# Comparative study of converter-fed eluctance synchronous-and induction motor system efficiencies

Loubser, Andrew Thomas (2017-12)

Thesis (MEng)--Stellenbosch University, 2017.

Thesis

ENGLISH ABSTRACT: Energy efficiency in electric motor driven systems is becoming an increasingly important topic of study. As such, this thesis deals with the comparison of the drive system efficiencies of a reluctance synchronous motor (RSM) and an induction motor (IM) based on international standards for efficiency classification. It approaches this goal through the complete design optimisation of a 5.5 kW, 50 Hz, 4-pole, 3-phase reluctance synchronous motor (RSM) with inverter losses taken into account. Analytical calculations, based in part on finite element analysis, are used to determine the drive system efficiency. A simulation model of the RSM is developed and used to generate the optimised design. Optimisation results show that by maximising drive system efficiency, the motor’s power factor is automatically improved to reduce inverter losses. The optimised RSM is built and tested alongside the IM based on the international standards, and comparisons are made regarding the performance of both motors. The results show that the RSM drive system is able to outperform the IM by a significant degree at this power level. Further conclusions regarding the optimisation model and the performance of the RSM are made, and recommendations for future studies are proposed.

AFRIKAANSE OPSOMMING: Die benuttingsgraad van elektriese motoraangedrewe stelsels word alhoemeer ’n belangrike onderwerp. As sulks handel hierdie tesis oor die vergelyking van die stelsel benuttingsgraad van ’n sinchroon reluktansiemotor (RSM) en ’n induksiemotor (IM), gebaseer op internasionale standaarde. Dit benader hierdie doel deur middel van die volledige ontwerpsoptimeering van ’n 5.5 kW, 50 Hz, 4-pool, 3-fase sinchroon reluktansiemotor, met omsetter verliese in ag geneem. Analitiese berekeninge, gedeelteliks gebaseer op eindige element metodes, word gebruik om die stelsel se benuttingsgraad vas te stel. ’n Simulasie model van die RSM is ontwikkel en gebruik om ’n geoptimeerde ontwerp te genereer. Die resultate van die optimeering wys dat deur die stelsel benuttingsgraad te maksimeer, word die arbeidsfaktor van die motor indirek geoptimeer om omsetterverliese te verminder. Die ge-optimeerde RSM is gebou en tesame die IM getoets, gebaseer op die internationale standaarde, en vergelykings word gemaak aangaande die vermo¨e van beide motors. Die resultate wys dat die RSM stelsel baie meer effektief as die IM stelsel is op hierdie drywingsvlak. Verdere afleidings aangaande die optimeeringsmodel en die werking van die RSM word gemaak, en navorsingprojekte word aanbeveel.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/102791

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