A multi-motor coupled electric drive control system for vehicles

Abstract

This application relates to a multi-motor coupled electric drive control system for vehicles, belonging to the field of mechatronics drive control system technology. It includes a gearbox, with its output end connected to a differential. Four sets of motors are installed at the input end of the gearbox, and these four sets of motors are coupled in parallel. A fixed-shaft electromechanical coupling structure for torque transmission is installed inside the gearbox. An oil-cooling circulation structure is installed on the gearbox to cool the gearbox and motors, optimizing their operating conditions. It also includes two controllers, with the motors electrically connected to the controllers. This application is mainly applied to the market segments of commercial heavy-duty trucks, mining trucks, and construction machinery, serving as a solution to the lack of high-power, high-efficiency power systems, particularly addressing the special operating conditions of low-speed, heavy-load, and high-frequency short-haul transportation. It optimizes the operating conditions of the engine or motor, reduces fuel consumption and emissions, and ensures good power performance.

Description

Technical Field

[0001] This application relates to the field of mechatronics drive control system technology, and in particular to a multi-motor coupled electric drive control system for vehicles. Background Technology

[0002] The main advantage and purpose of developing pure electric or hybrid vehicles is energy conservation and emission reduction. Reducing fuel consumption and emissions while ensuring good power performance is one of the mainstream development directions in the current automotive industry.

[0003] In the commercial vehicle market segments such as heavy trucks, mining trucks, and construction machinery, there is a lack of high-power, high-efficiency power system solutions. In particular, for special operating conditions such as low-speed heavy-load and high-speed short-haul transportation, the application of electric systems can effectively provide power system solutions for commercial vehicles in this field. Although the technology of converting oil to electric is less difficult and has a shorter development cycle, there are too many constraints on the boundaries of the whole vehicle, making it impossible to standardize and unify.

[0004] Currently, passenger vehicles are widely adopting 800V technology, primarily due to its high power output and fast charging speed, i.e., supercharging. However, the 800V route for commercial vehicles faces challenges in the short term due to the need to consider production costs, supply chain constraints, and the widespread adoption of supporting infrastructure such as charging stations, making true industrialization difficult.

[0005] From the perspective of controller output, the output voltage of existing controllers used in commercial vehicles is mostly non-automotive grade. This is because the voltage of commercial vehicles is generally rated at 540V, while the voltage range of automotive grade silicon carbide is currently 400-900V, and some can even reach 1200V. Therefore, if the voltage of commercial vehicles needs to be increased to the rated 750V or higher, silicon carbide systems must be adopted to meet the requirements of lightweight, high integration, and long range.

[0006] From the perspective of motors and transmissions, for commercial heavy-duty trucks, in the short term, when the motor operates below 12,000 RPM, similar to gasoline-powered vehicles, a reducer can amplify the torque of the drive motor. Multi-speed transmissions also allow the motor to operate in a more efficient speed range, providing the system with a wider speed range and greater torque. However, multi-speed transmissions have limitations in performance, operating conditions, reliability, and cost. With advancements in motor technology, speeds are increasing, and the inflection point at which vehicles achieve sustained maximum torque output is gradually shifting from low to high speeds. This means the optimal cruising speed and efficient operating range for the motor are expanding. Therefore, under low-speed, heavy-load conditions, multi-speed transmissions are not necessary to amplify the motor's efficient operating range.

[0007] In summary, considering all factors, increasing the vehicle system voltage level to 800V and adopting multiple motors + silicon carbide controllers + single-speed gearboxes is currently the best solution for high-power commercial vehicles such as heavy-duty trucks and mining trucks. Summary of the Invention

[0008] In order to optimize the working condition of the engine or motor in the electromechanical coupling system, reduce fuel consumption and emissions while ensuring good power performance, this application provides a multi-motor coupled electric drive control system for vehicles.

[0009] The technical solution of the multi-motor coupled electric drive control system for vehicles provided in this application is as follows:

[0010] A multi-motor coupled electric drive control system for vehicles includes a gearbox, the output end of which is connected to a differential, and the input end of which is provided with four sets of motors connected in parallel and coupled to each other. The gearbox is provided with a fixed-shaft electromechanical coupling structure for torque transmission, and the gearbox is provided with an oil cooling circulation structure for cooling the gearbox and motors to optimize their operating conditions.

[0011] It also includes two sets of controllers, and the motor is electrically connected to the controllers.

[0012] By adopting the above technical solution, the vehicle multi-motor coupled electric drive control system of this application is powered by an external battery pack. The controller inverts and rectifies the input current, and the current passing through the stator winding of the motor generates electromagnetic induction, thereby driving the rotor to rotate. The rotor transmits the torque to the gearbox, and through the mechanical transmission of the fixed shaft electromechanical coupling structure in the gearbox, the differential, i.e., the vehicle drive axle package, distributes the power to drive the half-shaft tires of the vehicle. When the vehicle multi-motor coupled electric drive control system of this application is running, the oil cooling circulation structure can continuously exchange heat and cool the gearbox and motor, thereby optimizing the working condition of the gearbox and motor, so as to achieve the effect of reducing fuel consumption and emissions while maintaining good power performance.

[0013] Optionally, the fixed-shaft electromechanical coupling structure includes four input shafts, four input shaft gears, an output shaft, and a large output shaft gear, with the motor, input shafts, and input shaft gears corresponding one-to-one. The input shafts are rotatably connected to the gearbox, the rotor of the motor is connected to the corresponding input shaft, the input shaft gears are sleeved on the corresponding input shaft peripheral wall, the output shaft is rotatably connected to the gearbox, the output shaft is connected to the differential, the large output shaft gear is sleeved on the output shaft peripheral wall, and the large output shaft gear is located between the four input shaft gears, with each input shaft gear meshing with the large output shaft gear.

[0014] By adopting the above technical solution, the rotor of the motor is connected to the corresponding input shaft. During the rotation of the electronic rotor, the input shaft is driven to rotate. Thus, through the meshing relationship between the input shaft gear and the large output shaft gear, the output shaft is driven to operate, thereby driving the differential to run. The fixed shaft electromechanical coupling structure of this application can independently control the operating conditions of the motor during electrical coupling, so as to control the motor to work in the most economical area, improve energy conversion efficiency and transmission efficiency.

[0015] Optionally, the rotor peripheral wall is provided with a front bearing and a rear bearing, and the rotor is rotatably connected to the motor housing through the front bearing and the rear bearing; the input shaft peripheral wall is provided with an input shaft front bearing and an input shaft rear bearing, and the input shaft is rotatably connected to the gearbox through the input shaft front bearing and the input shaft rear bearing; the output shaft peripheral wall is provided with a front tapered bearing and a rear tapered bearing, and the output shaft is rotatably connected to the gearbox through the front tapered bearing and the rear tapered bearing.

[0016] By adopting the above technical solution, front and rear bearings are installed. The front and rear input shaft bearings, as well as the front and rear tapered bearings, can effectively reduce wear during the rotation of the rotor, input shaft, and output shaft, making the rotation smoother, improving the smoothness of the transmission process, and extending the service life.

[0017] Optionally, the oil cooling circulation structure includes a gearbox oil pan, an oil pump distributor, four oil pumps, and four heat exchangers, with each of the motor, oil pump, and heat exchanger corresponding to one another. The oil pump distributor is connected to the oil outlet of the gearbox oil pan. The oil pump is installed on the outer wall of the corresponding motor and is connected to the oil outlet of the corresponding motor. The oil pump distributor is used to distribute the oil flowing out of the gearbox oil pan into the oil pump. The heat exchanger is connected to the end of the oil pump away from the oil pump distributor. The oil outlet of the heat exchanger is connected to the stator winding inside the motor housing. The rotation of the rotor drives the oil to flow into the inner hole of the input shaft of the gearbox.

[0018] By adopting the above technical solution, the lubricating oil inside the gearbox flows into the gearbox oil pan after lubricating the internal structure of the gearbox. It then enters the oil pump distributor, which distributes the lubricating oil to four oil pumps. Residual lubricating oil in the motor corresponding to each oil pump also enters the pump. The lubricating oil then enters the heat exchanger, where it is cooled. After cooling, the lubricating oil continues to be delivered to the stator windings of the corresponding motor, where it sprays and cools the stator windings. Simultaneously, it lubricates the bearings on the rotor. The lubricating oil further enters the rotor's inner bore and, during rotor rotation, follows the rotor into the inner bore of the gearbox input shaft, thus entering the gearbox and cooling and lubricating the internal parts. This forms a complete oil cooling cycle. The branched oil channels achieve active lubrication, ensuring effective cooling and lubrication of the bearings at high motor speeds. Furthermore, the integrated cooling system eliminates the need to consider sealing issues during high-speed motor shaft rotation, making it highly practical.

[0019] Optionally, the oil cooling circulation structure further includes a first temperature sensor, a first pressure sensor, a second temperature sensor, and a second pressure sensor corresponding to the four sets of motors. The first temperature sensor and the first pressure sensor are both connected to the corresponding oil pump. The first temperature sensor and the first pressure sensor are used to detect the temperature and oil pressure flowing through the oil pump, respectively. The second pressure sensor and the second temperature sensor are set at the oil outlet of the corresponding heat exchanger. The second pressure sensor and the second temperature sensor are used to monitor the oil pressure and temperature flowing through the heat exchanger.

[0020] By adopting the above technical solution, the first temperature sensor, the first pressure sensor, the second temperature sensor, and the second pressure sensor can monitor the temperature and oil pressure of the lubricating oil flowing in the oil-cooling circulation structure in real time, so as to promptly remind the driver and the vehicle controller when the temperature and oil pressure are abnormal, thereby improving the safety of the vehicle multi-motor coupled electric drive control structure of this application.

[0021] Optionally, a first filter screen is provided between the gearbox oil pan and the oil pump distributor, a second filter screen is provided between the oil outlet of the motor and the oil pump, and a fine filter screen is provided between the oil pump and the heat exchanger.

[0022] By adopting the above technical solution, the first filter screen, the second filter screen, and the fine filter screen can filter out impurities such as iron filings mixed in the lubricating oil, thereby improving the overall quality of the lubricating oil. At the same time, it can also prevent the oil pump, heat exchanger, and other components from being clogged due to excessive iron filings, making the oil cooling circulation structure of this application safer, more stable, and more efficient in operation.

[0023] Optionally, each controller includes two sets of IGBT modules, with each IGBT module corresponding to a motor. The IGBT module is electrically connected to the corresponding motor winding. Each IGBT module includes six MOSFET switching devices and one diode, which are connected in parallel.

[0024] By adopting the above technical solution, the IGBT module can control the start-up and shutdown of the motor and its operating power, so that the vehicle can use different operating modes at different driving speeds, enabling the whole vehicle to operate in a more efficient and energy-saving manner.

[0025] Optionally, the MOSFET switching device is made of SiC.

[0026] By adopting the above technical solutions, the use of SiC material in MOSFET switching devices can effectively reduce switching losses, thereby increasing the vehicle's driving range by 5-10% and improving energy conversion efficiency. At the same time, SiC has the effect of achieving lightweighting, with a smaller area, which can reduce the controller volume by about 10-40%, thereby reducing the overall vehicle cost.

[0027] Optionally, a transition plate is provided between the motor and the gearbox, and the motor is connected to the gearbox through the transition plate.

[0028] By adopting the above technical solution, a transition plate is set up for the motor to be installed, which enables quick assembly and disassembly between the motor and the gearbox, improving convenience.

[0029] Optionally, a support frame is provided on the outer wall of the motor, and the controller is assembled with the motor through the support frame.

[0030] By adopting the above technical solution, the support frame facilitates the disassembly of the controller and the motor, improving the ease of assembly. At the same time, it can also separate the controller and the motor, ensuring the safety of their respective structures.

[0031] In summary, this application includes at least one of the following beneficial technical effects:

[0032] 1. The vehicle multi-motor coupled electric drive control system of this application is powered by an external battery pack. The controller inverts and rectifies the input current. The current passing through the stator winding of the motor generates electromagnetic induction, thereby driving the rotor to rotate. The rotor transmits the rotational torque to the gearbox. After further transmission through the fixed shaft electromechanical coupling structure in the gearbox, the differential, i.e., the vehicle drive axle package, distributes the power to drive the half-shaft tires of the vehicle. When the vehicle multi-motor coupled electric drive control system of this application is running, the oil cooling circulation structure can continuously exchange heat and cool the gearbox and motor, thereby optimizing the working condition of the gearbox and motor, so as to reduce fuel consumption and emissions while maintaining good power performance.

[0033] 2. Using SiC material for MOSFET switching devices can effectively reduce switching losses, thereby increasing the vehicle's driving range by 5-10% and improving energy conversion efficiency. At the same time, SiC can achieve a lightweight effect, with a smaller area, which can reduce the controller volume by about 10-40%, thereby reducing the overall vehicle cost. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of a vehicle multi-motor coupled electric drive control system according to an embodiment of this application.

[0035] Figure 2 This is a cross-sectional view of the motor and gearbox in an embodiment of this application.

[0036] Figure 3 This is a schematic diagram of the controller structure in an embodiment of this application.

[0037] Figure 4 This is a schematic diagram of the oil cooling circulation structure in the embodiments of this application.

[0038] Figure 5 This is a schematic diagram illustrating the switching of different vehicle speed modes in an embodiment of this application.

[0039] Explanation of reference numerals in the attached drawings: 1. Oil pump; 2. Heat exchanger; 3. Controller; 4. Motor; 5. Gearbox; 6. Support frame; 7. Motor housing; 8. Rear bearing; 9. Stator winding; 10. Rotor; 11. Front bearing; 12. Transition plate; 13. Oil seal; 14. Input shaft; 15. Front bearing of input shaft; 16. Input shaft gear; 17. Rear bearing of input shaft; 18. Large gear of output shaft; 19. Rear tapered bearing; 20. Front tapered bearing; 21. Oil seal of output shaft; 22. Output shaft; 23. Fixed shaft electromechanical coupling structure; 24. Oil cooling circulation structure; 25. Gearbox oil pan; 26. Oil pump distributor; 27. First temperature sensor; 28. First pressure sensor; 29. ​​Second temperature sensor; 30. Second pressure sensor; 31. First filter screen; 32. Second filter screen; 33. Fine filter screen; 34. IGBT module; 35. MOSFET switching device; 36. Diode. Implementation

[0040] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0041] This application discloses a multi-motor coupled electric drive control system for vehicles. (Refer to...) Figure 1 and Figure 2 It includes a gearbox 5, four motors 4 and two controllers 3. A transition plate 12 is provided on one side of the gearbox 5. The four motors 4 are connected to the gearbox 5 through the transition plate 12 to facilitate quick assembly and connection of the motors 4. The four sets of motors 4 are coupled in parallel. Each motor housing 7 is provided with a stator winding 9, which is connected to a rotor 10. The rotor 10 is provided with a front bearing 11 and a rear bearing 8 on its peripheral wall. The rotor 10 is rotatably connected to the motor housing 7 through the front bearing 11 and the rear bearing 8.

[0042] Reference Figure 1 and Figure 2 The gearbox 5 is equipped with a fixed-shaft electromechanical coupling structure 23 for torque transmission. The fixed-shaft electromechanical coupling structure 23 includes four input shafts 14, four input shaft gears 16, an output shaft 22, and an output shaft large gear 18. The motor 4, the input shafts 14, and the input shaft gears 16 are arranged in a one-to-one correspondence.

[0043] Reference Figure 1 and Figure 2The input shaft 14 is provided with a front bearing 15 and a rear bearing 17 on its peripheral wall. The input shaft 14 is rotatably connected to the gearbox 5 through the front bearing 15 and the rear bearing 17. The end of the rotor 10 extending out of the motor housing 7 is connected to the corresponding input shaft 14 through a spline, thereby rotating the input shaft 14. The output shaft 22 is provided on the inner wall of the gearbox 5 on the side away from the motor 4. One end of the output shaft 22 extends out of the gearbox 5 and is connected to the drive axle housing (differential). The peripheral wall of the output shaft 22 located inside the gearbox 5 is provided with a front tapered bearing 20 and a rear tapered bearing 19. The output shaft 22 is rotatably connected to the gearbox 5 through the front tapered bearing 20 and the rear tapered bearing 19.

[0044] Reference Figure 1 and Figure 2 The input shaft gear 16 is sleeved on the circumferential wall of the corresponding input shaft 14, and the output shaft large gear 18 is sleeved on the circumferential wall of the output shaft 22. The output shaft large gear 18 is located between the four input shaft gears 16, and each input shaft gear 16 meshes with the output shaft large gear 18, thereby enabling power transmission.

[0045] Reference Figure 1 and Figure 2 The outer wall of the motor 4 is equipped with a support frame 6. The controller 3 is assembled with the motor 4 through the support frame 6. Each controller 3 is electrically connected to two motors 4. In actual use, the motor 4 is connected to a battery pack. The rated 600V / 282kWh battery pack provides a continuous 200A current through the DC bus. After being inverted and rectified by the two controllers 3, the current flows through the stator winding 9 of the motor 4, generating electromagnetic induction to drive the rotor 10 to rotate. The rotor 10 is splined and toothedly aligned with the input shaft 14 of the gearbox 5. The torque output from the rotor 10 is transmitted to the output shaft 22 through the meshing of the input shaft gear 16 and the output shaft large gear 18. Finally, the output shaft 22 is connected to the external drive shaft to distribute power to the drive axle package to drive the half-shaft tires of the vehicle. When electrically coupled, the fixed shaft electromechanical coupling structure 23 can independently control the engine operating conditions and control the engine to work in the most economical range. When torque coupled, the engine torque is controllable, but the speed cannot be independently controlled. Therefore, the engine can be operated in the economical range by controlling the torque of the motor 4.

[0046] Reference Figure 1 and Figure 3Each controller 3 includes two IGBT modules 34, with each IGBT module 34 corresponding to a motor 4. The IGBT modules 34 are electrically connected to the corresponding motor windings 4. Each IGBT module 34 includes six SiC silicon carbide MOSFET switching devices 35 and one diode 36. The six SiC silicon carbide MOSFET switching devices 35 and the diode 36 are connected in parallel. The MOSFET switching devices 35 are made of SiC, which can reduce switching losses and increase the driving range by 5-10%. Thanks to the superior performance of SiC, the size of the controller 3 can be reduced by about 10% to 40%, thus reducing the overall vehicle cost.

[0047] Furthermore, using the controller 3 of this application, the total of 24 SiC silicon carbide MOSFET switching devices 35 are named Q1-Q24, and the 4 diodes 36 are named T1-T4 respectively. Correspondingly, the stator windings 9 of the four motors 4 are also named 1#-4# motor 4 windings respectively.

[0048] Reference Figure 3 and Figure 5 When the vehicle is traveling at high speed (speed n≥45km / h), T1 & T3 are turned on, T2 & T4 are turned off, and the fourth winding of motors #1 and #3 participates in operation (partial winding), while the fourth winding of motors #2 and #4 stops operating. This mode reduces the number of motors #4 participating in operation, which reduces the back electromotive force of the windings and decreases the field weakening depth, allowing the system to maintain constant power and high efficiency operation.

[0049] When the vehicle is traveling at low speed (speed n < 25 km / h), T1 & T3 are off, T2 & T4 are on, and the four windings of motors 1 to 4 work simultaneously (all windings). This mode increases the number of motors 4 participating in operation, that is, increases the number of winding turns, and improves the torque output capability of the entire system's motors 4.

[0050] When the vehicle speed is 25≤n<45km / h, T2&T4 are turned off, and the capacitor and battery pack are charged through the parasitic body diode 36 of the 12 MOSFETs Q7-Q12 and Q19-Q24, thus realizing energy recovery.

[0051] Reference Figure 2 and Figure 4 The gearbox 5 is equipped with an oil cooling circulation structure 24 to cool the gearbox 5 and the motor 4 and optimize their working conditions. The oil cooling circulation structure 24 includes a gearbox oil pan 25, an oil pump distributor 26, four oil pumps 1 and four heat exchangers 2, wherein the motor 4, the oil pumps 1 and the heat exchangers 2 are arranged in a one-to-one correspondence.

[0052] Reference Figure 4The gearbox oil pan 25 is connected to the oil outlet of the gearbox 5. The oil pump 1 is installed on the outer wall of the corresponding motor 4 and is connected to the oil outlet of the corresponding motor 4. A first filter screen 31 is provided between the gearbox oil pan 25 and the oil pump distributor 26 to filter impurities such as iron filings. The oil pump distributor 26 is used to distribute the oil flowing out of the gearbox oil pan 25 to the oil pump 1. At the same time, the oil outlet of each motor 4 is also connected to the corresponding oil pump 1. A second filter screen 32 is provided between the oil outlet of the motor 4 and the oil pump 1, so that the lubricating oil remaining in the motor housing 7 can also enter the corresponding oil pump 1.

[0053] Reference Figure 4 The heat exchanger 2 is connected to the end of the oil pump 1 away from the oil pump distributor 26. A fine filter screen 33 is provided between the oil pump 1 and the heat exchanger 2 to further filter impurities such as iron filings to prevent blockage in the heat exchanger 2. The oil outlet end of the heat exchanger 2 is connected to the stator winding 9 in the motor housing 7. The rotation of the rotor 10 drives the oil to flow into the inner hole of the input shaft 14 of the gearbox 5.

[0054] Reference Figure 4 The oil cooling circulation structure 24 also includes a first temperature sensor 27, a first pressure sensor 28, a second temperature sensor 29, and a second pressure sensor 30, which are set for the four sets of motors 4. The first temperature sensor 27 and the first pressure sensor 28 are both connected to the corresponding oil pump 1. The first temperature sensor 27 and the first pressure sensor 28 are used to detect the temperature and oil pressure flowing through the oil pump 1, respectively. The second pressure sensor 30 and the second temperature sensor 29 are set at the oil outlet end of the corresponding heat exchanger 2. The second pressure sensor 30 and the second temperature sensor 29 are used to monitor the oil pressure and temperature flowing through the heat exchanger 2.

[0055] In the specific implementation process, the motor 4 adopts spray cooling and active bearing lubrication. An oil seal 13 is installed at the input shaft 14 and an output shaft oil seal 21 is installed at the output shaft 22. An integrated oil passage design is adopted, and the rotor shaft 10 of the motor 4 and the input shaft 14 of the gearbox 5 can be made into one piece. The bearing chamber is designed with branch oil passages to realize the active lubrication function, which ensures the cooling and lubrication effect of the bearing when the motor 4 is at high speed. In addition, the integrated cooling eliminates the need to consider the sealing problem when the motor 4 shaft rotates at high speed. The pressure and temperature of the system are monitored at different parts. The cooling medium is a gearbox-specific oil, and different cooling points have different flow requirements. On the other hand, to prevent excessive internal pressure of the cooling and lubrication system, a safety relief valve is installed on the oil pump 1.

[0056] Furthermore, this application adopts a four-motor parallel architecture and a multi-mode switching control strategy, which can flexibly switch between the following five different working modes to improve system efficiency and save energy.

[0057] (1) EV mode: Under low speed conditions (10~25km / h), the engine does not work in this mode because the internal combustion engine provides power with low efficiency. Under single-axle drive (such as 4×2 models), the vehicle is driven by 4 motors (full winding) or 2 motors (partial winding); when the vehicle is starting at a low speed below 25km / h or under specific conditions and when going uphill with heavy load, the 4 motors are controlled to output power simultaneously; at high speeds above 45km / h, only 2 of the motors are controlled to output power; at 25~45km / h, the vehicle enters the shift range and the 2 motors or 4 motors output power.

[0058] (2) Series mode (range-extended models): When the battery power is insufficient under low-speed conditions, the hybrid system switches to a series architecture, and the engine (diesel or methanol) drives the generator to provide power to the drive motor. At this time, the hybrid system is controlled by two sets of dual-motor controllers to control the energy flow, so as to ensure that the engine stays in the high-efficiency operating range and supplies power to the battery and drive motor.

[0059] (3) Engine direct drive mode (hybrid models - oil-electric or methanol & electric): The engine has high working efficiency at medium and high speeds. The series mode requires driving the motor and adds some transmission mechanical devices, resulting in energy waste. The hybrid system adopts engine direct drive mode, which can reduce fuel consumption by 10%~15% compared with the series mode.

[0060] (4) Parallel mode (hybrid or range-extended models): Under dual-axle drive (such as 6×4 models), when heavily loaded uphill (16%-30%) or accelerating rapidly, the diesel or methanol engine maintains its high-efficiency operating range to directly drive one axle wheel, while the other axle is provided with auxiliary power by the 4-motor drive system.

[0061] (5) Energy recovery mode: When decelerating, braking, or when the vehicle is heavily loaded and going downhill, or when shifting gears at speeds between 25 and 45 km / h, the system can convert some kinetic energy into electrical energy. Two of the motors act as generators to recover energy and charge the battery (only for single-axle drive 4×2 models), reducing energy waste caused by friction. In dual-axle drive (such as 6×4 models), four motors on one axle drive the vehicle, while four motors on the other axle act as generators to recover energy and charge the battery pack.

[0062] Among them, modes (1) and (5) are applicable to pure electric vehicles; modes (1) to (5) are applicable to hybrid or range-extended vehicles. Whether the vehicle is a 4×2 single-axle drive vehicle or a 6×4 dual-axle drive vehicle is defined by the vehicle manufacturer.

[0063] The implementation principle of the multi-motor coupled electric drive control system for vehicles according to this application is as follows: an external battery pack supplies power to the multi-motor coupled electric drive control system of this application. The controller 3 inverts and rectifies the input current. The current in the stator winding 9 of the motor 4 generates electromagnetic induction, thereby driving the rotor 10 to rotate. The rotor 10 transmits the rotational torque to the gearbox 5. After further transmission through the fixed shaft electromechanical coupling structure 23 in the gearbox 5, the differential, i.e., the vehicle drive axle package, distributes the power to drive the half-shaft tires of the vehicle. When the multi-motor coupled electric drive control system of this application is running, the oil cooling circulation structure 24 can continuously exchange heat and cool the gearbox 5 and the motor 4, thereby optimizing the working condition of the gearbox 5 and the motor 4, so as to reduce fuel consumption and emissions while maintaining good power performance.

[0064] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A multi-motor coupled electric drive control system for vehicles, characterized in that: The gearbox (5) includes a gearbox (5) whose output end is connected to a differential. The gearbox (5) has four sets of motors (4) at its input end, which are connected in parallel and coupled to each other. The gearbox (5) has a fixed-shaft electromechanical coupling structure (23) for torque transmission. The gearbox (5) has an oil cooling circulation structure (24) for cooling the gearbox (5) and the motors (4) to optimize their working conditions. The fixed-axis electromechanical coupling structure (23) includes four input shafts (14), four input shaft gears (16), an output shaft (22), and an output shaft large gear (18). The motor (4), input shafts (14), and input shaft gears (16) correspond one-to-one. The input shafts (14) are rotatably connected to the gearbox (5). The rotor (10) of the motor (4) is connected to the corresponding input shaft (14). The input shaft gears (16) are sleeved on the peripheral wall of the corresponding input shafts (14). The output shaft (22) is rotatably connected to the gearbox (5). The output shaft (22) is connected to the differential. The output shaft large gear (18) is sleeved on the peripheral wall of the output shaft (22). The output shaft large gear (18) is located between the four input shaft gears (16), and each input shaft gear (16) meshes with the output shaft large gear (18). The oil cooling circulation structure (24) includes a gearbox oil pan (25), an oil pump distributor (26), four oil pumps (1) and four heat exchangers (2). The motor (4), oil pumps (1) and heat exchangers (2) correspond one-to-one. The oil pump distributor (26) is connected to the oil outlet of the gearbox oil pan (25). The oil pumps (1) are located on the outer wall of the corresponding motors (4). The oil pumps (1) are connected to the oil outlet of the corresponding motors (4). The oil pump distributor (26) is used to distribute the oil flowing out of the gearbox oil pan (25) to the oil pumps (1). The heat exchangers (2) are connected to the end of the oil pumps (1) away from the oil pump distributor (26). The oil outlet of the heat exchangers (2) is connected to the stator windings (9) inside the motor housing (7). The rotor (10) rotates and drives the oil to flow into the inner hole of the input shaft (14) of the gearbox (5). The oil cooling circulation structure (24) also includes a first temperature sensor (27), a first pressure sensor (28), a second temperature sensor (29), and a second pressure sensor (30) corresponding to the four sets of motors (4). The first temperature sensor (27) and the first pressure sensor (28) are both connected to the corresponding oil pump (1). The first temperature sensor (27) and the first pressure sensor (28) are used to detect the temperature and oil pressure flowing through the oil pump (1), respectively. The second pressure sensor (30) and the second temperature sensor (29) are set at the oil outlet of the corresponding heat exchanger (2). The second pressure sensor (30) and the second temperature sensor (29) are used to monitor the oil pressure and temperature flowing through the heat exchanger (2). It also includes two sets of controllers (3), and the motor (4) is electrically connected to the controllers (3); each controller (3) includes two sets of IGBT modules (34), and the IGBT modules (34) and the motor (4) correspond one to one. The IGBT modules (34) are electrically connected to the windings of the corresponding motor (4). Each IGBT module (34) includes 6 MOSFET switching devices (35) and 1 diode (36), and the MOSFET switching devices (35) and the diode (36) are arranged in parallel.

2. The vehicle multi-motor coupled electric drive control system according to claim 1, characterized in that: The rotor (10) is provided with a front bearing (11) and a rear bearing (8) on its peripheral wall. The rotor (10) is rotatably connected to the motor housing (7) through the front bearing (11) and the rear bearing (8). The input shaft (14) is provided with a front bearing (15) and a rear bearing (17) on its peripheral wall. The input shaft (14) is rotatably connected to the gearbox (5) through the front bearing (15) and the rear bearing (17). The output shaft (22) is provided with a front tapered bearing (20) and a rear tapered bearing (19) on its peripheral wall. The output shaft (22) is rotatably connected to the gearbox (5) through the front tapered bearing (20) and the rear tapered bearing (19).

3. The vehicle multi-motor coupled electric drive control system according to claim 1, characterized in that: A first filter screen (31) is provided between the gearbox oil pan (25) and the oil pump distributor (26), a second filter screen (32) is provided between the oil outlet end of the motor (4) and the oil pump (1), and a fine filter screen (33) is provided between the oil pump (1) and the heat exchanger (2).

4. The vehicle multi-motor coupled electric drive control system according to claim 1, characterized in that: The MOS transistor switching device (35) is made of SiC.

5. A vehicle multi-motor coupled electric drive control system according to claim 1, characterized in that: A transition plate (12) is provided between the motor (4) and the gearbox (5), and the motor (4) is connected to the gearbox (5) through the transition plate (12).

6. A vehicle multi-motor coupled electric drive control system according to claim 1, characterized in that: The motor (4) is provided with a support frame (6) on its outer wall, and the controller (3) is assembled with the motor (4) through the support frame (6).

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