Simulations on a controllable optimal voltage-based P-SSHI circuit for piezoelectric vibration energy harvesting

For piezoelectric energy harvesting, an interface circuit is very important to achieve maximum harvesting power. Parallel synchronized switch harvesting on inductor (P-SSHI) circuit has been used to enhance the harvesting efficiency, instead of standard full-bridge rectifier circuit. However, the power output of the P-SSHI circuit depends strongly on the voltage of storage capacitors (VSC). To maximize the power output, the VSC has to be controlled to realize voltage matching. In this paper, a self-powered P-SSHI circuit with controllable optimal voltage (COV-PSSHI) is proposed to solve this problem, where a self-powered electronic switch is adopted. In order to validate the improvement of the COV-PSSHI circuit, SPICE-based simulations are done under the same inputs and the results testify that the performance of the COV-PSSHI circuit is much better than that of a P-SSHI circuit.