Phase comparison of high current shunts up to 100 kHz

Abstract

A comparison of the phase of existing shunts for currents between 10 A and 100 A and frequencies from 500 Hz to 100 kHz has been organized. The measurements were performed at INRIM using a first prototype of a new type of phase comparator and a step-up method for the data processing. The results of the relative measurements have shown a good repeatability, but the method for the evaluation of the reference value still needs some improvement.

Error Analysis of Improved Current‐Bridge Method for Accurate Low‐Impedance Measurement

“…The quadrature component increases proportional to frequency. This result is consistent with the frequency characteristics of the same type shunt resistor reported in the reference . Therefore, it is concluded that both in‐phase and quadrature components can be measured appropriately.…”

Wideband digital phase comparator for high current shunts

“…The sample rate, for the best time definition, is generally chosen near the maximum value allowed by the board about 1 MSamples/s; the output voltage of the shunts is digitized and the array of samples collected are shifted to a permanent data file on the hard disk. In the second part, the program analyses the burst of nominally simultaneous samples following partially a similar procedure as reported in [17].…”

“…Analysis of the measurements uncertainties was given in [17]. In this paper we report only the identification and evaluation of the contributions to the phase difference of the comparator with the enhanced version of digital phase detector.…”

Uncertainty evaluation on the absolute phase error of digitizers

“…), this effect reduces its impact because phase subtraction leads to the compensation this systematic effect. Nevertheless, the issues related with measurement of the relative phase delay between two channels of the same digitizer, or two channels of two different digitizers with synchronized sampling clocks, are faced in a number of scientific papers (Bosco et al, 2011;Crotti et al, 2017;Trinchera et al, 2017).…”

“…), this effect reduces its impact because phase subtraction leads to the compensation this systematic effect. Anyway, the issues related with measurement of the relative phase delay between two channels of the same digitizer, or two channels of two different digitizers with synchronized sampling clocks, is faced in a number of scientific papers (Bosco et al, 2011;Trinchera, Serazio and Pogliano, 2017;Crotti et al, 2017). However, there are issues in special applications, not yet addressed in scientific literature, as the measurement of the phase angles timestamped against the absolute time -used for example for Phasor Measurement Unit (PMU) -in medium voltage grid application (Sánchez-Ayala et al, 2013;Braun, Mester and André, 2016;Tang, Stenbakken and Goldstein, 2013;Georgakopoulos and Quigg, 2017;Luiso et al, 2018) or as the phase difference measurement with accuracy of the microradian -necessary for example for the calibration of Low Power Instrument Transformers (LPIT) with digital output (DLPIT) or Stand Alone Merging Units (SAMU) (Djokic and So, 2005;Juvik, 2000;Collin et al, 2018;Crotti et al, 2018;Crotti, Delle Femine et al, 2018;Mohns et al, 2017;Houtzager et al, 2016;Del Prete et al, 2018), carried out by comparison with a reference device with analog output -where the absolute phase deviation of the single channel of the used digitizer may be comparable or higher than the required accuracy.…”