Design and optimization of a large-scale permanent magnet synchronous generator

Document Type : Article


1 Department of Electrical Engineering, Aerospace Research Institute (ARI) of Ministry of Science, Research and Technology,Tehran, Iran

2 Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran


Direct drive permanent magnet synchronous generators have numerous advantages such as improved reliability, low maintenance, long life, and developed performance characteristics. Focus of this paper is on the development of a step-by-step method for the design of a permanent magnet synchronous generator. Then the winding function method is used to model the generator and to analytically calculate its output characteristics. The analytical results of the designed generator are evaluated with the finite element analysis (FEA) results and it is demonstrated that the achieved results from both methods are well matched with the experimental measurements of the Northern Power direct-drive generator. The sensitivity analysis and the optimization based on the genetic algorithm are used to achieve an optimum generator. The optimization goal is obtaining higher efficiency and power factor with lower required permanent magnet (PM) volume and voltage regulation for the optimum machine compared to the initial design. In addition, the calculation of the voltage total harmonic distortion (THD) is presented and the optimum skew angle for the optimum generator is computed to reduce the voltage THD.


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Mehdi Alemi-Rostami was born in Behashahr,
Iran, 1980. He received the BSc degree from
Gilan University, Gilan, Iran, 1998 as well as MS
and PhD degrees from Iran University of Science
and Technology, Tehran, Iran in 2000 and 2011,
respectively, all in Power Electronics. He is currently
an Assistant Professor with the Aerospace Research
Institute (ARI), Ministry of Science, Research, and
Technology, Tehran, Iran.
Ghasem Rezazadeh was born in Freydoonkenar,
Iran in 1990. He received the BS degree in Electrical
Engineering from Shahid Beheshti University in 2012.
In 2014, he received his MSc degree from Sharif
University of Technology, Tehran, Iran. He is currently
striving to achieve a PhD degree from a co-supervision
between Sharif University of Technology and the University
of Picardie Jules Verne", Amiens, France. His
research interests include electrical machine design,
modeling, and drive.
Ramin Alipour-Sarabi was born in Sarab, Iran in
1989. He received the BSc degree from Iran University
of Science and Technology, Tehran, Iran in 2012 and
MSc degree from the Sharif University of Technology,
Tehran in 2014, where he is currently trying to obtain
a PhD degree all in Electrical Engineering. His current
research interests include power electronics and design,
optimization, and performance analysis of electrical
machines and electromagnetic sensors.
Farzad Tahami received the BS degree in Electrical
Engineering from Ferdowsi University of Mashhad,
Mashhad, Iran in 1991 and the MS and PhD degrees in
Electrical Engineering from the University of Tehran,
Tehran, Iran in 1993 and 2003, respectively. From
the year 1991 to 2004, he was with R&D Department
of Jovain Electrical Machines Corporation (JEMCO),
Iran. In 2004, he joined Sharif University of Technology,
Tehran, Iran, where he is currently an Associate
Professor. Since 2007, he has been the Chairman of the
Technical Committee of Rotating Machinery, The Iranian
National Electrotechnical Committee (INEC). Dr.
Tahami is