A WAVELET BASED DIFFERENTIAL ALGORITHM FOR BUSBAR PROTECTION
Busbar protection is an essential component in power system design, protecting the most important system node for network stability and security. When faults occurs on busbar itself, it takes much time to isolate the bus from source which may cause much damage in the bus system. Faults in power system are classified as internal and external faults. Faults within the zone are termed as internal faults whereas, the faults outside the Zone are called as external faults. Ideally, a relay looking after the protection of a zone should operate only for internal faults. It should restrain from operating for external faults or through faults. In this paper the busbar protection using differential protection scheme has been investigated for internal and external faults. An algorithm has been developed to improve the selectivity of the relay and the same has been tested in IEEE9 bus system for internal and external faults. Separation of De-noised signal from fault signal is made using wavelet transform so that the nature of fault occurs on the system can be identified. In this study Daubechies 4 at level 3 is used to separate original signal and de-noised signal. The entire simulation has been done using MATLAB R2017a.
 Mohindar S.Sachdev, Life Fellow, S. Sidhu, Harjeet Singh Gill, July 2000, “A Busbar Protection Technique and Its Performance During CT Saturation and CT Ratio-Mismatch”, IEEE transactions on power delivery, Vol. 15, No. 3, July 2000.
 Y.C. Kang, J.S. Yun, B.E. Lee, S.H. Kang, S.I. Jang and Y.G. Kim, “Busbar Differential Protection in Conjunction with a Current Transformer Compensating Algorithm”, IET Generation Transmission Distribution ,2008, 2, (1),pp. 100-109.
 Yong-Cheol Kang, Ui-Jai Lim, Sang-Hee Kang, Peter A. Crossley, April 2005, “A Busbar Differential Protection Relay Suitable for Use with Measurement Type Current Transformer”, IEEE transactions on power delivery, Vol. 20, No. 2, April 2005.
 Cesareo Fernandez, October 2001, “An Impedance– Based CT Saturation Detection Algorithm for Bus-bar Differential Protection”, IEEE transactions on power delivery, Vol. 16, No. 4, October 2001.
 M. M. Eissa, “High-speed differential busbar protection using wavelet packet transform,” Proc. Inst. Elect. Eng. Gen., Transm. Distrib., vol. 152, no. 6, pp. 927–933, Nov. 2005.
 Saeed AshariGovar, Saeid Heidari, Heresh Seyedi, Saeid Ghasemzadeh, October 2017, “Adaptive CWT-based overcurrent protection for smart distribution grids considering CT saturation and high-impedance fault”, IET Generation Transmission Distribution ,2018, Vol.12, Iss 6.
 Asghari Govar, S., Seyedi, H.: ‘Adaptive CWT-based transmission line differential protection scheme considering cross-country faults and CT saturation’, IET. Gener. Transm. Distrib. 2016, 10, (9), pp. 2035–2041.
 Mahari, A., Seyedi, H.: ‘High impedance fault protection in transmission lines using a WPT based algorithm’, Int. J. Electr. Power Energy Syst., 2015, 67,pp. 537–545
 Samantaray, S.R.: ‘Ensemble decision trees for high impedance fault detection in power distribution network’, Int. J. Electr. Power Energy Syst., 2012, 43, (1), pp. 1048–1055
 Bakar, A.H.A., Ali, M.S., Tan, C., et al.: ‘High impedance fault location in 11kV underground distribution systems using wavelet transforms’, Int. J. Electr.Power Energy Syst., 2014, 55, pp. 723–730
 M. Kezunovic´, “Experimental evaluation of EMTP-based current transformer models for protective relay transient study,” IEEE Trans. PWRD, vol. 9, no. 1, pp. 405–413, Jan. 1994.
 M. S. Sachdev and M. A. Baribeau, “A new algorithm for digital impedance relays,” IEEE Trans. PAS, vol. 98, no. 6, pp. 2232–2240, Nov./Dec. 1979
 M. S. Sachdev and M. A. Baribeau, “A new algorithm for digital impedance relays,” IEEE Trans. on Power Apparatus and Systems, vol.98, no. 6, pp. 2232–40, Nov./Dec. 1979.
 Mohammed, M.E.: ‘High-speed differential busbar protection using wavelet-packet transform’, IEE Proc., Gen. Transm. Distrib., 2005, 152, (6), pp. 927–933
 Eissa, M.M.: ‘High-speed differential Busbar protection using wavelet packet transform’, IEE Gener. Transm. Distrib. Proc., 2005, 152, (6), pp. 927–933
 Gafoor, S.A., Rao, P.V.R.: ‘A new wavelet transform based busbar protection’. TENCON 2006, IEEE Region 10 Conf., November 2006,pp. 1–4