Analysis of Electrostatic Energy Harvesters Electrically Configured as Bennet’s Doublers

摘要

This paper explores electrostatic vibration energy harvesters with power electronic interfaces that configure them as Bennet’s doubler. We focus on in-plane overlap generators and consider challenges arising from small capacitance variations due to parasitic capacitances and the influence of diode parameters, such as reverse current and p-n junction capacitance, on system performance. The average charging current and initial bias voltage can be estimated from simulation results. The dependence of the minimum initial voltage on the storage capacitance is determined. When delivering energy into a storage capacitor, the voltage ultimately saturates due to the electromechanical coupling and its value depends on input acceleration, drive frequency, mechanical quality factor, and diode losses. The minimum required initial bias is about ten mVs and can be accomplished by choosing the value of the storage capacitor and utilizing diode-configured transistors in integrated circuits.