Q. no. Q.1(a) Compare the differential protection schemes used for synchronous generator with that used for the three phase star-delta power transformer. (b) (i) (ii) Distance relays are always preferred for primary protection of EHV lines as compared to overcurrent relays. Justify this statement. Sketch three stepped distance protection scheme used in EHV lines and tabulate the percentage coverage provided by each of the three distance relays and setting of operating times for achieving appropriate selectivity. Q. no. Q.1(a) Compare the differential protection schemes used for synchronous generator with that used for the three phase star-delta power transformer. (b) (i) (ii) Distance relays are always preferred for primary protection of EHV lines as compared to overcurrent relays. Justify this statement. Sketch three stepped distance protection scheme used in EHV lines and tabulate the percentage coverage provided by each of the three distance relays and setting of operating times for achieving appropriate selectivity