Solid-state based electricity generation systems, such as thermoelectric generator (TEG) systems, promise to assist our need for a more sustainable energy future. As the name implies, a TEG converts a temperature gradient directly into electricity. If  a  load  is  connected  across  TEG  with  thermocouples, a DC current flows and its power output varies  depending  upon  the  temperature. Therefore maximum power point tracking (MPPT) is required to ensure that a TEG operates at its full potential for any environmental condition that it is subjected to. Nowadays, more research works have been concentrating on how to extract more power effectively from the TEM. Among so many MPPT schemes been proposed in thermoelectric applications, the perturbation and observation (P&O) scheme is one of the most widely used schemes due to the low-cost and ease of implementation. The drawback of the P&O MPPT technique is that, the system in thermal equilibrium electrical operating point oscillates around the MPP. Various improvements to the P&O MPPT were proposed to reduce the number of oscillations around the MPP.

This  paper  presents  the  comparative  analysis  between  Perturb & Observe (P&O) algorithm and  Perturb & Observe  based passivity for extracting the power From  thermoelectric  system. Performance  of  the  proposed  technique  is  compared  against  the  P&O one  through simulations. The obtained results confirm that the P&O/IDA-PBC MPPT has a higher power output and less power oscillation compared to P&O MPPT. It also shows that there is a significant improvement in stability around the MPP. The efficiencies of the systems with P&O/IDA-PBC MPPT were higher than 99.97%. The results show the proposed technique has much faster tracking time than the P&O has and the oscillation can be set to near zero.