Design, Testing and Analysis of an Anti-Phase Electromagnetic Hydro Generator for Self-Powered Sensors

Abstract

This study proposes a novel anti-phase electromagnetic hydro generator for a larger power generation. The design consists of two waters wheels where conducting coils were fixed onto one wheel and permanent magnets were attached to the other wheel. Both wheels were made to rotate in an anti-phase motion relative to each other by supplying two water sources at different locations to increase the relative speed between the magnets and the coils. The generator was fabricated, assembled and tested experimentally, demonstrating a 70.1% larger voltage output than a conventional generator. A theoretical model was provided and was seen to agree well with the experimental measurements. However, due to the resistance from the slip ring, the water wheel with the coils attached displayed a relatively lower rotation speed compared to the other wheel. This caused the generator to exhibit a lower mechanical efficiency than the conventional generator. On the other hand, it demonstrated a higher electrical efficiency due to the larger power generated. In terms of overall efficiency, the anti-phase generator has a smaller efficiency at lower flow rates but a higher efficiency at flow rates larger than 3.7 L/min. Finally, the anti-phase generator proved to be superior to the conventional generator in terms of power density, recording a maximum value of 50.6 × 10−3 mW/cm3.