Sensor Placement for Field Reconstruction in Rotating Electrical Machines

A method is proposed in this article to place sensors in an electrical machine in order to be able to reconstruct the magnetic field distribution. This method is based on the empirical interpolation method combined with the Maxvol technique. The results applied on a surface-mounted permanent magnet machine at no load show that the field distribution can be accurately reconstructed even when the sensor location is imposed in the airgap of the rotating machine.

I. Introduction

Being able to reconstruct the magnetic flux density distribution in an electrical machine from several local field measurements would be of great interest enabling us to estimate global and local quantities (iron losses, torque, and so on) in real time. With the development of the Internet of Things (IoT) combined with the progress in microelectronics, we can expect, in the next future, to equip electrical machines with wireless sensors of the magnetic field, temperature, and so on at low cost. The question, which arises, is then: are we able to reconstruct the field distribution in an electrical machine from a limited number of sensors and where shall we locate them?