Control, Operating Limitations, and Stability Analysis for Single-Phase Quasi-Z Source Inverters With Reduced Capacitance

The inherent twice frequency ripple power (TFRP) in single-phase quasi-Z source inverters should be handled well to avoid its adverse effects. The existing solutions often require additional hardware devices, which increases costs and power losses inevitably, and even tightens operation constraints. This article proposes a control method to buffer the TFRP without any additional hardware. The operation principle analysis is provided in detail. The controller design and stability analysis based on the principle of time-scale separation and feedback linearization are presented. In addition, operating limitations of the inverter is found, which provides a guide for system design and normal operation. Experimental results verified the effectiveness of the proposed control method.