The conventional three-level active-neutral-point-clamped (ANPC) inverter requires high dc-link voltage at least twice the peak of ac output. To reduce the dc-link voltage, a recent topology that enhanced the voltage gain from half to unity has been presented. In this letter, an alternative ANPC topology is established by using two T-type inverters. Two floating capacitors with self-voltage balancing capability are integrated to achieve a voltage-boosting gain of 1.5. In addition, the proposed topology is capable of generating seven voltage levels. Its operation is validated through circuit analysis followed by experimental results of a prototype.
Manuscript received December 4, 2018; revised December 25, 2018; accepted January 3, 2019. Date of publication January 7, 2019; date of current version May 2, 2019. This work was supported in part by the Korea Institute of Energy Technology Evaluation and Planning, in part by the Ministry of Trade, Industry & Energy of the Republic of Korea under Grant 20171210201100, and in part by the Korea Foundation for Advanced Studies under International Scholar Exchange Fellowship. (Corresponding author: Kyo-Beum Lee.) S. S. Lee is with the University of Southampton Malaysia, Johor Bahru 79200, Malaysia, and also with the Power Electronics Laboratory, Ajou University, Suwon 16499, South Korea (e-mail:,szesinglee@gmail.com).
