Rotor Induction Motor Research Articles

Comparative analysis of PID and neural network controllers for improving starting torque of wound rotor induction motor

Unlike 3-phase squirrel cage induction motor, starting-up of 3-phase wound rotor counter part can be improved by adding an external resistance to the rotor circuit.Thus, leads to reduce starting current and increase starting torque. In this paper two controllers for 3-phase wound rotor induction motor have been proposed include conventional proportional integral derivative (PID) controller and the other based on artificial neural network (NARMA-L2). A comparison between these controllers has been conducted. It has been shown that starting torque of the motor has been improved, when utilizing the neural network controller compared to the conventional counter part. It should be noted that MATLAB/SIMULINK has been used to implement both controllers.

Influence Analysis of Structural Parameters on the Performance of 120° Phase Belts Toroidal Winding Solid Rotor Induction Motor

120° phase belt toroidal winding solid rotor induction motor (120°PBTWSRIM) has advantages of simple structure, short end winding, and high overload capacity, thus it has good development prospects. To study the influence of different structural parameters on 120°PBTWSRIM performance, the 2D finite element model is established, and the electromagnetic characteristics are analyzed. The influence of six structure parameters on the average output torque, power factor, and torque ripple are analyzed, which are slot opening width, slot opening height, slot width, slot height, slot radius, and copper layer thickness. It is found that copper layer thickness has a significant effect on the performance of 120°PBTWSRIM. When the copper layer thickness is 0.5 mm, locked average output torque is increased to 2.784 Nm, locked power factor is increased by 64.6%, and locked torque ripple is reduced by 79.7%. Finally, a prototype of 120°PBTWSRIM is built and experimented, the correctness of performance influence analysis is verified by the comparison of results of the simulation and the experiment.

Sage Revised Reiterative Even Zernike Polynomials Neural Network Control with Modified Fish School Search Applied in SSCCRIM Impelled System

In light of fine learning ability in the existing uncertainties, a sage revised reiterative even Zernike polynomials neural network (SRREZPNN) control with modified fish school search (MFSS) method is proposed to control the six-phase squirrel cage copper rotor induction motor (SSCCRIM) impelled continuously variable transmission assembled system for obtaining the brilliant control performance. This control construction can carry out the SRREZPNN control with the cozy learning law, and the indemnified control with an assessed law. In accordance with the Lyapunov stability theorem, the cozy learning law in the revised reiterative even Zernike polynomials neural network (RREZPNN) control can be extracted, and the assessed law of the indemnified control can be elicited. Besides, the MFSS can find two optimal values to adjust two learning rates with raising convergence. In comparison, experimental results are compared to some control systems and are expressed to confirm that the proposed control system can realize fine control performance.

A Rectified Reiterative Sieved-Pollaczek Polynomials Neural Network Backstepping Control with Improved Fish School Search for Motor Drive System

As the six-phase squirrel cage copper rotor induction motor has some nonlinear characteristics, such as nonlinear friction, nonsymmetric torque, wind stray torque, external load torque, and time-varying uncertainties, better control performances cannot be achieved by utilizing general linear controllers. The snug backstepping control with sliding switching function for controlling the motion of a six-phase squirrel cage copper rotor induction motor drive system is proposed to reduce nonlinear uncertainty effects. However, the previously proposed control results in high chattering on nonlinear system effects and overtorque on matched uncertainties. So as to reduce the immense chattering situation, we then put forward the rectified reiterative sieved-Pollaczek polynomials neural network backstepping control with an improved fish school search method to estimate the external bundled torque uncertainties and to recoup the smallest reorganized error of the evaluated rule. In the light of Lyapunov stability, the online parametric training method of the rectified reiterative sieved-Pollaczek polynomials neural network can be derived by utilizing an adaptive rule. Moreover, to improve convergence and obtain beneficial learning manifestation, the improved fish school search algorithm is made use of to readjust two fickle learning rates of the weights in the rectified reiterative sieved-Pollaczek polynomials neural network. Lastly, the effectuality of the proposed control system is validated by examination results.

A Complete Equivalent Circuit for Linear Induction Motors With Laterally Asymmetric Secondary for Urban Railway Transit

Since the linear induction motor commonly work with a laterally asymmetric secondary as it is applied to pull rail vehicles, this paper presents a complete equivalent circuit model considering the asymmetry to predict thrust, vertical and transversal forces. First, six correction factors are presented to quantify the variations in the air-gap magnetic flux and secondary induced current as the linear induction motor operating with a laterally asymmetric secondary. Second, it develops a circuit model based on the existing T-model for the rotary induction motor and two correction factors for the magnetizing branch, which is used to indicate the electromagnetic variations in the air-gap flux and secondary plate due to the asymmetry. Third, the mathematical expressions for the thrust, vertical and transversal forces are derived by applying the equivalent circuit model. Then, the six correction factors are calculated with a prototype motor, and the results of them are comprehensively analyzed. Finally, the characteristics in the prototype motor are calculated with the mathematical expressions in a range of rated speed, and validated by the experimental measurements carried out on a test rig and line for linear motors.

Online Rotor and Stator Resistance Estimation Based on Artificial Neural Network Applied in Sensorless Induction Motor Drive

This paper presents a new approach method for online rotor and stator resistance estimation of induction motors using artificial neural networks for the sensorless drive. In this method, the rotor resistance is estimated by a feed-forward neural network with the learning rate as a function. The stator resistance is also estimated using the two-layered neural network with learning rate as a function. The speed of the induction motor is also estimated by the neural network. Therefore, the accurate estimation of the rotor and stator resistance improved the quality of the sensorless induction motor drive. The results of simulation and experiment show that the estimated speed tracks the real speed of the induction motor; simultaneously, the error between the estimated rotor and stator resistance using neural network and the normal rotor and stator resistance is very small.

Robust ANFIS Vector Control of Induction Motor Drive for High-Performance Speed Control Supplied by a Photovoltaic Generator

This paper presents the vector control of Induction Motor (IM) supplied by a photovoltaic generatorwhich is controlled by an adaptive Proportional-Integral (PI) speed controller. The proposed solution is used toovercome the induction motor rotor resistance variation problem, which can affect negatively the performanceof the speed control. To overcome the rotor resistance variation, an adaptive Proportional-Integral controller isdeveloped with gains adaptation based on Adaptive Neuro-Fuzzy Inference System (ANFIS) in order to guaranteea high performances of electric drive systems against the parametric variations. The proposed control algorithmis tested by Matlab-Simulink. Analysis of the obtained results shows the characteristic robustness to disturbancesof the load torque and to rotor resistance variation compared to the classical PI control and Model ReferenceAdaptive System (MRAS) rotor resistance observers.

Induction motor rotor bars type effects towards energy efficiency, economic and environment

<span lang="EN-MY">Nowadays, the rotating motor is the most demoralized machine for the global Motor industry. Comfort of practice, start-up, small, weightiness, Increased efficiency, low maintenance and inexpensive for each power rating that generally meets the necessary features for industries. Efficient improvements are inspected with copper for the rotor bars slot. Usually, the copper loss in the induction motor Rotor division contributes to the loss of energy. The research work was planned a new rotor design, by improved rotor bars type slot, size and design. These tasks were inspected using two approaches, in particular, MotorSolve (IM) and calculations in theory. One set of simulation has shown a significant increase in energy efficiency for a new rotor frame design. Calculations in theory are used MATLAB. As a result, these new designs have improved energy efficiency by 77% as compared to its 74% existing design. The results proved to be using MATLAB. For energy, cost savings and emission reduction (ER), new design rotor frame has been saved 154KWH/year, utility bill RM 60.20/Year and 0.113 CO<sub>2 </sub>tons/years intended for individually motor. Finally, the estimated cost aimed at 100,000 pieces of new rotor bars pattern induction motor and indicates this price was kept almost RM6 million.</span>

Reliable Flux-Based Detection of Induction Motor Rotor Faults From the Fifth Rotor Rotational Frequency Sideband

Motor current signature analysis (MCSA) is widespread in the field as a means of providing remote, online monitoring of industrial induction motor rotor faults. However, numerous cases of false indications with MCSA produced due to asymmetries in the rotor structure or load leading to unnecessary inspection or forced outages have been reported. Although alternative test methods under motor standstill or starting transient immune to the false indications have been proposed, a reliable method capable of “online” monitoring is desirable. In this article, a new fault indicator in the airgap or stray flux capable of reliable online detection is proposed. It is shown that the fifth sideband of the rotor rotational speed frequency can provide detection of rotor faults immune to most of the false MCSA indications. Experimental results under the most common false indications are provided to verify the claims made for cases where online MCSA produces false indications. The proposed fault indicator is also shown to be immune to eccentricity and common load defects such as load unbalance and misalignment.

RETRACTED ARTICLE: Mended grey wolf optimization and Taguchi method with multi-goal optimization for six-phase copper rotor induction motor design

We, the Editors and Publisher of the journal Engineering Optimization, have retracted the following article at the request and agreement of the author: Chih-Hong Lin (2020): Mended grey wolf optimization and Taguchi method with multi-goal optimization for six-phase copper rotor induction motor design, Engineering Optimization, DOI: 10.1080/0305215X.2020.1779251 The content of this article contains a high level of similarity with the published article below: Chih-Hong Lin (2020): Altered Grey Wolf Optimization and Taguchi Method with FEA for Six-Phase Copper Squirrel Cage Rotor Induction Motor Design, Energies, 13, 2282, DOI: 10.3390/en13092282 We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ‘Retracted’.

Static Eccentricity Fault Analysis in Inverter Fed Induction Motor using Finite Element Method

One of the common faults encountered in three phase induction motors (IM) is the eccentricity fault. In this work, a study on the electromagnetic characteristics of open-loop voltage source inverter fed IM is carried out for healthy and static eccentricity fault condition with the assistance of Finite Element Analysis. The importance of electromagnetic field analysis is it contains the data about the position of stator, rotor and mechanical parameters of IM. Thus the strategy of monitoring airgap magnetic fields and current are often used for the diagnosis of faults in IM. Detection of eccentricity fault at the incipient stage is difficult because the changes that the fault would introduce in the motor terminal quantities are negligible unless the severity is very high. A comparative study is carried out for healthy and eccentric fault motor with the help of ANSYS Maxwell Finite Element Analysis tool. Electromagnetic field parameters such as speed, current, flux distribution over the machine and in the air gap are analysed for healthy and faulty motor.

Field Analysis, Distribution and Performance of Sleeve Rotor Induction Motor Taking the Sleeve Rings into Consideration

In this paper, the field analysis of the sleeve-rotor induction motor taking the rings effect into consideration is carried out using the Maxwell’s field equations. A model in cylindrical coordinates is used to establish the rotor-rings and to solve the air gap magnetic field. The flux density is assumed to be constant through the very small air gap length while the skin effect through the axial rotor length is considered. The axial distribution of the air gap flux density, the sleeve current density components and the force density are obtained. The motor performance is carried out taking into account the effects of the sleeve rings performance characteristics. The effects of design data on the starting torque and the overload capacity of the motor are also considered.

Voltage unbalance evaluation in the intelligent recognition of induction motor rotor faults

Induction motors are widely used in several industrial applications due to their factors of favouritism already consolidated, such as robustness, low cost and high reliability. Early detection and proper fault diagnosis reduce the maintenance cost and also increase process effectiveness. Therefore, this paper presents a method for fast classification of rotor faults in line-connected induction motors operating at steady state, under unbalanced voltages and load conditions. Hence, the amplitude of the stator’s current signal in the time domain is presented as input to intelligent computational models for the classification of rotor’s faults. After a proper discretization of the current signal, the points extraction technique is applied allowing a reduction in the classifier’s complexity. Results from 900 experimental tests are provided and compared to validate this study. The results indicate that this approach can be employed to proper classify rotor broken bars in induction motors operating under unbalanced voltage and different load conditions.

Lyapunov Exponent and Spectral Analysis for Chaos Detection in the Wounded Rotor Induction Motor with an Internal Fault

ABSTRACT The conventional method for finding the location of turn-to-turn stator fault on the stator winding of the induction motor is spectral analysis. Using the harmonics method, the current spectrum can show the location of the fault. In this paper, it is shown that the chaos phenomenon could occur when fault arises on the motor. The spectrum of chaotic system has a wide range of harmonics. Consequently, spectral analysis is confused in this state. For this reason, first inductances of an induction machine with a turn-to-turn fault in stator winding are determined by the winding function theory. Using the nonlinear control theory, a first-order Poincare's map of the induction machine is computed and a new extended Poincare's map is drawn for the induction machines. In addition, the characteristic multipliers and the largest Poincare's exponents are calculated with this map. The new map is capable of modeling electrical machines in nonlinear and unbalanced cases for stability, bifurcation, and chaos analysis. The characteristic multiplier and Poincare's exponents of the extended map show the condition of a system. Chaos phenomena are observable in the condition of machines with a fault. In such cases, spectral analysis shows that the machine's current spectrum is varied in each period by a continuous spectrum of chaotic systems; consequently, identification of the location of an internal fault is not easily possible with conventional methods such as the Fourier spectrum or harmonics identification on a machine's terminal current. The experimental results supported the chaotic manner of the faulty induction motor.

Altered Grey Wolf Optimization and Taguchi Method with FEA for Six-Phase Copper Squirrel Cage Rotor Induction Motor Design

This paper presents an altered grey wolf optimization, the Taguchi method, and finite element analysis (FEA) with two-phase multi-objective optimization for the design of a six-phase copper squirrel cage rotor induction motor (SCSCRIM). The multi-objective optimization design with high-performance property aims to achieve lower starting current, lower losses, lower input power, higher efficiency, higher output torque, and higher power factor. The multi-objective optimization design with high-performance property using the altered grey wolf optimization, the Taguchi method, and FEA in the first-phase program is used for minimizing the starting current, stator iron loss, stator copper loss, and input power. The multi-objective optimization design with high-performance property using the altered grey wolf optimization, the Taguchi method, and FEA in the second-phase program is used for maximizing the efficiency, output torque, and power factor. Finally, the proposed skill with higher performances is evaluated and verified via a two-phase program design and some performance tests.

A study of metal/die interfacial heat transfer behavior of vacuum die cast pure copper

High pressure die casting copper is used to produce rotors for induction motors to improve efficiency. Experiments were carried out for a special “step-shape” casting with different step thicknesses. Based on the measured temperature inside the die, the interfacial heat transfer coefficient (IHTC) at the metal/die interface during vacuum die casting was evaluated by solving the inverse problem. The IHTC peak value was 4.5×103–11×103 W·m−2·K−1 under the basic operation condition. The influences of casting pressure, fast shot speed, pouring temperature and initial die surface temperature on the IHTC peak values were investigated. Results show that a greater casting pressure and faster shot speed could only increase the IHTC peak values at the location close to the ingate. An increase of pouring temperature and/or initial die surface temperature significantly increases the IHTC peak values.

A Method for Improving Power Factor in Inverter-Fed Induction Motors by the Use of Rotor Convex Copper Bars

Copper bars are often utilized in the rotor of a high power induction motor in order to reduce joule loss and improve overall efficiency. In this article, a kind of rotor convex copper bar is introduced instead of the conventional rectangle copper bar in the case of inverter-fed induction motors. The difference in the leakage reactance between the convex and the rectangle copper bar is analyzed. The use of convex copper bars can reduce the leakage reactance to some extent as the frequency rises. The decrease of the leakage reactance can contribute to restraining the ascending trend of the rotor reactive current. Finite-element method is taken to carry out the simulation, and a 550 kW prototype is produced to validate the proposed method. Experimental results indicate that the application of convex copper bars can help to lower the rotor reactive current and improve the power factor when the motor works near the end of the constant power area.

Design and performance analysis of novel multiphase induction motor with die-cast copper rotors using FEA for electric propulsion vehicles applications

PurposeThe purpose of this paper is to study the development of novel multiphase induction motor (MPIM) with copper die cast rotor in the drive system of electric propulsion vehicles (EPV). It is estimated that the manufacturers are concerned about high torque,Efficiency, motor life, energy conservation and high thermal tolerance. To ensure maximum torque and efficiency with multiphase winding and copper die cast technology to increasing high thermal tolerance, life, energy conversations. On other hand, it is very important of EPV application.Design/methodology/approachThe focus of the investigation is threefold: the modified method carried out on MPIM both stator and rotor can overcome the current scenario problem facing by electric vehicles manufacture and developed perfect suitable electric motor for EPV applications. The design and simulation carried out finite element method (FEM) that was more accurate calculations. Finally developed prototype model of MPIM with copper die cast are discussed with conventional three phase Die casting Induction motor.FindingsThe paper confirmed the multiphase copper die-cast rotor induction motor (MDCrIM) is providing better performance than conventional motor. Proposed motor can bring additional advantage like heat tolerances, long life and energy conversations.Originality/valueThe experiments confirmed the MDCIM suitable for EPV Applications. The modified MDCIM of both stator and rotor are giving better result and good performance compared to conventional method.

Research on eddy current losses algorithm in solid rotor of high speed squirrel cage induction motor

Aiming at the shortcomings of the analytical algorithm and numerical algorithm for calculating the eddy current losses in the solid rotor of high speed squirrel cage induction motor, this study proposes a semi-analytical algorithm. Based on the magnetic field of the rotor surface and Maxwell's equations, the analytical formula of this algorithm is derived. According to the law of energy conservation, the losses in rotor and rotor bars are calculated, respectively, so that the eddy current losses in the solid rotor are calculated indirectly. Taking a high speed squirrel cage induction motor as an example, the eddy current losses in the solid rotor are calculated by the semi-analytical method. The calculation result is verified by the two-dimensional transient finite-element method, and the calculation result meets the basic requirements of engineering practice.

Lateral and Torsional Vibration Monitoring of Multistack Rotor Induction Motors

In this article, both the lateral and torsional vibrations in multistack rotor induction motors (IM) are modeled in the same framework, and the corresponding precursors in the current waveform are analyzed in detail. Due to the very large rotor length-to-diameter ratio, rotor vibrations can become a major issue in these types of high-torque motors. In order to monitor the vibration components, the lumped mass-spring model for the rotors and couplings is developed to calculate the natural frequencies and torsional-mode shapes of the mechanical system. To model the electrical part, stator windings are split up into several identical windings that are connected in series and correspond to each rotor stack. Since the torsional vibration does not remarkably affect the winding symmetry, the dq model for each section is sufficient to describe the motor behavior during torsional oscillation. Similarly, for the lateral vibration, the mechanical system is modeled in all lateral directions and all modes. Due to the loss of symmetry, the abc model is used for each rotor and stator. In this modeling approach, all inductances (self and mutual of stator and rotor and the mutual inductances between the stator and rotor) are needed. To mimic the effect of lateral vibrations on the motor inductances, a new approach is developed using winding function theory. In this model, all inductances are formulated as a function of eccentricity severity and angle, and a new analytical IM model is developed to show the effects of lateral vibration. Finally, the experimental results are presented and compared with the analytical results.