Impact of Motor Capacitance on Vehicle Electrical System Transients

2011-01-1009

04/12/2011

Event
SAE 2011 World Congress & Exhibition
Authors Abstract
Content
The electrical architecture of today's automobiles employs a significant number of fractional horsepower motors to control wipers, windows, seats, etc. The typical motors are permanent magnet DC brush-commutated motors, often referred to as BM motors. These BM motors, while simple in design, have the inherent issue of creating short-duration, high-frequency electrical noise (caused by the constant interruption, or commutation, of the motor current). This electrical noise can readily lead to radio reception interference. In order to protect against this risk, a typical solution is to install a radio frequency (RF) filter internal to the motor. This filter generally includes a high-frequency ceramic or metal film capacitor across the motor terminals that connect to the vehicle electrical system. This capacitor, which was placed to solve one electromagnetic compatibility (EMC) issue related to radiated and/or conducted RF emissions, has the potential to create a secondary EMC issue related to conducted transients. If the motor is energized via a conventional electromechanical relay and its inherent contact bounce characteristics, a significant transient current pulse can be generated on the power bus of the vehicle which can adversely impact other electronic modules. This paper will explore the performance of BM motors with capacitor-based filters, both from a radio interference and transient risk/mitigation perspective.
Meta TagsDetails
DOI
https://doi.org/10.4271/2011-01-1009
Pages
6
Citation
Seyerle, D., and Kendall, H., "Impact of Motor Capacitance on Vehicle Electrical System Transients," SAE Technical Paper 2011-01-1009, 2011, https://doi.org/10.4271/2011-01-1009.
Additional Details
Publisher
Published
Apr 12, 2011
Product Code
2011-01-1009
Content Type
Technical Paper
Language
English