July 2016 : Fast skew optimization, Complex permeance, ICEM and EuroScipy 2016

MANATEE new features

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

A breakthrough development has been achieved in MANATEE subdomain models by the derivation of the complex relative permeance. The possibility to make the distinction between reluctant effects and field sources in an exact way for both radial and tangential airgap flux density allows a direct validation of permeance / flux linkage model. It will also allow to use the advantages of permeance-based modelling techniques in subdomain models by including the airgap asymmetries (static and dynamic eccentricities, airgap unevenness).

The figures below show three comparisons between this new method (Complex Relative Permeance or CP) and the methods already implemented in MANATEE :

  • Finite Element Method (FEM)
  • Subdomain Model (SDM)
  • Permeance MMF (WFM)

All these simulations are made on the default_machine (SCIM 36Zs28Zr6p), at synchronous speed (slip = 0) with armature field.

Radial and Tangential Airgap Flux (Femm vs subdomain vs permeance/mmf)

The next table details the relative error of each method compared to FEM :

Relative error compared to FEM

One of the main improvements is the computation time with a high number of time steps as you can see on the comparison graph below :

Computation time comparison (WFM vs SDM vs CP vs FEM)
Phasor diagrams

MANATEE’s electrical module now includes phasor diagrams for positive, negative and zero sequence decomposition in Fourier domain and unbalance study of three phase sources.

Phasor diagrams
New topologies

MANATEE v1.06.01 will also introduce a new slot shape (based on slot type 10) and trapezoidal magnets

MANATEE 1.06.01 new topologies

Zoom on MANATEE feature

MANATEE software can be used to optimize the skew pattern of rotor and stator in terms of torque ripple and electromagnetic noise and vibrations. In Permanent Magnet Synchronous Machines the optimal skew is not necessarily one stator slot pitch, and it may depend on the load state. The optimum slot or pole inclination can be found by running a sensitivity study in MANATEE. Using electromagnetic subdomain models, this study only takes a few seconds.

The following graphs show the impact of a stepped-skew rotor with 7 slices, demonstrating that the optimum skew angle is not the same for cogging torque and noise minimization.

Sensitivity study: effet of stator skew angle on the cogging torque and the noise
Sensitivity study: effet of stator skew angle on the cogging torque and the noise

EOMYS News

EOMYS will present 3 articles at ICEM 2016 :

To keep up to date to the latest trends in scientific software development, EOMYS will attend the EuroScipy conference in Erlangen. The EuroSciPy meeting is a cross-disciplinary meeting focused on the use and development of Python language in scientific research. We will be able to discuss our way of optimizing computation, organizing results, analyzing data... with other scientists in various application domains and physics.

EuroScipy logo

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