Use Of Induction Motors Research Articles

English

This paper proposes a design of a speed control of three phase induction motor fed from wind turbine using genetic algorithm. The wind turbine acts as a prime-mover for doubly fed induction generator. To make the system stable, proper monitoring is required or sometimes an auxiliary system can also be a good option, which can support the primary system during undesirable conditions. The three phase induction motor has wide applications in industries due to its rugged construction, efficiency and low cost. Genetic algorithm is used for estimation of feedback controller parameters for three phase induction motor fed from wind turbine .Genetic algorithm offers certain advantages such as simple computational steps, derivative free optimization, reduced no. of iteration and assured near global optima. The simulation results show a significant enhancement in shortening development time and improving dynamic performance of the induction machine compared to the conventional speed control of induction motor drive. I.INTRODUCTION This study proposes the genetic algorithm for optimal designing of fuzzy controller for speed control of Induction motor fed by wind turbine, which has a simple structure and robust performance in a wide range of operating conditions. The use of induction motors has increased tremendously since the day of its invention. The reason for its day by day increasing popularity can be primarily attributed to its robust construction, simplicity in design and cost effectiveness. These have also proved to be more reliable than DC motors. However, the highly non-linear nature of the induction motor control dynamics demands strenuous control algorithms for the control of speed. The conventional controller types that are used for the aforementioned purpose may be numeric, neural or fuzzy. The controller types that are regularly used are: Proportional Integral (PI), Proportional Derivative (PD), Proportional Integral Derivative (PID), Fuzzy Logic Controller (FLC) or a blend between them. Intelligent control methodologies are being applied to robotics and automation, communications, manufacturing, traffic control, to mention but a few application areas. The design problem of the proposed controller is formulated as an optimization problem and genetic algorithm is employed to search for optimal controller parameters. By minimizing the time domain objective function, in which the deviations in error between the reference and actual speed is involved, speed control of Induction motor is improved.

LPC 분석 기법 및 EM 알고리즘 기반 잡음 환경에 강인한 진동 특징을 이용한 고 신뢰성 유도 전동기 다중 결함 분류

최근 산업 현장에서 유도 전동기의 사용이 증대되고 있으며, 유도 전동기는 산업 현장에서 중요한 역할을 하고 있다. 따라서 유도 전동기의 결함으로 인한 피해를 최소화하기 위해 유도 전동기의 결함 검출 및 분류 시스템의 개발이 중요한 문제로 대두되고 있다. 따라서 본 논문에서는 유도전동기의 결함을 조기에 식별하기 위해 선형예측 코딩(LPC)기법과 Expectation Maximization(EM) 알고리즘을 이용하여 각각의 유도 전동기 고장의 스펙트럼 포락처리 모델을 추정한다. 앞서 두 기법을 사용하여 추정된 고장 유형 모델과 마할라노비스 거리(MD) 기법을 사용하여 유도전동기의 결합을 분류한다. 또한 제안된 알고리즘 성능을 평가하기 위해 기존에 제안된 진동 신호의 특징을 이용한 유도 전동기 결함 분류 알고리즘과 분류 정확도 측면에서 성능을 검증하였다. 실험 결과, 제안하는 알고리즘은 잡음이 없는 환경 및 잡음이 섞인 환경에서도 높은 분류 성능을 보였다. The use of induction motors has been recently increasing in a variety of industrial sites, and they play a significant role. This has motivated that many researchers have studied on developing fault detection and classification systems of induction motors in order to reduce economical damage caused by their faults. To early identify induction motor faults, this paper effectively estimates spectral envelopes of each induction motor fault by utilizing a linear prediction coding (LPC) analysis technique and an expectation maximization (EM) algorithm. Moreover, this paper classifies induction motor faults into their corresponding categories by calculating Mahalanobis distance using the estimated spectral envelopes and finding the minimum distance. Experimental results show that the proposed approach yields higher classification accuracies than the state-of-the-art conventional approach for both noiseless and noisy environments for identifying the induction motor faults.

The Re-examination of Adjustment of the Rotor Magnetic Field Observer in the Induction Motor

Abstract Wide use of induction motor drives makes the problems related to induction motors very topical. One of such problems is the maximal utilization of torque and velocity of induction motors. In this regard the use and accurate adjustment of rotor magnetic flux observers may be helpful. The technique of observer adjustment is subject of special interest. This technique can be regarded as optimal if it ensures constant acceleration that, in turn, corresponds to constant magnitude of active and magnetizing components of stator current. In contrast, nonoptimal tuning of the magnetic flux observer creates a transient response caused by variation of magnetic and active components of the stator current resulting in changing acceleration of the motor. However, the parameters of non-optimal process can be used for fine tuning of the observer which considers the variation of the time constants obtained analyzing the drive's magnetic circuit saturation. It is possible to conclude that implementation of fine adjustment of rotor magnetic flux observer is of critical importance for induction motor torque and velocity maximum utilization.

Fault-tolerant cruise control of electric vehicles with induction motors

A fault-tolerant control scheme is proposed for the cruise control of electric vehicles (trains, cars) that make use of induction motors. It relies on a rotor speed reference generator and on a flux observer which is adaptive with respect to the uncertain rotor and stator resistances and to the load torque as well. The closed loop on-line identification of those three critical uncertain parameters allows for: (i) on-line estimating and imposing the motor flux modulus reference value which minimizes power losses at steady-state and improves power efficiency; (ii) the on-line detection of speed sensor faults as well as the fast switching on redundant motor speed sensors. CarSim simulations illustrate the effectiveness of the proposed approach.

Direct Comparison of Induction Motor and Line-Start IPM Synchronous Motor Characteristics for Semi-Hermetic Compressor Drives

Motors in semi-hermetic compressor drives are mostly fed from line. Because of good cooling conditions, the motors are heavily loaded and employ a specific rotor structure with “C” bore. In the field of semi-hermetic drives, the use of induction motors (IMs) is still dominant, although different motor types with line-starting capabilities, as for example line-start interior permanent magnet synchronous motors (LSIPMSMs), can be used. This work presents the direct performance comparison of a family of commercially available three-phase four-pole IMs for semi-hermetic compressor drives with the equal size prototypes of LSIPMSMs. The motors were rated as 1, 2.5, 3.8, 5.5, 7.5, and 20 hp. The presence of “C” bore in rotor structure can degrade LSIPMSM steady-state performance; therefore, the LSIPMSM designs steady-state performances are evaluated by FEA as well by the experimental method. The motors' dynamic performance is experimentally evaluated as well. The ultimate goal of this study is to reveal the improvement of LSIPMSMs characteristics in comparison to IMs characteristics and to check the possibility for the immediate replacement of existent IMs with LSIPMSMs in the target semi-hermetic compressor application.

유도 전동기의 고장 검출 및 분류를 위한 특징 벡터 추출과 분류기의 다양한 설정에 따른 분류 성능 비교

최근 항공 산업, 자동차 산업 등의 산업 현장에서 유도 전동기의 사용이 증대되고 있으며, 유도 전동기는 산업 현장에서 중요한 역할을 하고 있다. 따라서 유도 전동기의 고장으로 인한 피해를 최소화하기 위해 유도 전동기의 고장 검출 및 분류 시스템의 개발이 중요한 문제로 대두되고 있다. 이와 같은 이유로 본 논문에서는 유도 전동기의 고장을 조기에 검출하고 진단하기 위해 에너지 (short-time energy)와 특이치 분해와 이산 코사인 변환과 특이치 분해를 이용한 특징 벡터 추출 방법을 제안하였고, 이를 역 전파 신경 회로망과 다층 서포트 벡터 머신의 입력으로 이용하여 유도 전동기의 고장을 유형별로 분류하였다. 하지만 본 논문에서는 역 전파 신경 회로망과 다층 서포트 벡터 머신을 분류기로 사용함에 있어 역 전파 신경 회로망은 신경망을 구성하는 입력 뉴런 수, 은닉 뉴런 수, 학습 알고리즘에 의해 분류 성능이 달라지며, 다층 서포트 벡터 머신은 커널 함수로 사용한 가우시안 방사 기저 함수의 표준 편차 값에 따라 분류 성능이 달라지는 점을 고려하여 여러 가지 조건하에서의 실험을 통해 높은 분류 성능을 보이는 설정 방법을 제시하였다. The use of induction motors has been recently increasing with automation in aeronautical and automotive industries, and it playes a significant role. This has motivated that many researchers have studied on developing fault detection and classification systems of an induction motor in order to minimize economical damage caused by its fault. With this reason, this paper proposed feature vector extraction methods based on STE (short-time energy)+SVD (singular value decomposition) and DCT (discrete cosine transform)+SVD techniques to early detect and diagnose faults of induction motors, and classified faults of an induction motor into different types of them by using extracted features as inputs of BPNN (back propagation neural network) and multi-layer SVM (support vector machine). When BPNN and multi-lay SVM are used as classifiers for fault classification, there are many settings that affect classification performance: the number of input layers, the number of hidden layers and learning algorithms for BPNN, and standard deviation values of Gaussian radial basis function for multi-layer SVM. Therefore, this paper quantitatively simulated to find appropriate settings for those classifiers yielding higher classification performance than others.

Monitoring of inter-turn insulation failure in induction motor using advanced signal and data processing tools

Detection of stator winding inter-turn insulation failure at early stages is crucial for promoting safe and economical use of induction motors in industrial applications. Whereas major insulation failures involving larger percentages of winding are easily discernible from magnitude of supply current, minor inter-turn insulation failures involving less than 5% of turns often go undetected. The present contribution reports experimental results of minor faults due to inter-turn insulation failures in stator windings of induction motor under different loading conditions being analyzed using data and signal processing tools combining Park's Transform and Cross Wavelet Transform. Rough Set Theory (RST) based classifier has been used for fault severity monitoring.

An EMC evaluation of the use of unshielded motor cables in AC adjustable speed drive applications

The most common solution for modern adjustable speed drives (ASD) is the use of induction motors (IM) fed by voltage-source inverters (VSI). The inverter generates a pulsewidth modulated (PWM) voltage, with dv/dt values of about 6 kV//spl mu/s or even more. In three-leg inverters for three-phase applications the occurrence of common-mode voltage is inherent due to asymmetrical output pulses. As a result, for electromagnetic compatibility (EMC) reasons, in most applications shielded cables are used between the inverter and the motor, implying high installation costs. The present paper discusses the use of cheaper, unshielded cables from an EMC point-of-view. A new method for measuring electromagnetic interference (EMI) from unshielded cables is proposed and measurement results are presented. The level of EMI is evaluated in different situations: without an output filter, with a classical LC output filter and with an advanced output filter with dc link feedback. It is concluded that, from an EMC point of view, unshielded cables can give very good performance provided that a common-mode (CM) output filter is used.

A research survey of induction motor operation with non-sinusoidal supply wave forms

The developments in the power electronics field have lead to an ever-increasing use of static switching devices to control the torque and speed of ac motors. Invariably, the output voltage and current waveforms of these devices contain numerous harmonics and these harmonics have detrimental effects on the motor performance in form of derating and torque pulsation, especially at low speed. The order and magnitude of these harmonics depend on the design as well as nature of load being supplied. The extensive research has been underway for a long time in order to assess the effects these harmonics have on induction motor performance, and to investigate the various issues related to the use of induction motor to improve the drive performance and reduce the losses. This paper, therefore, presents a comprehensive review of research and developments in the induction motor operation with non-sinusoidal supply waveforms since its inception. Attempts are made to highlight the current and future issues involved in the development of induction motor drive technology to impart good dynamic stability with improved performance. A list of 167 research publications on the subject is also appended for a quick reference.

Optimizing current control performance in double winding asynchronous motors in large power inverter drives

The operation of AC drives in applications requiring high overload capability imposes hard working conditions on the electronic switching devices. The use of induction motors with two stator windings, fed by two inverter modules, allows large power rating in variable speed drives for high performance applications. This paper shows the structure and the main features of a field-oriented control for a double winding motor, fed by two GTO inverters. The operational results of an 850 kW drive, working as a melt pump in a polyethylene plant, are reported in order to describe the obtained performances.

Can an AC (alternating current) electrical system replace the present DC system in the automobile? An investigative feasibility study. I. System architecture

In the aerospace industry, the 400-Hz AC system replaced the DC system, and the latest trend in aerospace industry involves a combination of mixed AC and DC electrical system applications. With more and more equipment in the newer automobiles and a corresponding increase in power requirement, it is anticipated that in the not too distant future higher voltage and/or some different architecture will be necessary in order to have an efficient electrical system. The question addressed in this paper is whether an alternative single- or three-phase AC electrical distribution and load system could replace the present DC system and, if so, what kind of architecture should be used. In this paper, first the electrical system architecture is described. Other issues discussed include the comparison of relative cost and size issues arising due to: (1) additional DC-AC power electronic converter hardware; (2) changes in the wiring system; and (3) the use of induction motors which can adequately handle the motor loads without any added power and/or control electronics at certain chosen frequency(ies). It is shown that for a three-phase system there will be a net total saving. The benefits of the AC system are not just based on cost, but on reliability and robustness as well. It seems that a replacement of the present electrical system with a three-phase AC system could be a reasonable step toward alternative electrical system selections.

Quantitative Study on the Electromagnetic Vibration in a Squirrel-Cage Induction Motor.

1.Introduction Squirrel-cage induction motors have been widely used as constant-speed motors in many industrial applications for a long time. However, high performance speed control technology has advanced in recent times, with the result that vector-controlled squirrel-cage induction motors have been widely applied to variable speed driving systems (1),(2). Together with this increase in the use of induction motors have come increased requirements for much lower vibration and acoustic noise levels. As a result, a great deal of research on methods of reduction for both acoustic noise and vibration has been published (3)-(5). In squirrel-cage induction motors, the airgap magnetic flux density includes many harmonic components (other than fundamental component) due to harmonic magnetomotive force caused by winding and harmonic airgap permeance caused by slot opening. Harmonic torque, loss(6) and radially-directed electromagnetic forces (mentioned in this paper) are generated due to interaction of the airgap with the harmonic magnetic flux density. It is not the probability of harm, but rather the scale of the harm potentially due to these harmonics that makes them worthy of study. Therefore, it is necessary to quantitatively determine the factors which affect these harmonics (and their associated vibration and acoustic noise levels) with which to base design improvements for lower-noise squirrel-cage induction motors. In this paper, concept for quantitative study of the radially-directed electromagnetic forces which cause both vibration and acoustic noise will be offered and quantitative analytical expression will be shown. We will show the main factors causing the generation of these radially-directed electromagnetic forces, at the same time we shall describe how to perform quantitative calculations with respect to electromagnetic forces, vibration levels, and flexural vibration of the stator core. Then, the utility of the theoretical models will be evaluated by comparing calculated theoretical values against actual measured values. These include: variations in amplitude of vibrations in the stator core vibrations due to variations in, for example, supply frequency and supply voltage.

Optimum Use of Induction Motors in Tanzanian Industries

Optimum Use of Induction Motors in Tanzanian Industries

The magnetic noise of polyphase induction motors

THE WIDE USE of induction motors in the home, the office, and the factory requires that they both look and sound well. The pleasing, if not handsome, appearance of present-day motors attests to the skill of the “appearance design” experts who have worked with motor engineers in recent years. Now, there is a growing demand that motors should have good “sonance design” also. They should give out a steady pleasing hum, just loud enough to show that they are performing their duties properly, but not loud enough to be noticed.

The Magnetic Noise of Polyphase Induction Motors [includes discussion

The wide use of induction motors in the home, the office, and the factory requires that they both look and sound well. The pleasing, if not downright handsome, appearance of present-day motors attests to the skill of the appearance-design experts who have worked with motor engineers in recent years. There is now a growing demand that motors should have good "sonance design" also. They should give out a steady pleasing hum, just loud enough to show that they are performing their duties properly, but not loud enough to be noticed. This paper describes the magnetic forces that cause the magnetic noise of polyphase induction motors, and the corresponding modes of motion of the motor cores and frames. Approximate equations are derived for the decibel sound levels that motors of normal design may be expected to produce, and variations due to core and frame resonance are discussed. The two principal types of magnetic noise, due to the radial forces of the fundamental air gap field, and the tooth frequency pulsations of these forces, are considered separately.

Electric power equipment for steel plants

The rapid increase in the use of electric power equipment in steel plants in the United States during the last 3 decades is outlined briefly in this paper, and the principal types of apparatus now in use are discussed. Power generation and distribution equipment is considered briefly and the types of electric motors used in different kinds of main mill drives are outlined. Synchronous motor and d-c motors are shown to have largely superseded the use of induction motors.

Electric Power Equipment for Steel Plants

The rapid increase in the use of electric power equipment in steel plants in the United States during the last 3 decades is outlined briefly in this paper, and the principal types of apparatus now in use are discussed. Power generation and distribution equipment is considered briefly and the types of electric motors used in different kinds of main mill drives are outlined. Synchronous motor and d-c motors are shown to have largely superseded the use of induction motors.

Induction Motor Versatility Nature of Its Applications

I ODAY the induction motor bids fair to bring about another revolution of ideas as regards its use and capabilities. Heretofore, particularly in respect to the squirrel cage motor, it has been confined to rather restricted fields of application. Its starting characteristics and the need of special starting devices were against it. Now, limited-starting-current motors such as those employing double cage rotors are overcoming these starting objections. The use of these “across-the-line” motors has encouraged the idea of throwing standard motors directly on the line as well as the use of induction motors for applications demanding frequent starting or reversing. Formerly the squirrel cage motor was looked upon as one to be applied only for constant speed service; today there are many applications where the operating range covers wide variations in speed.

Induction motor versatility the nature of its applications

I ODAY the induction motor bids fair to bring about another revolution of ideas as regards its use and capabilities. Heretofore, particularly in respect to the squirrel cage motor, it has been confined to rather restricted fields of application. Its starting characteristics and the need of special starting devices were against it. Now, limited-starting-current motors such as those employing double cage rotors are overcoming these starting objections. The use of these “across-the-line” motors has encouraged the idea of throwing standard motors directly on the line as well as the use of induction motors for applications demanding frequent starting or reversing. Formerly the squirrel cage motor was looked upon as one to be applied only for constant speed service; today there are many applications where the operating range covers wide variations in speed.