Study on electromagnetic energy transducer in ambient vibration

This study documents the design of an electromagnetic energy transducer, which is used to convert ambient vibration into electrical energy. The response of the designed energy transducer is theoretically and experimentally analysed using a simple equivalent circuit model and magnetic field simulator in low-acceleration environments. For an electromagnetic energy transducer in ambient vibration, an approximate analytical expression is derived for the extracted power across a load. The energy transducer consists of four magnets (NdFeB, N35), two I-shaped magnetic cores, two U-shaped cores made of soft ferrite material, and a coil for induced voltage. The two U-shaped magnetic cores are surrounded by a coil with an approximate 3000 turn. The energy transducer is theoretically modelled using the commercial tool, COMSOL, and is experimentally validated through electrical measurements. The relation between the acceleration of vibration and the maximum average power that can be extracted at the optimal load was also studied. The size of the electromagnetic energy transducer is 43 × 37 × 80 mm3. The energy transducer has a maximum average power of 3.24 mW at a frequency of 28 Hz and an acceleration of 0.4g, and has a maximum average power of 3.83 mW at a frequency of 31 Hz and an acceleration of 0.5g.