Current-Sensorless Power Estimation and MPPT Implementation for Thermoelectric Generators

Presented is a duty-cycle-based maximum power point tracking (MPPT) scheme with current-sensorless power estimation. Conventional MPPT methods require generated power data involving direct current measurement, or disconnection of source and load for open-circuit voltage measurement. The proposed scheme avoids these disadvantages while retaining MPPT capability. This microcontroller-based approach allows for easy implementation and tuning of the MPPT algorithm to suit the characteristics of the thermoelectric generator (TEG) with respect to environmental conditions. The hysteresis voltage regulator maintains the TEG output voltage at a reference level, so that the maximum power can be extracted for the given temperature condition. The proposed MPPT energy harvesting scheme is simple and inexpensive, has a low power consumption, and can be used with various types of generators. The proposed system has been validated analytically and experimentally.