Self-sensing control of the externally-excited synchronous machine for electric vehicle traction application

This paper studies the possibility of removing the position sensor from electric vehicles (EVs) powertrains that employ the externally-excited synchronous machine (EESM) for traction. Three position estimation approaches are studied: back-electromotive-force integration, state-observer and high-frequency voltage injection approaches. Theoretical background is presented, a comparative performance analysis is performed, and experimental results on a 65-kW EESM drive test bench are shown. Some requirements for EV powertrains are emphasized.