*Article* **DC-DC High-Voltage-Gain Converters with Low Count of Switches and Common Ground**

#### **Robert Stala, Zbigniew Waradzyn \* and Szymon Folmer**

Department of Power Electronics and Energy Control Systems, Faculty of Electrical Engineering, Automatics, Computer Science and Biomedical Engineering, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow, Poland; stala@agh.edu.pl (R.S.); folmer@agh.edu.pl (S.F.) **\*** Correspondence: waradzyn@agh.edu.pl; Tel.: +48-12-617-2811

Received: 1 September 2020; Accepted: 26 October 2020; Published: 29 October 2020

**Abstract:** This paper presents a new concept and research results of DC-DC high-voltage-gain, high-frequency step-up resonant converters. The proposed topologies are optimized towards minimizing the number of switches and improvements in efficiency. Another relevant advantage of such type of converters is that they have a common input and output negative point. The proposed converters are based on the resonant switched-capacitor voltage multiplier circuit, and that is why they are compared with a classic converter from this family. The included results show the operating principle, possible switching methods with the consideration of their impact on the voltage gain level, as well as the voltage and current ripples. The operating concepts and analytical calculations are confirmed by simulation and experimental results.

**Keywords:** DC-DC converter; resonant converter; high-voltage-gain converter; switched-capacitor converter; inductiveless converter
