An optimized self-powered P-SSHI circuit for piezoelectric energy harvesting

Abstract

Self powered energy management circuits make energy harvesting converters more efficient and more reliable. This paper presents an improvement of a self-powered parallel synchronized switch harvesting on inductor (P-SSHI) circuit for piezoelectric transducers. Two different switching techniques are evaluated, which are switching based on two MOSFETs controlled by two operational amplifiers and switching based on bipolar transistors. Simulation results show that the circuit using the switch based on bipolar transistors delivers a 19.2 times higher power comparing to the other switching technique. Optimization of this result is proposed by reducing losses in the circuit using less energy consuming components which increases the power output by more than 300% in comparison to formerly proposed solutions. The optimized circuit is designed and tested using a commercially available piezoelectric converter with and without a proof mass. Experimental results are compared to simulations made using the same excitation sources. A good agreement is found between the course of both simulation and experimental results.