WO2018068683A1

WO2018068683A1 - Electric vehicle dynamic coupling system, electric vehicle having same, and control method therefor

Info

Publication number: WO2018068683A1
Application number: PCT/CN2017/105251
Authority: WO
Inventors: 许文科; 陈长红; 何彬
Original assignee: 蔚来汽车有限公司
Priority date: 2016-10-10
Filing date: 2017-10-04
Publication date: 2018-04-19

Abstract

Disclosed are an electric vehicle dynamic coupling system, an electric vehicle having same, and a control method therefor. The electric vehicle dynamic coupling system comprises: a planet gear drive mechanism comprising a sun gear (2), a planet gear (3), a planet carrier (6) and a gear ring (5), wherein the planet carrier (6) is connected to the planet gear (3), and the planet gear (3) meshes with the sun gear (2) and the gear ring (5), respectively; a clutch (4) controlled so as to be engaged with or disengaged from the gear ring (5); a main reduction gear set connected to an output shaft (21) of the planet carrier; a differential (15) connected to an output shaft (18) of the main reduction gear set; a first electric motor (1) driving an input shaft of the sun gear (2) of the planet gear drive mechanism; and a second electric motor (12) controlled so as to drive the gear ring (5) or the output shaft (21) of the planet carrier. The electric vehicle dynamic coupling system can use different working modes in different working conditions, thus meeting different requirements for motor power or rotational speed, etc., and improving the applicability of the electric vehicle.

Description

Electric vehicle power coupling system, electric vehicle therewith and control method thereof

Technical field

The present invention relates to the field of electric vehicles, and more particularly to an electric vehicle power coupling system and a control method therefor.

Background technique

With the deepening of the global energy crisis, the depletion of petroleum resources and air pollution, the danger of rising global temperatures has intensified. Governments and automobile companies generally recognize that energy conservation and emission reduction are the main directions for future automotive technology development. Electric vehicles are increasingly recognized by consumers for their zero emissions, low noise, low cost of use and good economics. At the same time, market share has increased year by year. The existing pure electric vehicle power system mostly adopts a single motor with a fixed transmission ratio gearbox. However, there are many shortcomings in this kind of scheme in practical applications. On the one hand, since the electric vehicle needs a large torque at the start, it is necessary to select a gearbox having a larger transmission ratio. On the other hand, when the electric vehicle runs at a high speed, the transmission of the transmission is required to be relatively small, otherwise it is necessary to select a high-speed drive motor. With a fixed ratio gearbox, it is difficult to optimize the motor operating point, so that the motor always works in the high efficiency zone, affecting the driving range of the electric car. For the two-speed or multi-speed gearbox solution, the control during the shifting process is relatively complicated in order to achieve uninterrupted power. At the same time, consumers are increasingly demanding the cruising range and power of electric vehicles. Therefore, there is now a growing interest in the art of coupling solutions using dual motors in conjunction with gearboxes.

As a type of scheme, the Chinese patent of CN201510166465.9 discloses a dual-motor electric vehicle device and an electric vehicle equipped therewith, which is composed of a first motor, a second motor, a planetary gear transmission mechanism, a deceleration and torque-increasing device, The differential and the controller, the first motor is coupled to the sun gear, and the second motor is coupled to the ring gear, and the outputs of the first and second motors are output by the planet carrier by superposition of the planet wheels. When the vehicle speed is less than the preset value, the first motor is in the motor mode and rotates in the forward direction, and the second motor rotates in the reverse direction and is in the power generation mode to charge the vehicle battery pack; when the vehicle speed is not less than the preset value, the first Both the motor and the second motor operate in the motor mode for forward rotation. The scheme is simple in structure and can realize various working modes, but has the following problem: when the vehicle speed is less than the preset value, the first motor needs to drive the vehicle and drive the second motor to generate electricity, and the overall efficiency is not high.

As another type of scheme, the Chinese patent application No. CN201120535844.8 discloses a dual-motor electric vehicle powertrain system and an electric vehicle equipped therewith, which are connected by the first and second planetary gear transmission mechanisms. a connecting device of the second planetary gear mechanism, a differential connected to the second planetary gear transmission mechanism, and A first motor coupled to the sun gear is coupled to the first planetary gear transmission, and a second motor is coupled to the ring gear of the first planetary gear transmission. In the electric traction mode, when the torque demand is less than a preset value, the second clutch is engaged to fix the input ring gear to input torque through the first motor, otherwise the second clutch is disengaged to release the input ring gear, and the first The clutch engages through two motors to output torque. Although it can realize the speed coupling of the two motors, the mechanical structure using the two rows of planetary gears is relatively complicated.

Summary of the invention

It is an object of the present invention to provide an electric vehicle power coupling system.

It is still another object of the present invention to provide an electric vehicle having the electric vehicle power coupling system.

It is still another object of the present invention to provide a control method for the electric vehicle power coupling system.

According to an aspect of the present invention, an electric vehicle power coupling system is further provided, comprising: a planetary gear transmission mechanism including a sun gear, a planetary gear, a carrier, and a ring gear; wherein the carrier connects the planetary gear And the planet gears mesh with the sun gear and the ring gear, respectively; a clutch that is controlled to engage or disengage the ring gear; a final reduction gear set that is coupled to an output shaft of the planet carrier; a differential coupled to an output shaft of the final reduction gear set; a first motor that drives an input shaft of a sun gear of the planetary gear mechanism; and a second motor that is controlled to drive the ring gear or The output shaft of the planet carrier.

Optionally, further comprising: a first gear set, the driven gear meshes with the ring gear; a second gear set whose driven gear is coupled to an output shaft of the carrier; and a synchronizer that is The second motor is driven and movable between the first engaged position, the second engaged position, and the disengaged position; wherein, in the first engaged position, the synchronizer is engaged with the first gear set, at this time The second motor drives the ring gear; in the second engaged position, the synchronizer is engaged with the second gear set, at which time the second motor drives an output shaft of the planet carrier; In the disengaged position, the synchronizer is not engaged with the first gear set or the second gear set.

Optionally, further comprising a third gear set, the second motor driving an input shaft of the third gear set; the first gear set and the driving gear of the second gear set are respectively sleeved in the first gear set An output shaft of the three-gear set; wherein, when the synchronizer is moved to the first engaged position, a drive gear of the first gear set is coupled to an output shaft of the third gear set; movement at the synchronizer The drive gear of the second gear set is coupled to the output shaft of the third gear set to the second engaged position.

Optionally, a drive gear of the final reduction gear set is coupled to an output shaft of the planet carrier, and a driven gear of the final reduction gear set is coupled to the differential.

Optionally, the first motor has a power greater than the second motor, and the second motor has It is greater than the rotational speed of the first motor.

According to another aspect of the present invention, there is also provided an electric vehicle comprising an electric vehicle power coupling system as described above, and a wheel connected to the differential via a half shaft.

According to still another aspect of the present invention, there is provided a control method for an electric vehicle, comprising the electric vehicle as described above, the control method comprising: a speed coupling mode, the first motor driving the sun gear of the planetary gear mechanism Input shaft; and the second motor drives the ring gear of the planetary gear transmission; the torque is transmitted to the wheel via the output shaft of the planetary carrier of the planetary gear transmission, the final reduction gear set, and the differential; and/or the torque a coupling mode, the first motor drives an input shaft of the sun gear of the planetary gear mechanism; and the second motor is controlled to drive an output shaft of the planet carrier; the first motor transmits torque to the output shaft of the planet carrier and is coupled to The torque coupling transmitted by the two motors is thereafter transmitted to the wheel via the main reduction gear set and the differential; and/or the first motor operates in a separate mode, the first motor drives the input shaft of the sun gear of the planetary gear transmission, and in turn The output shaft of the planet carrier of the planetary gear mechanism, the main reduction gear set, and the differential are transmitted to the wheels.

Optionally, in the speed coupling mode, the first motor and the second motor are turned on, the clutch is separated from the ring gear; and the synchronizer is moved to the first engaged position to connect the second motor to the ring gear; and/or at the torque In the coupled mode, the first motor and the second motor are turned on, the clutch is engaged with the ring gear; and the synchronizer is moved to the second engaged position to connect the second motor to the carrier output shaft; and/or in the first motor alone mode of operation Next, the first motor is turned on, the second motor is stopped, the clutch is engaged with the ring gear, and the synchronizer is moved to the disengaged position, so that the second motor is disconnected.

Optionally, in the speed coupling mode, when the brake pedal is moved to the braking position, the first motor and/or the second motor enters a power generation mode; and/or in the torque coupling mode, the brake pedal moves to the brake In position, the first motor and/or the second motor enters a generating mode; and/or in the first motor alone mode of operation, the first motor enters a generating mode when the brake pedal is moved to the braking position.

Optionally, the speed coupling mode and the torque coupling mode are mutually switched by the first motor single working mode.

According to the electric vehicle power coupling system and the electric vehicle of the present invention, different working modes can be used under different working conditions, thereby satisfying different requirements for motor power or rotational speed, and greatly improving the applicability of the electric vehicle. For example, when starting on a flat road, at low speeds, the controllable system can enter the first motor's separate operating mode to take full advantage of the performance of the first motor. For example, during cruising or high-speed driving, the control system can enter the speed coupling mode, and the speed coupling of the two motors can be realized by the planetary gear mechanism, and the second motor can be used for stepless speed regulation, so that the first motor can work in the high efficiency region, thereby improving Economical, increase mileage. Another example is the torque demand When larger, the system can be controlled to enter the torque coupling mode for better acceleration performance and gradeability.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of one embodiment of an electric vehicle power coupling system of the present invention.

2 is a schematic illustration of one embodiment of a control system of the present invention.

detailed description

Figure 1 shows a schematic diagram of one embodiment of the electric vehicle power coupling system. Specifically, the electric vehicle power coupling system of this embodiment includes: a first motor 1, a sun gear 2, a planetary gear 3, a clutch 4, a ring gear 5, a carrier 6, a drive gear 7 of the first gear set, and a synchronizer. 8. The drive gear 9 of the second gear set, the input shaft 10, the third gear set drive gear 11, the second motor 12, the wheel 13, the half shaft 14, the differential 15, the driven gear 16 of the third gear set, The drive gear 17 of the main reduction gear set, the output shaft 18, the driven gear 19 of the final reduction gear set, the driven gear 20 of the second gear set, the output shaft 21, and the driven gear 22 of the first gear set. In this system, different parts of the system can be driven by using different motors to control the rotation of the first motor 1, the start and stop of the second motor 12, the engagement and disengagement of the clutch 4, and the synchronized position of the synchronizer 8 Moment coupling, speed coupling, single motor operation and other working modes are used to adapt to different working conditions.

Among them, the sun gear 2, the planetary gear 3, the ring gear 5 and the planet carrier 6 constitute a planetary gear transmission mechanism, and the planetary gear 3 includes four gears evenly distributed along the circumference of the carrier 6, and is not limited to four gears. The planet gear 3 simultaneously meshes with the outer edge of the sun gear 2 and the inner edge of the ring gear 5. The planet carrier 6 is fixedly connected to the output shaft 21. The output shaft 21 is fixedly coupled to the drive gear 17 of the final reduction gear set. The driving gear 17 of the main reduction gear set meshes with the driven gear 19 of the main reduction gear set to function as a deceleration and augmentation. The driven gear 19 of the main reduction gear set and the output shaft 18 are fixedly connected. The output shaft 18 outputs power to the wheels 13 via the differential 15 and the right and left half shafts 14.

As one of the power sources, the motor output shaft of the first motor 1 is fixedly coupled to the sun gear 2. Thus, the wheels 13 can be driven in sequence via the sun gear 2, the planet gears 3, the carrier 6 output shaft 21, the drive gear 17, the driven gear 19, the output shaft 18, the differential 15, and the half shaft 14.

As another power source, the motor output shaft of the second motor 12 is fixedly coupled to the drive gear 11 of the third gear set, and the drive gear 11 of the third gear set meshes with the driven gear 16 of the third gear set, the third gear set The driven gear 16 is fixedly coupled to the input shaft 10, and the drive gear 7 of the first gear set and the drive gear 9 of the second gear set are sleeved on the input shaft 10. The drive gear 7 and the driven gear 22 of the first gear set mesh to form a gear pair. The drive gear 9 and the driven gear 20 of the second gear set mesh to form a gear pair. Synchronizer 8 can be input The shaft 10 is moved left and right to different positions: when moving to the left to the first engaged position, the synchronizer 8 is engaged with the drive gear 7 of the first gear set, thereby realizing engagement of the drive gear 7 of the first gear set with the input shaft 10 . When moving to the right to the second engaged position, the synchronizer 8 engages with the drive gear 9 of the second gear set, thereby effecting engagement of the drive gear 9 of the second gear set with the input shaft 10. When the synchronizer 8 is moved to the intermediate separated position, the input shaft 10 and the drive gear 7 of the first gear set and the drive gear 9 of the second gear set are not engaged.

Optionally, the first motor 1 is a main motor having a higher power and a rotational speed; and the second motor 12 is an auxiliary motor, and a high-speed motor having a smaller power is used. More specifically, the first motor 1 has a greater power than the second motor 12, and the second motor 12 has a higher rotational speed than the first motor 1.

2 is a schematic diagram of electrical connections of one embodiment of an electric vehicle power coupling system of the present invention. The system further includes a controller 23, which can be in communication with the first motor 1, the second motor 12, the clutch 4, and the synchronizer 8, respectively, to achieve complete vehicle control. The controller 23 can determine the specific working mode of the electric vehicle according to the input signals of various sensors and the like in the brake pedal, the accelerator pedal and the electric vehicle, and control the first motor 1 and the second according to the actual situation of the various working modes. Start and stop of the motor 12; separation/engagement of the clutch 4; and positional movement of the synchronizer 8. Further, the first motor 1 single working mode and the double motor speed coupling mode and the torque coupling mode are realized.

Several working modes are further explained as follows:

When the first motor single operation mode is executed, the controller 23 controls the first motor to be turned on, the second motor is stopped, the control clutch 4 is engaged with the ring gear 5, and the synchronizer 8 is controlled to move to the separated position. At this time, the planetary gear 3 has only one degree of freedom, and the first motor 1 inputs a torque through the sun gear 2 and outputs a torque via the carrier 6. Further, the wheel 13 is further driven via the output shaft 21, the drive gear 17 of the final reduction gear set, the driven gear 19 of the final reduction gear set, the output shaft 18, the differential 15 and the half shaft 14. And the controller 23 controls the synchronizer 8 to move to the disengaged position, at which time the drive gear 7 of the first gear set and the drive gear 9 and the input shaft 10 of the second gear set are separated from each other to transmit the torque from the second motor 12. The second motor 12 is turned off.

In the first motor single mode of operation, when the first motor 1 is in the motor state, it can be used for conditions such as a flat start.

Further, if the brake pedal is stepped on and the vehicle is braked, the first motor 1 will be in a power generating state to charge the battery. It can be used to brake energy recovery.

Further, when the electric vehicle is in the reverse gear, the first motor 1 operates alone, the clutch 4 is engaged with the ring gear 5, the synchronizer 8 is moved to the disengaged position, and the driving gear of the first gear set and the driving gear of the second gear set 9 are separated. And the first motor 1 is reversed, thereby implementing the reverse mode.

When the speed coupling mode is executed, the controller 23 controls the first motor and the second motor to be turned on, and the control clutch 4 is separated from the ring gear 5 and controls the synchronizer 8 to move to the left to the first engagement position. The synchronizer 8 is engaged with the drive gear 7 of the first gear set such that the input shaft 10 is engaged with the drive gear 7 of the first gear set, since the drive gear 7 of the first gear set meshes with the driven gear 22, the driven gear 22 drives the ring gear 5. At this time, the ring gear 5 will be driven by the second motor 12. At the same time, the sun gear 2 is driven via the first electric machine 1. Therefore, the first motor 1 and the second motor 12 can realize the rotational speed coupling by the planetary gear mechanism.

In this mode, the rotational speed of the first motor 1 is n ₁ , the rotational speed of the second motor 12 is n ₂ , the number of teeth Z _{1 of the} sun gear, the number of teeth of the ring gear is Z ₂ , the drive gear 7 of the first gear set and the follower transmission gear ratio 22 i _1, transfer driven gear and the third gear set 11 drive gear 16 of the third gear set ratio i _3, the rotational speed of the output shaft 21 is:

n _out =[n ₁ +(K*n ₂ )/(i ₁ *i ₃ )]/(1+K);

Where K = Z ₂ / Z ₁ .

At this time, the infinitely variable speed can be realized by adjusting the rotation speed of the second motor 12, so that the first motor 1 operates in the high efficiency zone to extend the cruising range, and is mainly used for cruising or high speed working conditions.

Further, when the electric vehicle runs in the speed coupling mode and steps on the brake pedal, the controller 23 can control the first motor 1 and the second motor 12 to generate electricity according to the actual operating conditions of the battery to charge the battery. It can be used to brake energy recovery. For example, the input power is generated by the output shaft 18, the driven gear 19 of the final reduction gear set, the drive gear 17 of the final reduction gear set, the output shaft 21, the carrier 6, and the first motor 1 is driven by the sun gear 2 to generate electricity; The other passes through the ring gear 5, the driven gear 22, the drive gear 7 of the first gear set, the driven gear 16 of the third gear set, and the drive gear 11 of the third gear set drives the second electric machine 12 to generate electricity. Thereby, the dual motor is charged to the battery.

When the torque coupling mode is executed, the controller 23 controls the first motor and the second motor to be turned on, and the control clutch 4 engages with the ring gear 5 and controls the synchronizer 8 to move the second engaged position to the right. The synchronizer 8 is engaged with the drive gear 9 of the second gear set to engage the input shaft 10 with the drive gear 9 of the second gear set. The second motor 12 drives the output shaft 21 by the engagement of the drive gear 9 and the driven gear 20 of the second gear set. At the same time, the first electric machine 1 outputs torque from the carrier 6 via the sun gear 2 to drive the output shaft 21. The first motor 1 and the second motor 12 are in turn enabled to implement a torque coupling mode on the output shaft 21.

In this mode, the output torque of the first motor 1 is T ₁ , the output torque of the second motor 12 is T ₂ , the transmission ratio i ₃ of the drive gear 11 of the third gear set and the driven gear 16 of the third gear set, The transmission ratio i ₂ of the driving gear 9 of the second gear set and the driven gear 20 and the output torque of the output shaft 21 are:

T _out = T ₁ * (1 + K) + T ₂ * i ₃ * i ₂ .

At this time, it can meet the demand for high torque of electric vehicles, and is mainly used for rapid acceleration or climbing conditions.

Further, when the electric vehicle is running in the torque coupling mode, when the brake pedal is stepped on, the controller 23 can control the first motor 1 and the second motor 12 to generate electricity according to the actual working condition of the battery to charge the battery. It can be used to brake energy recovery. For example, the input power is generated via the output shaft 18, the driven gear 19 of the final reduction gear set, the drive gear 17 of the final reduction gear set, the output shaft 21, all the way through the carrier 6, and the sun gear 2 drags the first motor 1 to generate electricity; The other passes through the driven gear 20, the drive gear 9 of the second gear set, the driven gear 16 of the third gear set, and the drive gear 11 of the third gear set drives the second electric machine 12 to generate electricity. Thereby, the dual motor is charged to the battery.

In the switching process of the foregoing three working modes, the transition from the speed coupling mode to the torque coupling mode needs to pass the first motor single working mode. The specific process: when transitioning from the speed coupling mode to the first motor single working mode, the second motor 12 is unloaded, the synchronizer 8 is separated from the driving gear 7 of the first gear set, and the driving gear 7 of the first gear set is idling while the clutch 4 is engaged with the ring gear 5. At this time, the power is input from the first motor 1, and is output via the sun gear 2, the carrier 6, and the output shaft 21. When transitioning from the first motor single working mode to the torque coupling mode, the controller 23 adjusts the rotational speed of the second motor 12 when its rotational speed n ₂ is equal to the rotational speed n _{21 of the} output shaft ₂₁ multiplied by the driving gear 11 of the third gear set and transfer driven gear of the third gear set 16 drive gear ratio i ₃ of the second gear set and the gear 9 and the driven gear 20 ratio i _2, i.e.

n ₂ =n ₂₁ *i ₂ *i ₃

If the two are not equal, an adjustment torque T=I*(dw/dt) is applied to the second motor 12, where I is the moment of inertia of the rotating component of the second motor 12, dw=n ₂₁ *i ₂ *i ₃ -n ₂ , for the difference in speed between the two. When the two speeds are equal, the torque of the second motor is unloaded. When the torque is 0, the synchronizer 8 is engaged with the driving gear 9 of the second gear set, and the input shaft 10 is coupled with the driving gear 9 of the second gear set, and the rotational speed of the output shaft 21 is controlled by the controller 23 according to the first motor 1 The current speed is divided by (1 + Z ₂ / Z ₁ ). At this time, the power is provided by the first motor 1 and the second motor 12 to implement the torque coupling mode, respectively. The first motor 1 has a constant transmission path, and the power output by the second motor 12 passes through the driving gear 11 of the third gear set, the driven gear 16 of the third gear set, the driving gear 9 of the second gear set, and the driven gear. , 20, output shaft 21 output. The wheel 13 is driven by the driving gear 17 of the main reduction gear set, the driven gear 19 of the final reduction gear set, the output shaft 18, the differential 15 and the half shaft 14.

The transition from the torque coupling mode to the speed coupling mode also passes through the first motor 1 separate operation mode. Specifically, when transitioning from the torque coupling mode to the first motor 1 alone, the torque of the second motor 12 is first unloaded. The synchronizer 8 is separated from the drive gear 9 of the second gear set, and the drive gear 9 of the second gear set is idling. At this time, the clutch 4 is still engaged with the ring gear 5, and at this time, the power is output from the first motor 1, and is output through the sun gear 2, the carrier 6, and the output shaft 21. When the first motor 1 transitions from the single operation to the speed coupling mode, the controller 23 causes the speed of the second motor 12 to be 0, the synchronizer 8 engages with the drive gear 7 of the first gear set, and the input shaft 10 and the first gear The driving gears 7 of the group are connected while the clutch 4 is separated from the ring gear 5, and the controller 23 controls the output of the second motor 12, at which time the output of the first motor 1 is supplied to the sun gear 2, and the output of the second motor 12 is input. The shaft 10, the driving gear 7 of the first gear set and the driven gear 22 are coupled to the rotational speed via the ring gear 5 and output via the carrier 6 and the output shaft 21. The wheel 13 is then driven via the drive gear 17 of the final reduction gear set, the driven gear 19 of the final reduction gear set, the output shaft 18, the differential 15 and the half shaft 14.

The first motor separately operating mode can also be referred to the above process when transitioning to the torque coupling or the speed coupling mode, and therefore will not be described herein.

In summary, in the switching transition of different modes, the controller realizes the effect of no power interruption during the switching process by adjusting the second motor speed, the synchronizer and the clutch to work together.

The above examples mainly illustrate the electric vehicle power coupling system of the present invention, the electric vehicle having the same, and the control method therefor. Although only a few of the embodiments of the present invention have been described, it will be understood by those skilled in the art that the invention may be practiced in many other forms without departing from the spirit and scope of the invention. Accordingly, the present invention is to be construed as illustrative and not restrictive, and the invention may cover various modifications without departing from the spirit and scope of the invention as defined by the appended claims With replacement.

Claims

An electric vehicle power coupling system, comprising:

a planetary gear transmission mechanism comprising a sun gear, a planet gear, a planet carrier and a ring gear; wherein the planet carrier is coupled to the planet gear, and the planet gears respectively mesh with the sun gear and the ring gear;

a clutch that is controlled to engage or disengage the ring gear;

a main reduction gear set connected to an output shaft of the planet carrier;

a differential connected to an output shaft of the main reduction gear set;

a first motor that drives an input shaft of a sun gear of the planetary gear mechanism;

A second motor that is controlled to drive the ring gear or the output shaft of the planet carrier.
The electric vehicle power coupling system according to claim 1, further comprising:

a first gear set, the driven gear meshes with the ring gear;

a second gear set having a driven gear coupled to an output shaft of the planet carrier;

a synchronizer driven by the second motor and movable between a first engaged position, a second engaged position, and a disengaged position;

Wherein in the first engaged position, the synchronizer is engaged with the first gear set, at which time the second motor drives the ring gear; in the second engaged position, the synchronizer and the The second gear set is engaged, at which time the second motor drives an output shaft of the planet carrier; in the disengaged position, the synchronizer is not engaged with the first gear set or the second gear set.
The electric vehicle power coupling system according to claim 2, further comprising a third gear set, said second motor driving an input shaft of said third gear set; said first gear set and said first The driving gears of the two gear sets are respectively sleeved on the output shaft of the third gear set;

Wherein, when the synchronizer moves to the first engaged position, the driving gear of the first gear set is coupled to the output shaft of the third gear set; when the synchronizer moves to the second engaged position, A drive gear of the second gear set is coupled to an output shaft of the third gear set.
The electric vehicle power coupling system according to any one of claims 1 to 3, wherein a driving gear of the main reduction gear set is coupled to an output shaft of the carrier, and a slave of the main reduction gear set A moving gear is coupled to the differential.
The electric vehicle power coupling system according to any one of claims 1 to 3, wherein the first motor has a larger power than the second motor, and the second motor has a larger than the first motor Speed.
An electric vehicle characterized by comprising the electric vehicle power coupling system according to any one of claims 1 to 5, and a wheel connected to the differential via a half shaft.
A control method for an electric vehicle, comprising the electric vehicle according to claim 6, wherein the control method comprises:

In the speed coupling mode, the first motor drives the input shaft of the sun gear of the planetary gear transmission; and the second motor drives the ring gear of the planetary gear transmission; the torque sequentially passes through the output shaft of the planet carrier of the planetary gear transmission, and the main reduction gear Groups, differentials are transmitted to the wheels; and/or

In the torque coupling mode, the first motor drives the input shaft of the sun gear of the planetary gear transmission; and the second motor is controlled to drive the output shaft of the carrier; the torque transmitted by the first motor is transmitted to the output shaft of the carrier and The torque coupling transmitted by the second motor is thereafter transmitted to the wheel via the main reduction gear set and the differential; and/or

The first motor is in a separate working mode, and the first motor drives the input shaft of the sun gear of the planetary gear transmission, and is sequentially transmitted to the wheel via the output shaft of the planetary carrier of the planetary gear transmission, the main reduction gear set, and the differential.
The control method according to claim 7, wherein:

In the speed coupling mode, the first motor and the second motor are turned on, the clutch is separated from the ring gear; and the synchronizer is moved to the first engaged position, so that the second motor is coupled to the ring gear; and/or

In the torque coupling mode, the first motor and the second motor are turned on, the clutch is engaged with the ring gear; and the synchronizer is moved to the second engaged position such that the second motor is coupled to the planet carrier output shaft; and/or

In the first motor single mode of operation, the first motor is turned on, the second motor is stopped, the clutch is engaged with the ring gear, and the synchronizer is moved to the disengaged position such that the second motor is disconnected.
The control method according to claim 7 or 8, wherein:

In the speed coupling mode, when the brake pedal is moved to the braking position, the first motor and/or the second motor enters a power generation mode; and/or

In the torque coupling mode, when the brake pedal is moved to the braking position, the first motor and/or the second motor enters a power generation mode; and/or

In the first motor single mode of operation, when the brake pedal is moved to the braking position, the first motor enters a power generation mode.
The control method according to claim 7 or 8, wherein the speed coupling mode and the torque coupling mode are mutually switched by the first motor independent operation mode.