Variable Speed Induction Motor Research Articles

An experimental demonstration of hybrid fuzzy-fuzzy space-vector control on AC variable speed drives

This work presents the experimental demonstration of a hybrid fuzzy-fuzzy controller speed control of a squirrel-cage induction motor variable speed drive based on the space-vector pulse width modulation technique by means of digital signal processing. In particular, two features of field-oriented control were engaged to design a hybrid fuzzy-fuzzy controller, namely the current and frequency. In order to overcome the limitations of the field-oriented control technique, the principle of the hybrid fuzzy-fuzzy controller is introduced in the course of the acceleration–deceleration stages to regulate the speed of the rotor with the help of a fuzzy frequency controller. Conversely, a fuzzy stator current magnitude controller was involved during the steady-state. The results revealed that the control approach has the ability to deliver a practical control solution in the presence of diverse operating conditions.

High-performance multicell series inverter-fed induction motor drive

The multilevel voltage-source inverter (VSI) topology of the series multicell converter developed in recent years has led to improved converter performance in terms of power density and efficiency. This converter reduces the voltage constraints between all cells, which results in a lower transmission losses, high switching frequencies and the improvement of the output voltage waveforms. This paper proposes an improved topology of the series multicell inverter which minimizes harmonics, reduces torque ripples and losses in a variable-speed induction motor drive. The flying capacitor multilevel inverter topology based on the classical and modified phase shift pulse width modulation (PSPWM, MPSPWM) techniques are applied in this paper to minimize harmonic distortion at the inverter output. Simulation results are presented for a 2-kW induction motor drive and the results obtained demonstrate reduced harmonics, improved transient responses and reference tracking performance of the voltage in the induction motor and consequently reduced torque ripples.

Sensorless control of variable speed induction motor drive using RBF neural network

High power of modern digital signal processors and their decreasing prices enable practical implementation of different speed estimators which are used in the sensorless control of AC drives. The paper describes application possibilities of artificial neural networks for the sensorless speed control of the A.C. induction motor drive. In the sensorless control structure of the A.C. drive, there is implemented the speed estimator which uses two different artificial neural networks for speed estimation. The first speed estimator uses a multilayer feedforward artificial neural network. Its properties are compared with the speed estimator using a radial basis function neural network. The sensorless A.C. drive was simulated in program Matlab-Simulink. The main goal of many simulations was finding suitable structure of the artificial neural network with required number of neuron units which will ensure good control characteristics and simultaneously will enable a practical implementation of the artificial neural network in the digital signal processor control system.

Efficiency Improvement of Induction Motor Variable Speed Drive Using a Hybrid Fuzzy-fuzzy Controller

Abstract Induction motor (IM) variable speed drive efficiency is essential for a few reasons as energy conservation, economic saving and lessening of ecological contamination. This research represents a study of the efficiency improvement for the developed hybrid fuzzy-fuzzy controller (HFFC) scheme to gain control over the speed of an induction motor's variable speed drive (VSD). In order to overcome drawback of field oriented control (FOC) method, the principle of HFFC is based on set of rules to control speed of a rotor by utilizing fuzzy frequency controller during the accelerate-decelerate stage. Alternatively, a fuzzy stator current magnitude controller is used during steady-state stage. The two aspects (current and frequency) of FOC are engaged to design a scalar controller. The performance of the controller is observed by conducting a series of tests, and it can be concluded that the controller is efficient, reliable and insensitive towards the parameter variation in the system and motor robustness to load and noise disturbances.

가변 속도 유도 전동기에서 발생한 펄스 토크에 의한 회전축계의 비틀림진동 현상

가변 속도 유도 전동기에서 발생한 펄스 토크에 의한 회전축계의 비틀림진동 현상

Calculation algorithms for speed characteristics of an induction motor for variable speed drive and their possible use in problems of energy analysis

This article focuses on the use of speed characteristics in issues of the development of variable-speed induction motors. An algorithm for constructing a test electromagnetic calculation, which takes into account the influence of the main regulators of the control system and uses the basic design formulas and procedures of the known methods, is proposed. The algorithm solves the inverse problem concerning test electromagnetic calculation. Ways of using the proposed technique for the solution of practical tasks, which include the creation of speed characteristics, as well as finding the optimum power supply regime, are shown. Results of comparison of the design and experimental data are given.

Dynamic Harmonic and Reactive Power Compensation with an Adaptive Shunt Active Filter for Variable Speed Induction Motor Drive

Dynamic Harmonic and Reactive Power Compensation with an Adaptive Shunt Active Filter for Variable Speed Induction Motor Drive

Design of Unity Power Factor Controller for Three-phase Induction Motor Drive Fed from Single Phase Supply

This paper carves out the design of unity power factor controller for three phase variable speed induction motor drive. SPWM technique is used to improve the power factor of the system to unity and hysteresis controller is used for speed control of the drive. These control techniques lead to a unity power factor seen by the ac supply and minimize the power loss, audible noise, and motor torque ripple.  A

Sensor less Operation of CSI Fed Induction Motor Drive by Using MRAS

The underground mines, oil and gas industries need remote operation of vector controlled medium voltage variable speed induction motor drives with long feeder. The usage of voltage source inverters in such cases leads to motor over voltage and harmonic problems. The current source inverter (CSI) has no such problems to these applications because of its motor friendly voltages output. This paper proposes sensor less operation of a CSI fed induction motor drive and improves the speed estimation. The proposed model uses model reference adaptive system (MRAS) speed estimator requires motor voltage and currents as inputs. Direct measurement of motor voltages and currents are impractical for long feeder drives due to feeder length and safety of environmental precautions. Hence the motor voltages and currents are drawn from the inverter out. In this paper the flux estimation needed for MRAS speed estimation is proposed to observe the performance of the induction motor with sudden change of loads under steady state. This model is simulated in The model reference adaptive system contains two models they are stator model and rotor model. The speed of the machine is estimated by using the above two models (2). The inputs required for the model reference adaptive system is the voltages and currents. The speed is estimated from the calculation of rotor flux linkages in the stationary reference frame from the both stator and rotor models. The estimated speed is calculated from the error obtained by cross multiplication of the flux linkages produced in the two models (stator and rotor models) with PI controller. The estimated speed is fed back to the one of the input of rotor model. Rotor model is also called as adaptive or adjustable model and the stator model is called the reference model. The two models are designed in Simulink by using the following equations and the block diagram is represented as shown in fig.1. The equations of reference model as follows

The Fundamental Theory and Points of Attention for Variable Speed Induction Motor and Drive System (No.5)

The Fundamental Theory and Points of Attention for Variable Speed Induction Motor and Drive System (No.5)

Simulation of Electromagnetic Interference and its Mitigation in an Induction Motor Drive

This paper analyses the EMI issues associated with an induction motor drive circuit using IGBTs. The high frequency equivalent circuit of IGBT is modelled in MATLAB software and the waveforms plotted are corroborated with data sheet waveforms. A variable speed induction motor drive with six such IGBT sub system as the switching units is developed. The conducted EMI voltage is obtained with a Line Impedance Stabilization Network (LISN) between the EMI source and the power supplies. The measured values are compared with CISPR conducted emission limits. A filter is designed to eliminate the interference due to conducted EMI.

Fuzzy Logic Based Advance Speed Control of Induction Motor

The speed control of Induction motor is done using the advance AI Technique methods. In this System the vector control scheme in the stator flux oriented reference frame is used for controlling the variable speed Induction motor. For this the conventional Speed PI controller and Current PI Controllers are tuned and the responses are observed. The Conventional Speed PI Controller is then replaced by the Fuzzy Logic Speed Controller to observe the various responses of the system. The fuzzy Logic Speed Controller is designed and tuned in such a way to obtain better and fast sped responses of the system. Simulation results reveal that the fuzzy-controller improves the performance of variable speed Induction Motor in terms of speed and Power factor

Direct Torque Control of Reversing Voltage Topology Multi-Level Inverter Fed Induction Motor

Variable speed induction motor drives find applications in various industries. The normal Induction Motor drive has a closed loop speed control. Here, we use a Multi- Level Inverter (MLI), which has emerged as an alternative in the medium-voltage high-power control to feed the Induction Motor. The Multi-Level Inverter employs a new topology known as the reversing voltage topology (RVT). To generate output voltage with higher number of levels, this topology requires less number of components and less carrier signals for PWM implementation. The proposed induction motor drive structure offers reduced device count and a simpler power-bus structure when compared to a conventional five-level NPC and flying capacitor inverter fed induction motor drives. The Induction Motor is controlled by the scalar method of Direct Torque Control (DTC). This scheme is the direct control of the torque and stator flux of a drive by inverter voltage space selection through a look-up table to maintain speed at reference. Performance comparison for various voltage vector selections has been made. This technique has a comparable performance with that of vector controlled drives

Increasing Long-Belt-Conveyor Availability by Using Fault-Resilient Medium-Voltage AC Drives

Belt conveyors constitute an efficient and economical way for minerals and heavy-load transportation from mines to their destination, serving vital process units whose success depends on continuous operation. To meet important operational requirements, modern high-capacity conveyor systems are equipped with medium-voltage variable-speed induction motor drives. The reliability and service continuity of such drives play a critical role in the entire conveyor availability. This paper proposes an alternative to significantly improve the availability of the conveyor systems by using fault-resilient medium-voltage ac drives. Based on recent studies and the authors' experience, it is shown in this paper how the conveyor drive downtime can be dramatically reduced after an internal short circuit, keeping the overall cost to repair to a minimum and avoiding financial losses that can reach several million dollars.

Feedback controller design for variable voltage variable speed induction motor drive via Ant Colony Optimization

This paper deals with the development of feed back controller design for a voltage controlled induction motor drive employing an enhanced optimization algorithm derived from the principles of foraging of natural ants. A linearized incremental model of a voltage controlled induction motor drive is shown to exhibit parameter variation at different operating points of the drive system. A PI-controller derived at a typical operating point using traditional methods does not give satisfactory performance for a wide bandwidth of load and reference speed changes. The newly developed Ant Colony Optimization technique enforces continuous exploration of the solution space and identifies optimal controller structure. The development of optimization algorithm and its application to feed back controller design for a variable voltage induction motor drive is well documented in this paper. Experimental and simulation results are presented to validate the efficacy of the optimized controller.

Simulation and Implementation for the Speed Control System of Horizontal Continuous Casting Dragger for Copper

The levels of continuous casting process of copper and copper alloy billet have many advantages, such as taking small footprint, low investment and the shorter flow. Recently, it develops very quickly all over the world. This article designs the dummy body drive control system based on the DSP digital signal processing chips, inverter and variable speed induction motor, and uses the unique process that space vector pulse width modulation strategy can achieve continuous casting horizontal tractor’s four beats to realize continuous casting process’ high-quality, stable and reliable implementation. Early in the 19th century, German Bismarck had proposed a continuous casting process in his patent. The development of this method in the copper industry began in 1940s, the type of equipment went through belt type, vibration mold, vertical traction type, tilt casting type and Horizontal traction type [1, 2]. Now, horizontal traction, as the most popular method abroad, because its products don’t need straightening, and consistency of properties along the length and high density of grain lead to the improvements of mechanical properties and electrical properties, its superiority in product quality and production efficiency is obvious. The design combined the modern AC variable speed control and advanced SCM control technology and traction continuous casting process to design a Speed controller of horizontal continuous casting of copper traction motor, its performance is similar with to dummy industrial control computer and AC servo motor drive control system, but the configuration of the hardware is less than half the price.

INDIRECT FIELD-ORIENTED CONTROL OF FIVE-PHASE INDUCTION MOTOR DRIVES

Five -phase ac motor drives are nowadays considered for various applications, due to numerous advantages that they offer when compared to three-phase motors. Variable speed induction motor drives without mechanical speed sensors at the motor shaft have the attractions of low cost and high reliability. To replace the sensor, information of the rotor speed is extracted from measured stator currents and voltages at motor terminals. This paper proposes speed estimation method using model reference adaptive system (MRAS) to improve the performance of a sensorless vector controller of five-phase induction motor (IM). In the proposed method, the stator current is used as the state variable to estimate the speed. Since the stator current error is represented as a function of the first degree for the error value in the speed estimation, the proposed method can provide fast speed estimation and is also, more robust to variations in the parameters, compared with other MRAS methods. Consequently, this method can improve the performance of a sensorless vector controller in a low speed region and at zero-speed. The proposed method is verified by simulation using the Matlab/Simulink package. The performance of the proposed system is investigated at different operating conditions. The proposed controller is robust and suitable for high performance five-phase induction motor drives. Simulation results validate the proposed approaches.

Laboratory development of wind turbine simulator using variable speed induction motor

The conventional synchronous generators in wind energy conversion system are now getting replaced by variable speed induction generator to extract maximum power with wide range of wind speed limit. The design and performance of such systems requires a simplified digital simulator, especially for the development of a optimal control solution .The proposed work is to make a prototype of variable speed wind conversion system simulator for a required operational condition under variable wind speed. In this paper variable speed induction motor drive using scalar control is interfaced in wind energy conversion system as an alternative to make the real time wind simulator for wind energy researchers. The basic power curve from wind generator is carried out through d-SPACE and interface of induction motor through an inverter control system. The induction motor is operated in wide speed range using Volt /Hertz speed control scheme. The laboratory prototype consists of 3 kW, 415 Volt, 50Hz induction motor controlled by voltage source inverter for various wind speed. The paper demonstrates the steady state characteristics of wind turbine without dependence on natural wind speed using Volt/Hertz. The basic control strategy is implemented through hardware system. The result verifies that the wind turbine simulator can reproduce the steady state characteristics of a given wind turbine at various wind conditions.

Modified Euler integration based control of a five-phase induction motor drive

In principle, control methods for multi-phase machines are the same as for three-phase machines. Variable speed induction motor drives without mechanical speed sensors at the motor shaft have the attractions of low cost and high reliability. To replace the speed sensor, information of the rotor speed is extracted from measured stator currents and voltages at motor terminals. Vector-controlled drives require estimating the magnitude and spatial orientation of the fundamental magnetic flux in the stator or in the rotor. Open-loop estimators or closed-loop observers are used for this purpose. They differ with respect to accuracy, robustness, and sensitivity against model parameter variations. This paper analyses operation of a modified Euler integrationbased sensorless control of vector controlled five-phase induction machine with current control in the stationary reference frame. A linear neural network has been then designed and trained online by means of back propagation network (BPN) algorithm, differently from that in the literature which employs a nonlinear back propagation network (BPN) algorithm. The Artificial Neural Network (ANN)-Model Reference Adaptive System (MRAS) based sensorless operation of a three-phase induction machine is well established and the same principle is extended in this paper for a five-phase induction machine. Performance, obtainable with hysteresis current control, is illustrated for a number of operating conditions on the basis of simulation results. Full decoupling of rotor flux control and torque control is realised. Dynamics, achievable with a five-phase vector controlled induction machine, are shown to be essentially identical to those obtainable with a three-phase induction machine. International Journal of Engineering, Science and Technology, Vol. 2, No. 6, 2010, pp. 218-230

Development of a new fault-tolerant induction motor control strategy using an enhanced equivalent circuit model

Variable speed induction motor drives operating with an open circuit phase fault generally have a high harmonic current content and impose a large torque ripple on the load. These effects result from the unbalanced nature of the faulted machine, and under these conditions, the effects of machine and converter non-linearities become more pronounced. It is important to include these non-linearities when modelling drive systems which may operate under fault conditions, and developing fault ride-through control algorithms. This paper proposes a modelling method for induction motor drives which includes machine saturation and space harmonics effects as well as inverter non-linearities, which does not require significant computation times. Results from an experimental test rig are presented to validate the model. The second part of the paper describes how the model was used to develop a new fault ride through control strategy for a voltage-fed vector controlled drive. Experimental results demonstrate the improved drive behaviour with an open-circuit winding fault when controlled with the new strategy.