SPICE Modeling of Electrostatic Energy Harvester for Optimal Load Resistance Analysis

Abstract

This paper presents an equivalent circuit model of an electrostatic energy harvester for a SPICE circuit simulator. The output power and impedance of the proposed model are approximated by using a simplified model of a voltage-controlled capacitor. The relationship between the capacitance and the electrode position is calculated by FEM analysis by taking the fringing effect into account; this relationship is applied to a sub-circuit model for the SPICE simulator. Further, the results of this study show that the output waveform and the optimal resistance obtained using the SPICE simulator correspond with the measurement results. In addition, the operation of a harvesting system connected with a commercially available power management IC is demonstrated.