D5.2 LF Measurements on a suitable drive train

Executive Summary

This document describes the methodology and results obtained from electromagnetic field measurements on a representative electric vehicle drive train.  A variety of configurations have been evaluated, with different combinations of torque loading and motor speed levels.

The drive train comprised a switched reluctance motor with its associated control electronics. The switched reluctance motor was a 70 kW motor running at a nominal 300 V, and was driven by a DC voltage from a wall-mounted converter through the inverter. The motor and inverter were situated in a laboratory at the motor manufacturer’s premises.

Measurements were carried out during two measurement campaigns. The first campaign concentrated on radiated emissions between 9 kHz and 30 MHz, but also included magnetic field exposure measurements using two instruments (assessing magnetic field exposure over the band 1 Hz to 400 kHz, and electric field exposure over the band 300 kHz to 40 GHz). The second campaign concentrated on time-domain measurements of cable currents and magnetic field outputs from the magnetic field exposure instrument at frequencies below 9 kHz.  These measurements were carried out at both the motor and the control end of the cable run.  The frequency spectrum of the power train emissions was also determined from the magnetic field waveforms.  The results in the second measurement campaign link the magnetic field probe outputs to the current waveforms and the DC link current.

It is discovered that this 75 kW system exceeds the magnetic field reference levels recommended for general public exposure at distances closer than 200 mm from the phase ‘C’ cable at the motor under steady-state conditions. Nonetheless, provided that some basic installation practices are followed (e.g. running the cables for each phase of the motor as close together as possible, and mounting the motor so that it is not directly between the driver and front seat passenger, for instance) it should be possible to ensure that the field levels in the passenger compartment do not exceed the field exposure recommendations.

Further experiments are also suggested to improve the understanding and the categorisation of the low frequency fields emitted by the powertrain.


>return to deliverables




>return to results


Project acronym:

Project name:
 Electrical powertrain Health Monitoring for Increased Safety of FEVs

Project reference:

Start date: 01/06/2012
End date: 28/02/2015

Sponsored by

FP7 logo