Application of fuzzy logic-based MPPT technique for harvesting the heat energy dissipated by the wind generator stator windings to power single-phase AC grid systems

The proposed research work investigates a thermoelectric energy harvester system for generating electricity from waste heat dissipated through the wind generator stator windings to feed a single-phase AC grid. Since the wind velocity is changing at every instant, a dynamic analysis is carried out under varying temperature conditions. A single thermoelectric module (TEM) can generate low power in the range of a few watts. To increase the power, the TEMs can be connected in square series–parallel configuration, as it has the benefit of non-varying internal resistance value. To operate the TEMs at maximum power under varying temperature conditions, the maximum power point tracking (MPPT) needs to be carried out to match the internal resistance of the TEM array with the load resistance. A fuzzy logic-based MPPT technique is employed during this work, in view that it is adaptive, robust and respond rapidly under varying temperature conditions. The change in accuracy of fuzzy logic-based MPPT controller in terms of maximum power point is found to be 95.18% to 99.24%. To feed the generated power to the single-phase AC grid, a DC–DC boost converter with controller and inverter is essential. A proportional integral (PI) controller is simple to implement and can provide an inverter with a constant DC voltage. A sine pulse width modulation (SPWM) inverter is employed in this work that has the capability of producing an appropriate voltage and frequency for interconnecting the system to AC grid. The entire system was developed and analysed using MATLAB-Simulink.