Design and performance of piezoelectric energy output promotion system for road

Piezoelectric power devices have become the mainstream technology for road piezoelectric energy harvesting due to the good energy gathering ability and road adaptability. However, due to the non-uniform fabrication of internal parallel energy harvesters and the uneven rolling of loads, their electrical conflict leads to the power performance still need to be improved. This paper presents an energy promotion system suitable for road piezoelectric micro-energy characteristics, which alleviates the energy return conflict caused by inconsistent voltages and improves its overall power performance. First, the electrical performance of a cantilever-type device is tested, whose energy promotion effect is preliminarily verified. Subsequently, the promotion effect and stability are further evaluated based on electrical output of a stacked-type device commonly used on road. The results indicate that the output voltage and power of cantilever-type and stacked-type device are both improved, the maximum output voltage reaches 128 V with improvement rate of 104%–181%. And the effect of Type-II system is better than that of Type-I, the output power reaches 208 mW with improvement rate of 93%, which is more suitable for road energy collection. This work enables the technology to collect energy more efficiently under random, discontinuous, and uneven actual road traffic conditions.