Abstract
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.
Original language | English |
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Journal | IET Power Electronics |
Volume | 8 |
Issue number | 7 |
Pages (from-to) | 1273-1283 |
Number of pages | 11 |
ISSN | 1755-4535 |
DOIs | |
Publication status | Published - Jul 2015 |
Keywords
- Parallel inverters
- parallel interleaved inverters
- parallel interleaved converters
- Modulation scheme
- Phase-shifted carrier-based pulsewidth modulation (PSC-PWM)
- circulating current
- circulating current suppression
- common mode circulating current
- circulating current control
- Circulating Current