Thytronic SME2-IS User Manual

53
SME2-IS - Manual - 06- 2021
FUNCTIONAL CHARACTERISTICS
— Automatic faulty branch selection function
The SME2-IS can be enabled or disabled to automatically select the faulty branch; if enabled, the
device has the functions required to automatically select the faulty branch in:
• FSL (logical selectivity function)
• FRT (voltage relaunch function)
which are mutually exclusive.
FRT function
The automatic faulty branch selection function FRT is selected by a conguration parameter during
calibration (exclusive with FSL and hence does not consider the communication).
If this mode is selected, BLIND logic is not used.
When one of the fault conditions is detected, the corresponding signal is issued (along with the open
breaker command in case of extended conguration) after an intentional delay equal to that cong-
ured in the section “protection function”, if the fault condition has not resolved itself in the meantime.
The signal (and trip, in case of extended conguration) is thus issued after a time:
t>>
def
(T_rit_51.S2) for a 51.S2 fault;
t>>>
def
(T_rit_51.S3) for a 51.S3 fault;
t
ED
>
def
(T_rit_67.S1) for a 67.S1 fault;
t
ED
>>
def
(T_rit_67.S2) for a 67.S2 fault;
t
ED
>>>
def
(T_rit_67.S3) for a 67.S3 fault.
FSL
To block the tripping of a given protection function, one can use the selective block function (FSL).
[1]
Logical selectivity has been developed to reduce the time required to eliminate faults which, in sca-
lar time system would require programming signicantly long tripping times for the power sources.
The block information must be sent to the upline device; the block output is acquired by the upline re-
lay, the information is transmitted using the IEC 61850 protocol, and prevents indiscriminate tripping
of all devices affected by the fault current.
The block function is only tripped if the FSL function is active.
Operating logic
The automatic faulty branch selection function FSL is selected by a conguration parameter during
calibration or by an IEC 61850 message (mutually exclusive with FRT and hence considers the com-
munication).
The objective of FSL is to select exclusively the branch line affected by the fault, using real time
communications between the IEDs (RGDM-I, IC, DV901A3) on the same MV line.
FSL exchanges temporary opening disable signals (BLIND) via IEC 61850 messages (goose).
The logical selectivity function has 2 different ways of handling the wait time of BLIND signals com-
ing from other IEDs, which can be applied whether using the “publisher list” technique or the “BLIND
with comparison” technique.
The is determined during calibration, as follows:
• FSL1: BLIND WAIT ALWAYS ACTIVE
• FSL2: BLIND WAIT FOR FIRST FAULT OCCURRENCE ONLY
• FRT
FSL1 and FS2
For both options, when the following conditions hold:
A) Initial condition: no fault for at least three minutes with voltage present
B) Fault detected
the following sequence of operations is executed:
• the BLIND signals are sent via the GOOSE IEC 61850 protocol in multi-cast mode;
• a wait window is activated (Tatt)
• a wait window is activated (Tr) (with Tr>Tatt)
• if the fault conditions expires within Tatt, the automation returns to standby;
• if the fault condition is not resolved within Tatt and not even one BLIND signal is received from an
IED on the subscriber list, when Tatt expires the RGDM-I must:
A) report the fault condition to UP;
B) open the DY800 (terminal block MI), in case of extended conguration.
• If, whether or not a BLIND signal is received, the fault condition persists until Tr expires, the auto-
mation-I must:
A) report the fault condition to UP;
B) open the DY800 (terminal block MI), in case of extended conguration.
Note 1 In the following description, the logical selectivity block will be called either “Logical selectivity block” or “Block2”

Thytronic SME2-IS Specifications

General

Brand	Thytronic
Model	SME2-IS
Category	Security Sensors
Language	English