Three-Phase Split Delta-Source Inverter: Operating Principles and Modulation

摘要

Three winding coupled inductors have been widely used in impedance-source inverters, such as Y-source inverters and delta-source inverters. They can improve the boosting capability of the inverter without adding active switches. However, their boosting coefficients decrease with the increase of the modulation, which will cause the voltage quality and utilization of the DC bus to be greatly reduced under high-voltage gain. Besides, non-negligible leakage inductance exists in this type of impedance source inverter, which will cause a sudden change in the induced current in the impedance source network and produce a larger voltage spike. So it is necessary to introduce buffer or absorption circuits. In order to overcome these limitations, this paper proposes a split $Delta$-source inverter. Its boosting capability increases with the increase of the modulation. At the same time, there is no voltage spike under the existence of non-negligible leakage inductance and no absorb-circuit. This paper verifies the performance of the inverter from three aspects: theoretical analysis, simulation, and experimental results.