Flux Based Technique to Identify the Location of Inter Turn Faults in Transformer
The internal turn-to-turn faults (TTFs), as a common cause of the transformer failures, result in minor changes on terminal currents/voltages. They maybe undetected by the conventional protective relays. In this study, a simple, sensitive and robust linkage flux based technique is proposed to protect the power transformers against TTFs. In this approach, some separated multi-turn windings as search coils (SCs) have to be wrapped around the transformer core legs to sense the related passing flux. Since passing equal flux through a transformer core leg in normal condition induces equal voltages in the related SCs, variation of the induced voltages indicates the fault occurrence in that phase. Against the traditional differential protection schemes, current transformer error and saturation, tap changer operation, energizing inrush current, over-fluxing etc. cannot impact the proposed technique performance. Therefore, it can be introduced as a comprehensive protection technique for power transformers. It is notable that not only the internal TTFs can be detected by the proposed technique but also other types of internal faults are diagnosable by this technique. For example, the Earth faults near the star point are detectable whenever the star connected winding is grounded solidly. Such faults are similar to TTFs near the star point, and then they are detectable by the proposed technique, as well.
The presented technique can discriminate the external faults from the internal ones, too. When an external fault occurs, transformer winding is shorted entirely. Therefore, the corresponding SCs measure the equal reduced linkage fluxes overall the faulty phase, and accordingly the ΣΔΕ on the faulty phase cannot be activated, as it should be. As a brief review, the ΣΔΕ can detect any event that creates a distortion in the flux symmetricity along each core leg. It senses only the flux uniformity along the core legs and reacts whenever this regularity is distorted.
The proposed technique can be used for all power transformers with different rating voltages and powers. Moreover, type of windings connections cannot impact the performance of the proposed technique, while it is demonstrated on the basis of the flux homogeneity in the healthy transformer core.
. Haghjoo, Farhad, Mohsen Mostafaei, and Mohsen Mohammadzadeh. "A novel flux-based protection scheme for power transformers." Power Systems Protection and Control Conference (PSPC), 2015 9th. IEEE, 2015.
. Gajić, Zoran, et al. "Sensitive turn-to-turn fault protection for power transformers." Joint Meetings of Cigré Study Committee B5 and IEEE Power System Relaying Committee, with the Study Committee B5 Colloquium. 2005.
. Babiy, Mariya, Rama Gokaraju, and Juan Carlos Garcia. "Turn-to-turn fault detection in transformers using negative sequence currents." Electrical Power and Energy Conference (EPEC), 2011 IEEE. IEEE, 2011.
. Jan, Shayan Tariq, Raheel Afzal, and Akif Zia Khan. "Transformer Failures, Causes & Impact." Civil and Mechanical Engineering. 2015.
. Kozadajevs J. Turn-to-Turn Fault Protection for Power Transformers. Summary of the Doctoral Thesis. – R.: RTU Press, 2015. – 50 p.
. Kumar, r. senthil, et al. "online internal fault identification in transformers based on direction and location of magnetizing signature patterns." Journal of Theoretical & Applied Information Technology 58.3 (2013).
. Kang, Y. C., et al. "A transformer protective relaying algorithm using the ratio of the flux linkages." Power Tech Conference Proceedings, 2003 IEEE Bologna. Vol. 2. IEEE, 2003.
To ensure uniformity of treatment among all contributors, other forms may not be substituted for this form, nor may any wording of the form be changed. This form is intended for original material submitted to AJCT and must accompany any such material in order to be published by AJCT. Please read the form carefully.
The undersigned hereby assigns to the Asian Journal of Convergence in Technology Issues ("AJCT") all rights under copyright that may exist in and to the above Work, any revised or expanded derivative works submitted to AJCT by the undersigned based on the Work, and any associated written, audio and/or visual presentations or other enhancements accompanying the Work. The undersigned hereby warrants that the Work is original and that he/she is the author of the Work; to the extent the Work incorporates text passages, figures, data or other material from the works of others, the undersigned has obtained any necessary permission. See Retained Rights, below.
AJCT distributes its technical publications throughout the world and wants to ensure that the material submitted to its publications is properly available to the readership of those publications. Authors must ensure that The Work is their own and is original. It is the responsibility of the authors, not AJCT, to determine whether disclosure of their material requires the prior consent of other parties and, if so, to obtain it.
RETAINED RIGHTS/TERMS AND CONDITIONS
1. Authors/employers retain all proprietary rights in any process, procedure, or article of manufacture described in the Work.
2. Authors/employers may reproduce or authorize others to reproduce The Work and for the author's personal use or for company or organizational use, provided that the source and any AJCT copyright notice are indicated, the copies are not used in any way that implies AJCT endorsement of a product or service of any employer, and the copies themselves are not offered for sale.
3. Authors/employers may make limited distribution of all or portions of the Work prior to publication if they inform AJCT in advance of the nature and extent of such limited distribution.
4. For all uses not covered by items 2 and 3, authors/employers must request permission from AJCT.
5. Although authors are permitted to re-use all or portions of the Work in other works, this does not include granting third-party requests for reprinting, republishing, or other types of re-use.
INFORMATION FOR AUTHORS
AJCT Copyright Ownership
It is the formal policy of AJCT to own the copyrights to all copyrightable material in its technical publications and to the individual contributions contained therein, in order to protect the interests of AJCT, its authors and their employers, and, at the same time, to facilitate the appropriate re-use of this material by others.
If you are employed and prepared the Work on a subject within the scope of your employment, the copyright in the Work belongs to your employer as a work-for-hire. In that case, AJCT assumes that when you sign this Form, you are authorized to do so by your employer and that your employer has consented to the transfer of copyright, to the representation and warranty of publication rights, and to all other terms and conditions of this Form. If such authorization and consent has not been given to you, an authorized representative of your employer should sign this Form as the Author.
AJCT requires that the consent of the first-named author and employer be sought as a condition to granting reprint or republication rights to others or for permitting use of a Work for promotion or marketing purposes.
1. The undersigned represents that he/she has the power and authority to make and execute this assignment.
2. The undersigned agrees to indemnify and hold harmless AJCT from any damage or expense that may arise in the event of a breach of any of the warranties set forth above.
3. In the event the above work is accepted and published by AJCT and consequently withdrawn by the author(s), the foregoing copyright transfer shall become null and void and all materials embodying the Work submitted to AJCT will be destroyed.
4. For jointly authored Works, all joint authors should sign, or one of the authors should sign as authorized agent
for the others.
Licenced by :