A Seamless Mode Transfer Maximum Power Point Tracking Controller for Thermoelectric Generator Applications

A boost-cascaded-with-buck converter based power conditioning system employing a seamless mode transfer maximum power point tracking controller is proposed to maximize energy production of a thermoelectric generator while balancing the vehicle battery charging, alternator output power, and vehicle load. When a maximum power point exceeds a load demand, the proposed controller switches to a power matching mode seamlessly by a dual loop control system, which detects the input and output voltages and currents of the boost-cascaded- with-buck converter, and adjusts the commands accordingly. Both voltage and current loops are designed in frequency domain using small signal models to ensure stable operation. A mode selection and command voltage and current are determined by a digital signal processor based controller. Experimental results with dynamic source and load steps are presented to show effectiveness of the proposed approach.