Modeling Eccentric Squirrel-Cage Induction Motors With Slotting Effect and Saturable Teeth Reluctances

Abstract

This paper mainly proposes a general model of eccentric squirrel-cage induction motor (SCIM), which includes the stator and rotor slotting effect as well as their individual tooth reluctance effect. Considering open slots on the stator and rotor, their rather exact shape is included in the machine's air gap function. Then, the resulting air gap function is used for evaluating various inductances of SCIM by the winding function approach (WFA). A simple general technique is used for adding eccentricity effect, including static, dynamic, and mixed eccentricities, on the air gap function and, therefore, on the inductances. Using a novel technique, saturable reluctance of each tooth of the stator and rotor is evaluated in every simulation step. Then, these reluctances are added to the model by equivalent increase of the air gap in front of the teeth; this reflects the teeth saturable reluctance effect on the inductances of the SCIM. In effect, dynamic simulation of SCIM with all aforementioned effects using WFA becomes possible. Simulation results compared to corresponding experimental results show accuracy and exactness of the proposed model.

Slot Numbering and Distributed Winding Effects Analysis on the Torque/Current Spectrum of Three-phase Wound-rotor Induction Machine Using Discrete Modeling Method

“…Regarding the obtained results, the frequency components in the magnetic torque and stator currents due to slot numbers can be written as Eqs. (22)- (25); it is notable that the obtained formulas are novel and have been obtained for first time in this article:…”

“…In [23], the closed-slot effect was studied on electrical machines harmonics, and stator current signatures were studied for cage rotor induction machines in [24]. In [25] the saturation effect was presented for teeth and slot and opening effect was considered, and in [26], which considered slot opening effects, a broken bar fault was researched for cage induction machines. In these works, there is none on the slot numbering effect on the current and torque spectral of wound-rotor induction machines.…”

Eccentricity fault diagnosis in three‐phase‐wound‐rotor induction machine using numerical discrete modeling method

“…According to Eqs. (13)(14)(15) combined with Eq. (7) self and mutual inductances can be computed by the turn functions while air gap function consists of three parts including rotor slots (gap r ), stator slots (gap s ) and conventional air gap (gap g ) as written in Eqs.…”

Cage-rotor induction motor inter-turn short circuit fault detection with and without saturation effect by MEC model

“…In [25][26][27] FEM and WFA were applied to study the wound-rotor induction and also synchronous reluctance machines and the PSD of torque and stator currents was used to analyze the machines performance in healthy and faulty conditions neglecting the saturation effect. In [28] the saturation effect of teeth and slot opening effect was considered simultaneously and in [29], broken bar fault has been studied for cage induction machines without slot opening effect. In [30], inductances of induction machines were computed in both healthy and faulty conditions excepting the saturation effect.…”