Experimental Study of Macro Fiber Composite-Magnet Energy Harvester for Self-Powered Active Magnetic Bearing Rotor Vibration Sensor

Abstract

The paper presents the design, fabrication, and characterization of an energy harvester for an active magnetic bearing (AMB) rotor vibration using a macro fiber composite (MFC) with magnetic coupling. The MFC cantilevers configuration, together with neodymium magnets, is used for the contact-free rotor radial vibration self-powered sensor. The permanent magnets attached to the rotor and to the four MFC element beams ensure the mechanical energy transfer and the MFC cantilever vibration excitation. In the proposed prototype, the MFC transducer output voltage depends on the air-gap between two magnets. This paper investigates the optimum conditions to harvest as much as possible electric energy at different clearances and rotational speeds. Furthermore, to assess the rotor vibration sensitivity, the experimental results of the MFC-magnet self-powered sensor are compared with measurements obtained using a fiber optic sensor. The maximal obtained harvesting power equals 673.47 µW for the rotor speed of 3150 rpm. Moreover, the MFC cantilever was proposed as the rotor vibration sensor. The MFC-magnet self-powered vibration sensor output was compared with the fiber optic laser sensor. The mismatched vibration amplitude for both sensors does not exceed 1 µm.