An Improved Analytical Model for Salient Pole Synchronous Machines Under General Eccentricity Fault

Abstract

Abstract-This paper develops a more precise analytical model for calculating salient pole synchronous machine (SPSM) inductances in case of general eccentricity including static, dynamic and mixed eccentricities. The developed method is based on the modified winding function approach (MWFA) which accurately considers variable air gap function and leads to pure analytical expressions of inductances. Available analytical techniques, based on MWFA, approximate the air gap function and simplify the geometrical model of SPSM, whereas, in this study, the influence of the openings between the rotor salient poles has been taken into account by using an effective form of rotor pole shoes. Using this technique, flux fringing effect is considered. By taking into account machine geometry, type of windings connection and flux fringing effect, this method is able to model most of the important features of an eccentric SPSM. The developed analytical expressions can calculate time varying inductances of SPSMs with any eccentricity type and degree in the frame of a single program. Simulation results for static eccentricity are compared with experimental tests on a laboratory generator to verify accuracy of the proposed model.

Analysis and effect of static eccentricity fault on performance indicators of a synchronous reluctance motor

“…Majority of the researchers who investigated faulty machines patronized this method. The calculations of inductances of salient-pole synchronous motor operating under eccentricity using MWFTh were done by [17,20] and [21]. Again [21] developed an analytical model that can compute the machine inductances under any kind of eccentricity.…”

“…The calculations of inductances of salient-pole synchronous motor operating under eccentricity using MWFTh were done by [17,20] and [21]. Again [21] developed an analytical model that can compute the machine inductances under any kind of eccentricity. The method was based on MWFA which took into account the variable air gap functions, the flux fringing effects, slots effects and the three-dimensional distribution of machine windings.…”

A Modified Model of Squirrel Cage Induction Machine Under General Rotor Misalignment Fault

“…This method has been applied to analyze static, dynamic and mixed eccentricity in induction and synchronous machines [7][8][9][10][11][12]. In [13], different geometrical models for the calculation of inductances of induction machines were evaluated, and the best approximation was recommended.…”