protection system

consider a stator winding of an alternator with an internal high-resistance ground fault. The currents under the fault condition are as shown in the figure. The winding isprotested using a differential current scheme with current transformers of ratio 4005A as shown. Find the operating current of the coils (Ip). (Smarks) b) Assume that a three phase delta way connected 50MVA6933Kv power transformer is protected by the use of percentage differential relays. If the CTs located on the delsa and way sides are of 400/5 and 1200/5A respectively determine the minum relay current operation setting to permit 25% overload (5marks)