GE Multilin D30 Line Distance Relay 8-58 THEORY OF OPERATION 8.1 DISTANCE ELEMENTS8The limit angle of the comparator is not adjustable and equals 90°. The zero-sequence directional characteristic improvesdirectional integrity for time-delayed operations after the memory expires.l) OVERCURRENT SUPERVISIONThe overcurrent supervision responds to the following currents:AB phase element: (IA – I B) /BC phase element: (IB – I C) /CA phase element: (IC – I A) /A, B, C ground element: 3 × I_0The following tables summarize the characteristics of the distance elementsTable 8–1: DIRECTIONAL MHO PHASE DISTANCE FUNCTIONSCHARACTERISTIC COMPARATOR INPUTS LIMIT ANGLEVariable mho I × Z – V V_1M COMP LIMITReactance I × Z – V I × Z COMP LIMITDirectional I × ZD V_1M DIR COMP LIMITTable 8–2: DIRECTIONAL MHO GROUND DISTANCE FUNCTIONSCHARACTERISTIC COMPARATOR INPUTS LIMIT ANGLEVariable mho I × Z – V V_1M COMP LIMITReactance I × Z – V I_0 × Z COMP LIMITDirectional I_0 × Z D V_1M DIR COMP LIMITDirectional I_2 × Z D V_1M DIR COMP LIMITFault-type I_0 I_2 50°Zero-sequence I_0 × Z D –V_0 90°Table 8–3: DIRECTIONAL QUADRILATERAL PHASE DISTANCE FUNCTIONSCHARACTERISTIC COMPARATOR INPUTS LIMIT ANGLEReactance I × Z – V I × Z COMP LIMITDirectional I × ZD V_1M DIR COMP LIMITRight Blinder I × ZR – V I × Z R 90°Left Blinder I × Z L – V I × ZL 90°Table 8–4: DIRECTIONAL QUADRILATERAL GROUND DISTANCE FUNCTIONSCHARACTERISTIC COMPARATOR INPUTS LIMIT ANGLEReactance I × Z – V j × I_0 × e jΘ or j × I_2 × e jΘ COMP LIMITDirectional I_0 × Z D V_1M DIR COMP LIMITDirectional I_2 × Z D V_1M DIR COMP LIMITRight Blinder I × ZR – V I × Z R 90°Left Blinder I × Z L – V I × ZL 90°Fault-type I_0 I_2 50°Zero-sequence I_0 × Z D –V_0 90°Table 8–5: NON-DIRECTIONAL MHO PHASE DISTANCE FUNCTIONSCHARACTERISTIC COMPARATOR INPUTS LIMIT ANGLEOffset mho I × Z – V I × Z REV – V COMP LIMIT333
