Torque distribution method for a hybrid system

Abstract

A torque distribution method for a hybrid power system, when a vehicle loaded with the hybrid power system meets an activation condition of distributing torque in a parallel driving mode, an engine target torque, a generator target torque and a driving motor target torque are obtained in the following manner: 1) determining a current engine target torque according to a current engine gear ratio, an engine actual speed, a wheel end demand torque and an engine target torque economy control lookup table; 2) determining a current generator target torque according to a generator target torque limit maximum value, a generator target torque limit minimum value and a generator demand torque original value; and 3) determining a current driving motor target torque according to a high-voltage battery maximum discharge power, an accessory consumption power, an engine actual torque, a generator actual torque, a clutch actual torque, a driving motor maximum limit torque, a driving motor minimum limit torque, a wheel end demand torque and a driving motor actual speed.

Description

Technical Field

[0001] This invention relates to the field of hybrid power, and more specifically to a torque distribution method for a hybrid power system. Background Technology

[0002] like Figure 1 The hybrid system shown integrates a gasoline power system with an electric drive system, allowing the vehicle to be driven by both the engine and the drive motor (series drive mode) or by each motor independently (parallel drive mode). In parallel drive mode, the engine's output power is directly applied to the drive wheels without undergoing a mechanical-to-electrical energy conversion process, meaning the engine's output energy utilization is high. When the engine's operating parameters are within their optimal range, the fuel economy of parallel drive mode is higher than that of series drive mode. Therefore, rationally distributing the output torque of the hybrid system in parallel drive mode is crucial for improving the overall fuel economy of the vehicle. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a torque distribution method for hybrid power systems. By improving the accuracy of torque distribution in parallel drive mode, this method enhances vehicle energy utilization and driving comfort.

[0004] The objective of this invention is achieved through the following solution: a torque distribution method for a hybrid power system, wherein when a vehicle equipped with a hybrid power system meets the activation conditions for torque distribution in parallel drive mode, the current target torque of the engine, the target torque of the generator, and the target torque of the drive motor of the vehicle are obtained in the following manner:

[0005] 1) Engine target torque:

[0006] 1-1) Based on the current actual engine speed and the engine target torque economic control lookup table, determine the engine target torque threshold range corresponding to the current actual engine speed;

[0007] 1-2) Determine the current engine target torque based on the current engine gear ratio, wheel end torque requirement, and the engine target torque threshold range obtained in step 1-1);

[0008] 2) Generator target torque:

[0009] 2-1) Calculate the maximum and minimum target torque limits of the generator based on the maximum charging power of the high-voltage battery, the maximum discharging power of the high-voltage battery, the power consumed by the accessories, and the actual speed of the generator;

[0010] 2-2) Calculate the original value of the generator's required torque based on the required torque at the wheel end and the actual torque output by the engine to the wheel end;

[0011] 2-3) Determine the current generator target torque based on the maximum generator target torque limit, the minimum generator target torque limit, and the original generator required torque value;

[0012] 3) Target torque of the drive motor:

[0013] 3-1) Calculate the maximum limiting torque and minimum limiting torque of the drive motor based on the maximum discharge power of the high-voltage battery, the maximum charging power of the high-voltage battery, and the actual speed of the generator.

[0014] 3-2) Calculate the original value of the required torque of the drive motor based on the required torque at the wheel end;

[0015] 3-3) Determine the current target torque of the drive motor based on the maximum limit torque of the drive motor, the minimum limit torque of the drive motor, and the original value of the required torque of the drive motor.

[0016] Preferably, the activation conditions are as follows:

[0017] ① The car's key switch is in the ON position;

[0018] ②The vehicle's powertrain system is in an active state;

[0019] ③ The gear shift lever on the car's gear shift panel is in the D position;

[0020] ④ The vehicle operates in parallel drive mode.

[0021] Preferably, the engine target torque economic control lookup table includes several engine target torque threshold ranges corresponding to different engine speeds. This engine target torque economic control lookup table is obtained through vehicle testing based on vehicle fuel economy standards.

[0022] Preferably, based on the current engine gear ratio, wheel-end torque requirement, and the engine target torque threshold range determined in step 1-1), the mathematical expression for the current engine target torque is determined as follows:

[0023] T eng_req =MAX[T eng_min MIN((T) whl_req / r eng_gear ),T eng_max )]

[0024] In the formula, T eng_req For the current engine target torque, T eng_min T is the lower limit of the engine's target torque threshold range.whl_req To meet the torque requirements at the wheel end, T eng_max r is the upper limit of the engine's target torque threshold range. eng_gear This refers to the current engine gear ratio.

[0025] Preferably, the mathematical expression for determining the current generator target torque based on the maximum generator target torque limit, the minimum generator target torque limit, and the original generator demand torque is as follows:

[0026] T gen_req =MAX[T gen_min MIN(T) gen_req_raw ,T gen_max )]

[0027] In the formula, T gen_req T is the target torque of the generator. gen_min T is the minimum target torque limit for the generator. gen_max T is the maximum target torque limit for the generator. gen_req_raw This represents the original value of the generator's required torque.

[0028] Preferably, the specific method for calculating the original value of the generator's required torque based on the wheel-end required torque and the actual torque output by the engine to the wheel-end is as follows:

[0029] ① Calculate the actual torque output from the car engine to the wheel ends using the following formula:

[0030] The actual torque output by the engine to the wheels = the actual torque of the engine × the gear ratio corresponding to the current gear of the transmission.

[0031] ② Calculate the original value of the generator's required torque based on the required torque at the wheel end and the actual torque output from the engine to the wheel end:

[0032] If the actual torque output by the engine to the wheel ends is greater than the torque required by the wheel ends, then the original value of the generator's required torque is calculated according to the following formula:

[0033] T gen_req_raw =-((T) eng_act *r gear -T whl_req ) / r eng2gen

[0034] In the formula, T gen_req_raw T represents the original value of the generator's required torque. eng_act r represents the actual torque of the engine. gear T represents the gear ratio corresponding to the current gear in the transmission. whl_req To meet the torque requirements at the wheel end, r eng2gen This refers to the transmission ratio between the engine and the generator;

[0035] If the actual torque output by the engine to the wheel end is less than or equal to the torque required by the wheel end, then the original value of the torque required by the generator is zero.

[0036] Preferably, the maximum and minimum target torque limits for the generator are calculated according to the following formulas:

[0037] T gen_max =P batt_dischrg_max / (N gen_spd ×9550)

[0038] T gen_min =-[(P batt_charge_max +P acsy ) / (N gen_spd ×9550)]

[0039] In the formula, T gen_max T is the maximum target torque limit for the generator. gen_min P is the minimum target torque limit for the generator. batt_dischrg_max N represents the maximum discharge power of the high-voltage battery. gen_spd P is the actual speed of the generator. acsy For the power consumed by the accessory, P batt_charge_max This represents the maximum charging power of the high-voltage battery.

[0040] Preferably, the maximum limiting torque and the minimum limiting torque of the drive motor are calculated according to the following formula:

[0041] T trac_max =(P batt_discharg_max +P gen -P acsy ) / (N trac_spd ×r trac_gear ×9550)

[0042] T trac_min =-[(P batt_chrg_max +P acsy ) / (N trac_spd ×r trac_gear ×9550)]

[0043] In the formula, T trac_max T is the maximum limiting torque of the drive motor. trac_min P is the minimum limiting torque for the drive motor. batt_discharg_max P represents the maximum discharge power of the high-voltage battery. batt_chrg_max P represents the maximum charging power of the high-voltage battery. gen P is the generator's power output. acsy Power consumed by the accessory, N trac_spd r is the actual speed of the drive motor. trac_gear This refers to the speed ratio corresponding to the current gear of the drive motor;

[0044] Preferably, the original value of the required torque of the drive motor is calculated in the following manner:

[0045] When the required torque at the wheel end is ≥0, the original value of the required torque of the drive motor is calculated according to the following formula:

[0046] T trac_req_raw =(T whl_req -MIN[(T eng_act +T gen_act / r eng2gen ),T clu_act ]×r eng_gear ) / r trac_gear

[0047] In the formula, T trac_req_raw T is the original value of the torque required by the drive motor. whl_req To meet the torque requirements at the wheel end, T eng_act T represents the actual torque of the engine. gen_act r is the actual torque of the generator. eng2gen T is the transmission ratio between the engine and the generator. clu_act r is the actual torque of the clutch. eng_gear Given the current engine gear ratio, r trac_gear This refers to the speed ratio corresponding to the current gear of the drive motor.

[0048] When the required torque at the wheel end is less than 0, the original value of the required torque of the drive motor is calculated according to the following formula:

[0049] T trac_req_raw =MIN(0,T) whl_req / r trac_gear )

[0050] In the formula, T trac_req_raw T is the original value of the torque required by the drive motor. whl_req To meet the torque requirements at the wheel end, r trac_gear This refers to the speed ratio corresponding to the current gear of the drive motor.

[0051] Preferably, the specific method for determining the current target torque of the drive motor based on the maximum limiting torque of the drive motor, the minimum limiting torque of the drive motor, and the original value of the required torque of the drive motor is as follows:

[0052] T trac_req =MAX[T trac_min MIN(T) trac_req_raw ,T trac_max )]

[0053] In the formula, T trac_req To drive the target torque of the motor, T trac_min T is the minimum limiting torque for the drive motor.trac_req_raw T is the original value of the torque required by the drive motor. trac_max This is the maximum limiting torque for the drive motor.

[0054] The advantage of this invention is that by using fuzzy control theory to precisely adjust the target torque of the engine, generator, and drive motor in the parallel drive mode of the hybrid power system, the safety and stability of the vehicle under downhill braking conditions are greatly improved, the efficiency of vehicle braking energy recovery is increased, thereby improving the vehicle's range and driving comfort. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the hybrid power system described in this invention;

[0056] Figure 2 This is a flowchart of the present invention;

[0057] Figure 3 This is a flowchart for determining the current target torque of the engine in this invention;

[0058] Figure 4 This is a flowchart for determining the current generator target torque in this invention;

[0059] Figure 5 This is a flowchart for determining the current target torque of the drive motor in this invention. Detailed Implementation

[0060] like Figure 1 The diagram shown is a structural schematic of a hybrid power system for implementing the present invention. The hybrid power system includes an engine 1, a clutch 2, a generator 3, a gearbox 4, a drive motor 5, a reducer 6, wheels 8, and a high-voltage battery 9. The output voltage of the high-voltage battery 9 is generally greater than the safe voltage of 60V, but less than 1000V.

[0061] The engine 1 is connected to the generator 3 via a first-stage reduction gear. The engine 1 and the generator 3 are connected to the input shaft of the gearbox 4 via a clutch 2. The drive motor 5 is coupled to the reducer via a first-stage reduction gear. The output end of the gearbox 4 is connected to the wheel 8 via the reducer 6. The high-voltage battery 9 is connected to the generator 3 and the drive motor 5 via high-voltage lines.

[0062] In this embodiment, the vehicle equipped with the above-mentioned hybrid power system needs to acquire the following signals during operation:

[0063] ① The vehicle control unit obtains the current actual engine speed and actual engine torque from the engine control unit via the CAN bus;

[0064] ②The vehicle control unit obtains the current actual generator speed, actual generator torque, and actual drive motor speed from the motor control unit via the CAN bus;

[0065] ③ The vehicle control unit obtains the maximum discharge power and maximum charging power of the high-voltage battery from the high-voltage battery control power supply via the CAN bus;

[0066] ④ The vehicle control unit obtains the required wheel-end torque from the internal driving intention module;

[0067] ⑤ The vehicle control unit obtains the power consumed by the accessories from the internal energy management module.

[0068] like Figures 2 to 5 As shown, a torque distribution method for a hybrid power system first determines whether the current vehicle meets the activation conditions for torque distribution in parallel drive mode. The activation conditions are as follows:

[0069] ① The car's key switch is in the ON position;

[0070] ②The vehicle's powertrain system is in an active state;

[0071] ③ The gear shift lever on the car's gear shift panel is in the D position;

[0072] ④ The vehicle operates in parallel drive mode.

[0073] When a vehicle equipped with a hybrid system meets the above activation conditions, the vehicle's current target engine torque, generator target torque, and drive motor target torque are obtained as follows:

[0074] 1) Engine target torque:

[0075] 1-1) Based on the current actual engine speed and the engine target torque economic control lookup table, determine the engine target torque threshold range corresponding to the current actual engine speed;

[0076] In this embodiment, as shown in Table 1, the engine target torque economic control lookup table includes several engine target torque threshold ranges corresponding to different engine speeds. This engine target torque economic control lookup table is obtained through vehicle testing based on vehicle fuel economy standards.

[0077] Table 1 Engine Target Torque Economic Control Lookup Table

[0078]

[0079] The target torque threshold range for each engine speed in the engine target torque economic control lookup table refers to the range within which the target torque of the engine at that engine speed falls within the corresponding target torque threshold range. This indicates that the vehicle meets the fuel economy requirements for that vehicle. If the target torque of the engine at that engine speed exceeds the target torque threshold range, then the vehicle does not meet the fuel economy requirements for that vehicle.

[0080] 1-2) Determine the current engine target torque based on the current engine gear ratio, wheel end torque requirement, and the engine target torque threshold range obtained in step 1-1). The specific mathematical expression is as follows:

[0081] T eng_req =MAX[T eng_min MIN((T whl_req / r eng_gear ),T eng_max )]

[0082] In the formula, T eng_req For the current engine target torque, T eng_min T is the lower limit of the engine's target torque threshold range. whl_req To meet the torque requirements at the wheel end, T eng_max r is the upper limit of the engine's target torque threshold range. eng_gear This refers to the current engine gear ratio.

[0083] The above formula illustrates that, in this embodiment, the engine target torque, calculated using the wheel-end demand torque and the current engine gear ratio, should first be used to determine the control value. Then, the engine target torque control value should be compared with the upper and lower limits of the engine target torque threshold range.

[0084] If the engine target torque judgment control value is greater than the upper limit of the engine target torque threshold range, then the upper limit of the engine target torque threshold range is used as the current engine target torque.

[0085] If the engine target torque judgment control value is less than the lower limit of the engine target torque threshold range, then the lower limit of the engine target torque threshold range is used as the current engine target torque.

[0086] If the upper limit of the engine target torque threshold range is greater than or equal to the engine target torque judgment control value, and greater than or equal to the lower limit of the engine target torque threshold range, then the engine target torque judgment control value is used as the current engine target torque. That is, in order to meet the fuel economy requirements of the vehicle, the current engine target torque must be within the engine target torque threshold range corresponding to the current engine actual speed.

[0087] 2) Generator target torque:

[0088] 2-1) Calculate the maximum and minimum target torque limits of the generator based on the maximum charging power of the high-voltage battery, the maximum discharging power of the high-voltage battery, the power consumed by the accessories, and the actual speed of the generator. The maximum and minimum target torque limits of the generator are calculated according to the following formulas:

[0089] T gen_max =P batt_dischrg_max / (N gen_spd ×9550)

[0090] T gen_min =-[(P batt_charge_max +P acsy ) / (N gen_spd ×9550)]

[0091] In the formula, T gen_max T is the maximum target torque limit for the generator. gen_min P is the minimum target torque limit for the generator. batt_dischrg_max N represents the maximum discharge power of the high-voltage battery. gen_spd P is the actual speed of the generator. acsy For the power consumed by the accessory, P batt_charge_max This represents the maximum charging power of the high-voltage battery.

[0092] 2-2) The vehicle control unit calculates the raw value of the generator's required torque based on the wheel-end torque demand and the actual torque output from the engine to the wheel-ends. The specific method is as follows:

[0093] ① Calculate the actual torque output from the car engine to the wheel ends using the following formula:

[0094] The actual torque output by the engine to the wheels = the actual torque of the engine × the gear ratio corresponding to the current gear of the transmission.

[0095] ② Calculate the original value of the generator's required torque based on the required torque at the wheel end and the actual torque output from the engine to the wheel end:

[0096] If the actual torque output by the engine to the wheel ends is greater than the torque required at the wheel ends, then the original value of the generator's required torque is calculated according to the following formula:

[0097] T gen_req_raw =-((T) eng_act *r gear -T whl_req ) / r eng2gen

[0098] In the formula, T gen_req_raw T represents the original value of the generator's required torque. eng_actr represents the actual torque of the engine. gear T represents the gear ratio corresponding to the current gear in the transmission. whl_req To meet the torque requirements at the wheel end, r eng2gen This refers to the transmission ratio between the engine and the generator;

[0099] The excess torque that the engine actually outputs to the wheel ends is allocated to the generator for power generation;

[0100] If the actual torque output by the engine to the wheel end is less than or equal to the torque required by the wheel end, then the original value of the torque required by the generator is zero.

[0101] 2-3) The vehicle control unit determines the current generator target torque based on the maximum generator target torque limit, the minimum generator target torque limit, and the original generator torque demand value, as follows:

[0102] T gen_req =MAX[T gen_min MIN(T) gen_req_raw ,T gen_max )]

[0103] In the formula, T gen_req T is the target torque of the generator. gen_min T is the minimum target torque limit for the generator. gen_max T is the maximum target torque limit for the generator. gen_req_raw This represents the original value of the generator's required torque.

[0104] The above formula explains that, in this embodiment, when the original value of the generator's required torque is greater than the maximum value of the generator's target torque limit, the maximum value of the generator's target torque limit is taken as the current generator target torque.

[0105] When the original value of the generator's required torque is less than the minimum value of the generator's target torque limit, the minimum value of the generator's target torque limit will be used as the current generator target torque.

[0106] When the minimum value of the generator target torque limit is less than or equal to the original value of the generator demand torque and less than or equal to the maximum value of the generator target torque limit, the original value of the generator demand torque will be used as the current generator target torque.

[0107] 3) The vehicle control unit calculates the target torque of the drive motor according to the following method based on the maximum discharge power of the high-voltage battery, the power consumed by accessories, the actual torque of the engine, the actual torque of the generator, the actual torque of the clutch, the maximum limiting torque of the drive motor, the minimum limiting torque of the drive motor, the required torque at the wheel end, and the actual speed of the drive motor:

[0108] 3-1) Calculate the maximum limiting torque and minimum limiting torque of the drive motor based on the maximum discharge power of the high-voltage battery, the maximum charging power of the high-voltage battery, and the actual speed of the generator. The maximum limiting torque and minimum limiting torque of the drive motor are calculated according to the following formulas:

[0109] T trac_max =(P batt_discharg_max +P gen -P acsy ) / (N trac_spd ×r trac_gear ×9550)

[0110] T trac_min =-[(P batt_chrg_max +P acsy ) / (N trac_spd ×r trac_gear ×9550)]

[0111] In the formula, T trac_max T is the maximum limiting torque of the drive motor. trac_min P is the minimum limiting torque for the drive motor. batt_discharg_max P represents the maximum discharge power of the high-voltage battery. batt_chrg_max P represents the maximum charging power of the high-voltage battery. gen P is the generator's power output. acsy Power consumed by the accessory, N trac_spd r is the actual speed of the drive motor. trac_gear This refers to the speed ratio corresponding to the current gear of the drive motor;

[0112] The power consumption P of the accessory acsy The power consumed by the thermal management system is controlled by the vehicle control unit from the internal energy management module.

[0113] 3-2) Calculate the original value of the required torque of the drive motor based on the required torque at the wheel end. The original value of the required torque of the drive motor is calculated in the following manner:

[0114] When the required torque at the wheel end is ≥0, the original value of the required torque of the drive motor is calculated according to the following formula: T trac_req_raw =(T whl_req -MIN[(T eng_act +T gen_act / r eng2gen ),T clu_act ]×r eng_gear ) / r trac_gear

[0115] In the formula, T trac_req_raw T is the original value of the torque required by the drive motor. whl_req To meet the torque requirements at the wheel end, T eng_actT represents the actual torque of the engine. gen_act r is the actual torque of the generator. eng2gen T is the transmission ratio between the engine and the generator. clu_act r is the actual torque of the clutch. eng_gear Given the current engine gear ratio, r trac_gear This refers to the speed ratio corresponding to the current gear of the drive motor.

[0116] When the required torque at the wheel end is less than 0, the drive motor performs energy recovery. The original value of the required torque of the drive motor is then calculated according to the following formula:

[0117] T trac_req_raw =MIN(0,T) whl_req / r trac_gear )

[0118] In the formula, T trac_req_raw T is the original value of the torque required by the drive motor. whl_req To meet the torque requirements at the wheel end, r trac_gear This refers to the speed ratio corresponding to the current gear of the drive motor;

[0119] 3-3) Determine the current target torque of the drive motor based on the maximum limit torque, minimum limit torque, and original value of the required torque of the drive motor. The specific method is as follows:

[0120] T trac_req =MAX[T trac_min MIN(T) trac_req_raw ,T trac_max )]

[0121] In the formula, T trac_req To drive the target torque of the motor, T trac_min T is the minimum limiting torque for the drive motor. trac_req_raw T is the original value of the torque required by the drive motor. trac_max This is the maximum limiting torque for the drive motor.

[0122] The above formula illustrates that, in this embodiment, when the original value of the required torque of the drive motor is greater than or equal to the maximum limiting torque of the drive motor, the maximum limiting torque of the drive motor is taken as the target torque of the drive motor.

[0123] When the original value of the required torque of the drive motor is less than or equal to the minimum limit torque of the drive motor, the minimum limit torque of the drive motor shall be used as the target torque of the drive motor.

[0124] When the minimum limiting torque of the drive motor is less than the original value of the required torque of the drive motor and less than the maximum limiting torque of the drive motor, the original value of the required torque of the drive motor is taken as the target torque of the drive motor.

[0125] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A torque distribution method for a hybrid power system, characterized in that, When a vehicle equipped with a hybrid system meets the activation conditions, the vehicle's current target engine torque, generator target torque, and drive motor target torque are obtained as follows: 1) Engine target torque: 1-1) Based on the current actual engine speed and the engine target torque economic control lookup table, determine the engine target torque threshold range corresponding to the current actual engine speed; 1-2) Determine the current engine target torque based on the current engine gear ratio, wheel end torque requirement, and the engine target torque threshold range obtained in step 1-1); 2) Generator target torque: 2-1) Calculate the maximum and minimum target torque limits of the generator based on the maximum charging power of the high-voltage battery, the maximum discharging power of the high-voltage battery, the power consumed by the accessories, and the actual speed of the generator; 2-2) Calculate the original value of the generator's required torque based on the wheel-end torque demand and the actual torque output from the engine to the wheel-end; 2-3) Determine the current generator target torque based on the maximum generator target torque limit, the minimum generator target torque limit, and the original generator required torque value; 3) Target torque of the drive motor: 3-1) Calculate the maximum limiting torque and minimum limiting torque of the drive motor based on the maximum discharge power of the high-voltage battery, the maximum charging power of the high-voltage battery, and the actual speed of the generator. 3-2) Calculate the original value of the required torque of the drive motor based on the required torque at the wheel end: When the required torque at the wheel end is ≥0, the original value of the required torque of the drive motor is calculated according to the following formula: ； In the formula, This is the original value of the torque required by the drive motor. For the required torque at the wheel end, This is the actual torque of the engine. This represents the actual torque of the generator. This refers to the transmission ratio between the engine and the generator. This is the actual torque of the clutch. The current engine gear ratio, This refers to the speed ratio corresponding to the current gear of the drive motor; When the required torque at the wheel end is less than 0, the original value of the required torque of the drive motor is calculated according to the following formula: ； In the formula, This is the original value of the torque required by the drive motor. For the required torque at the wheel end, This refers to the speed ratio corresponding to the current gear of the drive motor; 3-3) Determine the current target torque of the drive motor based on the maximum limit torque of the drive motor, the minimum limit torque of the drive motor, and the original value of the required torque of the drive motor.

2. The torque distribution method according to claim 1, characterized in that, The activation conditions are as follows: ① The car's key switch is in the ON position; ② The vehicle's powertrain system is in an active state; ③ The gear shift lever on the car's gear selector is in the D position; ④ The vehicle operates in parallel drive mode.

3. The torque distribution method according to claim 1, characterized in that, The engine target torque economic control lookup table includes several engine target torque threshold ranges corresponding to different engine speeds. This engine target torque economic control lookup table is obtained through whole vehicle testing based on vehicle fuel economy standards.

4. The torque distribution method according to claim 1, characterized in that, Based on the current engine gear ratio, wheel-end torque demand, and the engine target torque threshold range determined in step 1-1), the mathematical expression for the current engine target torque is as follows: ； In the formula, The current engine target torque, This represents the lower limit of the engine's target torque threshold range. For the required torque at the wheel end, This represents the upper limit of the engine's target torque threshold range. This represents the current engine gear ratio.

5. The torque distribution method according to claim 1, characterized in that, The mathematical expression for determining the current generator target torque based on the maximum generator target torque limit, the minimum generator target torque limit, and the original generator demand torque is as follows: ； In the formula, The target torque for the generator. This is the minimum target torque limit for the generator. The maximum value of the generator target torque limit. This represents the original value of the generator's required torque.

6. The torque distribution method according to claim 1 or 5, characterized in that, The specific method for calculating the original value of the generator's required torque based on the wheel-end torque demand and the actual torque output by the engine to the wheel-end is as follows: ① Calculate the actual torque output from the engine to the wheel ends using the following formula: The actual torque output by the engine to the wheels = actual engine torque × gear ratio corresponding to the current gear in the transmission ② Calculate the original value of the generator's required torque based on the wheel-end torque demand and the actual torque output from the engine to the wheel-end: If the actual torque output by the engine to the wheel ends is greater than the torque required at the wheel ends, then the original value of the generator's required torque is calculated according to the following formula: ； In the formula, This represents the original value of the generator's required torque. This is the actual torque of the engine. The gear ratio corresponding to the current gear in the transmission. For the required torque at the wheel end, This refers to the transmission ratio between the engine and the generator; If the actual torque output by the engine to the wheel end is less than or equal to the torque required by the wheel end, then the original value of the torque required by the generator is zero.

7. The torque distribution method according to claim 1 or 5, characterized in that, The maximum and minimum target torque limits for the generator are calculated using the following formulas: ； ； In the formula, The maximum value of the generator target torque limit. This is the minimum target torque limit for the generator. This represents the maximum discharge power of the high-voltage battery. This is the actual speed of the generator. Power consumed by the accessories This represents the maximum charging power of the high-voltage battery.

8. The torque distribution method according to claim 1, characterized in that, The maximum and minimum limiting torques of the drive motor are calculated according to the following formulas: ； ； In the formula, To limit the maximum torque of the drive motor, To drive the motor to the minimum limiting torque, This represents the maximum discharge power of the high-voltage battery. This represents the maximum charging power of the high-voltage battery. The generator's power output. Power consumed by the accessories To drive the actual speed of the motor, This refers to the speed ratio corresponding to the current gear of the drive motor.

9. The torque distribution method according to claim 1, characterized in that, The specific method for determining the current target torque of the drive motor based on the maximum limit torque, minimum limit torque, and original torque requirement of the drive motor is as follows: ； In the formula, To drive the target torque of the motor, To drive the motor to the minimum limiting torque, This is the original value of the torque required by the drive motor. This is the maximum limiting torque for the drive motor.

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