Design of permanent magnet synchronous generators for wave power generation

Abstract

In this paper, a design method for ocean wave permanent magnet synchronous generator(PMSG)is proposed with new performance criteria to obtain better output performance at the cost of less permanent magnet material. Besides, a simple equivalent analytical geometry method is put forward to calculate the sizes of permanent magnets. Based on geometric and electromagnetic models, four types of rotor structures are compared, i.e., embedded, tangential, tile surface mount and convex surface mount structures. The designs and comparisons of machine are performed with the same permanent magnet volume. Moreover, the influences of mechanical pole-arc coefficient of tile surface mount PMSG on electrical efficiency, output power, material corrosion, core loss, and torque ripple are investigated. Finite-element analysis method is applied to verify the results using Ansoft/Maxwell.

Keywords

analytical geometry method / mechanical pole-arc coefficient / ocean wave power generation / permanent magnet synchronous generator

References

[1] Halamay D A, Brekken T K A, Simmons A, et al. Reserve requirement impacts of large-scale integration of wind, solar, and ocean wave power generation[J]. IEEE Transactions on Sustainable Energy, 2011, 2(3): 321-328.

[2] Trainer T. The limits to solar thermal electricity[J]. Energy Policy, 2014, 73: 57-64.

[3] Jiang L, Chi Y, Qin H, et al. Wind energy in China[J]. IEEE Power and Energy Magazine, 2011, 9(6): 36-46.

[4] Vining J G, Muetze A. Economic factors and incentives for ocean wave energy conversion[J]. IEEE Transactions on Industry Applications, 2009, 45(2): 547-554.

[5] Hamilton R J. DC motor brush life[J]. IEEE Transactions on Industry Applications, 2000, 36(6): 1682-1687.

[6] Johan K S, Havar F O, Magne R. Wear rates and current distribution of carbon brushes on steel slip rings[J]. IEEE Transactions on Energy Conversion, 2009, 24(4): 835-840.

[7] Dorrell D G, Hsieh M-F, Popescu M, et al. A review of the design issues and techniques for radial-flux brushless surface and internal rare-earth permanent-magnet motors[J]. IEEE Transactions on Industrial Electronics, 2011, 58(9): 3741-3757.

[8] Monica C, Santiago A, Juan C B. Control of permanentmagnet generators applied to variable-speed wind-energy systems connected to the grid[J]. IEEE Transactions on Energy Conversion, 2006, 21(1): 130-135.

[9] Xia C, Chen Z, Shi T, et al. Cogging torque modeling and analyzing for surface-mounted permanent magnet machines with auxiliary slots[J]. IEEE Transactions on Magnetics, 2013, 49(9): 5112-5123.

[10] Ngu S S, Dorrell D G, Cossar C. Design and operation of very slow speed generators for a Bristol cylinder sea wave generating device[J]. IEEE Transactions on Industry Applications, 2014, 50(4): 2749-2759.

[11] Polinder H, Damen M E C, Gardner F. Linear PM generator system for wave energy conversion in the AWS[J]. IEEE Transactions on Energy Conversion, 2004, 19(3): 583-589.

[12] Liu C, Yu H, Hu M, et al. Detent force reduction in permanent magnet tubular linear generator for direct-driver wave energy conversion[J]. IEEE Transactions on Magnetics, 2013, 49(5): 1913-1916.

[13] Ratanak S, Asher S, Ted S, et al. Development of PTO-Sim: A power performance module for the open-source wave energy converter code WEC-Sim[C]. Proceedings of the ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering, 2015.

[14] Dara L O, Anthony W L. Generator selection and comparative performance in offshore oscillating water column ocean wave energy converters[J]. IEEE Transactions on Energy Conversion, 2011, 26(2): 603-614.

[15] Fang H, Cheng J, Ren Yongqin. Force analysis of float-type wave energy converter[J]. Journal of Tianjin University(Science and Technology), 2014, 47(5): 446-451.

[16] Huang Jinghua. Study on Wave Energy Utilization Device with the Combination of Oscillation Buoy and Hydraulic System[D]. North China Electric Power University, 2012.