A self-powered extensible P–SSHI array interface circuit with thermoelectric energy assistance for piezoelectric energy harvesting

Abstract

In this paper, a self-powered extensible parallel synchronized switch harvesting on inductor (EP-SSHI) interface is presented. The proposed interface addresses multiple piezoelectric transducers (PZTs) with arbitrary phase differences, while avoiding the conflict of accessing the single inductor simultaneously. In addition, the proposed interface enhances the voltage flipping performance of the PZT by incorporating thermoelectric energy assistance to increase its output power. Measurements demonstrate that the voltage flipping efficiency of the EP-SSHI with thermoelectric energy assistance (EP–SSHI–TEA) was increased to 53.33% with the assistance of 75 mV thermoelectric energy. Experimental results reveal that the proposed interface can effectively harvest energy from multiple PZTs with any phase difference. Compared with the conventional full bridge rectifier, the EP-SSHI achieves 3.63x power improvement and 6.42x load voltage range. Relative to other advanced circuits, the proposed interface strikes a superior balance between high output power and wide output voltage range while maintaining circuit simplicity and extensibility.