Open Circuit Voltage Based MPPT Tracing For Thermoelectric Generator Fed Non-Inverting Synchronous Buck-Boost Derived Converter – Part II (Hardware Studies)

Thermoelectric generator [TEG] devices are advantageous technique to extract the waste heat. This works based on the principle of See-beck effect, where an electromotive force will be generated when the junction of two dissimilar metals are experience a temperature difference. The overall efficiency of these modules are low, but advantages of being small, lightweight and this is easy to maintenance free, make it an attractive addition to applications where energy per unit weight or size is a primary factor. Among the key problems is obtaining a consistent voltage to power devices which depend on a consistent voltage more than maximum power. The open circuit voltage (Voc) based on MPPT algorithm is proposed here and this is well suitable for the linear electrical characteristic of the TEGs model. This experiment goal is to evaluate the thermoelectric (TEG) modules performance when connected to a non-inverting synchronizes buck- boost convertor, taking into account of this: input and output voltage, current and power, as well as convertor efficiency against various temperature differences. The experimental trial rig is using TEG module connected in series to a 0.4-5V to 5V buck-boost convertor. The hot side of the TEG module are heated via a heating blocks while the cold side are cooled by using water cooling blocks respectively. The experimental Testing is  showed that at a temperature difference of 72˚c, the input voltage and current of 1.78V and 0.79A are increased and reduced respectively to 4.16V and 0.16A.  At a temperature variance of 145˚c, the input voltage and current of 3.09V and 0.79A are raised and reduced respectively to 5.15V and 0.67A. From this test is also noted that the overall efficiency of the proposed converter increases along with temperature variance, ranging from 64% at 72˚c to 98% at 145˚c. The conversion procedure is also more efficient in case of the input voltage is near to the preferred output voltage.