Browsing by Author "Fakruddin, D.B."

Now showing 1 - 3 of 3

Development of wavelet transform based numeric relay for differential protection of power transformer
(2003) Vittal, K.P.; Gaonakar, D.N.; Fakruddin, D.B.
This paper proposes the wavelet transform (WT) based algorithm useful in digital differential protection of transformer. It is shown that, the wavelet transform has more distinct feature extraction property, due to its ability to extract information from the transient signals, simultaneously both in time and frequency. A decision logic has been devised using extracted feature from differential current, so as to distinguish an internal fault from an inrush / over-excitation. The proposed algorithm is evaluated using simulated inrush, over-excitation and internal fault current signals. For this purpose a transient behavioral model of power transformer has been developed using MATLAB software. Results of evaluation study show that, proposed WT based differential protection scheme can over come the problem of false tripping due to inrush/over-excitation.
Development of wavelet transform based numeric relay for differential protection of power transformer
(2003) Vittal, K.P.; Gaonakar, D.N.; Fakruddin, D.B.
This paper proposes the wavelet transform (WT) based algorithm useful in digital differential protection of transformer. It is shown that, the wavelet transform has more distinct feature extraction property, due to its ability to extract information from the transient signals, simultaneously both in time and frequency. A decision logic has been devised using extracted feature from differential current, so as to distinguish an internal fault from an inrush / over-excitation. The proposed algorithm is evaluated using simulated inrush, over-excitation and internal fault current signals. For this purpose a transient behavioral model of power transformer has been developed using MATLAB software. Results of evaluation study show that, proposed WT based differential protection scheme can over come the problem of false tripping due to inrush/over-excitation.
This paper presents a Microcontroller based three phase induction motor protection relay. The scheme employs the Hall effect current transducers for sensing motor line currents, and an ‘Auto ranging ’ feature, in order to acquire motor line currents accurately from no load to blocked rotor current. The flexibility of ‘Operator selectable thermal current versus time (I-T) curves feature’ is incorporated in the relay software, in which using the operator fed cold curve points and the thermal time constant of the motor, the corresponding I-T cold and hot curves can be fitted by the relay Software. The relay performance, with the selected I-T curves has been studied in the laboratory by testing on a three phase, 5 h.p. induction motor and it has been observed that the relay to follow the selected I-T characteristics. © 1998 Taylor & Francis.
(Microcontroller based three-phase induction motor protection relay with operator selectable thermal it curve feature) Vittal, K.P.; Fakruddin, D.B.; Raghavendra Rao, I.; Parthasarathy, K.
1998