An electric drive transmission overall efficiency estimation method

Abstract

The application discloses a kind of electric drive transmission overall machine efficiency estimation methods, including according to function or effect, electric drive transmission is decomposed into multiple sub-systems;When sub-system is electric drive system, the efficiency of each component in electric drive system under preset working condition is determined;When sub-system is other sub-system except electric drive system, first determine the loss power of other sub-system under preset working condition, then the total efficiency of other sub-system under preset working condition is obtained;Based on the efficiency of each component in electric drive system under preset working condition and the total efficiency of other sub-system under preset working condition, the overall machine efficiency of electric drive transmission under preset working condition is determined.The application can evaluate overall machine efficiency before electric drive transmission development (before efficiency test), reduce the number of transmission efficiency test, shorten project development cycle, reduce project development cost.

Description

Technical Field

[0001] This invention belongs to the field of automotive transmissions, specifically relating to a method for estimating the overall efficiency of an electric drive transmission. Background Technology

[0002] As a crucial component of the transmission system, the transmission directly impacts a vehicle's power and fuel economy. Overall efficiency is a key technical indicator of the transmission assembly, reflecting not only its comprehensive performance but also its technological advancement. However, in the early stages of transmission development, without experimental support, only rough estimates of transmission efficiency can be made, leading to significant discrepancies.

[0003] Currently, the main way to obtain the overall efficiency of a transmission is through efficiency tests. This method cannot effectively evaluate the overall efficiency of the transmission in the early stages of a project, which seriously affects the development cycle of the transmission and is also not conducive to controlling the development cost of the transmission.

[0004] CN112380673A discloses a method and apparatus for optimizing transmission efficiency of a gearbox. It obtains the theoretical value of the gearbox's drag torque through expressions for the resistance torque of each component, and predicts and optimizes the gearbox efficiency after experimental calibration. However, it does not fully consider the components causing drag losses, making it unusable in the early stages of project design and failing to solve the efficiency assessment problem in the early design phase of the gearbox. Furthermore, it does not describe the method for obtaining the efficiency of an electric drive gearbox. Summary of the Invention

[0005] The purpose of this invention is to provide a method for estimating the overall efficiency of an electric drive transmission, so as to evaluate the overall efficiency in the early stage of electric drive transmission development (before efficiency testing), thereby reducing the number of transmission efficiency tests, shortening the project development cycle, and reducing project development costs.

[0006] The method for estimating the overall efficiency of an electric drive transmission as described in this invention includes:

[0007] Step 1: Based on function or purpose, the electric drive transmission is broken down into multiple subsystems.

[0008] Step 2: When the subsystem is an electric drive system, determine the efficiency of each component in the electric drive system under preset operating conditions; when the subsystem is another subsystem besides the electric drive system, first determine the power loss of the other subsystem under preset operating conditions, and then process it to obtain the total efficiency of the other subsystem under preset operating conditions.

[0009] Step 3: Based on the efficiency of each component in the electric drive system under preset operating conditions and the total efficiency of the other subsystems under preset operating conditions, determine the overall efficiency of the electric drive transmission under preset operating conditions.

[0010] The method for estimating the overall efficiency of electric drive transmissions described in this invention is mainly used for estimating the overall efficiency of electric drive transmissions with P13, P2, P3, and P4 configurations.

[0011] Preferably, if the electric drive transmission is a P13 configuration electric drive transmission, then the components in the electric drive system are: P1 motor (i.e., generator), P1 motor controller, P3 motor (i.e., drive motor) and P3 motor controller.

[0012] Using the formula: η ele_total_13 =A1×η 1M ×η 1M_control ×η 3M ×η 3M_control ×η other_P3 +B1×η 3M ×η 3M_control ×η other_P3 +C1×η other_P1 The overall efficiency η of the electric drive transmission with P13 configuration under preset operating conditions was calculated. ele_total_13 .

[0013] Where, η 1M η represents the efficiency of motor P1 under preset operating conditions. 1M_control η represents the efficiency of the P1 motor controller under preset operating conditions. 3M η represents the efficiency of motor P3 under preset operating conditions. 3M_control η represents the efficiency of the P3 motor controller under preset operating conditions. other_P3 η represents the total efficiency of the P3 path's subsystems excluding the electric drive system under preset operating conditions. other_P1 This represents the total efficiency of the subsystems other than the electric drive system in the P1 path under the preset operating conditions. A1, B1, and C1 are coefficients related to the operating mode of the electric drive transmission in the P13 configuration, and A1+B1+C1=1.

[0014] When the electric drive transmission of the P13 configuration operates in series mode, A1 = i, B1 = C1 = 0.

[0015] When the electric drive transmission of the P13 configuration is in pure electric mode, B1 = 1, A1 = C1 = 0.

[0016] When the electric drive transmission of the P13 configuration is in parallel mode, A1 = 0, B1 ≠ 0, C1 ≠ 0, B1 equals the preset first coefficient value, and C1 equals the preset second coefficient value.

[0017] When the P13 configuration electric drive transmission operates in engine direct drive mode, A1 = B1 = 0, C1 = 1.

[0018] When the electric drive transmission of the P13 configuration is in the hybrid mode I, A1≠0, B1≠0, C1≠0, A1 equals the preset third coefficient value, B1 equals the preset fourth coefficient value, and C1 equals the preset fifth coefficient value.

[0019] When the electric drive transmission of the P13 configuration is in the parallel-parallel mode II, A1≠0, B1≠0, C1=0, A1 equals the preset sixth coefficient value, and B1 equals the preset seventh coefficient value.

[0020] When the electric drive transmission of the P13 configuration is in the parallel-parallel mode III, A1≠0, B1=0, C1≠0, A1 equals the preset eighth coefficient value, and C1 equals the preset ninth coefficient value.

[0021] Preferably, the total efficiency η of the other subsystems along path P1, excluding the electric drive system, under preset operating conditions is obtained through processing. other_P1 The method is as follows:

[0022] First, use the formula: The total power loss P of the other subsystems along path P1, excluding the electric drive system, under the preset operating conditions was calculated. total.loss_P1 .

[0023] Reuse formula: The overall efficiency η of the P1 path other than the electric drive system under the preset operating conditions was calculated. other_P1 .

[0024] Where m represents the total number of subsystems other than the electric drive system in the P13 configuration electric drive transmission, Pl oss.k_P1 α represents the power loss of the k-th subsystem (excluding the electric drive system) in path P1 under preset operating conditions. k P represents the correlation coefficient between the power loss of the k-th subsystem (excluding the electric drive system) and the total power loss. input_P1 P represents the input power of the electric drive transmission path P1. input_P1 The values ​​are calculated based on the transmission input shaft speed and transmission input shaft torque under preset operating conditions in the P1 path.

[0025] Preferably, the total efficiency η of the P3 path subsystems other than the electric drive system under preset operating conditions is obtained through processing. other_P3 The method is as follows:

[0026] First, use the formula: The total power loss P of the P3 path other subsystems excluding the electric drive system under the preset operating conditions was calculated. total.loss_P3 .

[0027] Reuse formula: The overall efficiency η of the P3 path other subsystems excluding the electric drive system under the preset operating conditions was calculated. other_P3 .

[0028] Among them, P loss.k_P3 P represents the power loss of the k-th subsystem in path P3 (excluding the electric drive system) under preset operating conditions. input_P3 P represents the input power of the P3 path of the electric drive transmission. input_P3 The values ​​are calculated based on the transmission input shaft speed and transmission input shaft torque under preset operating conditions in the P3 path.

[0029] Preferably, if the electric drive transmission of the P13 configuration is a single-speed electric drive transmission, then the electric drive transmission of the P13 configuration is decomposed into 5 subsystems, namely: electric drive system, gear shaft system, hydraulic system, accessory system and clutch system, i.e., m=4.

[0030] P total.loss_P1 =α1×P loss·1_P1 +α2×P loss·2_P1 +α3×P loss·3_P1 +α4×P loss·4_P1 ;

[0031] P total.loss_P3 =α1×P loss·1_P3 +α2×P loss·2_P3 +α3×P loss·3_P3 +α4×P loss·4_P3 ;

[0032] Among them, P loss·1_P1 P represents the power loss of the gear shaft system along path P1 under the preset operating conditions. loss·2_P1 P represents the power loss of the hydraulic system along path P1 under preset operating conditions. loss·3_P1 P1 represents the power loss of the accessory system along path P1 under preset operating conditions. oss·4_P1 This represents the power loss of the clutch system in path P1 under preset operating conditions; P loss·1_P3 F represents the power loss of the gear shaft system along path P3 under the preset operating conditions. loss·2_P3 P represents the power loss of the hydraulic system along path P3 under preset operating conditions. loss·3_P3 P represents the power loss of the accessory system along path P3 under preset operating conditions. loss·4_P3 α1 represents the power loss of the clutch system in path P3 under preset operating conditions; α2 represents the correlation coefficient between the power loss of the preset gear shaft system and the total power loss; α3 represents the correlation coefficient between the power loss of the preset accessory system and the total power loss; and α4 represents the correlation coefficient between the power loss of the preset clutch system and the total power loss.

[0033] Preferably, if the electric drive transmission of the P13 configuration is a multi-speed electric drive transmission, then the electric drive transmission of the P13 configuration is decomposed into 6 subsystems, namely: electric drive system, gear shaft system, hydraulic system, accessory system, clutch system and shifting system; that is, m=5.

[0034] P total.loss_P1 =α1×P loss·1_P1 +α2×P loss·2_P1 +α3×P loss·3_P1 +α4×P loss·4_P1 +α5×P loss·5_P1 ;

[0035] P total.loss_P3 =α1×P loss·1_P3 +α2×P loss·2_P3 +α3×P loss·3_P3 +α4×P loss·4_P3 +α5×P loss·5_P3 ;

[0036] Among them, P loss·1_P1 P represents the power loss of the gear shaft system along path P1 under the preset operating conditions. loss·2_P1 P represents the power loss of the hydraulic system along path P1 under preset operating conditions. loss·3_P1 P represents the power loss of the accessory system along path P1 under preset operating conditions. loss·4_P1 P represents the power loss of the clutch system in path P1 under preset operating conditions. loss·5_P1 This represents the power loss of the shifting system along path P1 under preset operating conditions; P loss·1_P3 P represents the power loss of the gear shaft system along path P3 under the preset operating conditions. loss·2_P3 P represents the power loss of the hydraulic system along path P3 under preset operating conditions. loss·3_P3 F represents the power loss of the accessory system along path P3 under preset operating conditions. loss·4_P3 P represents the power loss of the clutch system in the P3 path under preset operating conditions. loss·5_P3 α1 represents the power loss of the shifting system in path P3 under preset operating conditions; α2 represents the correlation coefficient between the power loss of the preset gear shaft system and the total power loss; α3 represents the correlation coefficient between the power loss of the preset accessory system and the total power loss; α4 represents the correlation coefficient between the power loss of the preset clutch system and the total power loss; and α5 represents the correlation coefficient between the power loss of the preset shifting system and the total power loss.

[0037] Preferably, if the electric drive transmission is a P2 configuration electric drive transmission, then the components in the electric drive system are: a P2 motor (the P2 motor can be used as both a generator and a drive motor) and a P2 motor controller.

[0038] Using the formula: η ele_total_2 =B2×η 2M ×η 2M_control ×η other +C2×η other The overall efficiency η of the electric drive transmission with P2 configuration under preset operating conditions was calculated. ele_total_2 .

[0039] Where, η 2M η represents the efficiency of motor P2 under preset operating conditions. 2M_control η represents the efficiency of the P2 motor controller under preset operating conditions. other This represents the total efficiency of the subsystems other than the electric drive system under preset operating conditions. B2 and C2 are coefficients related to the operating mode of the electric drive transmission with P2 configuration, and B2+C2=1.

[0040] When the P2 configuration electric drive transmission is in pure electric mode, B2=1 and C2=0.

[0041] When the electric drive transmission of the P2 configuration is in parallel mode, B2≠0, C2≠0, B2 equals the preset tenth coefficient value, and C2 equals the preset eleventh coefficient value.

[0042] When the P2 configuration electric drive transmission operates in engine direct drive mode, B2=0 and C2=1.

[0043] Preferably, if the electric drive transmission is a P3 or P4 configuration electric drive transmission, then the components in the electric drive system are: a drive motor and a drive motor controller.

[0044] Using the formula: η ele_total_3_4 =η TM ×η TM_control ×η other The overall efficiency η of the electric drive transmission with P3 or P4 configuration under preset operating conditions is calculated. ele_total_3_4 .

[0045] Where, η TM η represents the efficiency of the drive motor under preset operating conditions. TM_control η represents the efficiency of the drive motor controller under preset operating conditions. other This indicates the overall efficiency of all subsystems other than the electric drive system under preset operating conditions.

[0046] Preferably, the total efficiency η of the subsystems other than the electric drive system under preset operating conditions is obtained through processing.other The method is as follows:

[0047] First, use the formula: The total power loss P of the subsystems other than the electric drive system under the preset operating conditions was calculated. total . loss .

[0048] Reuse formula: The overall efficiency η of the subsystems other than the electric drive system under the preset operating conditions was calculated. other .

[0049] Where v represents the total number of subsystems other than the electric drive system in the electric drive transmission, and P loss·j α represents the power loss of the j-th subsystem (excluding the electric drive system) under preset operating conditions. j P represents the correlation coefficient between the power loss of the j-th subsystem (excluding the electric drive system) and the total power loss. input P represents the input power of the electric drive transmission. input It is calculated based on the transmission input shaft speed and transmission input shaft torque under preset operating conditions.

[0050] Preferably, the P2 configuration electric drive transmission is decomposed into six subsystems: electric drive system, gear shaft system, hydraulic system, accessory system, clutch system, and shifting system, i.e., v = 5. Then P total.loss =α1×P loss·1 +α2×P loss·2 +α3×P loss·3 +α4×P loss·4 +α5×P loss·5 .

[0051] Preferably, the P3 or P4 configuration electric drive transmission is decomposed into four subsystems: an electric drive system, a gear and shaft system, a hydraulic system, and an accessory system, i.e., v = 3. Then P total.loss =α1×P loss·1 +α2×P loss·2 +α3×P loss·3 .

[0052] Among them, P loss·1 P represents the power loss of the gear shaft system under preset operating conditions. loss·2 P represents the power loss of the hydraulic system under preset operating conditions. loss·3 P represents the power loss of the accessory system under preset operating conditions. loss·4 P represents the power loss of the clutch system under preset operating conditions. loss·5α1 represents the power loss of the shifting system under preset operating conditions; α2 represents the correlation coefficient between the preset power loss of the gear shaft system and the total power loss; α3 represents the correlation coefficient between the preset power loss of the hydraulic system and the total power loss; α4 represents the correlation coefficient between the preset power loss of the accessory system and the total power loss; and α5 represents the correlation coefficient between the preset power loss of the shifting system and the total power loss.

[0053] The present invention has the following effects:

[0054] (1) By obtaining the power loss of other subsystems of the electric drive transmission besides the electric drive system, the total efficiency of other subsystems of the electric drive transmission besides the electric drive system is processed. Then, combined with the efficiency of each component in the electric drive system, the overall efficiency of the electric drive transmission is calculated. The power loss of other subsystems besides the electric drive system is obtained by simulation or test calculation, or by superimposing the power loss of the components. It considers the factors affecting the efficiency of the electric drive transmission very comprehensively, which improves the accuracy of the overall efficiency evaluation of the electric drive transmission.

[0055] (2) By using this method for estimating the overall efficiency of the electric drive transmission, we can not only accurately assess the overall efficiency of the electric drive transmission in the early stage of its development (i.e. before efficiency testing), but also predict in advance whether the efficiency improvement measures of each subsystem or component are effective, and provide specific efficiency change values ​​for the efficiency improvement scheme; subsequently, we can also conduct sensitivity analysis on the design parameters of each subsystem or component to find the key factors affecting its efficiency, and then optimize the efficiency of the subsystem or component through the optimization design of the key factors, and finally improve the overall efficiency.

[0056] (3) Using this method to estimate the overall efficiency of the electric drive transmission to evaluate the overall efficiency of the electric drive transmission not only reduces the number of transmission efficiency tests and shortens the project development cycle, but also reduces the project development cost. Attached Figure Description

[0057] Figure 1 This is a flowchart for estimating the overall efficiency of the electric drive transmission with configuration P13 in Example 1.

[0058] Figure 2 This is a flowchart for determining the power loss of other subsystems besides the electric drive system under preset operating conditions in Example 1.

[0059] Figure 3 This is a flowchart for determining the power loss of the gear shaft system under preset operating conditions in Example 1.

[0060] Figure 4 This is a flowchart for determining the power loss of the shifting system under preset operating conditions in Example 1.

[0061] Figure 5 This is a flowchart for estimating the overall efficiency of the electric drive transmission with configuration P13 in Example 2.

[0062] Figure 6 This is a flowchart for determining the power loss of other subsystems besides the electric drive system under preset operating conditions in Example 2.

[0063] Figure 7 This is a flowchart for estimating the overall efficiency of the electric drive transmission with the P2 configuration in Example 3.

[0064] Figure 8 This is a flowchart for determining the power loss of other subsystems besides the electric drive system under preset operating conditions in Example 3.

[0065] Figure 9 This is a flowchart for determining the power loss of the gear shaft system under preset operating conditions in Example 3.

[0066] Figure 10 This is a flowchart for determining the power loss of the clutch system under preset operating conditions in Example 3.

[0067] Figure 11 This is a flowchart for determining the power loss of the shifting system under preset operating conditions in Example 3.

[0068] Figure 12 This is a flowchart for estimating the overall efficiency of the electric drive transmission with the P3 configuration in Example 4.

[0069] Figure 13 This is a flowchart for determining the power loss of other subsystems besides the electric drive system under preset operating conditions in Example 4. Detailed Implementation

[0070] Example 1: The electric drive transmission in this example is a P13 configuration electric drive transmission, which is a multi-speed electric drive transmission. The preset operating conditions in this example refer to: P1 path, 1st gear transmission input shaft speed of 5000 rpm, transmission input shaft torque of 100 N·m, and lubricating oil temperature of 60°C; and P3 path, 1st gear transmission input shaft speed of 5500 rpm, transmission input shaft torque of 80 N·m, and lubricating oil temperature of 60°C. It should be noted that the preset operating conditions can also be other known gears, known transmission input shaft speeds, known transmission input shaft torques, and known lubricating oil temperatures for other P1 paths, and for other P3 paths.

[0071] like Figure 1 , Figure 2 As shown, the method for estimating the overall efficiency of the electric drive transmission in this embodiment includes:

[0072] The first step is to decompose the P13 configuration electric drive transmission into 6 subsystems based on its function or role. The 6 subsystems are: electric drive system, gear shaft system, hydraulic system, accessory system, clutch system, and shifting system.

[0073] The second step is to decompose the electric drive system into P1 motor (i.e., generator), P1 motor controller, P3 motor (i.e. drive motor) and P3 motor controller, and determine the efficiency of P1 motor, P1 motor controller, P3 motor and P3 motor controller under preset operating conditions.

[0074] Since the P1 motor, P1 motor controller, P3 motor, and P3 motor controller are all borrowed components with available efficiency test data in this embodiment, simulation is not required; the efficiency test data is used directly. Therefore, the efficiency η of the P1 motor under the preset operating conditions is obtained. 1M =95.8%, the efficiency η of the P1 motor controller under preset operating conditions 1M_control =98.72%, the efficiency η of the P3 motor under preset operating conditions 3M =95.85%, the efficiency η of the P3 motor controller under preset operating conditions 3M_control =97.96%.

[0075] If there is no efficiency test data for the motor and motor controller, then it is necessary to perform efficiency simulation of the motor and motor controller (which is existing technology) to obtain the efficiency of the motor and motor controller under preset operating conditions.

[0076] The third step is to determine the power loss of other subsystems besides the electric drive system under preset operating conditions. (See details for specific steps.) Figure 2 )include:

[0077] S11. Determine the power loss of the gear shaft system under preset operating conditions.

[0078] like Figure 3 As shown, the method for determining the power loss of the gear shaft system under preset operating conditions is as follows:

[0079] First, based on the geometric models of the gear shaft system and the electric drive transmission housing, a simulation model of the gear shaft system efficiency is built. The gear shaft system efficiency simulation model includes the electric drive transmission housing, shafts, gears, bearings, and lubricating oil within the gearbox.

[0080] Secondly, a simulation analysis of the gear shaft system efficiency under preset operating conditions was conducted to obtain the power loss of all meshing gears and all bearings under path P1, and the power loss of all meshing gears and all bearings under path P3. Two paths were considered in the analysis: one path from the output shaft of motor P3 (as the input shaft of the gear shaft system) to the differential output, defined as path P3; and the other path from the output shaft of motor P1 (as the input shaft of the gear shaft system) to the differential output, defined as path P1.

[0081] Then, based on the overall geometric model of the electric drive transmission, an oil churning analysis model of the gear shaft system was built, and a 3D oil churning simulation analysis was carried out under preset working conditions to obtain the oil churning loss power of the gear shaft system under path P1 and the oil churning loss power of the gear shaft system under path P3.

[0082] Finally, the power loss of all meshing gears and all bearings under path P1 (obtained through gear shaft system efficiency simulation analysis) and the oil churning power loss of the gear shaft system under path P1 (obtained through 3D oil churning simulation analysis) are added together to obtain the power loss P of the gear shaft system under the preset operating conditions under path P1. loss·1_P1 The power loss of all meshing gears and all bearings under path P3 (obtained through gear shaft system efficiency simulation analysis) and the power loss of the gear shaft system under path P3 (obtained through 3D oil churning simulation analysis) are added together to obtain the power loss P of the gear shaft system under the preset operating conditions under path P3. loss·1_P3 In this embodiment, P loss·1_P1 =1.87kW, P loss·1_P3 =1.12kW.

[0083] S12. Determine the power loss of the hydraulic system under preset operating conditions.

[0084] Since the mechanical oil pump used in the hydraulic system in this embodiment is a borrowed component, there is power loss test data available; therefore, simulation is not required, and the power loss test data is used directly; thus, the power loss of the mechanical oil pump in path P1 under the preset operating condition is 1.05kW, and the power loss of the mechanical oil pump in path P3 under the preset operating condition is 0.2kW.

[0085] The power loss of the mechanical oil pump in path P1 under the preset operating conditions is taken as the power loss P of the hydraulic system in path P1 under the preset operating conditions. loss.2_P1 The power loss of the mechanical oil pump in path P3 under the preset operating conditions is taken as the power loss P of the hydraulic system in path P3 under the preset operating conditions. loss·2_P3 In this embodiment, P loss·2_P1 =1.05kW, P loss·2_P3 =0.2kW.

[0086] If there is no test data on the power loss of the mechanical oil pump, it is necessary to perform a power loss simulation of the mechanical oil pump (which is existing technology) to obtain the power loss of the mechanical oil pump under preset operating conditions.

[0087] S13. Determine the power loss of the accessory system under preset operating conditions.

[0088] The method for determining the power loss of the accessory system under preset operating conditions is as follows:

[0089] First, use the formula: The total oil seal loss power P of path P1 was calculated. seal.loss_P1 Then, the total power loss P of the oil seal along path P1 is... seal.loss_P1 The power loss P of the auxiliary system as part of path P1 under the preset operating conditions loss·3_P1 Among them, ε x F is the coefficient related to the coefficient of friction for the x-th sealing ring. x R is the radial clamping force of the x-th sealing ring. x Let ω be the radius of the shaft sealed by the x-th sealing ring. x_P1 The rotational speed of the shaft sealed by the xth seal ring is obtained by converting the input shaft speed of the P1 path transmission (5000 rpm) under the preset operating condition into the corresponding speed ratio ω. x_P1 y represents the total number of seals along the P1 path in the P13 configuration electric drive transmission; ε x F x R x y and y are both known parameters. In this embodiment, P loss·3_P1 =P seal.loss_P1 =0.02kW.

[0090] First, use the formula: The total oil seal loss power P of path P3 was calculated. seal.loss_P3 Then, the total power loss P of the oil seal in path P3 is... seal.loss_P3 The power loss P of the auxiliary system as part of the P3 path under the preset operating conditions loss·3_P3 Among them, ε r F is the coefficient related to the coefficient of friction for the r-th sealing ring. r R is the radial clamping force of the r-th sealing ring. r Let ω be the radius of the shaft sealed by the r-th sealing ring. r_P3 The rotational speed of the shaft sealed by the r-th seal ring is obtained by converting the input shaft speed of the P3 path transmission (5500 rpm) under the preset operating conditions into the corresponding speed ratio ω. r_P3 u is the total number of seals along the P3 path in the P13 configuration electric drive transmission; ε r F r R r Both and u are known parameters. In this embodiment, Ploss·3_P3 =P seal.loss_P3 =0.01kW.

[0091] S14. Determine the power loss of the clutch system under preset operating conditions.

[0092] In this embodiment, the clutch system of the P13 configuration electric drive transmission only has inter-clutch disc dragging, without clutch housing churning.

[0093] Since the clutch in this embodiment has individual test data, the inter-clutch drag loss power under the preset operating conditions is directly read based on the test data. At the same time, since the clutch is engaged in the P1 path, the inter-clutch drag loss power in the P1 path under the preset operating conditions is 0kW; the inter-clutch drag loss power in the P3 path under the preset operating conditions is 0.11kW.

[0094] The inter-clutch drag loss power of the P1 path under the preset operating condition is taken as the loss power P of the clutch system under the preset operating condition. loss·4_P1 The inter-clutch plate drag loss power under the preset operating condition P3 path is taken as the loss power P of the clutch system under the preset operating condition. loss·4_P3 In this embodiment, P loss·4_P1 =0kW, P loss·4_P3 =0.11kW.

[0095] If there is no individual clutch test data, it is necessary to perform a simulation analysis of the inter-clutch drag loss under preset operating conditions (which is existing technology) to obtain the inter-clutch drag loss power under preset operating conditions.

[0096] S15. Determine the power loss of the shifting system under preset operating conditions.

[0097] like Figure 4 As shown, the method for determining the power loss of the shifting system under preset operating conditions is as follows:

[0098] First, based on the geometric model of the i-th synchronizer, a drag loss simulation model of the i-th synchronizer is built. This drag loss simulation model considers the components of the synchronizer friction pair (gear ring, idler gear, friction cone), the roughness and friction coefficient of the friction cone contact surface, the speed difference between the friction cones, the lubricating oil flow rate and performance parameters, and the synchronizer operating temperature. Here, i takes any integer from 1 to n, and n is the total number of synchronizers in the shifting system (n is a known parameter). In this embodiment, n = 1, meaning that the electric drive transmission with configuration P13 in this embodiment has only one synchronizer, and this synchronizer has friction cones at both ends.

[0099] Secondly, based on the drag loss simulation model of the i-th synchronizer, simulation analysis and calculation are performed to obtain the drag loss power P of the i-th synchronizer on path P1. sync·loss_i_P1 The drag loss power P of the i-th synchronizer on path P3 sync·loss_i_P3 Specifically: In gear 1, the right friction cone of the i-th synchronizer is engaged, and the left friction cone is disengaged. First, fix the right end of the geometric model of the i-th synchronizer, and load the left end with the rotational speed difference n of the left friction cone of the i-th synchronizer along path P1. i_1_P1 Simulation analysis was performed to obtain the drag loss torque T at the left end of the i-th synchronizer on path P1. sync·loss_i_1_P1 The drag loss torque T at the right end of the i-th synchronizer in path P1 is... sync·loss_i_2_P1 =0 (because the right friction cone is in the engaged state, its drag loss torque is equal to 0). Then, fix the right end of the synchronizer's geometric model and load the left end with the speed difference n of the left friction cone of the i-th synchronizer along path P3. i_1_P3 Simulation analysis was performed to obtain the drag loss torque T at the left end of the i-th synchronizer on path P3. sync·loss_i_1_P3 The drag loss torque T at the right end of the i-th synchronizer in path P3 is... sync·loss_i_2_P3 =0 (because the right friction cone is in the engaged state, therefore its drag loss torque is equal to 0). Then, using the formula: P sync·loss_i_1_P1 =T sync·loss_i_1_P1 ×n i_1_P1 / 9549, P sync·loss_i_1_P3 =T sync·loss_i_1_P3 ×n i_1_P3 / 9549, calculate the drag loss power P at the left end of the i-th synchronizer in path P1. sync·loss_i_1_P1 The power loss P at the left end of the i-th synchronizer in path P3 is due to drag. sync·loss_i_1_P3 Additionally, the drag loss P at the right end of the i-th synchronizer in path P1 is... sync·loss_i_2_P1 =0, the drag loss power P at the right end of the i-th synchronizer in path P3 is 0. sync·loss_i_2_P3 =0. Finally, using the formula: P sync·loss_i_P1 =P sync·loss_i_1_P1 +P sync·loss_i_2_P1 The drag loss power P of the i-th synchronizer on path P1 is calculated. sync·loss_i_P1 Using the formula: P sync·loss_i_P3 =P sync·loss_i_1_P3 +P sync·loss_i_2_P3 The drag loss power P of the i-th synchronizer in path P3 is calculated. sync·loss_i_P3 Wherein, the rotational speed difference n of the left friction cone of the i-th synchronizer in path P1 is... i_1_P1 The speed difference n of the left friction cone of the i-th synchronizer in path P3 is obtained by converting the input shaft speed (5000 rpm) of the transmission under preset operating conditions and the corresponding gear and shaft speed ratios (this is existing technology).i_1_P3 The speed ratio of the input shaft of the P3 path transmission under preset working conditions (5500 rpm) is calculated by converting the corresponding gear and shaft speed ratio (which is existing technology).

[0100] Then, using the formula: The total power loss P of the P1 path synchronizer was calculated. sync·loss_P1 Using the formula: The total power loss P of the P3 path synchronizer was calculated. sync·loss_P3 .

[0101] Finally, the total power loss P of the P1 path synchronizer is... sync·loss_P1 The power loss P of the shifting system as P1 path under preset operating conditions loss·5_P1 The total power loss P of the P3 path synchronizer sync·loss_P3 The power loss P of the shifting system as the P3 path under preset operating conditions loss·5_P3 According to calculations, in this embodiment, P loss·5_P1 =0.05kW, P loss·5_P3 =0.03kW.

[0102] The fourth step is to process the power loss of other subsystems besides the electric drive system under the preset operating conditions to obtain the total efficiency of other subsystems besides the electric drive system under the preset operating conditions.

[0103] Based on the above analysis, under the preset operating conditions, P loss·1_P1 =1.87kW, P loss·1_P3 =1.12kW, P loss·2_P1 =1.05kW, P loss·2_P3 =0.2kW, P loss·3_P1 =0.02kW, P loss·3_P3 =0.01kW, P loss·4_P1 =0kW, P loss·4_P3 =0.11kW, P loss·5_P1 =0.05kW, P loss·5_P3=0.03kW. In this embodiment, the correlation coefficient between the power loss of the preset gear shaft system and the total power loss (i.e., the correlation coefficient between the power loss of the first subsystem and the total power loss) α1 = 1, the correlation coefficient between the power loss of the preset hydraulic system and the total power loss (i.e., the correlation coefficient between the power loss of the second subsystem and the total power loss) α2 = 1, the correlation coefficient between the power loss of the preset accessory system and the total power loss (i.e., the correlation coefficient between the power loss of the third subsystem and the total power loss) α3 = 1, the correlation coefficient between the power loss of the preset clutch system and the total power loss (i.e., the correlation coefficient between the power loss of the fourth subsystem and the total power loss) α4 = 1, and the correlation coefficient between the power loss of the preset shifting system and the total power loss (i.e., the correlation coefficient between the power loss of the fifth subsystem and the total power loss) α5 = 1.

[0104] The specific handling method is as follows:

[0105] First, use the formula: The total power loss P of the other subsystems along path P1, excluding the electric drive system, under the preset operating conditions was calculated. total.loss_P1 In this embodiment, P total.loss_P1 =1.87+1.05+0.02+0+0.05=2.99kW.

[0106] Reuse formula: The overall efficiency η of the P1 path other than the electric drive system under the preset operating conditions was calculated. other_P1 Among them, P input_P1 P represents the input power of the electric drive transmission path P1. input_P1 The values ​​are calculated based on the input shaft speed (5000 rpm) and input shaft torque (100 N·m) of the transmission in path P1 under preset operating conditions. In this embodiment, P... input_P1 =5000*100 / 9549=52.36kW

[0107] First, use the formula: The total power loss P of the P3 path other subsystems excluding the electric drive system under the preset operating conditions was calculated. total.loss_P3 In this embodiment, P total.loss_P3 =1.12+0.2+0.01+0.11+0.03=1.47kW.

[0108] Reuse formula: The overall efficiency η of the P3 path other subsystems excluding the electric drive system under the preset operating conditions was calculated. other_P3 .

[0109] Among them, P input_P3 P represents the input power of the P3 path of the electric drive transmission. input_P3 The values ​​are calculated based on the input shaft speed (5500 rpm) and input shaft torque (80 N·m) of the transmission in the P3 path under preset operating conditions. In this embodiment, P... input_P3 =5500*80 / 9549=46.08kW

[0110] Step 5: Based on the efficiency of each component in the electric drive system under preset operating conditions and the total efficiency of other subsystems under preset operating conditions, determine the overall efficiency of the electric drive transmission of the P13 configuration under preset operating conditions.

[0111] Using the formula: η ele_total_13 =A1×η 1M ×η 1M_control ×η 3M ×η 3M_control ×η other_P3 +B1×η 3M ×η 3M_control ×η other_P3 +C1×η other_P1 The overall efficiency η of the electric drive transmission with P13 configuration under preset operating conditions was calculated. ele_total_13 A1, B1, and C1 are coefficients related to the operating mode of the electric drive transmission in the P13 configuration. i +B1+C1=1.

[0112] When the electric drive transmission of the P13 configuration operates in series mode (P1 motor generates electricity), A1 = 1, B1 = C1 = 0. In series mode, η ele_total_13 =1×η 1M ×η 1M_control ×η 3M ×η 3M_control ×η omer_P3 = 1 × 95.8% × 98.72% × 95.85% × 97.96% × 96.81% = 85.97%. That is, in series mode, the overall efficiency of the P13 configuration electric drive transmission under the preset operating conditions is 85.97%.

[0113] When the electric drive transmission of the P13 configuration operates in pure electric mode (P1 motor does not generate electricity), B1 = 1, A1 = C1 = 0. In pure electric mode, η ele_total_13 =1×η 3M ×η 3M_control ×η omer_P3 = 1 × 95.85% × 97.96% × 96.81% = 90.9%. That is, in pure electric mode, the overall efficiency of the P13 configuration electric drive transmission under the preset operating conditions is 90.9%.

[0114] When the electric drive transmission of the P13 configuration operates in parallel mode (P1 motor does not generate electricity), A1 = 0, B1 = 0.6, C1 = 0.4. In parallel mode, η ele_total_13 =0.6×η 3M ×η 3M_control ×η omer_P3 +0.4×η other_P1 = 0.6 × 95.85% × 97.96% × 96.81% + 0.4 × 94.29% = 92.26%. That is, in parallel mode, the overall efficiency of the P13 configuration electric drive transmission under the preset operating conditions is 92.26%.

[0115] When the P13 configuration electric drive transmission operates in engine direct drive mode, A1 = B1 = 0, C1 = 1.

[0116] In engine direct drive mode, η ele_total_13 =1×η other-P1 =1 × 94.29% = 94.29%. In engine direct drive mode, the overall efficiency of the P13 configuration electric drive transmission under preset operating conditions is 94.29%.

[0117] When the electric drive transmission of the P13 configuration is in the parallel-parallel mode I, A1 = 0.4, B1 = 0.3, and C1 = 0.3.

[0118] In hybrid mode I, η ele_total_13 =0.4×η 1M ×η 1M_control ×η 3M ×η 3M_control ×η other_P3 +0.3×η 3M ×η 3M_control ×η other_P3 +0.3×η other_P1 = 0.4 × 95.8% × 98.72% × 95.85% × 97.96% × 96.81% + 0.3 × 95.85% × 97.96% × 96.81% + 0.3 × 94.29% = 89.94%. That is, under hybrid mode I, the overall efficiency of the P13 configuration electric drive transmission under the preset operating conditions is 89.94%.

[0119] When the electric drive transmission of the P13 configuration is in the parallel-parallel mode II, A1 = 0.6, B1 = 0.4, and C1 = 0.

[0120] In hybrid mode II, η ele_tota1_13 =0.6×η 1M ×η 1M_control ×η 3M ×η 3M_control ×η omer_P3+0.4×η 3M ×η 3M_control ×η otherP3 = 0.6 × 95.8% × 98.72% × 95.85% × 97.96% × 96.81% + 0.4 × 95.85% × 97.96% × 96.81% = 87.94%. That is, under the hybrid mode II, the overall efficiency of the P13 configuration electric drive transmission under the preset operating conditions is 87.94%.

[0121] When the electric drive transmission of the P13 configuration is operating in the parallel-parallel mode III, A1 = 0.65, B1 = 0, and C1 = 0.35.

[0122] In hybrid mode III, η ele_total_13 =0.65×η 1M ×η 1M_control ×η 3M ×η 3M_control ×η other_P3 +0.35×η omer_P1 = 0.65 × 95.8% × 98.72% × 95.85% × 97.96% × 96.81% + 0.35 × 94.29% = 88.88%. That is, under the hybrid mode III, the overall efficiency of the electric drive transmission of the P13 configuration under the preset operating conditions is 88.88%.

[0123] Example 2: The electric drive transmission in this example is a P13 configuration electric drive transmission, which is a single-speed electric drive transmission (without a shift system). The preset operating conditions in this example refer to the following: for the P1 path, the transmission input shaft speed is 5000 rpm, the transmission input shaft torque is 100 N·m, and the lubricating oil temperature is 60°C; for the P3 path, the transmission input shaft speed is 5500 rpm, the transmission input shaft torque is 80 N·m, and the lubricating oil temperature is 60°C. It should be noted that the preset operating conditions can also be other known transmission input shaft speeds, torques, and lubricating oil temperatures for the P1 path and the P3 path.

[0124] like Figure 5 , Figure 6 As shown, the method for estimating the overall efficiency of the electric drive transmission in this embodiment includes:

[0125] The first step is to decompose the P13 configuration electric drive transmission into five subsystems based on its function or role. The five subsystems are: electric drive system, gear shaft system, hydraulic system, accessory system, and clutch system.

[0126] The second step is to decompose the electric drive system into P1 motor (i.e., generator), P1 motor controller, P3 motor (i.e. drive motor) and P3 motor controller, and determine the efficiency of P1 motor, P1 motor controller, P3 motor and P3 motor controller under preset operating conditions.

[0127] Since the P1 motor, P1 motor controller, P3 motor, and P3 motor controller are all borrowed components with available efficiency test data in this embodiment, simulation is not required; the efficiency test data is used directly. Therefore, the efficiency η of the P1 motor under the preset operating conditions is obtained. 1M =95.8%, the efficiency η of the P1 motor controller under preset operating conditions 1M_control =98.72%, the efficiency η of the P3 motor under preset operating conditions 3M =95.85%, the efficiency η of the P3 motor controller under preset operating conditions 3M_control =97.96%.

[0128] If there is no efficiency test data for the motor and motor controller, then it is necessary to perform efficiency simulation of the motor and motor controller (which is existing technology) to obtain the efficiency of the motor and motor controller under preset operating conditions.

[0129] The third step is to determine the power loss of other subsystems besides the electric drive system under preset operating conditions. (See details for specific steps.) Figure 6 )include:

[0130] S21. Determine the power loss of the gear shaft system under preset operating conditions. The method for determining this power loss is the same as in Example 1. In this example, P... loss.1_P1 =1.87kW, P loss.1_P3 =1.12kW.

[0131] S22. Determine the power loss of the hydraulic system under preset operating conditions.

[0132] Since the mechanical oil pump used in the hydraulic system in this embodiment is a borrowed component, there is power loss test data available; therefore, simulation is not required, and the power loss test data is used directly; thus, the power loss of the mechanical oil pump in path P1 under the preset operating condition is 1.05kW, and the power loss of the mechanical oil pump in path P3 under the preset operating condition is 0.2kW.

[0133] The power loss of the mechanical oil pump in path P1 under the preset operating conditions is taken as the power loss P of the hydraulic system in path P1 under the preset operating conditions. loss.2_P1 The power loss of the mechanical oil pump in path P3 under the preset operating conditions is taken as the power loss P of the hydraulic system in path P3 under the preset operating conditions. loss.2_P3 In this embodiment, P loss.2_P1 =1.05kW, P loss.2_P3 =0.2kW.

[0134] If there is no test data on the power loss of the mechanical oil pump, it is necessary to perform a power loss simulation of the mechanical oil pump (which is existing technology) to obtain the power loss of the mechanical oil pump under preset operating conditions.

[0135] S23. Determine the power loss of the accessory system under preset operating conditions. The method for determining this power loss is the same as in Example 1. In this example, P... loss.3_P1 =P seal.loss_P1 =0.02kW, P loss.3_P3 =P seal.1oss_P3 =0.01kW.

[0136] S24. Determine the power loss of the clutch system under preset operating conditions.

[0137] In this embodiment, the clutch system of the P13 configuration electric drive transmission only has inter-clutch disc dragging, without clutch housing churning.

[0138] Since the clutch in this embodiment has individual test data, the inter-clutch drag loss power under the preset operating conditions is directly read based on the test data. At the same time, since the clutch is engaged in the P1 path, the inter-clutch drag loss power in the P1 path under the preset operating conditions is 0kW; the inter-clutch drag loss power in the P3 path under the preset operating conditions is 0.11kW.

[0139] The inter-clutch drag loss power of the P1 path under the preset operating condition is taken as the loss power P of the clutch system under the preset operating condition. loss.4_P1 The inter-clutch plate drag loss power under the preset operating condition P3 path is taken as the loss power P of the clutch system under the preset operating condition. loss.4_P3 In this embodiment, P loss.4_P1 =0kW, P loss.4_P3 =0.11kW.

[0140] If there is no individual clutch test data, it is necessary to perform a simulation analysis of the inter-clutch drag loss under preset operating conditions (which is existing technology) to obtain the inter-clutch drag loss power under preset operating conditions.

[0141] The fourth step is to process the power loss of other subsystems besides the electric drive system under the preset operating conditions to obtain the total efficiency of other subsystems besides the electric drive system under the preset operating conditions.

[0142] Based on the above analysis, under the preset operating conditions, P loss.1_P1 =1.87kW, P loss.1_p3 =1.12kW, P loss.2_P1 =1.05kW, P loss.2_P3 =0.2kW, P loss.3_P1 =0.02kW, Ploss.3_P3 =0.01kW, P loss·4_P1 =0kW, P loss.4_P3 =0.11kW. In this embodiment, α1 = α2 = α3 = α4 = 1.

[0143] The specific handling method is as follows:

[0144] First, use the formula: The total power loss P of the other subsystems along path P1, excluding the electric drive system, under the preset operating conditions was calculated. total.1oss_P1 In this embodiment, P total.1oss_P1 =1.87+1.05+0.02+0=2.94kW.

[0145] Reuse formula: The overall efficiency η of the P1 path other than the electric drive system under the preset operating conditions was calculated. other_P1 Among them, P input_p1 P represents the input power of the electric drive transmission path P1. input_P1 The values ​​are calculated based on the input shaft speed (5000 rpm) and input shaft torque (100 N·m) of the transmission in path P1 under preset operating conditions. In this embodiment, P... input_P1 =5000*100 / 9549=52.36kW

[0146] First, use the formula: The total power loss P of the P3 path other subsystems excluding the electric drive system under the preset operating conditions was calculated. total.loss_P3 In this embodiment, P total.1oss_P3 =1.12+0.2+0.01+0.11=1.44kW.

[0147] Reuse formula: The overall efficiency η of the P3 path other subsystems excluding the electric drive system under the preset operating conditions was calculated. other_P3 .

[0148] Among them, P input_P3 P represents the input power of the P3 path of the electric drive transmission. input_P3 The values ​​are calculated based on the input shaft speed (5500 rpm) and input shaft torque (80 N·m) of the transmission in the P3 path under preset operating conditions. In this embodiment, P... input_P3 =5500*80 / 9549=46.08kW

[0149] Step 5: Based on the efficiency of each component in the electric drive system under preset operating conditions and the total efficiency of other subsystems under preset operating conditions, determine the overall efficiency of the electric drive transmission of the P13 configuration under preset operating conditions.

[0150] Using the formula: η ele_total_13 =A1×η 1M ×η 1M_control ×η 3M ×η 3M_control ×η other_P3 +B1×η 3M ×η 3M_control ×η other_P3 +C1×η other_P1 The overall efficiency η of the electric drive transmission with P13 configuration under preset operating conditions was calculated. ele_total_13 A1, B1, and C1 are coefficients related to the operating mode of the electric drive transmission in the P13 configuration, and A1+B1+C1=1.

[0151] When the electric drive transmission of the P13 configuration operates in series mode (P1 motor generates electricity), A1 = 1, B1 = C1 = 0. In series mode, η ele_total_13 =1×η 1M ×η 1M_control ×η 3M ×η 3M_control ×η other_P3 = 1 × 95.8% × 98.72% × 95.85% × 97.96% × 96.87% = 86.02%. That is, in series mode, the overall efficiency of the P13 configuration electric drive transmission under the preset operating conditions is 86.02%.

[0152] When the electric drive transmission of the P13 configuration operates in pure electric mode (P1 motor does not generate electricity), B1 = 1, A1 = C1 = 0. In pure electric mode, η ele_total_13 =1×η 3M ×η 3M_control ×η other_P3 = 1 × 95.85% × 97.96% × 96.87% = 90.96%. That is, in pure electric mode, the overall efficiency of the P13 configuration electric drive transmission under the preset operating conditions is 90.96%.

[0153] When the electric drive transmission of the P13 configuration operates in parallel mode (P1 motor does not generate electricity), A1 = 0, B1 = 0.6, C1 = 0.4. In parallel mode, η ele_t0tal_13 =0.6×η 3M ×η 3M_control ×η other_P3 +0.4×η other_P1= 0.6 × 95.85% × 97.96% × 96.87% + 0.4 × 94.39% = 92.33%. That is, in parallel mode, the overall efficiency of the P13 configuration electric drive transmission under the preset operating conditions is 92.33%.

[0154] When the P13 configuration electric drive transmission operates in engine direct drive mode, A1 = B1 = 0, C1 = 1.

[0155] In engine direct drive mode, η ele_total_13 =1×η other-P1 =1 × 94.39% = 94.39%. In engine direct drive mode, the overall efficiency of the P13 configuration electric drive transmission under preset operating conditions is 94.39%.

[0156] When the electric drive transmission of the P13 configuration is in the parallel-parallel mode I, A1 = 0.4, B1 = 0.3, and C1 = 0.3.

[0157] In hybrid mode I, η ele_total_13 =0.4×η 1M ×η 1M_control ×η 3M ×η 3M_control ×η other_P 3+0.3×η 3M ×η 3M_control ×η other_P3 +0.3×η other_P1 = 0.4 × 95.8% × 98.72% × 95.85% × 97.96% × 96.87% + 0.3 × 95.85% × 97.96% × 96.87% + 0.3 × 94.39% = 90.01%. That is, under hybrid mode I, the overall efficiency of the P13 configuration electric drive transmission under the preset operating conditions is 90.01%.

[0158] When the electric drive transmission of the P13 configuration is in the parallel-parallel mode II, A1 = 0.6, B1 = 0.4, and C1 = 0.

[0159] In hybrid mode II, η ele_total_13 =0.6×η 1M ×η 1M_control ×η 3M ×η 3M_control ×η other_P3 +0.4×η 3M ×η 3M_control ×η otherP3= 0.6 × 95.8% × 98.72% × 95.85% × 97.96% × 96.87% + 0.4 × 95.85% × 97.96% × 96.87% = 87.99%. That is, under the hybrid mode II, the overall efficiency of the P13 configuration electric drive transmission under the preset operating conditions is 87.99%.

[0160] When the electric drive transmission of the P13 configuration is in the parallel-parallel mode III, A1 = 0.65, B1 = 0, and C1 = 0.35.

[0161] In hybrid mode III, η ele_total_13 =0.65×η 1M ×η 1M_control ×η 3M ×η 3M_control ×η other_P3 +0.35×η other_P1 = 0.65 × 95.8% × 98.72% × 95.85% × 97.96% × 96.87% + 0.35 × 94.39% = 88.95%. That is, under the hybrid mode III, the overall efficiency of the electric drive transmission of the P13 configuration under the preset operating conditions is 88.95%.

[0162] Example 3: The electric drive transmission in this example is a P2 configuration electric drive transmission. The preset operating condition in this example refers to the condition where the gear is 1st gear, the transmission input shaft speed is 2500 rpm, the transmission input shaft torque is 60 N·m, and the lubricating oil temperature is 60°C. It should be noted that the preset operating condition can also be other known gears, known transmission input shaft speeds, known transmission input shaft torques, and known lubricating oil temperatures.

[0163] like Figure 7 , Figure 8 As shown, the method for estimating the overall efficiency of the electric drive transmission in this embodiment includes:

[0164] The first step is to break down the P2 configuration electric drive transmission into six subsystems based on their function or role. These six subsystems are: electric drive system, gear and shaft system, hydraulic system, accessory system, clutch system, and shifting system.

[0165] The second step is to decompose the electric drive system into P2 motor (which can be used as a generator or a drive motor) and P2 motor controller, and determine the efficiency of P2 motor and P2 motor controller under preset operating conditions.

[0166] Since both the P2 motor and its controller are borrowed components in this embodiment, and efficiency test data is available, simulation is not required; the efficiency test data is used directly. Therefore, the efficiency η of the P2 motor under the preset operating conditions is obtained. 2M=96.35%, the efficiency η of the P2 motor controller under preset operating conditions 2M_control =98.05%.

[0167] If there is no efficiency test data for the motor and motor controller, then it is necessary to perform efficiency simulation of the motor and motor controller (which is existing technology) to obtain the efficiency of the motor and motor controller under preset operating conditions.

[0168] The third step is to determine the power loss of other subsystems besides the electric drive system under preset operating conditions. (See details for specific steps.) Figure 8 )include:

[0169] S31. Determine the power loss of the gear shaft system under preset operating conditions.

[0170] like Figure 9 As shown, the method for determining the power loss of the gear shaft system under preset operating conditions is as follows:

[0171] First, a gear shaft system efficiency simulation model is built based on the geometric models of the gear shaft system and the electric drive transmission housing. This model considers the geometric dimensions and materials of the electric drive transmission housing, all shafts and gears, the structural and performance parameters of all bearings, the performance parameters of the lubricating oil, the temperature of the lubricating oil, and the oil immersion depth parameters of the shaft system. The gear shaft system efficiency simulation model includes: the transmission housing, shafts, gears, bearings, and the lubricating oil within the gearbox. The input shaft of the gear shaft system efficiency simulation model is defined with a preset operating condition of 2500 rpm for the transmission input shaft and 60 N·m for the transmission input shaft. Power output is defined in the differential housing or output shaft.

[0172] Secondly, a gear shaft system efficiency simulation analysis was conducted under preset working conditions to obtain the power loss of all meshing gears and the power loss of all bearings.

[0173] Then, based on the overall geometric model of the electric drive transmission, an oil churning analysis model of the gear shaft system was built, and 3D oil churning simulation analysis under preset working conditions was carried out to obtain the oil churning loss power of the gear shaft system.

[0174] Finally, the power loss of all meshing gears (obtained through gear shaft system efficiency simulation analysis), the power loss of all bearings, and the oil churning power loss of the gear shaft system (obtained through 3D oil churning simulation analysis) are added together to obtain the power loss P of the gear shaft system under the preset operating conditions. loss.1 (That is, the power loss of the first subsystem under the preset operating conditions). In this embodiment, the power loss P of the gear shaft system under the preset operating conditions. loss.1 =0.57kW. Because the power loss of the gear shaft system obtained through 3D oil churning simulation analysis is more accurate, the power loss of the gear shaft system under the preset working conditions is also more accurate.

[0175] S32. Determine the power loss of the hydraulic system under preset operating conditions.

[0176] Since the P2 configuration electric drive transmission uses an electronic oil pump, the power loss of the electronic oil pump is 0kW in the efficiency simulation. Therefore, the power loss of the hydraulic system under the preset operating conditions (i.e., the power loss of the second subsystem under the preset operating conditions) P loss.2 =0kW.

[0177] S33. Determine the power loss of the accessory system under preset operating conditions.

[0178] The method for determining the power loss of the accessory system under preset operating conditions is as follows:

[0179] First, use the formula: The total power loss P of the oil seal was calculated. seal.loss Among them, ε t F is the coefficient related to the coefficient of friction for the t-th sealing ring. t R is the radial clamping force of the t-th sealing ring. t Let ω be the radius of the shaft sealed by the t-th sealing ring. t The rotational speed of the shaft sealed by the t-th seal ring is obtained by converting the input shaft speed of the transmission under the preset working condition of 2500 rpm into the corresponding speed ratio ω. t w represents the total number of seals in the electric drive transmission; ε t F t R t Both and w are known parameters.

[0180] Then calculate the total power loss P of the oil seal. seal.loss The power loss P of the accessory system under preset operating conditions loss.3 (i.e., the power loss of the third subsystem under preset operating conditions). In this embodiment, P loss.3 =0.006kW.

[0181] S34. Determine the power loss of the clutch system under preset operating conditions.

[0182] In this embodiment, the power loss of the clutch system includes the power loss due to drag between clutch plates and the power loss due to oil churning in the clutch housing.

[0183] like Figure 10 As shown, the method for determining the power loss of the clutch system under preset operating conditions is as follows:

[0184] First, the clutch system is broken down into the clutch housing, steel plates, friction plates, and clutch bearings.

[0185] Secondly, based on the specific structure of the steel plates and friction plates, the flow rate and performance parameters of the lubricating oil, the clutch operating temperature, and the speed difference between the steel plates and friction plates, a simulation model of clutch plate drag loss is built. Simulation analysis of clutch plate drag loss under preset working conditions is conducted to obtain the clutch plate drag loss torque T under different modes when connecting even-numbered gears. loss.4_1_1 The torque T lost due to drag between the clutch plates connected to the engine and the clutch plate. loss.4_1_2 In this embodiment, in pure electric mode, the clutches connecting even-numbered gears and the clutches connecting to the engine are disengaged, and both exhibit drag. Therefore, T loss.4_1_1 =0.764 Nm, T loss.4_1_2 =0.53Nm; In parallel mode or engine direct drive mode, only the even-numbered gears are clutch disengaged, resulting in drag, therefore T loss.4_1_1 =0.764 Nm, T loss.4_1_2 =0N.m.

[0186] Next, calculate the inter-clutch drag loss power P under different modes. loss.4_1 Specifically: First, use the formula: P loss.4_1_1 =T loss.4_1_1 ×ω / 9549, the inter-clutch drag loss power P in different modes of connecting even-numbered gears is calculated. loss.4_1_1 ; Reusing the formula: P loss.4_1_2 =T loss.4_1_2 ×ω / 9549, the inter-clutch drag loss power P of the engine connection under different modes is calculated. loss.4_1_2 Finally, using the formula: P loss.4_1 =P loss.4_1_1 +P loss.4_1_2 The inter-clutch drag loss power P under different modes was calculated. loss.4_1 Where ω represents the clutch input shaft speed, ω is equal to the transmission input shaft speed under preset operating conditions, and in this embodiment, ω = 2500 rpm. Therefore, the inter-clutch drag loss power P in pure electric mode is calculated. loss.4_1 =0.2 + 0.139 = 0.339kW, the inter-clutch drag power P in parallel mode or engine direct drive mode is calculated. loss.4_1 =0.2+0=0.2kW.

[0187] Then, based on the clutch housing structure, rotational speed, outer envelope of the clutch mounting cavity, lubricating oil performance parameters, clutch bearings, and oil immersion depth of the clutch housing, a clutch housing churning analysis model was built. A simulation analysis of the clutch housing churning power loss under preset operating conditions was conducted to obtain the clutch housing churning power loss P. loss.4_2The clutch housing oil churning analysis model includes the clutch housing, the clutch assembly space envelope (a closed whole), and the lubricating oil within the clutch mounting cavity. In this embodiment, P loss.4_2 =0.23kW.

[0188] Finally, using the formula: P loss.4 =P loss.4_1 +P loss.4_2 The power loss P of the clutch system under preset operating conditions in different modes was calculated. loss.4 (That is, the power loss of the fourth subsystem under preset operating conditions in different modes). In this embodiment, the power loss P of the clutch system under preset operating conditions in pure electric mode. loss.4 =0.339 + 0.23 = 0.569 kW; Power loss P of the clutch system under preset operating conditions in parallel mode or engine direct drive mode. loss.4 =0.2 + 0.23 = 0.43kW.

[0189] S35. Determine the power loss of the shifting system under preset operating conditions.

[0190] like Figure 11 As shown, the method for determining the power loss of the shifting system under preset operating conditions is as follows:

[0191] First, based on the geometric model of the i-th synchronizer, a simulation model of the drag loss of the i-th synchronizer is built. This simulation model considers the components of the synchronizer's friction pair (gear ring, idler gear, friction cone), the roughness and friction coefficient of the friction cone contact surface, the speed difference between the friction cones, the lubricating oil flow rate and performance parameters, and the synchronizer's operating temperature. Here, i takes any integer from 1 to n, and n is the total number of synchronizers in the shifting system (n is a known parameter). In this embodiment, n = 4.

[0192] Secondly, based on the drag loss simulation model of the i-th synchronizer, simulation analysis and calculation are performed to obtain the drag loss power P of the i-th synchronizer. sync·1oss_i Specifically:

[0193] If the geometric model of the i-th synchronizer has a friction cone at only one end, then the end of the geometric model of the i-th synchronizer without the friction cone is fixed, and the end with the friction cone is loaded with the rotational speed difference n of the friction cone of the i-th synchronizer. i Simulation analysis was performed to obtain the drag loss torque T of the i-th synchronizer. sync·1oss_i (When the friction cone of the i-th synchronizer engages, the speed difference n of the friction cone) i =0, drag loss torque Reusing the formula: P sync·loss_i =T sync·loss_i ×ni / 9549, the drag loss power P of the i-th synchronizer is calculated. sync·1oss_i Wherein, the speed difference n of the friction cone of the i-th synchronizer i It is obtained by converting the input shaft speed of the transmission under preset working conditions, the corresponding gear, and the shaft speed ratio (which belongs to the prior art).

[0194] If the geometric model of the i-th synchronizer has friction cones at both ends, then first fix the right end of the geometric model of the i-th synchronizer, and load the left end with the rotational speed difference n of the left friction cone of the i-th synchronizer. i_1 Simulation analysis was performed to obtain the drag loss torque T at the left end of the i-th synchronizer. sync·1oss_i_1 Then, fix the left end of the geometric model of the i-th synchronizer and load the right end with the rotational speed difference n of the right friction cone of the i-th synchronizer. i_2 Simulation analysis was performed to obtain the drag loss torque T at the right end of the i-th synchronizer. sync·loss_i_2 When the friction cone at one end of the i-th synchronizer engages and the friction cone at the other end disengages, the speed difference between the engaged and disengaged friction cones is zero, and the drag loss torque at the engaged end is also zero. For example, when the left friction cone of the i-th synchronizer engages and the right friction cone disengages, n i_1 =0,T sync·loss_i_1 =0, n i_2 ≠0, T sync·loss_i_2 ≠0. Then, using the formula: P sync.loss_i_1 =T sync.loss_i_1 ×n i_1 / 9549, P sync.loss_i_2 =T sync·loss_i_2 ×n i_2 / 9549, calculate the drag loss power P at the left end of the i-th synchronizer. sync·loss_i_1 and right-end drag power loss P sync·loss_i_2 Finally, using the formula: P sync·loss_i =P sync·loss_i_1 +P sync·loss_i_2 The drag loss power P of the i-th synchronizer is calculated. sync·loss_i Wherein, the speed difference n of the left friction cone of the i-th synchronizer i_1 The speed difference n between the right friction cone and the right friction cone i_2 It is obtained by converting the input shaft speed of the transmission under preset working conditions, the corresponding gear, and the shaft speed ratio (which belongs to the prior art).

[0195] Then, using the formula: The total power loss P of the synchronizer was calculated. sync·loss .

[0196] Finally, the total power loss P of the synchronizer is... sync·lossThe power loss P of the shifting system under preset operating conditions loss·5 (That is, the power loss of the fifth subsystem under the preset operating conditions). After calculation, in this embodiment, P... loss·5 =0.039kW.

[0197] The fourth step is to process the power loss of other subsystems besides the electric drive system under the preset operating conditions to obtain the total efficiency of other subsystems besides the electric drive system under the preset operating conditions.

[0198] Based on the above analysis, under the preset operating conditions, P loss·1 =0.57kW, P loss·2 =0kW, P loss·3 =0.006kW, P loss·5 =0.039kW, P in pure electric mode loss·4 =0.569kW, P in parallel mode or engine direct drive mode loss·4 =0.43kW. In this embodiment, the correlation coefficient between the power loss of the preset gear shaft system and the total power loss (i.e., the correlation coefficient between the power loss of the first subsystem and the total power loss) α1 = 1, the correlation coefficient between the power loss of the preset hydraulic system and the total power loss (i.e., the correlation coefficient between the power loss of the second subsystem and the total power loss) α2 = 1, the correlation coefficient between the power loss of the preset accessory system and the total power loss (i.e., the correlation coefficient between the power loss of the third subsystem and the total power loss) α3 = 1, the correlation coefficient between the power loss of the preset clutch system and the total power loss (i.e., the correlation coefficient between the power loss of the fourth subsystem and the total power loss) α4 = 1, and the correlation coefficient between the power loss of the preset shifting system and the total power loss (i.e., the correlation coefficient between the power loss of the fifth subsystem and the total power loss) α5 = 1.

[0199] The specific handling method is as follows:

[0200] First, use the formula: The total power loss P of the subsystems other than the electric drive system under the preset operating conditions was calculated. total.loss In this embodiment, under preset operating conditions, P in pure electric mode... total.loss =0.57+0+0.006+0.569+0.039=1.184kW, P in parallel mode or engine direct drive mode total.loss =0.57+0+0.006+0.43+0.039=1.045kW.

[0201] Reuse formula: The overall efficiency η of the subsystems other than the electric drive system under the preset operating conditions was calculated. other Among them, P inputP represents the input power of the electric drive transmission. input The values ​​are calculated based on the transmission input shaft speed (2500 rpm) and transmission input shaft torque (60 N·m) under preset operating conditions. In this embodiment, P... input =2500*60 / 9549=15.708kW. Under the preset operating conditions, the pure electric mode... Parallel mode or engine direct drive mode

[0202] Step 5: Based on the efficiency of each component in the electric drive system under preset operating conditions and the total efficiency of other subsystems under preset operating conditions, determine the overall efficiency of the P2 configuration electric drive transmission under preset operating conditions.

[0203] Using the formula: η ele_total_2 =B2×η 2M ×η 2M_control ×η other +C2×η other The overall efficiency η of the electric drive transmission with P2 configuration under preset operating conditions was calculated. ele_total_2 B2 and C2 are coefficients related to the operating mode of the electric drive transmission with P2 configuration, and B2+C2=1.

[0204] When the P2 configuration electric drive transmission is in pure electric mode, B2=1 and C2=0.

[0205] In pure electric mode, η ele_total_2 =1×η 2M ×η 2M_control ×η other = 1 × 96.35% × 98.05% × 92.46% = 87.35%. That is, in pure electric mode, the overall efficiency of the P2 configuration electric drive transmission under the preset operating conditions is 87.35%.

[0206] When the electric drive transmission of the P2 configuration operates in parallel mode, B2 = 0.3 and C2 = 0.7.

[0207] In parallel mode, η ele_total_2 =B2×η 2M ×η 2M_control ×η other +C2×η uther =0.3×η 2M ×η 2M_control ×η other +0.7×η other= 0.3 × 96.35% × 98.05% × 93.35% + 0.7 × 93.35% = 91.8%. That is, in parallel mode, the overall efficiency of the P2 configuration electric drive transmission under the preset operating conditions is 91.8%.

[0208] When the P2 configuration electric drive transmission operates in engine direct drive mode, B2=0 and C2=1.

[0209] In engine direct drive mode, η ele_total_2 =1×η other =1 × 93.35% = 93.35%. That is, in engine direct drive mode, the overall efficiency of the P2 configuration electric drive transmission under preset operating conditions is 93.35%.

[0210] Example 4: The electric drive transmission in this example is a P3 configuration electric drive transmission. The preset operating condition in this example refers to the operating condition where the transmission input shaft speed is 2500 rpm, the transmission input shaft torque is 60 N·m, and the lubricating oil temperature is 60°C. It should be noted that the preset operating condition can also be other operating conditions with known transmission input shaft speed, known transmission input shaft torque, and known lubricating oil temperature.

[0211] like Figure 12 , Figure 13 As shown, the method for estimating the overall efficiency of the electric drive transmission in this embodiment includes:

[0212] The first step is to break down the P3 configuration electric drive transmission into four subsystems based on its function or role. The four subsystems are: electric drive system, gear and shaft system, hydraulic system, and accessory system.

[0213] The second step is to decompose the electric drive system into a drive motor and a drive motor controller, and determine the efficiency of the drive motor and the drive motor controller under preset operating conditions.

[0214] Since the drive motor and drive motor controller in this embodiment are borrowed components with available efficiency test data, simulation is not required; the efficiency test data is used directly. Therefore, the efficiency η of the drive motor under the preset operating conditions is obtained. TM =96.75%, the efficiency of the drive motor controller under the preset operating conditions is η TM_control =98.25%.

[0215] If there is no efficiency test data for the motor and motor controller, then it is necessary to perform efficiency simulation of the motor and motor controller (which is existing technology) to obtain the efficiency of the motor and motor controller under preset operating conditions.

[0216] The third step is to determine the power loss of other subsystems besides the electric drive system under preset operating conditions. (See details for specific steps.) Figure 13 )include:

[0217] S41. Determine the power loss of the gear shaft system under preset operating conditions.

[0218] The method for determining the power loss of the gear shaft system under preset operating conditions in this embodiment is the same as in Embodiment 3, and will not be described in detail here. The power loss of the gear shaft system under preset operating conditions (i.e., the power loss of the first subsystem under preset operating conditions) P in this embodiment is... loss.1 =0.62kW.

[0219] S42. Determine the power loss of the hydraulic system under preset operating conditions.

[0220] Since the P3 configuration electric drive transmission uses an electronic oil pump, the power loss of the electronic oil pump is 0kW in the efficiency simulation. Therefore, the power loss of the hydraulic system under the preset operating conditions (i.e., the power loss of the second subsystem under the preset operating conditions) P loss.2 =0kW.

[0221] S43. Determine the power loss of the accessory system under preset operating conditions.

[0222] The method for determining the power loss of the accessory system under the preset operating conditions in this embodiment is the same as in Embodiment 3, and will not be described in detail here. The power loss of the accessory system under the preset operating conditions (i.e., the power loss of the third subsystem under the preset operating conditions) P in this embodiment is... loss.3 =0.007kW.

[0223] The fourth step is to process the power loss of other subsystems besides the electric drive system under the preset operating conditions to obtain the total efficiency of other subsystems besides the electric drive system under the preset operating conditions.

[0224] Based on the above analysis, under the preset operating conditions, P loss.1 =0.62kW, P loss.2 =0kW, P loss.3 =0.007kW. In this embodiment, the correlation coefficient between the power loss of the kth subsystem and the total power loss is preset to be 1, that is, α1=α2=α3=1.

[0225] The specific handling method is as follows:

[0226] First, use the formula: The total power loss P of the subsystems other than the electric drive system under the preset operating conditions was calculated. total.loss。 In this embodiment, P total.loss =0.62+0+0.007=0.627kW.

[0227] Reuse formula: The overall efficiency η of the subsystems other than the electric drive system under the preset operating conditions was calculated.other Among them, P input P represents the input power of the electric drive transmission. input The values ​​are calculated based on the transmission input shaft speed (2500 rpm) and transmission input shaft torque (60 N·m) under preset operating conditions. In this embodiment, P... input =2500*60 / 9549=15.708kW

[0228] Step 5: Based on the efficiency of each component in the electric drive system under preset operating conditions and the total efficiency of other subsystems under preset operating conditions, determine the overall efficiency of the P3 configuration electric drive transmission under preset operating conditions.

[0229] Using the formula: η ele_total_3_4 =η TM × TM_control ×η other The overall efficiency η of the electric drive transmission with P3 configuration under preset operating conditions was calculated. ele_total_3_4 In this embodiment, η ele_total_34 = 96.75% × 98.25% × 96.01% = 91.26%. That is, the overall efficiency of the P3 configuration electric drive transmission under the preset operating conditions is 91.26%.

[0230] Furthermore, the method for estimating the overall efficiency of the electric drive transmission with the P4 configuration is the same as that for the P3 configuration.

Claims

1. A method for estimating the overall efficiency of an electric drive transmission, characterized in that, include: Step 1: Based on function or purpose, the electric drive transmission is broken down into multiple subsystems; Step 2: When the subsystem is an electric drive system, determine the efficiency of each component in the electric drive system under preset operating conditions; when the subsystem is another subsystem besides the electric drive system, first determine the power loss of the other subsystem under preset operating conditions, and then process it to obtain the total efficiency of the other subsystem under preset operating conditions. Step 3: Based on the efficiency of each component in the electric drive system under preset operating conditions and the total efficiency of the other subsystems under preset operating conditions, determine the overall efficiency of the electric drive transmission under preset operating conditions. If the electric drive transmission is a P13 configuration electric drive transmission, then the components in the electric drive system are: P1 motor, P1 motor controller, P3 motor and P3 motor controller. Using the formula: The overall efficiency of the electric drive transmission with P13 configuration under preset operating conditions was calculated. ; in, This indicates the efficiency of motor P1 under preset operating conditions. This indicates the efficiency of the P1 motor controller under preset operating conditions. This indicates the efficiency of motor P3 under preset operating conditions. This indicates the efficiency of the P3 motor controller under preset operating conditions. This indicates the overall efficiency of the P3 path's subsystems, excluding the electric drive system, under preset operating conditions. This represents the total efficiency of the subsystems other than the electric drive system in the P1 path under the preset operating conditions. A1, B1, and C1 are coefficients related to the operating mode of the electric drive transmission in the P13 configuration, and A1+B1+C1=1.

2. The method for estimating the overall efficiency of an electric drive transmission according to claim 1, characterized in that: When the electric drive transmission of the P13 configuration operates in series mode, A1=1, B1=C1=0; When the electric drive transmission of the P13 configuration is in pure electric mode, B1=1, A1=C1=0; When the electric drive transmission of the P13 configuration is in parallel mode, A1=0, B1≠0, C1≠0, B1 equals the preset first coefficient value, and C1 equals the preset second coefficient value. When the electric drive transmission of the P13 configuration is in engine direct drive mode, A1=B1=0, C1=1; When the electric drive transmission of the P13 configuration is in the parallel-parallel mode I, A1≠0, B1≠0, C1≠0, A1 equals the preset third coefficient value, B1 equals the preset fourth coefficient value, and C1 equals the preset fifth coefficient value. When the electric drive transmission of the P13 configuration is in the hybrid mode II, A1≠0, B1≠0, C1=0, A1 equals the preset sixth coefficient value, and B1 equals the preset seventh coefficient value. When the electric drive transmission of the P13 configuration is in the parallel-parallel mode III, A1≠0, B1=0, C1≠0, A1 equals the preset eighth coefficient value, and C1 equals the preset ninth coefficient value.

3. The method for estimating the overall efficiency of an electric drive transmission according to claim 1 or 2, characterized in that: The overall efficiency of the P1 path subsystems other than the electric drive system under preset operating conditions is obtained through processing. The method is as follows: First, use the formula: The total power loss of the P1 path other than the electric drive system under the preset operating conditions was calculated. ; Reuse formula: The overall efficiency of the P1 path other than the electric drive system under the preset operating conditions was calculated. ; Where m represents the total number of subsystems other than the electric drive system in the P13 configuration electric drive transmission. This represents the power loss of the k-th subsystem in path P1 (excluding the electric drive system) under the preset operating conditions. This represents the correlation coefficient between the power loss of the k-th subsystem (excluding the electric drive system) and the total power loss. This indicates the input power of the P1 path of the electric drive transmission. The values ​​are calculated based on the transmission input shaft speed and transmission input shaft torque under preset operating conditions in the P1 path.

4. The method for estimating the overall efficiency of an electric drive transmission according to claim 3, characterized in that: The overall efficiency of the P3 path subsystems other than the electric drive system under preset operating conditions is obtained through processing. The method is as follows: First, use the formula: The total power loss of the P3 path subsystems other than the electric drive system under the preset operating conditions was calculated. ; Reuse formula: The overall efficiency of the P3 path subsystems other than the electric drive system under the preset operating conditions was calculated. ; in, This represents the power loss of the k-th subsystem in path P3, excluding the electric drive system, under preset operating conditions. This indicates the input power of the P3 path in the electric drive transmission. The values ​​are calculated based on the transmission input shaft speed and transmission input shaft torque under preset operating conditions in the P3 path.

5. The method for estimating the overall efficiency of an electric drive transmission according to claim 4, characterized in that: If the electric drive transmission of the P13 configuration is a single-speed electric drive transmission, then the electric drive transmission of the P13 configuration is decomposed into 5 subsystems, namely: electric drive system, gear shaft system, hydraulic system, accessory system and clutch system. ； ； in, This represents the power loss of the gear shaft system along path P1 under the preset operating conditions. This represents the power loss of the hydraulic system along path P1 under preset operating conditions. This indicates the power loss of the auxiliary system along path P1 under preset operating conditions. This indicates the power loss of the clutch system in the P1 path under the preset operating conditions. This represents the power loss of the gear shaft system along path P3 under the preset operating conditions. This represents the power loss of the hydraulic system along path P3 under preset operating conditions. This indicates the power loss of the auxiliary system along path P3 under preset operating conditions. This indicates the power loss of the clutch system in the P3 path under preset operating conditions. This represents the correlation coefficient between the preset power loss of the gear shaft system and the total power loss. This represents the correlation coefficient between the preset power loss of the hydraulic system and the total power loss. This represents the correlation coefficient between the preset power loss of the accessory system and the total power loss. This represents the correlation coefficient between the preset power loss of the clutch system and the total power loss.

6. The method for estimating the overall efficiency of an electric drive transmission according to claim 4, characterized in that: If the electric drive transmission of the P13 configuration is a multi-speed electric drive transmission, then the electric drive transmission of the P13 configuration is decomposed into 6 subsystems, namely: electric drive system, gear shaft system, hydraulic system, accessory system, clutch system and shifting system. ； ； in, This represents the power loss of the gear shaft system along path P1 under the preset operating conditions. This represents the power loss of the hydraulic system along path P1 under preset operating conditions. This indicates the power loss of the auxiliary system along path P1 under preset operating conditions. This represents the power loss of the clutch system in path P1 under preset operating conditions. This indicates the power loss of the shifting system in path P1 under preset operating conditions; This represents the power loss of the gear shaft system along path P3 under the preset operating conditions. This represents the power loss of the hydraulic system along path P3 under preset operating conditions. This indicates the power loss of the auxiliary system along path P3 under preset operating conditions. This indicates the power loss of the clutch system in the P3 path under preset operating conditions. This indicates the power loss of the shifting system in the P3 path under preset operating conditions; This represents the correlation coefficient between the preset power loss of the gear shaft system and the total power loss. This represents the correlation coefficient between the preset power loss of the hydraulic system and the total power loss. This represents the correlation coefficient between the preset power loss of the accessory system and the total power loss. This represents the correlation coefficient between the preset power loss of the clutch system and the total power loss. This represents the correlation coefficient between the preset power loss of the shifting system and the total power loss.

7. A method for estimating the overall efficiency of an electric drive transmission, characterized in that, include: Step 1: Based on function or purpose, the electric drive transmission is broken down into multiple subsystems; Step 2: When the subsystem is an electric drive system, determine the efficiency of each component in the electric drive system under preset operating conditions; when the subsystem is another subsystem besides the electric drive system, first determine the power loss of the other subsystem under preset operating conditions, and then process it to obtain the total efficiency of the other subsystem under preset operating conditions. Step 3: Based on the efficiency of each component in the electric drive system under preset operating conditions and the total efficiency of the other subsystems under preset operating conditions, determine the overall efficiency of the electric drive transmission under preset operating conditions. If the electric drive transmission is a P2 configuration electric drive transmission, then the components in the electric drive system are: P2 motor and P2 motor controller. Using the formula: The overall efficiency of the electric drive transmission with P2 configuration under preset operating conditions was calculated. ; in, This indicates the efficiency of motor P2 under preset operating conditions. This indicates the efficiency of the P2 motor controller under preset operating conditions. This represents the total efficiency of the subsystems other than the electric drive system under preset operating conditions. B2 and C2 are coefficients related to the operating mode of the electric drive transmission with P2 configuration. B2+C2=1.

8. The method for estimating the overall efficiency of an electric drive transmission according to claim 7, characterized in that: When the electric drive transmission of the P2 configuration is in pure electric mode, B2=1 and C2=0. When the electric drive transmission of the P2 configuration is in parallel mode, B2≠0, C2≠0, B2 equals the preset tenth coefficient value, and C2 equals the preset eleventh coefficient value. When the P2 configuration electric drive transmission operates in engine direct drive mode, B2=0 and C2=1.

9. A method for estimating the overall efficiency of an electric drive transmission, characterized in that, include: Step 1: Based on function or purpose, the electric drive transmission is broken down into multiple subsystems; Step 2: When the subsystem is an electric drive system, determine the efficiency of each component in the electric drive system under preset operating conditions; when the subsystem is another subsystem besides the electric drive system, first determine the power loss of the other subsystem under preset operating conditions, and then process it to obtain the total efficiency of the other subsystem under preset operating conditions. Step 3: Based on the efficiency of each component in the electric drive system under preset operating conditions and the total efficiency of the other subsystems under preset operating conditions, determine the overall efficiency of the electric drive transmission under preset operating conditions. If the electric drive transmission is a P3 or P4 configuration, then the components in the electric drive system are: the drive motor and the drive motor controller. Using the formula: The overall efficiency of the electric drive transmission with P3 or P4 configuration under preset operating conditions is calculated. ; in, This indicates the efficiency of the drive motor under preset operating conditions. This indicates the efficiency of the drive motor controller under preset operating conditions. This indicates the overall efficiency of all subsystems other than the electric drive system under preset operating conditions.

10. The method for estimating the overall efficiency of an electric drive transmission according to any one of claims 7 to 9, characterized in that: The processing yields the overall efficiency of all subsystems except the electric drive system under preset operating conditions. The method is as follows: First, use the formula: The total power loss of other subsystems besides the electric drive system under the preset operating conditions was calculated. ; Reuse formula: The overall efficiency of the subsystems other than the electric drive system under the preset operating conditions was calculated. ; Where v represents the total number of subsystems other than the electric drive system in the electric drive transmission. This represents the power loss of the j-th subsystem (excluding the electric drive system) under preset operating conditions. This represents the correlation coefficient between the power loss of the j-th subsystem (excluding the electric drive system) and the total power loss. Indicates the input power of the electric drive transmission. It is calculated based on the transmission input shaft speed and transmission input shaft torque under preset operating conditions.

11. The method for estimating the overall efficiency of an electric drive transmission according to claim 10, characterized in that: The P2 configuration electric drive transmission is broken down into 6 subsystems: electric drive system, gear shaft system, hydraulic system, accessory system, clutch system, and shifting system. ； in, This indicates the power loss of the gear shaft system under preset operating conditions. This indicates the power loss of the hydraulic system under preset operating conditions. This indicates the power loss of the accessory system under preset operating conditions. This indicates the power loss of the clutch system under preset operating conditions. This indicates the power loss of the shifting system under preset operating conditions; This represents the correlation coefficient between the preset power loss of the gear shaft system and the total power loss. This represents the correlation coefficient between the preset power loss of the hydraulic system and the total power loss. This represents the correlation coefficient between the preset power loss of the accessory system and the total power loss. This represents the correlation coefficient between the preset power loss of the clutch system and the total power loss. This represents the correlation coefficient between the preset power loss of the shifting system and the total power loss.

12. The method for estimating the overall efficiency of an electric drive transmission according to claim 10, characterized in that: The electric drive transmission with P3 or P4 configuration is broken down into four subsystems: electric drive system, gear shaft system, hydraulic system, and accessory system. ； in, This indicates the power loss of the gear shaft system under preset operating conditions. This indicates the power loss of the hydraulic system under preset operating conditions. This indicates the power loss of the accessory system under preset operating conditions; This represents the correlation coefficient between the preset power loss of the gear shaft system and the total power loss. This represents the correlation coefficient between the preset power loss of the hydraulic system and the total power loss. This represents the correlation coefficient between the preset power loss of the accessory system and the total power loss.

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