An efficiency control strategy of dual-motor multi-gear drive algorithm

Figures & data

Figure 1. Dual motor multi-speed coupling drive system.

Table 1. Operating status table of motor and synchroniser in each mode.

Mode	Motor 1	Motor 2	Synchronizer 1	Synchronizer 2
SM1-1	•	⊖	$\to$	$\oslash$
SM1-2	•	⊖	$\leftarrow$	$\oslash$
SM2-1	⊖	•	$\oslash$	$\to$
SM2-2	⊖	•	$\oslash$	$\leftarrow$
DM1-1	•	•	$\to$	$\to$
DM2-1	•	•	$\leftarrow$	$\to$
DM2-2	•	•	$\leftarrow$	$\leftarrow$
DM1-2	•	•	$\to$	$\leftarrow$

Note: “•” means the corresponding motor is in starting state, “⊖” means the corresponding motor is in stopping state, “$\to$” means the corresponding synchroniser's bonding sleeve and right side bonding, “$\leftarrow$” means the corresponding synchroniser's bonding sleeve left side bonding, “$\oslash$” means the corresponding synchroniser's bonding sleeve empty sleeve.

Table 2. Overall vehicle parameters.

Parameters	Numerical value
Overall vehicle mass m(kg)	1780
Wheel rolling radius r(m)	0.317
Rolling resistance coefficient f	0.015
Windward area A(m)	2.1
Air resistance coefficient Cd	0.3
Car rotating mass conversion factor δ	2.1
Maximum speed(Km/h)	180
Battery voltage(V)	372
Battery Capacity(Ah)	72
Battery power(KWh)	26.78
M1/M2 peak power(KW)	23.5/61.5
M1/M2 peak torque(Nm)	60/170
M1/M2 rated speed(rpm)	3740/3455
M1/M2 maximum speed(rpm)	11500/9500
M1-1 /M1-2(i1_1/ i1_2)	1.667/1
M2-1/ M2-2(i2_1/ i2_2)	1.2558/0.7378
Main reduction ratio(i0)	7

Figure 2. External characteristics of the drive system.

Figure 3. MAP diagram of economic motor and power motor. (a) Economic motor MAP diagram (b) Power motor MAP diagram.

Figure 4. Power consumption in different modesr. (a) Low-speed high-torque coupling case (b) High-speed high-torque coupling case.

Figure 5. Power consumption at different torques. (a) Power consumption in DM1-1 mode (b) Power consumption in DM2-2 mode.

Figure 6. Drive mode division. (a) 8 types of drive mode division (b) 6 types of drive mode division.

Figure 7. DM1-1 mode switching DM2-2 mode flow.

Figure 8. SM1-1 mode switch SM2-1 mode flow chart.

Figure 9. AMESim and MATLAB joint simulation model. (a) AMESim Dual Motor Multi-Shift System Physical Model (b) Simulink control model for dual motor multi-speed system.

Figure 10. Cycle working condition and SOC variation graph. (a) NEDC cycle work following situation (b) UDDS cycle work following situation (c) 10–15 Circulating conditions follow (d) Comparison of the change of SOC in single cycle working condition.

Figure 11. UDDS acceleration section M1, M2 actual operation. (a) M1 Workpoint Distribution (b) M2 work point distribution.

Figure 12. DM1-1 mode switching DM2-2 mode simulation results. (a) Synchronizer 1 binding sleeve position (b) Synchronizer 2 binding sleeve position (c) M1, M2 torque following situation (d) Output torque during mode switching (e) Impact degree during mode switching.

Figure 13. SM1-1 mode switching SM2-1 mode simulation results. (a) Synchronizer 1 binding sleeve position (b) Synchronizer 2 binding sleeve position (c) M1, M2 torque following situation (d) Output torque during mode switching (e) Change in impact degree during mode switching.