Dual-rotor motor for electric vehicles with a continuously variable transmisssion system with planet gear and control method thereof

An optimal energy economical control method for a drive system for an electric vehicle comprising:

• determining a motor running mode to be a driving mode, or a braking energy feedback mode with a vehicle controller according to a running state of the vehicle, a battery state of charge (SOC), states and time rates of changes of an accelerator pedal and a brake pedal, and then determining a working torque T3 of a dual-rotor motor for the electric vehicle;
• then sending the motor running mode and a torque instruction to a controller for an inner motor subsystem and a controller for an outer motor subsystem, then with the controller for the inner motor subsystem and the controller for the outer motor subsystem, determining torques T1, T2 that an inner rotor and an outer rotor should provide according to a topological structure of the drive system and tooth numbers of a ring gear and a sun gear, calculating an output rotating speed ω3 according to speed of the electric vehicle and dynamic radius of a wheel of the electric vehicle, then in real time calculating optimal working rotating speeds of the inner rotor and the outer rotor at this time according to an efficiency curve of the inner motor subsystem and the outer motor subsystem, wherein:
• max└ηsys┘=max└ηsys1(T1,ω1)·ηsys2(T2,ω2)┘, (2)
• T1=f(T3,Na,Ns), (3)
• T2=f(T3,Na,Ns), (4)
• ω3=f(ω1,ω2,Na,Ns), (5)
• wherein, ηsys is a total system efficiency, ηsys1 is a comprehensive system efficiency of the controller for the inner motor subsystem, the inner three-phase winding and the inner rotor;
• ηsys2 is a comprehensive system efficiency of the controller for the outer motor subsystem, the outer three-phase winding and the outer rotor;
• T1 is target torque that the inner rotor should provide;
• T2 is target torque that the outer rotor should provide;
• ω1 is optimal working rotating speed of the inner rotor at this time;
• ω2 is optimal working rotating speed of the outer rotor at this time;
• and
• wherein the drive system comprises:
• a dual rotor motor in mechanical communication with a continuously variable transmission system, and a vehicle controller, the dual rotor motor comprising:
• a housing;
• an output shaft;
• an outer rotor;
• and a stator located inside the housing, the output shaft being at least partly located in the housing and arranged rotatably relative to the housing, the stator being sleeved around the output shaft, an outer three-phase winding being arranged outside the stator, the outer rotor being sleeved around the outer three-phase winding and arranged rotatably relative to the stator, characterized in that, the dual-rotor motor for electric vehicle further comprises an inner rotor, an inner three-phase winding is arranged inside the stator, the inner rotor is inserted in the inner three-phase winding around the output shaft and arranged rotatably relative to the stator, thus the inner three-phase winding and the inner rotor constitute an inner motor subsystem, the outer three-phase winding and the outer rotor constitute an outer motor subsystem;
• and
• wherein the continuously variable transmission comprises:
• a planet gear;
• a set of ring gears;
• a planet carrier;
• a sun gear;
• and
• wherein the outer rotor of the dual rotor motor is connected with at least one of a first ring gear of the set of ring gears, the planet carrier, and the sun gear of the planet gear, the inner rotor is connected with at least one of a second ring gear of the set of ring gears, the planet carrier and the sun gear, and the output shaft of the dual rotor motor is connected with a third ring gear of the set of ring gears, the planet carrier and the sun gear.

An optimal energy economical control method for a drive system for an electric vehicle comprising:

• determining a motor running mode to be a driving mode, or a braking energy feedback mode with a vehicle controller according to a running state of the vehicle, a battery state of charge (SOC), states and time rates of changes of an accelerator pedal and a brake pedal, and then determining a working torque T3 of a dual-rotor motor for electric vehicle;
• then sending the motor running mode and a torque instruction to a motor controller, then with the motor controller, determining torques T1, T2 that an inner rotor and an outer rotor should provide according to a topological structure of the drive system and tooth numbers of a ring gear and a sun gear, calculating an output rotating speed ω3 according to vehicle speed and dynamic radius of a wheel of the electric vehicle wheel, then in real time calculating optimal working rotating speeds of the inner rotor and the outer rotor at this time according to an efficiency curve of the inner motor subsystem and the outer motor subsystem, wherein:
• max
• ⁡
• [
• η
• sys
• ]
• =
• max
• ⁡
• [
• η
• m
• ⁢
• ⁢
• 1
• ⁡
• (
• T
• 1
• ,
• ω
• 1
• )
• ⁢
• T
• 1
• ⁢
• ω
• 1
• +
• η
• m
• ⁢
• ⁢
• 2
• ⁡
• (
• T
• 2
• ,
• ω
• 2
• )
• ⁢
• T
• 2
• ⁢
• ω
• 2
• T
• 1
• ⁢
• ω
• 1
• +
• T
• 2
• ⁢
• ω
• 2
• ⁢
• η
• c
• ⁡
• (
• T
• 1
• ,
• ω
• 1
• ,
• T
• 2
• ,
• ω
• 2
• )
• ]
• ,
• (
• 7
• )
• ⁢
• T
• 1
• =
• f
• ⁡
• (
• T
• 3
• ,
• N
• a
• ,
• N
• s
• )
• ,
• (
• 3
• )
• ⁢
• T
• 2
• =
• f
• ⁡
• (
• T
• 3
• ,
• N
• a
• ,
• N
• s
• )
• ,
• (
• 4
• )
• ⁢
• ω
• 3
• =
• f
• ⁡
• (
• ω
• 1
• ,
• ω
• 2
• ,
• N
• a
• ,
• N
• s
• )
• ,
• (
• 5
• )
• wherein, ηsys is a total system efficiency, ηm1(T1,ω1) is a system efficiency of the inner motor subsystem;
• ηm2(T2,ω2) is a system efficiency of the outer motor subsystem;
• ηc(T1,ω1,T2,ω2) is an efficiency of the motor controller;
• T1 is target torque that the inner rotor should provide;
• T2 is target torque that the outer rotor should provide;
• ω1 is optimal working rotating speed of the inner rotor at this time;
• ω2 is optimal working rotating speed of the outer rotor at this time;
• and
• wherein the drive system comprises:
• a dual rotor motor in mechanical communication with a continuously variable transmission system, and a vehicle controller, the dual rotor motor comprising:
• a housing;
• an output shaft;
• an outer rotor;
• and a stator located inside the housing, the output shaft being at least partly located in the housing and arranged rotatably relative to the housing, the stator being sleeved around the output shaft, an outer three-phase winding being arranged outside the stator, the outer rotor being sleeved around the outer three-phase winding and arranged rotatably relative to the stator, characterized in that, the dual-rotor motor for electric vehicle further comprises an inner rotor, an inner three-phase winding is arranged inside the stator, the inner rotor is inserted in the inner three-phase winding around the output shaft and arranged rotatably relative to the stator, thus the inner three-phase winding and the inner rotor constitute an inner motor subsystem, the outer three-phase winding and the outer rotor constitute an outer motor subsystem;
• and
• wherein the continuously variable transmission comprises:
• a planet gear;
• a set of ring gears;
• a planet carrier;
• a sun gear;
• and
• wherein the outer rotor of the dual rotor motor is connected with at least one of a first ring gear of the set of ring gears, the planet carrier, and the sun gear of the planet gear, the inner rotor is connected with at least one of a second ring gear of the set of ring gears, the planet carrier and the sun gear, and the output shaft of the dual rotor motor is connected with a third ring gear of the set of ring gears, the planet carrier and the sun gear.