Individual Module Maximum Power Point Tracking for a Thermoelectric Generator Systems

Thermo Electric Generator (TEG) modules are often connected in a series and/or parallel system in order to match the TEG system voltage with the load voltage. However, in order to be able to control the power production of the TEG system a DC/DC converter is inserted between the TEG system and the load. The DC/DC converter is under the control of a Maximum Power Point Tracker (MPPT) which insures that the TEG system produces the maximum possible power to the load. However, if the conditions, e.g. temperature, health, etc., of the TEG modules are different each TEG module will not produce its maximum power. The result of the system MPPT is therefore the best compromise of all the TEG modules in the system. On the other hand, if each TEG module is controlled individual, each TEG module can be operated in its maximum power point and the TEG system output power will therefore be higher. A converter with an individual MPPT is denoted iMPPT in contrast to the oMPPT which is the denotation of converters which only applies an overall MPPT. In this manuscript a converter capable of handling four TEG-modules are presented and a comparison of the system output power due to an oMPPT and iMPPT will be carried out. The implementation of the iMPPT is also presented. Simulation and experimental results will be carried out on a 4-module 80W TEG system.