Measuring Power Factor - Errors???
Measuring Power Factor - Errors???
(OP)
In the process of measuring power factor, I wish to use a C.T. and a P.T., how do I determine the errors that these devices will introduce to the signals I am trying to measure?
What are accepted methods of measuring PF? How do I minimise these errors?
Nigel.
What are accepted methods of measuring PF? How do I minimise these errors?
Nigel.





RE: Measuring Power Factor - Errors???
CTs and PTs have their errors determined by the standards to which manufacturers manufacture them. Standards vary.
PF can be measured by a voltmeter, ammeter and wattmeter.
The worst case PF Error is given by the additions or meter errors in terms of meter accuracies. The error may be minimized by more accurate meters.
RE: Measuring Power Factor - Errors???
If harmonics are in the circuit you may want to use digital filtering once you have collected the raw data.
RE: Measuring Power Factor - Errors???
Total Power Factor will include effects of harmonics
Displacement Power Factor will include fundamental waveforms of voltage, current, and power only.
RE: Measuring Power Factor - Errors???
ANSI C12.11-compliant instrument transformers are shipped with individual ratio- and angle-correction records. Some multifunction meters allow for software modification using correction/compensation values, and an assortment of power-factor displays.
RE: Measuring Power Factor - Errors???
Thankyou all for your quick and helpful responses!
Regards, nigel.
RE: Measuring Power Factor - Errors???
A fair number of electrical standards are available for purchase as PDFs with online ordering features. It takes a little getting used to, but there’s standards.ieee.org, shop.ieee.org, ansi.org and a vendor global.ihs.com
Typing ANSI C12.11 description in to a google search field will return a description of the standard.
RE: Measuring Power Factor - Errors???
You need to use a supply that is very clean and undistorted for the capacitive measurement.
Best regards,
Mark Empson
http://www.lmphotonics.com