Discover the first simulation software DeDicateD to the fast electromagnetic anD vibro-acoustic Design of electrical machines

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ELECTRo magnETiCaL moDEL

sTRuCTuRaL moDEL

aCousTiC moDEL

ELECTRiCaL moDEL

Geometry and control parameters

Magnet / current excitations

3D magnetic force distribution

Dynamic vibrations

Variable speed noise level

MANATEE® (Magnetic Acoustic Noise Analysis Tool for Electrical Engineering) is the first simulation software dedicated to the coupled electromagnetic and vibro-acoustic design of electrical machines. Besides electromagnetic performances, the variable-speed acoustic noise and vibration levels due to 3D Maxwell forces can be calculated within a few seconds up to 20 kHz, including all the structural resonances occurring during the run-up.The efficient implementation of analytical, semi-analytical and numerical multi-physics models allows reaching the best trade-offs between calculation time and accuracy during the iterative design process of electrical machines.

A fAst multiphysics softwAre…

FiGure 3: eFFect oF the rotor slot nuMber on MaxiMuM noise

FiGure 1: spectroGraM oF the acoustic noise leVel

FiGure 2: 2D FFt oF the raDial MaGnetic Forces

…with powerful post-processing And AnAlysis tools

Besides the efficient coupling of four multiphysical models, MANATEE includes some advanced post-proces-sings and more than 80 predefined visualization commands, including:• space and time waveforms,

1D and 2D Fourier Transforms• theoretical calculation of main

magnetic force harmonics (frequencies and wavenumbers)

• automated labelling of force harmonic expressions (see figure 2)

• modal participation factors at fixed speed and variable speed

• spectrograms (see figure 1) and order tracking of main magnetic forces

• harmonic removal tool and automated harmonic analysis

These tools help identifying the root causes of harmonic force generation, in order to quickly iterate and find a low-noise, low-vibration machine while achieving specified electromagnetic performances.

Moreover, some sensitivity and opti-mization studies can be carried on any input and output variables. A possible application is the minimization of the maximum acoustic noise level during a run-up as a function of• the rotor slot number in an induction

machine (see figure 3)• the pole geometry in a synchronous

machine

WFM SDM FEMcalculation time ++ + -accuracy - + ++robustness to geometry + - ++skewing ++ + -eccentricities & uneven airgap + - -saturation + - ++PWM time harmonics ++ + +faults (e.g. short- circuit, broken bar) + - -

table 1: coMparison oF electroMaGnetic MoDels aVailable in Manatee

FiGure 5: airGap raDial Flux Density Distribution

FiGure 6: FeMM MoDel oF a surFace perManent MaGnet synchronous Machine

FiGure 4: pWM stator currents1. electricAl model

The electrical model of MANATEE include pwm generation models and equivalent circuits with the following features:• import of user-defined

voltage / current waveform• multiple PWM strategies

(e.g. synchronous, asynchronous, calculated angles) (see figure 4)

• accurate numerical calculation of slot leakage and skin effects suitable for any slot shape

• accurate numerical calculation of saturation effects and iron losses suitable for any lamination shape

• extended equivalent circuits to account for harmonic effects

• coupling with FEMM 1 for accurate calculation of the equivalent circuit parameters (e.g. magnet emf)

• coupling with a Matlab/Simulink® three-phase inverter model

2. electro mAgnetic model

The flux density distribution (see figure 5) can be calculated using several methods:• analytical permeance / magneto-

motive force (mmf) and winding function model (WFM)

• semi-analytical subdomain model (SDM)

• magnetostatic finite-element model (FEM) based on a coupling with the open-source FEMM 1 software (see figure 6)

As summarized in Table 1, the permeance / mmf model is a convenient way to simulate in a very short time a complex combination of physical effects such as• Pulse-Width Modulation (PWM)• saturation• rotor and stator skewing• static and dynamic eccentricities• uneven airgap• faults (e.g. short-circuit, broken bar,

demagnetization)

The subdomain models are as accurate as FEM model while achieving very short computing time; they are well adapted for simple geometries without strong non linearities.

The finite element magnetostatic model is the most accurate method and the only one suitable for non-linear electromagnetic simulation. Due to its higher calculation time, it is only recommended to simulate a single speed operating point.

The electromagnetic models of MANATEE include the following features• import of user-defined air-gap flux

density waveform• modelling of any multi-phase

winding type including fractional, integral, and user-defined windings

• fast optimized numerical algorithms• automated FEM post-processings• calculation of inductances, induced

voltage, and unbalance magnetic pull• analytical calculation of main

exciting magnetic forces frequencies and pole pair numbers

1. FEMM (Finite Element Method Magnetics) is an open-source 2D finite element software under the terms of the Aladdin Free Public License (see www.femm.info).

Do you neeD a single moDel?

any moDuLE of manaTEE Can bE CoupLED To youR own DEsign woRkfLow, anD oRDERED sEpaRaTELy.

FiGure 7: stator laMination Mesh With GetDp/GMsh

FiGure 8: MoDal basis calculateD With the Finite eleMent MoDel GetDp

FiGure 10: thirD-octaVe sounD poWer leVel spectruM

FiGure 9: cylinDrical raDiation Factor MoDel

3. structurAl model

The structural models of MANATEE include an analytical model based on an equivalent cylindrical shell accounting for teeth, winding and frame effects, and a 3D orthotropic structural model based on a coupling with GetDP finite element solver 2 (see figure 7).The mechanical FEM model is automatically built and solved from MANATEE inputs. The resulting modal basis can be visualized using Gmsh open source tool.

Besides the natural frequencies of the external frame (rotor or stator), the structural model calculates its dynamic radial deflections to be used in acoustic calculations. It includes the following features:• import of user-defined modal

parameters (damping, natural frequencies)

• calculation of static / dynamic displacements, velocity and accelerations (analytical model)

• automated meshing and coupling with FEA (GetDP 2) with different boundary conditions

• automated classification and visualization of GetDP structural modes in a user interface (see figure 8)

• Frequency Response Function calculation with GetDP

• calculation of modal participation factors at fixed speed and variable speed

• visualization of the operational deflection shapes

The analytical model gives fast results, and its limited accuracy is not an issue for variable speed applications. The FEM model takes much longer time to be solved but it is more accurate, and it can account for more effects such as cooling ducts in the yoke and special frame geometries.

4. Acoustic model

The acoustic solver of MANATEE is based on the efficient implementation of analytical cylindrical radiation factor (see figure 9) and directivity models of the external structure (rotor or stator). The evolution of the acoustic sound power and sound pressure levels during a full speed range, including field weakening effects, can be calculated within a few seconds on a standard laptop.The acoustic model includes A-weighting and third octave analysis (see figure 10).

2. GetDP is an open-source finite element solver (including 3D structural mechanics) under the terms of the Aladdin Free Public License (see http://onelab.info/wiki/GetDP).

anything missing?

ouR TEam Can impLEmEnT aDDiTionaL fEaTuREs upon REquEsT, anD HaLf a Day of sofTwaRE DEvELopmEnT is offERED wiTH a nEw manaTEE LiCEnCE.

Brussel

Lille

Köln

Amsterdam

London

Paris

2h25

3h

1h20

40 min

1h

documentAtion

MANATEE documentation includes• tutorials on different topologies• html documentation of

all MANATEE functions, inputs and outputs

• schematics and description of all MANATEE input variables

• description of all available post-processings

• validation cases of the different modules

licencing

EOMYS delivers single-user perpetual licences of MANATEE on USB dongle keys. Any new licence includes half a day of customized software development. As MANATEE is made of several modules (asynchronous & synchronous machines, coupling with FEMM, etc.), each module licence can be bought separately.For a detailed quotation, please send us an email at manatee@eomys.com.

trAinings

EOMYS can deliver customized trainings on noise and vibration due to magnetic forces, and on the application of MANATEE simulation software to the optimal electromagnetic and vibro-acoustic design of your specific electrical machine.

customer support

We provide technical support at manatee@eomys.com or by phone from Monday to Thursday, 9.30 to 12.00 and 14.00 to 16.00 at +33 (0)9 81 36 63 46.

abouT us

EOMYS ENGINEERING provides outsourced applied research and development (R&D) services specialized in the optimal design of electrotechnical systems. Its activities include engineering consultancy, technical trainings, scientific software development, and licence granting.The company has developed a strong expertise on noise and vibrations due to magnetic forces in electrical systems (e.g. electrical machines, transformers, inductors). This experience includes advanced experimental characterization, mathematical modelling and numerical simulation.

ouR vision anD vaLuEs

EOMYS is a multidisciplinary team of engineers passionate for applied R&D. It embodies an innovative approach of engineering overcoming oppositions between practice and theory, short-term and long-term thinking, analytical and numerical methodologies.The values of the company focus on • high standards and integrity• energy and flexibility• open-mindedness and creativity• respect for people and environment

REfEREnCEs

ConTaCT us

EOMYS ENGINEERING 121, rue de Chanzy 59260 Lille Hellemmes FRANCE+33 (0)981366346www.eomys.com manatee@eomys.com

© 2013-2015 EOMYS ENGINEERING SAS, EOMYS and MANATEE are registered trademarks of EOMYS ENGINEERING SAS.

Any trade names or marks used are the property of their owners and are recognized, including Matlab, Simulink, FEMM, GetDP and Octave.

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