August 2017: XFEMM, Root cause of noise, Webinars

Ongoing MANATEE developments

MANATEE (Magnetic Acoustic Noise Analysis Tool for Electrical Engineering) software logo

Two main developments are currently under validation for the next release:

  • Coupling with xfemm to accelerate the simulation time of MANATEE when coupled to FEMM
  • Integration of a thermal nodal network model for the fast calculation of 3D temperature fields with strong magneto-thermal coupling

Zoom on MANATEE feature

MANATEE software can be used both at design stage and after manufacturing to diagnose noise and vibration issues of electric machines. A specific how-to article reviews several MANATEE tools to identify the root cause of electromagnetically-excited noise and vibrations. One of them that is particularly useful is the automated identification of flux harmonics involved in noise generation depending on a specific topology and load condition.

Manatee model for machine SPMSM_005

For instance, in the 12s10p PMSM topology of the publication: "Analytical modelling and finite element computation of radial vibration force in fractional-slot permanent magnet brushless machines" (Zs=12 stator slots and 2p=10 poles), some magnetic force harmonics occur with wavenumber r=2 at f=14f (14 times the electrical frequency).

With MANATEE, this force harmonic can be automatically identified as being generated in open-circuit condition by the combination of two flux harmonics:

  • One at frequency 13f with wavenumber 13p=65 (13th rank of permanent magnet field harmonics)
  • One at frequency f and wavenumber p-6Zs=-67.

By multiplying these two flux waves, a Maxwell stress wave of wavenumber r=65-67=-2 is obtained (elliptical force) at f=13f+f=14f.

Conferences and Events

EOMYS will present two webinars at the Motor Academy of Leonardo Energy:

Leonardo energy logo

EOMYS attends to ISEF (International Symposium on Electromagnetic Fields) 2017 held in Lodz, Poland on 14-16 september 2017 with an article entitled "Effect of the load angle on radial and tangential magnetic forces in Surface Permanent Magnet Synchronous Machines".

International Symposium on Electromagnetic Fields 2017

Publication of the Month

The publication work of the month is:

S. Wu, S. Zuo, X. Wu, F. Lin, H. Zhong and Y. Zhang, "Vibroacoustic Prediction and Mechanism Analysis of Claw Pole Alternators," in IEEE Transactions on Industrial Electronics, vol. 64, no. 6, pp. 4463-4473, June 2017. doi: 10.1109/TIE.2016.2645502

Electromagnetically-excited noise can dominate the NVH behavior of claw-pole alternators. Although their geometry in three-dimensional, the main vibroacoustic behaviour of the electrical machine under radial flux and radial magnetic pressure can be calculated using simple 2D electromagnetic models such as permeance / magnetomotive force models, or even subdomain models. In particular, the excitation of the breathing modes r=0 and elliptical mode r=p by slot/pole excitations can be considered. MANATEE v1.06.03 does not include yet the electromagnetic modeling of claw pole alternators, but the development effort is limited so it can be added quickly upon request.

Email version archive

You can find the email equivalent of this newsletter in our archives.

Read more