Hybrid power driving system, vehicle and driving system control method

Abstract

The invention relates to a hybrid power driving system, a vehicle and a driving system control method. The hybrid power driving system comprises an engine, a first motor, a first connection and disconnection device, a planetary gear mechanism, a second motor, a first shaft, a second shaft, an intermediate shaft, an intermediate shaft gear, a main reduction driving gear, a main reduction driven gear, a motor driving gear, a parking gear and a differential mechanism. The vehicle can be parked by locking the parking gear; the planetary gear mechanism comprises a sun gear, a planet gear, a planet carrier and a gear ring, the first shaft is connected between a rotor of the first motor and the sun gear, the engine is connected with the planet carrier, and a gear ring outer gear meshed with the intermediate shaft gear is arranged on the gear ring; the first connecting and disconnecting device is connected between the sun gear and the static component and used for selectively connecting or disconnecting the sun gear and the static component. According to the hybrid power driving system, EPB abrasion can be reduced, and therefore the potential safety hazards of vehicle braking are eliminated.

Description

Technical Field

[0001] The present invention belongs to the technical field of hybrid power, and in particular relates to a hybrid power drive system, a vehicle and a drive system control method. Background Art

[0002] At present, the drive systems of hybrid vehicles mainly include three basic forms: series, parallel and hybrid. In the series drive system, there is no mechanical connection between the engine and the output shaft, which can achieve optimized control of speed / torque, but all its energy needs to be converted between mechanical power / electric power twice before it can be transferred to the output shaft, resulting in large energy losses. The parallel drive system has high transmission efficiency, but the mechanical connection between the engine and the output shaft cannot ensure that the engine is always in the optimal working area, and is usually used for medium and high speed conditions of the vehicle. The hybrid drive system combines the advantages of series and parallel, and can achieve both optimized control of the engine and efficient control of medium and high speed conditions.

[0003] The hybrid is divided into series-parallel hybrid and power split hybrid. Among the power split hybrid, the single-stage input power split structure is the simplest and most widely used. Toyota, for example, began to use it in large quantities in automobiles in 1997.

[0004] However, the existing power split hybrid system has the following problems: In parking mode / parking mode, the drive motor needs to twist the generator to generate electricity, which consumes energy and is very easy to get stuck, causing the drive motor to overheat and demagnetize and fail. In addition, the forced parking power generation function requires frequent activation of the EPB (Electrical Park Brake), which will accelerate the wear of the EPB and cause potential safety hazards to vehicle braking. Summary of the invention

[0005] The technical problem to be solved by the present invention is: for the existing power-split hybrid system, in the parking mode / stopping mode, the drive motor needs to twist the generator to generate electricity, the drive motor consumes energy and is very likely to be blocked, causing the drive motor to overheat and demagnetize and fail. A hybrid drive system, a vehicle and a drive system control method are provided.

[0006] To solve the above technical problems, on the one hand, an embodiment of the present invention provides a hybrid power drive system, including an engine, a first motor, a first engagement and disengagement device, a planetary gear mechanism, a second motor, a first shaft, a second shaft, an intermediate shaft, an intermediate shaft gear, a main reduction driving gear, a main reduction driven gear, a motor drive gear, a parking gear and a differential; the intermediate shaft gear and the main reduction driving gear are arranged on the intermediate shaft, the main reduction driven gear is arranged on the housing of the differential and meshed with the main reduction driving gear, the motor drive gear and the parking gear are arranged on the second shaft, the motor drive gear is meshed with the intermediate shaft gear, and one end of the second shaft is connected to the rotor of the second motor; the vehicle can be parked by locking the parking gear;

[0007] The planetary gear mechanism includes a sun gear, planetary gears, a planetary carrier and a ring gear, the first shaft is connected between the rotor of the first motor and the sun gear, the engine is connected to the planetary carrier, and the ring gear is provided with a ring gear outer gear meshing with the intermediate shaft gear;

[0008] The first engaging and disengaging device is connected between the sun gear and the stationary component, and is used for selectively engaging or disengaging the sun gear and the stationary component.

[0009] On the other hand, an embodiment of the present invention further provides a vehicle, which includes the above-mentioned hybrid power drive system.

[0010] In the hybrid drive system and vehicle of the embodiment of the present invention, the motor drive gear and the parking gear are arranged on the second shaft connected to the rotor of the second motor, and the motor drive gear is meshed with the intermediate shaft gear arranged on the intermediate shaft, and the vehicle can be parked by locking the parking gear. In this way, since the motor drive gear is connected to the rotor of the second motor, and the intermediate shaft gear meshed with the motor drive gear is arranged on the intermediate shaft, by means of the large speed ratio of the gear pair composed of the motor drive gear and the intermediate shaft gear, when the vehicle is parked or stopped, only a small torque is required to lock the vehicle, so that parking power generation and parking power generation can be achieved without energy consumption, and the second motor (drive motor) does not need to twist the first motor (generator) to generate power, which can avoid the second motor consuming energy and causing the second motor to be blocked and cause overheating and demagnetization failure, and can also avoid the problem of frequent starting of EPB to force the parking power generation function, which can reduce EPB wear, thereby eliminating the potential safety hazards of vehicle braking.

[0011] On the other hand, an embodiment of the present invention further provides a drive system control method, which is based on the above hybrid drive system, and the method includes:

[0012] Establishing a hierarchical distribution model of the working modes of the hybrid power drive system; wherein the hybrid power drive system has at least a pure electric drive mode, a power split mode, a parallel hybrid mode and an engine direct drive mode;

[0013] Switching among the pure electric drive mode, power split mode, parallel hybrid mode and engine direct drive mode is performed according to the operating mode hierarchical distribution model. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a simplified structural diagram of a hybrid power drive system provided by a first embodiment of the present invention;

[0015] Figure 2 is a simplified structural diagram of a hybrid power drive system provided by a second embodiment of the present invention;

[0016] Figure 3 is a framework diagram of a drive system control method provided by a third embodiment of the present invention;

[0017] Figure 4 is a state control requirement diagram of a battery SOC of a drive system control method provided by a third embodiment of the present invention;

[0018] Figure 5 is a hierarchical distribution model diagram of the working modes of the drive system control method provided by the third embodiment of the present invention;

[0019] Figure 6 is a first-layer distribution diagram of a hierarchical distribution model of working modes of a driving system control method provided by a third embodiment of the present invention;

[0020] Figure 7 is a second layer distribution diagram of the working mode hierarchical distribution model of the driving system control method provided by the third embodiment of the present invention;

[0021] Figure 8 is a simplified structural diagram of a hybrid power drive system provided by a fourth embodiment of the present invention;

[0022] Fig. 9 is a hierarchical distribution model diagram of the working modes of the driving system control method provided by the fifth embodiment of the present invention;

[0023] Fig.10 is a first-layer distribution diagram of a hierarchical distribution model of working modes of a driving system control method provided by a fifth embodiment of the present invention;

[0024] Fig.11 is a second layer distribution diagram of the working mode hierarchical distribution model of the driving system control method provided by the fifth embodiment of the present invention;

[0025] Fig.12It is the third layer distribution diagram of the working mode hierarchical distribution model of the driving system control method provided in the fifth embodiment of the present invention.

[0026] The reference numerals in the specification are as follows:

[0027] 1. Engine; 2. First motor; 3. First engaging and disconnecting device; 4. Planetary gear mechanism; 41. Sun gear; 42. Planetary gear; 43. Planet carrier; 44. Ring gear; 5. Second motor; 6. First shaft; 61. First shaft section; 62. Second shaft section; 7. Second shaft; 8. Intermediate shaft; 9. Intermediate shaft gear; 10. Main reduction driving gear; 20. Main reduction driven gear; 30. Motor drive gear; 40. Parking gear; 50. Differential; 60. Ring gear outer gear; 70. Second engaging and disconnecting device; 80. Second engaging and disconnecting device. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] A hybrid drive system provided by an embodiment of the present invention comprises an engine, a first motor, a first engaging and disengaging device, a planetary gear mechanism, a second motor, a first shaft, a second shaft, an intermediate shaft, an intermediate shaft gear, a main reduction driving gear, a main reduction driven gear, a motor drive gear, a parking gear and a differential; the intermediate shaft gear and the main reduction driving gear are arranged on the intermediate shaft, the main reduction driven gear is arranged on the housing of the differential and meshes with the main reduction driving gear, the motor drive gear and the parking gear are arranged on the second shaft, the motor drive gear meshes with the intermediate shaft gear, and one end of the second shaft is connected to the rotor of the second motor; the vehicle can be parked by locking the parking gear; the planetary gear mechanism comprises a sun gear, a planetary gear, a planetary carrier and a ring gear, the first shaft is connected between the rotor of the first motor and the sun gear, the engine is connected to the planetary carrier, and the ring gear is provided with a ring gear outer gear meshed with the intermediate shaft gear; the first engaging and disengaging device is connected between the sun gear and a stationary component, and is used to selectively engage or disconnect the sun gear and the stationary component.

[0030] In some embodiments, the stationary component is a housing of the first electric machine.

[0031] In other embodiments, the stationary component is a housing of a planetary gear mechanism.

[0032] In other embodiments, the stationary component may also be other relatively stationary components on the vehicle body.

[0033] In some embodiments, the first shaft, the second shaft and the intermediate shaft are arranged parallel to each other and spaced apart from each other, so that the axial length of the hybrid power drive system can be shortened, which is beneficial to the layout of the whole vehicle.

[0034] In some embodiments, the first motor and the engine are located on both sides of the first shaft, and the second motor and the first motor are located on the same side of the first shaft. In this way, the engine and the two motors are located on both sides of the hybrid drive system, respectively, which is more compact, and the two motors are on the same side, which is conducive to the layout of the motor controller and reduces the length of the motor harness.

[0035] In some embodiments, the first motor, the first engagement and disengagement device, the planetary gear mechanism and the engine are arranged in sequence along the axial direction of the first shaft. In this way, the structure is compact and is conducive to the layout of the whole vehicle.

[0036] In some embodiments, the second motor, the motor drive gear and the parking gear are arranged in sequence along the axial direction of the second shaft. In this way, the structure is compact and is conducive to the layout of the whole vehicle.

[0037] In some embodiments, the diameter of the motor drive gear is smaller than the diameter of the intermediate shaft gear; the diameter of the ring gear outer gear is smaller than the diameter of the intermediate shaft gear. That is, the diameter of the intermediate shaft gear is larger than the diameter of the motor drive gear and the ring gear outer gear. In this way, the output power of the second motor is reduced through the motor drive gear and the intermediate shaft gear, and the power output of the ring gear is reduced through the ring gear outer gear and the intermediate shaft gear.

[0038] In some embodiments, the first end of the first engagement and disconnection device is connected to the stationary component, and the second end of the first engagement and disconnection device is connected to the first shaft, so that the first engagement and disconnection device is located between the stationary component and the first shaft as a whole, and the first engagement and disconnection device is arranged more compactly and does not occupy too much space.

[0039] One of the first end and the second end of the first engaging and disengaging device is an active end (an end pushed by the actuator), and the other is a driven end.

[0040] In some embodiments, the hybrid drive system further includes a damping element connected between the engine and the planet carrier, wherein the damping element is a single-mass flywheel, a dual-mass flywheel, a torsional damper or a hydraulic torque converter. The damping element can absorb the vibration of the engine and improve the driving experience.

[0041] In some embodiments, the first engaging / disengaging device is a clutch, a synchronizer, or a brake.

[0042] In some embodiments, the clutch is a wet multi-plate clutch, which is more reliable than a dry clutch.

[0043] In some embodiments, the hybrid drive system has a pure electric drive mode, a power split mode, a parallel hybrid mode, an engine direct drive mode and a parking power generation mode; the first engagement and disconnection device is disconnected, the second motor is driven, the engine and the first motor do not work, and the hybrid drive system enters the pure electric drive mode; the first engagement and disconnection device is disconnected, the engine drives the first motor to generate electricity while driving the first motor, and the electric energy generated by the first motor is fully or partially provided to the second motor, the second motor drives, and the hybrid drive system enters the power split mode; the first engagement and disconnection device is engaged, the engine drives, the second motor drives or generates electricity, the first motor does not work, and the hybrid drive system enters the parallel hybrid mode; the first engagement and disconnection device is engaged, the engine drives, the first motor does not work, the second motor idles, and the hybrid drive system enters the engine direct drive mode; when the vehicle is parked, the parking gear is locked, the first engagement and disconnection device is disconnected, the second motor does not work, the engine drives the first motor to generate electricity, and the hybrid drive system enters the parking power generation mode.

[0044] By controlling the working state of the engine, the first motor and the second motor, and selectively engaging or disengaging the first engaging and disengaging device, multiple driving modes such as pure electric driving mode, power split mode, parallel hybrid mode, engine direct drive mode and parking power generation mode can be realized. Input power split is the optimal hybrid configuration for single-stage power split, and input power split is most efficient especially in the medium and low speed range. If the battery is not sufficient after pure electric starting, the input power split mode can be switched.

[0045] In some embodiments, the parallel hybrid mode includes a parallel assist mode and a parallel power generation mode; when the first engagement / disengagement device is engaged, the engine is driven, the second motor is driven, the first motor is not working, and the hybrid drive system enters the parallel assist mode; when the first engagement / disengagement device is engaged, the engine is driven, the second motor is powered, the first motor is not working, and the hybrid drive system enters the parallel power generation mode.

[0046] In some embodiments, the hybrid drive system has a braking energy recovery mode in pure electric drive mode, a braking energy recovery mode in power split mode, a braking energy recovery mode in parallel hybrid mode, and a braking energy recovery mode in engine direct drive mode; when the vehicle is braked in the pure electric drive mode, the first engagement and disengagement device is disengaged, the second motor is subjected to reverse torque to decelerate and generate electricity, the engine and the first motor do not work, and the hybrid drive system enters the braking energy recovery mode in pure electric drive mode; when the vehicle is braked in the power split mode, the first engagement and disengagement device is disengaged, the second motor is subjected to reverse torque to decelerate and generate electricity, the engine drives and drives the first motor to generate electricity, and the hybrid drive system enters the braking energy recovery mode in power split mode; when the vehicle is braked in the parallel hybrid mode, the first engagement and disengagement device is engaged, the second motor is subjected to reverse torque to decelerate and generate electricity, the engine drives, the first motor does not work, and the hybrid drive system enters the braking energy recovery mode in parallel hybrid mode; when the vehicle is braked in the engine direct drive mode, the first engagement and disengagement device is engaged, the second motor is subjected to reverse torque to decelerate and generate electricity, the engine drives, the first motor does not work, and the hybrid drive system enters the braking energy recovery mode in engine direct drive mode.

[0047] In this way, each driving mode has a corresponding braking energy recovery mode, and the second motor can be used to achieve efficient braking energy recovery. In another embodiment, a second engaging and disengaging device is further included, the first shaft includes a first shaft section and a second shaft section that are coaxial and spaced from each other, a first end of the first engaging and disengaging device is connected to the stationary component, one end of the first shaft section is connected to the rotor of the first motor, the second engaging and disengaging device is connected between the other end of the first shaft section and the second end of the first engaging and disengaging device, and the second shaft section is connected between the second end of the first engaging and disengaging device and the sun gear.

[0048] The engagement and disconnection of the second engagement and disconnection device can realize the power connection and disconnection between the first motor and the sun gear. In this way, the second motor starts purely electric, and by disconnecting the second engagement and disconnection device, the first motor is disconnected from the sun gear, so that the load of the sun gear is 0. In the pure electric driving mode, the second motor is prevented from reversely dragging the engine and the first motor, which improves the system working efficiency and increases the cruising range of electric vehicles (especially PHEV models).

[0049] The freedom of the ring gear can be eliminated by the twisting action of the second motor and the parking gear. The second engagement and disengagement device can be selectively engaged, and the engine can be quickly restarted by the first motor.

[0050] In an embodiment with a first engagement and disconnection device and a second engagement and disconnection device, the hybrid drive system has a pure electric drive mode, a power split mode, a parallel hybrid mode, an engine direct drive mode and a parking power generation mode; the first engagement and disconnection device is disconnected, the second engagement and disconnection device is disconnected, the second motor is driven, the engine and the first motor do not work, and the hybrid drive system enters a pure electric drive mode; the first engagement and disconnection device is disconnected, the second engagement and disconnection device is engaged, the engine drives and drives the first motor to generate electricity at the same time, the electric energy generated by the first motor is fully or partially provided to the second motor, the second motor drives, and the hybrid drive system enters a power split mode. flow mode; the first engagement and disconnecting device is engaged, the second engagement and disconnecting device is disconnected, the engine is driven, the second motor is driven or generates electricity, the first motor does not work, and the hybrid drive system enters a parallel hybrid mode; the first engagement and disconnecting device is engaged, the second engagement and disconnecting device is disconnected, the engine is driven, the first motor does not work, the second motor is idling, and the hybrid drive system enters an engine direct drive mode; when the vehicle is parked, the parking gear is locked, the first engagement and disconnecting device is disconnected, the second engagement and disconnecting device is engaged, the second motor does not work, the engine drives the first motor to generate electricity, and the hybrid drive system enters a parking power generation mode.

[0051] In an embodiment having a first engagement and disconnection device and a second engagement and disconnection device, the parallel hybrid mode includes a parallel assist mode and a parallel power generation mode; the first engagement and disconnection device is engaged, the second engagement and disconnection device is disengaged, the engine is driven, the second motor is driven, the first motor is not working, and the hybrid drive system enters a parallel assist mode; the first engagement and disconnection device is engaged, the second engagement and disconnection device is disengaged, the engine is driven, the second motor is driven, the first motor is not working, and the hybrid drive system enters a parallel power generation mode.

[0052] In an embodiment having a first engagement and disconnection device and a second engagement and disconnection device, the hybrid drive system has a braking energy recovery mode in a pure electric drive mode, a braking energy recovery mode in a power split mode, a braking energy recovery mode in a parallel hybrid mode, and a braking energy recovery mode in an engine direct drive mode; when the vehicle brakes in the pure electric drive mode, the first engagement and disconnection device is disconnected, the second engagement and disconnection device is disconnected, the second motor is subjected to reverse torque to decelerate and generate electricity, the engine and the first motor do not work, and the hybrid drive system enters a braking energy recovery mode in the pure electric drive mode; when the vehicle brakes in the power split mode, the first engagement and disconnection device is disconnected, the second engagement and disconnection device is engaged, the second motor is subjected to reverse torque to decelerate and generate electricity , the engine drives the first motor to generate electricity while driving it, and the hybrid drive system enters the braking energy recovery mode under the power split mode; when the vehicle brakes in the parallel hybrid mode, the first engagement and disengagement device is engaged, the second engagement and disengagement device is disengaged, the second motor is decelerated by the reverse torque to generate electricity, the engine is driven, the first motor does not work, and the hybrid drive system enters the braking energy recovery mode under the parallel hybrid mode; when the vehicle brakes in the engine direct drive mode, the first engagement and disengagement device is engaged, the second engagement and disengagement device is disengaged, the second motor is decelerated by the reverse torque to generate electricity, the engine is driven, the first motor does not work, and the hybrid drive system enters the braking energy recovery mode under the engine direct drive mode.

[0053] In some embodiments, a third engaging and disconnecting device is further included, wherein the third engaging and disconnecting device is connected between the second end of the first engaging and disconnecting device and the planet carrier. In this embodiment, the second engaging and disconnecting device is not included.

[0054] In an embodiment with a first engagement and disconnection device and a third engagement and disconnection device, the hybrid power drive system has a pure electric drive mode, a power split mode, a parallel hybrid 1st gear mode, a parallel hybrid 2nd gear mode, an engine direct drive 1st gear mode, an engine direct drive 2nd gear mode and a parking power generation mode; the first engagement and disconnection device is disconnected, the third engagement and disconnection device is disconnected, the second motor is driven, the engine and the first motor do not work, and the hybrid power drive system enters a pure electric drive mode; the first engagement and disconnection device is disconnected, the third engagement and disconnection device is disconnected, the engine drives while driving the first motor to generate electricity, and the electric energy generated by the first motor is fully or partially provided to the second motor, the second motor drives, and the hybrid power drive system enters a power split mode; the first engagement and disconnection device is disconnected, the third engagement and disconnection device is engaged, the engine drives, the second motor drives or generates electricity, the first motor drives, generates electricity or idles, and the hybrid The power drive system enters the parallel hybrid 1st gear mode; the first engagement and disconnection device is engaged, the third engagement and disconnection device is disconnected, the engine is driven, the second motor is driven or generates electricity, the first motor does not work, and the hybrid drive system enters the parallel hybrid 2nd gear mode; the first engagement and disconnection device is disconnected, the third engagement and disconnection device is engaged, the engine is driven, the first motor is idling, the second motor is idling, and the hybrid drive system enters the engine direct drive 1st gear mode; the first engagement and disconnection device is engaged, the third engagement and disconnection device is disconnected, the engine is driven, the first motor does not work, the second motor is idling, and the hybrid drive system enters the engine direct drive 2nd gear mode; when the vehicle is parked, the parking gear is locked, the first engagement and disconnection device is disconnected, the third engagement and disconnection device is disconnected, the second motor does not work, the engine drives the first motor to generate electricity, and the hybrid drive system enters the parking power generation mode.

[0055] In an embodiment with a first engagement and disconnection device and a third engagement and disconnection device, the parallel hybrid mode includes a parallel 1st gear power-assisting mode, a parallel 1st gear power-generating mode, a parallel 2nd gear power-assisting mode and a parallel 2nd gear power-generating mode; the first engagement and disconnection device is disconnected, the third engagement and disconnection device is engaged, the engine is driven, the second motor is driven, the first motor is driven, generates power or idles, and the hybrid drive system enters the parallel 1st gear power-assisting mode; the first engagement and disconnection device is disconnected, the third engagement and disconnection device is engaged, the engine is driven, the second motor generates power, the first motor is driven, generates power or idles, and the hybrid drive system enters the parallel 1st gear power-generating mode; the first engagement and disconnection device is engaged, the third engagement and disconnection device is disconnected, the engine is driven, the second motor is driven, the first motor does not work, and the hybrid drive system enters the parallel 2nd gear power-assisting mode; the first engagement and disconnection device is engaged, the third engagement and disconnection device is disconnected, the engine is driven, the second motor is driven, the first motor does not work, and the hybrid drive system enters the parallel 2nd gear power-generating mode.

[0056] In an embodiment with a first engagement and disconnection device and a third engagement and disconnection device, the hybrid drive system has a braking energy recovery mode in a pure electric drive mode, a braking energy recovery mode in a power split mode, a braking energy recovery mode in a parallel hybrid 1st gear mode, a braking energy recovery mode in a parallel hybrid 2nd gear mode, a braking energy recovery mode in an engine direct drive 1st gear mode, and a braking energy recovery mode in an engine direct drive 2nd gear mode; when the vehicle brakes in the pure electric drive mode, the first engagement and disconnection device is disconnected, the third engagement and disconnection device is disconnected, the second motor is subjected to reverse torque to decelerate and generate electricity, the engine and the first motor do not work, and the hybrid drive system enters a braking energy recovery mode in a pure electric drive mode; when the vehicle brakes in the power split mode, the first engagement and disconnection device is disconnected, the third engagement and disconnection device is disconnected, the second motor is subjected to reverse torque to decelerate and generate electricity, the engine drives and drives the first motor to generate electricity at the same time, and the hybrid drive system enters a braking energy recovery mode in a power split mode; when the vehicle brakes in the parallel hybrid 1st gear mode, the first engagement and disconnection device is disconnected, the third engagement and disconnection device is engaged, the generator The motor is driven, the second motor is decelerated by the reverse torque to generate electricity, the first motor is driven, generates electricity or idles, and the hybrid drive system enters the braking energy recovery mode under the parallel hybrid 1st gear mode; when the vehicle is braked in the parallel hybrid 2nd gear mode, the first engagement and disconnection device is engaged, the third engagement and disconnection device is disconnected, the engine is driven, the second motor is decelerated by the reverse torque to generate electricity, the first motor does not work, and the hybrid drive system enters the braking energy recovery mode under the parallel hybrid 2nd gear mode; when the vehicle is braked in the engine direct drive 1st gear mode, the first engagement and disconnection device is disconnected, the third engagement and disconnection device is engaged, the engine is driven, the second motor is decelerated by the reverse torque to generate electricity, the first motor generates electricity or idles, and the hybrid drive system enters the braking energy recovery mode under the engine direct drive 1st gear mode; when the vehicle is braked in the engine direct drive 2nd gear mode, the first engagement and disconnection device is engaged, the third engagement and disconnection device is disconnected, the engine is driven, the second motor is decelerated by the reverse torque to generate electricity, the first motor does not work, and the hybrid drive system enters the braking energy recovery mode under the engine direct drive 2nd gear mode.

[0057] In the embodiment with the first engaging and disengaging device and the third engaging and disengaging device, by controlling the working state of the engine, the first motor and the second motor, and selectively engaging or disengaging the first engaging and disengaging device and the second engaging and disengaging device, multiple driving modes such as pure electric driving mode, power split mode, parallel hybrid 1st gear mode, parallel hybrid 2nd gear mode, engine direct drive 1st gear mode, engine direct drive 2nd gear mode and parking power generation mode can be realized. Moreover, in the mode where the engine participates in driving, the engine can have two 2 gears, so that the hybrid power driving system of this embodiment can be suitable for urban conditions and small and medium-sized vehicles, and can take into account the power and economy of the whole vehicle.

[0058] In the hybrid drive system of the embodiment of the present invention, the motor drive gear and the parking gear are arranged on the second shaft connected to the rotor of the second motor, and the motor drive gear is meshed with the intermediate shaft gear arranged on the intermediate shaft, and the vehicle can be parked by locking the parking gear. In this way, since the motor drive gear is connected to the rotor of the second motor, and the intermediate shaft gear meshed with the motor drive gear is arranged on the intermediate shaft, by means of the large speed ratio of the gear pair composed of the motor drive gear and the intermediate shaft gear, when the vehicle is parked or stopped, only a small torque is required to lock the vehicle, so that parking power generation and parking power generation can be achieved without energy consumption, and the second motor (drive motor) does not need to twist the first motor (generator) to generate power, which can avoid the second motor consuming energy and causing the second motor to be blocked and cause overheating and demagnetization failure, and can also avoid the problem of frequent starting of EPB to force the parking power generation function, which can reduce EPB wear, thereby eliminating the potential safety hazards of vehicle braking.

[0059] In addition, during the mode switching process, the second motor can participate in the driving, there is no power interruption, and the driving experience is better.

[0060] In addition, the first motor can increase speed and torque through the planetary gear mechanism, which can effectively reduce the size of the first motor.

[0061] In addition, the hybrid drive system can cover HEV and PHEV models, with good platformization.

[0062] In addition, the hybrid drive system has a corresponding brake energy recovery mode in each drive mode, and can use the second motor to achieve efficient brake energy recovery. The brake energy recovery covers all driving conditions, has high energy recovery efficiency, and can improve vehicle endurance.

[0063] The following combination Figures 1 to 12 A hybrid power drive system and a drive system control method provided by an embodiment of the present invention are described in detail.

[0064] First embodiment

[0065] like Figure 1As shown, the hybrid driving system provided by the first embodiment of the present invention includes an engine 1, a first motor 2, a first engaging and disengaging device 3, a planetary gear mechanism 4, a second motor 5, a first shaft 6, a second shaft 7, an intermediate shaft 8, an intermediate shaft gear 9, a main reduction driving gear 10, a main reduction driven gear 20, a motor driving gear 30, a parking gear 40 and a differential 50. The two ends of the differential 20 are respectively connected to the first half shaft and the second half shaft, the outer end of the first half shaft is connected to the first wheel, and the outer end of the second half shaft is connected to the second wheel. One of the first wheel and the second wheel is a left wheel, and the other is a right wheel.

[0066] The intermediate shaft gear 9 and the main reduction driving gear 10 are arranged on the intermediate shaft 9, the intermediate shaft gear 9 is fixed (for example, splined) on the intermediate shaft 8 or formed integrally on the intermediate shaft 8, and the main reduction driving gear 10 is fixed (for example, splined) on the intermediate shaft 8 or formed integrally on the intermediate shaft 8.

[0067] The main reduction driven gear 20 is disposed on the housing of the differential 50 and meshes with the main reduction driving gear 10 . The main reduction driven gear 20 is fixed (eg, splined) or integrally formed on the housing of the differential 50 .

[0068] The motor drive gear 30 and the parking gear 40 are arranged on the second shaft 7, the motor drive gear 30 is meshed with the intermediate shaft gear 9, and the motor drive gear 30 and the parking gear 40 are fixed (e.g., splined) on the second shaft 7 or integrally formed on the second shaft 7. One end of the second shaft 7 is connected to the rotor of the second motor 5; the vehicle can be parked by locking the parking gear 40, for example, by engaging the parking pawl in the parking gear 40 to park the vehicle.

[0069] The planetary gear mechanism 4 includes a sun gear 41, a planetary gear 42, a planetary carrier 43 and a ring gear 44. The first shaft 6 is connected between the rotor of the first motor 2 and the sun gear 41. The engine 1 is connected to the planetary carrier 43. The ring gear 44 is provided with a ring gear outer gear 60 meshing with the intermediate shaft gear 9. The ring gear outer gear 60 is fixed (e.g., splined) on the ring gear 44 or formed integrally on the ring gear 44. The first engagement and disengagement device 3 is connected between the sun gear 41 and the stationary component, and is used to selectively engage or disengage the sun gear 41 and the stationary component. The first shaft 6, the second shaft 7 and the intermediate shaft 8 are arranged parallel to each other and spaced apart. In this way, the axial length of the hybrid drive system can be shortened, which is beneficial to the layout of the entire vehicle.

[0070] The first motor 2 and the engine 1 are located on both sides of the first shaft 6, and the second motor 5 and the first motor 2 are located on the same side of the first shaft 6. In this way, the engine 1 and the two motors are located on both sides of the hybrid drive system, respectively, and the arrangement is more compact. In addition, the two motors are located on the same side, which is conducive to the arrangement of the motor controller and reduces the length of the motor harness.

[0071] The first motor 2, the first engaging and disengaging device 3, the planetary gear mechanism 4 and the engine 1 are arranged in sequence along the axial direction of the first shaft 6. In this way, the structure is compact and is conducive to the layout of the whole vehicle.

[0072] The second motor 5, the motor drive gear 30 and the parking gear 40 are arranged in sequence along the axial direction of the second shaft 7. In this way, the structure is compact and is conducive to the layout of the whole vehicle.

[0073] The diameter of the motor drive gear 30 is smaller than the diameter of the intermediate shaft gear 9; the diameter of the ring gear external gear 60 is smaller than the diameter of the intermediate shaft gear 9. That is, the diameter of the intermediate shaft gear 9 is larger than the diameters of the motor drive gear 30 and the ring gear external gear 60. In this way, the output power of the second motor 5 is reduced through the motor drive gear 30 and the intermediate shaft gear 9, and the power output of the ring gear 44 is reduced through the ring gear external gear 60 and the intermediate shaft gear 9.

[0074] The first end of the first engaging and disengaging device 3 is connected to the stationary component, and the second end of the first engaging and disengaging device 3 is connected to the first shaft 6. The first engaging and disengaging device 3 is located as a whole between the stationary component and the first shaft 6, and the first engaging and disengaging device 3 is arranged more compactly and does not occupy too much space. One of the first end and the second end of the first engaging and disengaging device 3 is an active end (an end pushed by an actuator), and the other is a driven end.

[0075] In this embodiment, the first engaging and disengaging device 3 is a brake.

[0076] However, in other embodiments, clutches, synchronizers, or other elements with similar functions may be used instead of brakes.

[0077] When the first engagement and disengagement device 3 is engaged, the first shaft 6, the first motor 2 and the sun gear 41 are all braked, and the power of the engine 1 can be input through the planetary carrier 43 and output through the ring gear 44. When the first engagement and disengagement device 3 is disengaged, the first motor 2 is connected to the sun gear 41 through the first shaft 6. The first motor 2 can generate electricity under the drive of the engine 1, or it can be driven together with the engine 1.

[0078] The hybrid drive system may further include a damping element connected between the engine 1 and the planet carrier 43 , wherein the damping element is a single-mass flywheel, a dual-mass flywheel, a torsional damper or a hydraulic torque converter.

[0079] In the hybrid drive system of the first embodiment of the present invention, since the motor drive gear 30 is connected to the rotor of the second motor 5, and the intermediate shaft gear 9 meshing with the motor drive gear 30 is arranged on the intermediate shaft 8, by means of the large speed ratio of the gear pair composed of the motor drive gear 30 and the intermediate shaft gear 9, when the vehicle is parked or stopped, only a very small torque is required to lock the vehicle, so that parking power generation and parking power generation can be achieved without energy consumption, and the second motor 5 (drive motor) is not required to twist the first motor 2 (generator) to generate electricity, which can avoid the second motor 5 consuming energy and causing overheating and demagnetization failure caused by stalling, and can also avoid the problem of frequent starting of EPB to forcibly achieve the parking power generation function, which can reduce EPB wear and eliminate vehicle braking safety hazards.

[0080] The hybrid drive system of the first embodiment of the present invention can realize multiple drive modes such as pure electric drive mode, power split mode, parallel hybrid mode, engine direct drive mode and parking power generation mode by controlling the working states of the engine 1, the first motor 2 and the second motor 5, and selectively engaging or disconnecting the first engaging and disconnecting device 3.

[0081] In addition, each driving mode has a corresponding braking energy recovery mode, and the second motor can be used to achieve efficient braking energy recovery. During the mode switching process, the second motor 5 can participate in the drive, there is no power interruption, and the driving experience is better. The first motor 2 can increase speed and torque through the planetary gear mechanism 4, which can effectively reduce the volume of the first motor 2. The hybrid drive system can cover HEV models and PHEV models, and has a good platform.

[0082] The control under each driving mode is shown in Table 1 below:

[0083] Table 1

[0084]

[0085] In Table 1, “ / ” indicates not working.

[0086] The power transmission in each driving mode is as follows:

[0087] (1) Pure electric driving mode

[0088] The first engagement and disengagement device 3 is disconnected, the second motor 5 is driven, the engine 1 and the first motor 2 are not working, and the hybrid drive system enters the pure electric drive mode. At this time, the power transmission route is: second motor 5-motor drive gear 30-intermediate shaft gear 9-main reduction driving gear 10-main reduction driven gear 20-differential 50. This mode is mainly used for starting and medium and low speed driving of the vehicle.

[0089] (3) Power split mode

[0090] The first engagement and disengagement device 3 is disconnected, and the engine 1 drives the first motor 2 to generate electricity while driving, and the electric energy generated by the first motor 2 is provided in whole or in part to the second motor 5, and the second motor 5 drives, and the hybrid drive system enters the power split mode. At this time, the power transmission route is divided into three routes. The first route is: the second motor 5-motor drive gear 30-intermediate shaft gear 9-main reduction driving gear 10-main reduction driven gear 20-differential 50; the second route is: engine 1-planet carrier 43-planetary gear 42-ring gear 44-ring gear outer gear 60-intermediate shaft gear 9-main reduction driving gear 10-main reduction driven gear 20-differential 50; the third route (power generation path) is: engine 1-planet carrier 43-planetary gear 42-sun gear 41-first motor 2. This mode is mainly used to cover the vehicle's medium and low speed conditions, and also covers the high speed conditions exceeding the mechanical point. When the power is sufficient and the battery pack SOC is not saturated, the power through the first motor 2 can be partially used to charge the battery pack. When the required power is greater than the power of the engine 1, if the battery pack SOC is not low, the insufficient power can also be discharged by the battery and output through the second motor 5.

[0091] (4) Parallel hybrid mode

[0092] The first engagement and disengagement device 3 is engaged, the engine 1 is driven, the second motor 5 is driven or generates electricity, the first motor 2 is not working, and the hybrid drive system enters the parallel hybrid mode. According to the second motor 5 assisting or driving, the parallel hybrid mode can also be divided into a parallel assisting mode and a parallel generating mode. In the parallel assisting mode, the power transmission route is divided into two routes, the first route is: the second motor 5-motor drive gear 30-intermediate shaft gear 9-main reduction driving gear 10-main reduction driven gear 20-differential 50; the second route is: engine 1-planet carrier 43-planetary gear 42-ring gear 44-ring gear outer gear 60-intermediate shaft gear 9-main reduction driving gear 10-main reduction driven gear 20-differential 50. In the parallel power generation mode, the power transmission route is divided into two routes. The first route is: engine 1-planet carrier 43-planetary gear 42-ring gear 44-ring gear outer gear 60-intermediate shaft gear 9-motor drive gear 30-second motor 5; the second route is: engine 1-planet carrier 43-planetary gear 42-ring gear 44-ring gear outer gear 60-intermediate shaft gear 9-main reduction driving gear 10-main reduction driven gear 20-differential 50. The parallel hybrid mode is mainly used for high-speed hybrid driving. Most of the power of the engine 1 is directly used for driving (without electric power conversion), and the first motor 2 can adjust the torque working range of the engine 1 under the premise of meeting the power demand of the whole vehicle, so that the engine 1 can achieve torque decoupling, and the engine 1 is in the optimal torque working range when the battery pack SOC is sufficient, and the system operates efficiently. In the parallel power mode, there are two power sources driving (engine 1 + second motor 5), and the vehicle has good power.

[0093] (5) Engine direct drive mode

[0094] The first engagement and disengagement device 3 is engaged, the engine 1 is driven, the first motor 2 is not working, the second motor 5 is idling, and the hybrid drive system enters the engine direct drive mode. At this time, the power transmission route is: engine 1-planet carrier 43-planetary gear 42-ring gear 44-ring gear outer gear 60-intermediate shaft gear 9-main reduction driving gear 10-main reduction driven gear 20-differential 50. This mode is mainly used for high-speed engine direct drive. In order to avoid the power reflux phenomenon caused by input power diversion, the vehicle speed must be switched to this mode when it approaches the mechanical point; in this mode, the power of the engine 1 is not converted into electric power, but is directly driven, and the system efficiency is high.

[0095] (6) Parking power generation mode

[0096] When the vehicle is parked, the parking gear 40 is locked, the first engagement and disengagement device 3 is disconnected, the second motor 5 does not work, the engine 1 drives the first motor 2 to generate electricity, and the hybrid drive system enters the parking power generation mode. At this time, the power transmission route is: engine 1-planet carrier 43-planetary gear 42-sun gear 41-first motor 2. This mode is mainly used for parking power feeding conditions such as traffic lights.

[0097] (7) Braking energy recovery mode in pure electric driving mode

[0098] When the vehicle brakes in the pure electric drive mode, the first engagement and disengagement device 3 is disconnected, the second motor 5 is decelerated by the reverse torque to generate electricity, the engine 1 and the first motor 2 do not work, and the hybrid drive system enters the braking energy recovery mode in the pure electric drive mode. At this time, the braking energy recovery route is: wheel-differential 50-main reduction driven gear 20-main reduction driving gear 10-intermediate shaft gear 9-motor drive gear 30-second motor 5. This mode is applied to the vehicle braking energy recovery in the pure electric drive mode.

[0099] (8) Braking energy recovery mode in power split mode

[0100] When the vehicle brakes in the power split mode, the first engagement and disengagement device 3 is disconnected, the second motor 5 is decelerated by the reverse torque to generate electricity, the engine 1 drives the first motor 2 to generate electricity, and the hybrid drive system enters the braking energy recovery mode in the power split mode. At this time, the braking energy recovery route is: wheel-differential 50-main reduction driven gear 20-main reduction driving gear 10-intermediate shaft gear 9-motor drive gear 30-second motor 5. This mode is applied to vehicle braking energy recovery in the power split mode.

[0101] (9) Braking energy recovery mode in parallel hybrid mode

[0102] When the vehicle brakes in the parallel hybrid mode, the first engagement and disengagement device 3 is engaged, the second motor 5 is decelerated and generates electricity by the reverse torque, the engine 1 is driven, the first motor 2 is not working, and the hybrid drive system enters the braking energy recovery mode in the parallel hybrid mode. At this time, the braking energy recovery route is: wheel-differential 50-main reduction driven gear 20-main reduction driving gear 10-intermediate shaft gear 9-motor drive gear 30-second motor 5. This mode is applied to the vehicle braking energy recovery in the parallel hybrid mode.

[0103] (10) Braking energy recovery mode in engine direct drive mode

[0104] When the vehicle brakes in the engine direct drive mode, the first engaging and disengaging device 3 is engaged, the second motor 5 is subjected to reverse torque deceleration to generate electricity, the engine 1 is driven, the first motor 2 is not working, and the hybrid drive system enters the braking energy recovery mode in the engine direct drive mode. At this time, the braking energy recovery route is: wheel-differential 50-main reduction driven gear 20-main reduction driving gear 10-intermediate shaft gear 9-motor drive gear 30-second motor 5. This mode is applied to vehicle braking energy recovery in the engine direct drive mode.

[0105] Second embodiment

[0106] Figure 2 The hybrid drive system provided by the second embodiment of the present invention is shown. The difference from the first embodiment is that it also includes a second engagement and disconnection device 70, the first shaft 6 includes a first shaft segment 61 and a second shaft segment 62 that are coaxial and separated from each other, the first end of the first engagement and disconnection device 3 is connected to the stationary component, one end of the first shaft segment 61 is connected to the rotor of the first motor 2, the second engagement and disconnection device 70 is connected between the other end of the first shaft segment 61 and the second end of the first engagement and disconnection device 3, and the second shaft segment 62 is connected between the second end of the first engagement and disconnection device 3 and the sun gear 41.

[0107] The engagement and disconnection of the second engagement and disconnection device 3 can realize the power connection and disconnection between the first motor 2 and the sun gear 41. In this way, in the pure electric driving mode, by disconnecting the second engagement and disconnection device 70, the first motor 2 is disconnected from the sun gear 41, so that the load of the sun gear is 0. In the pure electric driving mode, it is avoided that the second motor 5 reversely drags the engine 1 and the first motor 2, improves the system working efficiency, and increases the cruising range of electric vehicles (especially PHEV models).

[0108] The freedom of the ring gear can be eliminated by the twisting action of the second motor 5 and the parking gear 30. The second engagement and disengagement device 70 can be selectively engaged, and the engine 1 can be quickly restarted by the first motor 2.

[0109] The second engagement and disengagement device 70 is a clutch. Preferably, the clutch is a wet multi-plate clutch. The wet multi-plate clutch is more reliable than a dry clutch.

[0110] However, the second engaging / disengaging device 70 may also be a synchronizer, a brake or other element having similar functions.

[0111] In this embodiment, the hybrid drive system also has a pure electric drive mode, a power split mode, a parallel hybrid mode, an engine direct drive mode and a parking power generation mode. In addition, each drive mode has a corresponding brake energy recovery mode, and the second motor can be used to achieve efficient brake energy recovery.

[0112] The control under each driving mode is shown in Table 2 below:

[0113] Table 2

[0114]

[0115] In Table 2, " / " means not working.

[0116] In the second embodiment, the power (power) transmission under each driving mode is similar to that of the first embodiment.

[0117] The third embodiment

[0118] Refer to Figures 3 to 7 , the embodiment of the present invention also provides a driving system control method, based on the hybrid driving system of the first and second embodiments, the method includes:

[0119] Establish a hierarchical distribution model of the working modes of the hybrid driving system; wherein, the hybrid driving system at least has a pure electric driving mode, a power split mode, a parallel hybrid mode and an engine direct driving mode.

[0120] Switch between the pure electric driving mode, the power split mode, the parallel hybrid mode and the engine direct driving mode according to the hierarchical distribution model of the working modes.

[0121] Refer to Figures 5 to 7 , the hierarchical distribution model of the working modes has two layers. To avoid frequent switching between the two layers, the hierarchical condition between the first layer and the second layer of the hierarchical distribution model of the working modes is V20 < V2; the first layer of the hierarchical distribution model of the working modes distributes the power split mode and the pure electric driving mode, and the second layer of the hierarchical distribution model of the working modes distributes the pure electric driving mode, the parallel hybrid mode and the engine direct driving mode. Among them, V20 represents the first vehicle speed threshold, and V2 represents the second vehicle speed threshold. The vehicle speed thresholds are preset according to experience, and then V20 and V2 are calibrated through later vehicle calibration.

[0122] The state control requirements of the battery pack SOC are as Figure 4 shown. The battery pack SOC should not be too high or too low. It is very important to maintain the relative balance of SOC. The driving system control method of the embodiment of the present invention can maintain the relative balance of SOC, so as to ensure excellent power performance of the vehicle while maintaining high efficiency of the system and thus obtaining excellent fuel economy.

[0123] The method further includes:

[0124] A buffer area is set on the switching path of each working mode, and a buffer area is set on the engine start and stop switching path. A certain buffer area should be set when switching between each working mode and engine start and stop to avoid frequent switching of working modes and frequent starting and stopping of the engine.

[0125] The method further comprises:

[0126] Monitor the SOC of the battery pack in real time.

[0127] When the current SOC of the battery pack is higher than the set upper limit SOCh and the vehicle power demand Pr is lower than the set lower limit Prl, the engine is controlled not to work, so that the battery pack alone provides power to the second motor to drive the vehicle.

[0128] When the current SOC of the battery pack is lower than the set lower limit SOCl, or the current SOC of the battery pack is between the set upper and lower limits SOCh and SOCl and the vehicle demand power Pr is between the set upper and lower limits Prh and Prl, or the vehicle demand power Pr is higher than the set upper limit Prh, the engine is controlled to work so that the engine serves as the main power source to drive the vehicle. At this time, the operating parameters of the first motor and the second motor are calculated according to the determination formula of the operating parameters of each component in the power split mode, so as to determine the operating status of the two motors.

[0129] When the current SOC of the battery pack is higher than the set upper limit SOCh and the vehicle demand power Pr is between the set upper and lower limits Prh and Prl, or the current SOC of the battery pack is between the set upper and lower limits SOCh and SOCl and the vehicle demand power Pr is lower than the set lower limit Prl, in order to avoid frequent switching of working modes and frequent starting and stopping of the engine, a transition zone is set so that the working mode of the hybrid drive system remains in the working mode of the previous moment (referred to as maintaining the previous mode).

[0130] The method further comprises:

[0131] In the power split mode of the hybrid drive system, after the engine is started, when the engine demand power Per is lower than the minimum power value Pemin on the engine minimum fuel consumption line, the engine is controlled to operate at the minimum power value Pemin power point; when the engine demand power Per is higher than the maximum power value Pemax on the engine minimum fuel consumption line, the engine is controlled to operate at the maximum power value Pemax power point; when the engine demand power Per is between the maximum power value Pemax and the minimum power value Pemin on the engine minimum fuel consumption line, the engine is controlled to operate on its minimum fuel consumption line; wherein, the engine demand power Per is equal to the vehicle demand power Pr + loss power + accessory power.

[0132] The method further comprises:

[0133] In the engine direct drive mode or parallel hybrid mode, when the engine demand power Per is lower than the minimum power value Pemin on the engine minimum fuel consumption line, the engine is controlled to operate at the minimum power value Pemin power point; when the engine demand power Per is higher than the maximum power value Pemax on the engine minimum fuel consumption line, the engine is controlled to operate at the maximum power value Pemax power point; when the engine demand power Per is between the maximum power value Pemax and the minimum power value Pemin on the engine minimum fuel consumption line, the engine is controlled to operate on its minimum fuel consumption line Peopt.

[0134] When the engine demand power Per is higher than the engine minimum fuel consumption line Peopt and the current SOC of the battery pack is greater than the set lower limit value SOCl, the hybrid power drive system is switched to the parallel assist mode of the parallel hybrid mode; when the engine demand power Per is lower than the engine minimum fuel consumption line Peopt and the current SOC is less than the set upper limit value SOCh, the hybrid power drive system is switched to the parallel power generation mode of the parallel hybrid mode.

[0135] In the third embodiment, the specific mode switching conditions are shown in Table 3:

[0136] Table 3

[0137]

[0138] Fourth embodiment

[0139] Figure 8 The fourth embodiment of the hybrid driving system provided by the present invention is shown. The fourth embodiment is different from the first embodiment in that it further includes a third engaging and disengaging device 80 . The third engaging and disengaging device 80 is between the second end of the first engaging and disengaging device 3 and the planet carrier 43 .

[0140] The engagement and disengagement of the third engagement and disengagement device 80 can realize the connection and disengagement of the planet carrier 43 and the sun gear 41. When the third engagement and disengagement device 80 is engaged, the planet carrier 43 is connected to the sun gear 41, the planetary gear mechanism 4 rotates as a whole, and the speed ratio of the planetary gear mechanism 4 is 1. When the third engagement and disengagement device 80 is disengaged, the planet carrier 43 is disconnected from the sun gear 41, and the speed ratio of the planetary gear mechanism 4 is not 1.

[0141] In this embodiment, the hybrid power drive system has a pure electric drive mode, a power split mode, a parallel hybrid 1st gear mode, a parallel hybrid 2nd gear mode, an engine direct drive 1st gear mode, an engine direct drive 2nd gear mode and a parking power generation mode.

[0142] The first engaging and disengaging device 3 is disengaged, the third engaging and disengaging device 80 is disengaged, the second motor 5 is driven, the engine 1 and the first motor 2 are not operated, and the hybrid drive system enters a pure electric drive mode.

[0143] The first engagement / disengagement device 3 is disconnected, the third engagement / disengagement device 80 is disconnected, the engine 1 is driven and at the same time drives the first motor 2 to generate electricity, the electric energy generated by the first motor 2 is fully or partially provided to the second motor 5, the second motor 5 is driven, and the hybrid drive system enters a power split mode.

[0144] The first engagement and disconnection device 3 is disconnected, the third engagement and disconnection device 80 is engaged (the planetary gear mechanism 4 rotates as a whole), the engine 1 is driven, the second motor 5 is driven or generates electricity, the first motor 2 is driven, generates electricity or idles, and the hybrid drive system enters the parallel hybrid 1st gear mode. The first engagement and disconnection device 3 is engaged, the third engagement and disconnection device 80 is disconnected, the engine 1 is driven, the second motor 5 is driven or generates electricity, the first motor 2 is not working, and the hybrid drive system enters the parallel hybrid 2nd gear mode.

[0145] The first engagement disconnecting device 3 is disengaged, the third engagement disconnecting device 80 is engaged, the engine 1 is driven, the first motor 2 is idling, the second motor 5 is idling, and the hybrid drive system enters the engine direct drive 1st gear mode. The first engagement disconnecting device 3 is engaged, the third engagement disconnecting device 80 is disengaged, the engine 1 is driven, the first motor 2 is not working, the second motor 5 is idling, and the hybrid drive system enters the engine direct drive 2nd gear mode.

[0146] When the vehicle is parked, the parking gear 30 is locked, the first engaging and disengaging device 3 is disengaged, the third engaging and disengaging device 80 is disengaged, the second motor 5 does not work, the engine 1 drives the first motor 2 to generate electricity, and the hybrid drive system enters the parking power generation mode.

[0147] The parallel hybrid mode includes a parallel 1st gear power-assisting mode, a parallel 1st gear power-generating mode, a parallel 2nd gear power-assisting mode and a parallel 2nd gear power-generating mode; the first engagement and disconnection device 3 is disconnected, the third engagement and disconnection device 80 is engaged, the engine 1 is driven, the second motor 5 is driven, the first motor is driven, generated or idled, and the hybrid drive system enters the parallel 1st gear power-assisting mode; the first engagement and disconnection device 3 is disconnected, the third engagement and disconnection device 80 is engaged, the engine 1 is driven, the second motor 5 is generated, the first motor 2 is driven, generated or idled, and the hybrid drive system enters the parallel 1st gear power-generating mode; the first engagement and disconnection device 3 is engaged, the third engagement and disconnection device 80 is disconnected, the engine 1 is driven, the second motor 5 is driven, the first motor 2 is not working, and the hybrid drive system enters the parallel 2nd gear power-assisting mode; the first engagement and disconnection device 3 is engaged, the third engagement and disconnection device 80 is disconnected, the engine 1 is driven, the second motor 5 is driven, the first motor 2 is not working, and the hybrid drive system enters the parallel 2nd gear power-generating mode.

[0148] The hybrid drive system has a braking energy recovery mode in pure electric drive mode, a braking energy recovery mode in power split mode, a braking energy recovery mode in parallel hybrid 1st gear mode, a braking energy recovery mode in parallel hybrid 2nd gear mode, a braking energy recovery mode in engine direct drive 1st gear mode and a braking energy recovery mode in engine direct drive 2nd gear mode.

[0149] When the vehicle brakes in the pure electric drive mode, the first engagement and disengagement device 3 is disconnected, the third engagement and disengagement device 80 is disconnected, the second motor 5 is decelerated by the reverse torque to generate electricity, the engine 1 and the first motor 2 do not work, and the hybrid drive system enters the braking energy recovery mode in the pure electric drive mode.

[0150] When the vehicle brakes in the power split mode, the first engagement and disengagement device 5 is disconnected, the third engagement and disengagement device 80 is disconnected, the second motor 5 is decelerated by the reverse torque to generate electricity, the engine 1 drives the first motor 2 to generate electricity at the same time, and the hybrid drive system enters the braking energy recovery mode in the power split mode.

[0151] When the vehicle brakes in the parallel hybrid 1st gear mode, the first engagement / disengagement device 3 is disengaged, the third engagement / disengagement device 80 is engaged, the engine 1 is driven, the second motor 5 is decelerated by reverse torque to generate electricity, the first motor 2 is driven, generates electricity or idles, and the hybrid drive system enters the braking energy recovery mode in the parallel hybrid 1st gear mode.

[0152] When the vehicle brakes in the parallel hybrid 2nd gear mode, the first engagement / disengagement device 3 is engaged, the third engagement / disengagement device 80 is disengaged, the engine 1 is driven, the second motor 5 is decelerated by the reverse torque to generate electricity, the first motor 2 does not work, and the hybrid drive system enters the braking energy recovery mode in the parallel hybrid 2nd gear mode.

[0153] When the vehicle brakes in the engine direct drive 1st gear mode, the first engagement and disengagement device 3 is disengaged, the third engagement and disengagement device 80 is engaged, the engine 1 is driven, the second motor 5 is decelerated by the reverse torque to generate electricity, the first motor 2 generates electricity or idles, and the hybrid drive system enters the braking energy recovery mode in the engine direct drive 1st gear mode.

[0154] When the vehicle brakes in the engine direct drive 2nd gear mode, the first engagement and disengagement device 3 is engaged, the third engagement and disengagement device 80 is disengaged, the engine 1 is driven, the second motor 5 is decelerated by the reverse torque to generate electricity, the first motor 2 does not work, and the hybrid drive system enters the braking energy recovery mode in the engine direct drive 2nd gear mode.

[0155] In this embodiment, the control under each driving mode is shown in Table 4 below:

[0156] Table 4

[0157]

[0158]

[0159] In Table 4, “ / ” indicates not working.

[0160] Fifth embodiment

[0161] See also Figures 9 to 12 The fifth embodiment of the present invention further provides a driving system control method, which is based on the hybrid driving system of the fourth embodiment and is different from the driving system control method of the third embodiment in that:

[0162] The hierarchical distribution model of the working modes has three layers. The hierarchical condition between the first layer and the second layer of the hierarchical distribution model of the working modes is V10 < V1, and the hierarchical condition between the second layer and the third layer of the hierarchical distribution model of the working modes is V20 > V2; the parallel hybrid mode includes a parallel hybrid first-gear mode and a parallel hybrid second-gear mode, and the engine direct drive mode includes an engine direct drive first-gear mode and an engine direct drive second-gear mode; the first layer of the hierarchical distribution model of the working modes is distributed with the power split mode and the pure electric drive mode, the second layer of the hierarchical distribution model of the working modes is distributed with the pure electric drive mode, the parallel hybrid first-gear mode and the engine direct drive first-gear mode, and the third layer of the hierarchical distribution model of the working modes is distributed with the pure electric drive mode, the parallel hybrid second-gear mode and the engine direct drive second-gear mode. Among them, V20 represents the first vehicle speed threshold, V2 represents the second vehicle speed threshold, V10 represents the third vehicle speed threshold, and V1 represents the fourth vehicle speed threshold. The vehicle speed thresholds are preset according to experience, and then V20, V10, V1, and V2 are calibrated through subsequent vehicle calibration.

[0163] In addition, an embodiment of the present invention further provides a vehicle, which includes the hybrid drive system of the above embodiment.

[0164] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hybrid power drive system, characterized in that: The invention comprises an engine, a first motor, a first engaging and disengaging device, a planetary gear mechanism, a second motor, a first shaft, a second shaft, an intermediate shaft, an intermediate shaft gear, a main reduction driving gear, a main reduction driven gear, a motor driving gear, a parking gear and a differential; The intermediate shaft gear and the main reduction driving gear are arranged on the intermediate shaft, the main reduction driven gear is arranged on the housing of the differential and meshes with the main reduction driving gear, the motor driving gear and the parking gear are arranged on the second shaft, the motor driving gear meshes with the intermediate shaft gear, and one end of the second shaft is connected to the rotor of the second motor; the vehicle can be parked by locking the parking gear; The planetary gear mechanism includes a sun gear, planetary gears, a planetary carrier and a ring gear, the first shaft is connected between the rotor of the first motor and the sun gear, the engine is connected to the planetary carrier, and the ring gear is provided with a ring gear outer gear meshing with the intermediate shaft gear; The first engaging and disengaging device is connected between the sun gear and the stationary component, and is used for selectively engaging or disengaging the sun gear and the stationary component.

2. The hybrid drive system according to claim 1, characterized in that: The first shaft, the second shaft and the intermediate shaft are arranged parallel to each other and spaced apart.

3. The hybrid drive system according to claim 2, characterized in that: The first motor and the engine are located on both sides of the first shaft in the axial direction, and the second motor and the first motor are located on the same side of the first shaft in the axial direction.

4. The hybrid drive system according to claim 1, characterized in that: The first motor, the first engaging and disengaging device, the planetary gear mechanism and the engine are arranged in sequence along the axial direction of the first shaft.

5. The hybrid drive system according to claim 1, characterized in that: The second motor, the motor driving gear and the parking gear are arranged in sequence along the axial direction of the second shaft.

6. The hybrid drive system according to claim 1, characterized in that: The diameter of the motor drive gear is smaller than the diameter of the intermediate shaft gear; The diameter of the ring gear outer gear is smaller than the diameter of the intermediate shaft gear.

7. The hybrid drive system according to claim 1, characterized in that: A first end of the first engaging and disengaging device is connected to the stationary member, and a second end of the first engaging and disengaging device is connected to the first shaft.

8. The hybrid drive system according to claim 1, characterized in that: The hybrid drive system has a pure electric drive mode, a power split mode, a parallel hybrid mode, an engine direct drive mode and a parking power generation mode; The first engagement and disengagement device is disengaged, the second motor is driven, the engine and the first motor are not operated, and the hybrid drive system enters a pure electric drive mode; The first engagement and disengagement device is disengaged, the engine drives the first motor to generate electricity while the first motor is driven, the electric energy generated by the first motor is fully or partially provided to the second motor, the second motor is driven, and the hybrid drive system enters a power split mode; The first engagement / disengagement device is engaged, the engine is driven, the second motor is driven or generates electricity, the first motor is not operated, and the hybrid drive system enters a parallel hybrid mode; The first engagement disconnecting device is engaged, the engine is driven, the first motor is not operated, the second motor is idle, and the hybrid drive system enters an engine direct drive mode; When the vehicle is parked, the parking gear is locked, the first engaging and disengaging device is disconnected, the second motor does not work, the engine drives the first motor to generate electricity, and the hybrid drive system enters a parking power generation mode.

9. The hybrid drive system according to claim 8, characterized in that: The parallel hybrid mode includes a parallel power-assist mode and a parallel power generation mode; The first engagement and disengagement device is engaged, the engine is driven, the second motor is driven, the first motor is not operated, and the hybrid drive system enters a parallel power-assist mode; The first engaging / disengaging device is engaged, the engine is driven, the second motor is generating electricity, the first motor is not working, and the hybrid drive system enters a parallel generating mode.

10. The hybrid drive system according to claim 8, characterized in that: The hybrid drive system has a braking energy recovery mode in pure electric drive mode, a braking energy recovery mode in power split mode, a braking energy recovery mode in parallel hybrid mode and a braking energy recovery mode in engine direct drive mode; When the vehicle brakes in the pure electric drive mode, the first engagement and disengagement device is disconnected, the second motor is decelerated by the reverse torque to generate electricity, the engine and the first motor do not work, and the hybrid drive system enters the braking energy recovery mode in the pure electric drive mode; When the vehicle brakes in the power split mode, the first engagement and disengagement device is disconnected, the second motor is decelerated by the reverse torque to generate electricity, the engine drives the first motor to generate electricity at the same time, and the hybrid drive system enters the braking energy recovery mode in the power split mode; When the vehicle brakes in the parallel hybrid mode, the first engaging and disengaging device engages, the second motor is decelerated by the reverse torque to generate electricity, the engine drives, the first motor does not work, and the hybrid drive system enters the braking energy recovery mode in the parallel hybrid mode; When the vehicle brakes in the engine direct drive mode, the first engagement and disengagement device engages, the second motor is decelerated by reverse torque to generate electricity, the engine is driven, the first motor does not work, and the hybrid drive system enters the braking energy recovery mode in the engine direct drive mode.

11. The hybrid drive system according to claim 7, characterized in that: It also includes a second engaging and disconnecting device, the first shaft includes a first shaft segment and a second shaft segment that are coaxial and spaced apart from each other, a first end of the first engaging and disconnecting device is connected to the stationary component, one end of the first shaft segment is connected to the rotor of the first motor, the second engaging and disconnecting device is connected between the other end of the first shaft segment and the second end of the first engaging and disconnecting device, and the second shaft segment is connected between the second end of the first engaging and disconnecting device and the sun gear.

12. The hybrid drive system according to claim 11, characterized in that: The hybrid drive system has a pure electric drive mode, a power split mode, a parallel hybrid mode, an engine direct drive mode and a parking power generation mode; The first engaging and disengaging device is disengaged, the second engaging and disengaging device is disengaged, the second motor is driven, the engine and the first motor are not operated, and the hybrid drive system enters a pure electric drive mode; The first engagement and disengagement device is disengaged, the second engagement and disengagement device is engaged, the engine is driven and the first motor is driven to generate electricity, the electric energy generated by the first motor is fully or partially provided to the second motor, the second motor is driven, and the hybrid drive system enters a power split mode; The first engaging and disengaging device is engaged, the second engaging and disengaging device is disengaged, the engine is driven, the second motor is driven or generates electricity, the first motor is not operated, and the hybrid drive system enters a parallel hybrid mode; The first engaging and disengaging device is engaged, the second engaging and disengaging device is disengaged, the engine is driven, the first motor is not operated, the second motor is idling, and the hybrid drive system enters an engine direct drive mode; When the vehicle is parked, the parking gear is locked, the first engaging and disengaging device is disengaged, the second engaging and disengaging device is engaged, the second motor does not work, the engine drives the first motor to generate electricity, and the hybrid drive system enters a parking power generation mode.

13. The hybrid drive system according to claim 12, characterized in that: The parallel hybrid mode includes a parallel power-assist mode and a parallel power generation mode; The first engaging and disengaging device is engaged, the second engaging and disengaging device is disengaged, the engine is driven, the second motor is driven, the first motor is not operated, and the hybrid drive system enters a parallel power-assisting mode; The first engaging / disengaging device is engaged, the second engaging / disengaging device is disengaged, the engine is driven, the second motor generates electricity, the first motor does not work, and the hybrid drive system enters a parallel power generation mode.

14. The hybrid drive system according to claim 12, characterized in that: The hybrid drive system has a braking energy recovery mode in pure electric drive mode, a braking energy recovery mode in power split mode, a braking energy recovery mode in parallel hybrid mode and a braking energy recovery mode in engine direct drive mode; When the vehicle brakes in the pure electric drive mode, the first engaging and disengaging device is disengaged, the second engaging and disengaging device is disengaged, the second motor is decelerated by the reverse torque to generate electricity, the engine and the first motor do not work, and the hybrid drive system enters the braking energy recovery mode in the pure electric drive mode; When the vehicle brakes in the power split mode, the first engaging and disengaging device is disengaged, the second engaging and disengaging device is engaged, the second motor is decelerated by the reverse torque to generate electricity, the engine drives the first motor to generate electricity at the same time, and the hybrid drive system enters the braking energy recovery mode in the power split mode; When the vehicle brakes in the parallel hybrid mode, the first engaging and disengaging device is engaged, the second engaging and disengaging device is disengaged, the second motor is decelerated by the reverse torque to generate electricity, the engine is driven, the first motor is not operated, and the hybrid drive system enters the braking energy recovery mode in the parallel hybrid mode; When the vehicle brakes in the engine direct drive mode, the first engagement and disengagement device engages, the second engagement and disengagement device disengages, the second motor is decelerated by reverse torque to generate electricity, the engine is driven, the first motor does not work, and the hybrid drive system enters the braking energy recovery mode in the engine direct drive mode.

15. The hybrid drive system according to claim 7, characterized in that: A third engaging and disconnecting device is also included, and the third engaging and disconnecting device is connected between the second end of the first engaging and disconnecting device and the planet carrier.

16. The hybrid drive system according to claim 15, characterized in that: The hybrid drive system has a pure electric drive mode, a power split mode, a parallel hybrid 1st gear mode, a parallel hybrid 2nd gear mode, an engine direct drive 1st gear mode, an engine direct drive 2nd gear mode and a parking power generation mode; The first engagement and disengagement device is disengaged, the third engagement and disengagement device is disengaged, the second motor is driven, the engine and the first motor are not operated, and the hybrid drive system enters a pure electric drive mode; The first engagement and disengagement device is disengaged, the third engagement and disengagement device is disengaged, the engine is driven and the first motor is driven to generate electricity, the electric energy generated by the first motor is fully or partially provided to the second motor, the second motor is driven, and the hybrid drive system enters a power split mode; The first engagement and disengagement device is disengaged, the third engagement and disengagement device is engaged, the engine is driven, the second motor is driven or generates electricity, the first motor is driven, generates electricity or idles, and the hybrid drive system enters a parallel hybrid 1st gear mode; The first engaging and disengaging device is engaged, the third engaging and disengaging device is disengaged, the engine is driven, the second motor is driven or generates electricity, the first motor is not operated, and the hybrid drive system enters a parallel hybrid 2nd gear mode; The first engagement and disconnection device is disengaged, the third engagement and disconnection device is engaged, the engine is driven, the first motor is idling, the second motor is idling, and the hybrid drive system enters the engine direct drive 1st gear mode; The first engaging and disengaging device is engaged, the third engaging and disengaging device is disengaged, the engine is driven, the first motor is not operated, the second motor is idling, and the hybrid drive system enters the engine direct drive 2nd gear mode; When the vehicle is parked, the parking gear is locked, the first engaging and disengaging device is disengaged, the third engaging and disengaging device is disengaged, the second motor does not work, the engine drives the first motor to generate electricity, and the hybrid drive system enters a parking power generation mode.

17. The hybrid drive system according to claim 16, characterized in that: The parallel hybrid mode includes a parallel 1-gear power-assisting mode, a parallel 1-gear power-generating mode, a parallel 2-gear power-assisting mode, and a parallel 2-gear power-generating mode; The first engagement and disengagement device is disengaged, the third engagement and disengagement device is engaged, the engine is driven, the second motor is driven, the first motor is driven, generates electricity or idles, and the hybrid drive system enters a parallel 1st gear power-assisting mode; The first engagement and disconnection device is disconnected, the third engagement and disconnection device is engaged, the engine is driven, the second motor generates electricity, the first motor is driven, generates electricity or idles, and the hybrid drive system enters a parallel 1st gear power generation mode; The first engaging and disengaging device is engaged, the third engaging and disengaging device is disengaged, the engine is driven, the second motor is driven, the first motor is not operated, and the hybrid drive system enters a parallel 2-speed power-assisting mode; The first engaging and disengaging device is engaged, the third engaging and disengaging device is disengaged, the engine is driven, the second motor generates electricity, the first motor does not work, and the hybrid drive system enters a parallel 2-speed power generation mode.

18. The hybrid drive system according to claim 16, characterized in that: The hybrid drive system has a braking energy recovery mode in pure electric drive mode, a braking energy recovery mode in power split mode, a braking energy recovery mode in parallel hybrid 1st gear mode, a braking energy recovery mode in parallel hybrid 2nd gear mode, a braking energy recovery mode in engine direct drive 1st gear mode and a braking energy recovery mode in engine direct drive 2nd gear mode; When the vehicle brakes in the pure electric drive mode, the first engaging and disengaging device is disconnected, the third engaging and disengaging device is disconnected, the second motor is decelerated by the reverse torque to generate electricity, the engine and the first motor do not work, and the hybrid drive system enters the braking energy recovery mode in the pure electric drive mode; When the vehicle brakes in the power split mode, the first engaging and disengaging device is disconnected, the third engaging and disengaging device is disconnected, the second motor is decelerated by the reverse torque to generate electricity, the engine drives the first motor to generate electricity at the same time, and the hybrid drive system enters the braking energy recovery mode in the power split mode; When the vehicle is braked in the parallel hybrid 1st gear mode, the first engaging and disengaging device is disengaged, the third engaging and disengaging device is engaged, the engine is driven, the second motor is decelerated by the reverse torque to generate electricity, the first motor is driven, generates electricity or idles, and the hybrid drive system enters the braking energy recovery mode in the parallel hybrid 1st gear mode; When the vehicle is braked in the parallel hybrid 2nd gear mode, the first engaging / disengaging device is engaged, the third engaging / disengaging device is disengaged, the engine is driven, the second motor is decelerated by the reverse torque to generate electricity, the first motor does not work, and the hybrid drive system enters the braking energy recovery mode in the parallel hybrid 2nd gear mode; When the vehicle is braked in the engine direct drive 1st gear mode, the first engagement and disengagement device is disengaged, the third engagement and disengagement device is engaged, the engine is driven, the second motor is decelerated by the reverse torque to generate electricity, the first motor generates electricity or idles, and the hybrid drive system enters the brake energy recovery mode in the engine direct drive 1st gear mode; When the vehicle brakes in the engine direct drive 2nd gear mode, the first engagement and disengagement device is engaged, the third engagement and disengagement device is disengaged, the engine is driven, the second motor is decelerated by the reverse torque to generate electricity, the first motor does not work, and the hybrid drive system enters the braking energy recovery mode in the engine direct drive 2nd gear mode.

19. A vehicle, characterized in that: Comprising the hybrid power drive system as described in any one of claims 1-18.

20. A driving system control method, characterized in that: Based on the hybrid drive system according to any one of claims 1 to 18, the method comprises: Establishing a hierarchical distribution model of the working modes of the hybrid power drive system; wherein the hybrid power drive system has at least a pure electric drive mode, a power split mode, a parallel hybrid mode and an engine direct drive mode; Switching among the pure electric drive mode, power split mode, parallel hybrid mode and engine direct drive mode is performed according to the operating mode hierarchical distribution model.

21. The driving system control method according to claim 20, characterized in that: The hierarchical distribution model of the working mode has two layers. The hierarchical condition between the first layer and the second layer of the hierarchical distribution model of the working mode is V20 < V2, where V20 represents the first vehicle speed threshold and V2 represents the second vehicle speed threshold. The first layer of the hierarchical distribution model of the working mode is distributed with the power split mode and the pure electric drive mode, and the second layer of the hierarchical distribution model of the working mode is distributed with the pure electric drive mode, the parallel hybrid mode and the engine direct drive mode.

22. The driving system control method according to claim 20, characterized in that: The hierarchical distribution model of the working mode has three layers. The hierarchical condition between the first layer and the second layer of the hierarchical distribution model of the working mode is V10 < V1, and the hierarchical condition between the second layer and the third layer of the hierarchical distribution model of the working mode is V20 > V2, where V20 represents the first vehicle speed threshold, V2 represents the second vehicle speed threshold, V10 represents the third vehicle speed threshold, and V1 represents the fourth vehicle speed threshold. The parallel hybrid mode includes a parallel hybrid first gear mode and a parallel hybrid second gear mode, and the engine direct drive mode includes an engine direct drive first gear mode and an engine direct drive second gear mode. The first layer of the hierarchical distribution model of the working mode is distributed with the power split mode and the pure electric drive mode, the second layer of the hierarchical distribution model of the working mode is distributed with the pure electric drive mode, the parallel hybrid first gear mode and the engine direct drive first gear mode, and the third layer of the hierarchical distribution model of the working mode is distributed with the pure electric drive mode, the parallel hybrid second gear mode and the engine direct drive second gear mode.

23. The driving system control method according to claim 20, characterized in that: The method further includes: Setting a buffer area on the switching path of each working mode, and setting a buffer area on the switching path of the start and stop of the engine.

24. The driving system control method according to claim 20, characterized in that: The method further includes: Real-time monitoring of the SOC of the battery pack. When the current SOC of the battery pack is higher than the set upper limit value SOCh and the vehicle demand power Pr is lower than the set lower limit value Prl, control the engine not to work, and make the battery pack provide electric energy to the second motor alone to drive the vehicle. When the current SOC of the battery pack is lower than the set lower limit value SOCl, or the current SOC of the battery pack is between the set upper and lower limit values SOCh and SOCl and the vehicle demand power Pr is between the set upper and lower limit values Prh and Prl, or the vehicle demand power Pr is higher than the set upper limit value Prh, control the engine to work so that the engine drives the vehicle as the main power source. When the current SOC of the battery pack is higher than the set upper limit value SOCh and the vehicle demand power Pr is between the set upper and lower limit values Prh and Prl, or the current SOC of the battery pack is between the set upper and lower limit values SOCh and SOCl and the vehicle demand power Pr is lower than the set lower limit value Prl, set a transition zone to keep the working mode of the hybrid drive system in the previous working mode.

25. The driving system control method according to claim 24, characterized in that: The method further includes: In the power split mode of the hybrid drive system, when the engine demand power Per is lower than the minimum power value Pemin on the engine minimum fuel consumption line, the engine is controlled to operate at the minimum power value Pemin power point; when the engine demand power Per is higher than the maximum power value Pemax on the engine minimum fuel consumption line, the engine is controlled to operate at the maximum power value Pemax power point; when the engine demand power Per is between the maximum power value Pemax and the minimum power value Pemin on the engine minimum fuel consumption line, the engine is controlled to operate on its minimum fuel consumption line; wherein, the engine demand power Per is equal to the vehicle demand power Pr + loss power + accessory power.

26. The driving system control method according to claim 24, characterized in that: The method further comprises: In the engine direct drive mode or parallel hybrid mode, when the engine demand power Per is lower than the minimum power value Pemin on the engine minimum fuel consumption line, the engine is controlled to operate at the minimum power value Pemin power point; when the engine demand power Per is higher than the maximum power value Pemax on the engine minimum fuel consumption line, the engine is controlled to operate at the maximum power value Pemax power point; when the engine demand power Per is between the maximum power value Pemax and the minimum power value Pemin on the engine minimum fuel consumption line, the engine is controlled to operate on its minimum fuel consumption line Peopt; wherein, the engine demand power Per is equal to the vehicle demand power Pr + loss power + accessory power; When the engine demand power Per is higher than the engine minimum fuel consumption line Peopt and the current SOC of the battery pack is greater than the set lower limit value SOCl, the hybrid power drive system is switched to the parallel assist mode of the parallel hybrid mode; when the engine demand power Per is lower than the engine minimum fuel consumption line Peopt and the current SOC is less than the set upper limit value SOCh, the hybrid power drive system is switched to the parallel power generation mode of the parallel hybrid mode.

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