DC/DC Converter for TEG Modules
Introduction
A huge part of the world’s energy consumption is turned into heat. Unless the heat can be used for
district heating, e.g. in a combined heat and power plant (CHP), or other heating purposes the heat is
seen as waste, as heat is not a high quality energy product. Electricity is on the other hand a high quality
energy product as it is used almost everywhere, is easy to transport, and relatively easily can be
converted into other kinds of energy, e.g. mechanic, thermal, chemic, magnetic, faradic, etc.
Thermo Electric Generators (TEG) modules have the capability to converter heat into electricity and vice
versa. A lot of research is going on in TEG module order to improve their efficiency and cost. TEG
modules just need a temperature difference in order to produce power. This makes them suitable for
many applications. An internal combustion engine has a poor efficiency and a lot of heat is therefore
produced. By placing TEG modules on the exhaust pipe of e.g. a car the produced electricity can be used
for all the electric loads, e.g. light, radio, gps, fans, etc. Thereby less power is required to drive the
generator which charges the battery of the vehicle. This will reduce the gasoline consumption of the car.
A laboratory setup of a TEG module can be seen in Figure 1.
Figure 1: Test rig of a TEG module. [Min Chen, Lasse A. Rosendahl, Thomas J. Condra, and John K. Pedersen, Numerical
Modeling of Thermoelectric Generators with Varing Material Properties in a Circuit Simulator, IEEE Transactions on Energy
Conversion, vol. 24, no. 1, March 2009].
Purpose
It will not be appropriate just to connect the TEG modules directly to an electric load as the load then
passively will determine the voltage and current of the TEG module. A DC/DC converter is therefore
needed between the TEG module and the load. Thereby the energy production of the TEG module can
be maximized and controlled. The purpose of this project is therefore to analyze, design, built, and test a
DC/DC converter for a TEG module. The DC/DC converter should have a maximum power point tracker
implemented, e.g. as in photo voltaic (PV) systems, in order to maximize the energy production.
Content
The project can include the following:
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Determination of TEG application.
Characterization of voltage, current, power and efficiency of a TEG module.
Analysis, design, construction, and test of a high efficiency DC/DC converter.
Analysis, design, implementation, and test of a maximum power point tracker in a micro
controller or digital signal processor.
Analysis, design, implementation, and test of battery charger (depend on the application).
Contact
Erik Schaltz, esc@iet.aau.dk