Title :
Power conversion PWM amplifier with two paralleled four quadrant chopper for MRI gradient coil magnetic field current tracking implementation
Author :
Watanabe, Shuji ; Boyagoda, Prasanna ; Iwamoto, Hideo ; Nakaoka, Mutsuo ; Takano, Hiroshi
Author_Institution :
Graduate Sch. of Sci. & Eng., Yamaguchi Univ., Japan
Abstract :
This paper presents a two-paralleled PWM amplifier using switch-mode power current tracking technique in order to generate a gradient magnetic field in the magnetic resonance imaging (MRI) system. This circuit has 8-IGBTs at their inputs/outputs so as to realize further high-power density. A digital control scheme is adopted to minimize the current ripple and improve its control response in the gradient coils (GCs). It is proved that the proposed technique will highly enlarge the diagnostic target and improve the image quality of MRI
Keywords :
PWM power convertors; amplifiers; choppers (circuits); coils; digital control; electric current control; insulated gate bipolar transistors; magnetic resonance imaging; switched mode power supplies; IGBT; MRI gradient coil magnetic field current tracking; control response; current ripple minimisation; diagnostic target enlargement; digital control scheme; gradient magnetic field generation; high-power density; image quality improvement; inputs/outputs; magnetic resonance imaging system; power conversion PWM amplifier; switch-mode power current tracking; two paralleled four quadrant chopper; Circuits; Coils; Digital control; Magnetic fields; Magnetic resonance imaging; Magnetic switching; Power amplifiers; Power conversion; Power generation; Pulse width modulation;
Conference_Titel :
Power Electronics Specialists Conference, 1999. PESC 99. 30th Annual IEEE
Conference_Location :
Charleston, SC
Print_ISBN :
0-7803-5421-4
DOI :
10.1109/PESC.1999.785619
