Topology Review of Three-Phase Two-Level Transformerless Photovoltaic Inverters for Common-Mode Voltage Reduction

In grid-connected photovoltaic (PV) systems, a transformer is needed to achieve the galvanic isolation and voltage ratio transformations. Nevertheless, these traditional configurations of transformers increase the weight, size, and cost of the inverter while decreasing the efficiency and power densi...

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Bibliographic Details
Main Authors: Truong-Duy Duong, Minh-Khai Nguyen, Tan-Tai Tran, Dai-Van Vo, Young-Cheol Lim, Joon-Ho Choi
Format: Article
Language:English
Published: MDPI AG 2022-04-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/15/9/3106
Description
Summary:In grid-connected photovoltaic (PV) systems, a transformer is needed to achieve the galvanic isolation and voltage ratio transformations. Nevertheless, these traditional configurations of transformers increase the weight, size, and cost of the inverter while decreasing the efficiency and power density. The transformerless topologies have become a good solution. However, the problem is that commode-mode voltage and leakage current can occur via the stray capacitors between the PV array and the ground of the inverter. Various transformerless inverters have been introduced with different techniques, such as reducing the common-mode voltage or eliminating the leakage current. Furthermore, to introduce the development of transformerless PV inverters, especially in three-phase two-level inverter systems, this paper provides a comprehensive review of various common-mode voltage reduction three-phase two-level inverters.
ISSN:1996-1073