A custom designed modular, scalable test system for an efficient performance evaluation of thermoelectric devices

Abstract

• A modular, scalable test rig capable of evaluating unicouple, devices and modules. • Ability to handle most thermoelectric (TE) performance evaluation criterion’s including real-world endurance high temperature thermal cycling, thermal soaking and identifying defective devices is demonstrated. • Evaluated three different TE systems viz. Bismuth Telluride, Skutterudites and Half Heusler alloys across different temperature gradients. • Single software platform interacting with DAQ with special features like automatic temperature stability control, high vacuum control, inert gas purging to minimize high temperature oxidation/sublimation of TE device. Reliable and efficient performance evaluation of thermoelectric (TE) elements and devices is critical for developing high performance and robust thermoelectric generator. Due to the inherent thermomechanical coupling, testing thermometric devices is a challenge and requires design of customized test rigs for a thorough evaluation. This article discusses design and development of a modular, scalable customized test rig for performance evaluation of TE devices of different proportions. Various standard TE specifications like harvested power, specific power, instantaneous device resistance, power–current relationships, device efficiency/competence measured against time/temperature difference can be readily evaluated. Further, the test rig is also employed for mimicking real-world endurance thermal cycling tests, high temperature thermal soaking and using measured data to potentially identifying defective devices which have not been addressed in detail before. All these test results together can help determine the effectiveness of TE materials in an actual real world application setting. The scalability and robustness aspects of the proposed test rig is demonstrated by evaluating three different classes of TE systems viz. Bismuth Telluride, Skutterudites and Half Heusler alloys across different temperature gradients and various TE material/legs, devices or modules. The test is capable of handling other TE material systems, geometric configurations and temperature gradients that are not discussed in this work.