Analysis Of Squirrel Cage Induction Motor Research Articles

Impedance analysis of squirrel-cage induction motor at high harmonics condition

This study examines different methodologies for representing an asynchronous motor at higher harmonics by utilizing its equivalent circuit. Several approaches were compared based on simulation modeling. An experimental investigation was conducted in a laboratory setting using asynchronous electric motors with power ratings of 1.5 kW and 5.5 kW. The purpose of this investigation was to examine the characteristics of impedance in the presence of high-harmonic conditions. The generation of higher harmonics was achieved through the utilization of a precisely regulated thyristor rectifier in conjunction with a thyristor power controller. The findings indicate that the load on the shaft solely impacts the resistance at the fundamental harmonic, while the resistance at higher harmonics remains unaffected by the operating mode of the asynchronous motor (AM).

Performance Analysis of Squirrel-Cage Induction Motors Under Broken Rotor Bar and Stator Inter-Turn Fault Conditions Using Analytical Modeling

Stator winding inter-turn (SWI) short-circuit fault and broken rotor bar (BRB) fault are two common faulty modes of the squirrel cage induction motors (SCIMs). These faults have various impacts on the motor performance and may be rooted in each other; therefore, they may be presented at the same time in an SCIM. This paper proposes an exact analytical model for the SCIMs, which is able to include the SWI and BRB faults presenting simultaneously or individually with variable severities. Multiple coupled circuit modeling is applied to achieve such analytical model. The magnetic saturation effect is included in the model by applying appropriate air gap function and the rotor bars skew effect is taken into account by using 2-D winding function theory. Simulation results as well as the corresponding experimental results approve the presence of the same harmonics in the stator line currents due to the proposed faults. However, more detailed study gives solution for discrimination of the faults. The attained analytical model can be applied to examine the performance of the related fault diagnosis methods and to design novel fault diagnosis techniques including the model-based ones.

Comparison of Two Anisotropic Layer Models Applied to Induction Motors

A general description of the Anisotropic Layer Theory, which is derived in the polar coordinate system and applied to the analysis of squirrel-cage induction motors (IMs), is presented. The theory considers nonconductive layers, layers with predefined current density, and layers with induced current density. The electromagnetic field equations are solved by means of Fourier analysis. Furthermore, two different magnetic models for IMs are proposed, namely, the direct rotor current model and the indirect rotor current (IRC) model. The magnetic models are coupled to the single-phase equivalent circuit by means of an iterative algorithm, which also accounts for saturation of the main flux path. Finally, the calculation results are validated against results obtained from measurements on two benchmark motors. Comparison of the validation results shows that the IRC model is the more promising one.

Closed-Form Analysis of Squirrel-Cage Induction Motors With Anisotropic Modeling of Stator and Rotor

This paper presents a closed-form solution of Maxwell's equations in squirrel-cage induction motors. The solution is obtained for a cylindrical multilayer geometry. The squirrel cage is represented by an equivalent anisotropic homogeneous medium. The effect of stator slots and teeth is included by a second anisotropic homogeneous medium. The induction motor is modeled as six concentric cylindrical layers representing the different construction components of the motor. The governing partial differential equations are solved for the excitation source, conducting, and nonconducting regions. The obtained formulas allow for efficient calculations of machine performance which may help the motor designer to select the proper parameters of the machine that fit the design requirements. Accuracy of the method is verified against finite element simulations, a commercial motor design program, and experimental results.