1. Three-level boost inverter with capacitor voltage self-balancing and high conversion efficiency for low DC voltage systems
- Author
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Hu, Bihua, Tang, Zhaohong, Zhang, Zhi, Linghu, Jinqing, Qian, Jihong, Qin, Xiangyun, Meng, Bumin, and Han, Rong
- Abstract
Currently, Z-source networks are widely employed to extend the output-voltage range of inverters operating at a low voltage DC source. However, these inverters are troubled by low power-conversion efficiency and an obvious current distortion due to the copper losses and core losses of the inductors. In addition, they have limited voltage levels. In this paper, a novel boost network composed of two power switches, two capacitors, and two diodes is proposed to overcome these shortcomings. Meanwhile, a corresponding modulation strategy is also set forth to achieve capacitor voltage self-balancing and to regulate the output AC voltage. Moreover, by adding more switched-capacitor cells, the range of the output voltage can be further improved, and the max DC/AC-voltage conversion ratio of the inverter withncells is √3(n+ 1)/3. At last, an inverter prototype with a 1 kW power rating is built, and the obtained results demonstrate that this inverter possesses the following superiorities: a wider range of output voltage, automatic balancing of the capacitor voltage, less current distortion, and high-efficiency power conversion.
- Published
- 2023
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