June-July 2018: Pyleecan open source project, tooth modulation effect

Pyleecan project

EOMYS is launching the first open-source development project for the multiphysic design optimization of electrical machines and drives under Python. This project is called Pyleecan: Python Library for Electrical Engineering Computational Analysis.

Pyleecan project logo
Pyleecan project logo

Further details can be found in our Pyleecan article presented at ICEM 2018.

The contributors are currently discussing the architecture and the starting point of the project. A presentation email of the project will be send soon on the dedicated Pyleecan newsletter to further introduce the project.

A first meeting on Pyleecan will be held at ICEM on the evening of the 4th September 2018 to discuss the development priorities. The first deposit will be made available by EOMYS after ICEM 2018 conference, it represents a part of MANATEE proprietary software.

Third party flux import in MANATEE

MANATEE software specialized in the fast NVH analysis of e-machines include the possibility to import the airgap flux density calculated by third-party electromagnetic software. A special projection algorithm is used to correctly calculate magnetic forces at stator bore radius from the knowledge of the airgap magnetic field distribution, as shown in this CEFC publication.

MANATEE software import features of third party electromagnetic solutions
MANATEE software import features of third party electromagnetic solutions

MANATEE also includes some filtering features to only include physical flux harmonics and exclude parasitic numerical harmonics coming from meshing. Besides, the time and angular discretization quality is checked as well as its consistency with NVH requirements.

Conferences and Events

EOMYS will attend to the 11th European Conference on Python in Science (EuroScipy) in Trento, Italy, 28th of August.

EuroScipy logo

EOMYS presents two papers and holds a stand at the International Conference on Electrical Machines held in Alexandroupoli, Greece, from 3 to 6 september 2018.

Publication of the Month

The publication work of the month is:

Fang, Haiyang & Li, Dawei & Yan, Peng. (2018). Modulation Effect of Slotted Structure on Vibration Response in Electrical Machines. IEEE Transactions on Industrial Electronics. PP. 1-1. 10.1109/TIE.2018.2847639.

This publication aims at illustrating the "tooth sampling effect": the fact that stator teeth spatially sample the Maxwell stress waves, so that large wavenumbers are spatially aliased to lower wavenumbers, resulting in large vibration of the yoke. This effect demonstrates that the GCD rule should not be used as it applies to Maxwell stress waves and not to effective stress waves sampled by stator teeth.

This tooth modulation effect can be included in MANATEE software specialized in the NVH simulation of e-motors. It is especially striking for electrical machines where 2p>Zs/2: in a 10 pole 12 slot PMSM, the fundamental flux creates a large magnetic force of wavenumber r=2p=10 which is not seen as r=10 by the stator slots but as r=12-10=2. This effect has to be distinguished from the force harmonics of wavenumber r=12-10=2 resulting from stator permeance and rotor mmf interaction. It is illustrated in the following figure for both subdomain model and finite element model: one can see that the force wavenumber r=10 comes back as a force wavenumber r=2 on stator teeth.

Illustration of the slot modulation effect obtained with MANATEE software
Illustration of the slot modulation effect obtained with MANATEE software

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