Modelling and simulation of a thermoelectric generator for waste heat energy recovery in Low Carbon Vehicles

This paper details the development of a thermoelectric generator (TEG) model undertaken within the Low Carbon Vehicle Technology Project (LCVTP*). The model has been developed as a tool for investigating the application of using a TEG for waste energy recovery from an automotive engine exhaust and converting it to electrical energy to offset the electrical demand on the 12V battery. The model features three main subsystems that make up the TEG system; these are the heat exchanger, the thermoelectric material and the power conditioning unit. Particular attention has been given to the power conditioning unit where two different DC-DC converter topologies namely; buck-boost and single ended primary inductor capacitor (SEPIC) have been compared for best performance. In addition, the Perturb and Observe maximum power point tracking algorithm has also been implemented and compared with a standard fixed duty cycle pulse width modulator (PWM) control. The process of developing the subsystems are briefly explained and the advantages of using the maximum power point system is demonstrated. The simulation results demonstrate that a power conditioning unit with a buck-boost converter and Perturb and Observe control is suitable for TEG systems. MATLAB/Simulink has been used for modelling and simulation of the system as well as implementation of the control strategy.