Onlly relay protection distance protection

Such protection relays are known as “distance protection relays” and only function in case of faults that occur between the location of the protection relay and the chosen reach point. This principle is shown in Figure 1. The former gives an unduly long time delay in fault clearance at the generating station end when there are more than four or five sections and the pilot-wire system becomes too. Distance relays are one of the most important protection elements in a transmission line.