Design Guidelines for the Perturb and Observe Technique for Electromagnetic Vibration Energy Harvesters Feeding Bridge Rectifiers

The most widespread architecture of ac/dc converters for resonant electromagnetic vibration energy harvesters (REVEHs) is based on a diode bridge rectifier followed by a dc/dc converter. In order to maximize the power extraction from the harvester, the voltage at the output of the bridge rectifier must be regulated by a maximum power point tracking (MPPT) algorithm. This paper is focused on the optimization of the perturb and observe (P&O) MPPT technique for REVEHs. A complete set of general guidelines leading to the proper choice of the values of the two most important parameters of this MPPT technique is provided and experimentally validated. It is experimentally confirmed that if the P&O MPPT technique is not properly and carefully customized to the particular REVEH application of interest, it may lead to very poor performance of the system.