Date of Award

December 2012

Degree Type


Degree Name

Master of Science



First Advisor

Adel Nasiri

Committee Members

Helge Klockow, Ramin Pashaie, Tesfaye Kidane


Medical, PDU, Power Electronics


The focus of this thesis is to design, model, build, and test a series resonance converter that uses a high frequency isolation transformer, offering significant reduction in size and cost, for powering a Computed Tomography (CT) scanner. The design increases the power quality for the load by isolating the grid side disturbances, and providing regulated desired voltage. The proposed architecture also allows for an optimized point of integration with an UPS, a regulated DC bus to improve waveform fidelity of x-ray generator, and active monitoring and control of the power architecture. Conventional CT systems use a 60Hz transformer, which not only occupies large footprints but also uses large amounts of copper and iron with increasing cost trajectory. In comparison to the traditional Power Distribution Units (PDU), the medical grade high frequency PDU presented in this thesis provides higher power quality and performance at a lower cost.

The new CT systems possess unprecedented performance capability in terms of rotational speed and x-ray voltage modulation ("Ultra-Fast kV") fidelity. In order to achieve such capabilities, a tightly regulated high power DC bus (700VDC, 150kW) is required. The system implemented in this thesis satisfies these new requirements. Design requirements, proposed architecture and controls, modeling, implementation and test results of the proposed system, including thermal analysis and electromagnetic compatibility, are presented in details in this thesis.