Model Of Induction Motor Research Articles

Bifurcation diagrams in estimated parameter space using a pruned extreme learning machine

We propose an algorithm to estimate parameter spaces by using a pruned extreme learning machine, but without using principal component analysis, and we plot bifurcation diagrams in the estimated parameter spaces to visualize changes in system patterns. The estimation of parameter spaces can predict changes in the behavior of a system when its parameters are changed. It can be very helpful to adjust the optimal parameters of unknown systems. In this paper, we estimate the dimension of parameter spaces using the singular values of trained synaptic weights and the parameter spaces based on the method proposed by Bagarinao etal., using a pruned extreme learning machine. We motivate this use of a pruned extreme learning machine through numerical experiments, with the estimation of the dimension of parameter spaces for various systems, and we show that the proposed method can successfully plot bifurcation diagrams in the estimated parameter spaces. In addition, we show the results of a bifurcation diagram in the estimated parameter space for maps that are nonlinear-in-parameters, since Bagarinao etal. limited their method to linear-in-parameters maps. In particular, we estimate the parameter spaces for a mathematical model of induction motor drives and for a model of vegetation biomass in ecosystems, which are both nonlinear-in-parameter maps corresponding to real-world systems.

Offline Interturn Fault Diagnosis Method for Induction Motors by Impedance Analysis

In this paper, a new offline interturn fault (ITF) diagnosis method for induction motors is presented. The proposed method is based on impedance imbalance in the stationary d-q plane. First, to show the impedance imbalance, an induction motor model is presented with an ITF circuit loop and fault resistance. Then, six impedance components in the stationary d-q plane are defined, depending on the excited phase windings. With fast Fourier transform (FFT) filtering applied to the six impedance components in the d-q plane, the second-order impedance magnitudes are obtained. From the magnitude, the ITF and the faulty phase can easily be detected. Moreover, a specific faulty winding among the faulty phase windings can be identified. To verify the proposed method, finite-element analysis (FEA) and experimental results are presented for an induction motor having an ITF.

A Prediction-Based Current Sampling Scheme Using Three Resistors for Induction Motor Drives

In the traditional three-resistor-based current sampling scheme, the sampled currents will become inaccurate when the duration of zero-voltage vectors of an inverter is too short, which leads to a limited modulation index (MI). To overcome this problem, an improved three-resistor sampling method is proposed by establishing a predictive current model of an inverter load, which is that of an induction motor on the synchronous rotating frame for the demonstration purpose in this paper. The principle of this method is detailed in the paper. Then a simulation model of a vector-controlled induction motor drive that utilizes the proposed current sampling scheme is built in the Simulink environment. Finally, the experiment on the new sampling scheme is performed in both steady-state and dynamic conditions. The results verify that the existing current sampling problems can be solved effectively and the motor can perform well with higher MI under the new scheme. As a result, the loading capacity of the system can be enhanced notably.

Nearly Constant Switching Space Vector Based Hysteresis Controller for VSI Fed IM Drive

A constant switching frequency hysteresis controller based on current error space vector (CESV) for two-level voltage source inverter fed induction motor (IM) drive is proposed in this paper. Here the stator voltages along the α - and β -axes are estimated using current error information and steady-state model of IM. Estimated stator voltages, switching dwell times, and instantaneous voltage error vectors are used in the online hysteresis boundary computations. The steady-state CESV boundaries and the phase voltage normalized harmonic spectrum of the proposed hysteresis controller at different speeds resembles that of a constant switching frequency voltage-controlled bus clamping pulse-width modulation-based drive. The proposed controller exhibits adjacent voltage vector switching, fast dynamic response under transient conditions, and has a simple controller implementation. The superior performance of the proposed controller is simulated using MATLAB/Simulink platform and experimentally verified on a three-phase 2.2 kW IM drive.

Sliding Mode Control of Induction Motor Drive Based on Feedback Linearization

ABSTRACTIn this paper, sliding mode control theory is demonstrated to design and control the rotor speed and rotor flux of the feedback linearized induction motor (IM) drive. Dynamic equations of the IM in stationary reference frame are linearized using feedback linearization control technique. Direct differentiation method is being used for the linearization of dynamic model of IM. First, rotor speed and flux are decoupled through proportional-integral (PI) regulator and the resultant controlled variables are fed to the feedback linearization controller. To improve the dynamic performance of the motor, sliding mode flux and speed controllers are proposed. The model has been simulated using MATLAB/Simulink and validated experimentally using dSpace1104 controller board, inverter, and IM in the laboratory. Results clearly indicate the effectiveness of the proposed controller over PI controllers at different operating conditions such as load disturbance and speed reversal is analysed and compared in real time.

Двухканальная термодинамическая модель асинхронного двигателя для систем тепловой защиты

Двухканальная термодинамическая модель асинхронного двигателя для систем тепловой защиты

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.

2-D quasi-static Fourier series solution for a linear induction motor

PurposeThis paper aims to present a method for calculating electromagnetic fields, eddy currents and forces for a quasi-static two-dimensional (2-D) model of linear induction motors (LIMs) where the primary side is modeled as a collection of individual coils.Design/methodology/approachAn analytical solution using Fourier series is derived for a general source with current excitations residing in an airgap and moving relative to a conducting plate and back iron. Ideal magnetic material with infinite permeability is used to model the primary iron above the primary source and the back iron below the conducting plate.FindingsThe analytical solution is compared to a commercial 2-D finite element analysis (FEA) simulation for validation and then compared to a 2-D FEA model with a more detailed geometry of the LIM. The analytical model accurately predicts LIM thrust even though the geometry of the primary core is simplified as an infinitely long flat slab. 2-D frequency FEA can be used successfully to predict in motion LIM performance.Originality/valueThe analytical solution presented here models the primary excitations as individual discrete coils instead of current sheets, which all existing models are based on. The discrete coils approach provides a more intuitive and realistic model of the LIM.

Estimation of load torque in induction motors via dynamic sliding mode control and new nonlinear state observer

This study conducts load torque estimation in an induction motor (IM) with uncertainty using a dynamic sliding mode controller (DSMC) that suppresses chattering using an integrator or a low-pass filter placed before the control signal of the system. Hence, the dimension of the augmented system in DSMC is larger than the dimension of the original system, thus leading to an increase in the number of system states. These new state variables should be determined to control such a system. To address this problem, a new nonlinear state observer (NSO) is suggested and utilized in this study. The proposed method is independent of the uncertainty bound of the system, but the system output must be accessible. These subjects are important in practical implementations. Lyapunov theory is applied to validate the stability of the proposed DSMC and NSO methods. Then, the boundedness of the closed-loop signals is concluded from the stability of the proposed techniques. The validity of the proposed approach is evaluated using an IM model. By using DSMC and NSO, we can simultaneously control the IM and estimate its load torque. In particular, the external bounded load torque signal is compensated by the input control signal of the motor. Simulation results illustrate the advantages of the proposed approach.

Fuzzy – PI controller to control the velocity parameter of Induction Motor

The major application of Induction motor includes the usage of the same in industries because of its high robustness, reliability, low cost, highefficiency and good self-starting capability. Even though it has the above mentioned advantages, it also have some limitations: (1) the standard motor is not a true constant-speed machine, itsfull-load slip varies less than 1 % (in high-horsepower motors).And (2) it is not inherently capable of providing variable-speedoperation. In order to solve the above mentioned problem smart motor controls and variable speed controllers are used. Motor applications involve non linearity features, which can be controlled by Fuzzy logic controller as it is capable of handling those features with high efficiency and it act similar to human operator.This paper presents individuality of the plant modelling. The fuzzy logic controller (FLC)trusts on a set of linguistic if-then rules, a rule-based Mamdani for closed loop Induction Motor model. Themotor model is designed and membership functions are chosenaccording to the parameters of the motor model. Simulation results contains non linearity in induction motor model. A conventional PI controller iscompared practically to fuzzy logic controller using Simulink.

Dynamic characteristic of electromechanical coupling effects in motor-gear system

Dynamic characteristics of an electromechanical model which combines a nonlinear permeance network model (PNM) of a squirrel-cage induction motor and a coupled lateral-torsional dynamic model of a planetary geared rotor system is analyzed in this study. The simulations reveal the effects of internal excitations or parameters like machine slotting, magnetic saturation, time-varying mesh stiffness and shaft stiffness on the system dynamics. The responses of the electromechanical system with PNM motor model are compared with those responses of the system with dynamic motor model. The electromechanical coupling due to the interactions between the motor and gear system are studied. Furthermore, the frequency analysis of the electromechanical system dynamic characteristics predicts an efficient way to detect work condition of unsymmetrical voltage sag.

Approach to Computer Implementation of Mathematical Model of 3-Phase Induction Motor

This article discusses the development of the computer model of an induction motor based on the mathematical model in a three-phase stator reference frame. It uses an approach that allows combining during preparation of the computer model dual methods: means of visual programming circuitry (in the form of electrical schematics) and logical one (in the form of block diagrams). The approach enables easy integration of the model of an induction motor as part of more complex models of electrical complexes and systems. The developed computer model gives the user access to the beginning and the end of a winding of each of the three phases of the stator and rotor. This property is particularly important when considering the asymmetric modes of operation or when powered by the special circuitry of semiconductor converters.

Induction motor speed control using varied duty cycle terminal voltage via PI controller

This paper deals with the PI speed controller for the three-phase induction motor using PWM technique. The PWM generated signal is utilized for voltage source inverter with an optimal duty cycle on a simplified induction motor model. A control algorithm for generating PWM control signal is developed. Obtained results shows that the steady state error and overshoot of the developed system is in the limit under different speed and load condition. The robustness of the control performance would be potential for induction motor performance improvement.

The Squirrel-Cage Induction Motor Model and Its Parameter Identification Via Steady and Dynamic Tests

One of the most important bases for designing robust closed-loop controllers applied to induction motor with high performance is establishing its mathematical model and state observers, as well as the parameter identification with high accuracy. In this paper, a step-by-step mathematical model of the squirrel-cage induction motor is described at αβ coordinate frame where the parameters are defined in detailed form; the rotor flux linkages and load torque are estimated via an asymptotic observer; the induction motor parameter identification is performed via a data acquisition board, applying dynamic and steady-state tests. Inductances of the induction motor model are calculated using the proposed relationships between the magnetically coupled circuit and equivalent circuit model. The mathematical model, state observers, and parameter identification procedure of squirrel-cage induction motor are validated via comparison of simulation signals with their corresponding real-time signals. This validation is made experimentally by a steady-state test, where load conditions are changed via a dynamometer which is belt coupled with the squirrel-cage induction motor.

Design of Ladder-Slit Secondaries and Performance Improvement of Linear Induction Motors for Urban Rail Transit

In order to improve the performance of linear induction motors for urban rail transit, the ladder-slit secondary is designed, and the performance of linear induction motors with the ladder-slit and flat-solid secondary is calculated and compared. First, for the ladder-slit secondary, the slot combination, widths of the secondary conductor, and side bar are designed. Second, the finite-element model of the linear induction motor with the ladder-slit secondary is developed, and the influence of vertical forces on widths of secondary conductors is presented. Third, the eddy current and the transversal air-gap flux density are compared when the ladder-slit and flat-solid secondaries are applied, respectively. Finally, experiments are carried out by test lines to validate the calculated results of the force and efficiency. It shows that the ladder-slit secondary can reduce the edge effect and improve the performance.

Improved Field-Oriented Control for PWM Multi-level inverter-Fed Induction Motor Drives

<p class="Abstract"><em><span lang="EN-US">T</span></em><span lang="EN-US">his paper proposes a new approach to ensure the torque decoupled to the rotor flux of an induction machine based on the Field Oriented Control (FOC). The suggested method consists of inserting into the conventional d-q synchronous current controller, coupling terms of motor and multi-level inverter models. Making, the dynamic response of stator current components decoupled as well as the rotor flux and torque. In this paper, the mathematic model of an induction motor and multi-level inverter are first derived. Then, the synchronous current controller and modulation strategy for high power inverters are investigated. Finally, the validation through implementation and simulation of a 4.16 kV electric drive with MATLAB/Simulink and SimPowerSystems is performed. The model simulated in this paper includes an induction motor, nine-level cascaded H-bridge inverter and a carrier based space vector pulse-width-modulation.</span><span lang="EN-US">The results of the simulations of each method has been recorded and the comparison results reveal that the proposed method effectively maintains the rotor flux decoupled to the torque.</span></p>

Influence of motor cable on common-mode currents in an inverter-fed motor drive system

Induction motor drive systems fed by cables are widely used in industrial applications. However, high-frequency switching of power devices will cause common-mode (CM) voltages during operation, leading to serious CM currents in the motor drive systems. CM currents through the cables and motors in the drive systems can cause electromagnetic interference (EMI) with the surrounding electronic equipment and shorten the life of induction motors. Therefore, it is necessary to analyze the CM currents in motor drive systems. In this paper, high-frequency models of unshielded and shielded power cables are formulated. The frequency-dependent effects and mutual inductances of the cables are taken into account. The power cable parameters are extracted by the finite element method and validated by measurements. High-frequency models of induction motors and inverters are introduced from existing works. The CM currents at the motor and inverter terminals are obtained, and the influence of the cable length and cable type on the CM currents is analyzed. There is a good agreement between the experimental results and the CM currents predicted by the proposed models.

Parameters Identification of Induction Motor Model Based on Manufacturer Data and Sequential Quadratic Programming

In order to precaution and control the transient voltage stability of the receiving-end system, it is very necessary to quickly and accurately calculate the model parameters for induction motor synthesis load. There are several methods to obtain the model parameters of induction motor, in which, estimating the model parameters of induction motor using for power system stability analysis according to the nameplate data is a significant promising approach with potential application. In this paper, a new optimized mathematical model for identification of induction motor single-cage and double-cage parameters are proposed, it’s overcome the deficiency of artificially adding approximate constraints in parameter identification of induction motor models from induction motor manufacturer data. Minimization of the induction motor efficiency deviation is taken as the goal and important induction motor performance indicators, such as the stator current, the input reactive power, the maximum electromagnetic torque and the starting parameters, are equal to their manufacturer values are regarded as constraints, the sequential quadratic programming (SQP) is used to solve the nonlinear problem. The proposed new mathematical model and algorithm were verifed on a sample of 6 induction motors of different capacity, manufacturers, and rated voltage. The induction motor performance characteristics supplied by the manufacturer and used to identification parameters of induction motor are then calculated, using the equivalent circuit estimated parameters themselves. In all the studied cases, the calculated induction motors performance indexes are found to be in excellent agreement with the manufacturer data. Comparison with other methods shows that the induction motor model parameters obtained by this method can reflect the working characteristics of induction motor single-cage and double-cage model more accurately.

Simulation of three-phase induction motor using nonlinear model predictive control technique

In this paper, nonlinear model predictive control (NMPC) has been used to control an induction motor (IM). The IM model that is used in the control is third or fifth order model that is based in th...

Design and implementation of a MRAS sliding mode observer for the inverse of the rotor time constant of the induction motor

The paper presents an estimator for the inverse of the rotor time constant of the induction motor. Estimation is done using a sliding mode observer under the assumption that the stationary frame fluxes are known. With measured voltages, currents, and with known fluxes and speed, the paper develops an MRAS-type sliding mode observer. This works well under ideal conditions; however, if the speed is inaccurate or if the magnetising inductance saturates, the accuracy suffers. The paper develops a model for the saturated induction motor and attempts to also estimate the saturation level. In the second part, an observer with only a single set of feedback terms is developed. This is transformed into a sensorless observer by feeding it with a speed estimate (assumed inaccurate). The error in the estimated rotor time constant can be reduced by operating the motor drive with a low ratio of id to iq.