Siemens SENTRON PAC5200 - Measuring and Recording System

4 Measurands and Recording
4.1 Measuring and Recording System
26 SENTRON PAC5100/5200, 7KM5212/5412, Device Manual
E50417-H1040-C568-A1, Edition 03.2015
4.1 Measuring and Recording System
4.1.1 Functioning of the Measuring System according to IEC 61000-4-30
SENTRON PAC5100/5200 devices measure the power quality according to IEC 61000-4-30 in 1-phase or
multi-phase distribution systems. The measuring system is implemented according to class A. In terms of
functional scope, measuring ranges, and accuracy, the SENTRON PAC5100/5200 devices are class S.
The basic measuring interval for determining the values for mains voltage, harmonics of mains voltage, and
mains voltage unbalance is a 10-period time interval for 50-Hz distribution systems or a 12-period time interval
for 60-Hz distribution systems. The measurement of the 10-/12-period time intervals is resynchronized at each
RTC 10-minute limit.
Subsequently, the values for the 10-/12-period time intervals are aggregated over additional time intervals (for
example, 10-minute interval at SENTRON PAC5200).
10-Minute Interval (SENTRON PAC5200)
The value aggregated in a 10-minute interval is tagged with the absolute time (for example 01:10:00). The time
at the end of the aggregation interval is indicated as the time qualifier. The values for the 10-minute time interval
are calculated without interruption from the 10-/12-period time intervals.
• Each 10-minute interval begins at an RTC 10-minute limit. At this 10-minute limit, the 10-/12-period time
intervals are aggregated over a 10-minute interval. The last 10-/12-period time interval in a 10-minute
aggregation interval overlaps in time at an RTC 10-minute limit. Each overlapping 10-/12-period time
interval (for the overlapping area, see Figure 4-1) is included in the aggregation interval of the preceding
10-minute interval.
• The aggregation interval enables the power system quality to be evaluated according to EN 50160. The
aggregation interval can be adjusted to other applications using a parameter. A shorter aggregation
interval increases the storage capacity required for measured values and reduces the maximum possible
recording time in the memory.
Figure 4-1 Synchronization of the Aggregation Intervals for Class A
RTC
10-minute
limit
k
10-minute interval (x+1)
j
10/12 periods
i
1
2 3
Overlapping area
10-minute interval (x)
10/12 periods
10/12 periods 10/12 periods
10/12 periods
10/12 periods