Phase/RMS Maximum Power Point Tracking for Inductive Energy Harvesting System

This paper proposes a new control algorithm to tune the input current of the AC-DC converter in an inductive energy harvester, in order to achieve maximum power transfer to a load. The conventional phase regulating method normally achieves maximum power transfer by using the input voltage as the reference. However, in a harvester the internal inductance makes measurement of input voltage inaccessible. Since the inductance is unknown, the reference of the input current is generated by a specialized phase tracking perturb and observe method to maximize the net energy output of the harvester device. The variables in this paper will be defined by: i(in) Instantaneous input current I-in RMS value (i(in)) over bar Average current over a switching period (I-in) over bar Average current over a input voltage period