M-LIB3 Low Impedance Bus Differential Relay
24
To compensate the differential current produced by CT’s error or saturation, the actual minimum operation
level IS is dynamically adjusted in function of the actual through current IR according to the set coefficient [1R],
[2R]
• IR < [1IR] : IS = IdS
‚ [1IR] < IR < [2IR] : IS = IdS + 1R(IR-[1IR])
ƒ IR > [2IR] : IS = IdS + 1R([2IR]-[1IR]) + 2R(IR-[2IR])
„ BIAS SATURATION : IS = 10 In for any IR
[2I]
R
∆
IR
[I/In]
ds
∆
IR
∆
Ids
R=
[2R]
∆
Ids
I/InR
[1I]R
‚ƒ„•[1R]
Is/In
∆
Ids