Rotorflux orientation i d axis of coordinate system is. Robust speed control of induction motor drives using first. Field oriented control describes the way in which the control of torque and speed are directly based on the electromagnetic state of the motor, similar to a dc motor. The induction motor is made up of the stator, or stationary windings, and the rotor. Comparison between direct and indirect field oriented control of. In the direct scheme, the instantaneous position of rotor flux. Vector control of induction motor drives springerlink. Vector or field oriented control is based on control of magnitude and phase alignment of vector variables. Induction motor theory jerry bednarczyk, pe course content introduction the ac induction motor is well suited to applications requiring constant speed operation. An interesting feature for controlling the ac induction motor at low speeds is the patented pwm waveform distortion correction circuit. Currently, indirect field oriented control technique is one of the first choice controllers for highperformance induction motor drives, however, rotor speed or.
The numerical model of the squirrelcage, threephase induction motor is represented as a system of differential equations. Simulation of indirect fieldoriented induction motor. Anaheim automation offers industrial ac motors from 220w to 2200w, in 3phase operation at 220vac or 380vac. The electrical drive controls become more accurate in the sense that not only are the dc current and voltage controlled but also the three phase currents and.
In since its introduction in 1985, the direct torque control dtc 4, 5, 6, principle was widely used for induction motor drives with fast dynamics. When describing a three phase induction motor by a system of non linear equations, following assumptions are made. Tms320f2803x devices are part of the family of c2000 microcontrollers, which enable. Thus it is obvious that to change speed of machine any one parameter either frequency or no of poles are to be changed. Speed control of an induction motor there is a various method of speed control of an induction motor.
Pdf field oriented control of induction motor semantic scholar. The principle of field oriented control is based on the. Presented here is a robust system for switching onoff, varying the speed and direction of rotation of an industrial 3 phase induction motor using vfd and plc. Sensored field oriented control of 3phase induction motors. The content of this book is divided into three basic parts. An introduction there are various methods for the speed control of an induction motor. Working principle of an induction motor circuit globe. How to control the speed of an induction motor quora. Applied intelligent control of induction motor drives. Before discussing the methods to control the speed of three phase induction motor one should know the basic formulas of speed and. A softstart controller is used in threephase ac induction motors to reduce the load on the selfstarting motor and the current surge of the motor during startup. Integrating this motor type with a reliable controller became quite important for numerous industrial applications.
Induction motor, vector control, predictive control. Ac industrial motors are designed for applications requiring a threephase, highpower induction motor. View induction motor drives research papers on academia. The control performance of field oriented induction motor drive greatly depends on the correct stator flux estimation. Sensorless speed and position control of induction motor. The field orientation principle in control of induction. Keywords cycloconverter, split phase induction motor i. The power ratings of an industrial motor exceed those of a standard singlephase ac induction motor. Please refer to pdf documents in the motor control folder explaining the details and theoretical background. Compared with the existing highorder adrc based speed.
Each pwm is doublebuffered and includes interrupt controls. By using field oriented control, torque and flux of the induction motors can be controlled independently as in dc motors. Speed sensorless model predictive torque control of induction motor drive. The speed control of induction motor is done at the cost of decrease in efficiency and low electrical power factor. From the equation 1 it is clear that the motor speed can be changed by a change in frequency f, a number of poles p, and slip s. Fieldoriented control induction motor drive mathworks. With decoupling between the stator current components magnetizing flux and torque, the torque producing.
High performance speed sensorless control of threephase. The speed control of three phase induction motor from stator side are further classified as. The document an205408 smo based field oriented control of induction motor with speed sensor for fm3 microcontroller has been marked as obsolete. A theoretical background on field oriented motor control principle. Maher 1, walid emar1, mahmoud awad2 1electrical engineering dept. Find the percentage slip and number of poles of the induction motor. Line voltage control the torque developed varies with the square of the applied voltage. The key feature of the motor control dsp is the inclusion of pwm modules. The control of ac machine is basically classified into scalar and vector control. This is partly because the motor has an intrinsically simple and rugged structure and low manufacturing cost 1,2.
In order to study the performance of the system a simulation program was implemented using matlabsimulink software package. Implementation of field oriented speed sensorless control. Indirect field oriented control ifoc induction motor drives are used in high performance systems in various industrial applications due to their relative simple configuration, as compared to the direct torque controlled dtc technique. Depending on the motor, there can be significant torque pulsations when a singlephase induction motor is run at low speeds. Optimal control of induction motor using high performance.
In this post let us see what are the various methods to control the speed of induction motor. An984, an introduction to ac induction motor control using. We use here delta ac motor drive for its operation. He fieldoriented control method is widely used for induction motor drives. The rotor speed of an induction motor is given by the equation shown below. How does an ac drive control induction motor speed. Requests of very dynamic drives can only be accomplished by using vector control because the scalar control is too slow. Various automation processes in the industry need control of ac induction motors using ac drives. Introduction speed control of induction motor is necessary in industrial applications. Induction motor can be operated like a dc separately excited motor, if the control is considered in a rotating reference frame d eq e, where the sinusoidal variables appear as dc quantities in steady state. In these applications, a rota tional transducer such as a shaft encoder is used.
The most popular type is the 3phase, squirrelcage ac induction motor. Chans research interests are selfexcited induction generators, brushless ac generators, permanentmagnet machines, finite element analysis of electric machines, and electric motor drives control. The speed of an induction motor can be easily controlled by varying the frequency of the 3phase supply. For applications where high degree of accuracy in speed control is not required simple methods based on steady state equivalent circuit have been employed. In general, the induction motor is cheaper and easier to maintain compared to other alternatives. Induction motor is now called the racehorse of the industry 1. How ever, a rotational transducer cannot be mounted in some cases, such as motor drives in a hostile environment, highspeed motor drives, etc. As for electrical drives systems, mpc has been widely investigated for ac machines. Induction motors, industrys traditional workhorses, are particularly well. Ac motors, controllers, and variable frequency drives. This work focuses on the indirect field oriented control of induction motor. This speed control method is known as volts per hz.
Motor drive requirements practically speaking, control of a 3phase ac induction motor requires pulsewidth modulated control of the six switches of a 3phase inverter bridge connected to the motors stator windings figure 1. The fieldoriented control induction motor drive block represents a standard vector or rotor fieldoriented control drive for induction motors. Speed control of induction motor using cycloconverter. The obsolete version of this application note is still available with the below description but may not be complete or valid any longer. Vector control, also called fieldoriented control foc, is a variablefrequency drive vfd control method in which the stator currents of a threephase ac electric motor are identified as two orthogonal components that can be visualized with a vector. Vector control, also called fieldoriented control foc, is a variablefrequency drive vfd control method in which the stator currents of a threephase ac. The electromagnetic induction is the phenomenon in which the electromotive force induces across the electrical conductor when it is placed in a rotating magnetic field. The device is designed to control most motor types, including induction motors. Sensor field oriented control ifoc of threephase ac induction. One component defines the magnetic flux of the motor, the other the torque.
The fuzzy logic can compensate the system nonlinearities through human expertise. Fall 2005 ee595s electric drive systems 32 the basic idea te. Foc is the first technology to control the real motor control variables of torque and flux. The speed control loop outputs the reference electromagnetic torque and rotor flux of the machine. Various methods of speed control in three phase induction. Implementation of intelligent controllers in direct torque. Nonlinear model predictive control for induction motor drive. In most of the classic ac drives the generation of the three sine waves is based on motor electromechanical characteristics and on an equivalent model for the motor in its steady state.
Fieldoriented control is a strategy research for induction motor speed adjustment feeding by variable frequency converter 3. This adds to the cost and complexity of the drive system. The influence of the most important parameter variations e. Tzefun chan is an associate professor of electrical engineering at the hong kong polytechnic university, where he has been working for over 30 years since 1978. The induction motor is supplied by a space vector pulse. In the minor loop, the proposed impbased dob is applied. We know that t he speed of the induction motor is given by, from the above equation, the speed of the motor can be controlled by changing supply frequency and by changing number of poles in the stator. A three phase, 12 pole, salient pole alternator is coupled to a diesel engine running at 500 rpm. Induction motor ifoc based speedcontrolled drive with.
Aloof control the control can be installed remotely at a suitable location, keeping just the motor in the processing area on the contrary of hydraulic and mechanical varying speed systems. The recent intense interest in these systems has been spawned by the widespread transition from dc to ac drives in industry. In the indirect scheme, a model of induction motor is required to calculate the reference angular slip. In ac rotating machine speed of machine is govern by the equation n120fp. The field oriented control foc of induction motor provide one of the most suitable and popular speed control technique presently used. Induction motor drive, sensorless fieldoriented control, state. The pi control is simple and offers a wide stability margin, but it incorporates tuning,overshoot problems. A comparative study of fieldoriented control and direct.
Cost reduction direct on line starting of induction motors cause current peaks that harm the motor as well as other electric equipments linked to. Sensored field oriented control of 3phaseinduction motors bilal akin and manish bhardwaj abstract this application report presents a solution to control an ac induction motor using the tms320f2803x microcontrollers. Abstract the paper deals with the vector control and predictive control of the induction motor. Physical layout of induction motor in an induction motor induction refers the field in the rotor is induced by the stator currents and asynchronous refers that the rotor speed is not equal to the stator speed. At nasa lewis research center, we are currently working with an foc system which utilizes the pulse population.
Controlling 3 phase induction motor using vfd and plc. Singlephase motors can also be used, but they have limited performance in the lowspeed range. The field orientation principle fop constitutes a fundamental concept behind the modern technology of highperformance, vectorcontrolled drive systems with ac motors. The field orientation principle in control of induction motors. There are several methods for the speed control of induction motor. International journal of control science and engineering 2012, 23. Speed control of three phase induction motor electrical4u. For the vector control, the rotor flux oriented one is pointed out, with highlight on the voltage source inverter type.
There are more than one methods to control the speed of induction motor, you can choose one depending on your resources, efficiency required etc. Working principle of an induction motor the motor which works on the principle of electromagnetic induction is known as the induction motor. Controlling 3phase ac induction motors using the pic18f4431. Indirect field oriented control of an induction motor. This drive features closedloop speed control based on the indirect or feedforward vector control method. A three phase induction motor is basically a constant speed motor so its somewhat difficult to control its speed. Cycloconverters are used in very large variable frequency drives with ratings from few. Why is speed control in an induction motor, difficult. Comparison between direct and indirect field oriented.
Comparison between direct and indirect field oriented control of induction motor venu gopal b t research scholar, department of electrical engineering uvce, bangalore university, bengaluru abstract vector control, also called field oriented control foc, is a variable frequency drive vfd control method in which. The induction motor drive is based on the ifoc indirect field oriented control torque control algorithm. Various induction motor speed control methods advantages. In foc, the principle of decoupled torque and flux control are applied and it relies. Vector control of induction motor is based on torque control of separately excited dc motor 5. Threephase induction motor and classical ac drives. It supplies an induction motor ich has a full load speed of 144wh 0 rpm. An205408 smo based field oriented control of induction. Speed control of induction motor 7 ways to control.
Dynamic model in space vector form mathematical description of induction motor is based on space vector notation. With the advent of field oriented control foc, however, the induction motor has become an attractive option for these types of drive systems. An induction motor is presented as an electromechanical power converter, and basic relations between the electrical, magnetic and mechanical quantities in the motor will be explained. The threephase motor gives good torque performance at all operating speeds. A load torque observer is derived from the model predictive control law and integrated in the control. This reduces the mechanical stress on the motor and shaft, as well as the electrodynamic stresses on the attached power cables and electrical distribution network, extending the.
663 1213 936 1385 330 1182 416 1469 1109 1027 697 420 821 1058 15 593 1116 149 1511 1360 996 1477 1410 1106 726 413 1432 814 416 551 476 627 473 1244 191