**Experimental Comparison of Two-Level Full-SiC and Three-Level Si–SiC Quasi-Z-Source Inverters for PV Applications**

**Serhii Stepenko 1,2,\*, Oleksandr Husev 1,3, Dmitri Vinnikov 1, Carlos Roncero-Clemente 4, Sergio Pires Pimentel 1,5 and Elena Santasheva 1,4**


Received: 6 June 2019; Accepted: 25 June 2019; Published: 28 June 2019

**Abstract:** The paper presents a comparative study of two solar string inverters based on the Quasi-Z-Source (QZS) network. The first solution comprises a full-SiC two-level QZS inverter, while the second design was built based on a three-level neutral-point-clamped QZS inverter with Silicon based Metal–Oxide–Semiconductor Field-E ffect Transistors (Si MOSFETs). Several criteria were taken into consideration: the size of passive elements, thermal design and size of heatsinks, voltage stress across semiconductors, and e fficiency investigation. The Photovoltaic (PV)-string rated at 1.8 kW power was selected as a case study system. The advantages and drawbacks of both solutions are presented along with conclusions.

**Keywords:** DC–AC converters; e fficiency; neutral-point-clamped inverter; PV applications; PV inverters; PV systems; quasi-z-source; two-level inverter; three-level inverter; converter topologies
