the vehicle is idling, because the driver has stepped on the brake pedal, the vehicle control unit (VCU) has no driving torque demand for the motor. However, when the motor is in the open-wave working state, the power battery still needs to transmit power to the microcontroller unit (MCU), and continues to consume power.

[0049] For another example, when a vehicle is parked and idling on a slope, even if the driver steps on the brake pedal, the vehicle controller will still send a torque request to the microcontroller unit, causing the motor to generate positive torque to ensure that the vehicle has forward torque and does not slide backward after the driver releases the brake pedal. However, the positive torque generated by the motor interacts with the hydraulic braking system at the wheel end when the vehicle is parked and is dissipated as heat, which also causes a waste of electrical energy.

[0050] For another example, when a new energy vehicle is coasting at a certain speed, if the driver selects the vehicle's "weak energy recovery" mode, the vehicle controller will still send a torque request to the microcontroller, causing the motor to provide a small amount of generating torque for energy regeneration. However, when the vehicle is in the coasting state, the driver does not want the vehicle to have a noticeable braking feel, so the energy that can be recovered through electric braking is limited. In addition, the energy recovery process involves multiple energy conversions (for example, between kinetic energy and electrical energy), which also results in energy waste and loss.

[0051] Based on this, the present application proposes a motor controller, electric drive system, and vehicle. The motor controller provided in this application turns off or on the switching tubes in the inverter circuit according to the actual operating conditions of the vehicle to reduce the energy consumption of the inverter circuit, helping to reduce energy consumption, improve vehicle endurance, and control the switching tubes in the inverter circuit to turn off.

[0052] Figure 1 is a schematic diagram of a vehicle according to an embodiment of the present application. Referring to Figure 1 , vehicle 100 includes an electric drive system 101 and a power battery 102 connected to electric drive system 101. Power battery 102 provides electrical energy to electric drive system 101. Electric drive system 101 receives electrical energy from power battery 102 and provides kinetic energy to vehicle 100.

[0053] The structure of the electric drive system 101 can be shown in FIG2 , where the electric drive system 101 includes a motor controller 104 and a motor 130 . The motor 130 is connected to the wheels 190 of the vehicle 100 . The motor 130 is used to drive the wheels 190 during driving of the vehicle 100 .

[0054] FIG3 is a schematic diagram of the operation of the electric drive system 101. As shown in FIG3, the operation modes of the electric drive system 101 include a drive mode and an energy recovery mode. Specifically, when the electric drive system 101 is in the drive mode, the inverter circuit 120 receives power from the power battery 102 and converts the direct current from the power battery 102 into three-phase alternating current to drive the motor 130. When the electric drive system 101 is in the energy recovery mode, it means that when the vehicle 100 is in a braking state, the wheels 190 drive the motor 130 to rotate, and the drive motor 130 operates in a power generation state and outputs negative torque. The drive motor 130 converts the kinetic energy of the vehicle 100 into electrical energy. While generating electricity, the drive motor 130 can also provide feedback braking force for the vehicle 100.

[0055] FIG4 is a schematic diagram of the specific structure of the motor controller. As shown in FIG4 , the motor controller 104 includes a control circuit 110 and an inverter circuit 120. The inverter circuit 120 includes three switch tube bridge arms, each of which has two ends for receiving power from the power battery 102, and a midpoint for connecting one phase of the three-phase winding of the motor 130. The inverter circuit 120 is used to convert the direct current from the power battery 102 into three-phase alternating current and supply power to the motor 130 when the electric drive system 101 is in the driving mode, or the inverter circuit 120 is used to convert the alternating current from the motor 130 into direct current and charge the power battery 102 when the electric drive system 101 is in the energy recovery mode. The control circuit 110 is used to send a control signal to the inverter circuit 120 to control the operation of the inverter circuit 120.

[0056] FIG5 is a schematic diagram of the communication architecture of vehicle 100. As shown in FIG5 , the communication terminal of control circuit 110 is connected to a communication bus. Control circuit 110 can then establish communication with other components of vehicle 100 (e.g., accelerator pedal 170, brake pedal 180, electronic stability control system 150, vehicle brake feedback system 160, vehicle controller 140, etc.) via the communication bus. This means that control circuit 110 can directly obtain signals from the communication bus, such as vehicle driving status signals, torque demand signals, gear position signals, driving mode, energy feedback mode, throttle signals, brake signals, etc. Control circuit 110 can also upload signals to the communication bus, such as the actual torque signal of motor 130 and the current of inverter circuit 120.

[0057] For example, the communication bus may be a controller area network (CAN) bus or a FlexRay bus. When the communication bus is a CAN bus, it may be specifically implemented as a chassis CAN bus of the vehicle 100 .

[0058] The specific implementation of the control circuit 110 can be a central processing unit (CPU), other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0059] The input end of the control circuit 110 is connected to a speed detection device, which is provided on the rotating shaft of the motor 130. At this time, the control circuit 110 can receive a speed signal or a resolver signal of the motor 130 from the speed detection device. Exemplarily, the speed detection device can be a resolver sensor or a speed sensor. In addition, the output end of the control circuit 110 is connected to the control end of the inverter circuit 120. The control circuit 110 provided in the embodiment of the present application is used to receive a torque signal and control the inverter circuit 120 to drive the motor 130 to generate a torque value indicated by the torque signal. The torque signal is used to indicate the torque requirement of the vehicle 100.

[0060] In one embodiment, the communication terminal of the control circuit is used to connect to the vehicle electronic stability system 140, and the vehicle controller 140 sends a torque signal to the control circuit 110. The vehicle controller 140 determines the vehicle torque requirement based on the operating state of the vehicle 100 and sends the torque signal to the control circuit 110.

[0061] In one embodiment, the communication terminal of the control circuit 110 is used to connect to the vehicle body electronic stability system 150 and receive the torque signal sent by the vehicle body electronic stability system 150 .

[0062] In one embodiment, the control circuit 110 is configured to receive a throttle signal generated by triggering an accelerator pedal. The throttle signal is configured to generate a torque signal. The torque demand indicated by the torque signal corresponding to the throttle signal is a positive torque.

[0063] In one embodiment, the control circuit 110 is configured to receive a brake signal generated by a brake pedal trigger, and the brake signal is configured to generate a torque signal. The torque demand indicated by the torque signal corresponding to the brake signal is negative torque. Specifically, in response to the torque signal corresponding to the brake signal, the control circuit 110 controls the motor 130 to operate in an energy recovery state. The motor 130 is configured to generate alternating current. During this process, the torque corresponding to the motor 130 is negative torque, and the motor 130 provides regenerative braking force for the vehicle 100.

[0064] In one embodiment, the control circuit 110 can determine whether it is possible to control the shutdown of multiple switches in the inverter circuit 120 based on the speed and torque signal of the motor 130. Specifically, the control circuit 110 determines whether the speed and torque signal of the motor 130 meet a first preset condition. If the first preset condition is met, the control circuit 110 determines that it is possible to control the shutdown of multiple switches in the inverter circuit 120. The first preset condition can be that the speed of the motor 130 is less than a first speed value or greater than a second speed value, and the absolute value of the torque demand indicated by the torque signal is less than a preset torque value. The second speed is greater than the first speed.

[0065] In one embodiment, the control circuit 110 can control the current output by the inverter circuit 120 to the motor 130, thereby controlling the speed or torque of the motor 130. For example, if the control circuit 110 determines that the speed and torque signals of the motor 130 do not meet a first preset condition, the control circuit 110 can control the amount of AC power output by the inverter circuit 120 to the motor 130 based on the received torque signal, thereby controlling the output torque of the motor 130. The torque signal can be determined by the control circuit 110 based on other signals, such as a throttle signal and a brake signal. The throttle signal is generated in response to the driver pressing the accelerator pedal, and the brake signal is generated in response to the driver pressing the brake pedal. In this case, the control circuit 110 receives the corresponding throttle signal or brake signal from the accelerator pedal or brake pedal. The torque signal is obtained by the control circuit 110 from the torque calculation module, which calculates the torque signal based on the throttle signal, brake signal, or vehicle driving status signal. The torque calculation module includes, but is not limited to, a vehicle controller and an electronic stability control system.

[0066] It is understandable that the control circuit 110 can also receive a throttle signal or a brake signal from the torque calculation module. The torque calculation module includes but is not limited to components such as the vehicle controller and the vehicle electronic stability system, and this application does not limit it.

[0067] After receiving the torque signal, the control circuit 110 may adjust the output current of the inverter circuit 120 according to the torque value indicated by the torque signal, thereby adjusting the output torque of the motor 130 .

[0068] It should be noted that the ports in the control circuit 110 include an input terminal, an output terminal, and a communication terminal. Among them, the input terminal, output terminal, and communication terminal in the embodiment of the present application can be specifically implemented as any one of a plurality of ports. A port can also have the functions of input, output, and communication at the same time, and then at least one of the input terminal, output terminal, and communication terminal in the embodiment of the present application can be specifically implemented as the same port, or can be specifically implemented as different ports. Alternatively, the communication port can also be used as a simple input single port or output port. That is, the connection between the input terminal, output terminal, and communication terminal in the embodiment of the present application and other components is only divided by function and is not limited to specific ports in actual applications.

[0069] Exemplarily, the inverter circuit 120 can be a three-phase two-level inverter, a three-phase three-level inverter, or a three-phase multi-level inverter. That is, the embodiment of the present application does not limit the specific implementation of the inverter circuit 120, as long as it can convert the direct current output by the power battery 102 into alternating current for driving the motor 130 to operate.

[0070] The following is an exemplary description of how the control circuit 110 in the embodiment of the present application determines whether it can control the shutdown of multiple switching tubes in the inverter circuit 120 with reference to the accompanying drawings.

[0071] In an embodiment of the present application, the input end of the control circuit 110 is connected to a speed detection device (not shown in the figure), which is arranged on the rotating shaft of the motor 130. Taking the speed detection device as an example in which the speed detection device is specifically implemented as a resolver sensor, the control circuit 110 receives the resolver signal of the resolver sensor according to a preset time period. Exemplarily, the resolver signal may include a sine signal sinα and a cosine signal cosα, where α is the angle rotated by the motor 130. The preset time period can be understood as the sampling period of the control circuit 110, that is, the control circuit 110 collects the sine signal sinα and the cosine signal cosα of the resolver sensor in real time. The control circuit 110 calculates the angle α based on the ratio between the sine signal sinα and the cosine signal cosα. The control circuit 110 also calculates the speed n of the motor 130 based on the angle α and the time t taken for the motor 130 to rotate through the angle α. The formula can be expressed as: N=α / 2πt (1)

[0072] In one embodiment, the control circuit 110 can directly receive a shutdown instruction signal from the vehicle controller 140 and control the shutdown of multiple switches in the inverter circuit 120 based on the shutdown instruction signal. The shutdown instruction signal is generated by the vehicle controller 140 in response to the speed of the motor 130 being less than a first speed value or greater than a second speed value, and the absolute value of the torque demand indicated by the torque signal being less than a preset torque value. The vehicle controller 140 obtains the speed of the motor 130 from the motor controller 104 via the communication bus, obtains the torque signal from other modules via the communication bus, or calculates and generates the torque signal independently. When implementing the method of this embodiment, the motor controller 104 shuts down the switches in the inverter circuit 120 based on the instruction of the vehicle controller 140, thereby minimizing the energy consumption of the motor 130, helping to reduce the energy consumption of the vehicle and improving the vehicle's endurance. At the same time, the motor controller 104 does not need to analyze the vehicle's driving status, which helps to reduce the operating load of the motor controller 104.

[0073] In one embodiment, the control circuit 110 can obtain the torque signal and the speed of the motor 130, determine whether the torque signal and the speed of the motor 130 meet a first preset condition, and control the multiple switch tubes in the inverter circuit 120 to turn off. The first preset condition includes but is not limited to the following two: (1) the speed of the motor is less than a first speed value, and the absolute value of the torque demand indicated by the torque signal is less than a preset torque value; (2) the speed of the motor is greater than a second speed value, and the absolute value of the torque demand indicated by the torque signal is less than a preset torque value. The second speed is greater than the first speed.

[0074] In a specific implementation, the control circuit 110 first determines the driving condition of the vehicle 100 according to the torque signal and the rotational speed of the motor 130 .

[0075] In a specific implementation, when the control circuit 110 determines that the speed of the motor 130 is less than the first speed value for a period longer than the first period, and the absolute value of the torque demand indicated by the torque signal is less than the preset torque value for a period longer than the second period, the control circuit 110 is used to control the multiple switching tubes of the inverter circuit 120 to turn off.

[0076] When the speed of the motor 130 is less than the first speed value for a period longer than the first period, and the absolute value of the torque demand indicated by the torque signal is less than the preset torque value for a period longer than the second period, it can be determined that the driving condition of the vehicle 100 is an idle condition. The idle condition is usually defined as the vehicle being in D gear, the driver steps on the brake pedal, and the vehicle is parked in place, the vehicle does not power off, and remains in a state where it can move forward at any time. The control circuit 110 can obtain the vehicle driving status signal from the vehicle controller 140, wherein the vehicle driving status signal may include but is not limited to a torque signal, a gear signal, a driving mode, an energy feedback mode, a throttle signal, a brake signal, etc. Therefore, the control circuit 110 can further determine the driving condition of the vehicle 100 based on the vehicle driving status signal. For example, the control circuit 110 determines whether the driving condition of the vehicle 100 is an idle condition based on whether the gear position of the vehicle 100 is a preset gear position (such as D gear). That is, when the gear position of the vehicle 100 is a preset gear position (such as D gear), the driving condition of the vehicle 100 is likely to be an idle condition. For another example, the control circuit 110 determines whether the driving condition of the vehicle 100 is an idle condition based on whether the driving mode of the vehicle 100 is a non-performance mode or a non-sports mode. That is, when the driving mode of the vehicle 100 is a non-performance mode or a non-sports mode, the driving condition of the vehicle 100 is likely to be an idle condition. In implementing this embodiment, when the motor controller determines that the vehicle is in an idle condition based on the torque signal and the speed of the motor, it controls the switch tube in the inverter circuit to turn off, that is, to achieve the effect of automatically shutting down the motor controller without human intervention, reducing the energy consumption of the motor, helping to reduce the energy consumption of the entire vehicle, and improving the endurance of the entire vehicle.

[0077] In another implementation, when the control circuit 110 determines that the speed of the motor 130 is greater than the second speed value for a period longer than a third period, and the absolute value of the torque demand indicated by the torque signal is less than the preset torque value for a period longer than the second period, the control circuit 110 controls the multiple switches of the inverter circuit 120 to turn off. When the speed of the motor 130 is greater than the second speed value for a period longer than the third period, and the absolute value of the torque demand indicated by the torque signal is less than the preset torque value for a period longer than the second period, the control circuit 110 may determine that the driving condition of the vehicle 100 is a coasting condition. A coasting condition is generally defined as a state in which the vehicle 100 is moving forward, the vehicle speed is greater than or equal to a specific preset value, and the drive motor 130 rotates with the wheels 190. The control circuit 110 may obtain a vehicle driving status signal from the vehicle controller 140. The vehicle driving status signal includes, but is not limited to, a torque signal, a gear position signal, a driving mode, a regenerative braking mode, a throttle signal, a brake signal, a speed signal, and the like. Therefore, the control circuit 110 can further determine the driving condition of the vehicle 100 based on the vehicle driving state signal. For example, the control circuit 110 determines whether the driving condition of the vehicle 100 is a coasting condition based on whether the speed of the vehicle 100 is greater than a preset speed threshold. That is, when the gear position of the vehicle 100 is greater than the preset speed threshold, the driving condition of the vehicle 100 is likely to be a coasting condition. For another example, the control circuit determines whether the driving condition of the vehicle 100 is a coasting condition based on whether the change value of the speed of the vehicle 100 within a preset time is less than a preset speed change value. That is, when the speed change value of the vehicle 100 is less than the preset speed change value, the driving condition of the vehicle 100 is likely to be a coasting condition. In implementing this embodiment, when the motor controller determines that the vehicle is in a coasting condition based on the torque signal and the speed of the motor, it controls the switch tube in the inverter circuit to turn off, that is, to achieve the effect of automatically shutting down the motor controller without human intervention, reducing the energy consumption of the motor, helping to reduce the energy consumption of the entire vehicle and improving the endurance of the entire vehicle.

[0078] In one embodiment, after controlling the multiple switch tubes in the inverter circuit 120 to turn off, the control circuit 110 sends an actual torque signal of the motor 130 to the vehicle controller 140. The actual torque signal of the motor 130 is used to indicate the torque value actually generated by the motor 130. In an embodiment of the present application, the actual torque signal of the motor 130 may be different from the torque value indicated by the torque signal, and the vehicle controller 140 does not send a warning signal to the driver in response to the torque value indicated by the actual torque signal of the motor being different from the torque value indicated by the torque signal. In this way, when the motor controller controls the multiple switch tubes in the inverter circuit to turn off in order to achieve vehicle energy saving, the vehicle controller does not send an alarm signal to the driver, which helps to simplify the driver's operation and improve the driver's driving experience.

[0079] Among them, the control circuit 110 can also send working information of the motor 130 to the vehicle controller 140. The working information includes but is not limited to the speed of the motor 130, whether the motor 130 is in the intelligent shutdown mode (the intelligent shutdown mode is that the control circuit 110 can automatically control the shutdown of multiple switch tubes in the inverter circuit 120), whether the motor 130 is in the shutdown state (the shutdown state is that multiple switch tubes in the inverter circuit 120 are in the shutdown state), etc.

[0080] In one embodiment, under certain operating conditions, the vehicle controller 140 may further send a disable shutdown instruction signal to the control circuit 110, which is used to instruct the control circuit 110 to disable the control of multiple switch tubes in the inverter circuit 120 from shutting down. For example, when the driver switches the driving mode of the vehicle 100 to the sport mode or the performance mode, the vehicle controller 140 sends the disable shutdown instruction signal to the control circuit 110 to ensure the driving performance of the vehicle and the driver's driving experience. For another example, when the vehicle controller 140 detects that there is a fault in the vehicle 100, it sends the disable shutdown instruction signal to the control circuit 110 to ensure the safety performance of the vehicle.

[0081] In one embodiment, referring to FIG5 , FIG5 shows a schematic diagram of the structure of a vehicle according to an embodiment of the present application. In the schematic diagram of the structure of vehicle 100 shown in FIG5 , vehicle 100 includes the electric drive system shown in FIG3 . Furthermore, vehicle 100 also includes an electronic stability control system 150 , a vehicle braking feedback system 160 , an accelerator pedal 170 , and a brake pedal 180 .

[0082] In an embodiment of the present application, after the control circuit 110 controls multiple switching tubes in the inverter circuit 120 to turn off, the control circuit 110 can also perform real-time detection of the operating condition of the vehicle 100 to determine whether the driver has a torque demand for the vehicle 100. When it is determined that the driver has a torque demand for the vehicle 100, the control circuit 110 can also control multiple switching tubes in the inverter circuit 120 to turn on.

[0083] In one embodiment, the control circuit 110 can directly obtain the received open-tube indication signal from the vehicle controller 140, and control the opening of multiple switch tubes in the inverter circuit 120 according to the open-tube indication signal. The open-tube indication signal is generated by the vehicle controller 140 in response to the absolute value of the change in the speed of the motor 130 within a preset time being greater than the preset speed change value or the absolute value of the torque demand indicated by the torque signal being greater than the preset torque value. The vehicle controller 140 obtains the speed of the motor 130 from the motor controller 104 through the communication bus, obtains the torque signal from other modules through the communication bus, or calculates and generates the torque signal by itself. When the method of this embodiment is implemented, the motor controller quickly opens the switch tubes in the inverter circuit according to the instruction of the vehicle controller to meet the driver's torque demand for the vehicle. At the same time, the motor controller does not need to analyze the vehicle driving status, which helps to reduce the operating load of the motor controller.

[0084] In one embodiment, the control circuit 110 can obtain the torque signal and the speed of the motor 130, determine whether the torque signal and the speed of the motor 130 meet a second preset condition, and control the opening of multiple switches in the inverter circuit 120. The second preset condition includes but is not limited to the following two: (1) the absolute value of the change in the speed of the motor 130 within a preset time is greater than a preset speed change value; (2) the absolute value of the torque demand indicated by the torque signal is greater than a preset torque value.

[0085] In one embodiment, the control circuit 110 continuously obtains the speed of the motor 130. When the absolute value of the change in the speed of the motor 130 within a preset time period is greater than a preset speed change value, the control circuit 110 determines that the vehicle 100 has a real torque demand. The control circuit 110 then controls the multiple switches in the inverter circuit 120 to turn on, providing torque to the vehicle. In this way, when the vehicle has a torque demand, the motor controller controls the multiple switches in the inverter circuit to turn on, outputting current to the motor. This achieves the effect of automatically turning on the motor without human intervention, meeting the driver's power torque demand for the vehicle and improving the safety and reliability of vehicle control.

[0086] In one embodiment, control circuit 110 continuously acquires a torque signal. When the absolute value of the torque demand indicated by the torque signal is greater than a preset torque value, control circuit 110 determines that vehicle 100 has a torque demand and controls multiple switches in inverter circuit 120 to turn on, providing torque to the vehicle. This allows the motor controller to control multiple switches in the inverter circuit to turn on when the vehicle has a real torque demand, outputting current to the motor. This achieves the effect of automatically turning on the motor without human intervention, meeting the driver's torque demand for the vehicle and improving the safety and reliability of vehicle control.

[0087] In one specific implementation, the communication end of the control circuit 110 is used to connect to the vehicle body electronic stability system 150. When the vehicle body electronic stability system 150 detects that the vehicle 100 is unstable (for example, rolling down a slope) and requires emergency braking, the vehicle body electronic stability system 150 sends a torque signal to the control circuit 110. Correspondingly, the control circuit 110 receives the torque signal from the vehicle body electronic stability system 150. The control circuit 110 determines the torque demand indicated by the torque signal. When the absolute value of the torque demand indicated by the torque signal is greater than the preset torque value, the control circuit 110 determines that the vehicle 100 has a real torque demand. The control circuit 110 controls multiple switch tubes in the inverter circuit 120 to turn on and provide torque for the vehicle 100. In this way, the electronic stability system of the vehicle body sends a torque signal to the controller when the vehicle needs to accelerate, brake or there is a risk of slipping when parked. After receiving the torque signal sent by the electronic stability system of the vehicle body, the control circuit determines that the vehicle has a torque demand and controls multiple switching tubes in the inverter circuit to open, thereby achieving the effect of automatic opening of the motor without human intervention, meeting the driver's power torque demand for the vehicle and improving the safety and reliability of vehicle control.

[0088] In a specific implementation, the communication end of the control circuit 110 is used to connect to the vehicle braking feedback system 160. When the vehicle braking feedback system 160 determines that the vehicle 100 has a vehicle feedback braking demand and requires braking force in response to the driver's operation, the vehicle braking feedback system 160 sends a torque signal to the control circuit 110. Correspondingly, the control circuit 110 receives the torque signal sent from the vehicle braking feedback system 160. With reference to the above, the control circuit 110 judges the torque demand indicated by the torque signal. When the absolute value of the torque demand indicated by the torque signal is greater than the preset torque value, the control circuit 110 determines that the vehicle 100 has a real torque demand. The control circuit 110 controls multiple switch tubes in the inverter circuit 120 to turn on and provide torque for the vehicle 100. In this way, after the driver starts the vehicle braking feedback mode, the vehicle braking feedback system sends a torque signal to the control circuit. After receiving the torque signal sent by the vehicle braking feedback system, the controller determines that the vehicle has a vehicle braking feedback requirement, and controls multiple switching tubes in the inverter circuit to open, thereby achieving the effect of automatic opening of the motor without human intervention, meeting the driver's demand for vehicle braking feedback and improving the safety and reliability of vehicle control.

[0089] In one specific implementation, the input end of the control circuit 110 is used to connect to the accelerator pedal 170. In response to the throttle signal generated by the driver pressing the accelerator pedal 170, the control circuit 110 is also used to determine a torque signal based on the throttle signal and the vehicle driving status signal, and to judge the torque demand indicated by the torque signal. When the absolute value of the torque demand indicated by the torque signal is greater than the preset torque value, the control circuit 110 determines that the vehicle 100 has a real torque demand, and the control circuit 110 controls the multiple switches in the inverter circuit 120 to turn on, providing torque for the vehicle 100. In this way, the motor controller directly receives the throttle signal generated by the accelerator pedal trigger, and controls the multiple switches in the inverter circuit to quickly turn on according to the throttle signal, that is, the motor automatically turns on without human intervention, meeting the driver's driving needs. At the same time, the throttle signal transmission link is short, improving the safety and reliability of vehicle control.

[0090] In one specific implementation, the input end of the control circuit 110 is used to connect to the brake pedal 180. In response to the brake signal generated by the driver stepping on the brake pedal 180, the control circuit 110 is also used to determine the torque signal based on the brake signal and the vehicle driving status signal, and judge the torque demand indicated by the torque signal. When the absolute value of the torque demand indicated by the torque signal is greater than the preset torque value, the control circuit 110 determines that the vehicle 100 has a real torque demand, and the control circuit 110 controls the opening of multiple switches in the inverter circuit 120 to provide torque for the vehicle 100. In this way, the motor controller directly receives the brake signal generated by the brake pedal trigger, and controls the rapid opening of multiple switches in the inverter circuit according to the brake signal, that is, the effect of automatic opening of the motor without human intervention is achieved, which meets the driving needs of the driver. At the same time, the brake signal transmission link is short, which improves the safety and reliability of vehicle control.

[0091] In an embodiment of the present application, the control circuit 110 can also adjust the magnitude of the current delivered by the inverter circuit 120 to the motor 130 according to the actual torque demand value of the vehicle 100 to avoid a sense of impact in the vehicle, while enabling the vehicle 100 to quickly respond to the driver's torque demand or the feedback braking demand of the entire vehicle to ensure the safety and reliability of vehicle control.

[0092] In a specific implementation, the control circuit 110 calculates the current value corresponding to the actual torque demand value according to the actual torque demand value of the vehicle 100 based on the relationship between the actual torque demand value and the current. The relationship between torque and current is shown in formula (2):

[0093] T=9550UI / n(2)

[0094] Among them, T is the actual torque demand value; U is the operating voltage of the motor 130, that is, the voltage of the power battery 102; I is the operating current of the motor 130; and n is the speed of the motor 130.

[0095] The control circuit 110 controls the on / off switching of each switch in the inverter circuit 120 so that the output current of the inverter circuit 120 corresponds to the actual torque demand value. At this point, the output torque of the motor 130 corresponds to the actual torque demand value. It should be understood that although the torque value and the current value correspond, the control circuit 110 specifically controls the output current of the inverter circuit 120, while the torque value is output by the motor 130. Due to the limited control accuracy of the control circuit 110, the output current of the inverter circuit 120 may be greater than or less than the calculated standard current value, and the torque value output by the motor 130 may be greater than or less than the actual torque demand value.

[0096] In one embodiment, the control circuit 110 can periodically receive torque signals and vehicle driving status signals from other modules of the vehicle 100 (e.g., the vehicle controller 140, the electronic stability system 150, the vehicle brake feedback system 160, the accelerator pedal 170, and the brake pedal 180). Combined with the periodically acquired speed signal or resolver signal of the motor 130, the control circuit 110 can calculate the actual torque demand value of the vehicle 100. The control circuit 110 can then use the calculated result to directly control the output current of the inverter circuit 120, thereby quickly controlling the output torque of the motor 130. In this way, through periodic and continuous control, the vehicle can avoid the impact sensation and ensure the safety and reliability of vehicle control.

[0097] 6 shows a flow chart of a motor control method 500 according to an embodiment of the present invention. This method is applicable to the control circuit 110 in the motor controller 104. The specific structures and connections between the motor controller 104 and the control circuit 110 can be found above and will not be described in detail here.

[0098] S501, first signal input.

[0099] The first signal includes a motor speed signal and a torque signal. The resolver signal indicates the motor speed, and the torque signal indicates the vehicle's torque requirement. Optionally, the first signal may also include a vehicle driving status signal, which is used to determine the vehicle's driving condition. The vehicle driving status signal includes, but is not limited to, a torque requirement signal, a gear position signal, a driving mode, an energy regenerative mode, a throttle signal, and a brake signal.

[0100] The resolver signal is collected by the control circuit through a speed detection device mounted on the motor's rotor. The vehicle's driving status signal is received by the control circuit from a communication bus, which is connected to the vehicle controller, electronic stability control system, brake feedback system, brake pedal, accelerator pedal, and other components.

[0101] S502: Determine whether a first preset condition is met.

[0102] The first preset condition includes but is not limited to the following two conditions: (1) the motor speed is less than a first speed value, and the absolute value of the torque demand indicated by the torque signal is less than a preset torque value; (2) the motor speed is greater than a second speed value, and the absolute value of the torque demand indicated by the torque signal is less than the preset torque value. The second speed is greater than the first speed.

[0103] The specific process of the control circuit 110 determining whether the first preset condition is satisfied based on the torque signal and the rotational speed of the motor 130 can be referred to the above description, which will not be repeated here for the sake of brevity.

[0104] In a specific implementation, when the control circuit determines that the first preset condition is not satisfied, that is, the judgment result of S502 is no, steps S501 to S502 are executed in a loop. When the control circuit determines that the first preset condition is satisfied, that is, the judgment result of S502 is yes, S503 may be executed.

[0105] S503, controlling multiple switch tubes in the inverter circuit to turn off.

[0106] S504, second signal input.

[0107] The second signal may include part or all of the first signal shown in step S501.

[0108] In one embodiment, the second signal may also include a torque demand signal from the vehicle electronic stability system, a torque signal sent by the vehicle braking feedback system, a brake signal generated by the brake pedal in response to the driver's operation, a throttle signal generated by the accelerator pedal in response to the driver's operation, etc.

[0109] S505: Determine whether a second preset condition is met.

[0110] Among them, the second preset condition includes but is not limited to the following two: (1) the absolute value of the change in the speed of the motor 130 within the preset time is greater than the preset speed change value; (2) the absolute value of the torque demand indicated by the torque signal is greater than the preset torque value.

[0111] The specific process of the control circuit 110 determining whether the second preset condition is satisfied based on the torque signal and the rotational speed of the motor 130 can be referred to the above description, which will not be repeated here for the sake of brevity.

[0112] In a specific implementation, when the control circuit determines that the second preset condition is not satisfied, that is, the judgment result of S505 is no, steps S504 to S505 are executed in a loop. When the control circuit determines that the second preset condition is satisfied, that is, the judgment result of S505 is yes, S506 may be executed.

[0113] S506, controlling multiple switch tubes in the inverter circuit to turn on.

[0114] In a specific implementation, the control circuit starts to output current to the motor by controlling one or more of the multiple switching tubes in the inverter circuit to be turned on.

[0115] In one embodiment, the control circuit calculates the target current based on the actual torque demand value according to the relationship between torque and current shown in formula (2) above. The control circuit controls the on and off of multiple switching tubes in the inverter circuit so that the output current of the inverter circuit 120 is the target current, thereby controlling the torque output by the motor 130 to be the target torque.

[0116] S507: Send the actual torque signal of the motor.

[0117] In a specific implementation, after the control circuit controls multiple switching tubes in the inverter circuit to turn off or on, that is, after executing S503 or S506, it sends the actual torque signal of the motor to the vehicle controller. The actual torque signal of the motor is used to indicate the actual torque value generated by the motor.

[0118] It should be noted that after the multiple switches in the inverter circuit are turned off in S503, although the motor controller stops driving the motor, the motor's rotor magnetic field does not immediately disappear. The remaining rotor magnetic field generates an induced voltage in the motor's stator windings. When it is determined in S505 that the switches need to be turned on to output AC power to the motor, the inverter circuit needs to be restarted because the power transistors in the inverter circuit have already been turned off. If the inverter circuit is started directly, a voltage difference will exist between the output voltage at the midpoint of the inverter circuit's power transistor bridge arm and the induced voltage in the winding. This will cause an inrush current to flow between the motor's stator windings and the midpoint of the inverter circuit's power transistor bridge arm, affecting the normal operation of the inverter circuit's power transistors. Furthermore, direct startup of the inverter circuit requires a certain amount of time, resulting in a certain delay in the startup process. In this case, the control circuit 110 can first output a startup signal to control the inverter circuit to generate a startup voltage. The startup voltage can offset the induced voltage in the motor's stator windings. The startup voltage reduces the inrush current, eliminating the inrush effect during the inverter circuit startup process and significantly accelerating the startup speed. The control circuit 110 then controls the inverter circuit to drive the motor to output torque. This can improve the power performance and driving comfort of electric vehicles.

[0119] In one embodiment, the control circuit can also send the working information of the motor to the vehicle controller. The working information includes but is not limited to the motor speed, whether the motor is in the intelligent shutdown mode (the intelligent shutdown mode is a mode in which the control circuit can automatically control the shutdown of multiple switch tubes in the inverter circuit), whether the motor is in the shutdown state (the shutdown state is that multiple switch tubes in the inverter circuit are in the shutdown state), etc.

[0120] The motor controller provided in this application can control the switching transistors in the inverter circuit to shut down based on the torque signal and the motor's speed. This effectively achieves the effect of automatically shutting down the motor controller without human intervention, reducing motor energy consumption, helping to reduce vehicle energy consumption and improve vehicle range. Furthermore, when the input signal determines that the vehicle has a real torque demand, the controller quickly controls the switching transistors in the inverter circuit to output AC power to the motor to meet the driver's torque demand, thereby improving vehicle driving reliability and stability.

[0121] FIG7 is a schematic flow chart illustrating an example of a control method 600 executed by the control circuit 110. As shown in FIG7 , at S610, the control circuit 110 determines the motor speed. For example, the control circuit 110 may determine the motor speed based on a speed signal indicating the motor speed. The speed signal may be sent to the control circuit by the speed detection device. Alternatively, the speed signal may be sent to the control circuit by the vehicle controller.

[0122] At S620, the control circuit 110 calculates the torque demand. For example, as described above, the control circuit 110 can determine the torque demand based on the brake signal or the throttle signal. For example, the deeper the brake pedal is depressed, the greater the negative torque required. The deeper the throttle pedal is depressed, the greater the positive torque required. Thus, the brake signal or the throttle signal can be correlated with the pedal depression depth, and the torque demand corresponding to the pedal depression depth can be recovered based on the brake signal or the throttle signal.

[0123] At S630 , the control circuit 110 determines whether the speed and torque requirements of the motor meet preset conditions.

[0124] The preset condition is used to determine whether the driver requires the motor to output torque, or in other words, the preset condition is used to determine whether AC power needs to be output to the motor so that the motor outputs torque.

[0125] The preconditions include:

[0126] Condition 1: The speed of the motor is less than a first preset speed value, and the positive torque demand is less than a preset torque value.

[0127] Condition 2: The speed of the motor is greater than a second preset speed value, and the absolute value of the negative torque demand is less than a preset torque value.

[0128] Specifically, when the judgment result of condition 1 is "yes", it can be considered that the vehicle is currently in idle state, that is, the driver does not need the motor to output torque. In this case, S640 is executed, and the control circuit 110 controls the switch in the inverter circuit to disconnect to stop providing AC power to the motor.

[0129] When the determination result of condition 1 is “yes”, it can be considered that the vehicle is currently in a coasting state and there is no need for brake feedback, that is, the driver does not need the motor to output torque. In this case, execute S640.

[0130] FIG8 is a schematic flow chart illustrating another example of a control method 700 executed by the control circuit 110. Unlike the method shown in FIG7 , the torque demand is determined by the vehicle controller based on a brake signal or an accelerator signal, and the torque demand value is transmitted to the control circuit 110 via a torque signal. Furthermore, the method for determining the torque demand by the vehicle controller is similar to that of the control circuit 110, and a detailed description thereof is omitted here to avoid redundancy.

[0131] FIG9 shows a schematic flow chart of another example of a control method 800 executed by the control circuit 110. Unlike the method shown in FIG7 , the torque demand is determined by the vehicle controller based on a brake signal or an accelerator signal, and the process of determining whether the motor speed and torque demand meet preset conditions is performed by the vehicle signal. Furthermore, when the vehicle controller determines, based on the determination result, that it is necessary to stop supplying AC power to the motor, it sends a shutdown instruction signal to the control circuit 110 at S840. The shutdown instruction signal is used to instruct the control circuit 110 to control the switch in the inverter circuit to disconnect. At S850, the control circuit 110 turns off the switch in the inverter circuit according to the shutdown instruction signal to stop supplying AC power to the motor.

[0132] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0133] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0134] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0135] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0136] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A motor controller, characterized in that: The motor controller includes an inverter circuit and a control circuit. The inverter circuit includes three switch tube bridge arms. The two ends of each switch tube bridge arm are used to receive power from a power battery. The midpoint of each switch tube bridge arm is used to connect one phase winding of the three-phase winding of the motor. The control circuit is used to: In response to the absolute value of the torque demand indicated by the torque signal being greater than or equal to a preset torque value, controlling the inverter circuit to output three-phase alternating current; In response to the rotation speed of the motor being less than a first rotation speed value or greater than a second rotation speed value, and the absolute value of the torque demand indicated by the torque signal being less than a preset torque value, controlling a plurality of switch tubes in the inverter circuit to turn off; Wherein, the second rotation speed is greater than the first rotation speed.

2. The motor controller according to claim 1, characterized in that: The control circuit is specifically used for: In response to the motor speed being less than the first speed value for a period longer than a first period, and the absolute value of the torque demand indicated by the torque signal being less than the preset torque value for a period longer than a second period, the multiple switch tubes are controlled to be turned off.

3. The motor controller according to claim 1, characterized in that: The control circuit is specifically used for: In response to the motor speed being greater than the second speed value for a period greater than a third period, and the absolute value of the torque demand indicated by the torque signal being less than a preset torque value for a period greater than a second period, the multiple switch tubes are controlled to be turned off.

4. The motor controller according to any one of claims 1 to 3, characterized in that: The control circuit is also used for: In response to the absolute value of the change in the rotation speed of the motor within the preset time being greater than the preset rotation speed change value, the inverter circuit is controlled to output three-phase alternating current.

5. The motor controller according to any one of claims 1 to 4, characterized in that: The control circuit is also used for: In response to the absolute value of the torque demand indicated by the torque signal being greater than the preset torque value, the inverter circuit is controlled to output three-phase alternating current.

6. The motor controller according to any one of claims 1 to 5, characterized in that: The control circuit is also used for: An indication signal sent by a vehicle controller is received, where the indication signal is used to prohibit or allow the control circuit to control the multiple switch tubes to turn off.

7. The motor controller according to any one of claims 1 to 6, characterized in that: The control circuit is also used for: A rotation speed signal of the motor is received, where the rotation speed signal is used to indicate the rotation speed of the motor.

8. The motor controller according to any one of claims 1 to 7, characterized in that: The control circuit is also used for: A throttle signal generated by triggering an accelerator pedal or a brake signal generated by triggering a brake pedal is received, the throttle signal and the brake signal are respectively used to generate the torque signal, and the direction of the torque demand indicated by the torque signal corresponding to the throttle signal is opposite to the direction of the torque demand indicated by the torque signal corresponding to the brake signal.

9. The motor controller according to any one of claims 1 to 8, characterized in that: The communication end of the control circuit is used to connect to the vehicle body electronic stability system and receive the torque signal sent by the vehicle body electronic stability system.

10. The motor controller according to any one of claims 1 to 9, characterized in that: The communication end of the control circuit is used to connect to the vehicle controller and receive the torque signal sent by the vehicle controller.

11. The motor controller according to any one of claims 1 to 10, characterized in that: The communication end of the control circuit is used to connect to the vehicle controller, and the control circuit is used to: A vehicle driving state signal sent by the vehicle controller is received, and the vehicle driving state signal is used by the control circuit to obtain the torque signal.

12. An electric drive system, characterized in that: The electric drive system comprises a motor controller and a motor as claimed in any one of claims 1 to 11, Wherein, the motor receives three-phase alternating current from the inverter circuit.

13. A vehicle, characterized in that: The vehicle comprises a power battery and an electric drive system as claimed in claim 12, Wherein, the power battery is connected to the input end of the inverter circuit.

Images