A Variable-DC-Offset Modulation Scheme for Improved Performance of a Differential-Mode Inverter

In this article, a novel continuous modulation scheme with variable-dc-offset (CMS-VDO) is proposed for a single-phase differential-mode inverter (DMI). The output voltage of the DMI is the difference in output voltages of two differentially connected dc-dc converters. CMS-VDO is so designed that the output voltage of the individual dc/dc converter is reduced without affecting the output voltage of the DMI. This reduced voltage yields reductions in circulating current, peak switch voltage, total harmonic distortion, and improved efficiency compared to conventional modulation scheme with fixed dc offset (CMS-FDO). The experimental results compare and validate the improved inverter performance using CMS-VDO over CMS-FDO.