201. A Modulation Method for Leakage Current Reduction in a Three-Phase Grid-Tie Quasi-Z-Source Inverter.
- Author
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Noroozi, Negar, Yaghoubi, Mokhtar, and Zolghadri, Mohammad Reza
- Subjects
- *
ELECTRIC inverters , *LEAKAGE , *FOURIER analysis , *VECTOR spaces , *ELECTROMAGNETIC interference , *FOURIER transforms - Abstract
The leakage current originated from the fluctuations of the common-mode voltage (CMV) is an issue in a transformerless grid-connected photovoltaic system. In this paper, a modified space vector modulation based on the Fourier transform analysis is proposed to reduce the leakage current in a three-phase quasi-Z-source inverter (qZSI). The CMV harmonic content in a qZSI contains low- and high-frequency harmonics that cause safety and electromagnetic interference problems, respectively. By implementing the proposed modulation in a three-phase qZSI, the low-frequency harmonics of the CMV are mainly reduced. The distribution of the high-frequency harmonics is also modified in a way they can be simply filtered. Passive filtering in a qZSI using other modulation techniques is less effective than using this method. Applying the proposed modulation in the presence of a high-frequency inductive-capacitive filter results in the strong suppression of both high- and low-frequency harmonics (more than 90% in the investigated case). A reduced-voltage prototype is designed to evaluate the modulation method. The experimental results from this prototype verify the accuracy of the proposed technique. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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