Multilevel converter with cells being selected based on phase arm current

摘要

A method and computer program product are provided for selecting switching cells for voltage contribution in a phase arm of a multilevel converter, a cell selecting control device for a multilevel converter and a multilevel converter. The cell selecting control device and multilevel converter includes a balancing control element that obtains a reference voltage for the phase arm, obtains a measurement of the current running through the phase arm and selects cells for contributing to an AC voltage output from the multilevel converter based on the reference voltage and the magnitude of the phase arm current.

主权项

1. A method of selecting switching cells for voltage contribution in a phase arm of a multilevel converter operating to convert between alternating current and direct current, the method being performed by a voltage balancing element of the converter and comprising: organizing, triggered by a current zero crossing of a phase arm current, the cells for limiting switching at high phase arm current levels; and selecting cells for contributing to an AC voltage output from the multilevel converter based on a reference voltage of the phase arm and the magnitude of the phase arm current.