New MPPT algorithm based on indirect open circuit voltage and short circuit current detection for thermoelectric generators

Abstract

This paper presents a new maximum power point tracking (MPPT) algorithm for thermoelectric generators (TEG). The proposed method is based on implementing an innovative way for indirect detection of the open circuit voltage and short circuit current, which will be used to directly steer the TEG interface converter to the MPP in very small number of steps. The proposed algorithm uses two modes of operation, namely perturb and observe (P&O) mode, in which, a fine-tuning to the MPP is taking place with fine step size. The second mode of operation is the transient mode, in which the TEG shifts its operating point due to a change in the temperature gradient through the structure. During this mode, the open circuit voltage and short circuit current of the TEG are estimated indirectly without the need to disconnect the converter, and the estimated variables are used to move the operating point directly to the vicinity of the targeted MPP, where the P&O mode is activated again for fine-tuning.