E-57
Computations
Power Quality Recorder SIMEAS Q80 7KG8080, Operating instruction
E50417-B1074-C419-A2, Release 09.02.2011
11.1.3 Data recording procedures
11.1.3.1 Overview
The following table pairs power network quality indicators with their respective data acquisition techniques.
Network quality and data
Attribute
Acquisition procedure
Resolution
Curve type
acc. EN 50160
add. in SIMEAS Q80
7KG8080
Network frequency
mean value
histogram
10 s *
data-reduced,
normal
Slow voltage variations
mean values
10 min
normal
Fast voltage variations
curve plots
U
rms1/2
**
data-reduced
Events (voltage sags and outages)
tables of curve
values
U
rms1/2
---
Harmonics voltage, interharmonics
mean values
10 min
normal
Voltage asymmetry
mean values
10 min
normal
Signal voltages
mean values
curve plots
10 /12 cycle,
10 min
data-reduced
* The values indicated are default values and can be changed.
** U
rms1/2
: Value of the r.m.s. voltage measured over 1 cycle, commencing at a fundamental zero crossing, and
refreshed each half cycle.
11.1.3.2 Mean values
Mean values can be used for long-term analysis of voltage, current and power. This includes upper harmonics and
symmetry.
The interval duration for forming the mean value (the time resolution) is adjustable. According to EN 50160, the
aggregation interval for most computations is 10 minutes.
11.1.3.3 Curve plots
Curve plots describe the course of a quantity over time, usually the course of the RMS-values of voltages or currents
with a resolution of 1/2 cycle.
Each data point in a curve plot consists of two values: the amplitude and the time (XY-waveform). This results in a
reduction of data volume, since only one point must be saved if the original signal changes substantially.
The desired accuracy must be entered as a parameter. The default value has been set to conform to EN 50160
standards for network power quality.
Events (such as voltage dips and power outages) are extrapolated from the curve plots after measurement. For this
reason, it is not yet necessary to set limit values when setting up measurement.
