1 A BC DeltaWye a2a2 a1a1 b1b1 b2b2 c2c2 c1c1 a a2a2 a1a1 c1c1 c2c2 b1b1 b2b2 c b A BC B2B2 B1B1 C1C1 C2C2 A2A2 A1A1 Dy 1 Step 1 Step 2

2 D / Y A B C a b c a1a1 a2a2 b1b1 b2b2 c1c1 c2c2 A2A2 A1A1 B2B2 B1B1 C2C2 C1C1 A BC B2B2 B1B1 C1C1 C2C2 A2A2 A1A1 Step 3 Step 4

3 Ia= Ia= 5 Ic= Ic= 15 Ib= Ib= 10 POWER SYSTEM FAULTS SEQUENCE COMPONENT THEORY: I a = I a0 + I a1 + I a2 I a2 I a1 I a0 I b2 I b1 I b0 I c1 I b = I b0 + I b1 + I b2 I c2 I c0 I c = I c0 + I c1 + I c2 I a1 I b1 I c1 I a0 I b0 I c0 I a2 I b2 I c2 I a2 I b2 I c2 I a1 I b1 I c1 I a0 I b0 I c0 Zero Sequence Comps +ve Sequence Comps -ve Sequence Comps

4 Direct Transfer Trip Scheme - ISSUES A B Communication ErrorFalse Tripping