Impedance design of quasi-Z source network to limit double fundamental frequency voltage and current ripples in single-phase quasi-Z source inverter

This paper proposes an analytic model to calculate the double fundamental frequency (2ω) voltage and current ripples for single-phase quasi-Z-source inverter (qZSI). The model enables the exact calculation of the 2 Ω components of the inductor current and the capacitor voltage, which is crucial for designing a single-phase qZSI system. A guideline for selecting the capacitance and inductance in quasi-Z-source (qZS) network to limit both the dc-link voltage and input current 2ω ripples within a tolerable range is presented. Three cases are tested to verify the proposed analytic model and the design method by using simulation and experimental results. The identical analytic calculation result, the simulation result, and the experimental result validate the analytic model and the design method.