Fraction Phase Lead Repetitive Control and its Application in Inverter

In order to reduce turn-off losses, the switching frequency of power devices, which is sampling rate, is usually chosen to be low in high power inverter application. Limited by the digital sampling, phase lead step should be integer, in which case the repetitive control tends to be unstable under low sampling application. Thus fractional phase lead repetitive control is proposed. This method enables the phase lead step can be fractional, thus enlarges the stability region and improves the tracking accuracy as well. The detailed parameters design is given. At last, simulations of inverter using fractional phase lead repetitive control are presented. The results verify that fractional phase lead repetitive control favors better stability and harmonic suppression.Copyright © 2015 by ASME