Current equalising transformer for current balance in parallel-connected 12-pulse converter

摘要

Current out-of-balance in 12-pulse rectifiers between two 6-pulse groups has caused serious problems. This has become particularly pronounced with semiconductor rectifiers where 12-pulse operation is obtained by two phase-displaced 3-phase bridge rectifier circuits operating in parallel. A current equalising transformer (CET) was introduced to overcome the problem. A new simpler variation of this has more been introduced, and the author describes this new variation.