Effects of firing angle imbalance on 12-pulse rectifiers with interphase transformers

Firing angle or source imbalances between 6-pulse bridges comprising a 12-pulse rectifier lead to current imbalance, due to the finite magnetizing inductance of the interphase transformer. The magnitude of the imbalance is limited by the negative feedback produced by load regulation of the 6-pulse g...

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Bibliographic Details
Main Authors: Perreault, David J., Kassakian, John G.
Other Authors: Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Format: Article
Language:en_US
Published: Institute of Electrical and Electronics Engineers (IEEE) 2014
Online Access:http://hdl.handle.net/1721.1/86988
https://orcid.org/0000-0002-0746-6191
https://orcid.org/0000-0002-3443-5702
Description
Summary:Firing angle or source imbalances between 6-pulse bridges comprising a 12-pulse rectifier lead to current imbalance, due to the finite magnetizing inductance of the interphase transformer. The magnitude of the imbalance is limited by the negative feedback produced by load regulation of the 6-pulse groups. This paper uses both an averaged model and a piecewise-linear simulation to obtain a quantitative understanding of this effect. The averaged model is used to predict steady-state current shifts and transient behavior. The piecewise-linear model of the system is then used to verify and extend the results via computer simulation. It is shown that the current imbalance can be accurately predicted by the averaged model, making the model suitable for both feedback control and interphase transformer design.