Design, Modeling and Lab Test of Electromagnetic Energy Harvester for Railway Vehicle Suspensions

To enable the smart technologies, such as the GPS, suspension active and semi-active controls and electromagnetic braking system, on the railway freight vehicles, the electricity is required and in needed. In this paper, we proposed a rack-pinion based freight train suspension energy harvester with mechanical-motion-rectifier (MMR) mechanism, to harvest the energy that usually dissipated and wasted during suspension vibration. The special mechanism with one way clutches engagement and disengagement during the working period makes the harvester convert the bi-direction suspension linear motion into a generator unidirectional rotation, which improve the transmission reliability and increase the energy harvesting efficiency. Nonlinear model of the energy harvester is established in this paper to analyze the dynamic characteristic of the freight train energy harvester and bench test are carried out to experimentally characterize the proposed energy harvester. The results show that under a certain freight vehicle suspension vibration condition, the proposed energy harvester can get a peak 292W and an average 34W power, which has a much better energy harvesting performance than any other existing energy harvesting technology used for the railway vehicles. Moreover, the proposed energy harvester can reach a 70% mechanical efficiency, which shows that the MMR’s advantage in improving the energy harvesting efficiency.