Planetary gear type hybrid power system and control method thereof

Abstract

The invention discloses a planetary gear type hybrid power system and a control method thereof, and relates to the technical field of new energy automobile hybrid power transmission systems, the planetary gear type hybrid power system comprises an engine, two groups of motors, two groups of planet rows, a clutch, a brake and a structural element arranged between the planet rows and used for transmitting power; the engine and the two groups of motors are respectively combined and connected with the two groups of planet rows through different structural elements to form a planetary gear type hybrid power transmission system; six driving modes of pure electric driving, engine direct driving, power dividing, parallel driving, braking energy recovery and parking charging can be realized by controlling the working states of the motors, the clutches and the brakes; compared with fixed shaft type gear arrangement, the planetary gear combination reduces use of a gear shifting fork, has the advantages of being compact in structure, high in integration degree, clear in gear shifting logic and larger in torque capacity, and improves the power transmission efficiency of an automobile hybrid power system.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicle drive systems, and particularly relates to a planetary gear type hybrid power system and a control method thereof. Background Art

[0002] As an important direction for the green transformation of the automotive industry, the power system of new energy vehicles has become one of the core technologies of automobiles. Among them, the hybrid power system has occupied an increasingly important position in the automotive market due to its advantages in fuel economy, exhaust emissions, and power performance, and is one of the currently very valuable key components of new energy vehicles. The current usage scenarios of new energy vehicles are becoming increasingly complex. Vehicles need to have high torque output during startup and climbing, and can also achieve high-speed power output. However, most of the current mainstream dual-motor hybrid power systems in China are single-gear, which cannot meet the requirements of improving the economy and power performance of the whole vehicle. A few models are equipped with multi-gear hybrid power systems, but the current multi-gear hybrid power systems mostly adopt a fixed-axis gear transmission layout and use a shift fork for shifting, which often results in power interruption or shift shock, affecting driving comfort.

[0003] Therefore, it is very necessary to research and develop a new hybrid power system with a more compact structure, higher integration level, better shift comfort, and superior power transmission performance to ensure that the vehicle has better adaptability to driving conditions, thereby improving the power performance and economy of the vehicle. Summary of the Invention

[0004] In view of the problems that the vehicle needs to adapt to different working conditions for different usage scenarios, and most of the current mainstream hybrid power systems are single-gear, and using a shift fork for shifting will cause power interruption or shift shock, affecting driving comfort, etc., the first aspect of the present invention proposes a planetary gear type hybrid power system, including: an engine 100, a first motor M1, a second motor M2, a first planetary gear set, a second planetary gear set, a clutch, a brake, and a structural element for transmitting power disposed between the planetary gear sets; The first planetary gear set is planetary gear set P1, including a first sun gear S1, a first planet carrier H1, and a first ring gear R1; the second planetary gear set is composed of planetary gear set P2 and planetary gear set P3, and the second planetary gear set includes a second sun gear S2, a third sun gear S3, a second planet carrier H2, and a second ring gear R2; The clutch is clutch C1, the brake includes a first brake B1 and a second brake B2, the first motor M1 includes a stator 10 and a rotor 11, and the second motor M2 includes a stator 20 and a rotor 21; The structural element includes a housing 9, a first structural element 1, a second structural element 2, a third structural element 3, a fourth structural element 4, a fifth structural element 5, and a sixth structural element 6; The first structural element 1 connects the first ring gear R1 and the second planet carrier H2, and is also connected to the clutch C1; the other end of the clutch C1 is connected to the power output shaft of the engine 100. Of course, a damping disc can also be provided between the clutch C1 and the engine 100; one end of the second structural element 2 is connected to the first sun gear S1, and the other end is connected to the rotor 11 of the first motor M1; one end of the third structural element 3 is connected to the third sun gear S3, and the other end is connected to the rotor 21 of the second motor M2; one end of the fourth structural element 4 is connected to the second sun gear S2, and the other end is connected to the first brake B1; one end of the fifth structural element 5 is connected to the second planet carrier H2, and the other end is connected to the second brake B2; one end of the sixth structural element 6 is connected to the first planet carrier H1, and the other end is connected to the second ring gear R2.

[0005] Further, each planetary gear set is completely symmetrical with respect to the center of rotation. The power output shaft of the engine 100, the first motor M1, and the second motor M2 are installed on the same axis. The stator 10 of the first motor M1 and the stator 20 of the second motor M2 are both fixedly connected to the housing 9.

[0006] Further, the second planetary gear set further includes planetary gears X2 and X3. The planetary gears X2 and X3 are installed on the same planet carrier. The planetary gear X2 meshes with the planetary gear X3, the second sun gear S2, and the second ring gear R2 respectively. The planetary gear X3 meshes with the planetary gear X2 and the third sun gear S3 respectively; The planetary gear sets P2 and P3 share the same planet carrier, that is, the second planet carrier H2 serves as the planet carrier of the compound planetary gear set; the planetary gear sets P2 and P3 share the same ring gear, that is, the second ring gear R2 serves as the ring gear of the compound planetary gear set; One end of the first brake B1 is connected to the housing 9, and the other end is connected to the fourth structural element 4; one end of the second brake B2 is connected to the housing 9, and the other end is connected to the fifth structural element 5.

[0007] Further, the second structural element 2 is designed as a hollow shaft for the first structural element 1 to pass through; it can be understood that this structural design further improves the overall compactness of the system through reasonable layout.

[0008] Further, the planetary gears X1 are usually circumferentially and uniformly arranged in a plurality along the circumference of the first sun gear S1; the planetary gears X2 and X3 are respectively circumferentially and uniformly arranged in a plurality along the circumferences of the second sun gear S2 and the third sun gear S3.

[0009] Further, both the first motor M1 and the second motor M2 are connected to the controller; the hybrid power system further includes a battery, a motor driver, etc. The battery is connected to the motor driver, the first motor M1, and the second motor M2. This part is the same as the existing dual-motor hybrid power system.

[0010] The second aspect of the present application discloses a control method for a planetary gear type hybrid power system. The control method is used to control the above hybrid power system; wherein the control method can switch the hybrid power system to a pure electric mode, an engine direct drive mode, a power split mode, a parallel drive mode, a braking energy recovery mode, and a parking charging mode by controlling the working states of the engine 100, the clutch C1, the brake B1, the brake B2, the first motor M1, and the second motor M2.

[0011] Further, to control the hybrid power system to switch to the pure electric drive mode, the method includes: the engine 100 stops working, Combined with the second brake B2, the first motor M1 drives and the second motor M2 does not work. The hybrid power system has a pure electric first gear; Combined with the second brake B2, the first motor M1 does not work and the second motor M2 drives. The hybrid power system has a pure electric second gear; Combined with the first brake B1, the first motor M1 drives and the second motor M2 does not work. The hybrid power system has a pure electric third gear; Combined with the first brake B1, the first motor M1 does not work and the second motor M2 drives. The hybrid power system has a pure electric fourth gear.

[0012] Further, to control the hybrid power system to switch to the engine direct drive mode, the method includes: the engine 100 starts to work, Combined with the clutch C1, by controlling the speed of the second motor M2 to zero, the rotation speed of the third sun gear S3 is thus zero. The hybrid power system has an engine direct drive first gear; Combined with the clutch C1, by controlling the speed of the first motor M1 to zero, the rotation speed of the first sun gear S1 is thus zero. The hybrid power system has an engine direct drive second gear Combined with the clutch C1 and the first brake B1, the power output by the engine 100 is transmitted to the sixth structural element 6 through the second planetary gear set. The hybrid power system has an engine direct drive third gear.

[0013] Further, controlling the hybrid power system to switch to the power split mode, the method includes: The engine 100 starts to operate, and the clutch C1 is engaged. The power output by the engine 100 is transmitted to the first ring gear R1 and the second planet carrier H2. The first motor M1 can be controlled to generate electricity, and the second motor M2 drives; or the second motor M2 is controlled to generate electricity, and the first motor M1 drives.

[0014] Further, when the hybrid power system switches to the parallel drive mode, the method includes: The engine 100 starts to operate The clutch C1 is engaged, the first motor M1 drives, and the second motor M2 does not operate. The hybrid power system has a first gear for parallel drive; The clutch C1 is engaged, the first motor M1 does not operate, and the second motor M2 drives. The hybrid power system has a second gear for parallel drive.

[0015] Further, controlling the hybrid power system to switch to the braking energy recovery mode, the method includes: The engine 100 stops operating, and the second brake B2 is engaged. The rotational torque is transmitted to the first planet carrier H1 and the second ring gear R2 through the sixth structural element 6. The first sun gear S1 and the third sun gear S3 rotate, and both the first motor M1 and the second motor M2 rotate to generate electricity.

[0016] Further, controlling the hybrid power system to switch to the parking charging mode, the method includes: It can be understood that the rotational speed of the sixth structural element 6 is zero during parking. The engine 100 starts to operate, and the clutch C1 is engaged. The power output by the engine 100 is transmitted to the first ring gear R1 and the second planet carrier H2. The first sun gear S1 and the third sun gear S3 rotate, and both the first motor M1 and the second motor M2 rotate to generate electricity.

[0017] In the above technical solution, the planetary gear type hybrid power system and its control method provided by the present invention have the following beneficial effects: 1. The planetary gear type hybrid power system and its control method proposed by the present invention. This planetary gear type hybrid power system uses a planetary gear set for transmission and realizes the change of the working state by changing the working state of the planetary row when switching the working state, reducing the use of brakes and clutches. The shift operation can adapt to different vehicle usage scenarios, and the power transmission performance is excellent; compared with a shift fork, it has a more compact structure, a higher degree of integration, better shift comfort, a larger torque capacity, a clear shift logic, simple control, can effectively avoid problems such as shift gear clash, and does not require a dedicated shift operating mechanism for operating the shift fork.

[0018] 2. This planetary gear type hybrid power system adopts a dual-motor structure, which can utilize the motors to achieve driving or power generation. The power utilization rate of the motors is high, the acceleration performance is good, and the layout of the transmission device is optimized. It can also, according to requirements, achieve separate driving or simultaneous driving of the engine and the motors to realize direct engine drive, pure electric drive, power split or parallel drive operation, improve the flexibility of power source selection, increase the output power in the hybrid drive state, and meet the power demand.

[0019] 3. This planetary gear type hybrid power system controls the planetary gear set or the motors to shift gears when the engine is in direct drive, so that when at a relatively high vehicle speed, the engine can maintain an operating condition with better fuel economy and reduce the operating fuel consumption of the engine. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. By referring to the drawings, the features and advantages of the present invention will be more clearly understood. The drawings are schematic and should not be construed as imposing any limitation on the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Wherein: Figure 1 is a schematic structural diagram of the planetary gear type hybrid power system of the present invention.

[0022] Figure 2 is a schematic diagram of the relationship between the planetary trains of the planetary gear type hybrid power system of the present invention.

[0023] Wherein: 1 - 6 are six structural elements, C1 is a clutch, B1 - B2 are two brakes, P1 is a single-stage planetary train, and P2, P3 are two single-stage planetary trains that form the second planetary train.

[0024] R1 is the ring gear of P1, H1 is the planet carrier of P1, S1 is the sun gear of P1, R2 is the common ring gear of P2 and P3, H2 is the common planet carrier of P2 and P3, S2 is the sun gear of P2, S3 is the sun gear of P3, X2 is the planet gear of P2, X3 is the planet gear of P3, 10 is the stator of the first motor M1, 11 is the rotor of the first motor M1, 20 is the stator of the second motor M2, and 21 is the rotor of the second motor M2. DETAILED DESCRIPTION OF THE EMBODIMENTS The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention and the accompanying drawings. The illustrations provided in the following embodiments only schematically illustrate the basic concept of the present invention. Without conflict, the following embodiments and the features in the embodiments can be combined with each other. To better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product. In the present invention, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; the term "plurality" means two or more; words such as "set", "connected" should be understood in a broad sense unless otherwise clearly defined. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted, which cannot be understood as a limitation of the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0026] The housing 9 described herein is always stationary. The first motor M1 includes a stator 10 and a rotor 11, and the second motor M2 includes a stator 20 and a rotor 21. In the engine direct drive mode, the locked state of the first motor M1 and the second motor M2 means that the rotational speed of the motor rotor is zero. And controlling the rotational speed of the motor to zero belongs to the well-known technology in the field of electrical control engineering and is not the focus of the present invention, so it will not be introduced hereinafter. Each planetary gear set in this hybrid power system is completely symmetric with respect to the rotation center, Figure 1 and Figure 2 the lower half of the rotation center is omitted and will not be described hereinafter.

[0027] Embodiment: Please refer to Table 1, Figure 1 and Figure 2 , a planetary gear type hybrid power system according to an embodiment of the first aspect of the present invention, includes: an engine 100, a first motor M1, a second motor M2, a first planetary gear set, a second planetary gear set, a clutch, a brake, and a structural element disposed between the planetary gear sets for transmitting power; the first planetary gear set is the planetary gear set P1 including a first sun gear S1, a first planetary carrier H1, and a first ring gear R1; the second planetary gear set is composed of the planetary gear set P2 and the planetary gear set P3, and the second planetary gear set includes a second sun gear S2, a third sun gear S3, a second planetary carrier H2, and a second ring gear R2; The clutch is the clutch C1, the brake includes a first brake B1 and a second brake B2, the first motor M1 includes a stator 10 and a rotor 11, and the second motor M2 includes a stator 20 and a rotor 21; the structural element includes a housing 9, a first structural element 1, a second structural element 2, a third structural element 3, a fourth structural element 4, a fifth structural element 5, and a sixth structural element 6; The first structural element 1 connects the first ring gear R1 and the second planet carrier H2, and is also connected to the clutch C1. It can be understood that the first ring gear R1 and the second planet carrier H2 are fixedly connected. The other end of the clutch C1 is connected to the power output shaft of the engine 100. One end of the second structural element 2 is connected to the first sun gear S1, and the other end is connected to the rotor 11 of the first motor M1. It can be understood that the rotor 11 of the first motor M1 is fixedly connected to the first sun gear S1. One end of the third structural element 3 is connected to the third sun gear S3, and the other end is connected to the rotor 21 of the second motor M2. It can be understood that the rotor 21 of the second motor M2 is fixedly connected to the third sun gear S3. One end of the fourth structural element 4 is connected to the second sun gear S2, and the other end is connected to the first brake B1. One end of the fifth structural element 5 is connected to the second planet carrier H2, and the other end is connected to the second brake B2. One end of the sixth structural element 6 is connected to the first planet carrier H1, and the other end is connected to the second ring gear R2. It can be understood that the first planet carrier H1 and the second ring gear R2 are fixedly connected.

[0028] The planetary gear hybrid system of the present invention can achieve multiple power modes, mainly including pure electric mode, engine direct drive mode, power split mode, parallel drive mode, braking energy recovery mode and parking charging mode. The power modes are as follows: Please refer to Table 1, Figure 1 and Figure 2 . It can be understood that the engine 100 does not work in each gear of pure electric drive, and the clutch C1 is disengaged to prevent the engine 100 from being dragged backwards.

[0029] Pure electric first gear: Engage the second brake B2 and drive with the first motor M1

[0030] Engage the second brake B2. The second planet carrier H2 is fixedly connected to the housing 9. The rotational speeds of the second planet carrier H2, the first structural element 1, and the first ring gear R1 are zero. Driven by the first motor M1, the rotational speed of the first sun gear S1 is the same as that of the first motor M1. The first motor M1 transmits power to the outside through the second structural element 2, the first sun gear S1, the first planet carrier H1, and the sixth structural element 6 in sequence.

[0031] Pure electric second gear: Engage the second brake B2 and drive with the second motor M2

[0032] Engage the second brake B2. The second planet carrier H2 is fixedly connected to the housing 9, and the rotational speed of the second planet carrier H2 is zero. Driven by the second motor M2, the rotational speed of the third sun gear S3 is the same as that of the second motor M2. The second motor M2 transmits power to the outside through the third structural element 3, the third sun gear S3, the planetary gear X3, the planetary gear X2, the second ring gear R2, and the sixth structural element 6 in sequence.

[0033] Pure electric three-speed: Combine the first brake B1 and the first motor M1 to drive

[0034] Combine the first brake B1. The second sun gear S2 is fixedly connected to the housing 9, and the rotational speed of the second sun gear S2 is zero. Driven by the first motor M1, the first sun gear S1 has the same rotational speed as the first motor M1. The first motor M1 transmits power in sequence to the second structural element 2, the first sun gear S1, the planetary gear X1, the first ring gear R1, the first structural element 1, the second planetary carrier H2, the second ring gear R2, and the sixth structural element 6 to output power externally.

[0035] Pure electric four-speed: Combine the first brake B1 and the second motor M2 to drive Combine the brake B1. The second sun gear S2 is fixedly connected to the housing 9, and the rotational speed of the second sun gear S2 is zero. Driven by the second motor M2, the second motor M2 has the same rotational speed as the third sun gear S3. The second motor M2 transmits power in sequence to the third structural element 3, the third sun gear S3, the planetary gear X3, the planetary gear X2. The third sun gear S3, the planetary gear X3, and the planetary gear X2 transmit power to the second ring gear R2 through the shared planetary carrier H2, and the sixth structural element 6 outputs power externally.

[0036] Engine direct drive first gear: Combine the clutch C1 and control the rotational speed of the second motor M2 to zero Combine the clutch C1. The second planetary carrier H2 is in power connection with the engine 100 and has the same rotational speed. Control the rotational speed of the second motor M2 to zero. The third sun gear S3 has the same rotational speed as the second motor M2, both being zero. The engine 100 transmits power to the clutch C1, the first structural element 1, the second planetary carrier H2, the second ring gear R2, and the sixth structural element 6 to output power externally.

[0037] Engine direct drive second gear: Combine the clutch C1 and control the rotational speed of the first motor M1 to zero Combine the clutch C1. The first ring gear R1 is in power connection with the engine 100 and has the same rotational speed. Control the rotational speed of the first motor M1 to zero. The first sun gear S1 has the same rotational speed as the first motor M1, both being zero. The engine 100 transmits power to the clutch C1, the first structural element 1, the first ring gear R1, the first planetary carrier H1, and the sixth structural element 6 to output power externally.

[0038] Engine direct drive third gear: Combine the clutch C1 and the first brake B1 Combine the first brake B1. The second sun gear S2 is fixedly connected to the housing 9, and the rotational speed of the second sun gear S2 is zero. Combine the clutch C1. The first structural element 1 is in power connection with the engine 100 and has the same rotational speed. The engine 100 transmits power to the clutch C1, the first structural element 1, the second planetary carrier H2, the planetary gear X2, the second ring gear R2, and the sixth structural element 6 to output power externally.

[0039] Power split mode: engage clutch C1 Engage the first ring gear R1 of clutch C1 and the second planet carrier H2 to be in power connection with the engine 100 and rotate at the same speed. The engine 100 transmits power to the clutch C1, the first structural element 1, the first ring gear R1 and the second planet carrier H2; the engine 100 can drive the first motor M1 to rotate. The first motor M1 acts as a generating motor to generate electricity, and the second motor M2 acts as a driving motor; or the engine 100 drives the second motor M2 to rotate. The second motor M2 acts as a generating motor to generate electricity, and the first motor M1 acts as a driving motor. In this mode, according to the vehicle output power demand, through the coordinated operation of the engine 100, the first motor M1, the second motor M2 and the first planetary gear set or the second planetary gear set, ensure that the engine is always in the high-efficiency working range, so as to ensure fuel economy and improve the overall power performance and economy of the vehicle; the engine can have better fuel economy, which is conducive to reducing the use of the battery and improving the battery life, thereby improving the overall economy of the vehicle.

[0040] Parallel drive mode first gear: engage clutch C1, the first motor M1 drives Engage the first ring gear R1 of clutch C1 to be in power connection with the engine 100 and rotate at the same speed. The engine 100 transmits power to the clutch C1, the first structural element 1, the first ring gear R1; at the same time, the first motor M1 drives and transmits power to the second structural element 2 and the first sun gear S1; the two power flows converge on the first planet carrier H1 and then are transmitted to the sixth structural element 6 to output power externally.

[0041] Parallel drive mode second gear: engage clutch C1, the second motor M2 drives Engage the second planet carrier H2 of clutch C1 to be in power connection with the engine 100 and rotate at the same speed. The engine 100 transmits power to the clutch C1, the first structural element 1, the second planet carrier H2; at the same time, the second motor M2 drives and transmits power to the third structural element 3 and the third sun gear S3. The two power flows converge on the second planet carrier H2 and then are transmitted to the second ring gear R2 and the sixth structural element 6 to output power externally.

[0042] Regenerative braking mode: When the vehicle brakes in each of the above modes, the engine 100 does not operate, and the clutch C1 is disengaged to prevent the engine 100 from being dragged in reverse. The second brake B2 is engaged, and the rotational speeds of the second planetary carrier H2, the first structural element 1, and the first ring gear R1 are zero. The first motor M1 and the second motor M2 rotate under reverse torque to generate electricity, and the hybrid system enters the braking energy recovery mode. At this time, the braking energy recovery route is divided into two paths: one path is that the sixth structural element 6, the first planetary carrier H1, the planetary gear X1, the first sun gear S1, the second structural element 2, and the first motor M1 rotate to generate electricity; the other path is that the sixth structural element 6, the second ring gear R2, the planetary gear X2, the planetary gear X3, the third structural element 3, and the second motor M2 rotate to generate electricity. This mode is applied to the braking energy recovery of the vehicle.

[0043] Park charging mode: The engine 100 starts to operate, and the clutch C1 is engaged. It can be understood that when entering the park charging mode, the parking mechanism locks the wheels, and thus the rotational speed of the sixth structural element 6 is zero. When the clutch C1 is engaged, the first ring gear R1 and the second planetary carrier H2 are in power connection with the engine 100 and have the same rotational speed. The engine 100 transmits power to the clutch C1 and the first structural element 1 in sequence. The power is divided into two paths: one path is transmitted to the first ring gear R1, the planetary gear X1, the first sun gear S1, and the second structural element 2, and the first motor M1 acts as a generator to generate electricity; the other path is transmitted to the second planetary carrier H2, the planetary gear X2, the planetary gear X3, the third sun gear S3, and the third structural element 3, and the second motor M2 acts as a generator to generate electricity.

[0044] Reverse gear: The reverse gear has the following two implementation forms 1. Engage the brake B2, and the first motor M1 drives in reverse. The power is transmitted in sequence to the second structural element 2, the first sun gear S1, the first planetary carrier H1, and the sixth structural element 6 to output power in the reverse direction to the outside. 2. Engage the brake B2, and the second motor M2 drives in reverse. The power is transmitted in sequence to the third structural element 3, the third sun gear S3, the planetary gear X3, the planetary gear X2, the second ring gear R2, and the sixth structural element 6 to output power in the reverse direction to the outside.

[0045] Of course, the adaptation relationship between the gear position and the road conditions is not limited to the above situations. Different gear position allocation modes can be arranged according to fuel consumption and power for different road conditions. The adaptation relationship between the gear position and the road conditions is not restricted here.

[0046] Table 1 is the gear position control logic diagram of this planetary gear type hybrid system. Table 1:

[0047] Note: In the table, "√" indicates that the clutch or brake is engaged, and the absence of "√" indicates non-engagement.

[0048] The embodiments described above are some of the embodiments of the present invention, rather than all of them; all other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

Claims

1. A planetary gear hybrid system, characterized in that: It comprises an engine (100), a first motor M1, a second motor M2, a first planetary gear, a second planetary gear, a clutch, a brake, and a structural element arranged between the planetary gears for transmitting power; The first planetary gear is a planetary gear P1, comprising a first sun gear S1, a first planet carrier H1, and a first ring gear R1; The second planetary gear is composed of a planetary gear P2 and a planetary gear P3, and the second planetary gear includes a second sun gear S2, a third sun gear S3, a second planet carrier H2, and a second ring gear R2; The clutch is a clutch C1, the brake comprises a first brake B1 and a second brake B2, the first motor M1 comprises a stator (10) and a rotor (11), and the second motor M2 comprises a stator (20) and a rotor (21); The structural elements include a housing (9), a first structural element (1), a second structural element (2), a third structural element (3), a fourth structural element (4), a fifth structural element (5), and a sixth structural element (6); The first structural element (1) is connected to the first ring gear R1 and the second planetary carrier H2, and is also connected to the clutch C1; the other end of the clutch C1 is connected to the power output shaft of the engine (100); one end of the second structural element (2) is connected to the first sun gear S1, and the other end is connected to the rotor (11) of the first motor M1; one end of the third structural element (3) is connected to the third sun gear S3, and the other end is connected to the rotor (21) of the second motor M2; one end of the fourth structural element (4) is connected to the second sun gear S2, and the other end is connected to the first brake B1; one end of the fifth structural element (5) is connected to the second planetary carrier H2, and the other end is connected to the second brake B2; one end of the sixth structural element (6) is connected to the first planetary carrier H1, and the other end is connected to the second ring gear R2.

2. The planetary gear hybrid system according to claim 1, characterized in that: The planetary gears are completely symmetrical with respect to the center of rotation; the power output shaft of the engine (100), the first motor M1, and the second motor M2 are mounted on the same axis; and the stator (10) of the first motor M1 and the stator (20) of the second motor M2 are both fixedly connected to the housing (9).

3. The planetary gear hybrid power system according to claim 2, characterized in that: The second planetary gear also includes a planetary gear X2 and a planetary gear X3, the planetary gear X2 and the planetary gear X3 are mounted on the same planet carrier, the planetary gear X2 is meshed with the planetary gear X3, the second sun gear S2, and the second ring gear R2, respectively, and the planetary gear X3 is meshed with the planetary gear X2 and the third sun gear S3, respectively; The planetary row P2 and the planetary row P3 share the same planet carrier, that is, the second planet carrier H2 serves as the planet carrier of the compound planetary row; the planetary row P2 and the planetary row P3 share the same ring gear, that is, the second ring gear R2 serves as the ring gear of the compound planetary row; One end of the first brake B1 is connected to the housing (9), and the other end is connected to the fourth structural element (4); one end of the second brake B2 is connected to the housing (9), and the other end is connected to the fifth structural element (5).

4. A control method for a planetary gear hybrid system, characterized in that: The control method controls the working states of the engine (100), the clutch, the brake, the first motor M1 and the second motor M2 to control the hybrid power system as described in any one of claims 1 to 3 to switch to a pure electric mode, an engine direct drive mode, a power split mode, a parallel drive mode, a brake energy recovery mode, or a parking charging mode.

5. The control method of the planetary gear hybrid system according to claim 4, characterized in that: Controlling the hybrid power system to switch to a pure electric driving mode, the method comprising: stopping the engine (100); In combination with the second brake B2, the first motor M1 is driven, the second motor M2 is not operated, and the hybrid system has a pure electric first gear; In combination with the second brake B2, the first motor M1 does not work, the second motor M2 is driven, and the hybrid system has a pure electric second gear; In combination with the first brake B1, the first motor M1 is driven, the second motor M2 is not operated, and the hybrid system has a pure electric third gear; In combination with the first brake B1 , the first motor M1 is not working, the second motor M2 is driving, and the hybrid system has a pure electric fourth gear.

6. The control method of the planetary gear hybrid power system according to claim 4, characterized in that: Controlling the hybrid power system to switch to an engine direct drive mode, the method comprising: starting the engine (100); The clutch C1 is combined to control the speed of the second motor M2 to zero, thereby making the speed of the third sun gear S3 zero; the hybrid system has an engine direct drive first gear; The clutch C1 is combined to control the speed of the first motor M1 to zero, thereby making the speed of the first sun gear S1 zero; the hybrid power system has an engine direct drive second gear; In combination with the clutch C1 and the first brake B1, the power output by the engine (100) is transmitted to the sixth structural element (6) via the second planetary gear. The hybrid power system has a third gear of engine direct drive.

7. The control method of the planetary gear hybrid system according to claim 4, characterized in that: Controlling the hybrid power system to switch to a power split mode, the method comprising: starting the engine (100), engaging the clutch C1, and transmitting the power output by the engine (100) to the first ring gear R1 and the second planet carrier H2; The first motor M1 can be controlled to generate electricity and the second motor M2 can be controlled to drive; or the second motor M2 can be controlled to generate electricity and the first motor M1 can be controlled to drive.

8. The control method of the hybrid power system according to claim 4, characterized in that: The hybrid power system is switched to a parallel driving mode, and the method comprises: starting the engine (100) The clutch C1 is engaged, the first motor M1 is driven, the second motor M2 is not operated, and the hybrid system has a parallel drive first gear mode; The clutch C1 is engaged, the first motor M1 is not working, the second motor M2 is driving, and the hybrid power system has a parallel drive second gear mode.

9. The control method of the hybrid power system according to claim 4, characterized in that: Controlling the hybrid power system to switch to a braking energy recovery mode, the method comprising: stopping the engine (100), engaging the second brake B2, transmitting the rotational torque to the first planetary carrier H1 and the second ring gear R2 through the sixth structural element (6), rotating the first sun gear S1 and the third sun gear S3, and rotating the first motor M1 and the second motor M2 to generate electricity.

10. The control method of the hybrid power system according to claim 4, characterized in that: Controlling the hybrid power system to switch to a parking charging mode, the method comprising: when the vehicle is parked, the sixth structural element (6) has a rotation speed of zero, the engine (100) is started, the clutch C1 is engaged, the power output by the engine (100) is transmitted to the first ring gear R1 and the second planetary carrier H2, the first sun gear S1 and the third sun gear S3 rotate, and the first motor M1 and the second motor M2 both rotate to generate electricity.

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