Recording Channels - Siemens SIMEAS R-PMU Manual

7
7.1 Phasor Measurement Unit (PMU)
7.1.1

Recording Channels

The AC DAUs that have been activated for the PMU in the system transmit either the phasors of
the measuring signals or the positive-sequence system. In case of the positive-sequence signal
transmission the 4th and the 8th channels are not transmitted. No data is transmitted from DAUs
that have been disabled.
In addition to the phasors, the frequency, the frequency change per second and the binary data
of the data acquisition units are transmitted. DDAUs transmit Process values (DC values) as
analog values in the PMU telegram. The frequency transmitted with DDAUs is the nominal
frequency.
The data can be transmitted either in the 16 bit integer or the 32 bit floating point format. The
32 bit format allows for a higher resolution of the measured data, however, also requires higher
data transfer rates. The 32 bit floating point is supported via LAN only in case of PMU data
communication.
Note
In case of the 16 bit integer format DDAU, data is displayed with a zoom factor of 10
and transmitted as pure measured values, even if no 1:1 ratio to process variables has been
parameterized.
The x axis displacement and the amplification factor that can be parameterized in OSCOP P are
not PMU relevant for AC DAUs and DDAUs. These two parameters are only relevant for the
display module of OSCOP P.
For an overview of the transmission channels of the individual DAU types depending on the
connection, please see Table 7-2 and 7-3.
Table 7-2
Star
connection
Delta
connection
56
Recorded values of the DAUs for acquiring AC values depending on the input
connection
VCDAU
V , V , V , V
L1 L2 L3 N
V
1
I , I , I , I
L1 L2 L3 N
I
1
f, Δf
B to B
1 16
V , V , V , V
L12 L23 L31 4
V
1
I , I , I , I
L1 L2 L3 4
I
1
f, Δf
B to B
1 16
VDAU
V , V , V , V
L1-1 L2-1 L3-1 N4
V
1
V , V , V , V
L1-2 L2-2 L3-2 N8
V
1
f, Δf
B to B
1 16
V , V , V , V
L12-1 L23-1 L31-1 4
V
1
V , V , V , V
L12-2 L23-2 L31-2 8
V
1
f, Δf
B to B
1 16
Digital Fault Recorder, SIMEAS R-PMU, Manual
E50417-H1076-C360-A5, Release 10.2012
9
in the PDC
CDAU
I , I , I , I
L1-1 L2-1 L3-1 N4
I
1
I , I , I , I
L1-2 L2-2 L3-2 N8
I
1
f, Δf
B to B
1 16
I , I , I , I
L1-1 L2-1 L3-1 4
I
1
I , I , I , I
L1-2 L2-2 L3-2 8
I
1
f, Δf
B to B
1 16