Temperature-based thermo-electric coupling maximum power point tracking algorithm for thermoelectric generation systems under transient conditions

Abstract

The applications of thermoelectric generators (TEGs) are expanding from stable to complex environments. Traditional maximum power point tracking (MPPT) algorithms observe the electrical characteristics of TEG, and make judgments based on historical data. In a system with transient temperature conditions, the influence of system temperature on the electrical characteristics of TEG becomes the main effect, which confuses traditional algorithms and causes misjudgment. To address this issue, this paper proposes a temperature-based thermo-electric coupling MPPT (TTEC-MPPT) algorithm that considers temperature information during TEG operation. The algorithm uses Lagrange Interpolation Polynomial to predict the temperature difference of TEG and divides the disturbance step into two parts based on the temperature and algorithm. Experimental results show that the proposed algorithm outperforms four traditional algorithms and three sets of fixed pulse width modulation (PWM) conditions in five different cases, with an average power increase of 11.9211% and 20.1128% compared to traditional algorithms and fixed PWM respectively in transient cases. By considering the effect of temperature, the TTEC-MPPT algorithm has an advantage in dealing with complex transient temperature conditions compared to existing algorithms.