Optimization and AMS Modeling for Design of an Electrostatic Vibration Energy Harvester's Conditioning Circuit with an Auto-Adaptive Process to the External Vibration Changes

This paper presents an analysis and system-level design of a capacitive harvester of vibration energy composed from a mechanical resonator, capacitive transducer and a conditioning circuit based on the BUCK DC-DC converter architecture. The goal of the study is to identify optimal power performance of the system, to understand the electromechanical coupling phenomena and to propose the optimal timing of switching between charge pump and flyback circuits. To achieve the study we provided a VHDL-AMS/ELDO mixed model based on physical equations describing the resonator and transducer operation. To test different algorithms of the switching, we developed a behavioral functional model of the switch commuting between the two operation phases. We demonstrated that to guarantee an optimal power generation, switching should be driven by the internal state of the circuit. This paper provides the keys of the underlying analysis and provides a basic algorithm of the switch “intelligent” command.