The aim of this exercise is to use 2D electromagnetic FEA (finite element analysis) to design and characterise the behaviour of a surface-mount permanent magnet synchronous machine (PMSM).
engineering
Description
Introduction
The aim of this exercise is to use 2D electromagnetic FEA (finite element analysis) to design and characterise the behaviour of a surface-mount permanent magnet synchronous machine (PMSM). Finite element analysis modelling tools are able to characterise most of the machine performance properties taking into account the magnetic material’s non-linear behaviour and the geometrical details of the stator and rotor structure together with their respective material properties. The 2D nature of this modelling tool will naturally not account for any 3D effects such as skew and endwinding leakage fields. As a first approximation, the latter can be neglected if the diameter to length aspect ratio issmall, in other cases these can be accounted for through analytical relations or through 3D FEA which is considerably more computationally demanding. Within this design exercise we will neglect any 3D effects.
Using an existing design of a sinusoidal PMSM you will first need to characterise its performance
and torque producing properties, and calculate an equivalent circuit and nameplate representation of
the machine. You will also look at the magnet span and slot opening and their effect on performance.
A permanent magnet machine for a high-speed turbine is shown in Fig.1. The magnets are mounted
on the rotorsurface and retained using a non-magnetic sleeve. The 4-pole machine has a distributed,
single-layer winding arranged with 2slots per pole per phase (S/P/P) in 24 slots. The stator core is
made from silicon-steel laminations and has an effective length of 100 mm. The machine is designed
to have a rated RMS phase current of 14.142A aligned with the peak torque (90˚ load angle) and a
base speed of 1500 rpm.
