GE D90 Plus Instruction Manual page 494

AUTOMATION LOGIC
484
Figure 418: Remote voltage magnitude calculation logic
Now that the remote voltage magnitude has been calculated, the following logic
calculates the voltage difference between this and the setting voltage.
Figure 419: Voltage difference automation logic
The current on each phase is checked to ensure that it is less than the maximum allowable
for a tap changer operation.
Figure 420: Overcurrent check automation logic
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 8: AUTOMATION