squirrel cage
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This paper presents a proposed design and analysis of a three-phase squirrel cage induction motor when changing of internal characteristic design for the three-phase induction motor. Two situations have been applied to enhancing the performance of the three-phase induction motor. The first situation has been implemented by changing the magnetic flux density (MFD) via the build of the six-phase for the same induction motor. The second situation has been implemented by changing core materials of the rotor part of the induction motor, like aluminum (AL) and cast iron (CI). The finite element method (FEM) has been used to analyze the rotor part, also to obtain the representation and simulation of the realty cylindrical rotor part of motor. The frequency domain (FD) analysis using to obtain the results within the environment of the COMSOL multiphysics 5.5 version.

The performance evaluation of cage induction motor continues to receive tremendous attention because of its vital effect on the overall system stability. The model has predicted the behavior of cage induction motor under different operating conditions and in selecting the appropriate motor for a specific load application. There is often a challenge when a squirrel cage induction motor is connected to a time-varying load, particularly when the motor is selected without considering the effects of pulsating torques. The usual method used for steady state analysis of induction motors is the equivalent circuit method. Using the per phase equivalent circuit of the induction motor, stator current and referred rotor current were computed using simple circuit analysis. Once the currents are available, then power can be computed because the voltage is already known.

Purpose The aim of the paper is to investigate the impacts of simplifications of a reduced-order simulation model of squirrel cage induction machines (SCIMs) by numerical experiments. Design/methodology/approach Design of setups to isolate the main influences on the results of the reduced-order model of SCIMs. Results of time-stepping finite element calculations are used as benchmark. Findings Whereas neglecting eddy current effects and the assumption of a sinusoidal rotor current distribution leads to acceptable deviations in regular inverter operation, the sampling and interpolation of the machine parameters in a two-axis coordinate system considerably deteriorate the model accuracy. Using a polar coordinate system for this purpose is expected to significantly improve the model quality. Originality/value Preparing the ground for a successful, both fast and accurate simulation model of SCIMs as parts of electrified drivetrains.

The present paper addresses a precise and an accurate mathematical model for three-phase squirrel cage induction motors, based on winding function theory. Through an analytical development, a comparative way is presented to separate the signature between the existence of the outer race bearing fault and the static eccentricity concerning the asymmetry of the air gap between the stator and the rotor. This analytical model proposes an effective signature of outer race defect separately from other signatures of static eccentricity. Simulation and experimental results are presented to validate the proposed analytical model.

THE PURPOSE. The asynchronous electric motor with a squirrel cage rotor is widely used in the electric driven industry and agricultural machinery. One of the possible ways to improve its energy characteristics is to use a combined 12-zone stator winding instead of the standard 6-zone one. However, in a combined winding with a parallel connection of the «star» and «delta» phases, the phases may not be loaded equally. Therefore, the main purpose of the work under analysis is to study the distribution of currents between the phases of the «star» and «delta» in the asynchronous motor with a combined winding.METHODS. The study was performed on the AIR71V4 engine, rewound onto a combined winding, in which the real ratio of the active resistances of the «delta» and «star» turned out to be 7% less than the theoretical one. The tests were carried out in no-load and short-circuit mode when powered from a three-phase network, as well as in short-circuit mode when one of the line wires is broken.RESULTS. The work gives the values of the currents flowing through the phases of the combined winding. For the experimental sample, the deviation of the obtained currents from the theoretical values is determined. Equations of currents are obtained when one of the linear wires is broken. Schemes for switching on the main contacts of a thermal relay for a motor with a combined winding are proposed.CONCLUSION. The results of the study showed that in an asynchronous motor with a combined winding, in which the real ratio of the active resistances of the «delta» and «star» is less than the theoretical one, the current is not proportionally distributed over the phases. The most preferred circuit for switching on a thermal relay is one in which its main contacts are connected to the «delta» phases, and the thermal relay must be three-pole.

Abstract Agriculture is a socially significant sector of the economy. The growth of agricultural production contributes to the stable development of society. It is necessary to use new mechanisms driven by induction motors to increase agricultural productivity. Three-phase induction motors are mainly used in the electric drive of agricultural machines. At the same time, it is advisable to use a single-phase network to supply power to remote farms. In this regard, the development of a single-phase electric drive using three-phase motors becomes relevant. In this work, a study of an original semiconductor device for starting a three-phase induction motor from a single-phase network is made. The simulation model of the device created in the Matlab Simulink environment made it possible to study the electromechanical characteristics of the induction motor when operating from a single-phase network. A comparison of the characteristics of the motor during operation from a three-phase and a single-phase network is carried out. The most significant results of the work are the data obtained that the developed device can be used to start and operate a squirrel cage induction motor from a single-phase network. At the same time, the engine energy parameters change slightly.

Abstract: Wind energy is one of the most important and promising sources of renewable energy all over the world. Throughout the globe, in the last, three- or four-decades generation of electricity from wind energy has created a wide interest. At the same time, there has been a rapid development of wind energy-related technology. The control and estimation of wind energy conversion systems constitute a vast subject and are more complex than those of dc drives. Induction generators are widely preferable in wind farms because of their brushless construction, robustness, low maintenance requirements, and self-protection against short circuits. Low cost, robustness, and ease of maintenance are attractive features of induction generators. With wind turbine and micro/mini-hydro generators as an alternative energy source, the induction generators are being considered as an alternative choice to well-developed synchronous generators because of their simplicity, ruggedness, little maintenance, price, brushless (in squirrel cage construction), absence of separate dc source, self-protection against severe overloads and short circuits. In isolated systems, squirrel cage induction generators with capacitor excitation, known as self-excited induction generators (SEIGs), are very popular. This paper presents a review of literature related to the present status of research work on self-excited induction generators (SEIG), their terminal voltage control strategies, and over the past years discussing the classification of induction generators, steady-state and transient analysis, voltage control aspects, and parallel operation of SEIG.

This paper presents a developed method to calculate the parameters for thirty-three squirrel cage induction motors operating at three-phase ac voltage of 380 volts. These motors are the total product of an Egyptian factory holding a license from SIEMENS international company to fabricate all parts of these motors. The parameters of all mentioned motors are computed based on the proposed method. Then, the performance characteristics of these motors are investigated at full-load using the conventional equivalent circuit in order to validate the proposed method. The obtained curves achieve significant convergence with the full-load values provided by the data sheets of investigated motors. This confirms the validity of the proposed method.

Abstract The paper is devoted to current issues of locomotive asynchronous traction motor (ATEM) fault detection using neural networks. Developed sophisticated intelligent methods for monitoring and inspecting the technical condition of ATE bearings. Current absorption spectra are analysed to assess the technical condition of the induction bearing units. The mechanical vibration frequencies of a squirrel cage induction motor are presented. The method of artificial neural networks which are universal approximators and can effectively and efficiently solve problems of monitoring and diagnostics of technical condition of locomotive induction traction motors is applied. A neural network model and framework for monitoring the technical condition of ATED bearings has been developed. They are based on rules and user-provided facts to recognise the situation, make a diagnosis, formulate a solution or make a recommendation. The main failures of the bearing units of squirrel cage ATED are analysed. A methodology has been developed to build a neural network model of the ATED. The structure and architecture of the artificial neural network is defined. An experimental research has been conducted. The results enable the determination of bearing faults in asynchronous traction motors with squirrel cage rotor.