Open AccessHighly efficient and reliable inverter concept‐based transformerless photovoltaic inverters with tri‐direction clamping cell for leakage current elimination
Author(s) -
Mei Ye,
Hu Senjun,
Lin Lei,
Li Wuhua,
He Xiangning,
Cao Fengwen
Publication year - 2016
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2015.0654
Subject(s) - inverter , photovoltaic system , total harmonic distortion , clamping , capacitor , leakage (economics) , electronic engineering , clamper , voltage , electrical engineering , computer science , topology (electrical circuits) , engineering , economics , computer vision , macroeconomics
Single‐phase transformerless inverters are widely employed in grid‐connected photovoltaic systems, because they are light, inexpensive and most importantly, have high conversion efficiencies. The highly efficient and reliable inverter concept (HERIC) is a well‐known topology for transformerless inverters. Theses inverters, however, suffer from high‐frequency leakage current generated by parasitic parameters. The mechanism behind the leakage current is described in this study. The concept of tri‐direction clamping cell (TDCC) applied to HERIC‐based transformerless inverters is proposed to eliminate the leakage current. This is achieved by clamping the freewheeling voltage to the midpoint voltage of the DC bus capacitors. A derived HERIC‐based inverter has been selected to be connected with a TDCC that is constructed from three active switches in Y‐type connection. This circuit is analysed in detail as an example in order to investigate the circuit performance. The experimental results show that the derived inverter has the advantages of leakage current elimination, high conversion efficiency and low grid current total harmonic distortion.