Time-Stepping Finite-Element Analysis of Dynamic Eccentricity Fault in a Three-Phase Salient Pole Synchronous Generator

Abstract

Abstract-In this paper, two-dimensional time-stepping finiteelement (TSFE) method is performed for modeling and analyzing of a salient pole synchronous generator with different degree of dynamic eccentricity (DE) fault. TSFE analysis is used to describe the influence of DE fault on the flux distribution within the generator and no-load voltage profiles at low and high field current is obtained for healthy and faulty cases. Comparing the magnetic flux distribution of healthy and faulty generators helps to detect the influence of DE fault. Also, it can be seen at no-load condition with low excitation current, the effect of the eccentricity is considerable compared to that of the rated excitation current. Since the calculation of inductances of the machine is the most important step for fault analysis and diagnosis, the self-and mutualinductances of the stator phases and rotor windings are calculated in the eccentric generator. Double periodic phenomenon is observed in inductances profile of stator phases due to the DE fault. Finally, spectrum analysis of stator current of two generators with different design parameters is used to diagnosis the significant harmonics in the presence of DE fault.

Study of the impact of eccentricity in large synchronous generator with finite elements

“…(8). The integral contour is chosen in the middle of the air gap and is kept as far as possible from the iron parts, as already described in [7].…”

“…The unbalanced magnetic pull in a large hydro-generator in practical operation was studied in [7], using finite element methods. Dynamic eccentricity aspects were studied in [8] in a four pole synchronous generator in order to analyze its impact on flux line distribution and profile inductance. A method to detect static and dynamic eccentricities was studied in [9].…”

Estimating forces in mixed eccentricities motion from purely dynamic eccentric rotor centre motion in a hydropower generator and their validation against EM simulations

“…R OTOR-stator eccentricity in electrical machines is an issue that has caught attention for a long time [1], [2] and is an important item in condition monitoring [3] in electrical machines. Though many papers in the literature [4]- [8] have addressed the issue of eccentricity in rotating electrical machines, and other papers [9]- [12] have dealt with mixed eccentricities (where both static and dynamic eccentricities occur) motion, there has been generally a lack of papers that account for the effect of whirling of the rotor. Two publications that have considered whirling are [13], [14].…”

No-load electromagnetic simulations of a hydropower generator considering the effect of rotor whirling

“…R OTOR-stator eccentricity in electrical machines is an issue that has caught attention for a long time [1], [2] and is an important item in condition monitoring [3] in electrical machines. Though many papers in the literature [4]- [8] have addressed the issue of eccentricity in rotating electrical machines, there has been a paucity of papers that account for the effect of whirling of the rotor. Examples of publications that have considered whirling include [9], [10].…”