Siemens SIPROTEC 5 Manual page 154

Function-Group Types
6.4 Function-Group Type Phasor Measurement Unit (PMU)
[dwgeopdc-061011-01.tif, 1, en_US]
Figure 6-14
Reference Point for Determining the Angle
The phase angle of a measuring signal X
which is synchronized with the UTC time reference (see
[dwutcphi-260112-01.tif, 1, en_US]
Figure 6-15
154
Geometric Representation of a Phasor
is determined relative to a cosine function having a rated frequency,
m
Determination of Phase Angle ρ of Measuring Signal X
Figure 6-15).
Relative to the Cosine Function
m
SIPROTEC 5, Fault Recorder, Manual
C53000-G5040-C018-5, Edition 11.2017