Comprehensive PM motor controller design for electrically assisted turbo-charger systems

A hybrid position sensorless motor control strategy is developed to meet the challenges of electrically assisted turbo-charger (EATC) systems integrated into an automotive engine plant. The proposed controller has a straightforward structure with properties that combines the conventional current vector controller (CVC) and the proposed hexagon voltage modulation controller (HVMC). The proposed HVMC accomplishes the maximum available voltage utilization, allowing a larger motor torque generation per ampere than that of current control alone in the 2^nd flux weakening region. This feature leads to a higher PM flux linkage of the motor design, which lets us capture the reliable back-EMF information at the starting speed. In addition, setting a lower bound of the base speed can be achieved to avoid non-ideal current regulation problems at higher speeds. The proposed structure can offer further flexibilities in motor design and drive control, beyond a conventional turbo-charger.