Hybrid drive system and vehicle

Abstract

The present disclosure relates to a hybrid drive system and a vehicle. The hybrid drive system comprises an engine, a generator, a drive motor and a controller. The controller is connected to the engine, the generator and the drive motor respectively, and is configured to control the drive motor to increase torque when the generator unloads torque during a switching process from a dual-motor drive mode to an engine direct drive mode, and to control the drive motor to decrease torque when the engine loads torque, so that the total output torque of the system is equal to the total demand torque, and the total demand torque is constant. During the switching process, the generator starts the engine by transferring torque from the generator to the drive motor when the generator unloads torque, and the drive motor needs to bear the torque output during the time when the corresponding torque is transferred from the generator to the engine output. In this way, the total output torque of the system during the mode switching process is equal to the total demand torque, so as to meet the power demand of the vehicle and improve the driving experience.

Description

Technical Field

[0001] This disclosure relates to the field of hybrid technology, and more specifically, to a hybrid drive system and vehicle. Background Technology

[0002] With the development of electric drive technology and the improvement of charging infrastructure, hybrid vehicles are increasingly relying more on electric power while reducing the use of the internal combustion engine. A typical series-parallel architecture enables efficient operation across all scenarios: high battery level uses pure electric mode, low battery level and low speed uses series mode, and high speed uses engine direct drive mode. Hybrid drive systems typically include single-motor drive mode, dual-motor drive mode, engine direct drive mode, and series mode, switching modes according to the vehicle's power demands. Ensuring adequate power during mode switching is crucial for enhancing the driving experience. Summary of the Invention

[0003] In order to overcome the problems existing in the related technologies, this disclosure provides a hybrid power drive system and vehicle.

[0004] To achieve the above objectives, in a first aspect, this disclosure provides a hybrid power drive system, including: an engine, a generator, a drive motor, and a controller;

[0005] The controller is connected to the engine, generator, and drive motor respectively. During the process of switching the system from dual-motor drive mode to engine direct drive mode, when the generator unloads torque, the controller controls the drive motor to increase torque, and when the engine loads torque, the controller controls the drive motor to decrease torque, so that the total output torque of the system is equal to the total demand torque, and the total demand torque is constant.

[0006] Optionally, the system further includes: a shifting mechanism, a differential, a clutch, a drive gear, and a generator gear;

[0007] The generator is selectively connected to the drive gear or the generator gear via the shifting mechanism;

[0008] The drive gear is connected to the engine via the clutch;

[0009] The generator gear is connected to the engine;

[0010] The differential has a first end connected to the clutch, a second end connected to the drive motor, and a third end connected to the wheel.

[0011] Optionally, the controller is connected to the shifting mechanism and the clutch respectively, and is used for:

[0012] In response to detecting that the system meets the condition for switching from the dual-motor drive mode to the engine direct drive mode, the generator is controlled to unload torque and the drive motor to increase torque so that the total output torque is equal to the total required torque of the wheels, wherein the shifting mechanism is connected to the drive gear.

[0013] If the torque of the generator is unloaded to zero, the shift mechanism is controlled to be in the neutral position, the generator is controlled to output reverse torque, and when the generator speed is less than or equal to the first preset speed, the generator is controlled to unload the reverse torque.

[0014] When the generator speed is zero, the shifting mechanism is controlled to connect with the generator gear, and the generator is controlled to apply torque to start the engine;

[0015] When the difference between the engine speed and the target speed is greater than or equal to the second preset speed, the generator is controlled to unload torque, wherein the target speed is determined based on the vehicle speed and the second preset speed is less than zero;

[0016] When the engine speed reaches the target speed, the engine is started, the clutch is engaged, the engine loads torque, and the drive motor reduces torque, so that the total output torque equals the total required torque.

[0017] Optionally, the controller is further configured to control the system to operate in the engine direct drive mode when the engine torque reaches a preset torque.

[0018] Optionally, the controller is used to:

[0019] When the engine torque reaches the preset torque, the first torque of the engine and the second torque of the drive motor are determined based on the current total torque demand of the wheels.

[0020] The engine is controlled to output the first torque, and the drive motor is controlled to output the second torque.

[0021] Optionally, the controller is used to determine the drive motor torque and engine torque corresponding to the current total demand torque according to the pre-established correspondence between the total demand torque, drive motor torque and engine torque, and use them as the second torque and the first torque, respectively. The system has the highest driving efficiency when the engine and the drive motor distribute torque according to the correspondence.

[0022] Optionally, the controller is also configured to control the shift mechanism to be in the neutral position after the engine is started.

[0023] Optionally, the controller is further configured to control the difference between the engine speed and the wheel speed within a preset speed range when the engine speed reaches the target speed.

[0024] Optionally, the controller is further configured to:

[0025] When the system is in the dual-motor drive mode, if the remaining battery power is less than a first preset power threshold and the vehicle speed is greater than a preset speed, or if the remaining battery power is less than a second preset power threshold and the total power demand is greater than a preset power threshold, then the system is determined to meet the conditions, wherein the battery is connected to the generator and the drive motor respectively.

[0026] Secondly, this disclosure provides a vehicle, including:

[0027] A hybrid power drive system, wherein the hybrid power drive system is the hybrid power drive system provided in the first aspect of this disclosure; and

[0028] wheel.

[0029] In the above technical solution, during the switching process from dual-motor drive mode to engine direct drive mode of the hybrid drive system, when the generator unloads torque, the torque from the generator is transferred to the drive motor to start the engine. The drive motor needs to withstand the torque output during the time it takes for the generator torque to transfer to the engine's output torque. This ensures that the total output torque of the hybrid drive system equals the total required torque during mode switching, meeting the vehicle's power needs and improving the driving experience.

[0030] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0031] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0032] Figure 1 This is a block diagram illustrating a hybrid drive system according to an exemplary embodiment.

[0033] Figure 2 This is a block diagram illustrating a hybrid drive system according to another exemplary embodiment.

[0034] Figure 3 This is a schematic diagram of a hybrid power drive system according to an exemplary embodiment.

[0035] Figure 4 This is a schematic diagram of energy transfer in a single-motor drive mode according to an exemplary embodiment.

[0036] Figure 5 This is a schematic diagram illustrating energy transfer in a dual-motor drive mode according to an exemplary embodiment.

[0037] Figure 6 This is a schematic diagram illustrating a series mode of energy transfer according to an exemplary embodiment.

[0038] Figure 7 This is a schematic diagram illustrating energy transfer in a direct-drive mode of an engine according to an exemplary embodiment.

[0039] Figure 8 This is a schematic diagram of energy transfer in a three-power-source mode according to an exemplary embodiment.

[0040] Figure 9 This is a schematic diagram illustrating energy transfer in a dual-motor feedback mode according to an exemplary embodiment.

[0041] Figure 10 This is a flowchart illustrating a method for switching from a dual-motor drive mode to an engine direct drive mode according to an exemplary embodiment.

[0042] Figure 11 This is a timing diagram illustrating a switching from a dual-motor drive mode to an engine direct drive mode according to an exemplary embodiment.

[0043] Figure 12 This is a schematic diagram illustrating the energy transfer of a starting engine according to an exemplary embodiment.

[0044] Explanation of reference numerals in the attached figures

[0045] 1 engine 2 generator

[0046] 3 drive motors 4 controllers

[0047] 5. Gear shifting mechanism 6. Differential

[0048] 7. Clutch 8. Drive gear

[0049] 9 Generator gear 10 First motor shaft

[0050] 11. Engine second gear drive gear; 12. Engine second gear driven gear

[0051] 13 Engine first gear drive gear 14 Intermediate shaft

[0052] 15 Second motor shaft 16 Second motor reduction gear shaft

[0053] 17 Second motor, first stage reduction driven gear, 19 shaft gear

[0054] 18 Second motor secondary reduction drive gear; 20 Intermediate shaft reduction drive gear

[0055] 21 Main reduction gear 22 Engine output shaft

[0056] 100 hybrid drive system 200 wheels

[0057] 300 battery Detailed Implementation

[0058] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0059] Figure 1 This is a block diagram illustrating a hybrid power drive system according to an exemplary embodiment. Figure 1 As shown, the hybrid drive system 100 includes an engine 1, a generator 2, a drive motor 3, and a controller 4.

[0060] The controller 4 is connected to the engine 1, the generator 2 and the drive motor 3 respectively. During the process of switching the hybrid drive system 100 from the dual-motor drive mode to the engine direct drive mode, when the generator 2 unloads torque, the controller controls the drive motor 3 to increase the torque, and when the engine 1 loads torque, the controller controls the drive motor 3 to decrease the torque, so that the total output torque of the hybrid drive system 100 is equal to the total demand torque, and the total demand torque is constant.

[0061] In this disclosure, the hybrid drive system can adopt different operating modes according to different operating conditions of the vehicle, which may include single motor drive mode, dual motor drive mode, series mode, parallel mode (i.e., engine direct drive mode), three power source mode, and dual motor regenerative mode (i.e., energy recovery mode).

[0062] When the hybrid drive system is in dual-motor drive mode, if the conditions for switching to engine direct drive mode are met, the hybrid drive system is controlled to switch from dual-motor drive mode to engine direct drive mode. To ensure the vehicle's power requirements are met during mode switching and to improve the driving experience, the total output torque of the hybrid drive system must equal the total required torque. Therefore, with a fixed total required torque, when generator 2 unloads torque, drive motor 3 increases torque, and when engine 1 loads torque, drive motor 3 decreases torque.

[0063] In the above technical solution, during the switching process from dual-motor drive mode to engine direct drive mode of the hybrid drive system, when the generator unloads torque, the torque from the generator is transferred to the drive motor to start the engine. The drive motor needs to withstand the torque output during the time it takes for the generator torque to transfer to the engine's output torque. This ensures that the total output torque of the hybrid drive system equals the total required torque during mode switching, meeting the vehicle's power needs and improving the driving experience.

[0064] In one implementation, such as Figure 2 As shown, the hybrid drive system may further include: a shift mechanism 5, a differential 6, a clutch 7, a drive gear 8, and a generator gear 9.

[0065] like Figure 2 As shown, generator 2 is selectively connected to drive gear 8 or generator gear 9 via shift mechanism 5; drive gear 8 is connected to engine 1 via clutch 7; generator gear 9 is connected to engine 1; differential 6 has a first end connected to clutch 7, a second end connected to drive motor 3, and a third end used to connect to wheel 200; controller 4 is connected to shift mechanism 5 and clutch 7 respectively; in addition, generator 2 and drive motor 3 are respectively connected to battery 300.

[0066] Specifically, such as Figure 3 As shown (controller 4 not shown), the hybrid drive system also includes a first motor shaft 10, an engine second-speed drive gear 11, an engine second-speed driven gear 12, an engine first-speed drive gear 13, an intermediate shaft 14, a second motor shaft 15, a second motor reduction gear shaft 16, a second motor first-speed reduction driven gear 17, a second motor second-speed reduction drive gear 18, a shaft gear 19, an intermediate shaft reduction drive gear 20 fixedly connected to the intermediate shaft 14, a main reduction gear 21 disposed on the differential 6, and an engine output shaft 22.

[0067] like Figure 3 As shown, the generator gear 9 and the drive gear 8 are loosely fitted on the first motor shaft 10. The shifting mechanism 5 is set on the first motor shaft 10 and located between the generator gear 9 and the drive gear 8. The shifting mechanism 5 selectively engages with either the generator gear 9 or the drive gear 8. The first motor shaft 10 is connected to the generator 2.

[0068] In this disclosure, generator 2 is used to connect to battery 300. Figure 3 (not shown in the image), the shifting mechanism 5 can be a synchronizer (such as...). Figure 3(As shown) or a gear shifting mechanism, the output end of the generator 2 is selectively connected to the generator gear 9 or the drive gear 8 via the gear shifting mechanism 5. Specifically, when it is necessary to start the engine 1 or when the engine 1 needs to drive the generator 2 to generate electricity, the gear shifting mechanism 5 can engage with the generator gear 9; when the generator 2 needs to drive the wheels, the gear shifting mechanism 5 can engage with the drive gear 8.

[0069] like Figure 3 As shown, the engine output shaft 22 is connected to the engine 1, the second gear drive gear 11 is loosely fitted on the engine output shaft 22, the first gear drive gear 13 is fixedly connected to the engine output shaft 22, the clutch 7 is set on the engine output shaft 22, the driving end of the clutch 7 is connected to the engine 1, and the driven end of the clutch 7 is connected to the second gear drive gear 11.

[0070] like Figure 3 As shown, the second-gear driven gear 12 of the engine is connected to the intermediate shaft 14. The intermediate shaft 14 can be connected to the differential 6 via the intermediate shaft reduction drive gear 20 fixedly connected to the intermediate shaft 14 and the main reduction gear 21 set on the differential 6. The second-gear driven gear 12 of the engine can be fixedly connected to the intermediate shaft 14 (e.g., Figure 3 (As shown), it can also be loosely connected in the intermediate shaft 14. This disclosure does not specifically limit the connection method between the engine second gear driven gear 12 and the intermediate shaft 14. The engine second gear driving gear 11 meshes with the drive gear 8 and the engine second gear driven gear 12 respectively, and the engine first gear driving gear 13 meshes with the generator gear 9.

[0071] like Figure 3 As shown, the driven gear 17 of the first-stage reduction gear of the second motor and the driving gear 18 of the second-stage reduction gear of the second motor are fixedly connected to the reduction gear shaft 16 of the second motor, and the shaft gear 19 is fixedly connected to the shaft 15 of the second motor. The shaft 15 of the second motor is connected to the drive motor 3. The driven gear 17 of the first-stage reduction gear of the second motor meshes with the shaft gear 19, and the main reduction gear 21 meshes with the intermediate shaft reduction driving gear 20 and the driving gear 18 of the second-stage reduction gear of the second motor, respectively. The drive motor 3 can be mechanically connected to the differential 6 via the shaft gear 19, the driven gear 17 of the first-stage reduction gear of the second motor, the driving gear 18 of the second-stage reduction gear of the second motor, and the main reduction gear 21 in sequence. The drive motor 3 is used to connect to the battery 300. Figure 3 (Not shown in the image).

[0072] In one implementation, such as Figure 3As shown, the generator gear 9, the engine first gear drive gear 13, the intermediate shaft reduction drive gear 20, the main reduction gear 21, and the second motor second-stage reduction drive gear 18 are arranged axially overlapping (i.e., aligned and spaced radially). The drive gear 8, the engine second gear drive gear 11, the engine second gear driven gear 12, the second motor first-stage reduction driven gear 17, and the shaft gear 19 are also arranged axially overlapping. In this way, the hybrid drive system has only two rows of gears, which effectively compresses the axial space and shortens the axial dimension of the hybrid drive system, facilitating vehicle installation and layout. This results in a simple and compact structure and a simple assembly process for the hybrid drive system.

[0073] Hybrid drive systems can adopt different operating modes depending on the vehicle's operating conditions. These modes can include single-motor drive mode, dual-motor drive mode, series mode, engine direct drive mode, three-power source mode, and dual-motor regenerative mode.

[0074] When the hybrid drive system is operating in pure electric mode under low to medium load, the system is in single-motor drive mode, such as... Figure 4 As shown, the shift mechanism 5 is in the neutral position, the clutch 7 is disengaged, the drive motor 3 drives the wheel 200 alone, and the engine 1 and generator 2 are both stationary (i.e. not working).

[0075] When the hybrid drive system is operating in pure electric mode under high load, the system is in dual-motor drive mode, such as... Figure 5 As shown, the shift mechanism 5 is in the left position and connected to the drive gear 8, the clutch 7 is disengaged, the generator 2 and the drive motor 3 jointly drive the wheel 200, and the engine 1 remains stationary.

[0076] When the hybrid drive system is in pure electric drive mode, it can select either single-motor drive mode or dual-motor drive mode according to the load size. At the same time, engine 1 will not be towed (engine 1 is stationary). In this way, the system can reduce the power of a single motor and reduce the motor capacity without sacrificing power, thereby reducing system costs and improving drive efficiency.

[0077] When the hybrid drive system is running in series mode, such as Figure 6 As shown, the shift mechanism 5 is in the right position, the clutch 7 is disengaged, and the engine 1 engages with the generator gear 9 via the engine first gear drive gear 13 to drive the generator 2 to generate electricity. When the power demand of the drive motor 3 is greater than the power output of the generator 2, the battery 300 discharges, and the drive motor 3 drives the wheels 200; when the power demand of the drive motor 3 is less than the power output of the generator 2, the generator 2 provides power to the drive motor 3 to drive the wheels 200, and the excess power is used to charge the battery 300.

[0078] In the dual-motor drive mode, when the generator 2 drives the wheel 200, it uses the drive gear 8 to transmit power. When the engine 1 and the generator 2 work in series (i.e., in series mode), the power of the engine 1 is transmitted through the generator gear 9. That is, the drive path and the power generation path of the generator 2 are different. In this way, the speed ratio matching of the generator 2 in pure electric drive and series power generation is more flexible and better.

[0079] When the hybrid drive system is in engine direct drive mode, such as Figure 7 As shown, the shift mechanism 5 is in the neutral position, the generator 2 is stationary, the clutch 7 is engaged, and the engine 1 transmits power to the differential 6 in sequence through the engine second gear drive gear 11, the engine second gear driven gear 12, the intermediate shaft reduction drive gear 20, and the main reduction gear 21.

[0080] When the hybrid drive system is in engine direct drive mode, the shift mechanism 5 is in the neutral position, the generator 2 is disconnected from the engine 1, there is no no-load loss, and the generator drag loss is reduced.

[0081] When the hybrid drive system is operating in three-power source mode, such as Figure 8 As shown, the shift mechanism 5 is in the left position, the clutch 7 is engaged, the generator 2 is connected to the drive gear 8 through the shift mechanism 5, and transmits power to the differential 6 through the engine second gear drive gear 11, engine second gear driven gear 12, intermediate shaft reduction drive gear 20 and main reduction gear 21, so that the generator 2, engine 1 and drive motor 3 jointly drive the wheels 200.

[0082] When the hybrid drive system is running in three power source mode, the engine 1 drives the wheel path and requires clutch 7 to transmit torque, while the generator 2 drives the wheel path and does not require clutch 7 to transmit torque. Therefore, reducing the torque capacity of clutch 7 reduces the cost of clutch 7 and improves the reliability of clutch 7.

[0083] When the vehicle brakes, the hybrid drive system enters a dual-motor regenerative braking mode, such as... Figure 9 As shown, when engine 1 is shut down, differential 6 absorbs the kinetic energy during braking and transfers it to generator 2 and drive motor 3. The two motors generate negative torque to charge battery 300, thus realizing simultaneous energy recovery of generator 2 and drive motor 3, improving energy recovery capability, and thereby improving energy utilization.

[0084] Hybrid drive systems switch modes according to the vehicle's power demands. Ensuring the vehicle's power requirements are met during mode switching is crucial for enhancing the driving experience. The following section describes in detail the method for switching from dual-motor drive mode to engine direct drive mode.

[0085] Specifically, the controller 4 mentioned above is used to switch from the dual-motor drive mode to the engine direct drive mode in the following way:

[0086] In response to the detection that the system meets the conditions for switching from dual-motor drive mode to engine direct drive mode, the generator 2 is controlled to unload torque and the drive motor 3 to increase torque so that the total output torque is equal to the total required torque of the wheels 200. In this case, the shift mechanism 5 is connected to the drive gear 8 (i.e., the shift mechanism 5 is located in the left position).

[0087] If the torque of generator 2 is unloaded to zero, the shift mechanism 5 is placed in the neutral position, and generator 2 is controlled to output reverse torque. When the speed of generator 2 is less than or equal to the first preset speed, generator 2 is controlled to unload reverse torque.

[0088] When the speed of generator 2 is zero, the control shift mechanism 5 is connected to the generator gear 9, and the generator 2 is controlled to load torque to start engine 1;

[0089] When the difference between the engine speed and the target speed is greater than or equal to the second preset speed, the generator 2 is controlled to unload torque. The target speed is the speed required for the clutch 7 to engage. The target speed is determined based on the vehicle speed. The second preset speed is less than zero.

[0090] When the engine speed of engine 1 reaches the target speed, control engine 1 to start, clutch 7 to engage, and control engine 1 to load torque and drive motor 3 to reduce torque so that the total output torque equals the total required torque.

[0091] When the torque of engine 1 reaches the preset torque, the control system operates in engine direct drive mode.

[0092] Specifically, the controller 4 is used to control the system to operate in engine direct drive mode in the following way: when the torque of the engine 1 reaches the preset torque, the controller determines the first torque of the engine 1 and the second torque of the drive motor 3 based on the current total torque demand of the wheels 200; the controller controls the engine 1 to output the first torque and controls the drive motor 3 to output the second torque.

[0093] In one embodiment, the controller 4 is used to determine the drive motor torque and engine torque corresponding to the current total demand torque according to the pre-established correspondence between the total demand torque, drive motor torque and engine torque, and respectively serve as the second torque and the first torque. The system has the highest driving efficiency when the engine 1 and drive motor 3 are torque-distributed according to the correspondence. That is, the above correspondence records the optimal distribution of drive motor torque and engine torque that maximizes the driving efficiency of the system when the total demand torque is constant. In this correspondence, the total demand torque = the drive motor torque corresponding to the total demand torque + the engine torque corresponding to the total demand torque.

[0094] In addition, the controller 4 is also used to control the shift mechanism 5 to be in the neutral position after the engine 1 is started. This allows the generator 2 to be disconnected from the engine 1, eliminating no-load losses and reducing generator drag losses.

[0095] In addition, to reduce wear on the clutch 7, the controller 4 is also used to control the difference between the engine speed and the wheel speed 200 within a preset speed range when the engine speed 1 reaches the target speed, so as to align the engine speed; wherein, the engine speed corresponds to the clutch input speed, and the wheel speed (i.e., the wheel end speed) corresponds to the clutch output speed. Controlling the difference between the engine speed and the wheel speed 200 within the preset speed range means controlling the speed difference between the clutch input and output ends within the preset speed range.

[0096] The controller 4 is also used to determine that the hybrid drive system meets the conditions for switching from the dual-motor drive mode to the engine direct drive mode when the hybrid drive system is in the dual-motor drive mode, if the remaining charge of the battery 300 is less than the first preset charge threshold and the vehicle speed is greater than the preset speed, or the remaining charge is less than the second preset charge threshold and the total power demand is greater than the preset power threshold.

[0097] In one implementation, if the vehicle is cruising at high speed with low battery power, as the remaining power of the battery 300 decreases, the dual-motor drive mode cannot meet the wheel-end power requirements. That is, the remaining power of the battery 300 is less than the first preset power threshold and the vehicle speed is greater than the preset speed. At this time, it is necessary to switch to engine direct drive mode.

[0098] In another implementation, if the vehicle is overtaking continuously with low battery power, as the remaining power of the battery 300 decreases, the dual-motor drive mode cannot meet the vehicle's power requirements. That is, the remaining power of the battery 300 is less than the second preset power threshold and the total power demand is greater than the preset power threshold. In order to maintain the vehicle's power, it is necessary to switch to engine direct drive mode.

[0099] The following is combined with Figure 10The flowchart shown details the process of switching from dual-motor drive mode to engine direct drive mode. Figure 10 As shown, when the hybrid drive system is in dual-motor drive mode, it is first determined whether the hybrid drive system meets the conditions for switching from dual-motor drive mode to engine direct drive mode, that is, whether to switch to engine direct drive mode. If it is determined to switch to engine direct drive mode, the torque of generator 2 is first transferred to drive motor 3 by generator unloading calculation, while keeping the wheel end torque unchanged (i.e., the total required torque is constant). This includes: generator 2 torque transfer (reducing the torque of generator 2 and correspondingly increasing the torque of drive motor 3), shift mechanism 5 returning to the right position (the generator switches from drive to power generation path), and generator speed alignment (reducing the generator speed to start engine 1). Secondly, the engine is started to drive the drive wheels by engine starting calculation, while keeping the wheel end torque unchanged. This includes: engine starting (engine 1 is started by generator 2), engine speed alignment (i.e., controlling the speed difference between the clutch input and output ends within the preset speed range), clutch 7 engaging (controlling clutch 7 engagement to achieve engine direct drive path), and engine 1 torque loading (increasing engine 1 torque and reducing drive motor 3 torque), finally achieving engine direct drive. If it is determined that the mode will not be switched to engine direct drive mode, then the determination continues to determine whether to switch to engine direct drive mode.

[0100] The following is combined with Figure 11 The timing diagram shown details the switching process from dual-motor drive mode to engine direct drive mode. Figure 11 This is an example of a timing diagram for the transition from slow acceleration driven by dual motors to direct-drive engine driving. Specifically, the transition process is divided into stages T1 to T7:

[0101] T1 phase: Dual motor drive, all system states remain unchanged;

[0102] T2 stage: The torque of generator 2 begins to be unloaded. At the same time, in order to ensure that the power of the whole vehicle meets the requirements, the torque of drive motor 3 increases. During this process, the shift mechanism 5 is still in the left position, that is, the shift mechanism 5 is connected to the drive gear 8, keeping the generator drive gear. The clutch 7 remains disengaged, that is, the engine 1 is neither driven nor generates electricity.

[0103] T3 stage: After the torque of generator 2 is completely unloaded to zero, the speed of generator 2 is at its maximum. The shift mechanism 5 is placed in the neutral position (i.e., neutral). At this time, the generator 2 is controlled to output reverse torque to reduce the speed of generator 2, in preparation for the subsequent placement of shift mechanism 5 in the right position to combine generator 2 with engine 1 which has a zero speed. When the speed of generator 2 is less than or equal to the first preset speed (i.e., the generator speed is close to zero), the reverse torque of generator 2 is unloaded. During this process, the output torque of drive motor 3 is equal to the total required torque.

[0104] T4 stage: When the speed of generator 2 drops to zero, it completes the speed alignment with engine 1. At this time, if... Figure 12 As shown, the shift mechanism 5 can be smoothly connected to the right position. After the shift mechanism 5 is successfully engaged with the generator gear 9, the torque of the generator 2 is applied to drive the engine 1 to start. During this process, the clutch 7 is not engaged and the output of the drive motor 3 is equal to the total required torque.

[0105] T5 stage: The engine speed of engine 1 increases, and when the difference between the engine speed of engine 1 and the target speed is greater than or equal to the second preset speed (i.e., the engine speed of engine 1 is close to the speed required for clutch 7 to engage), the torque of generator 1 is unloaded. During this process, clutch 7 is not engaged, and the output of drive motor 3 is equal to the total required torque.

[0106] T6 stage: After the engine speed reaches the speed required for clutch 7 to engage (i.e. target speed), the engine 1 is ignited and started, clutch 7 is engaged, and the engine 1 officially participates in the driving work to output torque. At the same time, the torque of the drive motor 3 is reduced to ensure that the power of the whole vehicle meets the requirements. Under the condition of ensuring the normal operation of the engine 1, the shift mechanism 5 is moved from the right position to the middle position, thereby disconnecting the generator 2 from the generator transmission path and reducing the drag of the generator 2.

[0107] T7 stage: After reaching the preset torque, it officially enters the engine direct drive mode, and distributes the engine torque and drive motor torque according to the most efficient distribution.

[0108] In addition, this disclosure also provides a vehicle, including:

[0109] A hybrid drive system 100, wherein the hybrid drive system 100 is the hybrid drive system provided in this disclosure; and

[0110] Wheel 200.

[0111] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0112] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0113] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A hybrid power drive system, characterized in that, include: Engine (1), generator (2), drive motor (3) and controller (4); The controller (4) is connected to the engine (1), generator (2) and drive motor (3) respectively. It is used to control the drive motor (3) to increase the torque when the generator (2) unloads the torque during the process of switching the system from dual motor drive mode to engine direct drive mode, and to control the drive motor (3) to decrease the torque when the engine (1) loads the torque, so that the total output torque of the system is equal to the total demand torque, and the total demand torque is constant. The system also includes: a shift mechanism (5), a differential (6), a clutch (7), a drive gear (8), and a generator gear (9). The generator (2) is selectively connected to the drive gear (8) or the generator gear (9) via the shifting mechanism (5); The drive gear (8) is connected to the engine (1) via the clutch (7); The generator gear (9) is connected to the engine (1); The differential (6) has a first end connected to the clutch (7), a second end connected to the drive motor (3), and a third end connected to the wheel (200). The controller (4) is connected to the shifting mechanism (5) and the clutch (7) respectively, and is used for: In response to the detection that the system meets the condition of switching from the dual-motor drive mode to the engine direct drive mode, the generator (2) is controlled to unload torque and the drive motor (3) is controlled to increase torque so that the total output torque is equal to the total required torque of the wheel (200), wherein the shifting mechanism (5) is connected to the drive gear (8); If the torque of the generator (2) is unloaded to zero, the shift mechanism (5) is controlled to be in the neutral position, the generator (2) is controlled to output reverse torque, and when the speed of the generator (2) is less than or equal to the first preset speed, the generator (2) is controlled to unload the reverse torque. When the speed of the generator (2) is zero, the shift mechanism (5) is connected to the generator gear (9), and the generator (2) is loaded with torque to start the engine (1). When the difference between the engine speed (1) and the target speed is greater than or equal to the second preset speed, the generator (2) is controlled to unload torque, wherein the target speed is determined based on the vehicle speed and the second preset speed is less than zero; When the engine (1) reaches the target speed, the engine (1) is started, the clutch (7) is engaged, the engine (1) is loaded with torque, and the drive motor (3) is reduced in torque so that the total output torque is equal to the total required torque.

2. The system according to claim 1, characterized in that, The controller (4) is also used to control the system to work in the engine direct drive mode when the torque of the engine (1) reaches the preset torque.

3. The system according to claim 2, characterized in that, The controller (4) is used for: When the torque of the engine (1) reaches the preset torque, the first torque of the engine (1) and the second torque of the drive motor (3) are determined according to the current total torque demand of the wheel (200); Control the engine (1) to output the first torque, and control the drive motor (3) to output the second torque.

4. The system according to claim 3, characterized in that, The controller (4) is used to determine the drive motor torque and engine torque corresponding to the current total demand torque according to the pre-established correspondence between the total demand torque, drive motor torque and engine torque, and respectively serve as the second torque and the first torque. The system has the highest driving efficiency when the engine (1) and the drive motor (3) distribute torque according to the correspondence.

5. The system according to any one of claims 1-4, characterized in that, The controller (4) is also used to control the shift mechanism (5) to be in the neutral position after the engine (1) is started.

6. The system according to any one of claims 1-4, characterized in that, The controller (4) is also used to control the difference between the speed of the engine (1) and the speed of the wheel (200) within a preset speed range when the speed of the engine (1) reaches the target speed.

7. The system according to any one of claims 1-4, characterized in that, The controller (4) is also used for: When the system is in the dual-motor drive mode, if the remaining power of the battery (300) is less than the first preset power threshold and the vehicle speed is greater than the preset speed, or the remaining power is less than the second preset power threshold and the total power demand is greater than the preset power threshold, then the system is determined to meet the conditions, wherein the battery (300) is connected to the generator (2) and the drive motor (3) respectively.

8. A vehicle, characterized in that, include: A hybrid drive system (100), wherein the hybrid drive system (100) is a hybrid drive system according to any one of claims 1-7; and Wheel (200).

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