Abstract
This thesis is a report on the research and Micrographics. development to design a test rig for the identification of the dynamic coefficients of a radial magnetic bearing. The test rig development is intended for dynamic coefficient observation for a range of operating conditions that are a function of rotor speed and temperature. A linear model was used in this study. The coefficients observed are the proportionality constants of the magnetic bearing force to the relative positions, currents, and their derivatives. The identification is done by means of frequency excitation. Regression analysis is performed to extract the coefficients from the Fourier Transform of the experimental data. This specific study employs a homopolar magnetic bearing with electromagnetic bias coil. The test rig development requires vibration and thermal analyses. The thesis describes the analysis procedures and their effects on the final design. Two approaches were employed for vibration analysis, the transfer matrix method and the finite element method. The transfer matrix method is used to predict the critical speed of the rotor. The finite element method is used to predict the frequency response of the designed rig. Thermal analysis is used to predict the energy required to achieve the desired temperature on purpose. The finite element model is used to predict the thermal expansion of the rotor and bearing. Finally, the experimental setup is designed using a computer data acquisition system to obtain an integrated testing system.
Rahtika, I Putu Gede Sopan (1998). The design of a test rig for the identification of dynamic coefficients of a high temperature magnetic bearing. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1998 -THESIS -R348.