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Session:

8E - Power Quality Standards 

Date & Time:

Wednesday August 9, 2:30 PM - 4:00 PM

Paper Title:

Improved AC-DC current transfer standards from 10 mA to 100 A 

 

 

Speaker:

Dr. Torsten Funck  

CoAuthors:

Manfred Klonz, Luciana Scarioni, Ernst Keßler 

Speaker Info

Company:

Physikalisch-Technische Bundesanstalt

Department:

AG 2.12 Hertz-Bau

Address:

Bundesallee 100
Braunschweig, 38116, Germany

Phone:

49 531 592 2320

Fax:

49 531 592 2345

Email:

torsten.funck@ptb.de 

 

 

Abstract:

Improved AC-DC current transfer standards from 10 mA to 100 A Speaker: Torsten Funck, Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany, Phone +49 531 592 2320, Fax +49 531 592 2345, Email torsten.funck@ptb.de Authors: Torsten Funck, Physikalisch-Technische Bundesanstalt, Braunschweig, Germany Manfred Klonz, Physikalisch-Technische Bundesanstalt, Braunschweig, Germany Luciana Scarioni, Universidad de Carabobo, Facultad de Ciencias y Tecnologia, Departamento de Física, Valencia, Venezuela. Ernst Keßler, Institut fur Physikalische Hochtechnologie e.V. (IPHT), Jena, Germany Abstract Recent developments resulted in new planar multijunction thermal converters on quartz substrate (QPMJTC), which are now used as the basic calculable AC-DC current transfer standards with very small uncertainties [1]. To reduce the contribution of the measurement set-up to the uncertainty budget, potential driven guarding of the standard at high potential in the series connection and of the input circuit of the nanovoltmeter has been implemented. Changing the position of the standards to be compared from high to low potential does not result in a difference for the ac-dc difference anymore as it was the case in the former measurement set-up [2]. Planar multijunction thermal converters on silicon substrate (PMJTCs) are used for all standards in the scale, because of their high dynamic range allowing to reduce the number of steps required in the step-up chain. The development of new current shunts [3] at the NMI of Norway, Justervesenet (JV) gave the possibility to extend the frequency range to 1 MHz and to compare the level dependence in the step-up chain with shunts of other manufacturers used in PTB up to now. To perform ac-dc current transfer measurements up to 1 MHz a transconductance amplifier was designed to deliver precise currents of up to 1 A at frequencies from DC to1 MHz. AC shunts up to 100 A and 100 kHz are commercially available in recent years. In the step-up procedure the level dependence of the AC-DC difference of the current shunts is the most predominant contribution in the uncertainty budget especially at high current and high frequencies [2]. A single-stage current transformer for up to 100 A and 100 kHz with the ratio of 100 to 1 has been developed. The level dependence of the current transformer's ratio error was measured and calculated to be less than 5?10-6 at frequencies from 5 kHz to 100 kHz. The current transformer allowed to measure the current level dependences of the ac-dc difference of commercially available high current shunts for 30 A to 100 A. References 1. L. Scarioni, M. Klonz and T. Funck, "Quartz planar multijunction thermal converter as a new ac-dc current transfer standard up to 1 MHz," IEEE Trans. Instrum. Meas., vol. 54, pp. 799-802, April 2005. 2. M. Klonz, H. Laiz, T. Spiegel, and P. Bittel. "AC-DC Current Transfer Step-up Calibration and Uncertainty Calculation," IEEE Trans. Instrum. Meas., vol. 51, pp.1027-1034, Oct. 2002. 3. K. Lind, T. Sørsdal, and H. Slinde, "High performance AC-DC Current shunts from inexpensive components," CPEM2006 digest  

 

 

 

 

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