New Behavioral Modeling for DC Motor Armatures Applied to Automotive EMC Characterization

This paper presents a high-frequency modeling method of direct current motor armatures dedicated to low-voltage automotive applications. The proposed model is based on a behavioral approach, which permits to reproduce impedance measurements. It takes into account some physical features and phenomena related to the motor armature. The influence of the skin effect in the windings, the magnetic field penetration in the core, and the armature manufacturing systematic error in the impedance evolution is considered with this model. The model was first developed from that of a basic iron core inductor and improved afterward in order to cover a high frequency range (from dc up to 1 GHz). Several identification methods were used to quantify the model parameters. Furthermore, the model was associated to a noise-current generator in order to estimate the conducted disturbances. These last ones are emitted by the motor in the RF range (100 kHz-108 MHz), knowing the operating conditions of current intensity, voltage, and speed.