公开(公告)号：US09551767B2

公开(公告)日：2017-01-24

申请号：US13709812

申请日：2012-12-10

Applicant: General Electric Company

Inventor： Juan Antonio Sabate ,  Wesley Michael Skeffington ,  Song Chi ,  Rixin Lai ,  Yimeng Shi ,  Yanjun Zhang

IPC: G01V3/00 ,  G01R33/36 ,  G01R33/54 ,  G01R33/385

CPC classification number: G01R33/3614 ,  G01R33/3852 ,  G01R33/543

Abstract: A gradient amplifier system, includes: a power stage comprising a plurality of bridge amplifiers, each operates at a first switching frequency; a gradient coil coupled to the power stage and configured to produce a magnetic field proportional to a coil current signal supplied by the power stage; a controller stage coupled to an input terminal of the power stage and configured to: generate a pulse width modulated gate signal based on the coil current signal and a reference current signal, wherein the pulse width modulated gate signal is generated at a second switching frequency when a slew rate associated with the reference current signal is below a threshold rate for at least a first time period; and apply the pulse width modulated gate signal to the power stage for changing an operating frequency of each of the plurality of bridge amplifiers from the first to the second switching frequency.

Abstract translation: 一种梯度放大器系统，包括：功率级，包括多个桥式放大器，每个以第一开关频率工作; 耦合到功率级并被配置为产生与由功率级提供的线圈电流信号成比例的磁场的梯度线圈; 控制级，其耦合到所述功率级的输入端，并且被配置为：基于所述线圈电流信号和参考电流信号产生脉宽调制门信号，其中所述脉宽调制门信号以第二开关频率产生， 与参考电流信号相关联的转换速率低于至少第一时间段的阈值速率; 并且将所述脉冲宽度调制的栅极信号施加到所述功率级，以将所述多个桥接放大器中的每一个的工作频率从第一开关频率改变为第二开关频率。

公开(公告)号：US20130162250A1

公开(公告)日：2013-06-27

申请号：US13709812

申请日：2012-12-10

Applicant: General Electric Company

Inventor： Juan Antonio Sabate ,  Wesley Michael Skeffington ,  Song Chi ,  Rixin Lai ,  Yimeng Shi ,  Yanjun Zhang

IPC: G01R33/36 ,  G01R33/54

CPC classification number: G01R33/3614 ,  G01R33/3852 ,  G01R33/543

Abstract: A gradient amplifier system, includes: a power stage comprising a plurality of bridge amplifiers, each operates at a first switching frequency; a gradient coil coupled to the power stage and configured to produce a magnetic field proportional to a coil current signal supplied by the power stage; a controller stage coupled to an input terminal of the power stage and configured to: generate a pulse width modulated gate signal based on the coil current signal and a reference current signal, wherein the pulse width modulated gate signal is generated at a second switching frequency when a slew rate associated with the reference current signal is below a threshold rate for at least a first time period; and apply the pulse width modulated gate signal to the power stage for changing an operating frequency of each of the plurality of bridge amplifiers from the first to the second switching frequency.

Abstract translation: 一种梯度放大器系统，包括：功率级，包括多个桥式放大器，每个以第一开关频率工作; 耦合到功率级并被配置为产生与由功率级提供的线圈电流信号成比例的磁场的梯度线圈; 控制级，其耦合到所述功率级的输入端，并且被配置为：基于所述线圈电流信号和参考电流信号产生脉宽调制门信号，其中所述脉宽调制门信号以第二开关频率产生， 与参考电流信号相关联的转换速率低于至少第一时间段的阈值速率; 并且将所述脉冲宽度调制的栅极信号施加到所述功率级，以将所述多个桥接放大器中的每一个的工作频率从第一开关频率改变为第二开关频率。