A rotational vibration energy harvester for near-zero-energy applications in railway environment

The vibration in the railway environment contains a huge amount of available mechanical energy, which can be utilized as a practical power source for low-power independent distributed appliances. This paper proposed a rotational vibration energy harvester (RVEH) based on a linear cam mechanism for near-zero-energy applications in railway environment. The RVEH system mainly consists of a motion conversion mechanism (MCM) and electromagnetic generators. The motion conversion mechanism realizes the motion conversion from vibration to uni-directional rotation based on a linear cam and a one-way rectifier. The electromagnetic generators convert kinetic energy into electrical energy. The test shows that the electric outputs of the proposed RVEH is improved under vibration excitations compared with the conventional vibration energy harvester (VEH, the RVEH without a one-way rectifier). Also, the RVEH has a comparatively long duration of electric outputs after the vibration excitation, suitable for the intermittent vibration excitation input. And the RVEH can operate as a power supply, producing output characteristics of an average output power of 66 mW and a peak output power of 0.15 W, sufficient to power 155 LEDs in series or a thermometer. It is foreseeable that the RVEH is a promising self-powered solution for applications in railway environment.