A NOVEL HYBRID GENERATOR WITH AN EFFICIENT MODIFIED VOLTAGE-MULTIPLYING RECTIFIER CIRCUIT FOR LOW FREQUENCY MOTION ENERGY HARVESTING

The output voltage of micro electromagnetic generator (EMG) for energy harvesting at low frequency is ultra-low and cannot be rectified easily and efficiently. Here, we propose a novel hybrid generator with an efficient modified voltage-multiplying rectifier circuit (MVMRC) for harvesting low frequency motion energy. The hybrid generator includes an EMG and a two-phase freestanding-electret generator (FEG), one phase of which is used for control and the other phase is used for energy harvesting. The conversion efficiency of the circuit is 51.7% under the rotating speed of 400 rpm and still 18.0% at an ultra-low rotating speed of 50 rpm, at which the output voltage amplitude of EMG is only 50 mV under the matched load. This indicates that the hybrid generator can efficiently convert low frequency motion energy to electricity energy for powering electronics.