High‐Efficiency Energy Management Circuit Combining Synchronized Switch Harvesting on Inductor Rectifier and Impedance Matching for Impact‐Type Piezoelectric Energy Harvester

Abstract

To improve the output power of impact‐type piezoelectric energy harvesters (IPEHs), a high‐efficiency energy management circuit combining a self‐powered synchronized switch harvesting on inductor (SP‐SSHI) rectifier and an alternative impedance matching circuit is proposed. The SP‐SSHI rectifier eliminates the effect of inherent capacitance of IPEH through LC oscillation and enhances the output power. The alternative impedance matching circuit provides two optimal load resistances for different periods of IPEHs to increase the harvested power. Furthermore, to decrease the power dissipation, the proposed circuit is activated only when the output power of IPEH is sufficiently high and the SSHI is active. A control chip of the proposed circuit is designed and fabricated in a 0.18 μm complementary metal‐oxide semiconductor process. The proposed circuit is applied for a microwind IPEH, and the peak figure of merit and efficiency are 3.68 and 90.4%, at the wind speed of 1.46 m s−1, respectively. The results indicate a significant improvement in output power and harvesting efficiency of the proposed IPEH‐specialized circuit. When a flame sensor (USEQFSEA22L80) is powered by the microwind energy harvesting system, the proposed circuit increases operating time of the sensor as 4.6 times, as compared with the traditional impedance matching circuit.