Stator Winding Of Induction Motor Research Articles

MULTIFUNCTION INDUCTION MOTOR

In this paper, we implemented the redesign of three phase induction motor such a way that motor can be used as multifunction. Stator winding of induction motor is redesigned and motor is used as phase converter as well as welding transformer.

THE COMPENSATION OF THE INFLUENCE OF INDUCTION MOTOR STATOR WINDINGS ASYMMETRY IN THE VECTOR-CONTROL SYSTEMS

It is presented the methods for compensation the influence of induction motor stator windings asymmetry on the characteristics of vector-controlled electric drive system. It is shown that the use of proposed control systems at the expense of introduction of additional compensation signals in closed control loops of the motor stator current allows to compensate the variable component of the electromagnetic torque or the variable component of the power consumption. Along with this, the use of the system for compensation of the variable component of the motor electromagnetic torque allows to decrease motor vibrations and the use of the system for compensation of the variable component of active power allows to decrease the heat overloads of the single motor phases, which increases the insulation life of the induction motor stator phases

Online technique for insulation assessment of induction motor stator windings under different load conditions

This paper presents a new condition monitoring system which is able to evaluate and diagnose the stator winding insulation deterioration (SWID) at its initial stages. During the last few decades, considerable efforts have been made in condition monitoring of SWID in induction motors. Nevertheless, an effective diagnosis technique that can lead to a fast and accurate detection of SWID shortly after its occurrence remains a challenge. A new modelling technique is introduced using finite element method which enables detailed simulation (two turn-to-turn resolution) of insulation degradation in a stator slot. Experimental setup is then used to validate the proposed modelling technique. The detail and approximation coefficients of the discrete wavelet transform are shown to provide effective detection of SWID within a few seconds after its occurrence. The proposed system continuously monitors the status of the induction motor and is able to detect the insulation deterioration of only 1.2% turns of phase winding when it starts to take place. The proposed method is only applicable to turn insulation failure detection. Its viability under different load conditions is validated for a small-sized induction motor with simulated turn insulation fault.

Wavelet Based Induction Motor Fault Diagnosis Using Zero Sequence Current

Induction motor stator fault is diagnosed by applying Discrete Wavelet transform on zero sequence components. The single phasing stator fault is created and diagnosed in the induction motor model developed in stationary reference frame, under varying load conditions. The stator inter-turn incipient fault is created and diagnosed in the induction motor experimental setup as well under no load condition. The qdo components are calculated from Park’s equations. The faults can be diagnosed from wavelet transform of the zero sequence current components. PSD is used for diagnosing the fault and the statistical value is used for verifying the result. The energy is calculated using Parseval’s theorem. The energy and the statistical data calculated from the wavelet coefficients of zero sequence current components are used as fault indicators. The energy value is able to reveal the fault severity in the induction motor stator winding. Power spectral Density along with Discrete Wavelet Transform plays very important role in diagnosing the fault.

Optimal Pulsewidth Modulation for Common-Mode Voltage Elimination Scheme of Medium-Voltage Modular Multilevel Converter-Fed Open-End Stator Winding Induction Motor Drives

Multilevel converter topologies for open-end stator winding medium-voltage (MV) induction motor drives have been researched from the last two decades. In this paper, a dual $n$ -level modular multilevel converter (MMC) topology has been proposed for open-end stator winding MV induction motor drives. The control requirements of the proposed system are low device switching frequency, minimal harmonic distortion of machine stator currents, elimination of common-mode voltages in machine stator windings, and maintaining floating capacitor voltages around their nominal value. Based on these requirements, an emerging modulation technique for MV induction motor drives known as synchronous optimal pulsewidth modulation has been developed for the proposed dual $n$ L-MMC topology. The laboratory measurements from a dual three-level MMC fed 1.5-kW open-end stator winding induction motor drive demonstrate the performance of proposed technique.

Frequency spectrum investigation and analytical diagnosis method for turn-to-turn short-circuit insulation failure in stator winding of low voltage induction motor

Low-voltage induction motors are widely used in the factories and are becoming very essential components for the industrial process. Improper diagnosis and condition monitoring of induction motor not only leads to high repair expenses but also cause extraordinary financial losses due to their unexpected downtime. In general, turn-to-turn short-circuit failure of stator winding due to their deterioration or damage of electrical insulation is one of the most feasible failures in motor drive systems. This paper proposes a diagnostic method based on amplitudes of characteristic frequency components of load current as features. These features are extracted by close analysis of frequency spectrum and its dependence on load current variation. This method has the advantage of low cost and short data processing time. Also to enhance the accuracy of diagnosis, a novel diagnostic method is proposed with the aid of Support Vector Machine. It is found that the proposed diagnosis method using the features and Support Vector Machine enables the detection of a slight insulation failure like one turn-to-turn short-circuit with practically accepted accuracy.

Induction motor inter-turn fault modeling and simulation using SSFR test for diagnosis purpose

This paper presents a new idea to establish a simplified model of the short-circuit turns (SCT), in the stator winding of the squirrel-cage induction motor (IM) using standstill frequency response test (SSFR). This method may offer more precision in parameters estimation independent of variations in motor or load operating conditions since it is at standstill test. However, high-performance field-oriented control, or diagnosis purpose of the IM requires accurate knowledge of the electrical parameters. Furthermore, we propose to model the IM by a multiple cage equivalent circuit (EC) that enables us to take into account the deep bar effect with accuracy.The specific advantage of the proposed method that we can create a true SCT at several levels using fault simulator in order to estimate the EC model parameters in each case of fault severity, with a low probability of risk to the machine being tested, and a relatively modest expense.At the first time the healthy machine is identified and experimentally validated, then the models have been successfully used to study the transient and steady-state behavior of the IM with SCT fault, which a practically oriented scientific value.

A Hybrid Nine-level Inverter Topology for an Open-end Stator Winding Induction Motor

In this article, a new hybrid nine-level inverter topology for an induction motor with an open-end stator winding is proposed. In the proposed topology, one end of the open-end winding is fed by a three-phase five-level inverter, and the other end is connected to a conventional three-phase two-level inverter. The three-phase five-level structure is realized by cascading a three-level flying capacitor inverter with capacitor-fed H-bridge in each phase. In the proposed topology, a total of 17,576 space vector combinations are available; hence, the capacitor voltages can be maintained at desired levels using switching redundancies. As compared to conventional topologies that require 48 switches, the proposed topology requires only 30 switches and completely eliminates the requirement of clamping diodes, which are required in a neutral point clamped inverter. Also, it requires only two capacitors per phase, whereas the nine-level flying capacitor inverter requires 28 capacitors per phase. In case of fault in any H-bridge, the system can be operated as a five-level inverter at its full power rating and improves the reliability of the inverter. The performance of the proposed system has been experimentally investigated on a 1.5-kW open-end stator winding induction motor, and results are presented.

Fault Identification in the Stator Winding of Induction Motors Using PCA with Artificial Neural Networks

Three-phase induction motors are the main element of electrical into mechanical energy conversion applied in the industries. Due to its constant usage, added to adversities such as thermal, electrical and mechanical, these motors can be damaged causing unexpected process losses. Among the drawbacks of occurrences commonly presented for this equipment, approximately 37 % are related to short circuit in the stator coils. Hence, this article proposes an alternative approach for stator fault identification in induction motors through the discretization of the current signal, in the time domain, applying a variable optimization technique of principal components analysis (PCA) and artificial neural networks (ANNs) types multilayer perceptron (MLP) and radial basis function. Experimental results are presented with data gathered from an experimental workbench, considering various supply conditions and also under a wide load variation, by using the amplitude of the current signals in the time domain. Moreover, the MLP network presented the best results and the PCA technique provided a considerable reduction in the number of ANNs inputs, and in general, the classification results were comparable to the results obtained when the networks inputs considered the technique employing downsampling of 30 points to represent the current signals using half-cycle of the waveform.

Turn-to-turn insulation failure diagnosis of stator winding of low voltage induction motor with the aid of support vector machine

Turn-to-turn short-circuit of stator winding due to deterioration of electrical insulation is one of the most probable faults in motor drive systems. This paper proposes two diagnostic methods to detect the fault based on Support Vector Machine. In the first method, magnitude and phase of load currents at fixed rotating speeds are considered as features reflecting winding condition. It is found that the method is effective particularly in slight insulation failure like one turn-to-turn short-circuit. Classification of winding condition, i.e. specification of number of short-circuit turns, is also achieved by this method. In the second method, only magnitude of load currents is treated as feature aiming at diagnosis available when load current varies. The method also has the advantage of low cost and short data processing time. It is found that two turn-to-turn short-circuit can be diagnosed with practically acceptable accuracy. An appropriate choice of the two methods should be recommended depending on the goal as well as circumstance of diagnosis.

Evaluation of stator winding faults severity in inverter-fed induction motors

Three-phase induction motor are one of the most important elements of electromechanical energy conversion in the production process. However, they are subject to inherent faults or failures under operating conditions. The purpose of this paper is to present a comparative study among intelligent tools to classify short-circuit faults in stator windings of induction motors operating with three different models of frequency inverters. This is performed by analyzing the amplitude of the stator current signal in the time domain, using a dynamic acquisition rate according to machine frequency supply. To assess the classification accuracy across the various levels of faults severity, the performance of three different learning machine techniques were compared: (i) fuzzy ARTMAP network; (ii) multilayer perceptron network; and (iii) support vector machine. Results obtained from 2.268 experimental tests are presented to validate the study, which considered a wide range of operating frequencies and load conditions.

Condition Monitoring of an Induction Motor Stator Windings Via Global Optimization Based on the Hyperbolic Cross Points

The objective of condition monitoring of induction machines is to detect the incipient stage of a fault before serious damage occurs with high associated cost. Although the condition monitoring techniques have been intensively investigated in the last decades, research is still carried out in reducing cost and improving accuracy. This paper proposes a novel method that enables efficient and accurate monitoring of the stator winding circuit fault. The proposed method is based on the sparse grid optimization method applied in the least squares estimation of the circuit parameters that characterize the condition of a fault incipient. The kernel of the method is the efficient search for the objective function minimum on the grid created by using the hyperbolic cross points (HCPs). The system cost and complexity are minimized since the proposed method only requires voltage and current signals recorded at a machine terminal without any invasive or additional hardware circuitry. The proposed HCP algorithm is robust to supply voltage unbalance and motor loading state. The validity and effectiveness of the proposed scheme is experimentally tested on a three-phase 800-W 380-V induction motor.

Online Detection of Induction Motor's Stator Winding Short-Circuit Faults

The main objective of this paper is to develop a new technique for detecting turn-to-turn short-circuit faults in one or two stator phases of an induction motor. Hence, modeling a turn-to-turn short-circuit fault in more than one phase and a phase-to-ground fault is the first novelty of this paper for calculating phase currents under faulty conditions. This strategy uses the extracted features from the corresponding three-phase current pattern in 3-D space. Identification of faulty phases and of the severity of the fault is the outcome of this technique. This technique is also capable of detecting a phase-to-ground fault. This method just requires current sensors that are available in most drive systems to provide good controllability, and details of the machine design are not necessary. Experimental results are included to show the ability of the proposed strategy for detecting and locating phase/phases under different faults and load conditions.

STUDY OF FREQUENCY-CONTROLLED ASYNCHRONOUS MOTOR UNITS TEMPERATURE VERSUS LOAD AND POWER SUPPLY TYPE

An equivalent thermal circuit is developed to form the basis of a system of heat-balance equations for a frequency-controlled induction motor. With the system of equations, temperatures of АИР 90В2 induction motor stator and rotor windings and cores are calculated and experimentally confirmed. The load dependence of the machine most heated units temperature at different forms of the supply voltage is revealed.

Performance of a load-immune classifier for robust identification of minor faults in induction motor stator winding

Performance of a load-immune classifier for robust identification of minor faults in induction motor stator winding

Performance of a load-immune classifier for robust identification of minor faults in induction motor stator winding

Reliable detection of induction motor stator winding insulation failure at its early stages is a challenging issue in modern industry. Insulation failure between small number of turns, involving less than 5% turns of phase winding are often indiscernible and detection becomes even more complicated when motor operates at varying load levels. In line-fed motors, supply voltage unbalance is another inadvertent issue which may tend to exhibit current signature similar to stator winding inter-turn insulation failure case. The proposed work presents a robust system, to identify severity of stator winding insulation faults when an induction motor with random wound stator winding works under such operating conditions. In the present work, various features obtained from time, frequency, timefrequency, and non-linear analysis of stator currents at various stator winding short circuit faults and supply voltage unbalance conditions for different load levels have been studied. A Support Vector Machine based Recursive Feature Elimination (SVM-RFE) algorithm is used to identify the features which can provide discrimination information related to severity of fault level, independent of supply voltage unbalance and immune to load level variations. Among the extracted features, features obtained through Detrended Fluctuation Analysis (DFA) are found to be most robust for this purpose. Finally a Support Vector Machine in Regression mode (SVR) has been formed to identify winding failures employing the optimum number of features selected through SVM-RFE technique.

Detection of the Short-Circuit Faults in the Stator Winding of Induction Motors based on Harmonics of the Neighboring Magnetic Field

Based on the time domain finite element analysis of the electromagnetic field, this paper studies the signature of the short-circuit faults inside the stator winding in the magnetic field outside induction motors. The detection of the such a fault is based on the evaluation of the output voltage of coil sensors placed in the motors neighbouring and the comparison of amplitudes of harmonics of this voltage for the healthy and faulty operation states.

Analysis by Simulation of the Over-voltages in PWM-Inverter Fed Induction Motors

The aim and content of the present work consists of the over voltages at induction motor terminal, the voltage distribution in the stator winding of induction motor confronted by fast rising voltage, the primary objective of this research work is to develop a simulation model of PWM Inverter, cable and induction model in MATLAB or EMTP software. The system model is used to identify the over voltages as well as the distribution and magnitude of fast rising (steep fronted) voltage in the stator winding of electrical machines fed from PWM inverters. Voltage reflection analysis analyzed at the motor terminal considering different cable length between motor and inverter as well as rise time. 

Loss Minimization for Form-Wound Stator Winding of a High-Speed Induction Motor

Resistive losses in the form-wound stator winding of a high-speed induction motor (HSIM) are minimized in the design stage by using Differential Evolution (DE). Time-discretized finite-element analysis (FEA) serves as a tool to offer electromagnetic losses in the machine for the optimization process. Temperature rise of the machines is fast checked during the optimization by using a thermal network model. Insulation thicknesses and power factor are other constraints in the algorithm. Time consumption of using time-discretized FEA is still a problem when a large number of variables or motor dimensions is required for the optimization algorithm. To reduce the number of required variables, the influence of stator dimensions on the electromagnetic losses is analyzed by using the Taguchi approach. From this evaluation, the important stator parameters to be varied during optimization algorithm are determined. Finally, form-wound stator winding with a minimum loss for a HSIM is obtained within certain limitations.

Analysis and control of dual stator winding induction motor

Analysis and control of dual stator winding induction motor The paper presents the mathematical models of dual stator squirrel-cage induction motor, formulated in phase coordinate system and in general transformed space vector form. The two types of models of dual stator induction motor are considered. The control systems of field-oriented control (IFOC and DFOC) and direct torque control (DTC) of the dual stator induction motor have been described and discussed.