Power-Flow in Two And Three-Wheeled Road Electric Vehicles: Challenges and Opportunities

The need for vehicle electrification is growing across the world. However, increased cost and packaging volume considerations arising out of electrification, pose a major barrier to the adoption of electrified vehicles. One of the ways to alleviate cost and packaging volume concerns is through appropriate rating and sizing of the electric powertrain, which is influenced by several factors including power flow magnitude, energy storage capability, thermal limits, voltage and current limits, and packaging requirements. This paper presents practical power-flow considerations in the electric powertrain, associated challenges and potential directions towards reducing the cost and packaging volume of the e-drive system. The target vehicle segment considered for electrification in this study are two-wheeled and three-wheeled road vehicles, which are dominant segments of India's vehicle population. Electrification of this segment is expected to result in significant benefits, both for market penetration as well as the environment. The vehicle considered in the study consists of an e-drive system using a 48 V battery pack, connected to a three-phase power electronic inverter supplying a single electric machine for traction. Limits on e-drive system efficiency under these practical conditions for a range of torque-speed operating points are also discussed.