Novel model and maximum power tracking algorithm for thermoelectric generators operated under constant heat flux

Abstract Thermoelectric generators (TEGs) are solid-state devices used to convert heat into electricity. The use of TEGs in waste heat recovery systems offers a source of sustainable electricity, which helps to reduce emissions to the environment. Optimization of the electrical operating point of TEGs is important to improve the overall efficiency of TEG systems. Previous literature focused mostly on characterizing the maximum power point (MPP) of TEGs when operating at constant temperature difference. However, in most practical applications TEGs operate under constant or limited heat conditions. In fact, in waste heat recovery systems the amount of thermal energy is limited. This work presents a new simplified TEG model that simulates the dynamic response of the TEG systems with a good degree of accuracy. With the aid of this TEG model, power and control electronics have been designed to operate a TEG system, with limited input heat flux, at its optimum load. The control architecture is based on the perturb and observe maximum power point tracking (MPPT) technique and modified to take into consideration the thermal transient response of the TEG. A boost dc-dc converter is used to step-up the TEG voltage to 28 V for connection to an eight-cell Lithium-Ion battery. A microcontroller implements the control algorithm that drives the power converter. Experimental results show that the proposed algorithm outperforms two state-of-the-art algorithms (standard perturb and observe and fractional open-circuit) by 1.14% and 2.08%, respectively, when the TEG operates under constant heat flux.

[1]  Terry M. Tritt,et al.  Advances in thermoelectric materials research: Looking back and moving forward , 2017, Science.

[2]  S. Ben-Yaakov,et al.  Modeling and Analysis of Thermoelectric Modules , 2005, IEEE Transactions on Industry Applications.

[3]  Kai Strunz,et al.  A 20 mV Input Boost Converter With Efficient Digital Control for Thermoelectric Energy Harvesting , 2010, IEEE Journal of Solid-State Circuits.

[4]  Aldo Steinfeld,et al.  A 1kWe thermoelectric stack for geothermal power generation – Modeling and geometrical optimization , 2012 .

[5]  G. Min,et al.  Variable thermal resistor based on self-powered Peltier effect , 2008 .

[6]  Li Zhang,et al.  A Thermoelectric Generation System and Its Power Electronics Stage , 2012, Journal of Electronic Materials.

[7]  A. Montecucco,et al.  Solution to the 1-D unsteady heat conduction equation with internal Joule heat generation for thermoelectric devices , 2012 .

[8]  Chulwoo Kim,et al.  A DC–DC Boost Converter With Variation-Tolerant MPPT Technique and Efficient ZCS Circuit for Thermoelectric Energy Harvesting Applications , 2013, IEEE Transactions on Power Electronics.

[9]  Bin-Juine Huang,et al.  A thermoelectric generator using loop heat pipe and design match for maximum-power generation , 2015 .

[10]  S. M. O'Shaughnessy,et al.  Performance analysis of a prototype small scale electricity-producing biomass cooking stove , 2015 .

[11]  A. Kwasinski,et al.  Analysis of Classical Root-Finding Methods Applied to Digital Maximum Power Point Tracking for Sustainable Photovoltaic Energy Generation , 2011, IEEE Transactions on Power Electronics.

[12]  Andrea Montecucco,et al.  Accurate simulation of thermoelectric power generating systems , 2014 .

[13]  Eftichios Koutroulis,et al.  A simple maximum power point tracker for thermoelectric generators , 2016 .

[14]  Jie Zhu,et al.  A comprehensive review of thermoelectric technology: materials, applications, modelling and performance improvement , 2016 .

[15]  Shixue Wang,et al.  Theoretical analysis of a thermoelectric generator using exhaust gas of vehicles as heat source , 2013 .

[16]  C. E. Kinsella,et al.  Battery Charging Considerations in Small Scale Electricity Generation from a Thermoelectric Module , 2014 .

[17]  D. Astrain,et al.  Experimental investigation of the applicability of a thermoelectric generator to recover waste heat from a combustion chamber , 2015 .

[18]  Jae-Do Park,et al.  Current-Sensorless Power Estimation and MPPT Implementation for Thermoelectric Generators , 2015, IEEE Transactions on Industrial Electronics.

[19]  Trevor Hocksun Kwan,et al.  TEG Maximum Power Point Tracking Using an Adaptive Duty Cycle Scaling Algorithm , 2017 .

[20]  A. Massaguer,et al.  Modeling analysis of longitudinal thermoelectric energy harvester in low temperature waste heat recovery applications , 2015 .

[21]  E. A. Man,et al.  Dynamic Performance of Maximum Power Point Trackers in TEG Systems Under Rapidly Changing Temperature Conditions , 2016, Journal of Electronic Materials.

[22]  Hongfei Wu,et al.  A Power Conditioning Stage Based on Analog-Circuit MPPT Control and a Superbuck Converter for Thermoelectric Generators in Spacecraft Power Systems , 2014, Journal of Electronic Materials.

[23]  Nyambayar Baatar,et al.  A Digital Coreless Maximum Power Point Tracking Circuit for Thermoelectric Generators , 2011 .

[24]  M. C. Torrecilla,et al.  Transient response of a thermoelectric generator to load steps under constant heat flux , 2018 .

[25]  Andrea Montecucco,et al.  Combined heat and power system for stoves with thermoelectric generators , 2017 .

[26]  C. E. Kinsella,et al.  Small scale electricity generation from a portable biomass cookstove: Prototype design and preliminary results , 2013 .

[27]  A. Montecucco,et al.  Constant heat characterisation and geometrical optimisation of thermoelectric generators , 2015 .