Design a suitable protection scheme for the five buses ring network shown in Figure 1. All time-overcurrent relays are definite-time overcurrent (DTOC) relays. Assume that the minimum time setting of the line relays is 0.2 s and the time grading is 0.2 s. CB1 CB2 3D 0.4 s Feeder B 10 CB3 L5 L2 CB9 CB4 TE = 0.4 s Tc = 0.4 s Feeder E Feeder C CB8 CB5 L3 CB7 CB6 Tp = 0.4 s Feeder D Figure 1