Simulation of Source Current Harmonic Elimination Technique Using Phase Shifting Transformer
I Made Wiwit Kastawan, Erwin Yusuf, Afif Fadhilah
Department of Energy Conversion Engineering, Politeknik Negeri Bandung
Jl. Gegerkalong Hilir, Bandung Barat, Jawa Barat, Indonesia
E-mail: wiwit.kastawan[at]polban.ac.id, erwin.yusuf[at]gmail.com, afiffadhilah.erg[at]gmail.com
Abstract
This paper presents a detailed description about design of phase shifting transformer to reduce source current harmonic generated by variable speed drive (VSD) units commonly used for controlling speed of hot air blower motors of a stenter machine in textile industry. Nine units of VSD are used in a stenter machine of a selected textile industry that generates source current with relatively high harmonic content. Total harmonic distortion (THD) figure of the source current varies from 43.91% to 50.34%. The source current contains all odd order harmonics except triplen ones. A method proposed to reduce this source current harmonic is by using phase shifting transformer. Two different phase shifting transformer arrangements are possible. The first one is arrangement of three phase shifting transformers. The other one is arrangement of nine phase shifting transformers. Arrangement of three phase shifting transformers uses Yy, Yz1 and Yz2 three-phase winding connection to produce phase shifting of 0, 20 and –20 respectively. Meanwhile, arrangement of nine phase shifting transformers uses one Yy three-phase winding connection with 0 phase shifting, four Yz1 three-phase winding connections with 6.67, 13.34, 20 and 26.67 phase shifting respectively and four Yz2 three-phase winding connections with –6.67, –13.34, –20 and –26.67 phase shifting respectively. Results from simulation using MATHLAB SIMULINK show that harmonic content of the source current reduced significantly. THDs of the source current drop to 1.99% and 1.74% respectively when arrangements of three phase shifting transformers and nine phase shifting transformers are used.
Keywords: current harmonic, phase shifting, three-phase transformer, THD, VSD.
Topic: Electrical Engineering