SATEC SA300 ezPAC Operation Manual - Manual (Page 98)

Chapter 8 Configuring Recorders Configuring the EN50160 Power Quality Recorder
98 SA300 Substation Automation Unit
Frequency Variations
Method of Evaluation
The basic frequency measurement is the mean value of the frequency over fixed time
intervals of 10 seconds under normal operating conditions.
A frequency variation is not evaluated if the supply voltage crosses a voltage
tolerance limit (
±15% Un).
Target Values
The ranges of frequency variations given in the EN50160 are:
50Hz ±1% for 95% of a week
50Hz ±1% for 99.5% of a year
50Hz+4/-6% for 100% of the time
The same limits are used for 60Hz systems. The frequency compliance limit can be
programmed in the device in percent of the nominal power frequency via the
EN50160 PQ Recorder setup.
Supply Voltage Variations
This characteristic defines slow variations of steady state supply voltage magnitude.
Method of Evaluation
The basic supply voltage magnitude measurement is the RMS value of the steady
state voltage over a period of 10 minutes under normal operating conditions.
A voltage variation is not evaluated if the supply voltage crosses a voltage tolerance
limit (
±15% Un).
Target Values
The range of voltage variations given in the EN50160 is:
±10% Un for 95% of a week
The supply voltage compliance limit can be changed in the device via the EN50160
PQ Recorder setup.
Rapid Voltage Changes
Rapid voltage changes are sudden but relatively weak voltage variations between
two steady state voltage levels.
Method of Evaluation
Evaluation of rapid voltage changes is made on an hourly basis. The RMS voltage is
evaluated over 3-second time integration intervals. The device establishes the
maximum difference of the RMS voltage between two intervals selected from three 3-
second consecutive intervals and compares it with the target compliance limit.
A rapid voltage change is not classified if it crosses a voltage tolerance limit ( ±10%
Un), as it would be considered a voltage dip or a temporary overvoltage.
Target Values
The maximum rate of rapid voltage changes in normally once per hour or less. For
voltage variations repeating more than once an hour, amplitude is limited by the
flicker index. The maximum rate of rapid voltage changes in variations per hour can
be changed in the device via the EN50160 Advanced Setup. The target magnitude
limit of rapid voltage changes can be programmed in the device via the EN50160 PQ
Recorder setup.
Under usual operating conditions the magnitude of rapid voltage changes (once per
hour or less) should generally not exceed 5% of nominal voltage in LV networks, and
4% in MV networks. In some circumstances, like in systems where equipment