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Electric Vehicle NVH: Not as quiet as you thought?
21 June 2018, University of Coventry
Most OEMs have an increasing range of electric and hybrid vehicles on the market with more in the pipeline. The common misconception is that these vehicles are highly refined from the outset by the very nature of the electric propulsion systems. In fact, this is not the case, and there are many challenges related to controlling the acoustic emissions of the new technology. This one-day event will enable all those interested in electric vehicle sound quality to be appraised of how these issues have been investigated and controlled, during recent research and development programmes within the automotive industry and academia.
Overview of NVH issues and their solutions regarding electric powertrain technology – Siemens The emitted sound from electromagnetic phenomena in electrified powertrains can contain high tonal components which are considered uncomfortable to vehicle occupants. This presentation will provide a concise overview of the NVH problematics of electric powertrains together with the explanation of the occurring phenomena with aim to better predict NVH performance and the result of potential design changes early in the design cycle through a combination of analytical and physics test methodologies.
Noise Breakdown of an Electric Vehicle – Dennis de Klerk, Mueller BBM A noise breakdown of an Electric Vehicle into Powertrain, Tire and Wind Noise is discussed as well as a further study about the various noise source contributions of the electric motor and gearbox(es) in the vehicle interior.
Electromagnetically-excited Noise Mitigation Techniques of Electric Motors Used in EV/ HEV Traction Application – Jean Le Besnerais, Eomys This presentation reviews all mechanical and electrotechnical solutions to reduce acoustic noise and vibrations due to electromagnetic forces in electrified powertrains. Some of the electromagnetic noise reduction solutions are illustrated using MANATEE electromagnetic and vibroacoustic software on the example of a traction IPMSM.
“Robot, Take me to the Pub!” Sound Design for Future Electric/Autonomous Vehicles – Mark Allman-Ward, Bruel & Kjaer The requirements, challenges & opportunities to engineer a different sound environment both internally and externally for fully electric and autonomous vehicles will be discussed. These vehicles exhibit sound characteristics that have a different subjective character to existing internal combustion engine vehicles, & a soundscape that does not lend itself to brand characterisation and market targeting. The opportunity to add sound styling to these vehicles is therefore of paramount importance but also presents a novel challenge. A process to approach the task of making these new sounds is presented.
Interior noise and electric vehicles – an experimental survey – Richard Cornish, Birmingham City University A small group investigated tyre noise inside electric and IC vehicles on inner city roads and some major A roads. The methodology focussed on comparing interior noise levels over road surfaces ranging from cobblestones to good and pitted tarmac. Vehicles were also compared qualitatively. In common with other workers we found that the noise levels varied strongly with the road type. Electric vehicles were about 50% heavier than the IC vehicles, with tyre pressures about 50% higher. Except for the most expensive battery electric vehicles, we found instances of much higher interior road noise. Our conclusion is that mainstream budget EVs risk becoming unpopular in cities due to poor levels of refinement.
The afternoon will consist of 4 rotating workshops.
Introduction to the Coventry University Power Lab – Dr. Kostas Gyftakis, Coventry University The Coventry University Power Lab is a new facility used for conducting research in electric power and industry related areas dealing with electrical machines and power electronics.
Use of the NVH Vehicle Simulator in the Development Process for New Vehicle Sounds – Mark Allman-Ward, Bruel & Kjaer This session will explore how sounds, internal and external, for electric vehicles can be developed and deployed.
Addressing NVH Engineering Challenges for Hybrid & Electrical Vehicles Using Simulation Tools At Concept– Andrew McQueen, Gaurav Kumar & Emmanuel Domingues, Siemens
Laser scanning techniques for vibration assessment of electric motors– Matthew Archer, Polytec Using laser scanning technology this work shop demonstrates how the method can be applied to measuring and determining electric motor operating deflection shapes for both static and rotating parts
Sound power noise source ranking using sound intensity probes in an array – Ian Macfarlane, Microflown An array of PU sound intensity probes can be used to obtain data on a DUT in one single capture. It enables the measurement of time-varying noise sources, such as motor run- ups, and can provide a quick insight into the contributions from (sub) components to the total sound power per order or order ranges, of the DUT. In this workshop you’ll be guided through the workflow of the method, from measurement to presentation of noise ranking tables.