Maximum Power Point Tracking Scheme for Thermoelectric Generators Based on Short-Circuit Current Method

Thermoelectric Generator (TEG), as a new energy generator, can convert heat into electricity energy directly, and maximum power point tracking (MPPT) plays a crucial role in this energy harvesting and conversion process. However, the internal resistance of TEG and maximum power point change with the external temperature. Therefore, a new short-circuit current MPPT algorithm for TEG is proposed in this paper. By analyzing the equivalent model of TEG and Boost converter, the proposed method can estimate the short-circuit current of TEG by using the instantaneous inductor current and its slope. Then the MPPT is achieved by a PI controller to regulate the root-mean-square value of the inductor current at half of the short-circuit current of TEG. Different from the traditional algorithms, the proposed method realizes MPPT without steady-state errors and oscillations, and has no negative effect on the normal operation of the converter. Finally, the simulation and experimental results show that the proposed method can effectively track the global maximum power point with only one current sensor, and the tracking process does not affect the normal operation of the main circuit, which reduces the cost and improves reliability.