Simplified Block Diagrams - ABB Relion Technical Manual

Section 6
Differential protection
6.4.6.6
Phasors IAN, IBN,ICN
Phasors IAT, IBT,ICT
Samples IAN, IBN,ICN
Samples IAT, IBT,ICT
The sensitive protection is deactivated
above bias current > 150 % rated
Phasor IAN (neg.seq.)
Phasor IAT (neg.seq.)
ANSI06000434 V2 EN
Figure 56: Principle design of the generator differential protection
146

Simplified block diagrams

The principle design of the generator differential protection is shown in figure 56.
Magnitude
Idiff and Ibias
Calculation
Idiff and Ibias
Calculation
Samples Idiff
instantaneous
Idiff
current.
Calculation
negative
sequence
Idiff
Simplified logic diagrams of the function is shown in figures below.
Pickup
phase
selective
Diff.prot.
characteristic
Harm.
Hamonic
Block
analysis: DC,
2nd and 5th
Intern/
Internal/
extern
External Fault
Fault
Discriminator
and Sensitive
differential
protection
1MRK 502 048-UUS A
TRIP
Signals
PICKUP
Signals
BLOCK
Signals
Pickup
INTFAULT
and trip
EXTFAULT
logic
OPENCT
OPENCTAL
Analog
Outputs
en06000434-2_ansi.vsd
Technical manual