A Nine-Level Grid-Connected Converter Topology for Single-Phase Transformerless PV Systems

作者：Buticchi Giampaolo^*; Barater Davide; Lorenzani Emilio; Concari Carlo; Franceschini Giovanni

来源：IEEE Transactions on Industrial Electronics, 2014, 61(8): 3951-3960.

DOI：10.1109/TIE.2013.2286562

• Leakage current
• multilevel systems
• photovoltaic (PV) systems
• pulsewidth modulation (PWM) inverters

This paper presents a single-phase transformerless grid-connected photovoltaic converter based on two cascaded full bridges with different dc-link voltages. The converter can synthesize up to nine voltage levels with a single dc bus, since one of the full bridges is supplied by a flying capacitor. The multilevel output reduces harmonic distortion and electromagnetic interference. A suitable switching strategy is employed to regulate the flying-capacitor voltage, improve the efficiency (most devices switch at the grid frequency), and minimize the common-mode leakage current with the help of a novel dedicated circuit (transient circuit). Simulations and experiments confirm the feasibility and good performance of the proposed converter.

• 出版日期2014-8