Designing of Autotransformer for 18-pulse Rectifier Unit

Abstract

It has been known that 6-pulse rectifiers and converters are the main sources of harmonics in electrical systems. Using multipulse rectifier is one of the harmonic mitigation methods for a system that contain 6-pulse rectifiers or converters. The multipulse rectifier that complies with the IEEE recommended practices and requirements for harmonic control in electrical power systems is the one that has 18 pulses or more. The main problem of the classical 18-pulse rectifier which uses zigzag transformer is its size and weight; however, this problem can be diminished by using an autotransformer. Though there are many literatures state the merit of the 18-pulse autotransformer rectifier systems, none of them presents an autotransformer design procedure. This paper demonstrates the design of an autotransformer for the 18-pulse rectifier system. The parameters obtained from the design have been implemented and the experimental results shown that the designed autotransformer is working well.