ABB Relion 670 Series Applications Manual page 499

1MRK 511 358-UUS A
21.11.2 Frequency values
The SMAI function includes a functionality based on the level of positive sequence voltage,
MinValFreqMeas , to validate if the frequency measurement is valid or not. If the positive sequence
voltage is lower than
and after that the frequency output is set to the nominal value. A signal is available for the SMAI
function to prevent operation due to non-valid frequency values.
VBase /√3
If SMAI setting
where 1≤x≤12, must be connected in order to calculate the positive sequence voltage. Note that
phase to phase inputs shall always be connected as follows: A-B to GRPxA, B-C to GRPxB, C-A to
GRPxC. If SMAI setting
be connected in order to calculate the positive sequence voltage.
If only one phase-phase voltage is available and SMAI setting
advised to connect two (not three) of the inputs GRPx_A, GRPx_B and GRPx_C to the same voltage
input as shown in figure
TRM_40.CH7(U)
ANSI10000060 V1 EN-US
Figure 227: Connection example
Application manual
MinValFreqMeas , the function freezes the frequency output value for 500 ms
ConnectionType is Ph-Ph , at least two of the inputs GRPx_A, GRPx_B and GRPx_C,
ConnectionType is Ph-N , all three inputs GRPx_A, GRPx_B and GRPx_C must
227 to make SMAI calculate a positive sequence voltage.
SMAI1
SPFCOUT
BLOCK
DFTSPFC G1AI3P
VAB
REVROT
PHASEA
^GRP1_A
PHASEB
^GRP1_B
PHASEC
^GRP1_C
NEUTRAL
^GRP1_N
The above described scenario does not work if SMAI setting
N . If only one phase-ground voltage is available, the same type of connection can
be used but the SMAI
accounted for when setting
N and the same voltage is connected to all three SMAI inputs, the positive
sequence voltage will be zero and the frequency functions will not work properly.
The outputs from the above configured SMAI block shall only be used for
Overfrequency protection (SAPTOF, 81), Underfrequency protection (SAPTUF, 81)
and Rate-of-change frequency protection (SAPFRC, 81) due to that all other
information except frequency and positive sequence voltage might be wrongly
calculated.
SAPTOF
V3P*
BLOCK
G1AI1
BLKTRIP BLKDMAGN
G1AI2
G1AI4
G1N
ConnectionType setting must still be Ph-Ph and this has to be
MinValFreqMeas . If SMAI setting ConnectionType is Ph-
GUID-B494B93C-B5AA-4FD6-8080-8611C34C2AD8 v5
MinValFreqMeas is set as % of
ConnectionType is Ph-Ph , the user is
TRIP SAPTOF(1)_TRIP
PICK UP
FREQ
ANSI10000060-1-en.vsdx
ConnectionType is Ph-
Section 21
Basic IED functions
493