Modeling and Implementation of Active-Harmonic-Elimination Switched-Capacitor Boost DC-AC Inverter

The modeling and implementation of a 9-level switched-capacitor (SC) boost DC-AC inverter is presented by combining an active-harmonic-elimination (AHE) controller for realizing a staircase inversion and closed-loop regulation. In this 9-level SC inverter, there are three pumping capacitors and bidirectional switches used between supply VS and output Vout in order to obtain the maximum gain of 4 as well as the inverted gain of 4 at most. For achieving a staircase AC output, these bidirectional switches are driven by the clock generator so as to boost/invert Vout into 1x, 2x, 3x, or 4x voltage of VS. Here, the AHE technique is employed not only to manipulate the time durations of the output levels of 1x, 2x, 3x, 4x for the elimination of the 3rd, 5th, 7th harmonics, but also to enhance the regulation capability for the different desired output. Further, the relevant modeling and some theoretical analysis are included. The performance of this inverter is simulated and verified experimentally on the implemented prototype circuit to show the efficacy of this scheme.