PDSH 998 Measurement of circuit power factor and supply current
http://decisions.iecee.org/icons/ecblank.gif PDSH 998
Measurement of circuit power factor and supply current
General
60968(ed.1);am1;am2 & 60969(ed.1);am1;am2
Standard(s):
IEC 60968 All editions
IEC 60969 All editions
Subclause(s): General
No. Year PDSH 0998 2010
Category: LITE
Developed by: ETF5 OSM/LUM
Subject:
Measurement of circuit power factor and supply current
Key words:
- True power factor
- Supply current
- High frequency components
To be approved at the 49th CTL Plenary Meeting, in 2012
Question:
When measuring the circuit power factor and supply current of non linear load (a self-ballasted lamp), we
would like to check if there is a need to consider the frequency range of the power meter. The product in
question produced high frequency components as shown in Figure 1. The true power factor can only be
measured with power meter set to encompass these high frequencies. With the power meter’s frequency range
specified from d.c. to 25 KHz, the power meter reads a power factor of 0,880 and a current of 330 mA. As the
frequency range was extended to 50 KHz, we found the power factor is much lower compared with cos f
(power factor measured at fundamental frequency). Which value of power factor can we accept on the product
or on the manufacturer catalogue?
Decision:
In case of high harmonics and high crest factor, to get an accurate measurement, a power meter with a higher
frequency range has to be used.
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