REMOVAL OF DECAYING DC OFFSET FROM FAULT CURRENT BY USING KALMAN FILTERING THEORY

  HOMENDRA KUMAR,  ROSHNI RAHNAGDALE

this thesis describes the implementation of Kalman filtering theory for removal of decaying DC offset from fault current. This is a process by which a DC offset can be removed from fault current and can be recovered to its original sinusoidal waveform. Digital filtering and protection algorithms are becoming more complex as the cost of computational equipments continues to decrease. In particular, optimal response digital filters, such as Kalman filters can be implemented on presently available devices. Optimal filters are not yet extensively applied because they appear complex and engineers have not become familiar with their use. This thesis presents the basics of the Kalman filtering technique in power system terminology and illustrates use for removal of decaying DC offsets. Effects of unwanted distortions on power system network current phasor quantity during fault could adversely affect the reliability and discrimination of protective relays. This project is principally concerned with the digital concept based on multistate Kalman filtering approach to minimize such problem. There are a variety of reasons because of that DC offset should be removed from power system network. The main detrimental effects of DC offset in alternating networks are half cycle saturation of transformer core, generation of even harmonics addition to odd harmonics, additional heating in appliances leading to a decrease of the lifetime of transformers and rotating machines, and mal operation of protective relays.

Keywords- DC offset, relays, Kalman filter.

Unique Identification Number - IJEDR1402060
Page Number(s) - 1642-1647
Pubished in - Volume 2 | Issue 2 | June 2014
DOI (Digital Object Identifier) -   
Publisher - IJEDR (ISSN - 2321-9939)

  HOMENDRA KUMAR,  ROSHNI RAHNAGDALE,   "REMOVAL OF DECAYING DC OFFSET FROM FAULT CURRENT BY USING KALMAN FILTERING THEORY", International Journal of Engineering Development and Research (IJEDR), ISSN:2321-9939, Volume.2, Issue 2, pp.1642-1647, June 2014, Available at :http://www.ijedr.org/papers/IJEDR1402060.pdf