System and method for power supply control

A method of operating a series resonant converter, the method comprising:

• obtaining an actual trajectory radius signal based on a resonant inductor current measured at a resonant inductor of the series resonant converter, a resonant capacitor voltage measured at a resonant capacitor of the series resonant converter, and a voltage measured in association with an isolation transformer of the series resonant converter;
• generating a trajectory radius command signal based on a DC voltage command signal indicative of a desired DC voltage to be achieved at the output of the series resonant converter and a DC voltage feedback signal measured at the output of the series resonant converter;
• and
• generating control signals to be applied to a switching stage of the series resonant converter based on the obtained actual trajectory radius signal and the trajectory radius command signal.

A magnetic resonance system, comprising:

• a main magnet for generating a main magnetic field;
• a gradient coil for applying gradient magnetic field to the main magnetic field along selected gradient axes;
• a gradient amplifier coupled to the gradient coil for driving the gradient coil;
• a series resonant converter coupled to the gradient amplifier for supplying power to the gradient amplifier, wherein the series resonant converter is configured to convert an input direct current (DC) voltage to generate an output DC voltage, the series resonant converter comprising a switching stage, a resonant inductor, a resonant capacitor, and an isolation transformer;
• and
• a converter controller coupled to the series resonant converter, wherein the converter controller is configured to:
• obtain an actual trajectory radius signal based on a resonant inductor current measured at the resonant inductor, a resonant capacitor voltage measured at the resonant capacitor, and a voltage measured in association with the isolation transformer;
• generate a trajectory radius command signal based on a DC voltage command signal indicative of a desired DC voltage to be achieved at the output of the series resonant converter and a DC voltage feedback signal measured at the output of the series resonant converter;
• and
• generate control signals to be applied to the switching stage of the series resonant converter based on the actual trajectory radius signal and the trajectory radius command signal.