2015_04_16 Noise and Vibration DSA of Electrical Machines

EOMYS ENGINEERING 2014-2015

EOMYS ENGINEERINGEOMYS ENGINEERINGEOMYS ENGINEERINGEOMYS ENGINEERING

Noise Noise Noise Noise and vibration Dynamic Signal Analysis on electrical machinesand vibration Dynamic Signal Analysis on electrical machinesand vibration Dynamic Signal Analysis on electrical machinesand vibration Dynamic Signal Analysis on electrical machines

1

15/04/2015

LE BESNERAIS Jean

SOURON Quentin

www.eomys.comwww.eomys.comwww.eomys.comwww.eomys.com

EOMYS ENGINEERING 2014-2015(C) EOMYS ENGINEERING 2013-2014 2

A. EOMYS ENGINEERING

B. Why Dewesoft ?

C. Magnetic acoustic noise and vibrations in electrical machines

D. Measurement set-up

E. Acquisition software set-up

F. Post-processings

G. Conclusion

EOMYS ENGINEERING 2014-2015 3

A. EOMYS ENGINEERINGA. EOMYS ENGINEERINGA. EOMYS ENGINEERINGA. EOMYS ENGINEERING

*"Jeune Entreprise Innovante": the French government recognises that EOMYS runs significant R&D activities

Young Innovative Company* Young Innovative Company* Young Innovative Company* Young Innovative Company* created in may 2013

Located in Lille, North of France

Activities : engineering consultancyengineering consultancyengineering consultancyengineering consultancy & applied research & applied research & applied research & applied research specialized in electrical engineering

Sectors : transportation (railway, automotive, marine, aeronautics), energy (wind, hydro), industry

OverviewOverviewOverviewOverview


Analyze and solve your multi-physics technical issues multiphysics experiments (investigation, pre-certification) and simulations advanced post-processings of experimental and simulation data

sensitivity studies, technical state of the art

proposal of technical solutions and validation by tests or simulation

Improve your design process performance development, validation and integration of high performance models

development of user-specific design interfaces

formalization of design rules delivery of high-level technical trainings

Optimize your products and processes coupling with multiobjective constrained optimization methods

automation of the design process optimization of the virtual prototyping chain

Innovate technical state of the art, ideation, concept ranking and validation research consortium / co-development projects

licence granting

ServicesServicesServicesServices


fast electromagnetic and vibro-acoustic simulation of electrical machines (Matlab-based)

use of analytical, semi analytical and numerical models to reach the best compromise accuracy / speed

automated coupling with FEMM (electromagnetic) and GetDP (mechanics) modeling of all space and time harmonics

fault simulation (e.g. eccentricity, broken bar, demagnetization)

more than 100 post processing graphs

EOMYS ENGINEERING 121, rue de Chanzy 59260 Lille-Hellemmes FRANCE

see more at www.eomys.com

MANATEE softwareMANATEE softwareMANATEE softwareMANATEE software

EOMYS ENGINEERING 2014-2015

Optimal design of innovative systems permanent magnet synchronous wind generators, traction induction machines transformers and inductors

Scientific software development use of open sources (FEMM, GetDP, OpenFoam, Octave) & commercial software (Flux, Opera, Ansys, Matlab)

advanced optimization methods (multiobjective constrained genetic algorithms, space-mapping)

development and distribution of MANATEE software

Analytical, semi-analytical and numerical modelling CFD simulation coupled to thermal nodal networks, hydraulic networks

electromagnetic subdomain models, reluctance network models

structural beam element models

Experimental characterization noise and vibration measurements

thermal and electrical measurements

6

ExperienceExperienceExperienceExperience

EOMYS ENGINEERING 2014-2015EOMYS ENGINEERING 121, rue de Chanzy 59260 Lille-Hellemmes FRANCE

7

Reduction of noise & vibration in electrotechnical systems active and passive techniques in rotating electrical machines and passive components 3D electro-vibro-acoustic simulation of rotating machines (asymmetries, skewing)

modeling of magnetic forces in rotating machines magnetostriction and Maxwell force simulation (GetDP) development of hybrid simulation methods (FEM / semi-analytic)

Experimental vibroacoustic characterization advanced post processings new measuring methods of structural modes and operational deflection shapes

InternalInternalInternalInternal R&D programmeR&D programmeR&D programmeR&D programme


B. WHY DEWESOFT ?B. WHY DEWESOFT ?B. WHY DEWESOFT ?B. WHY DEWESOFT ?

A multiphysic acquisition software suitable for multiphysics consulting activities of EOMYS (electrical engineering, thermics, vibro-acoustics, etc.)

A flexible software suitable for both investigation tests and pre-certification tests

An acquisition system suitable for both low frequency (ex: temperature) and high frequency (ex: noise)

A light-weight acquisition module suitable for field measurements

A cost-competitive solution


C. C. C. C. MAGNETIC MAGNETIC MAGNETIC MAGNETIC NOISE AND VIBRATIONS IN ELECTRICAL MACHINESNOISE AND VIBRATIONS IN ELECTRICAL MACHINESNOISE AND VIBRATIONS IN ELECTRICAL MACHINESNOISE AND VIBRATIONS IN ELECTRICAL MACHINES

What do we call electromagnetic acoustic noise or electrical noise ?What do we call electromagnetic acoustic noise or electrical noise ?What do we call electromagnetic acoustic noise or electrical noise ?What do we call electromagnetic acoustic noise or electrical noise ?

DefinitionDefinitionDefinitionDefinition

Magnetic noise and vibrations is defined as noise and vibrations due to magnetic forces

Magnetic forces can be defined as forces arising from the presence of a magnetic field

-> magnetic noise stops when an induction machine is current-free

Two magnetic forces exist in electrical machines: magnetostriction & Maxwell forces

Sinusoidally-fed squirrel cage induction machine during run-up ( slotting noise )

Non-sinusoidally-fed squirrel cage induction machine at starting ( PWM noise )

-> high frequency (100 to 10000 Hz), high tonality noise


from [B7]

Maxwell forces Maxwell forces Maxwell forces Maxwell forces tend to get the stator closer to the rotor

MagnetostrictionMagnetostrictionMagnetostrictionMagnetostriction forces forces forces forces tend to shrink the iron along the field lines

yokeyokeyokeyoke

slotsslotsslotsslots

teethteethteethteeth

STATOR

ROTOR


Electrical noise and vibration phenomenaElectrical noise and vibration phenomenaElectrical noise and vibration phenomenaElectrical noise and vibration phenomena

gearbox

electrical machine mount

supports

Tangential and radial magnetic force harmonics generate radial vibrations propagating to the external frame

Torque harmonics can propagate through rotor shaft as torsional vibrations, and efficiently radiated (large surface / normal vibrations) like gearbox frame or mount

Unbalance forces harmonics generate shaft bending vibrations which propagate to bearing & frame

Axial forces make endplates axial vibrations

Forced excitation + resonancesForced excitation + resonancesForced excitation + resonancesForced excitation + resonances

endplate

frameshaft


Why do electrical noise and vibrations matter ?Why do electrical noise and vibrations matter ?Why do electrical noise and vibrations matter ?Why do electrical noise and vibrations matter ?

Cost optimization -> thinner yoker -> increased vibration & noise

Skewing technique which is used to reduce noise and vibration levels degrades torque and efficiency

Electromagnetic & thermal & vibro-acoustic design have therefore strong interactions

Electromagnetics & Electromagnetics & Electromagnetics & Electromagnetics & vibroacousticsvibroacousticsvibroacousticsvibroacoustics interactionsinteractionsinteractionsinteractions

Health (e.g. in industry): lower the exposure to acoustic noise level

Comfort (e.g. in transportation): increase the sound pleasantness based on psychoacoustic metrics

Security (e.g. in defense): lower the vibroacoustic signature

Robustness (e.g. in energy): lower the electromechanical fatigue

Standard requirements


time frequency f

space frequency = space order = wavenumber r

Characterization of electrical noise and vibrationCharacterization of electrical noise and vibrationCharacterization of electrical noise and vibrationCharacterization of electrical noise and vibration

r=0 r=6

harmonic origin: slotting, winding, PWM, saturation, eccentricity

wave type: pulsating Vs rotating, rotation direction

forced excitation Vs resonance

largest magnetic force occurs at f=2fs (electrical frequency) r=2p (pole pair number)


D. MEASUREMENT SETD. MEASUREMENT SETD. MEASUREMENT SETD. MEASUREMENT SET----UPUPUPUP

Dewetron SIRIUS 8 channel ACC+

B&K 1-axis radial accelerometer in the middle of the stator stack(at least 8 recommended to capture r=4 order)

PCB free field microphone 1 m away from the outer frame

Optel Thevon tachometer (1 pulse per rev)

Chauvin Arnoux current clamps

ACTIVEACTIVEACTIVEACTIVE


E. ACQUISITION SETE. ACQUISITION SETE. ACQUISITION SETE. ACQUISITION SET----UPUPUPUP

SpectrogramsSpectrogramsSpectrogramsSpectrograms

FFTs for noise (20 kHz), accelerometers (10 kHz) and current (5 kHz)

Order trackingOrder trackingOrder trackingOrder tracking

For magnetic vibrations due to slotting effects the best orders to be tracked are 2p, Zr-2p, Zr, Zr+2p (p: number of pole pairs, Zr: number of rotor slots or number of rotor poles)

-> some high rank orders are needed for high torque machines (ex: Zr=212)

For mechanical vibrations the order 1 should be also tracked

Specific set-ups are used for the best tradeoff between rpm and Hz accuracy

Tachometer setupTachometer setupTachometer setupTachometer setup

Analog tacho


Operation Deflection ShapeOperation Deflection ShapeOperation Deflection ShapeOperation Deflection Shape

Use of modal test environment of Dewesoft to visualize the stator deflection under magnetic forces

Calculation of reverberation timeCalculation of reverberation timeCalculation of reverberation timeCalculation of reverberation time

Use of Dewesoft + Matlab to obtain the reverberation time in order to estimate the direct field (electrical machine) and indirect field (room reflections) contribution to the overall sound pressure level


AAAA----weighting and third octave analysisweighting and third octave analysisweighting and third octave analysisweighting and third octave analysis

dB and dBA as a function of speed

Other tipsOther tipsOther tipsOther tips

Normalization of the noise level to the current level

Online estimation of slip in asynchronous machines using tracking filter

Current angle calculation based on 2 or 3 phase measurements

Spatiograms: 2D FFT run-ups of circumferential vibration waves

= 20()

= 1

60


F. EXPERIMENTAL RESULTSF. EXPERIMENTAL RESULTSF. EXPERIMENTAL RESULTSF. EXPERIMENTAL RESULTS

Operation deflection shape (case of a 1MW induction machine, r=1 & 2)Operation deflection shape (case of a 1MW induction machine, r=1 & 2)Operation deflection shape (case of a 1MW induction machine, r=1 & 2)Operation deflection shape (case of a 1MW induction machine, r=1 & 2)


Current spectrograms (IM, raw)Current spectrograms (IM, raw)Current spectrograms (IM, raw)Current spectrograms (IM, raw)

fundamentalslotting harmonic with dynamicrotor motion


Case of a Case of a Case of a Case of a concentrated winding concentrated winding concentrated winding concentrated winding PM synchronous machine (12 stator slots, 10 poles)PM synchronous machine (12 stator slots, 10 poles)PM synchronous machine (12 stator slots, 10 poles)PM synchronous machine (12 stator slots, 10 poles)

8 accelerometers

run-up to 2200 rpm switching frequency at 1500 Hz


Accelerometer spectrograms (raw)Accelerometer spectrograms (raw)Accelerometer spectrograms (raw)Accelerometer spectrograms (raw)


natural frequencies (vertical lines)

PWM excitationsAccelerometer spectrograms (runAccelerometer spectrograms (runAccelerometer spectrograms (runAccelerometer spectrograms (run----up)up)up)up)

slotting excitationsPWM +slotting excitations


Zoom on slotting excitations matching a mode close to 250 Hz


250 Hz natural frequency (parabola)

Order tracking Order tracking Order tracking Order tracking

Wavenumber r=2 modulated by eccentricity


SpatiogramSpatiogramSpatiogramSpatiogram: : : : spectrogram of a specific space order r

Complex value + dual side FFT


r=2p=10, f=-fswi -2fsr=2p=+10, f=fswi -2fs

same as r=-10, f=fswi+2fs

r=2, f=2fs

Spatiogram r=2

not available yet as a function of rpm


r=-2 and +2 spatiograms are the same (transposition)

r=2

r=-2


r=2

r=0


r=2

r=1

Sidebands due to eccentricities

Mechanical unbalance (rotation frequency)

First bending mode


r=2

r=3


r=4

r=2


Plot / slot interactions appear as single sided-excitation (pure rotating force waves)

Eccentricities and PWM vibrations appear as double sided excitations (modulation effects: pairs of travelling vibration waves)

Natural frequencies appear as symmetrical amplifications in double sided FFTs

The machine vibration behavior is determined by wavenumbers 1 and 2

Spatiograms based on Dewesoft Math functions are far more efficient than doing an ODS at each frequency and each speed


G. CONCLUSIONSG. CONCLUSIONSG. CONCLUSIONSG. CONCLUSIONS

Advanced rotating machine analysis applied to electrical noise & vibrations reduction

On field post-processings allow to quickly identify the physical origin of noise & vibration

Combined with internal simulations (e.g. MANATEE software) some mechanical and electromagnetic redesign possibilities can be proposed and validated

Up to 15 dB reduction has been obtained after redesignto 15 dB reduction has been obtained after redesignto 15 dB reduction has been obtained after redesignto 15 dB reduction has been obtained after redesign


Thank you for your attentionThank you for your attentionThank you for your attentionThank you for your attentionAny Any Any Any questionsquestionsquestionsquestions????

www.eomys.comwww.eomys.comwww.eomys.comwww.eomys.com

2015_04_16 Noise and Vibration DSA of Electrical Machines

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