Sunpower Corporation

Enphase Energy, Inc.

Hengsi Qin

Patrick L Chapman

Fernando Rodriguez

Jonathan Ehlmann

Gabor Banfi

An inverter includes a transformer that includes a first winding, a second winding, and a third winding, a DC-AC inverter electrically coupled to the first winding of the transformer, a cycloconverter electrically coupled to the second winding of the transformer, an active filter electrically coupled to the third winding of the transformer. The DC-AC inverter is adapted to convert the input DC waveform to an AC waveform delivered to the transformer at the first winding. The cycloconverter is adapted to convert an AC waveform received at the second winding of the transformer to the output AC waveform having a grid frequency of the AC grid. The active filter is adapted to sink and source power with one or more energy storage devices based on a mismatch in power between the DC source and the AC grid.

Converter topologies and control

Inverter circuit operation for managing power factor changes is provided. Various modes of switch timing may be employed near zero-voltage crossings. Inverter switch timing may change during a cycle such that one timing strategy is employed approaching or leaving a zero-voltage crossing while another timing strategy is employed at other times of the cycle.

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Austin, TX, United States of America

Hengsi Qin