GE P444

P
44x/EN AP/Hb6
Application Notes
(AP) 5
-84 MiCOM P40 Agile
P442, P444
3.5.3 Trip logic and Zone 1 extension logic
The following trip logic completes the distance protection by zone:
Figure 58: Trip and Z1X trip logic
Z1X can be used as well as the default scheme logic in case of UNB _Alarm-carrier out of
service (See unblocking logic – Section 3.2.6)
3.5.4 Distance trip equation
The following equation summarizes the distance trip equation (previously shown in logic
diagrams):
Distance Trip logic
(∗)
=
Z1 . T1 . BZ1 . PZ1
+ Z1x' . (None + Z1xChannel_Fail . ‘COS alarm’).(T1 . INP_Z1EXT)
+ ‘DIST. UNB CR’ . T1 . [PZ1 . Z1' + PZ2 . Z2' + PFwd . Aval’]
+ UNB_CR
. T1 . ‘Aid Dist Delay’ + ‘DIST. COS’) . [Z1' . BZ1 + (Z2' . BZ2 . INP_COS )]
+ T2 [Z2' + PZ1 . Z1' + BZ1 . Z1']
+ Z3' . T3
+ Zp' . TZp
+ Zq' . TZq
+ Z4'. T4
Remarks: 1. In case of Carrier Out of Service (COS), the logic swaps back to a
basic scheme.
2. inputs Zx must be polarised for activating Zx logic.
Remarks: 1. In case of COS (carrier out of service), the logic swap back to a
basic scheme.