Analysis of Bi-Te Based Thermoelectric Modules Connected to Square Series–Parallel Configuration with Isolated Power Electronics Converter for DC Micro-grid Applications

This research paper offers a thermoelectric energy harvesting system that makes use of the heat generated within the stator windings of a wind generator in the operation of a 1.25 MW wind turbine. A single thermoelectric generator can generate only lower power. To deliver higher output power, the Bi-Te based thermoelectric modules (TEMs) may be associated as an array. The square series–parallel configuration is adopted in this work owing to the advantage of unaffected internal resistance value for any quantity of TEMs. The power generated by the TEMs is unsteady owing to irregular wind velocity. Therefore, a power converter is desired before the load. The proposed energy harvesting system makes use of an isolated converter that has the benefits of better efficiency, higher voltage gain, and ability for supplying a DC micro-grid system. Furthermore, a maximum power point tracking (MPPT) is required, since no matching exists between the total internal resistance of modules and load resistance. In this work, the incremental conductance MPPT technique is used to track the maximum power at every instant of time. The performance of the proposed isolated converter has been compared with other similar converters and the results obtained are tabulated to prove the effectiveness. From the acquired experimental results, it is observed that the proposed system produces a voltage gain of 29, steadier output power during the dynamics of load and efficiency of 91.35% at a wind velocity of 12.9 m/s.