A Power Management Circuit for Electrical Field Energy Harvester

This paper presents a high-efficiency management circuit using a maximum power point tracking (MPPT) matching circuit for power-line electrical energy harvesting. Due to small internal capacitor of the transducer and heavy load, the traditional circuit of the electrical energy harvesting at a low working frequency of 50Hz has a low transducer efficiency, and cannot be used in both low power-line voltage and heavy load. Besides, the matching impedance varies with the charging voltage. In order to achieve maximum output power during whole charging process, an up-conversion MPPT matching circuit is developed. Higher charging power, and larger ultimate charging voltage in a powerline voltage of 4000V can be obtained by using the MPPT upconversion matching circuit. In order to drive the wireless sensor with a higher consumption power, an instantaneous discharging circuit is developed. The instantaneous discharging circuit can accumulate weak energy during a long period, and provide a higher power output in a very short time. The management circuit can drive wireless sensor with an output power of 60mW.