Research On Self-Powered Magnetorheological Damping System

Due to the fast response, adjustable damping, simple structure, low powerconsumption, the magneto-rheological (MR) damper, as a smart damping actuator, hasmany successful applications in the domain of structural vibration control in the pasttwenty years. In recent years, researchers have found that the external powerrequirement would not only easily cause the failure of sealing and reduce the reliabilityof MR dampers but also incease the cost of power lines in some faraway regions.Therefore, the investigation into vibration energy harvesting has attracted much moreattention to avoid the dependence on the external power requirement. Howe ver, thecurrent research has many limitations such as the bulky dimension, the low energyconversion efficiency and the engineering application challenges. Consequently, it isnecessary to study the art of energy transducer from the structural vibration theorem ofMR dampers to promote the energy conversion efficiency. An electromagneticenergyharvester driven by ball screw based on the structural vibration is proposed in this study.The theoretical investigations, numerical simulations and experimental validations areconducted to verify the feasibility and availabilityof the project. The main contributionsof the dissertation are as follows.In the first place, a state of the art of the research on MR dampers is reviewed. It can beconcluded that the study of self-powered MR damper has significant values. Theresearches on vibration energy harvesting devices, self-powered MR dampers andmotion transducer are also reviewed. Their pros and cons are thoroughly evaluated.Secondly, an electromagnetic energy harvester driven by a screw is proposed inthis study. According to the requirements of application, some common energyharvesting motors and motion transducers are compared. A self-powered MR damperwith a rectifier filter circuit is designed, which is featured with a structure of two endedrod, ball screw driven, a disc permanent magnet motor.Thirdly, the magnetic circuit analysis is carried out for the disc permanent magnetmotor. The unload performance of the motor is estimated by the derivation of the basicelectromagnetic relationship under the sinusoidal excitation. The type of materials andcritical parameters of the permanent magnet motor is then determined.In addition, the simulation of the electro-mechanical energy conversionrelationship is performed on the software platform Ansys/Ansoft Maxwell3D. The finite element analysis of static and dynamic magnetic element is carried out to obtainthe unload characteristics and load characteristics after rectifier filter under thesinusoidal excitations.At last, the actual test is performed to validate the proposed MR energy harvestingdevice. After designing and fabricating a rectifier filter circuit and an energy conversiondevice, the phase voltage and load voltage of the disk permanent magnet motor ismeasured on the electromagnetic vibration table under different excitations. The testresults indicate that the energy harvested by the energy conversion device can satisfythe energy requirement of the MR damper and verify the validity of proposed scheme.