Mitigation of triplen harmonics in 3-phase 4-wire electrical distribution system

• Main Author: Ahmad, Azhar
• Format: Thesis
• Language: English; English
• Published: 2007
• Subjects: T Technology (General); TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.utem.edu.my/id/eprint/14850/1/Mitigation%20of%20triplen%20harmonics%20in%203-phase%204-wire%20electrical%20distribution%20system%20-%20Copy.pdf; http://eprints.utem.edu.my/id/eprint/14850/2/Mitigation%20of%20triplen%20harmonics%20in%203-phase%204-wire%20electrical%20distribution%20system.pdf; http://eprints.utem.edu.my/id/eprint/14850/; https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=31817&query_desc=kw%2Cwrdl%3A%200000039893

This thesis addresses the mitigation of triplen harmonic distortion in 3-phase 4-wire electrical distribution system that supplies balanced and unbalanced non-linear loads. The main objectives of this thesis are to study, design and build passive mitigation devices suitable for mitigation of the triplen harmonic problems. There are four steps involved in building a harmonic mitigation device. Firstly, the requirements for the device basic mitigation technique and system installation are discussed. Second, the design parameters are calculated and determined to match the components. Third, the investigation is done using off the shelf and specially ordered components for the construction of mitigation device. The final step involves testing of these devices in laboratory environment. There are four selected passive mitigation devices built in this research. The devices are wye-zigzag transformer, neutral 3rd harmonic blocking series filter, 3-phase 3rd harmonic blocking series filter, and a 3-phase 3rd harmonic trap shunt filter. The performances of the various devices are compared. It is found that the wye-zigzag transformer is the most efficient device in reducing the triplen harmonic currents 'n 3-phase 4-wire electrical distribution system. In contrast the LC tuned 3-phase 3rd harmonic shunt filter generates its own harmonics and the LC tuned neutral 3rd harmonic series filter excessively raises the system neutral voltage. Meanwhile, the 3-phase 3rd harmonic blocking series filter performs well in reducing the triplen harmonic currents of single-phase loads. This thesis is a starting point towards a more detailed research in the development of more harmonic mitigation devices. Further investigation into the device's components characteristic such as material and construction of inductors, different types capacitor that influence the performance of mitigation device could be pursued. Finally, the development of an active filter based on DSP and power electronics would be a challenging future research in mitigating triplen and other harmonics in 3-phase 4-wire distribution system.