ABB Relion RES670, Technical Manual, Page: 797 / 934

The output signal AI1 to AI4 are direct output of the, in SMT, connected input to
GRPx_A, GRPxB, GRPxC and GRPx_N, x=1-12. AIN is always calculated residual
sum from the first three inputs. A3P is grouped, three-phase information containing all
relevant information about four connected inputs. Note that all other functions, with a
few exceptions, use this output in configuration. Note that the SMAI function will
always calculate the residual sum of current/voltage if the input GRPxN is not
connected in SMT. Applications with a few exceptions shall always be connected to
AI3P.
22.9.5.1 Frequency values
GUID-B494B93C-B5AA-4FD6-8080-8611C34C2AD8 v5
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 MinValFreqMeas , the function freezes the
frequency output value for 500 ms 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.
MinValFreqMeas is set as % of VBase /√3
If SMAI setting ConnectionType is Ph-Ph , at least two of the inputs GRPx_A,
GRPx_B and GRPx_C, 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
ConnectionType is Ph-N , all three inputs GRPx_A, GRPx_B and GRPx_C must be
connected in order to calculate the positive sequence voltage.
If only one phase-phase voltage is available and SMAI setting ConnectionType is Ph-
Ph , the user is 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 303 to make SMAI calculate a
positive sequence voltage.
SMAI1
BLOCK
DFTSPFC
REVROT
^GRP1_A
^GRP1_B
^GRP1_C
^GRP1_N
SPFCOUT
G1AI3P
G1AI1
G1AI2
G1AI4
G1N
NEUTRAL
PHASEC
PHASEB
PHASEA
VAB
SAPTOF
V3P*
BLOCK
BLKTRIP TRIP
PICK UP
BLKDMAGN
FREQ
TRM_40.CH7(U)
SAPTOF(1)_TRIP
ANSI10000060-1-en.vsdx
ANSI10000060 V1 EN-US
Figure 303: Connection example
The above described scenario does not work if SMAI setting
ConnectionType is Ph-N . If only one phase-ground voltage is available,
1MRK 511 408-UUS A
Section 22
Basic IED functions
Phasor measurement unit RES670 2.2 ANSI 791
Technical manual