General Electric Company

Yimeng Shi

Juan Antonio Sabate

Tao Ma

Garron Koch Morris

Xi Lu

Pengcheng Zhu

Wesley Michael Skeffington

Jeffrey Neal Slotnick

Margaret Ann Wiza

Fei Xu

Rixin Lai

Song Chi

Xinhui Wu

Yanjun Zhang

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.

System and method to reduce power loss in a gradient amplifier

A resonant power supply is disclosed. The resonant power supply includes a series resonant configured to convert an input DC voltage to an output DC voltage. The resonant power supply further comprises a converter controller coupled to the series resonant converter and configured to receive a DC voltage feedback signal measured at the output of the series resonant converter, or a resonant current feedback signal representing a resonant current flowing through the series resonant converter. The converter controller is further configured to generate control signals to be applied to the series resonant converter to limit the output DC voltage of the series resonant converter according to the DC voltage feedback signal and a predetermined voltage threshold signal, or to limit the resonant current of the series resonant converter according to the resonant current feedback signal and a predetermined current threshold signal.

System and method for series resonant converter protection

A gradient amplifier for driving a gradient coil is disclosed. The gradient amplifier includes a direct current (DC) bus for receiving DC voltage generated from a series resonant converter, an inverter coupled to the DC bus configured to receive the DC voltage at the DC bus and convert the DC voltage to generate an output voltage to be applied to the gradient coil, and an inverter controller coupled to the inverter. The inverter controller is configured to generate control signals to control operation of the inverter based at least on a DC voltage feedback signal measured at the DC bus, an output voltage feedback signal measured at the output of the inverter, and a reference output voltage signal indicative of a desired voltage to be achieved at the output of the inverter.

System and method for gradient amplifier control

A resonant power supply is provided. The resonant power supply comprises a series resonant converter configured to convert an input DC voltage to an output DC voltage to generate an output DC voltage. The series resonant converter includes a switching stage, a resonant inductor, a resonant capacitor, and an isolation transformer. The resonant power supply further comprises a converter controller configured to obtain an actual trajectory radius signal based on a resonant inductor current, a resonant capacitor voltage, and a voltage in association with the isolation transformer. The converter controller is further configured to generate a trajectory radius command signal based on a DC voltage command signal and a DC voltage feedback signal, and to generate control signals to be applied to the switching stage based on the actual trajectory radius signal and the trajectory radius command signal.

System and method for power supply control

Growing community of inventors

Hangzhou, China

Yimeng Shi