Design and Performance Analysis of Double Axial Flux Permanent Magnet Generator

Abstract

In this paper, a new permanent magnet generator structure was proposed in order to facilitate the implementation of the permanent magnet generator on small-scale renewable energy-based power generators. Detail characteristics of a double axial flux permanent magnet generator were analyzed. The proposed generator structure consisted of 2-sided rotors equipped with slots for placing permanent magnets. The stator side comprised 3 groups of coreless winding for realizing 3-phase output. Performances of the axial flux double permanent magnet generator were observed involving the output voltage, currents, and power. Two experimental scenarios have been tested to monitor the performance of the generator. In the first scenario, the loading condition which was represented by the star connection of 3 bulbs of 25 W has been considered. The rotational speed of the tested generator in this scenario was 501.9 rotation per minute (rpm). Under those loading circumstances, 3-phase sinusoidal output voltages with frequencies under 50 Hz have been monitored. Above 50 Hz operational frequency, the output voltage waveform slightly changed from sinusoidal to trapezoidal shapes. In the second scenario, the proposed generator was connected to the rectifier to form a DC system. The 45 W load has been considered in this DC scenario. Under the DC system test, 152.2 V output DC voltage, 0.1614 A current, and 24.976 W power have been monitored when the rotational speed of axial flux double permanent magnet generator was 847.9 rpm.