Title :
A Kalman filter based digital percentage differential and ground fault relay for a 3-phase power transformer
Author :
Murty, Y.V.V.S. ; Smolinski, W.J.
Author_Institution :
Dept. of Electr. Eng., New Brunswick Univ., Fredericton, NB, Canada
fDate :
7/1/1990 12:00:00 AM
Abstract :
The design and real-time implementation of a Kalman-filter-based digital percentage differential and a ground-fault protection scheme for three-phase power transformers are presented. A set of eleven-state Kalman filters is used to estimate the fundamental and up to fifth harmonic components of the transformer current signals. The protective relay is equipped with an even harmonic restraint during magnetizing inrush conditions and a fifth harmonic restraint during overexcitation conditions. The restraint during external faults is provided by means of a percentage differential characteristic. The relay operates in half a cycle during internal faults. In order to achieve sensitive ground-fault protection, separate primary and secondary ground-fault protection are provided. The relay algorithm is implemented on a single TMS320 digital signal processor and tested in real time using a three-phase laboratory power transformer
Keywords :
Kalman filters; digital control; digital signal processing chips; power engineering computing; power transformers; transformer protection; DSP; Kalman filter; TMS320 digital signal processor; algorithm; current signals; digital control; digital percentage differential; fundamental; ground fault relay; harmonic; internal faults; magnetizing inrush conditions; overexcitation; power engineering computing; protection; three-phase power transformers; Digital relays; Digital signal processors; Laboratories; Magnetic separation; Power harmonic filters; Power transformers; Protective relaying; Signal processing algorithms; Surge protection; Testing;
Journal_Title :
Power Delivery, IEEE Transactions on
