Open AccessAnalysis and modelling of circulating current in two parallel‐connected inverters
Author(s) -
Maheshwari Ramkrishan,
Gohil Ghanshyamsinh,
Bede Lorand,
MunkNielsen Stig
Publication year - 2015
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.2014.0656
Subject(s) - pulse width modulation , total harmonic distortion , root mean square , current (fluid) , control theory (sociology) , power (physics) , harmonic , voltage , harmonic analysis , filter (signal processing) , distortion (music) , modulation (music) , computer science , electronic engineering , physics , engineering , electrical engineering , acoustics , amplifier , control (management) , cmos , quantum mechanics , artificial intelligence
Parallel‐connected inverters are gaining attention for high power applications because of the limited power handling capability of the power modules. Moreover, the parallel‐connected inverters may have low total harmonic distortion of the ac current if they are operated with the interleaved pulse‐width modulation (PWM). However, the interleaved PWM causes a circulating current between the inverters, which in turn causes additional losses. A model describing the dynamics of the circulating current is presented in this study which shows that the circulating current depends on the common‐mode voltage. Using this model, the circulating current between two parallel‐connected inverters is analysed in this study. The peak and root mean square (rms) values of the normalised circulating current are calculated for different PWM methods, which makes this analysis a valuable tool to design a filter for the circulating current. The peak and rms values of the circulating current are plotted for different PWM methods, and a discontinuous PWM is identified which offers the minimum peak and rms value of the circulating current. Experimental results are presented to verify the analysis.