Marian Łukaniszyn

The design and development of an axial-flux ferrite magnet slotless generator for use in a small-scale wind turbine is described. The 4/4-pole single-phase machine is designed for simplicity and ease of manufacture and it consists of one slotless stator disc. The generator produces approx. 12 W at 1000 rpm with electrical efficiency of up to 46%. Because the efficiency of the machine is important, the power curve characteristics and voltage produced by the generator are investigated. The presented generator should generate sufficient output DC voltage to charge 4 to 5 batteries of 12 volt each. Finally, the finite element (FE) results are compared with measurements on a prototype. The calculated values coincide to a strong degree with the experimental results.

Continuous development of technology determines the search for new solutions in the field of electric machine design with improved electromechanical properties. In recent years, there has been an increased interest in passive and active magnetic gears. This paper presents the design, operation and performance analysis of the modified magnetic gear. The new prototype magnetic gear allows obtaining a ratio of 4:1 or 5:1. For the analyzed construction, two and three-dimensional numerical models are developed for which the series of the magnetic field calculations are carried out . The characteristics of the magnetic torque vs. angle position of the inner rotor with respect to the intermediate ring (modulation ring) and the outer rotor are determined and compared. The examples of flux density distributions for the analyzed converter construction are presented. The calculation results are verified with measurements on the prototype.

The design of a ferrite magnet generator with trapezoidal shaped permanent magnets and coils for a wind turbine is studied. Based on the 3-D finite element analysis (FEA), the electromagnetic performances of the two generator prototypes and a simple design modification for one of the axial-flux generator prototypes are analyzed. The best generator is chosen from a range of designs, where the goal is to increase the voltage generated by the 8/8 pole and a single-phase slotless machine. Experimental results from a small size prototype machine validate the 3-D FEA models presented, and hence give confidence in their use for design.