Optimisation of an Electric Drive Train for ‘On Road’ Electric Vehicle

The on road performance of an Electric Vehicle is, to a large extent dependent on the performance of the drive train. The drive train determines how efficiently the energy in batteries is used to meet the driving requirements on road. The importance of efficiency is well known. With a ‘limited’ energy storage availability on board, it is important to see that the conversion of watt hours to kms happens in the most efficient manner. Also, in order to make driving simple and offer the best ‘on road’ convenience to customers, it is necessary to understand driving patterns and preferences of customers.

This paper details the optimization of a drive train and development of ‘driving modes’ for an electric vehicle for use in India and Europe. The exercise involves the following major activities

• Design of the drive train involving a motor and gears
• Optimisation of the characteristics of the motor and achievement of the torque speed and efficiency requirements
• User trials in Europe and India to map usage patterns and preferences
• Formulation of ‘selectable’ drive maps, and implementation in the drive system software.

The initial tests are followed by actual running of a number of pilot cars and testing.