TY  - BOOK
AU  - Maurya, Shyam Sundar
AU  - Shaik, Abdul Gafoor
TI  - Wavelet based Transformer Protection scheme 
U1  - 621.313 
PY  - 2018///
CY  - IIT Jodhpur
PB  - Department of Electrical Engineering
KW  - Transformer Protection scheme
KW  - MTech Theses
KW  - Department of Electrical Engineering
N2  - "A  transformer  is  one  of  the  essential  parts  of  the  power  systemnetwork. Since  the  power transformer outage can cause great blackouts, its protection is one of the challenging subjects in the  area  of  power  system  protection. The  crucial  objective  of  protective  system  network  is  to reduce  the  mal-operation  and  enhance  the  reliability  of  electric  energy  flow  in  power  system network.The  conventionalDifferential protection  is  used  to protect  transformer  frominternal faults and restrains during inrush currents and external faults, with the help of restraining coil. The restraint signal reduces the sensitivity of the uses relay. Hence there is need to investigate in to  new  methods  which  coil  restrain  the  relay  from  external  fault  and  inrush  current  with advanced signal processing technique.The proposed research work aims at using Wavelet transform based multi-resolution analysis for transformer protection. For the analysis, three phase current signals are measured and sampled from the primary  winding  of  the transformer.  These  signals  are  decomposed  with db2  mother wavelet  to  obtain  approximate  coefficients  using  wavelet  transform.  A  cumulative  summation index  is  obtained by  summation  these  approximate  coefficients  over  a  moving  window  of  half cycle.  This  index  is  compared  with  the  threshold  for  fault  detection  and  classification.  The proposed algorithm was found to be successful in the detecting and classifying the internal fault and discriminate the other transients associated with external fault and inrush current.
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ER  -