ABB RES670 Technical Manual page 329

1MRK 511 408-UUS A
Comparator
FreqHighLimit <=
FreqLowLimit
ERROR
Comparator
f <= FreqHighLimit
f > FreqLowLimit
PICKUP
V3P
Comparator
V <= VHighLimit
01
V >= VLowLimit
01
Comparator
I3P
I < PickupCurrentLevel
CBOPEN
CBCLOSE
LOADINIT
RESETACC
HOLDTIME
BLOCK
ANSI12000609 V1 EN-US
Figure 112: Logical diagram
Phasor measurement unit RES670 2.2 ANSI
Technical manual
If
Then
If
AND
Then
AND
To achieve a proper operation, the set frequency high limit should be more than the set
frequency low limit. To avoid malfunction, a check is performed that FreqHighLimit is
greater than FreqLowLimit. If not, the ERROR signal is activated.
FTAQFVR (81A) can be instantiated with one or more frequency ranges according to
the turbine manufacturer's specification. When the frequency falls in to the common
zone when two frequency ranges overlap it is necessary to block one instance and keep
only one instance of FTAQFVR (81A) active. The STRORHLD output is activated
when either the BFI_3P output is active or when the HOLDACC input signal is on. The
STRORHLD output is connected to the input HOLDACC of the other instance of
FTAQFVR (81A).
FREQ
FREQOK
VOLTOK
PICKUP
Signal Routing
Based on
Generator
PICKUP
Start or Stop
Detection Logic
and
Voltage Band Limit
Check Logic
Section 10
Frequency protection
Accumulation time
counter
Continuous time
counter
TRIPCONT
AND
Pickup & Trip
Output Logic
ACCALARM
STRORHLD
LASTEVTD
ANSI12000609-1-en.vsd
ERROR
FREQ
FREQOK
VOLTOK
BFI_3P
TRIPACC
TRIP
ACCTIME
323