Multi-inverter drive with symmetrical multilevel winding voltage of transformer during overmodulation

Abstract

Modified techniques and algorithms of space-vector pulsewidth modulation (PWM), assuring symmetrical voltage waveforms of voltage source inverters, have been disseminated for overmodulation adjustment of three inverters of transformer-based installation with new interconnection between converters and the inverter-side windings of power transformer. Simulation results show, that novel connection between convertors and windings of power transformer assures an advanced spectra of inverter-side winding voltages in comparison with standard interconnection between converters and windings of power transformer in the overmodulation zone. Advanced harmonic spectra of winding voltages of the analyzed system insure to decrease the copper losses in the corresponding windings of power transformer during overmodulation control.