A scalable micro-power converter for multi-source piezoelectric energy harvesting applications

The paper presents a conversion scheme based on active control for harvesting power from multiple piezoelectric transducers with higher efficiency than traditional passive approaches. The use of multiple sources is often mandatory for boosting up the available output power. The proposed approach guarantees that each source operates efficiently, especially in case of irregular vibrations and heterogeneous transducers. A prototype system was developed and validated in realistic conditions: three 0.5x12.7x31.8 mm3 Q220-A4-303YB transducers from Piezo Systems of different wear conditions loaded with 20g tip masses were stimulated with the vibrations recorded in a train passenger car at 100 km/h. The converter harvested up to 142 uW@0.22g-RMS and up to 90 uW@0.11g-RMS. With the latter vibrations the extra harvested power with respect to a standard passive electronic interface was at least 41%. The converter is modular and the number of sources can be easily increased.