Direct torque control of inverterfed induction machine allows high dynamic performance by means of very simple control schemes. Abstracta threephase squirrelcage induction motor is used as a propulsion system. Design of direct torque controller of induction motor dtc. The advantages and shortcomings of threelevel voltage source inverters in locomotive traction electric drives are highlighted in relation to twolevel ones. The simplicity and excellent dynamic performance of direct torque control dtc make induction motor im drives attractive for many applications that require. The direct torque control is one of the excellent strategies available for torque control of induction machine. Direct torque control dtc is used to control the motor. A novel direct torque control scheme for induction machines with space vector modulation. Both approaches are simulated for dual threephase induction motor dtpim.
Introduction in many industrial applications, direct torque control dtc of induction motor is wellknown control method which provides fast dynamic response compared with other control methods like field oriented control. The block diagram shows that dtc has two fundamental sections. With dtc, no tachometer or encoder is needed to feed back speed or position signals. The reason is, the restriction of free flow of xy components. An ac motor is an electric motor driven by an alternating current ac. Fivephase induction motor dtcsvm scheme with pi controller. Nov 14, 2015 direct torque control of an induction motor is established by survey of operation regimes of traction electric drives to thoroughly satisfy the requirements for a traction electric drive. Implement direct torque and flux control dtc induction. Key wordsdual threephase induction motor, direct torque control, fast torque response, sensorless vector control, voltage source inverter, switching strategy optimisation. This paper describes an induction motor drive for use in electric propulsion. Direct torque control technique for voltage source. The motor is controlled at different operating conditions using a direct torque. In scalar control, which is based on relationships valid in steady state, only the magnitude and frequency of voltage, current, and flux linkage space vectors are. Thus, their control techniques have received a lot of interest.
Its main principles have been introduced and deeply explained. Keywords direct torque control, fuzzy logic control, space vector modulation, induction motor control. Introduction the positive aspects of induction motor, like its simple construction, reduced cost, reliability and reduced cost is the reason why it is being widely. The fuzzy direct torque control of induction motor based on space vector modulation c proceedings of the third international conference on natural computation, haikou, china. It shows that the proposed method reduces torque ripple by 60% peak to. Pdf design of direct torque controller of induction. This four switch based inverter fed direct torque control of three phase induction motor is simulated using matlabsimulink software. Dec 10, 2017 torque in an induction motor pulavarthi kishore. This invention relates to an intake system for fourcycle engines and more particularly to an improved induction system that offers significantly better low and midrange performance than prior art sys.
The transient analysis of both threephase and singlephase induction motors. It has been more than a century since the principle of the operation of induction motors was discovered. Drm092, 3phase ac induction vector control drive with single. Direct torque control technique for voltage source inverter. An efficient method of induction motor control is the direct torque control dtc. Direct torque and flux regulation in sensorless control of an. Pdf direct torque control of induction motor with matrix. This curve provides us with information about the operation of an induction motor.
Direct torque control dtc is one method used in variable frequency drives to control the torque and thus finally the speed of threephase ac electric motors. Different methods for direct torque control of induction motor fed. In this control strategy, efficiency is optimized by adjusting the magnetic flux of the motor. Direct torque control of induction motor copy magnetic. In addition to these parameters like d and q stator current, d and q axis flux, torque and speed are obtained graphically. Induction motor, vector control, direct torque control, pi controller, anti windup pi controller. It is considered as an alternative to field oriented control foc technique. The motor is mounted in a test rig that allows one to control the torque applied to the motor shaft and to measure both rpm and torque. The dtc induction motor drive ac4 block represents an improved scalar control drive for induction motors with direct torque and flux control.
Direct torque control of brushless dc drives with reduced torque ripple. Torque response improvement of direct torque controlled. Index termsdirect torque, control, motor drive, induction motor. The fuzzy controller is designed to have three fuzzy state variables and one control variable for achieving direct torque control of the induction machine89, there are three variable input fuzzy logic controllers, the stator flux error, electromagnetic torque error, and. To make the control input vs appear explicitly in the. Metwally, mahrous ahmed faculty of engineering, electrical engineering, dept, taif university, ksa h.
Article information, pdf download for loss minimization of induction machines. Proposed method the speed control of induction motor is done using direct torque control with four switch three phase inverter. The results obtained show that both fast torque and optimal switching logic can be obtained. Abstract in this paper, a sliding mode speed observer for direct torque controlled dtc induction motor drives is developed. Direct torque control scheme for dualthreephase induction motor.
The efficiency of direct torque control for electric. Control of induction motor fed with inverter using direct. Induction motor drive, modeling of induction motor, vector control, field orient control, direct torque control, and fuzzy applications. It covers the modern theory of induction motor applications and control methods. With the help of f ield oriented control scheme decoupling of two components of stator currents i. Direct torque control of induction motor using svm matlab. A voltage source inverter vsi supplies the motor and it is possible to control directly the. Torque slip characteristics of induction motor full guide. The second control goal employed in the torque control of im is the tracking of the rotor flux magnitude. Direct torque control of induction motor using svm. Introduction the history of electrical motors goes back as far as 1820, when hans christian oersted discovered the magnetic effect of an electric current. So, the input power is also called as torque in synchronous watts, or the torque is 0 t p. Direct torque control dtc of im using space vector pwm.
As a result, the induction motor cannot produce torque near synchronous speed where. Simulation study of two torque optimization methods for direct. Direct torque control of sixphase induction motors using. The proposed control strategy is based on a designed cost function given as. Fuzzy direct torquecontrolled induction motor drives for traction.
The voltage is defined from the dcbus voltage and inverter switch positions. K direct torque control of induction motor using space. A 6 kw three phase induction motor has been used in order to run and evaluate the developed model. Fivephase induction motor dtcsvm scheme with pi controller and ann controller. Direct torque control of induction motor shodhganga. In a direct torque controlled induction motor drive supplied by current source inverter it is possible to control directly the modulus of the rotor fluxlinkage space. The torque is also known as electromagnetic torque. Direct torque control dtc is an emerging technique for controlling pwm inverterfed induction motor im drives. In this case the squared norm of rotor flux ia 2 is to be kept at a desirable, e. It is considered as an alternative to field oriented control technique. Case 2 the characteristics of the motor for free acceleration of the motor. It allows the precise and quick control of the im flux and torque without calling.
Optimised direct torque control of induction motor for. Introduction in early days dc machine played an important role in variable speed drives applications since the magnetic flux and torque can be easily controlled independently by. Stator flux and torque control the induction motor stator flux. At present, induction motors are the dominant drives in various industries. Pdf direct torque control of induction motor drives. Dtc, an advanced control technique of induction motor drives yielding superior performance.
The optimal value of dither frequency and magnitude is found out under free running condition. Oct 26, 2012 the main aim of direct torque control strategies is to effectively control the torque and flux of induction motor. Direct torque control is supposed to be one of the best controllers for driving any induction motor. The efficiency of direct torque control for electric vehicle behavior improvement 3 fig.
The specifics of the application electric vehicle require fast response and high efficiency for the drive. Jul 17, 2014 these effects overheat the machine at low speed. Direct torque control of induction motors fed by a single. Jun 10, 20 this model simulates direct torque control of a three phase induction motor.
Direct torque control principle direct torque control dtc is an optimised ac drives control principle where inverter switching directly controls the motor variables. The first industrial motors of this type were constructed at the end of the nineteenth century and soon gained the favor of users who appreciated their raggedness, simplicity and relatively low manufacturing cost compared to dc commutator motors. Improvements in direct torque control of induction motors. Pdf simulink model of direct torque control of induction. T s t 2 3 2 3 sa b sc e i a i b in principle thedtc method selects one of the six nonzero and two zero voltage vectors of the inverter on the basis of the instantaneous errors in torque and stator flux magnitude. Different motors are suitable for different applications. Novel torque ripple minimization algorithm for direct. Pdf direct torque control strategy of induction motors.
The efficiency of direct torque control for electric vehicle. In this project, a dtc model has been developed and tested using a matlabsimulink package. The direct torque control is one of the excellent control strategies available for torque control of induction machine. At full load, the machine has a rated speed of 1440 r. It is quite cumbersome to control an induction motor im because of its poor dynamic response in comparison to the dc motor drives. Speed estimator is implemented to control of speed of motor along with the torque. The electromagnetic torque of a threephase induction motor can be written as 2, 4. Although ac induction motors are easier to design than dc motors, the speed and the torque control in. Direct torque control of three phase induction motor using. Zafari for revising this paper is appreciated as well. Induction motors are currently used in many industrial applications. Torque equation of an induction motor the developed torque or induced torque equation in a machine is defined as the torque generated by the electric to mechanical power conversion. The dtc scheme comprises of flux and torque switching table.
In scalar control, which is based on relationships valid in steady state, only the magnitude and frequency of. It is also demonstrated in this thesis that the method of dtc also allows the independent and decoupled control of motor torque and motor stator flux. The proposed control structures have a cascade free structure that consists of a vector of electromagnetic torque, flux and mechanical. Analysis of torque control under various load conditions is simulated. The measured input values to the dtc control are motor current and voltage. Model predictive base direct speed control of induction motor drive. You should also make a dc measurement of stator winding linetoline resistance using a dmm. In this study, direct torque control dtc of induction motor is evaluated based on space vector modulation.
In normal operating conditions between pullout speed and synchronous speed we have nearly a linear relationship between the torque and the slip. Classical direct torque control has inherent disadvantages such as. Journal of low frequency noise, vibration and active control. At the synchronous speed slip s0 so, the motor will produce zero torque. Direct torque control of induction motors with stator flux. High performance direct torque control of induction motor. Speed control of direct torque controlled induction motor drives for electrically driven marine propell er has been presented. Introduction the induction motor or asynchronous is the most widely used electrical drive. Neural network technique is used as speed controller of induction m. Sign in here to access free tools such as favourites and alerts, or to. Direct torque control of an induction motor file exchange. Space vector trajectory is also plotted to observe the performance. In dtc the torque and flux of an induction motor can be controlled directly by applying a suitable voltage vector to the stator of an induction motor.
Induction motors analysis and torque control bahram amin. The principal of direct torque control using fuzzy logic fdtc. Speed sensorless direct torque control of induction motor drives. Modeling and analysis of sixphase induction motor is investigated in. This paper deals with the implementation of direct torque control technique on induction motors i.
Pdf neural network technique for direct torque control. Novel torque ripple minimization algorithm for direct torque. T s t 2 3 2 3 sa b sc e i a i b in principle thedtc method selects one of the six nonzero and two zero voltage vectors of the inverter on the basis of the. A new torque and flux control scheme called the direct torque control dtc has been introduced for induction motors. An efficient method of induction motor control is the direct. This involves calculating an estimate of the motors magnetic flux and torque based on the measured voltage and current of the motor. The estimation value of flux and its phase angle is calculated in expression. An887, ac induction motor fundamentals microchip technology. In this paper direct torque control dtc is applied for induction motor control fed by three phase pwm inverter. Direct torque and flux control of three phase induction motor. The machine speed is controlled in closed loop by direct torque control strategy. Dtc is a method to control machine with utilizing torque and flux of motor. Direct torque and flux control of three phase induction. Direct torque control of induction motor fed from hybrid.
Direct torque control method made the motor more accurate and fast torque control, high dynamic speed response and simple to control. Direct torque and flux regulation in sensorless control of. In this paper, we propose two approach intelligent techniques of improvement of direct torque control dtc of induction motor such as fuzzy logic fl and. A new technique for the torque control of induction motors was developed and presented by i. Two control approaches using fuzzy dtc are developed and applied to adjust the. This developed torque in the motor differs from the actual torque available at the terminals of the motor, which is almost equal to the friction and windage. Fourswitch inverterfed direct torque control of three phase. Speed estimation vectorcontrolled induction motor drive based on. Direct torque control dtc, as a powerful control method, for five and sixphase induction motor presented for the first time in, respectively. Record all nameplate information for the induction motor. Assessment of direct torque control for induction motor drives. May 20, 2018 and from this relation we deduce that curve.
Hence with the help of f ield oriented control strategy its. Sensorless direct torque control of induction motors. Simulink model of direct torque control of induction machine. Smooth speed control of induction motor is not possible. Direct torque control of induction motors for electric. Loss minimization of induction machines during torque transients.
This thesis is mainly devoted to the investigation of speed control methods for three phase cage induction motors with particular emphasis being given to direct torque control dtc improved techniques. Direct torque control technique for voltage source inverter fed induction motor drives. Direct torque control design for three phase induction motor. Introduction in early days dc machine played an important role in variable speed drives applications since the magnetic flux and torque can be easily controlled independently by the stator and rotor currents respectively 1.
Introduction first of all let us start by understanding some important concepts related to the induction motor. Torque equation of an induction motor starting torque. Direct torque control, induction motor drive, space vector modulation, switching table. A mathematical model of a multimotor system fed by. Free master software users manual, freescale semiconductor, 2004. The starting torque is obtained by putting s 1 in equation hence, it is clear from the above equation that the starting torque is proportional to the square of the stator applied voltage. Induction motor drive design based on efficiency optimization and drive loss minimization.