Hybrid drive system, vehicle, and drive system control method

Abstract

This invention relates to a hybrid drive system, a vehicle, and a drive system control method. The hybrid drive system includes an engine, a first motor, a first engagement / disengagement device, a planetary gear mechanism, a second motor, a first shaft, a second shaft, an intermediate shaft, an intermediate shaft gear, a main reducer drive gear, a main reducer driven gear, a motor drive gear, a parking gear, and a differential. Parking can be achieved by locking the parking gear. The planetary gear mechanism includes a sun gear, planet gears, a planet carrier, and a ring gear. The first shaft connects the rotor of the first motor to the sun gear. The engine is connected to the planet carrier. The ring gear has an external gear that meshes with the intermediate shaft gear. The first engagement / disengagement device connects the sun gear to a stationary component and is used to selectively engage or disengage the sun gear from the stationary component. This hybrid drive system can reduce EPB wear, thereby eliminating potential vehicle braking safety hazards.

Description

Technical Field

[0001] This invention belongs to the field of hybrid technology, and in particular relates to a hybrid drive system, a vehicle, and a drive system control method. Background Technology

[0002] Currently, hybrid electric vehicle drive systems mainly include three basic forms: series, parallel, and series-parallel. In a series drive system, there is no mechanical connection between the engine and the output shaft, allowing for optimized speed / torque control. However, all energy must undergo two conversions between mechanical and electrical power before being transferred to the output shaft, resulting in significant energy loss. Parallel drive systems offer high transmission efficiency, but the mechanical connection between the engine and the output shaft cannot guarantee that the engine will always operate within its optimal range, typically used for medium- to high-speed driving conditions. Series-parallel drive systems combine the advantages of both series and parallel systems, achieving both optimized engine control and efficient control at medium to high speeds.

[0003] Hybrid systems are further divided into series-parallel hybrid systems and power shunt hybrid systems. Among power shunt hybrid systems, the single-stage input power shunt structure is the simplest and most widely used, with Toyota being a representative example, starting to mass-produce and install it in automobiles in 1997.

[0004] However, existing power split hybrid systems have the following problems: In parking / stopping mode, the drive motor needs to stall to generate electricity from the generator. This consumes energy and is prone to stalling, causing the drive motor to overheat, demagnetize, and fail. Furthermore, forcibly implementing the parking generator function requires frequent activation of the EPB (Electrical Park Brake), which accelerates EPB wear and poses a potential safety hazard to vehicle braking. Summary of the Invention

[0005] The technical problem to be solved by this invention is: in the existing power split hybrid system, in the parking / stopping mode, the drive motor needs to generate electricity by the generator, the drive motor consumes energy and is very prone to stalling, causing the drive motor to overheat and demagnetize and fail. The invention provides a hybrid drive system, vehicle and drive system control method.

[0006] To address the aforementioned technical problems, in one aspect, embodiments of the present invention provide a hybrid power drive system, including an engine, a first motor, a first engagement / disengagement device, a planetary gear mechanism, a second motor, a first shaft, a second shaft, an intermediate shaft, an intermediate shaft gear, a main reducer drive gear, a main reducer driven gear, a motor drive gear, a parking gear, and a differential; the intermediate shaft gear and the main reducer drive gear are mounted on the intermediate shaft, the main reducer driven gear is mounted on the differential housing and meshes with the main reducer drive gear, the motor drive gear and the parking gear are mounted 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; parking can be achieved by locking the parking gear; The planetary gear mechanism includes a sun gear, planet gears, a planet 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 planet carrier. The ring gear is provided with an external gear that meshes with the intermediate shaft gear. The first engagement / disengagement device is connected between the sun gear and the stationary component, and is used to selectively engage or disengage the sun gear and the stationary component.

[0007] On the other hand, embodiments of the present invention also provide a vehicle that includes the above-described hybrid drive system.

[0008] In the hybrid drive system and vehicle of this invention, the motor drive gear and parking gear are mounted on a second shaft connected to the rotor of the second motor. The motor drive gear meshes with an intermediate shaft gear mounted on an intermediate shaft. By locking the parking gear, the vehicle can be parked. Since the motor drive gear is connected to the rotor of the second motor, and the intermediate shaft gear meshing with the motor drive gear is mounted on the intermediate shaft, the high speed ratio of the gear pair formed by the motor drive gear and the intermediate shaft gear allows for locking the vehicle with only a small torque when parking or stopping. This achieves parking power generation and parking power generation without energy consumption, eliminating the need for the second motor (drive motor) to stall the first motor (generator) for power generation. This avoids the second motor consuming energy and experiencing overheating and demagnetization failure due to stalling, and also avoids the problem of frequent EPB activation required to forcibly achieve parking power generation, reducing EPB wear and thus eliminating potential vehicle braking safety hazards.

[0009] Furthermore, embodiments of the present invention also provide a drive system control method, which is based on the above-mentioned hybrid drive system, the method comprising: A hierarchical distribution model of the operating modes of the hybrid drive system is established; wherein, the hybrid drive system has at least a pure electric drive mode, a power split mode, a parallel hybrid mode, and an engine direct drive mode; The switching between the pure electric drive mode, power split mode, parallel hybrid mode and engine direct drive mode is performed according to the hierarchical distribution model of the working mode. Attached Figure Description

[0010] Figure 1 This is a simplified structural diagram of the hybrid power drive system provided in the first embodiment of the present invention; Figure 2 This is a simplified structural diagram of the hybrid power drive system provided in the second embodiment of the present invention; Figure 3 This is a framework diagram of the drive system control method provided in the third embodiment of the present invention; Figure 4 This is a diagram showing the battery SOC state control requirements of the drive system control method provided in the third embodiment of the present invention; Figure 5 This is a hierarchical distribution model diagram of the working mode of the drive system control method provided in the third embodiment of the present invention; Figure 6 This is the first layer distribution diagram of the hierarchical distribution model of the working mode of the drive system control method provided in the third embodiment of the present invention; Figure 7 This is the second layer distribution diagram of the hierarchical distribution model of the working mode of the drive system control method provided in the third embodiment of the present invention; Figure 8 This is a simplified structural diagram of the hybrid power drive system provided in the fourth embodiment of the present invention; Figure 9 This is a hierarchical distribution model diagram of the working mode of the drive system control method provided in the fifth embodiment of the present invention; Figure 10 This is the first layer distribution diagram of the hierarchical distribution model of the working mode of the drive system control method provided in the fifth embodiment of the present invention; Figure 11 This is the second layer distribution diagram of the hierarchical distribution model of the working mode of the drive system control method provided in the fifth embodiment of the present invention; Figure 12 This is the third layer distribution diagram of the working mode hierarchical distribution model of the drive system control method provided in the fifth embodiment of the present invention.

[0011] The reference numerals in the accompanying drawings are as follows: 1. Engine; 2. First motor; 3. First engagement / disengagement device; 4. Planetary gear mechanism; 41. Sun gear; 42. Planetary gears; 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 reducer drive gear; 20. Main reducer driven gear; 30. Motor drive gear; 40. Parking gear; 50. Differential; 60. Ring gear external gear; 70. Second engagement / disengagement device; 80. Second engagement / disengagement device. Detailed Implementation

[0012] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0013] The hybrid drive system provided in this embodiment of the invention includes an engine, a first motor, a first engagement / disengagement device, a planetary gear mechanism, a second motor, a first shaft, a second shaft, an intermediate shaft, an intermediate shaft gear, a main reducer drive gear, a main reducer driven gear, a motor drive gear, a parking gear, and a differential. The intermediate shaft gear and the main reducer drive gear are mounted on the intermediate shaft. The main reducer driven gear is mounted on the housing of the differential and meshes with the main reducer drive gear. The motor drive gear and the parking gear are mounted on the second shaft. The motor drive gear meshes with the intermediate shaft gear. One end of the second shaft is connected to the rotor of the second motor. Parking can be achieved by locking the parking gear. The planetary gear mechanism includes a sun gear, planet gears, a planet 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 planet carrier. The ring gear has an external gear that meshes with the intermediate shaft gear. The first engagement / disengagement device is connected between the sun gear and a stationary component, and is used to selectively engage or disengage the sun gear and the stationary component.

[0014] In some embodiments, the stationary component is the housing of the first motor.

[0015] In other embodiments, the stationary component is the housing of the planetary gear mechanism.

[0016] In other embodiments, the stationary component may also be other relatively stationary components on the vehicle body.

[0017] In some embodiments, the first shaft, the second shaft, and the intermediate shaft are arranged parallel to each other at intervals. This shortens the axial length of the hybrid drive system, which is beneficial for the overall vehicle layout.

[0018] In some embodiments, the first motor and the engine are located on opposite sides of the first shaft, and the second motor and the first motor are located on the same side of the first shaft. This arrangement allows for a more compact layout, with the engine and two motors located on opposite sides of the hybrid drive system. Furthermore, having the two motors on the same side facilitates the arrangement of the motor controller and reduces the length of the motor wiring harness.

[0019] In some embodiments, the first motor, the first engagement / disengagement device, the planetary gear mechanism, and the engine are arranged sequentially along the axial direction of the first shaft. This results in a compact structural arrangement, which is beneficial for the overall vehicle layout.

[0020] In some embodiments, the second motor, the motor drive gear, and the parking gear are arranged sequentially along the axial direction of the second shaft. This results in a compact structural arrangement, which is beneficial for the overall vehicle layout.

[0021] In some embodiments, the diameter of the motor drive gear is smaller than the diameter of the intermediate shaft gear; the diameter of the external gear of the gear ring is smaller than the diameter of the intermediate shaft gear. That is, the diameter of the intermediate shaft gear is larger than the diameters of both the motor drive gear and the external gear of the gear ring. Thus, the output power of the second motor is reduced and transmitted through the motor drive gear and the intermediate shaft gear, and the power output from the gear ring is reduced and transmitted through the external gear of the gear ring and the intermediate shaft gear.

[0022] In some embodiments, a first end of the first engagement disconnection device is connected to the stationary member, and a second end of the first engagement disconnection device is connected to the first shaft. This allows the entire first engagement disconnection device to be located between the stationary member and the first shaft, resulting in a more compact arrangement and less space occupation.

[0023] The first end and the second end of the first engagement disconnection device, one of which is the active end (the end driven by the actuator) and the other is the driven end.

[0024] In some embodiments, the hybrid drive system further includes a damping element connected between the engine and the planetary carrier. The damping element is a single-mass flywheel, a dual-mass flywheel, a torsional damper, or a torque converter. The damping element absorbs engine vibrations, improving the driving experience.

[0025] In some embodiments, the first engagement disconnection device is a clutch, synchronizer, or brake.

[0026] In some embodiments, the clutch is a wet multi-plate clutch. Wet multi-plate clutches are more reliable than dry clutches.

[0027] 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; when the first engagement disconnect device is disconnected, the second motor is driven, the engine and the first motor are not working, and the hybrid drive system enters the pure electric drive mode; when the first engagement disconnect device is disconnected, the engine drives the first motor to generate electricity, and all or part of the electrical energy generated by the first motor is provided to the second motor, and the second motor drives, the hybrid drive system enters the power split mode; when the first engagement disconnect device is engaged, the engine is driven, the second motor drives or generates electricity, the first motor is not working, and the hybrid drive system enters the parallel hybrid mode; when the first engagement disconnect device is engaged, the engine is driven, the first motor is not working, 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 disconnect device is disconnected, the second motor is not working, the engine drives the first motor to generate electricity, and the hybrid drive system enters the parking power generation mode.

[0028] By controlling the operating states of the engine, the first motor, and the second motor, and selectively engaging or disengaging the first engagement / disengagement device, multiple driving modes can be achieved, including pure electric drive mode, power split mode, parallel hybrid mode, engine direct drive mode, and parking generator mode. Input-type power split is the optimal hybrid configuration for single-stage power split, and it is particularly efficient at low and medium speeds. If the battery charge is insufficient after starting in pure electric mode, the input-type power split mode can be switched to.

[0029] 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 drives, the second motor drives, the first motor does not work, and the hybrid drive system enters the parallel assist mode; when the first engagement / disengagement device is engaged, the engine drives, the second motor generates electricity, the first motor does not work, and the hybrid drive system enters the parallel power generation mode.

[0030] In some embodiments, the hybrid drive system has a regenerative braking mode in pure electric drive mode, a regenerative braking mode in power split mode, a regenerative braking mode in parallel hybrid mode, and a regenerative braking mode in engine direct drive mode. In pure electric drive mode, when the vehicle brakes, the first engagement disconnect device is disengaged, the second motor receives reverse torque for deceleration and power generation, the engine and the first motor do not operate, and the hybrid drive system enters the regenerative braking mode in pure electric drive mode. In power split mode, when the vehicle brakes, the first engagement disconnect device is disengaged, the second motor receives reverse torque for deceleration and power generation, the engine drives the first motor to generate electricity, and the hybrid drive system enters the regenerative braking mode in power split mode. In parallel hybrid mode, when the vehicle brakes, the first engagement disconnect device is engaged, the second motor receives reverse torque for deceleration and power generation, the engine drives, and the first motor does not operate, and the hybrid drive system enters the regenerative braking mode in parallel hybrid mode. In engine direct drive mode, when the vehicle brakes, the first engagement disconnect device is engaged, the second motor receives reverse torque for deceleration and power generation, the engine drives, and the first motor does not operate, and the hybrid drive system enters the regenerative braking mode in engine direct drive mode.

[0031] Thus, each driving mode has a corresponding regenerative braking mode, and all can utilize the second motor to achieve efficient regenerative braking. In another embodiment, a second engagement / disengagement device is also included. The first shaft includes a first shaft segment and a second shaft segment that are coaxial and spaced apart from each other. The first end of the first engagement / disengagement 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 engagement / disengagement device is connected between the other end of the first shaft segment and the second end of the first engagement / disengagement device, and the second shaft segment is connected between the second end of the first engagement / disengagement device and the sun gear.

[0032] Engaging and disengaging the second engagement / disengagement device enables the power connection and disconnection between the first motor and the sun gear. This allows the second motor to start in pure electric mode. By disengaging the second engagement / disengagement device, the first motor is disconnected from the sun gear, reducing the load on the sun gear to zero. This prevents the second motor from dragging the engine and the first motor in pure electric drive mode, improving system efficiency and extending the driving range of electric vehicles (especially PHEV models).

[0033] By utilizing the torque-locking action of the second motor and the parking gear, the freedom of the gear ring can be eliminated. The second engagement / disengagement device can be selectively engaged, allowing the engine to be quickly restarted via the first motor.

[0034] In an embodiment with a first engagement / disengagement device and a second engagement / disengagement 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; when the first engagement / disengagement device is disconnected and the second engagement / disengagement device is disconnected, the second motor drives, the engine and the first motor do not operate, and the hybrid drive system enters the pure electric drive mode; when the first engagement / disengagement device is disconnected and the second engagement / disengagement device is engaged, the engine drives the first motor to generate electricity, and all or part of the electrical energy generated by the first motor is provided to the second motor, the second motor drives, and the hybrid drive system enters the power split mode. Hybrid drive system enters parallel hybrid mode when: the first engagement / disengagement device is engaged, the second engagement / disengagement device is disengaged, the engine drives, the second motor drives or generates electricity, the first motor does not work, and the hybrid drive system enters engine direct drive mode; when the vehicle is parked, the parking gear is locked, the first engagement / disengagement device is disengaged, the second engagement / disengagement device is engaged, the second motor does not work, the engine drives the first motor to generate electricity, and the hybrid drive system enters parking power generation mode.

[0035] In an embodiment having a first engagement / disengagement device and a second engagement / disengagement device, the parallel hybrid mode includes a parallel assist mode and a parallel power generation mode; when the first engagement / disengagement device is engaged and the second engagement / disengagement device is disengaged, the engine drives, the second motor drives, and the first motor does not work, the hybrid drive system enters the parallel assist mode; when the first engagement / disengagement device is engaged and the second engagement / disengagement device is disengaged, the engine drives, the second motor generates electricity, and the first motor does not work, the hybrid drive system enters the parallel power generation mode.

[0036] In an embodiment with a first engagement disconnection device and a second engagement disconnection device, 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 disconnection device is disconnected, the second engagement 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 the braking energy recovery mode in pure electric drive mode. When the vehicle brakes in the power split mode, the first engagement disconnect device is disengaged, the second engagement disconnect device is engaged, the second motor receives reverse torque to decelerate and generate electricity, and the engine drives the first motor to generate electricity simultaneously. 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 engagement disconnect device is engaged, the second engagement disconnect device is disengaged, the second motor receives reverse torque to decelerate and generate electricity, the engine drives, and the first motor does not operate. 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 disconnect device is engaged, the second engagement disconnect device is disengaged, the second motor receives reverse torque to decelerate and generate electricity, the engine drives, and the first motor does not operate. The hybrid drive system enters the braking energy recovery mode in the engine direct drive mode.

[0037] In some embodiments, a third engagement disconnection device is further included, which is connected between the second end of the first engagement disconnection device and the planetary carrier. In this embodiment, a second engagement disconnection device is not included.

[0038] In an embodiment with a first engagement disconnect device and a third engagement disconnect device, 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 generator mode; when the first engagement disconnect device is disconnected and the third engagement disconnect device is disconnected, the second motor drives, the engine and the first motor do not work, and the hybrid drive system enters the pure electric drive mode; when the first engagement disconnect device is disconnected and the third engagement disconnect device is disconnected, the engine drives and simultaneously drives the first motor to generate electricity, and all or part of the electrical energy generated by the first motor is provided to the second motor, the second motor drives, and the hybrid drive system enters the power split mode; when the first engagement disconnect device is disconnected and the third engagement disconnect device is engaged, the engine drives, the second motor drives or generates electricity, the first motor drives, generates electricity, or idles, and the hybrid drive system enters the parallel hybrid 1st gear mode; when the first engagement disconnect device is engaged and the third engagement disconnect device is disconnected, 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 1st gear mode. When the vehicle is parked, the parking gear is locked, the first engagement disconnection device is disengaged, the third engagement disconnection device is engaged, the engine drives, the first motor idles, the second motor idles, and the hybrid drive system enters engine direct drive mode 1; when the first engagement disconnection device is engaged, the third engagement disconnection device is disengaged, the engine drives, the first motor does not work, the second motor idles, and the hybrid drive system enters engine direct drive mode 2; when the vehicle is parked, the parking gear is locked, the first engagement disconnection device is disengaged, the third engagement disconnection device is disengaged, the second motor does not work, the engine drives the first motor to generate electricity, and the hybrid drive system enters parking power generation mode.

[0039] In an embodiment with a first engagement / disengagement device and a third engagement / disengagement device, the parallel hybrid mode includes a parallel 1st gear assist mode, a parallel 1st gear power generation mode, a parallel 2nd gear assist mode, and a parallel 2nd gear power generation mode; when the first engagement / disengagement device is disengaged and the third engagement / disengagement device is engaged, the engine drives, the second motor drives, and the first motor drives, generates electricity, or idles, the hybrid drive system enters the parallel 1st gear assist mode; when the first engagement / disengagement device is disengaged and the third engagement / disengagement device is engaged, the engine drives, the second motor generates electricity, and the first motor drives, generates electricity, or idles, the hybrid drive system enters the parallel 1st gear power generation mode; when the first engagement / disengagement device is engaged and the third engagement / disengagement device is disengaged, the engine drives, the second motor drives, and the first motor does not work, the hybrid drive system enters the parallel 2nd gear assist mode; when the first engagement / disengagement device is engaged and the third engagement / disengagement device is disengaged, the engine drives, the second motor generates electricity, and the first motor does not work, the hybrid drive system enters the parallel 2nd gear power generation mode.

[0040] In an embodiment with a first engagement disconnect device and a third engagement disconnect device, 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. In the pure electric drive mode, when the vehicle brakes, the first engagement disconnect device and the third engagement disconnect device are disconnected, the second motor receives reverse torque for deceleration and power generation, the engine and the first motor do not operate, and the hybrid drive system enters the braking energy recovery mode in pure electric drive mode. In the power split mode, when the vehicle brakes, the first engagement disconnect device and the third engagement disconnect device are disconnected, the second motor receives reverse torque for deceleration and power generation, the engine drives the first motor to generate electricity simultaneously, and the hybrid drive system enters the braking energy recovery mode in power split mode. In the parallel hybrid 1st gear mode, when the vehicle brakes, the first engagement disconnect device is disconnected, the third engagement disconnect device is engaged, and the engine... When the vehicle brakes in parallel hybrid mode 1, the first motor drives the engine, the second motor is decelerated by reverse torque to generate electricity, and the first motor drives, generates electricity, or idles. In parallel hybrid mode 2, when the vehicle brakes, the first engagement disconnect device engages, the third engagement disconnect device disengages, the engine drives, the second motor is decelerated by reverse torque to generate electricity, and the first motor does not operate. In engine direct drive mode 1, when the vehicle brakes, the first engagement disconnect device disengages, the third engagement disconnect device engages, the engine drives, the second motor is decelerated by reverse torque to generate electricity, and the first motor generates electricity or idles. In engine direct drive mode 2, when the vehicle brakes, the first engagement disconnect device engages, the third engagement disconnect device disengages, the engine drives, the second motor is decelerated by reverse torque to generate electricity, and the first motor generates electricity or idles. In engine direct drive mode 2, when the vehicle brakes, the first engagement disconnect device engages, the third engagement disconnect device disengages, the engine drives, the second motor is decelerated by reverse torque to generate electricity, and the first motor does not operate. In engine direct drive mode 2, when the vehicle brakes, the hybrid system enters engine direct drive mode 2 and brake energy recovery mode.

[0041] In the embodiment with a first engagement / disengagement device and a third engagement / disengagement device, by controlling the operating states of the engine, the first motor, and the second motor, and selectively engaging or disengaging the first engagement / disengagement device and the second engagement / disengagement device, multiple driving modes can be achieved, including pure electric drive 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. Furthermore, in the engine-driven mode, the engine can have two 2nd gear positions, making the hybrid drive system of this embodiment suitable for urban driving conditions and small to medium-sized vehicles, balancing the vehicle's power and economy.

[0042] In the hybrid drive system of this invention, the motor drive gear and parking gear are mounted on a second shaft connected to the rotor of the second motor. The motor drive gear meshes with an intermediate shaft gear mounted on an intermediate shaft. By locking the parking gear, the vehicle can be parked. Since the motor drive gear is connected to the rotor of the second motor, and the intermediate shaft gear meshing with the motor drive gear is mounted on the intermediate shaft, the high speed ratio of the gear pair formed by the motor drive gear and the intermediate shaft gear allows for locking the vehicle with only a small torque when parking or stopping. This achieves parking and parking power generation without energy consumption, eliminating the need for the second motor (drive motor) to stall the first motor (generator) for power generation. This avoids the second motor consuming energy and experiencing overheating and demagnetization failure due to stalling, and also avoids the problem of frequent EPB activation required to forcibly achieve parking power generation, reducing EPB wear and thus eliminating potential vehicle braking safety hazards.

[0043] In addition, the second motor can participate in driving during mode switching, so there is no power interruption and the driving experience is better.

[0044] In addition, the first motor can increase speed and torque through a planetary gear mechanism, which can effectively reduce the size of the first motor.

[0045] In addition, this hybrid drive system can be applied to both HEV and PHEV models, and has a good platform integration.

[0046] In addition, this hybrid drive system has corresponding regenerative braking modes in each driving mode, and can utilize the second motor to achieve efficient regenerative braking. The regenerative braking covers all driving conditions, has high energy recovery efficiency, and can improve the vehicle's range.

[0047] The following combination Figures 1 to 12 This invention provides a detailed description of the hybrid power drive system and drive system control method provided in the embodiments of the present invention.

[0048] First Embodiment like Figure 1As shown, the hybrid drive system provided in the first embodiment of the present invention includes an engine 1, a first motor 2, a first engagement / disengagement 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 reducer drive gear 10, a main reducer driven gear 20, a motor drive 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 the left wheel, and the other is the right wheel.

[0049] The intermediate shaft gear 9 and the main reduction drive gear 10 are disposed on the intermediate shaft 8. The intermediate shaft gear 9 is fixed (e.g., splined) on the intermediate shaft 8 or integrally formed on the intermediate shaft 8, and the main reduction drive gear 10 is fixed (e.g., splined) on the intermediate shaft 8 or integrally formed on the intermediate shaft 8.

[0050] The main reducer driven gear 20 is disposed on the housing of the differential 50 and meshes with the main reducer drive gear 10. The main reducer driven gear 20 is fixed (e.g., splined connection) or integrally formed on the housing of the differential 50.

[0051] The motor drive gear 30 and the parking gear 40 are mounted on the second shaft 7. The motor drive gear 30 meshes with the intermediate shaft gear 9. 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. Parking can be achieved by locking the parking gear 40, for example, by engaging the parking gear 40 with a parking pawl.

[0052] The planetary gear mechanism 4 includes a sun gear 41, planet gears 42, a planet carrier 43, and a ring gear 44. The first shaft 6 connects the rotor of the first motor 2 to the sun gear 41. The engine 1 is connected to the planet carrier 43. The ring gear 44 is provided with an external gear 60 that meshes with the intermediate shaft gear 9. The external gear 60 is fixed (e.g., splined) to the ring gear 44 or integrally formed on the ring gear 44. The first engagement / 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 from the stationary component. The first shaft 6, the second shaft 7, and the intermediate shaft 8 are arranged parallel to each other at intervals. This shortens the axial length of the hybrid drive system, which is beneficial for the overall vehicle layout.

[0053] The first motor 2 and the engine 1 are located on opposite 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 opposite sides of the hybrid drive system, which is more compact. Furthermore, having the two motors on the same side facilitates the arrangement of the motor controller and reduces the length of the motor wiring harness.

[0054] The first motor 2, the first engagement / disengagement device 3, the planetary gear mechanism 4, and the engine 1 are arranged sequentially along the axial direction of the first shaft 6. This arrangement results in a compact structure, which is beneficial for the overall vehicle layout.

[0055] The second motor 5, the motor drive gear 30, and the parking gear 40 are arranged sequentially along the axial direction of the second shaft 7. This arrangement results in a compact structure, which is beneficial for the overall vehicle layout.

[0056] The diameter of the motor drive gear 30 is smaller than the diameter of the intermediate shaft gear 9; the diameter of the gear ring 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 both the motor drive gear 30 and the gear ring external gear 60. Thus, the output power of the second motor 5 is reduced and transmitted through the motor drive gear 30 and the intermediate shaft gear 9, and the power output from the gear ring 44 is reduced and transmitted through the gear ring external gear 60 and the intermediate shaft gear 9.

[0057] The first end of the first engagement disconnection device 3 is connected to the stationary component, and the second end of the first engagement disconnection device 3 is connected to the first shaft 6. This arrangement places the entire first engagement disconnection device 3 between the stationary component and the first shaft 6, resulting in a more compact arrangement that does not occupy excessive space. Of the first and second ends of the first engagement disconnection device 3, one is the active end (the end driven by the actuator), and the other is the driven end.

[0058] In this embodiment, the first engagement disconnection device 3 is a brake.

[0059] However, in other embodiments, a clutch or synchronizer and other components with similar functions may be used instead of a brake.

[0060] When the first engagement / 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 / 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 jointly with the engine 1.

[0061] The hybrid drive system may also include a damping element connected between the engine 1 and the planetary carrier 43, wherein the damping element is a single-mass flywheel, a dual-mass flywheel, a torsional damper, or a hydraulic torque converter.

[0062] 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 set on the intermediate shaft 8, by means of the large speed ratio of the gear pair formed by the motor drive gear 30 and the intermediate shaft gear 9, only a small torque is needed to lock the vehicle when the vehicle is parked or stopped, so that parking power generation and parking power generation can be realized without energy consumption. It does not require the second motor 5 (drive motor) to stall the first motor 2 (generator) to generate electricity. It can avoid the second motor 5 consuming energy and causing overheating and demagnetization failure of the second motor 5 due to stalling. It can also avoid the problem of frequent EPB starting required to forcibly realize the parking power generation function, reduce EPB wear, and thus eliminate vehicle braking safety hazards.

[0063] 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 state of engine 1, first motor 2 and second motor 5 and selectively engaging or disengaging the first engagement / disengagement device 3.

[0064] Furthermore, each driving mode has a corresponding regenerative braking mode, all of which utilize the second motor for efficient regenerative braking. During mode switching, the second motor 5 can participate in driving without power interruption, resulting in a good driving experience. The first motor 2 can increase speed and torque through the planetary gear mechanism 4, effectively reducing its size. This hybrid drive system can cover both HEV and PHEV models, demonstrating good platform integration.

[0065] The control parameters for each drive mode are shown in Table 1 below: Table 1 In Table 1, " / " indicates that it is not working.

[0066] The power transmission in each driving mode is as follows: (1) Pure electric drive mode When the first engagement disconnection device 3 is disconnected, the second motor 5 is driven, and the engine 1 and the first motor 2 cease operation, thus the hybrid drive system enters pure electric drive mode. At this time, the power transmission route is: second motor 5 - motor drive gear 30 - intermediate shaft gear 9 - main reducer drive gear 10 - main reducer driven gear 20 - differential 50. This mode is primarily used for starting and low-to-medium speed vehicle operation.

[0067] (3) Power shunt mode When the first engagement disconnection device 3 is disconnected, the engine 1 drives the first motor 2 to generate electricity. All or part of the electrical energy generated by the first motor 2 is supplied to the second motor 5, which then drives the hybrid drive system into a power split mode. At this time, the power transmission route is divided into three paths. The first path is: second motor 5 - motor drive gear 30 - intermediate shaft gear 9 - main reducer drive gear 10 - main reducer driven gear 20 - differential 50; the second path is: engine 1 - planetary carrier 43 - planetary gears 42 - ring gear 44 - ring gear external gear 60 - intermediate shaft gear 9 - main reducer drive gear 10 - main reducer driven gear 20 - differential 50; the third path (power generation path) is: engine 1 - planetary carrier 43 - planetary gears 42 - sun gear 41 - first motor 2. This mode is mainly used to cover low-to-medium speed operating conditions of the vehicle, while also covering high-speed operating conditions exceeding mechanical limits. When the power is sufficient and the battery pack SOC is not saturated, the power of the first motor 2 can partially 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 output by the battery discharge through the second motor 5.

[0068] (4) Parallel hybrid mode When the first engagement / disengagement device 3 engages, the engine 1 drives, the second motor 5 drives or generates electricity, the first motor 2 does not operate, and the hybrid drive system enters parallel hybrid mode. Depending on whether the second motor 5 assists or drives, the parallel hybrid mode can be further divided into parallel assist mode and parallel power generation mode. In parallel assist mode, the power transmission route is divided into two paths: the first path is: second motor 5 - motor drive gear 30 - intermediate shaft gear 9 - main reducer drive gear 10 - main reducer driven gear 20 - differential 50; the second path is: engine 1 - planetary carrier 43 - planetary gears 42 - ring gear 44 - ring gear external gear 60 - intermediate shaft gear 9 - main reducer drive gear 10 - main reducer driven gear 20 - differential 50. In parallel power generation mode, the power transmission route is divided into two paths. The first path is: Engine 1 - Planetary Carrier 43 - Planetary Gears 42 - Ring Gear 44 - External Gear 60 - Intermediate Shaft Gear 9 - Motor Drive Gear 30 - Second Motor 5; the second path is: Engine 1 - Planetary Carrier 43 - Planetary Gears 42 - Ring Gear 44 - External Gear 60 - Intermediate Shaft Gear 9 - Main Reducer Drive Gear 10 - Main Reducer Drive Gear 20 - Differential 50. Parallel hybrid mode is mainly used for high-speed hybrid driving. Most of the power of Engine 1 is directly used for driving (without electrical power conversion). Under the premise of meeting the overall vehicle power requirements, the first motor 2 can adjust the torque operating range of Engine 1, enabling torque decoupling of Engine 1. When the battery pack SOC is sufficient, Engine 1 operates within its optimal torque range, resulting in efficient system operation. In parallel assist mode, there are two power sources (Engine 1 + Second Motor 5), providing the vehicle with good power performance.

[0069] (5) Engine direct drive mode When the first engagement / disengagement device 3 engages, the engine 1 is driven, the first motor 2 is not working, and the second motor 5 idles, the hybrid drive system enters engine direct drive mode. At this time, the power transmission route is: engine 1 - planetary carrier 43 - planetary gears 42 - ring gear 44 - external gear 60 - intermediate shaft gear 9 - main reducer drive gear 10 - main reducer driven gear 20 - differential 50. This mode is mainly used for high-speed engine direct drive. To avoid power backflow caused by input power splitting, the system must switch to this mode when the vehicle speed approaches the mechanical point. In this mode, the power of engine 1 is directly driven without electrical power conversion, resulting in high system efficiency.

[0070] (6) Parking power generation mode When the vehicle is parked, the parking gear 40 is locked, the first engagement disconnection device 3 is disengaged, the second motor 5 is not working, and the engine 1 drives the first motor 2 to generate electricity, thus the hybrid drive system enters the parking power generation mode. At this time, the power transmission route is: engine 1 - planetary carrier 43 - planetary gear 42 - sun gear 41 - first motor 2. This mode is mainly used in parking power depletion situations such as traffic lights.

[0071] (7) Braking energy recovery mode in pure electric drive mode When the vehicle brakes in the pure electric drive mode, the first engagement disconnect device 3 disconnects, the second motor 5 receives reverse torque to decelerate and generate electricity, the engine 1 and the first motor 2 do not operate, 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 reducer driven gear 20 - main reducer drive gear 10 - intermediate shaft gear 9 - motor drive gear 30 - second motor 5. This mode is applied to vehicle braking energy recovery in pure electric drive mode.

[0072] (8) Braking energy recovery mode under power split mode When the vehicle brakes in the power-split mode, the first engagement disconnect device 3 disconnects, and the second motor 5 is decelerated and generates electricity under reverse torque. Simultaneously, the engine 1 drives the first motor 2 to generate electricity, and the hybrid drive system enters the braking energy recovery mode under the power-split mode. At this time, the braking energy recovery route is: wheel - differential 50 - main reducer driven gear 20 - main reducer drive gear 10 - intermediate shaft gear 9 - motor drive gear 30 - second motor 5. This mode is applied to vehicle braking energy recovery under power-split mode.

[0073] (9) Braking energy recovery mode in parallel hybrid mode When the vehicle brakes in the parallel hybrid mode, the first engagement / disengagement device 3 engages, the second motor 5 receives reverse torque to decelerate and generate electricity, the engine 1 is driven, and the first motor 2 does not operate. The hybrid drive system then enters the braking energy recovery mode in the parallel hybrid mode. At this time, the braking energy recovery route is: wheel - differential 50 - main reducer driven gear 20 - main reducer drive gear 10 - intermediate shaft gear 9 - motor drive gear 30 - second motor 5. This mode is applied to vehicle braking energy recovery in parallel hybrid mode.

[0074] (10) Braking energy recovery mode in engine direct drive mode When the vehicle brakes in the engine direct drive mode, the first engagement disconnect device 3 engages, the second motor 5 receives reverse torque for deceleration and power generation, the engine 1 is driven, the first motor 2 does not operate, and the hybrid drive system enters the brake energy recovery mode in engine direct drive mode. At this time, the brake energy recovery route is: wheel - differential 50 - main reducer driven gear 20 - main reducer drive gear 10 - intermediate shaft gear 9 - motor drive gear 30 - second motor 5. This mode is applied to vehicle brake energy recovery in engine direct drive mode.

[0075] Second Embodiment Figure 2 The hybrid drive system shown is a second embodiment of the present invention. Unlike the first embodiment, it further includes a second engagement disconnection device 70. The first shaft 6 includes a first shaft segment 61 and a second shaft segment 62 that are coaxial and spaced apart from each other. The first end of the first engagement 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 disconnection device 70 is connected between the other end of the first shaft segment 61 and the second end of the first engagement disconnection device 3. The second shaft segment 62 is connected between the second end of the first engagement disconnection device 3 and the sun gear 41.

[0076] The engagement and disengagement of the second engagement / disengagement device 3 enables the power connection and disconnection between the first motor 2 and the sun gear 41. Thus, in pure electric drive mode, by disengaging the second engagement / disengagement device 70, the first motor 2 is disconnected from the sun gear 41, resulting in zero load on the sun gear. This prevents the second motor 5 from dragging the engine 1 and the first motor 2 in pure electric drive mode, improving system efficiency and extending the driving range of electric vehicles (especially PHEV models).

[0077] The torque-locking action of the second motor 5 and the parking gear 30 eliminates the degree of freedom of the gear ring. The second engagement / disengagement device 70 can be selectively engaged, allowing the engine 1 to be quickly restarted via the first motor 2.

[0078] The second engagement / disengagement device 70 is a clutch. Preferably, the clutch is a wet multi-plate clutch. Using a wet multi-plate clutch is more reliable than using a dry clutch.

[0079] However, the second engagement disconnection device 70 can also be a component with similar functions, such as a synchronizer or a brake.

[0080] In this embodiment, the hybrid drive system also features a pure electric drive mode, a power split mode, a parallel hybrid mode, an engine direct drive mode, and a parking power generation mode. Furthermore, each drive mode has a corresponding regenerative braking mode, all of which utilize a second motor to achieve efficient regenerative braking.

[0081] For control in each driving mode, refer to Table 2 below: Table 2 In Table 2, " / " indicates non-operation.

[0082] In the second embodiment, power transmission in each driving mode is similar to that in the first embodiment.

[0083] Third Embodiment Referring to Figures 3 to 7 , an embodiment of the present invention further provides a control method for a driving system, which is based on the hybrid power driving system of the first and second embodiments, and the method comprises: establishing a hierarchical distribution model of working modes for the hybrid power driving system; wherein the hybrid power driving system has at least a pure electric drive mode, a power split mode, a parallel hybrid mode and an engine direct drive mode.

[0084] switching among the pure electric drive mode, the power split mode, the parallel hybrid mode and the engine direct drive mode according to the hierarchical distribution model of working modes.

[0085] Referring to Figures 5 to 7 , the hierarchical distribution model of working modes has two layers. In order to avoid frequent mode switching between the two layers, the layering condition between the first layer and the second layer of the hierarchical distribution model of working modes is V20<V2; the first layer of the hierarchical distribution model of working modes is distributed with the power split mode and the pure electric drive mode, and the second layer of the hierarchical distribution model of working modes is distributed with the pure electric drive mode, the parallel hybrid mode and the engine direct drive mode. Wherein, V20 represents a first vehicle speed threshold, and V2 represents a second vehicle speed threshold. The vehicle speed thresholds are preset based on experience, and then V20 and V2 are calibrated through later whole vehicle calibration and adjustment.

[0086] The state control requirements of the SOC of the battery pack are as shown in Figure 4 , the SOC of the battery pack should not be too high or too low, and maintaining the relative balance of SOC is very important. The driving system control method according to the embodiment of the present invention can maintain the relative balance of SOC, thereby ensuring that the vehicle has excellent power performance while maintaining high system efficiency and thus obtaining excellent fuel economy.

[0087] The method further comprises: providing buffer areas on the switching paths of each working mode, and providing buffer areas on the switching paths for starting and stopping of the engine. A certain buffer area shall be provided when switching between each working mode and the start-stop of the engine, so as to avoid frequent switching of working modes and frequent start-stop of the engine.

[0088] The method further comprises: Real-time monitoring of the battery pack's SOC.

[0089] When the current SOC of the battery pack is higher than the set upper limit SOCh and the vehicle's power demand Pr is lower than the set lower limit Prl, the engine is controlled to not work, so that the battery pack provides power to the second motor to drive the vehicle.

[0090] When the current SOC of the battery pack is lower than the set lower limit SOCl, or when the current SOC of the battery pack is between the set upper and lower limits SOCh and SOCl and the vehicle's required power Pr is between the set upper and lower limits Prh and Prl, or when the vehicle's required power Pr is higher than the set upper limit Prh, the engine is controlled to operate, making the engine the primary 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 formula for determining the operating parameters of each component under the power split mode, thereby determining the operating state of the two motors.

[0091] When the current SOC of the battery pack is higher than the set upper limit SOCh and the vehicle power demand Pr is between the set upper and lower limits Prh and Prl, or when the current SOC of the battery pack is between the set upper and lower limits SOCh and SOCl and the vehicle power demand Pr is lower than the set lower limit Prl, a transition zone is set to avoid frequent switching of operating modes and frequent engine start-stop, so that the operating mode of the hybrid drive system remains the operating mode of the previous moment (referred to as maintaining the previous mode).

[0092] The method further includes: In the power split mode of the hybrid drive system, when the engine starts, if the engine demand power Per is lower than the minimum power value Pemin on the engine's minimum fuel consumption line, the engine is controlled to operate at the minimum power value Pemin; if the engine demand power Per is higher than the maximum power value Pemax on the engine's minimum fuel consumption line, the engine is controlled to operate at the maximum power value Pemax; if the engine demand power Per is between the maximum power value Pemax and the minimum power value Pemin on the engine's minimum fuel consumption line, the engine is controlled to operate on its minimum fuel consumption line; where the engine demand power Per is equal to the vehicle demand power Pr + loss power + accessory power.

[0093] The method further includes: In engine direct drive mode or parallel hybrid mode, when the engine power demand Per is lower than the minimum power value Pemin on the engine's minimum fuel consumption line, the engine is controlled to operate at the minimum power value Pemin; when the engine power demand Per is higher than the maximum power value Pemax on the engine's minimum fuel consumption line, the engine is controlled to operate at the maximum power value Pemax; when the engine power demand Per is between the maximum power value Pemax and the minimum power value Pemin on the engine's minimum fuel consumption line, the engine is controlled to operate at its minimum fuel consumption line Peopt.

[0094] When the engine power demand Per is higher than the engine's minimum fuel consumption line Peopt, and the current SOC of the battery pack is greater than the set lower limit SOCl, the hybrid drive system is switched to the parallel boost mode of the parallel hybrid mode; when the engine power demand Per is lower than the engine's minimum fuel consumption line Peopt, and the current SOC is less than the set upper limit SOCh, the hybrid drive system is switched to the parallel power generation mode of the parallel hybrid mode.

[0095] In the third embodiment, the specific mode switching conditions are shown in Table 3: Table 3 Fourth embodiment Figure 8 The hybrid drive system shown is a fourth embodiment of the present invention. The difference from the first embodiment is that it further includes a third engagement disconnection device 80, which is located between the second end of the first engagement disconnection device 3 and the planetary carrier 43.

[0096] The engagement and disengagement of the third engagement / disengagement device 80 enables the connection and disconnection of the planet carrier 43 and the sun gear 41. When the third engagement / disengagement device 80 is engaged, the planet carrier 43 and the sun gear 41 are connected, 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 / disengagement device 80 is disengaged, the planet carrier 43 and the sun gear 41 are disconnected, and the speed ratio of the planetary gear mechanism 4 is not 1.

[0097] In this embodiment, 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.

[0098] When the first engagement disconnection device 3 is disconnected and the third engagement disconnection device 80 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 pure electric drive mode.

[0099] When the first engagement disconnection device 3 is disconnected and the third engagement disconnection device 80 is disconnected, the engine 1 drives the first motor 2 to generate electricity. All or part of the electrical energy generated by the first motor 2 is provided to the second motor 5. The second motor 5 drives the hybrid drive system to enter the power split mode.

[0100] When the first engagement / disengagement device 3 is disengaged and the third engagement / disengagement 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, and the first motor 2 is driven, generates electricity, or idles. The hybrid drive system enters parallel hybrid mode 1. When the first engagement / disengagement device 3 is engaged and the third engagement / disengagement device 80 is disengaged, the engine 1 is driven, the second motor 5 is driven or generates electricity, the first motor 2 does not work, and the hybrid drive system enters parallel hybrid mode 2.

[0101] When the first engagement disconnection device 3 is disengaged and the third engagement disconnection device 80 is engaged, the engine 1 is driven, the first motor 2 idles, the second motor 5 idles, and the hybrid drive system enters engine direct drive mode 1. When the first engagement disconnection device 3 is engaged and the third engagement disconnection device 80 is disengaged, the engine 1 is driven, the first motor 2 is not working, the second motor 5 idles, and the hybrid drive system enters engine direct drive mode 2.

[0102] When the vehicle is parked, the parking gear 30 is locked, the first engagement disconnection device 3 is disconnected, the third engagement disconnection device 80 is disconnected, the second motor 5 is not working, the engine 1 drives the first motor 2 to generate electricity, and the hybrid drive system enters the parking power generation mode.

[0103] The parallel hybrid mode includes a parallel 1st gear assist mode, a parallel 1st gear generator mode, a parallel 2nd gear assist mode, and a parallel 2nd gear generator mode. When the first engagement / disengagement device 3 is disengaged and the third engagement / disengagement device 80 is engaged, the engine 1 is driven, the second motor 5 is driven, and the first motor 2 is driven, generator, or idles, the hybrid drive system enters the parallel 1st gear assist mode. When the first engagement / disengagement device 3 is disengaged and the third engagement / disengagement device 80 is engaged, the engine 1 is driven, the second motor 5 generates electricity, and the first motor 2 is driven, generator, or idles, the hybrid drive system enters the parallel 1st gear generator mode. When the first engagement / disengagement device 3 is engaged and the third engagement / disengagement device 80 is disengaged, the engine 1 is driven, the second motor 5 generates electricity, and the first motor 2 does not operate, the hybrid drive system enters the parallel 2nd gear assist mode. When the first engagement / disengagement device 3 is engaged and the third engagement / disengagement device 80 is disengaged, the engine 1 is driven, the second motor 5 generates electricity, and the first motor 2 does not operate, the hybrid drive system enters the parallel 2nd gear generator mode.

[0104] The hybrid drive system has braking energy recovery modes in pure electric drive mode, braking energy recovery modes in power split mode, braking energy recovery modes in parallel hybrid 1st gear mode, braking energy recovery modes in parallel hybrid 2nd gear mode, braking energy recovery modes in engine direct drive 1st gear mode, and braking energy recovery modes in engine direct drive 2nd gear mode.

[0105] When the vehicle brakes in the pure electric drive mode, the first engagement disconnection device 3 is disconnected, the third engagement disconnection device 80 is disconnected, the second motor 5 is subjected to reverse torque to decelerate and 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.

[0106] When the vehicle brakes in the power split mode, the first engagement disconnection device 5 is disconnected, the third engagement disconnection device 80 is disconnected, the second motor 5 is decelerated and generates electricity under reverse torque, the engine 1 drives the first motor 2 to generate electricity, and the hybrid drive system enters the braking energy recovery mode under the power split mode.

[0107] When the vehicle brakes in the parallel hybrid 1st gear mode, the first engagement disconnection device 3 is disconnected, the third engagement disconnection device 80 is engaged, the engine 1 is driven, the second motor 5 is decelerated and generates electricity under reverse torque, 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.

[0108] When the vehicle brakes in the parallel hybrid 2-speed mode, the first engagement disconnection device 3 engages, the third engagement disconnection device 80 disengages, the engine 1 drives, the second motor 5 is decelerated and generates electricity under reverse torque, the first motor 2 does not work, and the hybrid drive system enters the braking energy recovery mode in the parallel hybrid 2-speed mode.

[0109] When the vehicle brakes in the engine direct drive 1st gear mode, the first engagement disconnection device 3 is disconnected, the third engagement disconnection device 80 is engaged, the engine 1 is driven, the second motor 5 is decelerated and generates electricity under reverse torque, the first motor 2 generates electricity or idles, and the hybrid drive system enters the brake energy recovery mode in the engine direct drive 1st gear mode.

[0110] When the vehicle brakes in the engine direct drive 2nd gear mode, the first engagement disconnection device 3 engages, the third engagement disconnection device 80 disengages, the engine 1 drives, the second motor 5 receives reverse torque to decelerate and generate electricity, the first motor 2 does not work, and the hybrid drive system enters the brake energy recovery mode in the engine direct drive 2nd gear mode.

[0111] In this embodiment, the control for each driving mode is shown in Table 4 below: Table 4 In Table 4, " / " indicates that it is not working.

[0112] Fifth embodiment See Figures 9 to 12 The fifth embodiment of the present invention also provides a drive system control method based on the hybrid drive system of the fourth embodiment, which differs from the drive system control method of the third embodiment in that: The working mode hierarchical distribution model has three layers, the layering condition between the first layer and the second layer of the working mode hierarchical distribution model is V10<V1, and the layering condition between the second layer and the third layer of the working mode hierarchical distribution model is V20>V2; the parallel hybrid mode includes a 1st-gear parallel hybrid mode and a 2nd-gear parallel hybrid mode, and the direct engine drive mode includes a 1st-gear direct engine drive mode and a 2nd-gear direct engine drive mode; the power split mode and the pure electric drive mode are distributed on the first layer of the working mode hierarchical distribution model, the pure electric drive mode, the 1st-gear parallel hybrid mode and the 1st-gear direct engine drive mode are distributed on the second layer of the working mode hierarchical distribution model, and the pure electric drive mode, the 2nd-gear parallel hybrid mode and the 2nd-gear direct engine drive mode are distributed on the third layer of the working mode hierarchical distribution model. Wherein, V20 represents a first vehicle speed threshold, V2 represents a second vehicle speed threshold, V10 represents a third vehicle speed threshold, and V1 represents a fourth vehicle speed threshold. The vehicle speed thresholds are preset according to experience, and then V20, V10, V1 and V2 are calibrated through later whole vehicle calibration and tuning.

[0113] In addition, an embodiment of the present invention further provides a vehicle, which includes the hybrid power drive system of the foregoing embodiments.

[0114] The above description is only a preferred embodiment of the present invention, and is not used to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A hybrid power drive system, characterized in that, It includes an engine, a first motor, a first engagement / disengagement device, a planetary gear mechanism, a second motor, a first shaft, a second shaft, an intermediate shaft, an intermediate shaft gear, a main reducer drive gear, a main reducer driven gear, a motor drive gear, a parking gear, and a differential. The intermediate shaft gear and the main reduction drive gear are mounted on the intermediate shaft. The main reduction driven gear is mounted on the differential housing and meshes with the main reduction drive gear. The motor drive gear and the parking gear are mounted on the second shaft. The motor drive gear meshes with the intermediate shaft gear. One end of the second shaft is connected to the rotor of the second motor. Parking can be achieved by locking the parking gear. The planetary gear mechanism includes a sun gear, planet gears, a planet 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 planet carrier. The ring gear is provided with an external gear that meshes with the intermediate shaft gear. The first engagement / disengagement device is connected between the sun gear and the stationary component, and is used to selectively engage or disengage the sun gear and the stationary component; The hybrid drive system has a parallel hybrid mode. When the first engagement / disengagement device is engaged, the engine drives, and the second motor drives or generates electricity. When the first motor is not working, the hybrid drive system enters the parallel hybrid mode. The first end of the first engagement disconnection device is connected to the stationary component, and the second end of the first engagement disconnection device is connected to the first shaft; It also includes a second engagement disconnection device. The first shaft includes a first shaft segment and a second shaft segment that are coaxial and spaced apart from each other. The first end of the first engagement disconnection 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 engagement disconnection device is connected between the other end of the first shaft segment and the second end of the first engagement disconnection device. The second shaft segment is connected between the second end of the first engagement disconnection device and the sun gear.

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

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

4. The hybrid drive system according to claim 1, characterized in that, The first motor, the first engagement / disengagement device, the planetary gear mechanism, and the engine are arranged sequentially 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 drive gear, and the parking gear are arranged sequentially 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 external gear of the gear ring is smaller than the diameter of the intermediate shaft gear.

7. 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, an engine direct drive mode, and a parking power generation mode. When the first engagement disconnection device is disconnected and the second engagement disconnection device is disconnected, the second motor drives the engine, the first motor stops working, and the hybrid drive system enters pure electric drive mode. The first engagement disconnection device is disconnected, the second engagement disconnection device is engaged, the engine drives the first motor to generate electricity, all or part of the electrical energy generated by the first motor is provided to the second motor, the second motor drives, and the hybrid drive system enters the power split mode. When the first engagement / disengagement device engages and the second engagement / disengagement device disengages, the engine is driven, the first motor is not working, the second motor is idling, and the hybrid drive system enters engine direct drive mode. When the vehicle is parked, the parking gear is locked, the first engagement disconnection device is disengaged, the second engagement disconnection device is engaged, the second motor is not working, the engine drives the first motor to generate electricity, and the hybrid drive system enters the parking power generation mode.

8. The hybrid drive system according to claim 7, characterized in that, The parallel hybrid mode includes a parallel assist mode and a parallel power generation mode; When the first engagement / disengagement device engages and the second engagement / disengagement device disengages, the engine drives, the second motor drives, the first motor does not work, and the hybrid drive system enters parallel assist mode. When the first engagement / disengagement device engages and the second engagement / disengagement device disengages, the engine drives, the second motor generates electricity, the first motor does not work, and the hybrid drive system enters parallel power generation mode.

9. The hybrid drive system according to claim 7, 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 disconnection device is disconnected, the second engagement 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 the braking energy recovery mode in the pure electric drive mode. When the vehicle brakes in the power split mode, the first engagement disconnection device is disconnected and the second engagement disconnection device is engaged. The second motor is decelerated and generates electricity under reverse torque. The engine drives the first motor to generate electricity at the same time. 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 engagement disconnection device engages, the second engagement disconnection device disengages, the second motor is decelerated and generates electricity under reverse torque, the engine drives the motor, 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 disconnection device engages, the second engagement disconnection device disengages, the second motor is decelerated and generates electricity under reverse torque, the engine drives, the first motor does not work, and the hybrid drive system enters the brake energy recovery mode in the engine direct drive mode.

10. A vehicle, characterized in that, Includes the hybrid drive system according to any one of claims 1-9.

11. A drive system control method, characterized in that, Based on the hybrid drive system according to any one of claims 1-9, the method comprises: A hierarchical distribution model of the operating modes of the hybrid drive system is established; wherein, the hybrid drive system has at least a pure electric drive mode, a power split mode, a parallel hybrid mode, and an engine direct drive mode; The switching between the pure electric drive mode, power split mode, parallel hybrid mode and engine direct drive mode is performed according to the hierarchical distribution model of the working mode.

12. The drive system control method according to claim 11, characterized in that, The hierarchical distribution model of the working mode has two layers. The hierarchical distribution condition of the first and second layers of the working mode is V20. <V2; When V≤V20, the hierarchical distribution model of the working mode is in the first layer; when the current vehicle speed V≥V2, the hierarchical distribution model of the working mode is in the second layer. Where V20 represents the first vehicle speed threshold, V2 represents the second vehicle speed threshold, and V represents the current vehicle speed; The first layer of the hierarchical distribution model of the working mode includes the power split mode and the pure electric drive mode, and the second layer of the hierarchical distribution model of the working mode includes the pure electric drive mode, the parallel hybrid mode and the engine direct drive mode.

13. The drive system control method according to claim 11, characterized in that, The method further includes: A buffer zone is set on the switching path of each working mode, and a buffer zone is set on the engine start and stop switching path.

14. The drive system control method according to claim 11, characterized in that, The method further includes: Real-time monitoring of the battery pack's state of charge (SOC); 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 to not work, so that the battery pack provides power to the second motor to drive the vehicle. 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 can drive the vehicle as the main power source. When the current SOC of the battery pack is higher than the set upper limit SOCh and the vehicle power demand Pr is between the set upper and lower limits Prh and Prl, or when the current SOC of the battery pack is between the set upper and lower limits SOCh and SOCl and the vehicle power demand Pr is lower than the set lower limit Prl, a transition zone is set to keep the hybrid drive system in the operating mode of the previous moment.

15. The drive system control method according to claim 14, 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's minimum fuel consumption line, the engine is controlled to operate at the minimum power value Pemin; when the engine demand power Per is higher than the maximum power value Pemax on the engine's minimum fuel consumption line, the engine is controlled to operate at the maximum power value Pemax; when the engine demand power Per is between the maximum power value Pemax and the minimum power value Pemin on the engine's minimum fuel consumption line, the engine is controlled to operate on its minimum fuel consumption line; where the engine demand power Per is equal to the vehicle demand power Pr + loss power + accessory power.

16. The drive system control method according to claim 14, characterized in that, The method further includes: In engine direct drive mode or parallel hybrid mode, when the engine power demand Per is lower than the minimum power value Pemin on the engine's minimum fuel consumption line, the engine is controlled to operate at the minimum power value Pemin; when the engine power demand Per is higher than the maximum power value Pemax on the engine's minimum fuel consumption line, the engine is controlled to operate at the maximum power value Pemax; when the engine power demand Per is between the maximum power value Pemax and the minimum power value Pemin on the engine's minimum fuel consumption line, the engine is controlled to operate at its minimum fuel consumption line Peopt; where the engine power demand Per is equal to the vehicle power demand Pr + loss power + accessory power; When the engine power demand Per is higher than the engine's minimum fuel consumption line Peopt, and the current SOC of the battery pack is greater than the set lower limit SOCl, the hybrid drive system is switched to the parallel boost mode of the parallel hybrid mode; when the engine power demand Per is lower than the engine's minimum fuel consumption line Peopt, and the current SOC is less than the set upper limit SOCh, the hybrid drive system is switched to the parallel power generation mode of the parallel hybrid mode.

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