Thermoelectric energy harvester: Design considerations for a bearing node

This article presents fundamental design considerations of the thermoelectric harvester to be used in applications for machine condition monitoring or condition-based maintenance. The power to be harvested is the thermal power loss of the bearing. The aim of the harvester is to maintain the energy neutral operation. By the numerical analysis of the system equivalent model, the pulse width of the associated sensor active state is analyzed together with the power capacity of the harvester and its operation cycle length. The article contains an analysis of the influence of design parameters onto the system performance. The assumed design variables are thermal resistances of the heat sink, insulating partition, and the number of thermoelectric modules. The electrical circuitry is described by the energy buffer capacitance, sensor active state duration, and equivalent resistance of the adjoined circuitry during the passive and active states. The continuous and burst modes of operation are taken into consideration. The preliminary experimental proof of the concept is presented as well.