The document discusses different configurations for electric vehicles (EVs). It notes that early EVs converted internal combustion engine vehicles, which led to problems, while modern EVs are purpose-built. The key subsystems of a modern EV drive train are the electric motor propulsion system, the energy source, and auxiliary systems. The document then describes six possible EV configurations, including using a conventional drivetrain with gearbox and clutch, a single fixed gear transmission without clutch, integrated fixed gearing and differential, two separate motors with fixed gearing, direct drive with two motors and gearing, and two separate in-wheel motor drives.

1. Lecture: 5
Electric and Hybrid
Vehi
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Electric and Hybrid Vehicles

2. Lecture: 5
Configuration of EV
Electric and Hybrid Vehicles

3. • Previously, EV was mainly converted from the existing ICEVby
replacing the IC engine and fuel tank with an electric motor and
battery pack while retaining all the other components.
• There were several drawbacks: heavy weight, lower flexibility and
degraded performance. This caused such type of EV to fade out.
• Modern EV is purposely built, based on original body and frame
designs.
• This satisfies the structure requirements unique to EVs and makes
use of the greater flexibility of electric propulsion.
3Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

4. 4Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

5. • Modern electric drive train is as shown below
5Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

6. • The drive train consists of three major subsystems:
• i) Electric motor propulsion,
• ii) Energy source and
• iii)Auxiliary.
6Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

7. • i) Electric motor propulsion subsystem:
• - comprised of the vehicle controller, power electronic converter,
electric motor, mechanical transmission and the driving wheels.
• ii) Energy source subsystem:
• - involves the energy source, energy management unit and energy
refueling unit.
• iii) Auxiliary subsystem:
• - consists of the power steering unit, hotel climate control unit and
auxiliary supply unit.
7Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

8. • Based on the control inputs from the accelerator and brake pedals,
the vehicle controller provides proper control signals to the
electronic power converter, which functions to regulate the power
flow between the electric motor and the energy source.
• The backward power flow is due to the regenerative braking of the
EV and this regenerated energy can be restored into the energy
source, provided the energy source is receptive(batteries, supercap
and flywheels).
• Energy management unit cooperates with the vehicle controller to
control the regenerative braking and energy recovery.
• It also works with the energy refueling unit to control the refueling
unit and to monitor the usability of the energy source.
• Aux power supply provides the necessary power with different
voltage levels for all EV auxiliaries especially climate controland
power steering units.
8Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

9. The possible EV configurations are:
a) Conventional driveline with multi-gear transmission and clutch
b) Single gear transmission without need of a clutch
c) Integrated fixed gearing and differential
d) Two separate motors and fixed gearing with their driveshaft
e) Direct drive with two separate motors and fixed gearing
f) Two separate in-wheel motor drives
9Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE
Configurations of EV

10. a. Conventional driveline with multi-gear transmission and clutch
• Electric propulsion replaces the IC engine of a conventionalvehicle
drive train.
• Consists of electric motor, a clutch, a gearbox and a differential.
• Clutch is used to connect or disconnect the power of electric motor
from the driven wheels.
• Gearbox provides a set of gear ratios to modify the speed-power
profile to match the load requirement.
• Differential is a mechanical device, which enables the wheels of
both sides to be driven at different speeds when the vehicle runs
along a curved path.
10Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

11. 11Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

12. b. Single gear transmission without need of a clutch
• With an electric motor that has a constant power in a long speed
range, a fixed gearing can replace the multi speed gearbox and
reduce the need of a clutch.
• This configuration reduces the size and weight of the mechanical
transmission. Also simplifies the drive train because gear shiftingis
not needed.
12Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

13. c. Integrated fixed gearing and differential
• Similar to (b), the electric motor, fixed gearing and the differential
can be further integrated into a single assembly while both axle
points at both driving wheels.
• Whole drive train is further simplified and compacted.
13Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

14. d. Two separate motors and fixed gearing with their driveshaft
• The mechanical differential is replaced by two traction motors.
• Each of them drives one side wheel and operates at a different
speed when the vehicle is running along a curved path.
14Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

15. e. Direct drive with two separate motors and fixed gearing
• Traction motor is place inside a wheel. This arrangement so called
in-wheel drive.
• A thin planetary gear set may be employed to reduce the motor
speed and enhance the motor torque.
15Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

16. f. Two separate in-wheel motor drives
• By fully abandoning any mechanical gearing between the electric
motor and the driving wheels, the outer rotor of a low speed electric
motor in the in-wheel drive can be directly connected to the driving
wheel.
• Speed control of the electric motor is equivalent to the control of
the wheel speed and hence the vehicle speed.
• However, this arrangement requires the electric motor to have a
higher torque to start and accelerate the vehicle
16Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE

17. THANK YOU
17Electric and Hybrid Vehicles2-Aug-16 Mr.Ajayan. S, Asst. Prof. - EEE