ABB REC670 Applications Manual page 115

1MRK 511 401-UUS A
Bay control REC670 2.2 ANSI
Application manual
• To measure the power system related AC quantities (voltage, current) and to
calculate the phasor representation of these quantities.
• To synchronize the calculated phasors with the UTC by time-tagging, in order to
make synchrophasors (time is reference).
• To publish all phasor-related data by means of TCP/IP or UDP/IP, following the
standard IEEE C37.118 protocol.
The C37.118 standard imposes requirements on the devices and describes the
communication message structure and data. The PMU complies with all the standard
requirements with a specific attention to the Total Vector Error (TVE) requirement.
The TVE is calculated using the following equation:
2
- +
( X ( n ) X ) ( X ( n ) X )
r r
=
TVE
2
+
X X
r
GUID-80D9B1EA-A770-4F50-9530-61644B4DEBBE V1 EN-US
where,
X (n) and X (n) are the measured values
r i
X and X are the theoretical values
r i
In order to comply with TVE requirements, special calibration is done in the factory on
the analog input channels of the PMU, resulting in increased accuracy of the
measurements. The IEEE C37.118 standard also imposes a variety of steady state and
dynamic requirements which are fulfilled in the IED with the help of high accuracy
measurements and advanced filtering techniques.
Figure 37 shows an overview of the PMU functionality and operation. In this figure,
only one instance of PMUREPORT (PMUREPORT1) is shown. Note that connection
of different signals to the PMUREPORT, in this figure, is only an example and the
actual connections and reported signals on the IEEEC37.118/1344 can be defined by
the user.
Wide area measurement system
2
-
i i
2
i
Section 6
(Equation 11)
109