Title :
DSP-based high precision current tracking control of gradient coil in two-paralleled PWM amplifiers for MRI systems
Author :
Watanabe, Shuji ; Boyagoda, Prasanna ; Fukuda, Hiroya ; Takano, Hiroshi ; Nakaoka, Mutsuo
Author_Institution :
Graduate Course of Eng. & Sci., Yamaguchi Univ., Japan
Abstract :
This paper presents a two-paralleled PWM amplifier using the switch-mode power current tracking technique in order to generate a gradient magnetic field in a 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 can 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; biomedical NMR; coils; insulated gate bipolar transistors; magnetic fields; power amplifiers; power bipolar transistors; power supplies to apparatus; switched mode power supplies; IGBTs; MRI power supply systems; PWM amplifier; control response; current ripple; current tracking control; diagnostic target; digital control scheme; gradient coil; gradient magnetic field; image quality; magnetic resonance imaging; power density; switch-mode power current tracking technique; Circuits; Coils; Digital control; Image quality; Magnetic fields; Magnetic resonance imaging; Magnetic switching; Power amplifiers; Power generation; Pulse width modulation;
Conference_Titel :
Power Electronics Specialists Conference, 1998. PESC 98 Record. 29th Annual IEEE
Conference_Location :
Fukuoka
Print_ISBN :
0-7803-4489-8
DOI :
10.1109/PESC.1998.702009
