US 2017/0363698 A1 · A POWER DEVICE AND METHOD FOR DRIVING A LOAD

Abstract

Embodiments of the invention provide a power device. The power device comprises a switch mode power conversion circuit with power semiconductors for driving a load in response to a control signal, a controller coupled to the switch mode power conversion circuit to generate the control signal based on a predetermined current profile to be provided to the load and a maximum junction temperature of the power semiconductors, and a current injector coupled to the switch mode power conversion circuit and the controller for generating an offset current. The switch mode power conversion circuit is controlled to output the predetermined current profile or an adjusted current profile in response to the control signal, and the adjusted current profile has an offset with respect to the predetermined current profile. The offset current is equal to the offset between the adjusted current profile and the predetermined current profile and further summed with the adjusted current profile to generate the predetermined current profile to flow through the load if the control signal controls the switch mode power conversion circuit to output the adjusted current profile.

Claims15

Dependent claims

A power device for providing a load with a predetermined current profile, comprising:

a switch mode power conversion circuit including a plurality of power semiconductors for driving the load in response to a control signal;
a controller coupled to the switch mode power conversion circuit to generate the control signal based on the predetermined current profile and a maximum junction temperature of the power semiconductors, wherein the switch mode power conversion circuit is controlled to output the predetermined current profile or an adjusted current profile in response to the control signal, and wherein the adjusted current profile has an offset with respect to the predetermined current profile;
and
a current injector coupled to the controller for generating an offset current equal to the offset between the adjusted current profile and the predetermined current profile in response to the control signal, wherein the offset current and the adjusted current profile are summed to generate the predetermined current profile to flow through the load if the control signal controls the switch mode power conversion circuit to output the adjusted current profile.

1 more element

A method for operating a power semiconductor device to provide a load with a predetermined current profile, comprising:

generating a control signal based on the predetermined current profile and a maximum junction temperature of power semiconductors of a switch mode power conversion circuit in the power semiconductor device;
controlling the switch mode power conversion circuit to output the predetermined current profile or an adjusted current profile which has an offset with respect to the predetermined current profile in response to the control signal;
performing the following steps if the control signal controls the switch mode power conversion circuit to output the adjusted current profile,
generating an offset current equal to the offset between the adjusted current profile and the predetermined current profile;
and
summing the offset current with the adjusted current profile to generate the predetermined current profile to flow through the load.

3 more elements

A gradient amplifier system for driving a gradient coil in a magnetic resonance imaging device comprising:

a gradient amplifier including a plurality of the power semiconductors for outputting a gradient current;
a controller coupled to the gradient amplifier for controlling a current profile of the gradient current, wherein the controller determines the current profile of the gradient current to be a predetermined current profile or an adjusted current profile based on a maximum junction temperature of the semiconductor components, and wherein the adjusted current profile has an offset with respect to the predetermined current profile;
and
a current injector coupled to the gradient amplifier and the controller for generating an offset current equal to the offset between the adjusted current profile and the predetermined current profile, wherein the offset current and the adjusted current profile are summed to generate the predetermined current profile to flow through the gradient coil if the gradient amplifier outputs the gradient current with the adjusted current profile.

1 more element

Dependencies are inferred from the claim text.

A power device and method for driving a load

Life of this patent

A power device and method for driving a load

Life of this patent

Abstract

Claims15