Electric Drives and Power Chargers: Recent Solutions to Improve Performance and Energy Efficiency for Hybrid and Fully Electric Vehicles
Sergio Saponara, Christopher H. T. Lee, Nelson Xuntuo Wang, James L. Kirtley
Abstract
This article offers a survey of recent solutions involving electric drives and power chargers for fully electric vehicles (EVs) and hybrid EVs (HEVs). Based on our research and experimental activities regarding electric drives, we also show experimental data from prototypes. After reviewing the opportunities and challenges of vehicle electrification, the article analyzes electric machines and power converters for two main market trends: 1) low-voltage (48-V) HEVs, allowing for a smooth transition from internal combustion engine vehicles (ICEVs), and 2) full EVs, operating above 200 V. First, we discuss a 48-V integrated belt-driven starter generator (BSG), together with its tightly coupled power control electronics. Substituting a 12-V alternator, the BSG provides torque assistance to ICEVs for lowspeed, start-stop and regenerative-braking functionalities, and electric power generation for onboard loads. Instead, new topologies of electric machines are needed for full EVs.