Asymmetric diode-clamped multi-level inverter based renewable power generation system

ABSTRACT

In this paper, a grid-connected power conversion topology is developed to convert a DC power from the renewable energy into a high-quality AC power. This grid-connected power conversion topology consists of an asymmetric diode-clamped multi-level inverter (DCT-MLI) and a dual-output DC-DC power converter. The asymmetric DCT-MLI includes two diode-clamped arms, two DC capacitors, and a filter inductor. The novelty of proposed asymmetric DCT-MLI is that the voltages of the two DC capacitors are in a multiple relationship. As a result, the asymmetric DCT-MLI will generate an AC voltage with more voltage levels by the power circuit similar to the symmetric DCT-MLI, and the capacity of filter inductor is further reduced. The dual-output DC-DC power converter combines a boost converter and a charge pump circuit to generate two DC voltages in a multiple relationship to supply the asymmetric DCT-MLI. The salient feature is that only a power electronic switch is used in the dual-output DC-DC power converter such that the control circuit is simplified. A hardware prototype is set up to verify the performances of the proposed grid-connected power conversion topology.

KEYWORDS:

• DC-DC power converter
• multi-level inverter
• renewable power generation system

Acknowledgments

The authors are grateful to the Ministry of Science and Technology of Taiwan for financial support for this paper under contract MOST 108-2221-E-992 −040.

Disclosure statement

No potential conflict of interest was reported by the authors.