Seven-level cascade inverter with asymmetrical DC voltages

• Published in: IET power electronics Vol. 10; no. 1; pp. 112 - 119
• Main Authors: Wu, Kuen-Der, Jou, Hurng-Liahng, Wu, Jinn-Chang, Su, Jyun-Yi
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 20.01.2017
• Subjects: asymmetrical DC voltages; Asymmetry; Cascades; dc power source; dc‐dc converter; DDC; Electric potential; full‐bridge inverters; Hardware; hardware prototype; high‐voltage full‐bridge inverter; HVFB; Inverters; invertors; low‐voltage full‐bridge inverter; LVFB; power circuit; Power sources; seven‐level cascade inverter; SLCI; Switching; Voltage; seven-level cascade inverter; DDC; power circuit; dc-dc converter; LVFB; HVFB; dc power source; asymmetrical DC voltages; invertors; low-voltage full-bridge inverter; hardware prototype; SLCI; full-bridge inverters; high-voltage full-bridge inverter
• ISSN: 1755-4535; 1755-4543; 1755-4543
• DOI: 10.1049/iet-pel.2016.0293

This study proposes a novel seven-level cascade inverter (SLCI) with asymmetrical DC voltages. The proposed SLCI consists of two full-bridge inverters, a DC–DC converter (DDC) and a DC power source. The DC power source is parallel connected to the high-voltage full-bridge inverter (HVFB). The DDC is used to create a DC voltage with half of the DC power source and connect to the low-voltage full-bridge inverter (LVFB). The HVFB is switching at low frequency, and the LVFB is switching at high frequency. The salient points of the proposed SLCI are that only one DC power source is required and no transformer is used. Therefore, the power circuit for the proposed SLCI is simplified. A hardware prototype is established in order to verify the functions of the proposed SLCI. The tested results show that the functions of the proposed SLCI are as expected.