3-phase Cage Research Articles

A study of the dependence of the 3-phase cage motor maximum torque on the centroid of the rotor bar section

A study of the dependence of the 3-phase cage motor maximum torque on the centroid of the rotor bar section

A study of the dependence of the 3-phase cage motor maximum torque on the centroid of the rotor bar section

The paper investigates the relative influence of the centroid of the three-phase squirrel cage induction motor rotor bar cross section, on the breakdown (maximum) torque of the machine. The influence of the angle of taper, the top width and the radial depth of the bar section, as established design variables, were also investigated so as to properly situate the degree of influence of the centroid, in comparison; as far as the maximum torque is concerned. The machines were investigated in their steady state operating mode using the equivalent circuit method. The machine learning capabilities of the Least Square Support Vector Machine (LSSVM) was deployed to extract by prediction, information about the likely dependencies between the randomized block of the geometric variables and the maximum torque, and the captured information was stored using the Root Mean Square Error (RMSE) of predictions. The validated results show that the rotor leakage reactance – a part determinant of the maximum torque; tends to show some significant sensitivity to a design change in the centroid of the transverse section of the rotor bar.

Analysis the Effect of Using Synchronous Motor as a Synchronous Condenser for Power Factor Improvement of 3-Phase Cage Rotor Induction Motor

Synchronous motors working at a capacitive power factor of 0.8 are obtained by providing a 0ver excitation, meaning operation at a capacitive power factor to improve the power factor of the system when connected to an inductive load, as is the case with an induction motor. A synchronous motor that is over-excitation will act like a capacitor and suck up the current that lead the voltage. A synchronous motor that works without a load that is given over excitation will function as a synchronous compensator whose capacitive value can be adjusted. The condition of this synchronous compensator is installed on a cage rotor induction motor as a power factor improvement. The results of this study showed that the power factor value of the induction motor before installing the synchronous compensator was cos φ = 0.88 and the reactive power was 132,84 VAR, after installing the synchronous compen sator, cos φ = 0.91 to 0.99 and the reactive power was 68 VAR to 28,2 VARs

A Steady-State Equivalent Circuit of TSCAOI Configured Induction Generator for Renewable Energy Conversion Systems

3-phase cage induction machines, operated in two series-connected and one-isolated (TSCAOI) winding configuration, have been proposed to generate standalone single-phase electricity at variable speeds for renewable energy conversion systems. However, the steady-state behaviour and performance of this particular generator are not yet to be theoretically investigated. This paper therefore presents the first theoretical investigation based on the steady-state equivalent circuit model for standalone TSCAOI configured generators. Moreover, this paper is the first to adopt the winding function approach to derive a dynamic mathematical model for TSCAOI configured generators. This approach not only eliminates the cumbersome mathematical manipulation required in all previous papers related to TSCAOI configured generators but also provides a visual insight into the resulting winding distribution of the machine. In order to investigate the load and excitation characteristics pertinently, the dynamic model is transformed into two different equivalent circuit models by appropriate selected transformation matrix. Using these two models, this paper identified the impacts of system parameters on the load and excitation characteristics, as well as on the level of voltage unbalance. Experimental results of a prototype generator under various operating conditions are presented, together with simulated results, to demonstrate the accuracy of the proposed investigations.

Oxidation Models of Rotor Bar and End Ring Segment to Simulate Induction Motor Faults in Progress

Oxidation models of a rotor bar and end ring segment in an induction motor are presented to simulate the behavior of an induction machine working with oxidized rotor parts which are modeled as rotor faults in progress. The leakage inductance and resistance of the rotor parts are different from normal values because of the oxidation process. The impedance variations modify the current density and magnetic flux which pass through the oxidized parts. Consequently, it causes the rotor asymmetry which induces abnormal harmonics in the stator current spectra of the faulty machine. The leakage inductances of the oxidation models are derived by the Ampere’s law. Using the proposed oxidation models, the rotor bar and end ring faults in progress can be modeled and simulated with the motor current signature analysis (MCSA). In addition, the oxidation process of the rotor bar and end ring segment can motivate the rotor asymmetry, which is induced by electromagnetic imbalances, and it is one of the major motor faults. Results of simulations and experiments are compared to each other to verify the accuracy of the proposed models. Experiments are achieved using 3.7 ㎾, 3-phase, and squirrel cage induction motors with a motor drive inverter.

Mixed fault analysis of 3-phase cage induction motor based on winding function theory

Mixed fault analysis of 3-phase cage induction motor based on winding function theory

Magnetic Flux Density Analysis of Cage Induction Motor Considering Magnetic Saturation by Permeance Model

This paper describes a method to analyze harmonic components of the air-gap flux density distribution on 3-phase cage induction motors, considering the influence of circumferential slot arrangement, stator winding pattern and distribution of air-gap permeance by magnetic saturation. The applied method is based on an analytical model of the permeance and the magnetomotive force distributions.The proposed method is applied to the analysis of a cage induction motor at no-load and full-load conditions. As a result, the harmonic components of the air-gap flux density distributions at different driving conditions are shown quantitatively. The proposed method is also confirmed by using the numerical analysis method (finite element method). From the comparison of these calculated results, the proposed method is shown to be appropriate and useful for quantitative estimation of harmonic flux for cage induction motors.

Study of Some Skew Effects for an Induction Motor by 3-D Analysis

In the paper, I study some effects of the rotor skew in a 3-phase cage induction motor using 3-D finite element analysis. At first, the calculation method of the equivalent circuit parameters by the results of the analysis is proposed and variations of the parameters by rotor skew are calculated. The harmonic secondary copper loss, which is a part of the stray losses, is calculated at each skew ratio. The calculation method of the iron loss is proposed and the effects of rotor skew about the harmonic iron loss are clarified. The reduction of the magnetic vibration force by rotor skew is understood quantitatively by the analysis. The following results are obtained.X1 and X2 which are T-type equivalent circuit parameters are increased and Xm is decreased by rotor skew. The harmonic secondary copper loss is reduced but harmonic iron loss is increased by rotor skew. The harmonic flux by the rotor slot pulsation are reduced by rotor skew in proportion to the skew coefficient but magnetic vibration force are not reduced in proportion to it, because the distribution of the flux density toward the axial direction is not uniformity by the axial direction flux made by the circular direction bar current, and many harmonic flux with different phase each other are overlapped at the air gap.

Temperature analysis of induction motors using a hybrid thermal model with distributed heat sources

The article presents a hybrid thermal model for the accurate estimation of temperature distribution of induction motors. The developed model is a combination of lumped and distributed thermal parameters which are obtained from motor dimensions and other constants such as material density, specific heats, thermal conductivity, etc. The model is especially suited for the derating of induction motors operating under distorted and unbalanced supply condition. The model have been applied to a small (2hp, 415 V, 3-phase) cage rotor induction motor. The performance of the model is confirmed by experimental temperature data from the body and the conductor inside the slots of the motor.

Stator slot shape design of induction motors for iron loss reduction

The shape design of stator slot of 3-phase cage induction motors for iron loss reduction is presented. For optimum shape design, the sensitivity analysis by discrete approach is employed and the gradient projection method for nonlinear constraint problems is chosen for an optimization algorithm. The 2D finite element method with voltage source is used to find the flux distribution in induction motors. >

Battery Operated Wheelchairs, Using 3-Phase Cage Rotor Induction Machines and PWM Inverters

Battery Operated Wheelchairs, Using 3-Phase Cage Rotor Induction Machines and PWM Inverters

Steady-state analysis of 3-phase cage motors with rotor-bar and end-ring faults

Steady-state analysis of 3-phase cage motors with rotor-bar and end-ring faults

Reply to the comments of Drs. Hargis and Vas on “Steady-state analysis of 3-phase cage motors with rotor-bar and end-ring faults”

Reply to the comments of Drs. Hargis and Vas on “Steady-state analysis of 3-phase cage motors with rotor-bar and end-ring faults”

Steady-state analysis of 3-phase cage motors with rotor-bar and end-ring faults

Steady-state analysis of 3-phase cage motors with rotor-bar and end-ring faults

Steady-state analysis of 3-phase cage motors with rotor-bar and end-ring faults

An analysis is developed for 3-phase induction motors with any distribution and number of rotorbar and end-ring failures. The method is verified, using an inverted-geometry cage motor on which careful measurements of rotor-bar currents are made. The analysis is then used to investigate a rotor-bar fault on a 250 hp, 8-pole, 60 Hz motor.

Determination of the parameters and parameter variations of a 3-phase induction motor having a current-displacement rotor

The paper describes a method of determining the parameters and parameter variations of a 3-phase cage induction motor having a current-displacement rotor. The method is based on the use of the Newton-Raphson procedure for the solution of two nonlinear equations in two unknowns, these being the rotor resistance and leakage reactance at any particular rotor frequency.