Stromwandler

Details

Veröffentlichungs-Nr.

EP4752566

Anmeldetag

29. November 2024

Veröffentlichung

3. Juni 2026

Rechtsraum

EP

IPC

G01R15/18

Abstract

Current transducer (1) for measuring an alternating current in a conductor, the current transducer comprising an inductor (2) having a first connection point (4a) at a first electric potential corresponding to a first measurement voltage Va with respect to ground and a second connection point (4b) at a second electric potential corresponding to a second measurement voltage Vb with respect to ground, and a processing unit (10) connected to the first and second connection points (4a, 4b) configured to convert an induction voltage induced in the inductor by said alternating current into an output signal of the current transducer representing a measurement of the alternating current. The processing unit (10) comprises a first analog-to-digital converter (30a) connected to the first connection point (4a), a second analog-to-digital converter (30b) connected to the second connection point (4b), and a linearity compensation network (20). The linearity compensation network (20) comprises:a voltage divider (21) connected between the first and second connection points (4a, 4b) and having a mid-point (4c) at a mid-point electric potential (φmid) between the first electric potential and the second electric potential,a subtractor (27) connected to an output of the first analog-to-digital converter (30a) and an output of the second analog-to-digital converter (30b), anda mid-point voltage adjustment unit (23) connected to an output of the subtractor or outputs of the first and second analog-to-digital converters (30a, 30b), and configured to adjust the mid-point electric potential (cpmid) based on the output of the subtractor or the outputs of the first and second analog-to-digital converters (30a, 30b) to maintain absolute values of the first and second measurement voltages Va, Vb greater than an error threshold Th for an alternating current with a peak amplitude smaller than a small amplitude current threshold Th₁.

Anmelder

Firma

LEM International SA

Land

🇨🇭 Schweiz

Fachgebiete