ABB REG670 Applications Manual

11.3 Rate-of-change of frequency protection SAPFRC
11.3.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Rate-of-change of frequency protection SAPFRC
df/dt
>
<
SYMBOL-N V1 EN
81
11.3.2 Application
Rate-of-change of frequency protection (SAPFRC) is applicable in all situations,
where reliable detection of change of the fundamental power system voltage
frequency is needed. SAPFRC can be used both for increasing frequency and for
decreasing frequency. SAPFRC provides an output signal, suitable for load shedding
or generator shedding, generator boosting, HVDC-set-point change, gas turbine start
up and so on. Very often SAPFRC is used in combination with a low frequency signal,
especially in smaller power systems, where loss of a fairly large generator will require
quick remedial actions to secure the power system integrity. In such situations load
shedding actions are required at a rather high frequency level, but in combination with
a large negative rate-of-change of frequency the underfrequency protection can be
used at a rather high setting.
11.3.3 Setting guidelines
The parameters for Rate-of-change frequency protection SAPFRC are set via the local
HMI or or through the Protection and Control Manager (PCM600).
All the frequency and voltage magnitude conditions in the system where SAPFRC
performs its functions should be considered. The same also applies to the associated
equipment, its frequency and time characteristic.
There are two application areas for SAPFRC:
1. to protect equipment against damage due to high or too low frequency, such as
generators, transformers, and motors
2. to protect a power system, or a part of a power system, against breakdown by
shedding load or generation, in situations where load and generation are not in
balance.
SAPFRC is normally used together with an overfrequency or underfrequency
function, in small power systems, where a single event can cause a large imbalance
between load and generation. In such situations load or generation shedding has to
Section 11 1MRK 502 071-UEN -
Frequency protection
440 Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual

ABB REG670 Specifications

General

Brand	ABB
Model	REG670
Category	Protection Device
Language	English