Three-phase Squirrel-cage Induction Motor Research Articles

Simulation of Selected Induction Motor Operating Conditions Using COMSOL Software

In this paper, some results from a simulation of three-phase squirrel-cage induction motor using COMSOL Multiphysics software are shown for the selected motor operating conditions. The simulation has been carried out under the nominal operating condition at the nominal rotational speed, for the operation under no-load and for the operation under locked rotor. The waveforms of the stator current, the currents in two neighbouring rotor bars, the current in the rotor ring and the motor inner torque are presented for each tested condition. The simulated values of some motor parameters are compared to their values from the motor catalogue, the manufacturer’s measurement, or the measurement in our laboratory, respectively. The simulated values of the rotor bar current and the rotor ring current are compared to their values from the scientific literature. The parameters of the motor equivalent circuit are calculated by COMSOL and compared to the values calculated from the motor data plate and from the measured values.

Modeling, Simulation and Analysis of Induction Motor for Electric Vehicle Application

High power induction motor (IM) is widely used in industries and recently has been put into electric vehicle as the replacement of the internal combustion engine. In order to study the characteristics of the IM, a model of three-phase squirrel cage induction motor is designed and developed using MATLAB Simulink tool. Synchronous reference frame (SRF) technique is implemented to simplify the equivalent circuit model. Based on state space form, a flux linkage equation is developed using three stages transformation matrices. It demonstrated a good performance with fast response for AC start-up test, where simulated induced torque, rotor speed, mechanical output power, efficiency, slip and stator current waveforms were generated accordingly. Indeed, the developed IM model can be used as a starting platform to further study and analyses the IM drives performance for electric vehicle application.

Higher-Order Statistics applied to machine learning as an approach to identify broken rotor bars in induction motors

Induction motors are reported as the horse power in industries. Due to its importance, researchers have been studied how to predict its faults in order to improve reliability. Condition health monitoring plays an important role in this field, since it is possible to predict failures by analyzing its operational data. This paper proposes the usage of vibration signals, combined with Higher-Order Statistics (HOS) and machine learning methods to detect broken bars in a squirrel-cage three-phase induction motor. The Multi-Layer Perceptron and Optimum-Path Forest have presented as promising approaches for faults classifications in an induction motor.

Unified Modeling Technique for Axially Uniform and Nonuniform Eccentricity Faults in Three-Phase Squirrel Cage Induction Motors

Many mechanical faults cause eccentricity in squirrel cage induction motors (SCIMs), so it is reasonable to design and implement reliable eccentricity fault diagnosis systems for the SCIMs. Accurate modeling and simulation techniques help to reach this aim more easily. It is common to assume that the eccentricity fault is uniform along the motor length when modeling and simulation that is often far from real situation. In this paper, experimental inspection is performed first to show that having the same severity of eccentricity at one end of the motor, the axially nonuniform eccentricity may produce lower fault indices than the axially uniform eccentricity. Then, the two-dimensional (2-D) modified winding function theory is presented and used to obtain analytic expressions for various self-/mutual inductances of the stator windings and the rotor meshes and their derivatives versus the rotor position. The expressions are applicable under various axially uniform and nonuniform eccentricities as well as the healthy condition. Multiple coupled circuit model is used along with these expressions to develop a comprehensive analytic model for the SCIMs. Simulation results obtained by this model are in good agreement with corresponding experimental results and confirm accuracy of the attained modeling and simulation technique.

Analytic Model for Induction Motors Under Localized Bearing Faults

The bearing faults are the major root cause for the induction motor failures; however, almost all the related fault diagnosis methods have been based on the laboratory tests, which are costly and inflexible. Localized defects in various components of roller bearings cause radial vibration of the rotor, little variation of the load torque, and various harmonics in the stator current. Ignoring the load torque variation, this paper applies the multiple coupled circuit modeling to simulate three-phase squirrel-cage induction motors under the localized bearing faults by introducing appropriate air gap function. Fast Fourier transform is used for exact analysis of the harmonic content of the inverse of the air gap function. The analysis is completed by including the saturation effect and the inherent eccentricity of the motor. Then, a broad list of harmonics presentable in the stator current spectrum under the bearing faults is determined. The list may include the characteristic vibration frequencies related to the bearing components faults. Also, it is clear that the inner raceway fault can produce the same harmonics in the stator current as produced by the mixed eccentricity. Experimental results approve the simulation results and the mentioned facts.

Low‐cost SPLL‐based electrical faults identification for three‐phase squirrel cage induction motor using handheld Doppler radar signal analysis

The condition monitoring of an induction motor performs by contact or non-contact methods. The contact methods execute via vibration signal, temperature measurement, current signature analysis and so on, and the non-contact methods accomplish via thermal imaging, temperature measurement and acoustic emission measurement. The contact method requires human expertise to evaluate failures and it is laborious. The authors propose a novel, low-cost and non-contact method using software phase locked loop (SPLL) for electrical fault identification in the three-phase squirrel cage induction motor. The handheld Doppler ultra wideband radar transmitted signal is focused on the induction motor and the reflected signal is analysed with SPLL. The SPLL error signal correlates the faults. From the experimental results, the fault identification of motor in the earlier stage achieves better accuracy of the different motor fault condition. The pattern of error signal provides the information of various faults in squirrel cage induction motor.

Power Factor Correction of Four-Switch Three-Phase Inverter-Fed Sensorless Induction Motor Drives with Partial Electrical Free Measurement

In this article, a novel partial electrical free measurement method to improve the power-factor of four-switch three-phase (B4) inverter for sensorless induction motor drives is proposed. This method uses a simple-free of measuring current or voltage for the power factor correction circuit. The proposed controller of the B4 inverter improves the power factor to be closed to a unity with a high power quality performance and with a minimum total harmonic distortion of the supply current. The complete drive system is carried out utilizing Matlab/Simulink. Also, it is executed in real-time using a prototype system composed of a dSPACE DS-1104 digital control board and a laboratory 1.1 kW three-phase squirrel cage induction motor. The simulation and experimental waveforms prove the efficacy of the proposed drive system under various operating conditions. It is found that the proposed drive system has a reduced number of switches and sensors with a minimum cost which suitable for low commercial power applications. Moreover, it enhances noise isolation between power circuit and controller.

Performance indexes’ evaluation of a NSynRM with sinusoidal rotor shape

This study presents the evaluation of performance indexes of a novel synchronous reluctance motor (NSynRM) that has an axially sinusoidal rotor lamination shape. The stator of a 5.5 kW, 4-pole, 50 Hz conventional three-phase squirrel cage induction motor, with distributed and chorded by one slot, double-layer winding, is used for both standard and NSynRMs. Owing to the nature of the sinusoidal rotor structure, the three-dimensional finite element analysis (FEA) is utilised to study the electromagnetic parameters of interests. The NSynRM with sinusoidal rotor shape results is compared with the standard SynRM without cut-off on the q -axis. The FEA results are validated by means of practical measurements.

Designand application of data aquistion interface circuit

A commitment to condition monitoring involves the operators of plant in the conduct of a range of activities. These activities may be complicated in nature and indeed may often be performed automatically under computer control. They can, however, always be down into a relatively small number of easily identifiable functional tasks. This makes it much easier to identify the common elements of machine condition monitoring schemes. A proposed interface circuit design and application will be further explain in this paper, the implemented monitoring unit circuit also illustrated, see appendix A. Two scenarios presented in this paper, first ten turns assume to be shorted, and in the second thirty turns shorted to show the difference in the amplitude of frequencies at each case. This paper present. An improvement in three-phase squirrel-cage induction motor stator inter-turn fault detection and diagnosis based on a neural network approach is presented.

Real-Time SOSM Super-Twisting Combined With Block Control for Regulating Induction Motor Velocity

On this paper, a robust velocity controller applied to a three-phase squirrel-cage induction motor under variable load conditions is designed. The induction motor drives an induction generator representing the load which freely delivers the generated power to the utility grid. The closed-loop scheme is designed at $\alpha \beta $ coordinate frame and is based on the linearization block control technique in combination with the super-twisting algorithm. The controlled output variables are the angular mechanical velocity and the square modulus of rotor flux linkages. The motor reference velocity is set up by a pulse train above the synchronous velocity and, consequently, the impelled induction machine operates in generator mode; meanwhile, the reference of rotor flux square modulus varies according to load condition of the induction motor. In order to estimate the non-measurable variables, both a rotor flux linkages observer and a load torque observer are designed. For the first one, a non-linear state observer using first order sliding modes is applied at $\alpha \beta $ coordinate frame and, for the second one, a Luenberger reduced asymptotic observer is used. The validation of the robustness for the proposed velocity controller is performed in a real-time experiment using a work-bench.

Efficiency Evaluation of Three Phase and Single Phase C2C Self-Excited Induction Generator for Micro Hydro Power Application

Squirrel-cage induction motor (SCIM) is used as generator to a great extent for micro hydropower applications due to their robustness, brushless construction, low cost, reliability, rare maintenance, and availability in a wide power range. Squirrel-cage induction generator (SCIG) normally requires excitation capacitors to build up the terminal voltage from residual magnetism. However, for rated and stable voltage and frequency operation, selection of an appropriate size of excitation capacitor is crucial. This paper presents the efficiency evaluation of an SCIG with different excitation capacitors to supply three-phase and single-phase resistive loads. A 1.5-kW three-phase SCIM was selected as the SCIG driven by a 3-kW three-phase SCIM as a prime mover. The shaft speed was controlled by a variable speed drive (Yaskawa A1000) with an incremental encoder for the speed feedback. Shaft torque was obtained from a torque sensor (TRB-2K) installed in between the two machines. Parameters of the SCIG were determined by DC, no-load, and locked rotor tests, then the required excitation capacitance was calculated. For three-phase operation star connected SCIG was excited by the capacitors in star connection to supply a three-phase resistive load. For the single-phase operation, the delta connected SCIG was excited with so-called C2C configuration.

Current signature based fault diagnosis of field-oriented and direct torque–controlled induction motor drives

In this article, the operation of three-phase squirrel-cage induction motors is analysed under faulty conditions in closed loop with state-of-the-art controllers, namely, the field-oriented control...

Modelling of squirrel cage induction motors for a bio‐inspired multi‐objective optimal design

The design of efficient three-phase induction motors is a challenge for engineering; therefore, new design techniques are continually being proposed. For example, efficiency is in conflict with manufacturing cost, which leads to the use of multi-objective optimisation techniques to solve this engineering problem. Nevertheless, this study shows that the way of accurately modelling the behaviour of the motor is as important as the optimisation method itself. Thus, the study discusses fundamental considerations in the motor model as part of a proposed methodology for the design of highly efficient three-phase squirrel cage induction motors. For this purpose, the motor is modelled in two ways: an analytical equivalent circuit and the finite element method, which are validated with data obtained from laboratory tests. The main contribution of this study is to show for the first time the required characteristics of the analytical model used as part of a multi-objective optimisation problem to have a suitable accuracy with a competitive runtime. Moreover, the problem is solved using three bio-inspired optimisation algorithms: non-dominated sorting genetic algorithms II, non-dominated sorting particle swarm optimisation and bacterial chemotaxis multi-objective optimisation algorithm. The methodology is tested in the optimal redesign of a two-pole, 3.7 kW, IE2 efficiency motor, for which the efficiency and cost were improved.

Diagnosis and classification using ANFIS approach of stator and rotor faults in induction machine

Three-phase squirrel cage induction motors are one of the important elements of the industrial production system, and are mostly used because of their robustness, reliability, relatively simple construction and their low cost. Nevertheless, during their function in different process, this machine types are submitted to external and internal stresses which can lead to several electrical or mechanical failures. In this paper, we proposed a reliable approach for diagnosis and detection of stator short-circuit windings and rotor broken bars faults in induction motor under varying load condition based on relative energy for each level of stator current signal using wavelet packet decomposition which will be useful as data input of adaptive neuro-fuzzy inference system (ANFIS). The adaptive neuro-fuzzy inference system is able to identify the induction motor and it is proven to be capable of detecting broken bars and stator short-circuit fault e with high precision. The diagnostic ANFIS algorithm is applicable to a variety of industrial process based on the induction machine for detection and classified the any faults types. This approach is applied under the MATLAB software®.

Optimum MPPT Technique for the PV based Field Oriented Control of Induction Motor Feeding Centrifugal Pump

Objectives: To develop and analyze isolated photovoltaic based water pumping system employing Field Oriented Controlled (FOC) three-phase squirrel cage Induction Motor (IM) which in turn is used to run the centrifugal pump. To extract the maximum power from the solar panel during all conditions, Maximum Power Point Tracker (MPPT) has to be implemented. Method/Analysis: FOC-IM of 5th order differential equations have been solved using Runga Kutta Method for integration with dq axis in rotor reference frame in MATLAB/Simulink environment. The two MPPT techniques are based on calculations of the instantaneous values of the voltage and current of the PV cell. The Perturb and Observe (P&O) technique is based on the value of perturbation and the Incremental Conductance (INC) technique is implemented using the value of the Incremental Conductance. Findings: The power generation from various renewable energy sources is becoming popular because of greater efficiency and depletion of non renewable energy sources. In this paper, an isolated photovoltaic based model is considered which can be suitable for the remote areas where there is no grid connectivity. From the exhaustive study of literature, it is found that very few authors have worked on induction motor and that too employing FOC for PV based model. The characteristics of the Induction Motor are such that it draws high inrush current at starting. The peak power ratings of the inverters and converters depend on this starting current in such finite PV based sources. This ultimately leads to the high cost of the whole system. The analysis to this problem has not been discussed yet, which is an important concern in the field of PV based electric motor drives. This work is incorporated to achieve this objective. Novelty/Improvement: The whole developed model is analyzed using the two MPPT techniques viz Incremental Conductance and Perturb and Observe MPPT. The problem of starting current in the motor and the distortions in the torque deviations are highly dependent on the choice of MPPT. So keeping in view of the above two problems, the optimum MPPT technique has been stated in this work.

An Approach to Improve the Performance of Three-phase Self-excited Induction Generator Feeding an Induction Motor Load using Hilbert Transform and Coordinate Rotation Digital Computer

Self-excited induction generators are mostly preferred in isolated areas to feed three-phase squirrel-cage induction motors for agricultural purposes to pump water. When the induction motor is connected to the self-excited induction generator without any voltage and frequency controller, it causes severe transients in the electrical and mechanical variables of the generator. Due to the large starting current requirement of the induction motor, there is a collapse of the terminal voltage of the generator; thus, the self-excited induction generator requires a voltage and frequency controller to run an induction motor safely in remote and isolated areas. This article presents a voltage and frequency control scheme for the self-excited induction generator to run an induction motor using a generalized impedance controller. The novelty of this work is to estimate the peak terminal voltage and frequency of the self-excited induction generator using Hilbert transform and the Coordinate Rotation Digital Computeralgorithm. The proposed scheme requires only one voltage sensor, and its output voltage is processed to estimate peak voltage and control the modulation index of the generalized impedance controller to control the self-excited induction generator voltage and frequency and run the induction motor without causing any disturbance.

Static air-gap eccentricity fault diagnosis using rotor slot harmonics in line neutral voltage of three-phase squirrel cage induction motor

The mixed eccentricity fault detection in a squirrel cage induction motor has been thoroughly investigated. However, a few papers have been related to pure static eccentricity fault and the authors focused on the RSH harmonics presented in stator current. The main objective of this paper is to present an alternative method based on the analysis of line neutral voltage taking place between the supply and the stator neutrals in order to detect air-gap static eccentricity, and to highlight the classification of all RSH harmonics in line neutral voltage. The model of squirrel cage induction machine relies on the rotor geometry and winding layout. Such developed model is used to analyze the impact of the pure static air-gap eccentricity by predicting the related frequencies in the line neutral voltage spectrum. The results show that the line neutral voltage spectrum are more sensitive to the air-gap static eccentricity fault compared to stator current one. The theoretical analysis and simulated results are confirmed by experiments.

Proposed fault diagnostics of a broken rotor bar induction motor fed from PWM inverter

This paper presents a fault diagnostics technique for a three-phase squirrel cage induction motor. The method is developed using a simplified model affected by bar resistance variation. Based on 3-phase time domain model, the rotor broken bar with different conditions has been simulated to investigate the resulting torque speed characteristic in each condition. The developed fault diagnostics system is capable of identifying the type of the broken-bar faults in the squirrel cage induction machines.

Optimization of Three-phase Squirrel Cage Induction Motor Drive System Using Minimum Input Power Technique

The efficiency of induction motor drives operating under variable conditions can be improved by predicting the optimum flux that minimizes the losses. In this study, a Loss-Minimization Controller (LMC) and a Search Controller (SC) are combined. The output from the controllers would drive the field oriented control inverter in order to achieve the optimum flux in the motor that minimizes the losses. For this purpose, a mathematical model for calculating the total power losses as a function of magnetic flux and a factor to obtain feedback as a function of optimum flux were discussed. An LMC-SC vector-controlled induction motor drive system was modelled, simulated and tested. The results have validated the effectiveness of this system in minimizing the motor operating losses, especially at light and medium loads. The proposed controller can be implemented in adjustable speed induction motor drive systems with variable loads, operating below rated speed.

Analysis of Induction Motor with Broken Bars and Constant Speed Using Circuit-Field Coupled Method

The paper presents the use of the two-dimensional finite element method for modeling the three-phase squirrel-cage induction motor by using circuit coupled method. In order to analyze the machine performances, the voltage source is considered. The Ansys magnetic analysis software is used for calculating the magnetic field of an induction motor having a cage fault. The experimental results prove that the proposed approach constitutes a useful tool for the study and diagnostics of induction motors.