Frequency Measurement Fmmxu - ABB RELION REX640 Technical Manual

Section 8
Measurement functions
8.1.9
8.1.9.1
8.1.9.2
8.1.9.3
8.1.9.4
1316

Frequency measurement FMMXU

Identification
Function description
Frequency measurement
Function block
GUID-073E21AC-F9E5-4923-91ED-7B806D16DF58 V2 EN
Figure 708: Function block
Functionality
The frequency measurement range is 35...75 Hz. The measured frequencies outside
the measurement range are considered to be out of range and the minimum and
maximum values are then shown in parentheses.
There is an extended range of 10...75 Hz in a 50 Hz network and 12...75 Hz in a 60 Hz
network. The measured frequencies outside 35...75 Hz are shown in parentheses.
When the frequencies cannot be measured, for example, due to too low voltage
amplitude, the default value for frequency measurement can be selected with the Def
frequency Sel setting parameter. In the "Nominal" mode the frequency is set to 50 Hz
(or 60 Hz) and in "Zero" mode the frequency is set to zero and shown in parentheses.
FMMXU provides instantaneous frequency in hertz which is available for application
configurations through output F_INST.
Signals
Table 1252: FMMXU Input signals
Name Type
U3P SIGNAL
Table 1253: FMMXU Output signals
Name Type
F_INST FLOAT32
IEC 61850 IEC 60617
identification identification
FMMXU f
Default Description
- Three-phase voltages
Description
Frequency, instantaneous value
1MRS759142 C
ANSI/IEEE C37.2
device number
f
REX640
Technical Manual