At present, induction motors are the dominant drives in various industries. Due to introduction of delay in a practical system, it is found that the switching frequencies of the power switches are reduced. Improved reactive power capability of grid connected doubly fed induction generator 2. Different websites were used as a resource to develop the direct torque control. This four switch based inverter fed direct torque control of three phase induction motor is simulated using matlabsimulink software. It shows that the proposed method reduces torque ripple by 60% peak to peak compared to the case without dither injection. Kadjoudj, mohamed, taibi1, soufiane, golea, noureddine and benbouzid, hachemi, modified direct torque control of permanent magnet synchronous motor drives. A new technique for the torque control of induction motors was developed and presented by i. Direct torque control of induction motor drive using pifuzzy logic controller venkatesh. Direct torque control dtc of induction machine is known to have a simple control. Assessment of direct torque control for induction motor drives. The analysis shows that dither signal can substantially improve the voltage sag performance of a dfig wind farms and the amplitude of the dither signal is the main part to improve the performance, also it is very useful to reduce the torque ripples. Simulation of direct torque controlled induction motor.
Here is a list of 50 best ideas for selecting the seminar topics in the field of electrical engineering. Pdf an improved fpga implementation of direct torque control. The torque and flux references are tracked using hysteresis controllers and a switching table implemented with lut is used for selecting the optimum converters output. This model simulates direct torque control of a three phase induction motor. The direct torque control is one of the excellent control strategies available for torque control of induction machine. The direct torque control technique is most important and efficient technique to control the speed of induction motor. In this paper, a threelevel inverterfed induction motor drive operating under direct torque control dtc is presented. K improved direct torque control of induction motor with dither injection. Direct torque control of induction motor with improved switching scheme dr. Tech scholar, department of electrical and electronics engineering, siddhardha institute of engineering and technology, vinobha nagar, ibrahimpatnam, hyderabad, telangana 501506, india. Direct torque control of inverterfed induction machine allows high dynamic performance by means of very simple control schemes. In this paper, a novel technique for the direct torque control dtc of an induction motor is proposed, which overcomes the trouble of high torque ripple afflicting the conventional dtc technique. A triangular wave is used as dith this method minimizes flux and torque ripple in a threelevel inverter fed induction motor drive while the dynamic performance is not affected. Improved direct torque control of induction motor with dither injection.
Direct torque control dtc is one of the most excellent strategies of torque control of an induction machine. In this study, direct torque control dtc of induction motor is evaluated based on space vector modulation svm, it is able to reduce the acoustical noise, the torque, flux, current, and speed. Modern speed control technologies of ac motors robotic motors or special motors transformers. Over the years direct torque control dtc of induction motor emerged as an alternative to field oriented control of induction motor takahashi and naguchi, 1986. Voltage sag ride through using improved adaptive internal. Introduction induction motors ims are widely used in industrial, commercial and domestic app lications as they are simple,rugged, lowcost and easy to maintain. Review of improved direct torque control methodologies for.
Direct torque control, space vector modulation, induction motor i. Improved direct torque control for induction motor drives with rapid prototyping system article pdf available in energy conversion and management 4714. This involves calculating an estimate of the motors magnetic flux and torque based on the measured voltage and current of the motor. Direct torque control dtc of induction machines presents a good tracking for both electromagnetic torque and stator flux. Latest technical seminar topics for electrical engineering. Instantaneous frequency control with a view to control motor speed or position cannot be defined, and therefore, instantaneous torque control cannot be addressed by scalar control methods. Improve direct torque control of induction motor with. Vector control technique allows a squirrelcage induction motor to be driven with high dynamic performance, comparable with that of a dc motor. Direct torque control of induction motor using ann technique. Basics and types soft starting of motors with an improved power factor applications of fuel cells energy efficient motors improved direct torque control of induction motor with dither injection electrical ac and dc drives modern trends in machine. Direct torque control dtc is one of the most excellent control strategies of torque control in induction. Pdf improved direct torque control of induction motor with dither. Improve direct torque control of induction motor with dither injection k sirisha b.
Improve direct torque control of induction motor with dither injection. The aim is to control effectively the torque and flux. List of 50 seminar topics for electrical engineering. Due to arrangement of the stator coils and 3 phase supply applied to them, resultant magnetic field inside the motor is a vector constantly rotatin. S department of ece, skce, coimbatore, india department of ece, skce, coimbatore, india abstract direct torque control dtc of an induction motor fed by a voltage source inverter is a. The electromagnetic torque of a threephase induction motor can be written as 2, 4. Direct torque control induction motor drive with improved. Induction motors are widely used in many residential, commercial and utility applications.
Direct torque control of induction motor drive using pi. Improvements in direct torque control of induction motor. Drawbacks of vector control are complex control scheme and sensitivity to parameter variations 2. Implement direct torque and flux control dtc induction. Improved dtcdrivebased photovoltaic water pumping system. In a dtc induction motor drive, a decoupled control of torque and flux can be achieved by two independent control loops. It is quite cumbersome to control an induction motor im because of its poor dynamic response in comparison to the dc motor drives. Field oriented control foc and direct torque control dtc were chosen for simulation as they are standard induction motor control techniques 12. Therefore it is more suitable for the comparison to consider a direct field oriented control dfoc scheme, instead of a general foc scheme. This control scheme, as shown in fig1, depends only stator measurements. It is designed to provide fast and robust reactions of the drive even under the low frequency operation of power electronics. Space vector trajectory is also plotted to observe the performance. Improved direct torque control of induction motor with injection, proceeding in. Their combined citations are counted only for the first article.
Direct torque control dtc is a wellknown control scheme for induction motor drives, especially in high power applications. Torque control is direct in a dc motor, the magnetic field is created by the current through. Direct torque control dtc is one of such methods which gives performance comparable to vector control with very less. Conclusion although direct torque control offers robustness, simple construction and maintenance free operation, yet improvement using dither. It shows that the proposed method reduces torque ripple by 60% peak to peak compared to the case without dither injection, results in low acoustic noise and increases the. More than a decade ago, direct torque control dtc was introduced to give fast and good dynamic torque response. Direct torque control dtc for motor drive applications has been well established in both academia and industry. The speed control loop outputs the reference electromagnetic torque and stator flux of the machine. Fourswitch inverterfed direct torque control of three. Improving direct torque control of induction motor with.
Speed control of three phase induction motor electrical4u. Scalar control is the term used to describe a simpler form of motor control, using nonvectorcontrolled drive schemes. 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. The improved adaptive internal model control scheme delivers performance improvement as compared. Comparison of the field oriented and direct torque control. The speed control of induction motor is done at the cost of decrease in efficiency and low electrical power factor. Speed estimator is implemented to control of speed of motor along with the torque. Direct torque control dtc is one of such methods which gives performance. Induction motors are horse powers and widely in demand. Simulink model of direct torque control of induction machine h. Consider a 3 phase motor is supplied by 3 phase ac.
The torque developed by induction motor is directly proportional to angle. Direct torque control dtc, hysteresis current control hcc, space vector modulation svm, induction motor, switching losses. Direct torque control an overview sciencedirect topics. This drive features closedloop speed control using hysteresisband torque and flux controllers. It offers a simple control structure, fast response, and robust operation 35. There are few wellknown methods to estimate these parameters. The steady state as well as the dynamic performance of the drive is closely related to the efficient implementation of these two control algorithm. The dtc induction motor drive ac4 block represents an improved scalar control drive for induction motors with direct torque and flux control. An improved fpga implementation of direct torque control for induction machines. Improved direct torque control of induction motor with dither injection 553 figure 2. This paper presents a modified direct torque control based on combination of hysteresis current control and space vector modulation for induction motor drives. Direct torque control dtc is one of the most excellent control strategies of torque control in induction motor. Direct torque control dtc has become a popular technique for the control of induction motor drives as it provides a fast dynamic torque response and robustness to machine parameter variations.
Pdf improved direct torque control of induction motor. A triangular wave is used as dith this method minimizes flux and torque ripple in a threelevel inverter fed induction motor. Pdf torque ripple minimization for induction motor. Fpgabased torque and stator flux estimator for dtc induction motor drives. A three phase induction motor is basically a constant speed motor so its somewhat difficult to control its speed. In this paper, an incmpptbased dtc drive system is designed for pvbased induction motor drive to be used in water pumping. 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. Improved direct torque control of induction motor with dither injection article pdf available in sadhana 335. Before discussing the methods to control the speed of three phase induction motor one should know the basic formulas of speed and torque of three phase induction. Modified dtc schemes with new lookup table or the one with mixing of dither signals. Dtc is employed for high performance and quick response drives takahashi and ohmori, 1989. Pdf improved direct torque control for induction motor.
Sul, 1999 direct torque control of induction machine with variable amplitude control of flux and torque hysteresis bands, international conference on electric machines and drives iemd99,pp. Improved reactive power capability of grid connected doubly fed induction generator. Direct torque control of induction motor with improved. What are the latest seminar topics on power electronics. Improved direct torque control for induction motor drives. Improving direct torque control of induction motor with dither. In this paper dtc strategy with dither signal injection is. Attempts were made to find a control scheme which is less complex and gives good dynamic response for induction motor drives. Photovoltaic pv system has been now widely accepted as renewable energy source. Soft starting of motors with an improved power factor.
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