Design of an Integrated Air Coil for Current Sensing

Yoshikazu Kuwabara (1) , Keiji Wada (1) , Jean-Michel Guichon (2) , Jean-Luc Schanen (2) , James Roudet (3)

1 Department of Electrical and Electronic Engineering [Tokyo]
2 G2ELab - Laboratoire de Génie Electrique de Grenoble
3 G2Elab-EP - G2Elab-Electronique de puissance

This article proposes a design procedure of an integrated air coil in a laminated bus bar for current sensing. The concept is based on an air coil inserted into the insulators inside the laminated bus bar, avoiding the use of intrusive current sensors with an additional stray inductance. First, the basic principle of the integrated current sensor is described, and the relationship between the mutual inductance and the structure of the air coil is discussed. Next, the frequency characteristic of the current sensor obtained based on an equivalent circuit is detailed, the parameters of which are derived from the sensor structure. A postprocessing method is proposed to achieve a 100-MHz frequency bandwidth. A prototype of the current sensor is designed based on the proposed design procedure, and the frequency characteristic is evaluated. The validations of the design procedure and the postprocessing method are confirmed experimentally.

Mots clés: Current sensor; frequency characteristic; laminated bus bar; postprocessing

Domaines: Electronique

Yoshikazu Kuwabara, Keiji Wada, Jean-Michel Guichon, Jean-Luc Schanen, James Roudet. Design of an Integrated Air Coil for Current Sensing. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2020, 8 (4), pp.4122--4129. ⟨10.1109/JESTPE.2020.2977102⟩. ⟨hal-03260230⟩