Nyhetsflöde

Dear students,

You are invited to attend the following MSc project presentation:

Title: "Design of a Synchronous Reluctance Motor Assisted with Permanent Magnets for Pump Applications"

Student: ADRIAN ORTEGA DULANTO

Project carried out at: Xylem

Supervisor: Dr Tanja Hedberg

Examiner: Docent Juliette Soulard

Time and venue: Monday, 30^th of March, 13.30 (obs!), seminar room, Teknikringen 33

Opponent: Celia Carvajal Almendros

Welcome!

Abstract:

This Master thesis focuses on the design of a high efficiency Permanent-Magnet-Assisted

Synchronous Reluctance Motor (PMASynRM) intended for pump applications. The new motor is

designed to replace an existing Induction Motor (IM) in a pump product.

The basic principles of SynRM, and PMASynRM Motors and a good analytical model were

introduced. Due to the complexity and high non-linearity of this specific electrical machine, Finite

Element Method (FEM) and an analytical model were combined. First, a parameter sensitivity

analysis was carried out with the software SPEED. However, SPEED does not give appropriate

results for the sensitivity analysis of the distance from the shaft to the first barrier, and in this

case, the FEM software FLUX was used instead. Using FEM as well, the risk of demagnetization

of the magnets was controlled for the nominal current and for overload conditions. Furthermore,

some conclusions were drawn in terms of the losses, and efficiency for the selected design. The

design fulfills the required efficiency placing either ferrite or neodymium iron bore magnets in

the rotor barriers. However, if ferrite magnets are employed, the maximum current should be

controlled to avoid demagnetization.

Finally, a ferrite PMASynRM prototype was built and tested in the lab. The simulation results as

well as the measurement of other possible technologies including IM and Line Start Permanent

Magnets (LSPM) machine were compared with the measurements of the prototype in terms of

efficiency, power factor and cost. It is concluded that the designed PMASynRM is a good

alternative as it surpassed the required efficiency and the results from the simulation were close

to the test measurements.

Keywords: Demagnetization study, efficiency, FEM, parametric study, Permanent-Magnet

Assisted Synchronous Reluctance Motor, prototype.

Dear students,

You are invited to attend the following MSc project presentation:

Title: "Impact of Converter Modulation Strategies on the Losses in a Traction Motor"

Student: EMIL FJÄLLSTRÖM

Project carried out at: Bombardier Transportation

Supervisor and examiner: Dr Florence Meier and Docent Juliette Soulard

Time and venue: Friday, 16^th of January, 10.00, SMALL conference room, Teknikringen 33

Welcome!

Abstract:

With an increased demand on high-efficiency electrical machines in traction applications, better understanding

in the losses induced by the converter is needed. The harmonic losses from the converter are

non-negligible part of the total losses in an induction machine, and these harmonic losses have been

studied here with a focus on iron, skin-effect and proximity losses. The main goal of the thesis is to

advise how the modulation method can be changed to lower these time harmonic losses in an induction

machine. A model of the induction machine was created in the FEM(Finite Element Method) software.

The modulation method at higher operation is square-wave modulation, this is due to that maximum

fundamental voltage has been reached. At lower operation, pulse width modulation are used, and the

switching frequency can be increased to lower the time harmonics losses in the motor.

The iron, the proximity and the skin-effect losses were simulated in the FLUX model with different

modulation method to analyze the time harmonic losses due to respective phenomena. The iron losses

simulated in FLUX can only present in which magnitude the losses are and cannot be seen as accurate.

The proximity phenomena gives rise to a distinct increase of resistive losses in the conductor closest to

the air gap in the stator winding. The skin-effect phenomena affects the losses at square-wave modulation

of high frequencies mostly as the time harmonics are larger and of low order.

Keywords: Induction Machine, FEM, FLUX