Introduction
The topics covered in this chapter are as follows:
- • Electric Vehicle (EV) Configuration
• EV alternatives based on drivetrains
• EV alternatives based on power source configuration
• Single and Multi-motor drives
• IN wheel drives
Electric Vehicle (EV) Configurations
Compared to HEV, the configuration of EV is flexible. The reasons for this flexibility are:
- • The energy flow in EV is mainly via flexible electrical wires rather than bolted flanges or rigid shafts. Hence, distributed subsystems in the EV are really achievable.
• The EVs allow different propulsion arrangements such as independent four wheel and in wheel drives.
In Figure 1 the general configuration of the EV is shown. The EV has three major subsystems:
- • Electric propulsion
• Energy source
• Auxiliary system
The electric propulsion subsystem comprises of:
- • The electronic controller
• Power converter
• Electric Motor (EM)
• Mechanical transmission
• Driving wheels
The energy source subsystem consists of
- • The energy source (battery, fuel cell, ultracapacitor)
• Energy management unit
• Energy refueling unit
The auxiliary subsystem consists of
- • Power steering unit
• Temperature control unit
• Auxiliary power supply
In Figure 1 the black line represents the mechanical link, the green line represents the electrical link and the blue line represents the control information communication. Based on the control inputs from the brake and accelerator pedals, the electronic controller provides proper control signals to switch on or off the power converter which in turn regulates the power flow between the electric motor and the energy source. The backward power flow is due to regenerative braking of the EV and this regenerative energy can be stored provided the energy source is receptive.
The energy management unit cooperates with the electronic controller to control regenerative braking and its energy recovery. It also works with the energy-refueling unit to control refueling and to monitor usability of the energy source.
The auxiliary power supply provides the necessary power with different voltage levels for all EV auxiliaries, especially the temperature control and power steering units.