Alstom MiCOM P546 - 1.5.2 Tripping mode - selection of single or three phase tripping; 1.5.3 Pole dead logic

Operation P54x/EN OP/La4
MiCOM P543, P544, P545 & P546 (OP) 5-27
OP
1.5.2 Tripping mode - selection of single or three phase tripping
This selects whether instantaneous trips are permitted as Single pole, or will always be 3
pole. Protection elements considered as “instantaneous” are those normally set to trip with
no intentional time delay, i.e.: Differential, directional earth/ground DEF aided scheme and if
fitted, Zone 1 distance and distance channel aided scheme. The selection 1 and 3 pole
allows single pole tripping for single phase to ground faults. The selection 3 pole converts
all trip outputs to close Trip A, Trip B and Trip C contacts simultaneously, for three pole
tripping applications.
In the case of the P544/P546, the tripping mode can be set independently for the two circuit
breakers controlled.
Logic is provided to convert any double phase fault, or any evolving fault during a single pole
auto-reclose cycle into a three phase trip. Two phase tripping is never permitted. This
functionality is shown in Figure 12 for P543/P545 and in AR Figure 63 (logic diagram
sup
plement) for P544/P546 models.
DDB: Trip Output C (525)
DDB: Trip Inputs A (530)
DDB: Trip Inputs B (531)
DBD: Trip Inputs C (532)
DDB: Trip Inputs 3ph (529)
DDB: Force 3Pole Trip (533)
DDB: Trip Output B (524)
DDB: 3ph Fault (528)
DDB : 2/3 ph
Fault (527)
DDB: Any Trip (522)
>=2
DDB: Poledead A
(892)
DDB: Poledead B
(893)
DDB: Poledead C
(894)
DDB: Trip 3ph (526)
1
1
1
1
&
&
&
1
&
1
1
1
1
DDB: Trip Output A (523)
&
1
Dwell
100ms
S
R
S
R
S
R
Q
S
R
S
R
Q
S
R
P1587ENb
Figure 12 Trip conversion scheme logic
1.5.3 Pole dead logic
Pole dead lo
gic is used by the relay to determine when the circuit breaker poles are open
(“pole dead”). This indication may be forced, by means of status indication from CB auxiliary
contacts (52a or 52b), or internally determined by the relay. When no auxiliary contacts are
available, the relay uses lack of phase current (Setting: CB FAIL & I</UNDER CURRENT/I<
Current Set), and an undervoltage level detector (pick up fixed at 38.1 V - drop off fixed at
43.8 V to declare a “pole dead”.
Note: If the VT is connected at the busbar side, auxiliary contacts (52a or
52b) must be connected to the relay for a correct pole dead indication.
The logic diagrams, Figure 13 and Figure 14 below show the details: