Title :
A high precision power supply for magnets in magnetic resonance imaging systems: the “quadratic” power cell
Author :
Fazzi, A. ; Pirovano, C. ; Rotta, E. ; Varoli, V.
Author_Institution :
Dipartimento Ingeneria Nucl., Politecnico di Milano, Italy
Abstract :
The implementation of a high current, wide output range (both voltage 5-100 V and current 0.5-20 A) DC-to-DC power converter with 16-bit linearity is investigated. This power converter is intended to be the power supply for the coils of a multipolar magnet for a magnetic resonance imaging system. A mixed linear and switch-mode technique, i.e. the combination of a linear final regulator and a switching preregulator, makes it possible to achieve high accuracy and good efficiency. The reasons leading to the choice of a “quadratic” cell with a state-of-the-art switching frequency are discussed. Regulation characteristics, maximum stresses on the critical components, efficiency, stationary and dynamic behavior are evaluated by means of CAD tools and compared with the well-matched performances measured in a full power prototype
Keywords :
DC-DC power convertors; coils; electromagnets; magnetic resonance; power supplies to apparatus; switched mode power supplies; switching circuits; voltage regulators; 0.5 to 20 A; 16 bit; 5 to 100 V; DC-to-DC power converter; accuracy; efficiency; linear final regulator; linear/switch-mode technique; magnetic resonance imaging; multipolar magnet power supply; quadratic power cell; state-of-the-art; switching frequency; switching preregulator; Coils; DC-DC power converters; Linearity; Magnetic resonance; Magnetic resonance imaging; Magnets; Power supplies; Regulators; Switching frequency; Voltage;
Conference_Titel :
Power Electronics Specialists Conference, 1995. PESC '95 Record., 26th Annual IEEE
Conference_Location :
Atlanta, GA
Print_ISBN :
0-7803-2730-6
DOI :
10.1109/PESC.1995.474800
