Analysis and Simulations of Eccentric Rotors of Rotating Machinery in Polar Space

This paper presents a new and precise mo del for different kinds of eccentric rotor of rotating machines based on polar signals concepts. Eccentricity faults in each static, dynamic and mixed cases cause that the non-uniform air-gap of machine be established. The applied model using polar signals for eccentric rotors have removed the usage approximations in two recent decays. Eccentricity coefficients relevance, variation of Mixed Eccentricity (ME) degree against rotating frame of rotor and deduction of Static Eccentricity (SE) and Dynamic Eccentricity (DE) cases from ME case, is including the points that have considered in this research for the first time. By defining the inverse air-gap and geometrical functions of the faulty machine and applying of winding function theory and its assuming step variations, precise analytic equations are obtained for calculation of mutual inductances. The proposed model facilitates the separation of different types of eccentricity and be able to determine the difficult computation in discrete angle domain instead of continuous angle space. Meanwhile, all of equations and simulations have done in polar domain and considering of machine inductances convergence, good agreements are achieved.