Date of Award

Fall 2014

Document Type


Degree Name

Master of Science (MS)


Electrical and Computer Engineering

First Advisor

Demerdash, Nabeel A. O.

Second Advisor

Yaz, Edwin E.

Third Advisor

Ionel, Dan


Permanent magnet synchronous machines (PMSMs) have high efficiency, high power density, high torque-to-inertia ratio, and fast dynamic response. These features make this kind of machines very attractive for electric vehicle (EV) applications. However, because of their nature, i.e., constant magnet flux provided by magnets, these machines have a narrow constant power speed range (CPSR). This limitation is a strong drawback for application of PMSMs in electric vehicles, where high speed is the top requirement. Two different approaches can extend the maximum speed under constant power: (1) Increasing a drive's output voltage, and (2) implementing flux-weakening (FW) control methods. However, a conventional drive's output voltage is limited by its dc bus. Furthermore, FW control methods are constrained by the maximum output voltage of a drive. In this work, a new approach is demonstrated to obtain a wider CPSR range by implementing a Z-source inverter as a motor-drive. Such a Z-source inverter can provide highly boosted voltage and is immune to dead time and shoot through issues. In addition, in this thesis, a constant power FW control algorithm is developed and simulated for this new approach.