Overmodulation Operation of Two-Level PWM Inverters of Photovoltaic System with Double-Delta Configuration of Winding of Power Transformer

This paper presents results of investigation of operation (in the overmodulation control zone) of two three-phase inverters of photovoltaic installation with double-delta-sourced winding of power transformer. It has been shown, that schemes and algorithms of synchronous multi-zone pulsewidth modulation (PWM), developed and modified for synchronous adjustment of inverters of photovoltaic system in the zone of overmodulation, insure synchronization, symmetry, and improved spectral composition of both output voltage of inverters and the corresponding winding voltages of multi-winding power transformer.