DE202015104054U1 - Electric system of an electric vehicle and electric vehicle - Google Patents

Abstract

Drive system of an electric car, comprising:
a drive battery;
an engine and a first clutch connected to the engine;
an input shaft, a first output shaft and a second output shaft;
a main reduction gear and a second clutch, wherein the main reduction gear is connected to the first clutch via the input shaft;
a front wheel drive subsystem comprising a first motor / generator and a first planetary gear, the first motor / generator connected to the drive battery and the first planetary gear connected to the first motor / generator, the first output shaft and the second clutch;
a rear wheel drive subsystem comprising a second motor / generator and a second planetary gear, the second motor / generator connected to the drive battery and the second planetary gear connected to the second motor / generator, the second output shaft and the second clutch; and
a control unit configured to control the engine, the first motor / generator, and the second motor / generator according to an operation mode of the electric car.

Description

TERRITORY

The present disclosure relates to automotive engineering, and more particularly to an electric car drive system and an electric car.

BACKGROUND

The hybrid drive type of the present hybrid automobile can hardly be adjusted in real time, so that adaptation to different traffic information is difficult. And the shock during the mode change and gear shift process is larger, so driving is not comfortable.

The real-time four-wheel drive solution in related technologies is to allocate the power from the front-wheel and rear-wheel power source via a force distribution device in real-time to accommodate different traffic information. In the real-time four-wheel drive solution, however, a transmission is required so that the acceleration of the vehicle and the highest speed can be realized by shifting the transmission, but the function of a continuously variable transmission can not be realized. It is difficult to operate the engine for a long time in the range of high efficiency, which is unfavorable in terms of optimizing the operating point of the engine. In addition, the power transmission efficiency of the system and the efficiency of the brake energy recirculation in the all-electric mode are low, and the timely adjustment of the ratio between the front and rear axle brake feedback can not be realized according to the road conditions, thus resulting in poor braking stability Has.

SUMMARY

The present disclosure aims to solve at least one of the above problems to some extent. Therefore, it is a first object of the present disclosure to propose a drive system of an electric car, which can ensure that the engine is always operating on the curve of optimum economy, thus the error-free gear change of the electric car can be realized and the ride comfort can be improved.

A second object of the present disclosure is to propose an electric car.

In order to achieve the above objects, according to a first aspect of embodiments of the present disclosure, there is provided a drive system of an electric car, comprising: a drive battery; an engine and a first clutch connected to the engine; an input shaft, a first output shaft and a second output shaft; a main reduction gear and a second clutch, wherein the main reduction gear is connected to the first clutch via the input shaft; a front wheel drive subsystem having a first motor / generator and a first planetary gear, wherein the first motor / generator is connected to the drive battery and the first planetary gear is connected to the first motor / generator, the first output shaft and the second clutch; a rear wheel drive subsystem having a second motor / generator and a second planetary gear, wherein the second motor / generator is connected to the drive battery and the second planetary gear is connected to the second motor / generator, the second output shaft and the second clutch; and a control unit configured to control the engine, the first motor / generator and the second motor / generator according to an operation mode of the electric car.

With the drive system of an electric car according to embodiments of the present disclosure, various modes can be realized, and the continuously variable transmission can be realized, the engine always operates on the optimum economy curve, so that the faultless gear change for the electric car can be realized, and thus the ride comfort is improved. Due to the high mechanical efficiency of the drive system, the ratio between the brake return of the front axle and that of the rear axle can be adjusted according to the road conditions, so that the brake energy recirculation at the front and rear wheels can be performed by both motor / generators, thus, the stability of the Brake energy feedback and the efficiency of the brake feedback improved.

According to an embodiment of the present disclosure, the control unit is configured to: drive the first motor / generator to start and drive the second motor / generator and the engine to stop if the electric car is in a purely electric front-wheel drive mode; to drive the second motor / generator to start and to drive the first motor / generator and the engine to stop, if the electric car is in a mode of purely electric rear-wheel drive; and the first motor / generator and the second motor / generator for starting to control and the engine to stop if the electric car is in a mode of pure electric real-time four-wheel drive.

According to one embodiment of the present disclosure, the control unit is configured to: drive the first motor / generator to receive braking energy if the electric car is in a front wheel brake energy recirculation mode; to drive the second motor / generator to receive the braking energy if the electric car is in a rear-wheel brake energy recirculation mode; and drive the first motor / generator and the second motor / generator to receive the braking energy if the electric car is in a four-wheel braking energy feedback mode.

According to one embodiment of the present disclosure, the control unit is configured to: drive the first motor / generator and the engine to start and drive the second motor / generator to stop if the electric car is in a front-wheel drive mode; to drive the second motor / generator and the engine to start and to drive the first motor / generator to stop, if the electric car is in a mode of rear-wheel drive hybrid; and to drive the first motor / generator, the second motor / generator and the engine to start if the electric car is in a mode of real-time four-wheel drive hybrid.

According to an embodiment of the present disclosure, the control unit is configured to: drive the first motor / generator to generate electricity if the electric car is in a front-wheel hybrid power generation mode; to drive the second motor / generator to generate electricity if the electric car is in a rear-wheel hybrid power generation mode; and drive the first motor / generator and the second motor / generator to generate electricity if the electric car is in a real-time four-wheel hybrid power generation mode.

According to an embodiment of the present disclosure, if the electric car is in an electric drive mode, the control unit is configured to drive the first motor / generator to operate at maximum torque and the second motor / generator to operate at a difference of expected torque and to drive the maximum torque of the first motor / generator, if the expected torque is greater than the maximum torque of the first motor / generator; and drive the first motor / generator to operate with the expected torque if the expected torque is less than or equal to the maximum torque of the first motor / generator.

According to an embodiment of the present disclosure, if the electric car is in a brake energy recirculation mode, the control unit is configured to: drive the first motor / generator to brake with a negative maximum torque and the second motor / generator to brake with a sum of an expected one To control the torque and the maximum torque of the first motor / generator, if the expected torque is less than or equal to the negative maximum torque of the first motor / generator; and drive the first motor / generator to brake with the expected torque if the expected torque is greater than the negative maximum torque of the first motor / generator.

According to an embodiment of the present disclosure, if the electric car is in a hybrid drive mode, the control unit is configured to allocate torque in an order in which a torque is assigned to the engine, a torque is assigned to the first motor / generator, and Torque is assigned to the second motor / generator.

According to an embodiment of the present disclosure, if the electric car is in a hybrid propulsion mode, the control unit is configured to: drive the first motor / generator, the engine, and the second motor / generator to operate at respective maximum torques if an expected torque is greater than a sum of a maximum torque of the first motor / generator, a maximum torque of the engine and a maximum torque of the second motor / generator; to drive the first motor / generator and the engine to operate at respective maximum torques and to drive the second motor / generator to operate at a value obtained by subtracting the maximum torque of the first motor / generator from a difference of the expected torque and the maximum torque of the first motor / generator first engine / generator is obtained if the expected torque is less than or equal to the sum of the maximum torque of the first motor / generator, the maximum torque of the engine and the maximum torque of the second motor / generator and greater than or equal to a sum the maximum torque of the first motor / generator and the maximum torque of the engine is; the engine to work with her to drive maximum torque and to drive the first motor / generator to operate on the difference between the expected torque and the maximum torque of the engine, if the expected torque is less than the sum of the maximum torque of the first motor / generator and the maximum torque of the engine and larger as the maximum torque of the engine is; and drive the engine to operate with the expected torque if the expected torque is less than the maximum torque of the engine.

According to an embodiment of the present disclosure, if the electric car is in a hybrid power generation mode, the controller is configured to: drive the engine to operate with an expected torque if the expected torque is greater than an engine's economic torque; to control the engine to operate on the economic torque and to drive the first motor / generator to operate with a difference of the expected torque and the economic torque, if the expected torque is less than or equal to the economic torque of the engine and greater than a difference of economic torque and a maximum torque of the first motor / generator is; to drive the engine to operate on the economic torque, to drive the first motor / generator to operate with a negative maximum torque and to drive the second motor / generator to operate at a value obtained by adding the difference of the expected torque and the economic torque to the maximum torque of the first motor / generator is obtained if the expected torque is greater than or equal to the difference of the economic torque and the maximum torque of the first motor / generator and greater than a value obtained by subtracting a sum of the maximum torque of first motor / generator and the maximum torque of the second motor / generator is obtained from the economic torque; and drive the engine to operate at a sum of the expected torque, the maximum torque of the first motor / generator, and the maximum torque of the second motor / generator and to drive the first motor / generator and the second motor / generator to operate at respective negative maximum torques if the expected torque is less than or equal to the value obtained by subtracting a sum of the maximum torque of the first motor / generator and the maximum torque of the second motor / generator from the economic torque of the engine.

In order to achieve the above objects, according to a second aspect of embodiments of the present disclosure, there is provided an electric car having the drive system of an electric car according to the first aspect of embodiments.

With the electric car according to the present disclosure, since it has the drive system, different modes can be realized, and the continuously variable transmission can be realized; the engine always works on the curve of optimal economy, so that the error-free gear change for the electric car can be realized and thus the ride comfort is improved. In addition, due to the high mechanical efficiency of the drive system, the ratio between the brake return of the front axle and that of the rear axle can be adjusted according to the road conditions, so that the brake energy feedback at the front and rear wheels can be performed by both motor / generators, thus providing stability the brake energy return and the efficiency of the brake feedback improved.

BRIEF DESCRIPTION OF THE DRAWINGS

1 FIG. 10 is a block diagram showing the drive system of an electric car according to an embodiment of the present disclosure; FIG.

2 FIG. 10 is a schematic diagram showing the energy flow in the all-electric drive mode according to an embodiment of the present disclosure; FIG.

3 FIG. 10 is a schematic diagram showing the assignment of torques in the all-electric drive mode according to an embodiment of the present disclosure; FIG.

4 FIG. 10 is a schematic diagram showing the energy flow in the brake energy return mode according to an embodiment of the present disclosure; FIG.

5 FIG. 10 is a schematic diagram showing the assignment of torques in the brake energy return mode according to an embodiment of the present disclosure; FIG.

6 is a schematic representation of the energy flow in the Hybrid propulsion mode according to an embodiment of the present disclosure shows;

7 FIG. 10 is a schematic diagram showing the assignment of torques in the hybrid drive mode according to an embodiment of the present disclosure; FIG.

8th FIG. 10 is a schematic diagram showing energy flow in the hybrid power generation mode according to an embodiment of the present disclosure; FIG.

9 FIG. 12 is a schematic diagram showing the assignment of torques in the hybrid power generation mode according to an embodiment of the present disclosure. FIG.

DETAILED DESCRIPTION

Reference will be made in detail to embodiments of the present disclosure wherein the same or similar elements and the elements having the same or similar functions are denoted by like reference characters throughout the descriptions. The embodiments described herein with reference to the drawings are illustrative and illustrative and are used to provide a general understanding of the present disclosure. The embodiments may not be construed as limiting the present disclosure.

The drive system of an electric car and the electric car according to embodiments of the present disclosure will now be described with reference to drawings.

1 FIG. 10 is a block diagram showing the drive system of an electric car according to an embodiment of the present disclosure. FIG. As in 1 illustrated, the drive system of an electric car on: a drive battery (not shown); an engine 15 and a first clutch 14 that with the engine 15 connected is; an input shaft 13 , a first output shaft 11 and a second output shaft 12 ; a main reduction gear (a main reduction gear pinion 5 and a main reduction gear 6 having) and a second clutch 16 wherein the main reduction gear with the first clutch 14 over the input shaft 13 connected is; a front wheel drive subsystem having a first motor / generator 3 and a first planetary gear (a first sun gear 4 , a left planet carrier 2 and a left ring gear 1 having), wherein the first planetary gear with the first motor / generator 3 , the first output shaft 11 and the second clutch 16 connected and the first motor / generator 3 connected to the drive battery; a rear wheel drive subsystem that includes a second motor / generator 9 and a second planetary gear (a second sun gear 10 , a right planet carrier 8th and a right ring gear 7 having), wherein the second planetary gear with the second motor / generator 9 , the second output shaft 12 and the second clutch 16 is connected and the second motor / generator 9 connected to the drive battery; and a control unit (not shown) configured for the engine 15 , the first motor / generator 3 and the second motor / generator 9 to control according to an operating mode of the electric car. The second clutch 16 is an electromagnetic clutch.

In particular, as in 1 represented, the first sun wheel 4 and the second sun wheel 10 firmly connected, the left ring gear 1 is with the first output shaft 11 connected, the left planet carrier 2 is with the first motor / generator 3 connected, and the first output shaft 11 transfers the force to the front drive axle to drive the front wheels; the right ring gear 7 is with the second output shaft 12 connected, the right planet carrier 8th is with the first motor / generator 9 connected, the second output shaft 12 transfers power to the rear drive axle to drive the rear wheels. The second clutch 16 is fixedly connected to the frame of the automobile, and the loosening and fixed connection of the main reduction gear 6 and the frame of the automobile can be performed by the second clutch 16 is activated for disengagement and engagement. Because the first sun wheel 4 and the second sun wheel 10 are firmly connected all the time to ensure that the rotational speed of the front wheels is the same as that of the rear wheels, it is necessary, the rotational speed of the first motor / generator 3 (MG1) and that of the second motor / generator 9 (MG2) to be the same all the time. The allocation of energy of the first output shaft 11 and the second output shaft 12 in real time, by adjusting the output torques of the first motor / generator 3 (MG1) and the second motor / generator 9 (MG2). The continuously variable transmission can be adjusted by adjusting the output rotational speed of the first motor / generator 3 (MG1) and the output rotation speed of the second motor / generator 9 (MG2) be realized, so that the engine 15 can adapt to the entire speed range within the scope of the available rotational speed.

According to embodiments of the present disclosure, the drive system of an electric car may operate in the following modes: a purely electric drive mode (ie, an electric drive mode), a hybrid drive mode, and a brake energy return mode. In the purely electric drive mode, there is a mode of operation of the pure electric front-wheel drive, an all-electric rear-wheel drive mode, and an all-electric real-time four-wheel drive mode; in the hybrid propulsion mode, there is a front-wheel hybrid propulsion mode, a rear-wheel hybrid propulsion mode, and a real-time four-wheel hybrid propulsion mode; and in the brake energy return mode there is a front wheel brake energy feedback mode, a rear brake energy feedback mode, and a real time four-wheel brake energy feedback mode.

Hereinafter, the all-electric drive mode and the torque allocation in the all-electric drive mode will be described in detail.

According to an embodiment of the present disclosure, if the electric car is in the all-electric front-wheel drive mode, the control unit controls the first engine / generator to start, and drives the second motor / generator and the engine to stop; if the electric car is in the all-electric rear-wheel drive mode, the control unit drives the second motor / generator to start and drives the first motor / generator and the engine to stop; if the electric car is in the all-electric four-wheel drive mode, the control unit drives the first motor / generator and the second motor / generator to start and drives the engine to stop.

In particular, in the purely electric drive mode, by the second clutch 16 is driven to engage and the main reduction gear 6 and the frame of the automobile, at this time the main reduction gear 6 do not rotate so that a left planetary gear (ie, the first planetary gear) and a right planetary gear (ie, the second planetary gear) are independent without affecting each other. In this case, if only the first motor / generator 3 (MG1) is involved in the drive and the second motor / generator 9 (MG2) is not involved in the drive and MG2 along with the right planet carrier 8th idling, realized the pure electric front-wheel drive; if only the second motor / generator 9 (MG2) is involved in the drive and the first motor / generator 3 (MG1) is not involved in the drive and MG1 together with the left planet carrier 2 idling, the purely electric rear-wheel drive can be realized; if both the first motor / generator 3 (MG1) and the second motor / generator 9 (MG2) are involved in the drive, the pure electric real-time four-wheel drive can be realized. Therefore, the situation that the front wheels and the rear wheels are involved in driving can be adjusted in accordance with various road information in real time. 2 is a schematic representation showing the energy flow in the pure electric drive mode.

3 FIG. 12 is a schematic diagram showing the assignment of torques in the all-electric drive mode, where T _Req denotes the current expected torque of the wheel end, T _Eng the from the control unit to the engine 15 T _M1 indicates the torque signal sent from the control unit to MG1, T _M2 denotes the torque signal sent from the control unit to MG2, T _Emax the maximum torque of the engine 15 T _{M1max denotes} the maximum torque of MG1 and T _{M2max denotes} the maximum torque of MG2; The above-mentioned torque denotes the torque map from the engine 15 or the motor / generator (the first motor / generator 3 , the second motor / generator 9 ) on the wheel end.

According to one embodiment of the present disclosure, as shown in FIG 3 shown when the electric car is in the electric drive mode (ie, the pure electric drive mode), if the expected torque is greater than the maximum torque of the first motor / generator 3 (MG1) is the first motor / generator 3 (MG1) to operate with the maximum torque, and the second motor / generator 9 (MG2) is used to work with the difference between the expected torque and the maximum torque of the first motor / generator 3 controlled, ie T _M1 = T _M1max , T _M2 = T _Req - T _M1max , T _Eng = 0; if the expected torque is less than or equal to the maximum torque of the first motor / generator 3 (MG1) becomes the first motor / generator 3 to operate with the expected torque, ie T _M1 = T _Req , T _M2 = 0, T _Eng = 0.

In the following, the brake energy return mode and the torque allocation in the brake energy return mode will be described in detail.

According to an embodiment of the present disclosure, if the electric car is in the front wheel brake energy recirculation mode, the control unit controls the first motor / generator 3 for receiving the braking energy; if the electric car is in the rear wheel brake energy recirculation mode, the control unit controls the second motor / generator 9 for receiving the braking energy; and; if the electric car is in the four-wheel brake energy recirculation mode, the control unit controls the first motor / generator 3 and the second motor / generator 9 for receiving the braking energy.

In particular, in the brake energy recirculation mode, the second clutch 16 is driven to engage and the main reduction gear 6 and the frame of the automobile, at this time the main reduction gear 6 do not rotate so that the left planetary gear and the right planetary gear are independent without affecting each other. In this case, if only MG1 is involved in the brake feedback and MG2 is not involved in the brake feedback and MG2 together with the right planet carrier 8th idling, the front wheel brake energy feedback realized; if only MG2 is involved in the brake feedback and MG1 is not involved in the brake feedback and MG1 together with the left planet carrier 2 idling, the rear wheel brake energy recirculation can be realized; if both MG1 and MG2 are involved in the brake feedback, the four-wheel brake energy recirculation can be realized. Therefore, the situation that the front wheels and the rear wheels are involved in the brake feedback may be adjusted in accordance with various road information in real time to achieve the optimum control of the brake energy feedback. 4 is a schematic representation showing the energy flow in the brake energy return mode.

5 Figure 11 is a schematic diagram showing the assignment of torques in the brake energy return mode, where T _Req denotes the current expected wheel end torque, T _Eng, from the control unit to the engine 15 T _M1 indicates the torque signal sent from the control unit to MG1, T _M2 denotes the torque signal sent from the control unit to MG2, T _Emax the maximum torque of the engine 15 T _{M1max denotes} the maximum torque of MG1 and T _{M2max denotes} the maximum torque of MG2; The above-mentioned torque denotes the torque map from the engine 15 or the motor / generator (the first motor / generator 3 , the second motor / generator 9 ) on the wheel end.

According to one embodiment of the present disclosure, as shown in FIG 5 illustrated when the electric car is in the brake energy recirculation mode and if the expected torque (the expected torque T _Req is a negative value in the brake energy recirculation mode) is less than or equal to the negative maximum torque of the first motor / generator 3 (MG1) is the first motor / generator 3 (MG1) to operate with the negative maximum torque, and the second motor / generator 9 (MG2) is used to work with the sum of the expected torque and the maximum torque of the first motor / generator 3 controlled, ie T _M1 = T _M1max , T _M2 = T _Req - T _M1max , T _Eng = 0; if the expected torque is greater than the negative maximum torque of the first motor / generator 3 (MG1) becomes the first motor / generator 3 to operate with the expected torque, ie T _M1 = T _Req , T _M2 = 0, T _Eng = 0.

Hereinafter, the hybrid mode and the assignment of torque in the hybrid mode will be described in detail, and the hybrid mode may be divided into the hybrid drive mode and the hybrid power generation mode.

First, the hybrid drive mode is presented. According to an embodiment of the present disclosure, if the electric car is in the front-wheel drive mode, the control unit controls the first motor / generator 3 and the engine 15 to start and controls the second motor / generator 9 to stop; if the electric car is in the rear-wheel hybrid drive mode, the control unit controls the second motor / generator 9 and the engine 15 to start and controls the first motor / generator 3 to stop; and if the electric car is in the four-wheel drive hybrid mode, the control unit controls the first motor / generator 3 , the second motor / generator 9 and the engine 15 to start.

In particular, in the hybrid propulsion mode, the second clutch 16 is driven to disengage, the main reduction gear 6 and the frame of the automobile disconnected, the main reduction gearbox 6 can rotate with the first sun gear and the second sun gear, and the energy of the engine 15 can over the first clutch 14 , the main reduction gear, the left planetary gear and the right planetary gear are transmitted to the front drive axle and the rear drive axle. Here, if only MG1 is involved in the drive and MG2 is not working, the mode of the front wheel hybrid drive can be realized; if only MG2 is involved in the drive and MG1 is not working, the mode of rear-wheel hybrid drive can be realized; if both MG1 and MG2 are involved in the drive, the mode of the four-wheel hybrid drive can be realized. By adjusting the rotational speeds of MG1 and MG2, the speed ratio between the ring gear and the sun gear can be changed in real time to realize the function of a continuously variable transmission, and the transmission devices can be omitted. In addition, the optimum control of the operating point of the engine can be realized, whereby the fuel consumption is effectively reduced. In this mode, the situation that the front wheels and the rear wheels are involved in the drive can be adjusted according to different road information in real time. 6 is a schematic diagram showing the energy flow in the hybrid drive mode.

7 FIG. 12 is a schematic diagram showing the assignment of torques in the hybrid drive mode, where T _Req denotes the current expected torque of the wheel end, T _Eng the from the control unit to the engine 15 T _M1 indicates the torque signal sent from the control unit to MG1, T _M2 denotes the torque signal sent from the control unit to MG2, T _Emax the maximum torque of the engine 15 T _{M1max denotes} the maximum torque of MG1 and T _{M2max denotes} the maximum torque of MG2; the above-mentioned torque represents the torque map from the engine 15 or the motor / generator (the first motor / generator 3 , the second motor / generator 9 ) on the wheel end.

According to an embodiment of the present disclosure, as shown in FIG 7 that is, if the electric car is in the hybrid drive mode, the control unit is configured to allocate torque in an order in which a torque of the engine 15 is assigned a torque to the first motor / generator 3 is assigned and a torque to the second motor / generator 9 is assigned. More specifically, if the electric car is in the hybrid propulsion mode, it is first judged whether T _Req <= T _M1max + T _Emax + T _M2max ; if not, the torque is assigned according to the following formulas: T _M1 = T _M1max , T _M2 = T _M2max , T _Eng = T _Emax ; if yes, it is judged whether T _Req <T _M1max + T _Emax ; if not, the torque is assigned according to the following formulas: T _M1 = T _M1max , T _M2 = T _Req - T _Emax - T _M1max , T _Eng = T _Emax ; if yes, it is judged whether T _Req <T _Emax ; if yes, the torque is assigned according to the following formulas: T _M1 = 0, T _M2 = 0, T _Eng = T _Req ; if not, the torque is assigned according to the following formulas: T _M1 = T _Req - T _Emax , T _M2 = 0, T _Eng = T _Emax .

Now, the hybrid power generation mode will be presented. According to an embodiment of the present disclosure, if the electric car is in the front-wheel hybrid power generation mode, the control unit controls the first motor / generator 3 for generating electricity; if the electric car is in the rear-wheel hybrid power generation mode, the control unit controls the second motor / generator 9 for generating electricity; and if the electric car is in the four-wheel hybrid power generation mode, the control unit controls the first motor / generator 3 and the second motor / generator 9 for generating electricity.

In particular, in the hybrid power generation mode, the second clutch 16 is driven to disengage, the main reduction gear 6 and the frame of the automobile disconnected, the main reduction gearbox 6 can rotate with the first sun gear and the second sun gear, and the energy of the engine 15 can over the first clutch 14 , the main reduction gear, the left planetary gear and the right planetary gear are transmitted to the front drive axle and the rear drive axle. Here, if only MG1 generates electricity and MG2 does not generate electricity, the mode of front-wheel hybrid power generation can be realized; if only MG2 generates electricity and MG1 does not generate electricity, the mode of rear-wheel hybrid power generation can be realized; if both MG1 and MG2 generate electricity, the mode of four-wheel hybrid power generation can be realized. By adjusting the rotational speeds of MG1 and MG2, the speed ratio between the ring gear and the sun gear can be changed in real time to realize the function of a continuously variable transmission, and the gear devices can be eliminated. In addition, the optimum control of the operating point of the engine can be realized, whereby the fuel consumption is effectively reduced. In this mode, the situation that the front wheels and the rear wheels are involved in the generation of electricity can be adjusted in accordance with different road information in real time. 8th Fig. 10 is a schematic diagram showing the energy flow in the hybrid power generation mode.

9 FIG. 12 is a schematic diagram showing the assignment of torques in the hybrid power generation mode, where T _Req denotes the current expected wheel end torque, T _Eng, from the control unit to the engine 15 T _M1 indicates the torque signal sent from the control unit to MG1, T _M2 denotes the torque signal sent from the control unit to MG2, T _Emax the maximum torque of the engine 15 T _{M1max denotes} the maximum torque of MG1, T _{M2max denotes} the maximum torque of MG2, and T _Engeco the economic torque of the engine 15 designated; the above-mentioned torque denotes the torque map from the engine 15 or the motor / generator (the first motor / generator 3 , the second motor / generator 9 ) on the wheel end.

According to one embodiment of the present disclosure, as shown in FIG 9 illustrated when the electric car is in the hybrid power generation mode, if the expected torque is greater than the economic torque of the engine 15 is, the engine 15 activated to work with the economic torque, ie T _Eng = T _Req , T _M1 = 0, T _M2 = 0; if the expected torque is less than or equal to the economic torque of the engine 15 is greater than a difference of the economic torque and the maximum torque of the first motor / generator 3 is, becomes the engine 15 driven to work with the economic torque, and the first motor / generator 3 is driven to _operate with the difference in expected torque and economic torque, ie T _Eng = T _Engeco , T _M1 = T _Req - T _Engeco , T _M2 = 0; if the expected torque is less than or equal to the difference of the economic torque and the maximum torque of the first motor / generator 3 is greater than the value obtained by subtracting a sum of the maximum torque of the first motor / generator 3 and the maximum torque of the second motor / generator 9 is obtained from the economic torque, the engine 15 driven to work with the economic torque, the first motor / generator 3 is driven to work with the negative maximum torque, and the second motor / generator 9 is driven to operate with the value obtained by adding the maximum torque of the first motor / generator 3 is obtained at the difference of the expected torque and the economic torque, ie T _Eng = T _Engeco , T _M1 = - T _M1max , T _M2 = T _Req - T _Engeco + T _M1max ; if the expected torque is less than or equal to the value obtained by subtracting the sum of the maximum torque of the first motor / generator 3 and the maximum torque of the second motor / generator 9 from the economic torque of the engine 15 will receive the engine 15 to work with the sum of the expected torque, the maximum torque of the first motor / generator 3 and the maximum torque of the second motor / generator 9 driven, and the first motor / generator 3 and the second motor / generator 9 are driven to work with respective negative maximum torques, ie T _Eng = T _Req + T _M1max + T _M2max , T _M1 = -T _M1max , T _M2 = -T _M2max .

In the real-time four-wheel drive solution in related technologies, a transmission is required so that the acceleration of the vehicle and the highest speed can be realized by shifting the transmission, but the function of a continuously variable transmission can not be realized. It is difficult to operate the engine for a long time in the range of high efficiency, which is unfavorable in terms of optimizing the operating point of the engine. In addition, the power transmission efficiency of the system and the efficiency of braking energy feedback in the all-electric mode are low, and the timely adjustment of the ratio between the brake feedback of the front axle and that of the rear axle can not be realized according to the road conditions. In the drive system of an electric car according to the present disclosure, the mechanical efficiency of the power transmission is higher than in the conventional four-wheel drive mode because there is no transmission, which helps to reduce the fuel consumption of the automobile.

With the drive system of an electric car according to embodiments of the present disclosure, various modes can be realized, and the continuously variable transmission can be realized, the engine always operates on the optimum economy curve, so that the faultless gear change for the electric car can be realized, and thus the ride comfort is improved. Due to the high mechanical efficiency of the drive system, the ratio between the brake return of the front axle and that of the rear axle can be adjusted according to the road conditions, so that the brake energy recirculation at the front and rear wheels can be performed by both motor / generators, thus, the stability of the Brake energy feedback and the efficiency of the brake feedback improved.

According to the above embodiments, in the present disclosure, an electric car is proposed which has the drive system of an electric car in the above embodiment.

With the electric car according to the present disclosure, since it has the drive system, various modes can be realized, and the continuously variable transmission can be realized, the engine always works on the optimum economy curve, so that the error-free gear change for the electric car can be realized and thus the ride comfort is improved. In addition, due to the high mechanical efficiency of the drive system, the ratio between the brake return of the front axle and that of the rear axle can be adjusted according to the road conditions, so that the brake energy feedback at the front and rear wheels can be performed by both motor / generators, thus providing stability the brake energy return and the efficiency of the brake feedback improved.

In order to realize the above embodiment, the present disclosure also proposes a control method of an electric car.

Reference herein to "one embodiment", "some embodiments", "a specific example" or "some examples" anywhere in this specification means that a particular feature, structure, material or property associated with the embodiment or described in the example may be present in at least one embodiment or an example of the present disclosure. Thus, the use of these formulations in various places throughout this description does not necessarily refer to the same embodiment or example of the present disclosure. Further, the particular features, structures, materials, or properties may be combined in one or more embodiments or examples in any manner. In addition, those skilled in the art will appreciate that they can combine the embodiments or examples or various features of the various embodiments so long as they do not conflict with each other.

Furthermore, terms such as "first (s)" and "second (s)" are used herein for purposes of description and are not intended to indicate or imply relative importance or meaning, or the number of identified technical features to call. Thus, the "first (r / s)" and "second (r / s)" defined feature may include one or more of these features. In the description of the present disclosure, "several" means two or more than two unless otherwise specified.

The inventive idea of the present disclosure is a connection between the various modules and hardware devices. It does not require changes in the internal structure of the various parts. It can be realized without software support. Even if the particular application requires appropriate software, it will also be used to coordinate with other parts in specific scenarios to better realize the application of the present disclosure, and it has nothing to do with the inventive idea of the present disclosure. Here, if the existing chips are used to work with software, the software and the processing method belong to the existing software and the existing method. The practical effects and purposes do not depend on software, but are achieved by improving the hardware configuration to achieve the object of the invention, and the scope of the present disclosure does not include the software itself, but only the connection between the various parts. Although illustrative embodiments have been illustrated and described, it is to be understood that the above embodiments are illustrative and can not be construed as limiting the present disclosure, and those skilled in the art may make changes, alternatives, and modifications to the embodiments without departing from the scope of the present invention To leave revelation.

Claims (11)

A drive system of an electric car, comprising: a drive battery; an engine and a first clutch connected to the engine; an input shaft, a first output shaft and a second output shaft; a main reduction gear and a second clutch, wherein the main reduction gear is connected to the first clutch via the input shaft; a front wheel drive subsystem comprising a first motor / generator and a first planetary gear, the first motor / generator connected to the drive battery and the first planetary gear connected to the first motor / generator, the first output shaft and the second clutch; a rear wheel drive subsystem comprising a second motor / generator and a second planetary gear, the second motor / generator connected to the drive battery and the second planetary gear connected to the second motor / generator, the second output shaft and the second clutch; and a control unit adapted to the engine, to control the first motor / generator and the second motor / generator according to an operating mode of the electric car. A drive system according to claim 1, wherein the control unit is adapted to to drive the first motor / generator to start and to drive the second motor / generator and the engine to stop, if the electric car is in a mode of pure electric front-wheel drive; to drive the second motor / generator to start and to drive the first motor / generator and the engine to stop, if the electric car is in a mode of purely electric rear-wheel drive; and to control the first motor / generator and the second motor / generator to start and to drive the engine to stop, if the electric car is in a mode of pure real-time four-wheel drive. A drive system according to claim 1, wherein the control unit is adapted to drive the first motor / generator to receive braking energy if the electric car is in a front wheel brake energy recirculation mode; to drive the second motor / generator to receive the braking energy if the electric car is in a rear-wheel brake energy recirculation mode; and to drive the first motor / generator and the second motor / generator to receive the braking energy if the electric car is in a four-wheel braking energy recirculation mode. A drive system according to claim 1, wherein the control unit is adapted to drive the first motor / generator and the engine to start and drive the second motor / generator to stop if the electric car is in a mode of the front-wheel drive hybrid; to drive the second motor / generator and the engine to start and to drive the first motor / generator to stop, if the electric car is in a mode of rear-wheel drive hybrid; and to control the first motor / generator, the second motor / generator and the engine to start if the electric car is in a mode of real-time four-wheel hybrid drive. A drive system according to claim 1, wherein the control unit is adapted to to drive the first motor / generator to generate electricity if the electric car is in a front-wheel hybrid power generation mode; to drive the second motor / generator to generate electricity if the electric car is in a rear-wheel hybrid power generation mode; and to drive the first motor / generator and the second motor / generator to generate electricity if the electric car is in a mode of real-time four-wheel hybrid power generation. Drive system according to claim 1, wherein, if the electric car is in an electric drive mode, the control unit is designed to to drive the first motor / generator to operate at a maximum torque and to drive the second motor / generator to operate with an expected torque difference and the first motor / generator maximum torque if the expected torque is greater than the maximum torque of the first motor / Generator is; and to drive the first motor / generator to operate with the expected torque if the expected torque is less than or equal to the maximum torque of the first motor / generator. Drive system according to claim 1, wherein, if the electric car is in a braking energy return mode, the control unit is designed to to drive the first motor / generator to brake with a negative maximum torque and to drive the second motor / generator for braking with a sum of an expected torque and the maximum torque of the first motor / generator if the expected torque is less than or equal to the negative maximum Torque of the first motor / generator is; and to drive the first motor / generator to brake with the expected torque if the expected torque is greater than the negative maximum torque of the first motor / generator. Drive system according to claim 1, wherein, if the electric car is in a hybrid drive mode, the control unit is adapted to assign torque in an order in which a torque of the engine is assigned, a torque is assigned to the first motor / generator and a Torque is assigned to the second motor / generator. Drive system according to claim 1, wherein, if the electric car is in a hybrid drive mode, the control unit is adapted to drive the first motor / generator, the engine and the second motor / generator to operate with respective maximum torque, if an expected torque is greater than a sum of a maximum torque of the first motor / generator, a maximum torque of the engine and a maximum torque of the second motor / generator; to drive the first motor / generator and the engine to operate at respective maximum torques and to drive the second motor / generator to operate at a value obtained by subtracting the maximum torque of the first motor / generator from a difference of the expected torque and the maximum torque Engine is obtained if the expected torque is less than or equal to the sum of the maximum torque of the first motor / generator, the maximum torque of the engine and the maximum torque is the second motor / generator and is greater than or equal to a sum of the maximum torque of the first motor / generator and the maximum torque of the engine; to drive the engine to operate with the maximum torque of the engine and to drive the first motor / generator to work with the difference of the expected torque and the maximum torque of the engine, if the expected torque is less than the sum of the maximum torque of the first motor / generator and is the maximum torque of the engine and greater than the maximum torque of the engine; and drive the engine to operate with the expected torque if the expected torque is less than the maximum torque of the engine. Drive system according to claim 1, wherein, if the electric car is in a hybrid power generation mode, the control unit is designed to drive the engine to operate with an expected torque if the expected torque is greater than an engine's economic torque; to control the engine to operate on the economic torque and to drive the first motor / generator to operate with a difference of the expected torque and the economic torque, if the expected torque is less than or equal to the economic torque of the engine and greater than a difference of economic torque and a maximum torque of the first motor / generator is; to drive the engine to operate on the economic torque, to drive the first motor / generator to operate with a negative maximum torque and to drive the second motor / generator to operate at a value obtained by adding the difference of the expected torque and the economic torque to the maximum torque of the first motor / generator is obtained if the expected torque is greater than or equal to the difference of the economic torque and the maximum torque of the first motor / generator and greater than a value obtained by subtracting a sum of the maximum torque of the first motor / generator and the maximum torque of the second motor / generator is obtained from the economic torque; and to drive the engine to operate at a sum of the expected torque, the maximum torque of the first motor / generator, and the maximum torque of the second motor / generator and to drive the first motor / generator and the second motor / generator to operate at respective negative maximum torques; if the expected torque is less than or equal to the value obtained by subtracting the sum of the maximum torque of the first motor / generator and the maximum torque of the second motor / generator from the economic torque of the engine. An electric car comprising the drive system of an electric car according to any one of claims 1-10.

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