An MPTD-Specialized MPPT Algorithm Used for a Novel Medium-Power Thermoelectric System

Abstract

This article proposes a portable thermoelectric canteen system used for generating electricity while heating. A new step-shape bottom is designed, helping the canteen to be more evenly heated. The proposed canteen is a medium power and temperature difference (MPTD) system, whose main challenge is to keep system always operate at the maximum power point (MPP) when the temperature changes fast. To tackle this problem, this article proposed a new algorithm structure considered the transient response of the current. When an abnormal change in the current is obtained, X is multiplied with the voltage at time t, helping the operation point to relocate near the MPP quickly. The new algorithm structure can be applied with most existing thermoelectric maximum power point tracking (MPPT) algorithms, increasing the tracking efficiency. Furthermore, this article proposes an MPTD-specialized MPPT algorithm based on the new structure. The new algorithm uses the derivative of the power with respect to voltage and current to multiply the reference step S. When the temperature difference is 38 °C, the highest power of 0.7469 V and 70.0667 mW, respectively, can be achieved through the MPTD-specialized method. The tracking efficiency is 42.51% higher compared with the classic perturb & observe (P&O) algorithm.