Differential protection improvement of power transformers using wavelet analysis of power system frequency

Author

Abniki, H. ; Monsef, H. ; Nabavi-Razavi, M.T. ; Gardeshi, M. Ebrahimi

Author_Institution

ECE Sch., Univ. of Tehran, Tehran, Iran

fYear

2011

fDate

25-28 Sept. 2011

Firstpage

1

Lastpage

6

Abstract

This paper presents a new technique for inrush current detection of power transformers. The method is based on wavelet analysis of power system frequency which is estimated by Prony method. The Prony method is utilized to estimate power system frequency with three consecutive samples rapidly. After that, Daubechies wavelet family uses the estimated frequency to investigate the unbalanced conditions in power system. Meanwhile, a new time based criterion is introduced to determine internal fault currents from inrush currents by using the changes of estimated power system frequency. Extended simulations for various faults and inrush conditions demonstrate precise operation of the proposed algorithm also in CT saturation.

Keywords

frequency estimation; transformer protection; wavelet transforms; CT saturation; Daubechies wavelet family; Prony method; differential protection improvement; inrush current detection; inrush currents; internal fault currents; power system frequency estimation; power transformers; wavelet analysis; Circuit faults; Current transformers; Fault currents; Frequency estimation; Power transformers; Surge protection; Surges; Power transformer protection; Prony method; frequency estimation; inrush current; internal fault; wavelet transform;

fLanguage

English

Publisher

ieee

Conference_Titel

Intelligent System Application to Power Systems (ISAP), 2011 16th International Conference on

Conference_Location

Hersonissos

Print_ISBN

978-1-4577-0807-7

Electronic_ISBN

978-1-4577-0808-4

Type

conf

DOI

10.1109/ISAP.2011.6082203

Filename

6082203