Hybrid power electronic control stepless speed change power driving system and method and tractor

Abstract

The invention relates to the technical field of vehicle power devices, and provides a hybrid power electronic control stepless speed change power driving system and method and a tractor. The hybrid power electronic control stepless speed change power driving system comprises a generator, a mechanical coupling device, a motor driving unit and an auxiliary motor capable of rotating forwards and backwards; the engine is connected to the auxiliary motor through a mechanical coupling device so as to provide electric energy for the motor driving unit; the power output ends of the multiple motors of the motor driving unit are connected to the mechanical coupling device, and power of the multiple motors, the auxiliary motor and the engine is coupled and output through the mechanical coupling device so as to drive wheels. By improving the structure of the power driving system, a flexible engine and motor cooperative control scheme is provided, the problems of power mismatching, low efficiency and the like in the prior art can be effectively solved, efficient operation of the tractor under different working conditions is ensured, and the stability, reliability and overall performance of the system are improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field related to vehicle power devices, and in particular to a hybrid electric-controlled continuously variable power drive system, method and tractor. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] During the operation of the tractor, it is affected by many factors, such as the contact area between the tire and the soil, soil moisture, soil viscosity, operating depth, and the working state of the agricultural machinery, which cause complex nonlinear dynamic changes in the resistance between the agricultural machinery and the land. Since these changes not only fluctuate over time, but are also significantly affected by environmental conditions, traditional transmission systems are often unable to efficiently cope with such changes, resulting in unstable working performance and low efficiency. The shifting technology of tractors usually includes traditional mechanical shifting technology (such as sliding gear shifting, meshing sleeves and synchronous shifters) and continuously variable transmission technology (such as hydraulic continuously variable transmission technology). Traditional mechanical shifting technology is usually operated manually, and fails to fully consider the working state and working environment of the tractor, which will lead to problems such as uneven shifting, loud noise, and poor reliability. In addition, mechanical shifting also has the disadvantages of complex structure and inconvenient operation.

[0004] Continuously variable transmission technology has improved the shortcomings of traditional mechanical shifting to a certain extent, especially the hydraulic continuously variable transmission (CVT) can provide a smooth shifting experience. However, the efficiency of the hydraulic transmission system is low, and the hydraulic part has problems such as complex structure, troublesome maintenance and energy loss. Therefore, although hydraulic continuously variable transmission technology has certain advantages, there is still room for optimization. Compared with the hydraulic system, the electric motor-driven continuously variable transmission technology (ECVT) has higher efficiency and lower maintenance costs. ECVT technology achieves continuously variable speed change by adjusting the opening and closing of the electromagnetic clutch through an electronic control system. This method is smoother than traditional mechanical shifting and hydraulic systems, and does not require complex mechanical components such as gears, clutches or torque converters, so it has higher reliability and lower energy loss.

[0005] However, the existing electric motor-driven continuously variable transmission technology still faces some challenges. Limited by the structure of the power drive system, the current power allocation method mainly relies on a fixed power distribution strategy, which is difficult to flexibly adjust according to actual working conditions, and at the same time, the demand for battery capacity is relatively large. Under high load conditions, the power output of the tractor power system may be insufficient. Especially when the tractor faces complex operating environments such as different soil types, humidity changes, and undulating terrain, the power demand fluctuates violently, and the existing solutions may not be able to adjust the output in time, affecting the operating efficiency. The traditional power distribution mechanism cannot accurately respond to complex operating scenarios, resulting in unbalanced power, especially in the starting, acceleration, steering and other links. The coordinated work of the motor and the engine may lag or mismatch, affecting the operating stability and power response speed of the tractor. Summary of the invention

[0006] In order to solve the above-mentioned problems, the present invention proposes a hybrid electric-controlled continuously variable power drive system, method and tractor. By improving the structure of the power drive system, a flexible coordinated control scheme for the engine and the motor is proposed, which can effectively solve the problems of power mismatch and low efficiency existing in the prior art, ensure the efficient operation of the tractor under different working conditions, and improve the stability, reliability and overall performance of the power system.

[0007] In order to achieve the above objectives, the present disclosure adopts the following technical solutions: One or more embodiments provide a hybrid electric-controlled continuously variable power drive system, comprising: a generator, a mechanical coupling device, a motor drive unit, and an auxiliary motor capable of forward and reverse rotation, which are connected in sequence; The engine is connected to the auxiliary motor through a mechanical coupling device to provide electrical energy to the motor drive unit; the power output ends of the multiple motors of the motor drive unit are connected to the mechanical coupling device, and the mechanical coupling device couples the power output of the multiple motors, the auxiliary motor and the engine to drive the wheels.

[0008] A driving control method based on the above hybrid electric-controlled continuously variable power drive system includes the following steps: Obtain vehicle operation instructions and enter electric mode when starting the vehicle; When the vehicle is in working state, it receives the PTO power output command and outputs the rotary tillage power through the electric motor; if the wheel power output needs to be less than the set threshold, it enters the engine drive and charging mode, and the engine provides the driving force for the wheel; otherwise, it enters the collaborative working mode, and the engine and the electric motor are collaboratively controlled to provide power to the wheel; When the vehicle's engine is running, in response to a battery charging request, it switches to an engine running mode to charge the battery.

[0009] A tractor adopts the above-mentioned hybrid electric-controlled continuously variable speed power drive system to provide power for the operation and wheels of the tractor.

[0010] Compared with the prior art, the present invention has the following beneficial effects: In the present disclosure, the power of the engine is divided into two parts, power generation and driving, through the mechanical coupling device and the auxiliary motor, so that the system can optimize energy utilization under different working conditions and improve fuel economy. The system is equipped with multiple electric motors, auxiliary motors and engines. The driving force source of the tractor is no longer single, but is dynamically coordinated by multiple power sources. The power output can be intelligently adjusted according to different operating requirements, achieving higher drive control accuracy and improving the flexibility of system power regulation.

[0011] The drive control method proposed in the present disclosure controls the coordinated work between the motor and the engine through precise working mode switching, and can flexibly adjust the power output under different working conditions to ensure power balance and efficient use. By real-time monitoring of vehicle load and battery power, the method can ensure that the system responds quickly and provides stable power output under complex working conditions, avoiding the lag and instability that may occur in traditional systems.

[0012] The advantages of the present disclosure and the advantages of additional aspects will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings constituting a part of the present disclosure are used to provide a further understanding of the present disclosure. The exemplary embodiments of the present disclosure and the description thereof are used to explain the present disclosure but do not constitute a limitation of the present disclosure.

[0014] Figure 1 is a schematic structural diagram of a power drive system according to Embodiment 1 of the present disclosure; Figure 2 is a flow chart of a power driving method according to Embodiment 2 of the present disclosure; Wherein: 1. first motor, 2. second motor, 3. auxiliary motor, 4. first power battery, 5. second power battery, 6. first gear; 7. Mechanical coupling device, 71. Big ring gear, 72. Second sun gear, 73. First sun gear, 74. Second planetary gear, 75. First planetary gear, 76. Planet carrier; 8. Second gear, 9. Third gear, 10. Fourth gear, 11. Fifth gear. DETAILED DESCRIPTION

[0015] The present disclosure is further described below in conjunction with the accompanying drawings and embodiments.

[0016] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present disclosure belongs.

[0017] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof. It should be noted that, in the absence of conflict, the various embodiments in the present disclosure and the features in the embodiments can be combined with each other. The embodiments will be described in detail below in conjunction with the accompanying drawings.

[0018] Example 1 In the technical solutions disclosed in one or more embodiments, Figure 1 As shown, a hybrid electric-controlled continuously variable speed power drive system comprises: an engine (Engine), a mechanical coupling device 7, an electric motor drive unit and an auxiliary motor 3 which can be rotated forward and reversely in sequence; The engine is connected to the auxiliary motor 3 through a mechanical coupling device 7 to provide electric energy to the motor drive unit; the power output ends of the multiple motors of the motor drive unit are connected to the mechanical coupling device 7, and the mechanical coupling device 7 couples and outputs the power of the multiple motors, the auxiliary motor 3 and the engine as wheel driving force to achieve continuously variable speed change of the vehicle; In this embodiment, the power of the engine is divided into two parts, power generation and driving, through the mechanical coupling device 7 and the auxiliary motor 3, so that the system can optimize energy utilization under different working conditions and improve fuel economy. The system is equipped with multiple electric motors, auxiliary motors 3 and engines. The driving force source of the tractor is no longer single, but is dynamically coordinated by multiple power sources. The power output can be intelligently adjusted according to different operating requirements, achieving higher drive control accuracy and improving the flexibility of system power regulation.

[0019] In this embodiment, an auxiliary motor 3 is provided to output the kinetic energy of the engine to the motor drive system, thereby achieving an optimized distribution of the engine output power and improving the utilization rate; at the same time, when the auxiliary motor 3 can be reversed, it can be used as a motor to provide driving power for the gears, so that the driving force source for the wheel drive can include multiple motors, the auxiliary motor 3 and the engine, thereby improving the flexibility of driving force regulation, achieving fine-grained driving force regulation, and being able to achieve stepless speed change in a wider range, and realizing efficient stepless speed change drive and external device driving functions through the precise coordination of the main components.

[0020] Furthermore, in the motor drive unit, a power output end of at least one motor is connected to a power drive shaft (PTO), and the PTO is used to transmit power to external equipment, such as agricultural machinery, to ensure efficient operation of the tractor during work.

[0021] Optionally, one or more motors of the motor drive unit are connected to a power take-off shaft (PTO) of the working component via a clutch CPTO; In some embodiments, when the auxiliary motor 3 is running forward, it generates electricity to convert the kinetic energy output by the engine into electrical energy; when the auxiliary motor 3 is running reversely, it acts as an electric motor to transmit the kinetic energy to the mechanical coupling device 7 for auxiliary driving.

[0022] Specifically, the power shaft of the auxiliary motor 3 is connected to the planet carrier 76 of the mechanical coupling device 7 through the second gear 8; In some embodiments, the motor drive unit may include a plurality of parallel drive branches, each drive branch including a power battery and a motor connected in series; the power battery is connected to the power output end of the auxiliary motor 3 to receive the power of the auxiliary motor 3; the output end of each motor is connected to a clutch, and the clutches connected to each motor are cascaded and connected to an input end of the mechanical coupling device 7 through the first gear 6; The drive branch can be set as needed, preferably, as Figure 1 As shown, in this embodiment, two driving branches are set: the first driving branch includes a first power battery 4 and a first motor 1 connected in series, and a clutch CMotor2 is set at the output end of the first motor 1; the second driving branch includes a second power battery 5 and a second motor 2 connected in series, and a clutch CMotor1 is set at the output end of the second motor 2. The output ends of the clutch CMotor2 and the clutch CMotor1 are meshed and connected to realize cascading, and the output power of the two motors is superimposed and coupled, and is connected to the mechanical coupling device 7 through the first gear 6. The auxiliary motor 3 acts as an auxiliary motor, providing power to the power battery of the motor drive unit in the charging mode; in the joint drive mode, the first motor 1 and the second motor 2 jointly provide power to the wheels to achieve stepless speed change. The first power battery 4 and the second power battery 5 are responsible for providing the required power for the motor, and are charged and discharged according to different working modes to ensure the continuous operation of the system.

[0023] In some embodiments, the mechanical coupling device 7 adopts a planetary gear mechanism, such as Figure 1As shown, the planetary gear mechanism includes a large ring gear 71, a first sun gear 73, a first planetary gear 75, a second sun gear 72, a second planetary gear 74 and a planet carrier 76; the second sun gear 72, the second planetary gear 74 and the planet carrier 76 are connected in sequence; the first sun gear 73, the first planetary gear 75 and the planet carrier 76 are connected in sequence; the first sun gear 73 and the large ring gear 71 are respectively connected to the power output end of the engine through a clutch structure; the second sun gear 72 is connected to the power output end of the motor drive unit; Specifically, in this embodiment, the second sun gear 72 is connected to the output end of the clutch CMotor1 of the motor drive unit through the first gear 6 .

[0024] When in use, if the motor drive unit is used for driving, the clutch CMotor2 at the output end of the first motor 1 is engaged, the clutch CMotor1 at the output end of the second motor 2 is engaged, the clutch CMotor2 and the clutch CMotor1 power output ends are connected, and then the power of the two motors is superimposed and transmitted to the second sun gear 72 through the first gear 6, and then output to the driving wheels through the second planetary gear 74 and the planetary carrier 76; when one of the motors outputs power, the power is directly transmitted to the first gear 6 through the corresponding clutch; If the engine is used for driving, the power output end of the engine transmits power to the first planetary gear 75 through the first sun gear 73, and outputs the power through the planet carrier 76; or / and, transmits power to the first planetary gear 75 through the large ring gear 71, and outputs the power through the planet carrier 76; The planetary gear mechanism of this embodiment distributes the input power to each gear assembly through precise gear matching and the relative movement of the planet carrier 76 and the sun gear, thereby ensuring smooth power transmission. With this structure, the system can achieve stepless speed change and efficient power distribution, meeting the needs of tractors or other machinery in various working environments.

[0025] In a further technical solution, a clutch structure is connected to the power output end of the engine (Engine), and is connected between the engine (Engine) and the mechanical coupling device 7; The clutch structure includes a clutch C1, a clutch C2 and a clutch C3; the clutch C1 and the clutch C2 are connected to the power output shaft of the engine in sequence; the clutch C3 is connected to the power output end of the engine through the third gear 9; the clutch C3 and the clutch C1 are connected to the first sun gear 73 through the fourth gear 10; the clutch C2 is connected to the large ring gear 71 of the planetary gear mechanism through the fifth gear 11; When the clutch C1 is engaged or / and the clutch C3 is engaged, the power of the engine is transmitted via the fourth gear 10 and finally transmitted to the first sun gear 73 of the planetary gear mechanism, achieving a specific power split or speed regulation; When the clutch C2 is engaged, the power of the engine is connected to the large ring gear 71 of the planetary gear mechanism through the fifth gear 11, and enters the transmission system through different gear paths to meet different working conditions. Furthermore, a lock LOCK2 is provided at the power output end of the fourth gear 10, which can lock the gear assembly under certain circumstances to optimize the power transmission efficiency or realize the switching of different driving modes; Furthermore, a lock LOCK1 is provided outside the large gear ring 71 of the planetary gear mechanism, which is used to fix the large gear ring 71 under certain circumstances, thereby changing the transmission mode of the planetary gear mechanism, optimizing the power output or realizing different driving modes; A further technical solution is to interlock the lock LOCK2 and the lock LOCK1 to achieve the output of the engine in different power ranges. When the lock LOCK2 is locked, the lock LOCK1 is disconnected; when the lock LOCK2 is disconnected, the lock LOCK1 is locked; both the lock LOCK1 and the lock LOCK2 are disconnected.

[0026] In this embodiment, the power output of the engine can be adjusted to a corresponding set range through interlocking control, and power outputs of multiple power ranges of different sizes can be achieved through two locks, thereby improving the flexibility of power output regulation.

[0027] During the speed change process, clutch C1, clutch C2 and clutch C3 are adjusted according to different gears to achieve stepless speed change under various working conditions. Locker LOCK1 and locker LOCK2 respectively control the large ring gear 71 and the sun gear in the planetary gear mechanism to ensure that the power can be output normally. Through the precise coordination of the planetary gear mechanism, the motor and the engine can flexibly adjust the power output of the wheels when working together to achieve stepless speed change drive.

[0028] The power output structure connected to the rear end of the planetary carrier 76 provides power for the wheels. The engine output structure includes multiple gear pairs, which are connected to the CVT Out end of the drive shaft of the wheels through the gear pairs. In the figure, DR (Drive Reverse) and DF (Drive Forward) respectively represent the reverse gear (reverse drive) and forward gear (forward drive) of the transmission system.

[0029] The hybrid electric-controlled continuously variable transmission power drive system can realize multiple working modes, as shown in Table 1, including the following working modes: (1) Working mode 1: engine driven and charging mode, the engine works to provide charging power and driving force for the wheels, and the vehicle works through the motor of the motor drive unit to provide driving force; In this mode, the engine power can both drive the wheels and charge the battery, thereby optimizing energy utilization and improving the tractor's operating sustainability and fuel economy.

[0030] According to the different gear positions of the engine, the lock LOCK1 or the lock LOCK2 is controlled to be disconnected, so that the engine controls the wheels alone through the planetary gear mechanism, and drives the auxiliary motor 3 to generate electricity at the same time. When the power stored in the power battery is lower than the threshold, the power is stored in the first power battery 4 and the second power battery 5 to prepare for driving the first motor 1 and the second motor 2; If the tractor has an operation requirement, the clutch CPTO is engaged, and the first power battery 4 supplies power to the first motor 1, which performs work outwardly through the power output shaft (PTO).

[0031] In this mode, only the engine is outputting power. It is suitable for situations where the power battery is insufficient and needs to be charged after the tractor completes the work, or when working in a flat area or driving on flat ground with low power demand.

[0032] In this mode, the engine's power is transmitted bidirectionally through mechanical connection, so that the two working functions of power generation and traction can work together, thereby optimizing energy efficiency and improving power stability during operation. According to the gear, through the selective engagement of LOCK1 or LOCK2, the output of the engine in different power ranges can be adjusted, and the wheels can be precisely controlled under different working conditions. When the soil moisture, viscosity or load changes, the tractor can rely on the engine to directly drive the wheels, while adjusting the power distribution and optimizing fuel consumption. The engine is not only used for traction, but also for power generation, making efficient use of surplus power and reducing fuel waste. Through bidirectional power transmission, the engine is ensured to operate under the best working conditions, improving the economy of the overall system, and being able to charge while working to avoid interruptions due to battery exhaustion. This mode allows the tractor to rely mainly on engine drive under light load or flat terrain, while charging at the same time, so that it can rely on battery assistance in complex terrain to improve operation stability.

[0033] (2) Working mode 2: Collaborative working mode, the engine works, the motor drive unit works, and the output power of the engine and the motor is collaboratively controlled according to the wheel load requirements; the system realizes the joint operation of the engine and multiple motors through reasonable power distribution and control to meet the various operating requirements of the tractor in complex environments; In this mode, the power output of the engine is adjusted according to the load, and the power output of the motor is adjusted to achieve the joint operation of the motor and the engine, and the control realizes the following coordinated working state; 2.1) Clutch CMotor1 and clutch CPTO are engaged, lock LOCK1 and lock LOCK2 are both disconnected, the first motor 1 provides power to the power output shaft (PTO), and the second motor 2 and the engine are coupled through the planetary gear mechanism to jointly provide power to the wheels, so that the tractor can perform stepless speed change; 2.2) Clutch CMotor2, clutch CMotor1 and clutch CPTO are all engaged, lock LOCK1 and lock LOCK2 are both disconnected, the first motor 1 provides power to the power output shaft (PTO), and the first motor 1, the second motor 2 and the engine are power-coupled through the planetary gear mechanism to jointly provide power to the wheels, so that the tractor can perform stepless speed change; In this cooperative working state, the first motor 1 can provide power to the wheels, thereby preventing the first motor 1 from entering an idle state when the PTO is not working.

[0034] 2.3) When the system workload is different, the engine power output can be adjusted according to the clutch gear selection; 2.4) The auxiliary motor 3 is driven according to the battery power level. If charging is required, the auxiliary motor 3 is controlled to rotate forward to charge the power battery. When charging is not required, the auxiliary motor 3 can be reversed to provide assistance to the planetary carrier 76 in the planetary gear mechanism, which is equivalent to indirectly supplying energy to the wheels.

[0035] In this mode, the precise cooperation of the engine and the motor ensures the rational use of energy while providing stable power, making the tractor's operation in complex environments more efficient and stable, and improving the system's adaptability and overall operating efficiency. The engine and the three motors are driven together to provide flexible and sufficient power under different workloads, ensuring the stability of the tractor's operation in complex environments. Through the coordinated work of the engine and the motor, the system can flexibly distribute power to adapt to different working scenarios. The auxiliary motor 3 can be reversed to convert the electrical energy stored in the battery into mechanical energy to drive the planetary carrier 76 to participate in power output; the dual function of the generator ensures that power can be provided efficiently when needed, and can also charge the battery without affecting the operating efficiency. Under low load conditions, the motor can provide additional acceleration force; when starting or when the instantaneous load is large, the motor can provide high torque output; and the engine can provide stable traction to adapt to more continuous power requirements. Through the cooperation of the engine and the motor, accurate power distribution is achieved, which improves the efficiency of energy utilization and the efficiency of operation. The system can be adjusted intelligently to reduce fuel waste, while improving the efficiency of battery use, ensuring that the tractor can continue to operate under complex working conditions.

[0036] (3) Working mode 3: Electric mode, in which the engine stops working completely and the movement of the tractor is completely powered by the electric motor drive unit; In this mode, the engine does not work, the lock LOCK1 and the lock LOCK2 are both in the locked state; the clutch CPTO is disconnected; the second motor 2 and the auxiliary motor 3 are controlled to work, and the clutch CMotor1 is engaged, which can effectively transmit the power of the second motor 2 and the auxiliary motor 3 to the wheels; The power output of the auxiliary motor 3 acts as a booster on the planet carrier 76 of the planetary gear mechanism; the clutch CPTO is disconnected; In this mode, the tractor's power source comes entirely from the electricity in the battery, which is suitable for starting or short-term low-power operation. The engine has poor fuel economy when starting cold, and the electric motor can provide efficient and instantaneous torque output, which is especially suitable for tractor starting and low-speed driving. The tractor's acceleration performance when starting with the engine is also obviously not as good as that of the electric motor. When starting, it can reduce emissions and quickly reach the predetermined speed by relying entirely on the electric motor. Therefore, when the tractor is just started, the PTO is generally not required to operate. This mode does not require the first motor 1 to operate, the clutch CPTO is disconnected, the clutch CMotor2 is also disconnected, and the power of the first power battery 4 is basically supplied to the second motor 2 and the auxiliary motor 3.

[0037] In electric mode, the engine stops working completely and only relies on the electric motor to drive the tractor, which reduces the tractor's emissions and meets environmental protection requirements. It also maintains low noise during operation and is suitable for situations where environmental pollution and noise need to be reduced. By completely eliminating the engine's fuel consumption, zero-emission operation is achieved, which is very suitable for work scenarios with high environmental protection requirements, such as indoor operations or work environments near cities. When the battery is fully charged, the electric motor provides smooth and continuous power output, maximizing the use of battery power and reducing energy waste; the electric mode is suitable for tractors in starting, low-speed driving and low-load operations, especially for cold starts and short-term low-power operations, and can provide faster response and efficient power output.

[0038] Table 1 Component operation status in each working mode;

[0039] This embodiment provides a multi-mode working mode of the hybrid power system, including engine drive and power generation, engine and motor joint drive, and motor drive alone; so that the tractor can be flexibly adjusted according to different working environments and needs. Whether it is heavy-load farming or low-speed, fine work, the system can provide the most appropriate power support, enhance the adaptability of the tractor, and improve work efficiency and operational convenience. At the same time, it can achieve efficient energy utilization in various working modes and improve the overall efficiency of the system.

[0040] Example 2 Based on Example 1, this embodiment provides a driving control method for a hybrid electric-controlled continuously variable power drive system based on Example 1, such as Figure 2 As shown, the following steps are included; Step 1: Get the vehicle operation instruction, and when starting the vehicle, enter the electric mode; Step 2: When the vehicle is in working state, it receives the PTO power output command and outputs the rotary tillage power through the motor; if the wheel power output needs to be less than the set threshold, it enters the engine drive and charging mode, and the engine provides the driving force for the wheel; otherwise, it enters the collaborative working mode, and the engine and the motor are collaboratively controlled to provide power to the wheel; Step 3: When the vehicle is in the engine-operating state, in response to a battery charging request, the vehicle switches to the engine-operating mode to charge the battery; The traditional power distribution mechanism cannot accurately cope with complex operating scenarios, resulting in unbalanced power. Especially in the starting, acceleration, steering and other links, the coordinated work of the motor and the engine may lag or mismatch, affecting the tractor's operating stability and power response speed. To address this problem, the drive control method proposed in this embodiment controls the coordinated work between the motor and the engine through precise working mode switching, and can flexibly adjust the power output under different working conditions to ensure power balance and efficient use. By real-time monitoring of vehicle load and battery power, this method can ensure that the system responds quickly and provides stable power output under complex working conditions, avoiding the lag and instability that may occur in traditional systems.

[0041] In step 1, the electric mode is the working mode 3, in which the engine stops working, the lock LOCK1 and the lock LOCK2 are both in the locked state; the clutch CPTO is disconnected; the second motor 2 and the auxiliary motor 3 are controlled to work, the clutch CMotor1 is engaged, and the clutch CMotor2 is disconnected, and the power coupling of the second motor 2 and the auxiliary motor 3 is transmitted to the wheels; In step 2, the engine driving and charging mode is working mode 1. According to the different engine gears, the lock LOCK1 or the lock LOCK2 is controlled to be disconnected, so that the engine drives the wheels alone through the planetary gear mechanism, and drives the auxiliary motor 3 to generate electricity. When the power stored in the power battery is lower than the threshold, the power is stored in the first power battery 4 and the second power battery 5; If there is a work requirement and a PTO power output command is received, the clutch CPTO is engaged, and the first power battery 4 supplies power to the first motor 1 to perform work outwardly through the power output shaft (PTO).

[0042] In step 2, the wheel power output needs to be less than the set threshold, that is, the vehicle is in a relatively flat operating area and can be operated by the engine alone; In step 2, when entering the collaborative working mode, the engine and the electric motor are collaboratively controlled to provide power to the wheels according to different wheel loads. Specifically: Step 21, setting a first wheel load threshold range and a second wheel load threshold range that increase in sequence; Optionally, the first wheel load threshold range may be set to 0~A, and the second wheel load threshold range may be set to be greater than A, where A is a set load threshold; Step 22, obtaining wheel loads, when within the first wheel load threshold range, controlling the clutch CMotor1 and the clutch CPTO to engage, the lock LOCK1 and the lock LOCK2 to disengage, the first motor 1 to provide power to the power output shaft (PTO), and the second motor 2 and the engine to provide power to the wheels together after power coupling through the planetary gear mechanism; Step 23, when the wheel load is within the second wheel load threshold range, the clutch CMotor2, the clutch CMotor1 and the clutch CPTO are all engaged, the lock LOCK1 and the lock LOCK2 are both disconnected, the first motor 1 provides power to the power output shaft (PTO), and the first motor 1, the second motor 2 and the engine are power-coupled through the planetary gear mechanism and jointly provide power to the wheels; Furthermore, in the collaborative working mode, the working state of the auxiliary motor 3 is driven according to the battery power. If charging is required, the auxiliary motor 3 is controlled to rotate forward to charge the power battery. When charging is not required, the auxiliary motor 3 can be reversed to provide assistance to the planetary carrier in the planetary gear mechanism, which is equivalent to indirectly supplying energy to the wheels.

[0043] Example 3 Based on Example 1, this example provides a tractor, which uses a hybrid electric-controlled continuously variable power drive system described in Example 1 to provide power for the operation and wheels of the tractor.

[0044] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

[0045] Although the above describes the specific implementation methods of the present disclosure in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present disclosure. Technical personnel in the relevant field should understand that on the basis of the technical solution of the present disclosure, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present disclosure.

Claims

1. A hybrid electric controlled continuously variable speed power drive system, characterized in that: include: A generator, a mechanical coupling device, an electric motor drive unit and an auxiliary motor capable of forward and reverse rotation connected in sequence; The engine is connected to the auxiliary motor via a mechanical coupling device to provide electrical energy to the electric motor drive unit; The power output ends of the multiple motors of the motor drive unit are connected to the mechanical coupling device, and the mechanical coupling device couples and outputs the power of the multiple motors, the auxiliary motor and the engine to drive the wheels.

2. A hybrid electric controlled continuously variable speed power drive system as claimed in claim 1, characterized in that: In the motor drive unit, a power output end of at least one motor is connected to a power drive shaft PTO.

3. A hybrid electric-controlled continuously variable power drive system as claimed in claim 1, characterized in that: The auxiliary motor generates electricity in the forward direction, which is used to convert the kinetic energy output by the engine into electrical energy; when the auxiliary motor is reversed, it acts as an electric motor and transmits the kinetic energy to the mechanical coupling device for auxiliary driving.

4. A hybrid electric-controlled continuously variable power drive system as claimed in claim 1, characterized in that: The motor drive unit includes a plurality of parallel drive branches; Each driving branch includes a power battery and an electric motor connected in series; The power battery is connected to the power output terminal of the auxiliary motor to receive the power of the auxiliary motor; The output end of each motor is connected with a clutch, and the clutches connected to each motor are cascaded and connected to an input end of the mechanical coupling device through a first gear.

5. A hybrid electric-controlled continuously variable power drive system as claimed in claim 1, characterized in that: The mechanical coupling device adopts a planetary gear mechanism, including a large ring gear, a first sun gear, a first planet gear, a second sun gear, a second planet gear and a planet carrier; The second sun gear, the second planetary gear and the planet carrier are connected in sequence; The first sun gear, the first planet gear and the planet carrier are connected in sequence; The first sun gear and the large ring gear are respectively connected to the power output end of the engine through a clutch structure; The second sun gear is connected to the power output end of the motor drive unit.

6. A hybrid electric-controlled continuously variable power drive system as claimed in claim 5, characterized in that: The power output end of the engine is connected with a clutch structure, which includes a clutch C1, a clutch C2 and a clutch C3; Clutch C1 and clutch C2 are connected to the power output shaft of the engine in sequence; Clutch C3 is connected to the power output of the engine through the third gear; The clutch C3 and the clutch C1 are connected to the first sun gear through the fourth gear; a lock LOCK2 is provided at the power output end of the fourth gear 10; Clutch C2 is connected to the large ring gear of the planetary gear mechanism through the fifth gear; A lock LOCK1 is arranged outside the large ring gear of the planetary gear mechanism.

7. A hybrid electric-controlled continuously variable power drive system as claimed in claim 6, characterized in that: Interlocking control is performed on lock LOCK2 and lock LOCK1 to achieve output of different power ranges of the engine, including: When the lock LOCK2 is locked, the lock LOCK1 is disconnected; When the lock LOCK2 is disconnected, the lock LOCK1 is locked; Both lock LOCK1 and lock LOCK2 are disconnected.

8. A driving control method for a hybrid electric-controlled continuously variable power drive system according to any one of claims 1 to 7, characterized in that: The steps include: Obtain vehicle operation instructions and enter electric mode when starting the vehicle; When the vehicle is in working state, it receives the PTO power output command and outputs the rotary tillage power through the electric motor; If the wheel power output needs to be less than the set threshold, the engine drive and charging mode is entered, and the engine provides driving force for the wheels; Otherwise, it enters the collaborative working mode, providing power to the wheels through the coordinated control of the engine and the electric motor; When the vehicle's engine is running, in response to a battery charging request, it switches to an engine running mode to charge the battery.

9. The driving control method according to claim 8, characterized in that: In the engine driving and charging mode, the engine works to provide charging power and driving force for the wheels, and the vehicle works by providing driving force through the motor of the motor drive unit; In electric mode, the engine stops working and the electric motor of the motor drive unit provides power; When entering the collaborative working mode, the engine and the electric motor are collaboratively controlled to provide power to the wheels according to different wheel loads. Specifically: Setting a first wheel load threshold range and a second wheel load threshold range with increasing thresholds in sequence; The wheel load is obtained. When the first wheel load threshold is within the range, the clutch CMotor1 and the clutch CPTO are controlled to be engaged, the lock LOCK1 and the lock LOCK2 are both disconnected, the first motor provides power to the power output shaft, and the second motor and the engine are power coupled to provide wheel power; When the wheel load is within the second wheel load threshold range, clutch CMotor2, clutch CMotor1 and clutch CPTO are all engaged, lock LOCK1 and lock LOCK2 are both disconnected, the first motor provides power to the power output shaft, and the first motor, the second motor and the engine are power coupled and jointly provide power to the wheels.

10. A tractor, characterized in that: A hybrid electric-controlled continuously variable power drive system as described in any one of claims 1 to 7 is used to provide power for the operation and wheels of the tractor.

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