Energy resources are under tremendous pressure with society’s ever increasing need for electricity.
However, resources are becoming scarce and the effect of our power generation on the environment is
cause for concern. The cost of electricity is also increasing and thus the need to reduce energy
consumption is apparent. Most electrical energy generated is consumed by electric motors. Most of
these motors are induction motors because they are reliable, efficient and durable. Though these
motors are highly efficient, there is still room for improvement when the strain on electrical energy is
taken into account. Constructing motors with better efficiency can result in a reduction in energy
consumption and cost savings to the consumer.
One method of increasing a motor’s efficiency is to use permanent magnets in the construction of the
motor’s core. Permanent magnets eliminate the excitation losses experienced by induction machines,
thereby increasing the motor’s efficiency. A retrofit design is considered because of the ease of
manufacturing for motor suppliers and the ability to apply the solution to existing operating induction
machines. The prototype will lay the foundation for future optimisation strategies. The optimised
design should provide improved efficiency with a minimum effect on the motors already operating in
industry.
The design process followed uses the design principles for inductions machines and for sizing
permanent magnets. The design is then verified through the use of finite element method software
packages, FEMM and ANSYS Maxwell®, and validated by performance testing. A comparison is
drawn between the calculated results and the results determined from the performance analysis. The
retrofit design performed as expected during the testing with some discrepancies in final values
attributed to the manufacturing process. However, the efficiency is lower than designed and requires
the implementation of machine optimisation strategies. / MSc (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2015
| Identifer | oai:union.ndltd.org:NWUBOLOKA1/oai:dspace.nwu.ac.za:10394/15239 |
| Date | January 2015 |
| Creators | Garner, Karen Sharon |
| Source Sets | North-West University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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