Performance Improvement of a Self-powered P-SSHI based Piezoelectric Energy Harvester by Tuning the Switching Delay and Inversion Factor

Abstract

Among various interfacing power management circuits for piezoelectric energy harvesters, synchronous switch harvesting on inductor (SSHI) topology is one of the most efficient approaches nowadays. In the SSHI circuit, the Switching Delay (SD) and Inversion Factor (IF) are the key factors to contribute to overall harvested power. Here, we propose a modified SSHI topology to achieve the desired SD and IF for harnessing optimized power. The modified topology is theoretically analysed, simulated and experimentally validated. The proposed circuit can tune the amplitude of SD from negative to positive (including zero) or vice versa and can also improve the inversion factor to reduce the loss from the circuit. Three combinations of bridge rectifier configurations, along with the P-SSHI block, are compared and analysed to select the best combination for the operation to maximize power output. The proposed circuit encompasses double advantages, such that it can minimize the SD by tuning $R_{NEW}$ resistor and maximize the average harvested power (AHP) by choosing the parametric values of $R_{NEW}$ along with $R_3$ resistor properly. Furthermore, an improvement of 41.3% in the AHP is obtained in experimentation for the proposed circuit compared to the existing circuit for the optimum parametric conditions.