METHOD FOR CONTROLLING THE VOLTAGE BALANCE OF THE CAPACITORS OF THE DC BUS IN MULTILEVEL POWER CONVERTERS

摘要

Method for controlling the voltage balance of the capacitors of the DC bus in multilevel power converters, which method is based on the time-division switching of the gamma component of the averaged control signal of the switches in the converter and is characterized by the division of the sampling period of the voltage differences of the capacitors into two subintervals in which the gamma component adopts a particular constant value in each of said subintervals, with the constant application values being selected from a table containing pairs of predetermined control values, according to the signs of the voltage differences; wherein the criterion for selecting these constant values is determined by the effect produced by the values on the net variations of the voltage differences of the capacitors throughout a sampling period, giving rise to a series of regions in the value space of the control signal.