A Performance Comparison Between Synchronous and Asynchronous Electrostatic Harvesters

Synchronous electrostatic harvesters are able to deliver a higher amount of power to electronic devices compared to the asynchronous electrostatic harvesters. However, synchronous generators need a control circuit for synchronising the electrical switching events with the energy source frequency. Asynchronous electrostatic generators have the advantage of omitting this control circuit resulting in a simplified implementation and eliminates the power consumption related to this part. In this paper, the performance of a typical circuit based on each structure is explored and the optimal parameters for the asynchronous circuit are presented. It is shown mathematically and verified in simulation that the maximum generated power in the asynchronous circuit is equal to 50% of the generated power in the synchronous circuit considering the conduction losses.