Two-Stage Coaxial Inductive Voltage Divider and Its Calibration Setup for Use Between 1 and 100 kHz

• Published in: IEEE transactions on instrumentation and measurement 2015-06, Vol.64 (6), p.1670-1675
• Main Authors: Beug, Marc Florian, Moser, Harald
• Format: Article
• Language: English
• Subjects: Bootstrap method; Calibration; Conductors; Frequency measurement; inductive voltage dividers (IVDs); ratio transformers; Uncertainty; Voltage control; Voltage measurement; voltage ratio calibration; Windings
• ISSN: 0018-9456; 1557-9662
• DOI: 10.1109/TIM.2014.2381731

This paper describes the development of a compact n/8 inductive voltage divider (IVD) for the use in the frequency range between 1 and 100 kHz and voltages up to 5 V. The development includes a number of additional inductive components for the bootstrap calibration setup such as a supply transformer which ensures the galvanic isolation of the calibration setup, a calibration transformer, and a detection transformer. The desired frequency and uncertainty range requires a two-stage IVD design with coaxial windings, a triaxial differential branch, and voltage controlled shields to minimize capacitive stray currents. The bootstrap calibration setup follows a special coaxial-by-design scheme, which guarantees nearly identical currents in inner and outer conductors of the coaxial connections without use of any chokes. The calibration of the IVD yielded in-phase and quadrature IVD corrections within 6 · 10 -6 and 1 · 10 -6 both with uncertainties (k = 2) below 1 · 10 -6 at 100 kHz.