Real-world evaluation of a self-startup SSHI rectifier for piezoelectric vibration energy harvesting

- A new interface circuit is proposed for piezoelectric energy harvesters.
- The circuit can work in an increased excitation range with a startup circuitry.
- Experiments were performed using real-world vibration data instead of sine wave.
- It shows significant performance improvement compared to conventional rectifiers.

This paper presents an enhanced SSHI (synchronized switch harvesting on inductor) rectifier with startup circuit and representative environment validation using real world vibration data collected from a tram. Compared to a conventional SSHI rectifier, the proposed rectifier dynamically monitors the working status of the circuit and restarts it when necessary. The proposed rectifier is designed in a 0.35 μm HV CMOS process and its performance is experimentally evaluated. With a 500-s real-world collected vibration data, the conventional and the proposed SSHI rectifiers record average power performance improvements by 9.2× and 22× respectively, compared to a passive full-bridge rectifier. As the startup circuit helps restart the SSHI rectifier several times, it is able to extract energy in an increased excitation range and its average power output performance is 2.4× higher than a conventional SSHI rectifier.