Siemens 9810 Series, Руководство пользователя, Страница: 181 / 218

Measurements
Min/max recording
Your meter records new minimum and maximum data every recording interval for
a variety of values.
• Voltage and current
• kW, kVAR and kVA
• Power factor
• Frequency
• Voltage unbalance
Power quality
Your meter monitors the voltage channels, detects and records power quality
events.
The meter measures and records:
• Sag/swells: ITIC/CBEMA and SEMI curves
• Transients: 20 microseconds or longer in duration on any voltage channel
Power quality standards compliance:
• EN50160, including Flicker
• IEC 61000-4-30 Class A
• IEEE 519
The meter supports advanced power quality features:
• Disturbance Direction Detection: the meter can capture sag/swell and
transient disturbances, analyze the information and determine the direction of
the disturbance relative to the meter. Determining the source of a disturbance
more quickly and accurately helps prevent repeat occurrences and minimize
facility downtime.
• COMTRADE: the meter can save waveform data in COMmon format for
TRAnsient Data Exchange (COMTRADE) format, which is then available for
download via FTP. This is intended for use in conjunction with IEC 61850.
• Setpoint learning: You can configure your meter to learn certain disturbance-
related values, such as what constitutes a sag, swell, transient, or high or low
setpoint.
Power and power factor
The sampled measurements taken at the meter’s voltage and current inputs
provide data for calculating power and power factor.
In a balanced 3-phase alternating current (AC) power system source, the AC
voltage waveforms on the current-carrying conductors are equal but offset by one-
third of a period (a phase angle shift of 120 degrees between the three voltage
waveforms).
Power factor (PF)
Power factor (PF) is the ratio of real power (P) to apparent power (S).
PF is provided as a number between -1 and 1 or as a percentage from -100% to
100%, where the sign is determined by the convention.
PF
P
S
=
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