Electrical machines form part of our everyday life at home and in industry plants. Currently induction
machines are the backbone of the industry machine installation as these are robust, reliable and have
relatively high efficiency. However as the price of energy increases and stricter efficiency regulations
are put into place there is a need for more efficient electrical machines.
The majority of induction machines on Sasol's plants are between 2.2 kW and 22 kW. Of these, 95%
machines are connected to pump loads and 2% to fan loads. Thus the majority of the machines
operate at a constant speed. Rather than try to improve an induction machine, this project proposes the
design for a more efficient LS PMSM that can also be used in the same applications as mentioned
above. Although LS PMSMs aren’t a new concept, the demand and industry interest in this
technology has increased in recent years. Since 2000 the number of research publications with regards
to this machine has increased significantly.
The goal of this project is to gain a better understanding of these machines by designing a prototype.
The design entitles the stator and rotor. As Sasol provided the funding for the project it was decided to
design a three phase, 7.5 kW 525V, four-pole machine. During the design phase several design
techniques done by other researchers were incorporated into the prototypes. The design is done with
the aid of two FEM software packages namely FEMM and ANSYS Maxwell® and verified against
calculated values.
The final prototype is tested and compared to the predicted values determined during the design. An
industry available LS PMSM from Weg, the WQuattro is also used to compare the results of the
prototype. The prototype machine’s no-load, full load and locked rotor behaviour is tested as well as
the back-emf waveform. From the results gained the machine is validated. The machine did not
perform as predicted and further investigation into the reason is needed.
Due to the incorrect wiring of the stator and some other rotor manufacturing issues the prototype
cannot be fully validated. However it was found that several of the designed values correlated to the
measured values. Further investigation into the under performances as well as more relevant testing
and practical manufacturing method is needed. / MIng (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2014
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:nwu/oai:dspace.nwu.ac.za:10394/12264 |
| Date | January 2014 |
| Creators | Sorgdrager, Albert Johan |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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