Hybrid electric vehicles, dual-motor controllers and their control methods

Abstract

This application provides a hybrid electric vehicle, a dual-motor controller, and a control method thereof. The control method first determines whether the first drive circuit connected to the generator's power connection terminal is operating in a voltage closed-loop control mode. When the first drive circuit is operating in voltage closed-loop control mode, it indicates a fault in the high-voltage power battery and that the contactor connected to the DC bus is disconnected. At this time, based on the hybrid electric vehicle's limp-drive mode, and with the goal of stabilizing the DC bus voltage, the operating mode or power limit of the second drive circuit is determined. That is, through the coordinated control of the first and second drive circuits, the voltage on the DC bus is maintained stably, avoiding the DC bus voltage fluctuation problem that easily occurs when relying solely on the first drive circuit to control the DC bus voltage.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a hybrid electric vehicle, a dual-motor controller, and a control method thereof. Background Technology

[0002] Hybrid electric vehicles (HEVs) are gaining popularity among consumers due to their low fuel consumption and lack of range anxiety. Meanwhile, the architecture of HEVs is becoming increasingly complex, with many adopting a dual-motor hybrid control architecture, typically P1+P2 or P1+P3. P1 is a generator used to charge the high-voltage battery; P2 or P3 is a drive motor used to propel the vehicle. The generator and drive motor can be controlled by a dual-motor controller, whose DC side is connected to the high-voltage battery via a DC bus. Furthermore, the high voltage output from the high-voltage battery to the DC bus is usually directly converted to low voltage using a DC / DC converter to charge the low-voltage battery, thus eliminating the need for the low-voltage generator found in traditional gasoline vehicles.

[0003] If the high-voltage power battery fails, the contactor connecting it to the DC bus will disconnect, causing the dual-motor controller and the DC / DC converter to lose their power source. When the low-voltage battery power is depleted, the vehicle can only remain stationary and wait for rescue, posing a significant risk. To address this issue, existing technologies typically employ a control scheme that switches the generator to a voltage closed-loop control mode, enabling it to output a stable high voltage to the DC bus for the DC / DC converter, thus allowing the vehicle to limp to a safe area or repair shop.

[0004] However, when the high-voltage power battery fails or the contactor disconnects, the dual-motor controller is essentially losing a large capacitor bank, and the DC bus voltage is prone to fluctuation. Summary of the Invention

[0005] In view of this, this application provides a hybrid electric vehicle, a dual-motor controller, and a control method thereof to avoid the problem of DC bus voltage fluctuation.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] The first aspect of this application provides a control method for a dual-motor controller, wherein the dual-motor controller is used to control the operation of a generator and a drive motor in a hybrid electric vehicle, the power connection terminal of the generator is connected to the DC bus in the dual-motor hybrid control architecture of the hybrid electric vehicle through a first drive circuit, and the power connection terminal of the drive motor is connected to the DC bus through a second drive circuit; the control method includes:

[0008] Determine whether the first drive circuit is operating in voltage closed-loop control mode;

[0009] If the first drive circuit operates in the voltage closed-loop control mode, the operating mode or power limit of the second drive circuit is determined based on the vehicle limp-drive mode of the hybrid electric vehicle, with the goal of stabilizing the voltage of the DC bus.

[0010] Optionally, based on the limp-drive mode of the hybrid vehicle and with the goal of stabilizing the voltage of the DC bus, the operating mode or power limit of the second drive circuit is determined, including:

[0011] If the vehicle limp drive mode is that the engine of the hybrid vehicle drives the vehicle through a closed clutch, then the operating mode of the second drive circuit is determined with the goal of stabilizing the voltage of the DC bus.

[0012] If the vehicle limp-drive mode is that the engine drives the generator to generate electricity and the drive motor drives the vehicle to run, then the power limit of the second drive circuit is determined with the goal of stabilizing the voltage of the DC bus.

[0013] Optionally, to stabilize the voltage of the DC bus, the operating mode of the second drive circuit is determined, including:

[0014] The operating mode of the second drive circuit is determined to be off.

[0015] Optionally, to stabilize the voltage of the DC bus, the operating mode of the second drive circuit is determined, including:

[0016] The operating mode of the second drive circuit is determined to be zero torque control mode.

[0017] Optionally, to stabilize the voltage of the DC bus, the operating mode of the second drive circuit is determined, including:

[0018] Determine whether the speed of the hybrid vehicle is less than a preset speed;

[0019] If the vehicle speed is less than the preset speed, then the operating mode of the second drive circuit is determined to be off;

[0020] If the vehicle speed is greater than or equal to the preset speed, then the operating mode of the second drive circuit is determined to be zero torque control mode.

[0021] Optionally, to stabilize the voltage of the DC bus, the power limit of the second drive circuit is determined, including:

[0022] If the second drive circuit transmits electrical energy from the DC bus to the drive motor, then the power limit is determined to be a first power limit; the first power limit is less than or equal to the difference between the power of the first drive circuit and the power of the DC / DC converter connected to the DC bus.

[0023] If the second drive circuit transmits electrical energy from the drive motor to the DC bus, then the power limit is determined to be a second power limit; the second power limit is less than or equal to the difference between the power of the DC / DC converter and the power of the first drive circuit.

[0024] Optionally, if the vehicle limp-drive mode is that the engine drives the generator to generate electricity and the drive motor drives the vehicle, then while determining the power limit of the second drive circuit with the goal of stabilizing the voltage of the DC bus, it also includes:

[0025] The step size of the change in the execution torque of the drive motor is limited to be less than or equal to a first preset step size.

[0026] Optionally, if the vehicle limp-drive mode is that the engine drives the generator to generate electricity and the drive motor drives the vehicle, then in addition to determining the power limit of the second drive circuit, it also includes:

[0027] The current between the DC bus and the second drive circuit is used as the feedforward quantity for the voltage closed-loop control of the first drive circuit.

[0028] Based on the voltage of the DC bus and the rotational speed of the generator, the feedforward quantity is converted to obtain the feedforward torque;

[0029] The feedforward torque is superimposed on the regulating torque output by the regulator in the voltage closed-loop control to obtain the execution torque, which is used as the output of the voltage closed-loop control.

[0030] Optionally, if the vehicle limp-drive mode is that the engine drives the generator to generate electricity and the drive motor drives the vehicle, then in addition to determining the power limit of the second drive circuit, it also includes:

[0031] The step size for the change in the generator's operating torque is limited to be greater than or equal to a second preset step size.

[0032] Optionally, if the vehicle limp-drive mode is that the engine drives the generator to generate electricity and the drive motor drives the vehicle, then in addition to determining the power limit of the second drive circuit, it also includes:

[0033] The generator's torque is limited by setting zero as the maximum amplitude, and the result after limiting is used as the output of the voltage closed-loop control of the first drive circuit.

[0034] A second aspect of this application provides a dual-motor controller, comprising: a first control unit and a second control unit; wherein...

[0035] The output terminal of the first control unit is connected to the control terminal of the first drive circuit. The DC side of the first drive circuit is connected to the DC bus in the dual-motor hybrid control architecture of the hybrid vehicle. The AC side of the first drive circuit is connected to the power connection terminal of the generator in the hybrid vehicle.

[0036] The output terminal of the second control unit is connected to the control terminal of the second drive circuit, the DC side of the second drive circuit is connected to the DC bus, and the AC side of the second drive circuit is connected to the power connection terminal of the drive motor in the hybrid vehicle.

[0037] The first control unit is communicatively connected to the second control unit to execute the control method of the dual-motor controller as described in any of the first aspects above; wherein the two control units respectively control the operation of the corresponding drive circuit and monitor the operation mode control of the corresponding drive circuit by the other control unit.

[0038] Optionally, it may also include: a third control unit, used to realize information interaction between the dual-motor controller and other controllers;

[0039] The communication rate between the control units within the dual-motor controller is greater than the communication rate between the dual-motor controller and other controllers, and the difference between the two is greater than a preset difference value.

[0040] Optionally, each control unit can be either a different core within the same microcontroller unit (MCU) or a different MCU that is connected via communication.

[0041] Optionally, the first drive circuit and the second drive circuit are integrated into the dual-motor controller.

[0042] A third aspect of this application provides a hybrid electric vehicle whose dual-motor hybrid control architecture includes: an engine, a generator, a drive motor, a clutch, a high-voltage power battery, a DC / DC converter, a low-voltage battery, and a dual-motor controller as described in any of the second aspects above; wherein,

[0043] The engine is connected to the generator and also connected to the drive motor and the gearbox in the hybrid vehicle via the clutch;

[0044] The power connection terminal of the generator is connected to the DC bus through the first drive circuit;

[0045] The power connection terminal of the drive motor is connected to the DC bus through the second drive circuit;

[0046] The first drive circuit and the second drive circuit are respectively controlled by the corresponding control unit in the dual motor controller;

[0047] The high-voltage power battery is connected to the DC bus via a contactor;

[0048] The low-voltage battery is connected to the DC bus via the DC / DC converter.

[0049] Optionally, its hybrid vehicle controller (HCU) is also used to limit the vehicle speed below a preset speed when the vehicle is driven by the engine through the closed clutch in limp drive mode.

[0050] The control method of the dual-motor controller provided in this application first determines whether the first drive circuit connected to the power connection terminal of the generator is operating in voltage closed-loop control mode. When the first drive circuit is operating in voltage closed-loop control mode, it indicates that the high-voltage power battery is faulty and the contactor connected to the DC bus is disconnected. At this time, according to the limp-drive mode of the hybrid electric vehicle, the operating mode or power limit of the second drive circuit is determined with the goal of stabilizing the DC bus voltage. That is, through the coordinated control of the first drive circuit and the second drive circuit, the voltage on the DC bus is stabilized together, avoiding the DC bus voltage fluctuation problem that is easy to occur when relying solely on the first drive circuit to control the DC bus voltage. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0052] Figure 1 This is a schematic diagram of the structure of the dual-motor hybrid control architecture in a hybrid electric vehicle provided in an embodiment of this application;

[0053] Figure 2 A flowchart of the control method for the dual-motor controller provided in the embodiments of this application;

[0054] Figure 3 Another flowchart of the control method for the dual-motor controller provided in the embodiments of this application;

[0055] Figure 4This is a schematic diagram of the common DC bus in the dual-motor hybrid control architecture provided in the embodiments of this application;

[0056] Figure 5 A logic block diagram of voltage closed-loop control provided in an embodiment of this application;

[0057] Figure 6 This is a schematic diagram of the control unit portion of a dual-motor controller provided in an embodiment of this application. Detailed Implementation

[0058] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] In this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0060] In existing hybrid vehicle architectures, single-motor modes are more common than dual-motor modes. Furthermore, current solutions for dual-motor hybrid control architectures primarily focus on how to transition to a voltage-closed-loop control mode for the generator after a high-voltage battery failure, with very little attention paid to how the dual-motor controller should operate within this voltage-closed-loop control mode.

[0061] Considering that in a dual-motor hybrid control architecture, the drive circuits of the generator and drive motor share a DC bus with the DC / DC converter, all three have a significant impact on the DC bus voltage. If this is not taken into account, undervoltage or overvoltage faults may be directly reported during the voltage closed-loop control process, causing the entire vehicle to malfunction and shut down. Therefore, this application provides a control method for a dual-motor controller to avoid the problem of DC bus voltage fluctuations.

[0062] See Figure 1The power connection terminal of the generator (P1 motor shown in the figure) 101 is connected to the DC bus in the dual-motor hybrid control architecture of the hybrid vehicle through the first drive circuit 201; the power connection terminal of the drive motor (such as the TM motor shown in the figure) 102 is connected to the DC bus through the second drive circuit 202; in addition, the low-voltage battery 302 is also connected to the DC bus through the DC / DC converter 203; that is, the first drive circuit 201, the second drive circuit 202 and the DC / DC converter 203 share the same DC bus.

[0063] The dual-motor controller 200 can control the operation of the generator 101 by controlling the operation of the first drive circuit 201; and can control the operation of the drive motor 102 by controlling the operation of the second drive circuit 202. In practical applications, the first drive circuit 201 and the second drive circuit 202 can be integrated inside the dual-motor controller 200 (e.g., Figure 1 As shown in the figure, they can also be set in the drivers of the corresponding motors (not shown), as long as they are controlled by the dual motor controller 200, depending on the specific application environment, and all are within the protection scope of this application.

[0064] When the high-voltage power battery 301 malfunctions and its contactor K1 connected to the DC bus disconnects, the voltage on the DC bus is prone to fluctuation due to the aforementioned common DC bus. At this time, simply controlling the first drive circuit 201 to operate in voltage closed-loop control mode is insufficient to ensure voltage stability on the DC bus. Therefore, the following can be executed: Figure 2 The control method of the dual-motor controller shown includes:

[0065] S101. Determine whether the first drive circuit is operating in voltage closed-loop control mode.

[0066] In practical applications, in Figure 1 In the dual-motor controller 200 shown, the corresponding control units 211 and 212 can be used to control the two drive circuits 201 and 202 respectively. The two control units 211 and 212 can be different cores within the same multi-core MCU (Microcontroller Unit), or they can be different single-core MCUs using a high-speed internal communication mechanism, depending on the specific application environment. No limitation is made here.

[0067] The two control units not only control the operation of their respective drive circuits, but also monitor the operation mode control of the corresponding drive circuit by the other control unit. For example, the second control unit 212 controls the operation of the second drive circuit 202 and monitors the operation mode control of the first drive circuit 201 by the first control unit 211. When the first control unit 211 controls the first drive circuit 201 to operate in voltage closed-loop control mode, the second control unit 212 can be informed of this situation through communication between the two control units.

[0068] If the first drive circuit operates in voltage closed-loop control mode, it means Figure 1 If the high-voltage power battery 301 shown in the figure is faulty and its contactor K1 connected to the DC bus is disconnected, then S102 is executed.

[0069] S102. Based on the limp-drive mode of the hybrid electric vehicle, and with the goal of stabilizing the voltage of the DC bus, determine the operating mode or power limit of the second drive circuit.

[0070] That is, in Figure 1 The first control unit 211 controls the first drive circuit 201 to operate in the voltage closed-loop control mode, while the second control unit 212 simultaneously controls the second drive circuit 202 to operate in the operating mode or power limit determined in S102. Thus, through the coordinated control of the two drive circuits 201 and 202, the DC bus voltage can be better stabilized.

[0071] The control method of the dual-motor controller provided in this embodiment maintains the stability of the DC bus voltage through the coordinated control of the first drive circuit and the second drive circuit, avoiding the DC bus voltage fluctuation problem that is easy to occur when relying solely on the first drive circuit to control the DC bus voltage.

[0072] It is worth noting that in practical applications, due to the presence of the drive motor in the above dual-motor hybrid control architecture, the vehicle limp can be achieved in different ways. In addition to the method commonly used in single-motor hybrids, which involves closing the clutch and having the engine drive the vehicle, the method of disengaging the clutch and relying on the drive motor to drive the vehicle can also be adopted.

[0073] That is, the limp-drive method of the vehicle described in the previous embodiment can be one of the following two methods:

[0074] (1) The engine of a hybrid electric vehicle drives the entire vehicle through a closed clutch;

[0075] See Figure 1Specifically, the engine 401 drives the wheels through the closed clutch 402 and gearbox 403, thereby driving the entire vehicle. At this time, S102 in this control method specifically aims to stabilize the voltage of the DC bus and determine the operating mode of the second drive circuit.

[0076] In addition, in this mode, the engine 401 will simultaneously drive the generator 101 to generate electricity. The generator 101 transmits electrical energy to the DC bus through the first drive circuit 201, and then supplies power to low-voltage equipment such as the low-voltage battery 302 through the DC / DC converter 203.

[0077] (2) The engine drives the generator to generate electricity, which in turn drives the electric motor to drive the vehicle.

[0078] See Figure 1 Specifically, the method is as follows: the engine 401 drives the generator 101 to generate electricity. The generator 101 transmits electrical energy to the DC bus through the first drive circuit 201. Part of this electrical energy is supplied to low-voltage devices such as the low-voltage battery 302 through the DC / DC converter 203, and the other part is used to drive the drive motor 102 to run electrically. Then, the gearbox 403 drives the wheels, thereby driving the entire vehicle. At this time, S102 in this control method specifically aims to stabilize the voltage of the DC bus and determines the power limit of the second drive circuit.

[0079] The following section provides a detailed explanation of the operation and control of the second drive circuit under the two vehicle limp-drive modes.

[0080] In the first type of vehicle limp drive mode, the operating mode of the second drive circuit can be determined to be either off or zero torque control mode.

[0081] In practical applications, the HCU (Hybrid Control Unit) can send generator voltage mode control commands to the dual motor controller. At this time, the drive motor is equivalent to interference relative to the DC bus voltage. Therefore, it is necessary to avoid the second drive circuit from affecting the DC bus voltage as much as possible.

[0082] When the second control unit detects that the first drive circuit is operating in voltage closed-loop control mode, it can directly shut down the second drive circuit, for example, by performing waveform blocking on the second drive circuit, thereby shutting down the drive motor; at this time, the drive motor will not have any impact on the voltage closed-loop control of the first drive circuit.

[0083] It should be noted that due to the presence of anti-parallel diodes in each switch of the second drive circuit, even when the second drive circuit is turned off, the drive motor will still generate a certain back electromotive force (EMF) k*ψ*n on the DC bus through the corresponding anti-parallel diodes in the second drive circuit when the vehicle speed is high. Here, ψ is the motor flux linkage, n is the rotational speed, and k is the back EMF coefficient, the value of which is related to factors such as the gearbox gear ratio and tire radius. If this back EMF k*ψ*n exceeds the DC bus voltage value Udc under the control of the dual-motor controller, it will affect the voltage closed-loop control of the first drive circuit. Therefore, at this time, the vehicle can control the engine speed and gearbox gear to keep the vehicle speed n below the preset speed, thereby ensuring that the back EMF k*ψ*n of the drive motor does not exceed the current DC bus voltage value Udc. In other words, when the engine drives the vehicle in a limp position, the vehicle speed needs to be limited to prevent the drive motor from interfering with the voltage closed-loop control of the first drive circuit.

[0084] In addition, when the second control unit monitors that the first drive circuit is operating in voltage closed-loop control mode, it can also determine that the second drive circuit is operating in zero torque control mode. Ideally, when the second drive circuit is operating in zero torque control mode, the drive motor neither consumes electrical energy nor generates electricity, and will not interfere with the DC bus voltage. However, in actual applications, when the drive motor is running at zero torque, the operation of the switching transistor in the second drive circuit will still cause some fluctuations in the DC bus voltage.

[0085] Therefore, it is preferable to directly shut down the drive motor when the vehicle speed n is lower than the preset speed, and to use a zero-torque control scheme for the drive motor when the vehicle speed n is greater than or equal to the preset speed. In this case, the control method is described in [reference needed]. Figure 3 In the first type of vehicle limp drive mode, S102 of the control method specifically includes:

[0086] S201. Determine whether the speed of the hybrid vehicle is less than the preset speed.

[0087] If the vehicle speed is less than the preset speed, execute S202; if the vehicle speed is greater than or equal to the preset speed, execute S203.

[0088] S202. Determine that the operating mode of the second drive circuit is off.

[0089] S203. Determine that the operating mode of the second drive circuit is zero torque control mode.

[0090] That is, under the first type of vehicle limp drive mode, the dual-motor hybrid electric vehicle should also consider the operation of the drive motor. Otherwise, at different vehicle speeds, the drive motor will have a significant impact on the DC bus voltage, and it is difficult to control the stability of the DC bus voltage solely through the voltage closed-loop control of the first drive circuit. Specifically, when the vehicle speed n is lower than the preset speed, the drive motor is turned off; when it is necessary to exceed the preset speed, the drive motor is controlled to operate with zero torque to minimize the voltage closed-loop interference of the drive motor on the first drive circuit.

[0091] In the second type of vehicle limp drive mode, the drive motor drives the vehicle to run while keeping the clutch in the disengaged state, and the vehicle power is provided by the drive motor. At this time, the vehicle gradually changes the target torque of the drive motor according to the driver's throttle opening. In order to reduce the impact of the drive motor on the voltage controlled by the generator voltage closed loop during operation, the two control units in the dual motor controller can coordinate to maintain the stability of the DC bus voltage.

[0092] At this point, with the goal of stabilizing the DC bus voltage, the power limit of the second drive circuit is determined. Specifically, this can be determined based on the power transmission direction of the second drive circuit. That is, this step can specifically include: if the second drive circuit transmits power from the DC bus to the drive motor, then the power limit is determined to be a first power limit; the first power limit is less than or equal to the difference between the power of the first drive circuit and the power of the DC / DC converter connected to the DC bus; if the second drive circuit transmits power from the drive motor to the DC bus, then the power limit is determined to be a second power limit; the second power limit is less than or equal to the difference between the power of the DC / DC converter and the power of the first drive circuit.

[0093] The second control unit of the drive motor needs to monitor the real-time operating mode and real-time power generation P of the first drive circuit. Gen Once it is determined that the first control unit has switched to the voltage closed-loop control mode, in order to maintain the stability of the DC bus voltage, i.e., the voltage across the bus capacitor, the second control unit needs to impose the following restrictions:

[0094] See Figure 4 When the second drive circuit 202 transmits electrical energy from the DC bus to the drive motor 102, the directions of currents I1, I2, and I3 are as shown by the arrows in the figure. At this time, the power generation P of the first drive circuit 201 is... Gen The power P of the second drive circuit 202 TM and the power P of the DC / DC converter 203 DCDC The following relationship exists between them: P Gen =P TM +P DCDC Among them, the power P of the DC / DC converter 203 DCDCThe value is always positive, which needs to meet the power demand of the low-voltage battery 302. In practical applications, it can also simultaneously meet the power demand of other low-voltage devices in the vehicle. This is not limited here; its specific real-time value can be sent to the dual-motor controller by the HCU. Furthermore, at this time, the power P of the second drive circuit 202... TM With the power P of DC / DC converter 203 DCDC The sum of these values ​​should be less than the power generation P of the first drive circuit 201. Gen That is, it needs to be restricted to: P TM <P Gen -P DCDC In practical applications, to provide a certain control margin for the system, a certain power adjustment space can be reserved. For example, P can be limited. TM <k*(P Gen -P DCDC That is, the first power limit can be set to k*(P) Gen -P DCDC ), where k is a value less than 1, for example, it can be chosen as 80%.

[0095] If the vehicle is in braking mode or coasting energy recovery mode, the second drive circuit transmits electrical energy from the drive motor to the DC bus, and the drive motor is in generator mode. The power output P of the first drive circuit is [not specified]. Gen The power generation P of the second drive circuit TM and the power P of the DC / DC converter DCDC The following relationship exists between them: P TM +P Gen =P DCDC Therefore, it is necessary to limit the power generation P of the second drive circuit. TM Make it satisfy: P TM <P DCDC -P Gen Similarly, in order to provide the system with a certain control margin, a certain power regulation space needs to be reserved, which can limit P. TM <k*(P DCDC -P Gen That is, the second power limit can be set to k*(P) Gen -P DCDC ), where k is a value less than 1, for example, it can be chosen as 80%.

[0096] It should be noted that, in order to prevent the power P of the drive motor TM If a drastic change occurs, while executing S102, the torque change step size TorqStep of the drive motor can be limited to be less than or equal to the first preset step size, that is, a smaller change step size TorqStepMin can be used.

[0097] In addition, when the first control unit switches to the voltage closed-loop control mode, the response speed of the voltage closed-loop control mode can be further accelerated in order to quickly adjust the DC bus voltage.

[0098] In practical applications, the first control unit can also monitor the current between the second drive circuit and the DC bus (e.g., through information interaction with the second control unit) Figure 4 As shown in I3), the first control unit can obtain the real-time current between the DC bus and the second drive circuit, and then use it as a feedforward quantity in the voltage closed-loop calculation of the first drive circuit, directly converting it into the output torque of the voltage closed-loop control, thereby improving the voltage closed-loop response speed of the first drive circuit.

[0099] Specifically, in the second type of vehicle limp drive mode, the control method, while executing S102, may also include: using the current between the DC bus and the second drive circuit (such as...) Figure 4 As shown in Figure I3), the feedforward quantity is used as the voltage closed-loop control feedforward quantity of the first drive circuit. Then, the feedforward quantity is converted according to the DC bus voltage and the generator speed to obtain the feedforward torque. The feedforward torque is then superimposed on the regulating torque output by the regulator in the voltage closed-loop control to obtain the execution torque, which is used as the output quantity of the voltage closed-loop control.

[0100] See Figure 4 The first drive circuit 201, the second drive circuit 202, and the DC / DC converter 203 share a common DC bus. To ensure that the DC bus voltage is constant, it is sufficient to ensure that the sum of the currents between the DC bus and the three components, I1+I2+I3=0. Figure 5 The diagram shown is the corresponding logic block diagram in the first control unit, where the current I3 is used as the feedforward quantity for the voltage closed-loop control of the first drive circuit; the regulator in this voltage closed-loop control can be a proportional-derivative regulator (i.e., Figure 5 The PI regulator shown is used to adjust the DC bus voltage and feedback voltage to obtain the adjusted torque. The conversion processing link in the voltage closed-loop control is used to convert the feedforward quantity according to the DC bus voltage Udc and the generator speed. The specific conversion process can be: multiply the current I3 and the DC bus voltage Ud, divide by the generator speed, and then divide by a fixed coefficient 9.55 to obtain the feedforward torque.

[0101] Since the torque loop is equivalent to the inner loop of the control system in the voltage closed-loop system, in order to speed up the voltage closed-loop control response speed of the generator, the torque response speed of the inner loop can also be accelerated. At this time, it is necessary to speed up the execution torque step size. Specifically, it can be to limit the change step size of the generator's execution torque to be greater than or equal to the second preset step size, that is, to use a larger set change step size TorqStepMax.

[0102] Furthermore, since the generator is always in a generating state under voltage closed-loop control mode, the execution torque output by this voltage closed-loop control must always be negative. Therefore, to improve voltage control accuracy, the execution torque output by this voltage closed-loop control can be further limited, restricting its maximum amplitude to 0. That is, while executing S102, the control method can also include: limiting the generator's execution torque to zero as the maximum amplitude, and using the limited result as the output of the voltage closed-loop control of the first drive circuit.

[0103] As described above, when the drive motor causes the vehicle to limp, the DC bus voltage can be stabilized by limiting the output power and generator power of the drive motor. The torque step size can also be reduced to limit the corresponding power change rate. Simultaneously, for the generator's voltage closed-loop control, the current between the second drive circuit connected to the drive motor and the DC current can be added as feedforward. This can also accelerate the generator's torque loop response speed, improving torque output response speed and enabling rapid adjustment of the DC bus voltage, ensuring its stability. Furthermore, the generator's torque can be limited to improve voltage control accuracy. In practical applications, when the drive motor causes the vehicle to limp, multiple methods can be used simultaneously to coordinate the control of the generator and drive motor, jointly maintaining DC bus voltage stability.

[0104] Another embodiment of this application also provides a dual-motor controller, see [link to relevant documentation] Figure 1 or Figure 6 It includes: a first control unit 211 and a second control unit 212; wherein:

[0105] The output terminal of the first control unit 211 is connected to the control terminal of the first drive circuit 201. The DC side of the first drive circuit 201 is connected to the DC bus in the dual-motor hybrid control architecture of the hybrid vehicle. The AC side of the first drive circuit 201 is connected to the power connection terminal of the generator 101 in the hybrid vehicle.

[0106] The output terminal of the second control unit 212 is connected to the control terminal of the second drive circuit 202. The DC side of the second drive circuit 202 is connected to the DC bus, and the AC side of the second drive circuit 202 is connected to the power connection terminal of the drive motor 102 in the hybrid vehicle.

[0107] The first control unit 211 is communicatively connected to the second control unit 212 to execute the control method of the dual-motor controller as described in any of the above embodiments; the specific process and principle of the control method can be found in the above embodiments, and will not be repeated here.

[0108] See Figure 1 A preferred control method is as follows: if the engine 401 is used to drive the vehicle in limp mode, the drive motor 102 is turned off when the vehicle speed is lower than the preset speed; when it is necessary to exceed the preset speed, the drive motor 102 operates with zero torque to minimize the interference of the drive motor 102 on the voltage closed loop of the generator 101. If the drive motor 102 is used to drive the vehicle in limp mode, a scheme can be adopted to limit the power of the drive motor 102 and reduce the torque step size; furthermore, a scheme can be adopted to use the current between the drive motor 102 and the DC bus as feedforward for the voltage closed loop control of the first driving power 201 and increase the torque step size, and a scheme can be adopted to limit the maximum value of the execution torque of the voltage closed loop control output to 0.

[0109] Two control units control the operation of their respective drive circuits and monitor the operation mode control of the corresponding drive circuit by the other control unit, i.e., they receive control from the other control unit regarding the operating state of the corresponding drive circuit. Specifically, the first control unit 211 controls the operation of the first drive circuit 201 and monitors the operation mode control of the second drive circuit 202 by the second control unit 212, receiving control from the second control unit 212 regarding the operating state of the second drive circuit 202. Figure 6 The TM operating state is shown in the diagram; the second control unit 212 controls the operation of the second drive circuit 202 and monitors the operating mode control of the first control unit 211 on the first drive circuit 201, and receives the operating state of the first drive circuit 201 controlled by the first control unit 211, such as... Figure 6 The P1 operating status is shown in the figure.

[0110] In practical applications, see Figure 6 The dual-motor controller may further include a third control unit 213. This third control unit 213 is used to realize information interaction between the dual-motor controller and other controllers, performing communication reception and transmission. For example, it receives instructions sent by the HCU, including generator voltage mode control instructions, and sends these instructions to the corresponding control units, such as sending TM instructions to the second control unit 212 and P1 instructions to the first control unit 211. Furthermore, the communication rate between the control units within the dual-motor controller is greater than the communication rate between the dual-motor controller and other controllers, and the difference between the two is greater than a preset difference value.

[0111] Furthermore, the control units in this dual-motor controller can be different cores within the same MCU (such as...). Figure 6 (as shown), or, different MCUs with communication connections (such as...) Figure 1 (As shown in the diagram). That is, the dual-motor controller can be implemented using a single multi-core controller or multiple single-core controllers. The multiple single-core controllers use a high-speed internal communication mechanism, as long as the two control units can communicate quickly.

[0112] It should be noted that the first drive circuit 201 and the second drive circuit 202 can be integrated into the dual-motor controller (e.g., Figure 1 As shown in the diagram, the motors can also be separately installed in the drivers of the corresponding motors (not shown in the diagram), as long as they are controlled by the dual-motor controller, they are all within the protection scope of this application.

[0113] Figure 6 Only the control unit portion of the dual-motor controller is shown, using a three-core MCU as an example. Core 1 acts as the first control unit 211, controlling the first drive circuit 201 to operate the generator 101. Core 2 acts as the second control unit 212, controlling the second drive circuit 202 to operate the drive motor 102. Core 3 serves as the third control unit 213, enabling information exchange between the dual-motor controller and other vehicle components; for example, it can receive commands from the HCU. The three cores can communicate with each other at a much higher speed than the communication speed between the dual-motor controller and the HCU. Because the DC bus voltage changes rapidly in the voltage closed-loop control mode, high-speed communication between the cores allows for rapid exchange of operating status information between the drive motor 102 and the generator 101, enabling coordinated control of both and better stabilization of the DC bus voltage.

[0114] When the high-voltage power battery 301 fails and its contactor K1 connected to the DC bus is disconnected, the dual-motor controller is essentially losing a large capacitor bank, and the voltage on the DC bus is prone to fluctuation. The dual-motor controller provided in this embodiment uses a multi-core MCU or multiple MCUs connected through a bus to coordinate with each other, so that the data between the drive motor 102 and the generator 101 can be quickly exchanged, so as to coordinate the control of the DC bus voltage stability.

[0115] Another embodiment of this application also provides a hybrid electric vehicle, whose dual-motor hybrid control architecture is as follows: Figure 1 As shown, it specifically includes: an engine 401, a generator 101, a drive motor 102, a clutch 402, a high-voltage power battery 301, a DC / DC converter 203, a low-voltage storage battery 302, and a dual-motor controller 200 as described in any of the above embodiments; wherein:

[0116] The engine 401 is connected to the generator 101 and is also connected to the drive motor 102 and the gearbox 403 in the hybrid vehicle via the clutch 402.

[0117] The power connection terminal of the generator 101 is connected to the DC bus through the first drive circuit 201; the power connection terminal of the drive motor 102 is connected to the DC bus through the second drive circuit 202; the first drive circuit 201 and the second drive circuit 202 are respectively controlled by the corresponding control units in the dual motor controller 200.

[0118] The high-voltage power battery 301 is connected to the DC bus via contactor K1.

[0119] The low-voltage battery 302 is connected to the DC bus via the DC / DC converter 203; a bus capacitor C is connected between the positive and negative terminals of the DC bus.

[0120] If the engine 401 is used to drive the vehicle in a limp-like manner, the drive motor 102 will be shut off when the vehicle speed is below the preset speed; when it is necessary to exceed the preset speed, the drive motor 102 will operate with zero torque to minimize the interference of the drive motor 102 on the voltage closed loop of the generator 101. This satisfies the limp-like requirement while minimizing the interference of the drive motor 102 on the voltage closed loop stability of the first drive circuit 201; it also meets the driving requirements at higher vehicle speeds.

[0121] In practical applications, in addition to realizing the various functions in the existing technology, the HCU of this hybrid vehicle can also be used to limit the vehicle speed to below a preset speed when the vehicle is driven by the engine 401 through the closed clutch 402 in the limp drive mode.

[0122] If the drive motor 102 is used to drive the vehicle in a limp-like manner, a scheme can be adopted to limit the power of the drive motor 102 and reduce the torque step size to reduce the disturbance of the drive motor 102 to the DC bus voltage. Furthermore, a scheme can be adopted to use the current between the drive motor 102 and the DC bus as feedforward for the voltage closed-loop control of the first drive circuit 201 and increase the torque step size, as well as to limit the maximum value of the execution torque of the voltage closed-loop control output to 0, thereby improving the speed of the voltage closed-loop control.

[0123] The dual-motor controller 200 utilizes the advantage of rapid communication between the two control units. While maintaining a common DC bus voltage, the two control units coordinate with each other to stabilize the overall system output voltage. This makes the DC bus voltage more stable than simply relying on the voltage closed-loop control mode of the first drive circuit 201.

[0124] Similar or identical parts between the various embodiments in this specification can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the description of the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. 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 the modules can be selected to achieve the purpose of this embodiment solution according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0125] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0126] The features described above regarding the disclosed embodiments can be substituted for or combined with each other to enable those skilled in the art to implement or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a dual-motor controller, characterized in that, The dual-motor controller is used to control the operation of the generator and drive motor in the hybrid electric vehicle. The power connection terminal of the generator is connected to the DC bus in the dual-motor hybrid control architecture of the hybrid electric vehicle through a first drive circuit, and the power connection terminal of the drive motor is connected to the DC bus through a second drive circuit. The dual-motor controller includes a first control unit and a second control unit. The first control unit controls the operation of the first drive circuit, and the second control unit controls the operation of the second drive circuit. The first control unit and the second control unit are communicatively connected. The control method includes: The second control unit monitors the first control unit's control over the operating mode of the first drive circuit to determine whether the first drive circuit is operating in voltage closed-loop control mode. If the first drive circuit operates in the voltage closed-loop control mode, the second control unit determines the operating mode or power limit of the second drive circuit based on the vehicle limp-drive mode of the hybrid electric vehicle, with the goal of stabilizing the voltage of the DC bus; the first control unit obtains the current between the DC bus and the second drive circuit through information interaction with the second control unit, and uses the current as the feedforward quantity for the voltage closed-loop control of the first drive circuit.

2. The control method of the dual-motor controller according to claim 1, characterized in that, The second control unit, based on the limp-drive mode of the hybrid vehicle and with the goal of stabilizing the voltage of the DC bus, determines the operating mode or power limit of the second drive circuit, including: If the vehicle limp drive mode is that the engine of the hybrid vehicle drives the vehicle through a closed clutch, then the second control unit determines the operating mode of the second drive circuit with the goal of stabilizing the voltage of the DC bus. If the vehicle limp-drive mode is that the engine drives the generator to generate electricity and the drive motor drives the vehicle to run, then the second control unit determines the power limit of the second drive circuit with the goal of stabilizing the voltage of the DC bus.

3. The control method of the dual-motor controller according to claim 2, characterized in that, The second control unit, with the goal of stabilizing the voltage of the DC bus, determines the operating mode of the second drive circuit, including: The operating mode of the second drive circuit is determined to be off.

4. The control method of the dual-motor controller according to claim 2, characterized in that, The second control unit, with the goal of stabilizing the voltage of the DC bus, determines the operating mode of the second drive circuit, including: The operating mode of the second drive circuit is determined to be zero torque control mode.

5. The control method of the dual-motor controller according to claim 2, characterized in that, The second control unit, with the goal of stabilizing the voltage of the DC bus, determines the operating mode of the second drive circuit, including: The second control unit determines whether the speed of the hybrid vehicle is less than a preset speed; If the vehicle speed is less than the preset speed, the second control unit determines that the operating mode of the second drive circuit is off; If the vehicle speed is greater than or equal to the preset speed, the second control unit determines that the operating mode of the second drive circuit is zero torque control mode.

6. The control method of the dual-motor controller according to claim 2, characterized in that, The second control unit, with the goal of stabilizing the voltage of the DC bus, determines the power limit of the second drive circuit, including: If the second drive circuit transmits electrical energy from the DC bus to the drive motor, the second control unit determines the power limit as a first power limit; the first power limit is less than or equal to the difference between the power of the first drive circuit and the power of the DC / DC converter connected to the DC bus. If the second drive circuit transmits electrical energy from the drive motor to the DC bus, the second control unit determines the power limit as a second power limit; the second power limit is less than or equal to the difference between the power of the DC / DC converter and the power of the first drive circuit.

7. The control method of the dual-motor controller according to claim 2, characterized in that, If the vehicle limp-drive mode is characterized by the engine driving the generator to generate electricity and the drive motor operating electrically to drive the vehicle, then while the second control unit determines the power limit of the second drive circuit with the goal of stabilizing the voltage of the DC bus, it also includes: The second control unit limits the change step size of the drive motor's execution torque to be less than or equal to a first preset step size.

8. The control method for a dual-motor controller according to any one of claims 2 to 7, characterized in that, If the vehicle limp-drive mode is characterized by the engine driving the generator to generate electricity and the drive motor operating electrically to drive the vehicle, then the second control unit, while determining the power limit of the second drive circuit, also includes: The first control unit converts the feedforward quantity according to the voltage of the DC bus and the speed of the generator to obtain the feedforward torque; The first control unit superimposes the feedforward torque onto the regulating torque output by the regulator in the voltage closed-loop control to obtain the execution torque, which is used as the output of the voltage closed-loop control.

9. The control method for a dual-motor controller according to any one of claims 2 to 7, characterized in that, If the vehicle limp-drive mode is characterized by the engine driving the generator to generate electricity and the drive motor operating electrically to drive the vehicle, then the second control unit, while determining the power limit of the second drive circuit, also includes: The first control unit limits the step size of the change in the generator's operating torque to be greater than or equal to a second preset step size.

10. The control method of the dual-motor controller according to any one of claims 2 to 7, characterized in that, If the vehicle limp-drive mode is characterized by the engine driving the generator to generate electricity and the drive motor operating electrically to drive the vehicle, then the second control unit, while determining the power limit of the second drive circuit, also includes: The first control unit limits the generator's torque by setting zero as the maximum amplitude, and uses the limited result as the output of the voltage closed-loop control of the first drive circuit.

11. A dual-motor controller, characterized in that, include: First control unit and second control unit; wherein... The output terminal of the first control unit is connected to the control terminal of the first drive circuit. The DC side of the first drive circuit is connected to the DC bus in the dual-motor hybrid control architecture of the hybrid vehicle. The AC side of the first drive circuit is connected to the power connection terminal of the generator in the hybrid vehicle. The output terminal of the second control unit is connected to the control terminal of the second drive circuit, the DC side of the second drive circuit is connected to the DC bus, and the AC side of the second drive circuit is connected to the power connection terminal of the drive motor in the hybrid vehicle. The first control unit is communicatively connected to the second control unit to execute the control method of the dual-motor controller as described in any one of claims 1 to 10; wherein the two control units respectively control the operation of the corresponding drive circuit and monitor the operation mode control of the corresponding drive circuit by the other control unit.

12. The dual-motor controller according to claim 11, characterized in that, Also includes: The third control unit is used to realize information interaction between the dual-motor controller and other controllers; The communication rate between the control units within the dual-motor controller is greater than the communication rate between the dual-motor controller and other controllers, and the difference between the two is greater than a preset difference value.

13. The dual-motor controller according to claim 11 or 12, characterized in that, Each control unit is either a different core within the same microcontroller unit (MCU) or a different MCU that is connected via communication.

14. The dual-motor controller according to claim 11 or 12, characterized in that, The first drive circuit and the second drive circuit are integrated into the dual-motor controller.

15. A hybrid electric vehicle, characterized in that, Its dual-motor hybrid control architecture includes: an engine, a generator, a drive motor, a clutch, a high-voltage power battery, a DC / DC converter, a low-voltage battery, and a dual-motor controller as described in any one of claims 11 to 14; wherein, The engine is connected to the generator and also connected to the drive motor and the gearbox in the hybrid vehicle via the clutch; The power connection terminal of the generator is connected to the DC bus through the first drive circuit; The power connection terminal of the drive motor is connected to the DC bus through the second drive circuit; The first drive circuit and the second drive circuit are respectively controlled by the corresponding control unit in the dual motor controller; The high-voltage power battery is connected to the DC bus via a contactor; The low-voltage battery is connected to the DC bus via the DC / DC converter.

16. The hybrid electric vehicle according to claim 15, characterized in that, Its hybrid vehicle controller (HCU) is also used to limit the vehicle speed below a preset speed when the vehicle is driven by the engine through the closed clutch in limp drive mode.

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