A Four-Quadrant Operation Diagram for Thermoelectric Modules in Heating–Cooling Mode and Generating Mode

Abstract

The operation of a thermoelectric module in heating-cooling mode, generating mode, and regenerating mode can be discussed in terms of power, cooling load, and current. A direct current machine in motoring mode and generating mode and an induction motor in motoring mode and regenerating mode are analogous to thermoelectric modules. Therefore, the first objective of this work is to present the four-quadrant (4-Q) operation diagram and the 4-Q equivalent circuits of thermoelectric modules in heating-cooling mode and generating mode. The second objective is to present the cooling and regenerating curves of a thermoelectric module in cooling mode and regenerating mode. The curves are composed from the cooling powers and the generating powers, the input and output current, the thermal resistance of the heat exchanger, and the different temperatures that exist between the hot and cold sides of the thermoelectric module. The methodology used to present the data involved drawing analogies between the mechanical system, the electrical system, and the thermal system; an experimental setup was also used. The experimental setup was built to test a thermoelectric module (TE 2 ) in cooling mode and regenerating mode under conditions in which it was necessary to control the different temperatures on the hot and cold sides of TE 2 . Two thermoelectric modules were used to control the temperature. The cold side was controlled by a thermoelectric module labeled TE 1 , whereas the hot side was controlled by a second thermoelectric module labeled TE 3 . The results include the power, the cooling load, and the current of the thermoelectric module, which are analogous to the torque, the power, the speed, and the slip speed of a direct current machine and an induction motor. This 4-Q operation diagram, the 4-Q equivalent circuits, and the cooling and regenerating curves of the thermoelectric module can be used to analyze the bidirectional current and to select appropriate operating conditions in the cooling and regenerating modes.

An Extensive Unified Thermo-Electric Module Characterization Method

“…Another interesting setup is proposed in [27], where both the heat produced by an electrical resistance and the cooling capacity provided by a TEM, are controlled by a proportional-integral controller. Other propose the use of one or two opportunely driven auxiliary TEMs to set the temperature gradient on the TEM under test [2,28,33]. For example, in [28], ${\mathsf{\Theta }}_{IN}$ is obtained measuring only one heat flux induced into an aluminum block with a known thermal conductivity, interposed between the module under test and an auxiliary TEM used to set the average temperature, hence requiring only three temperatures to be measured.…”