Double-Line-Frequency Ripple Model, Analysis, and Impedance Design for Energy-Stored Single-Phase Quasi-Z-Source Photovoltaic System
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1982-2012 IEEE. The battery energy-stored quasi-Z-source (BES-qZS)-based photovoltaic (PV) power generation system combines advantages of the qZS inverter and the battery energy storage system. However, the second-harmonic (2) power ripple degrades the system's performance and affects the system's design. An accurate model to analyze the 2 ripple is very important. The existing models did not consider the battery, or assumed a symmetric qZS network with L-1= L-2 and C-1= C-2, which limits the design freedom and causes oversized impedance parameters. This paper proposes a comprehensive model for the single-phase BES-qZS-PV inverter system, where the battery is considered and there is no restriction of L-1= L-2 and C-1= C-2. Based on the built model, a BES-qZS impedance design method is proposed to mitigate the 2 ripple with asymmetric qZS network. Simulation and experimental results verify the proposed 2 ripple model and impedance design method.