Cascade control speed control of three phase induction. Free download induction motor seminar ppt, pdf report. But in some industrial applications, speed control of motor is required. Pdf different methods of speed control of threephase. Speed control of three phase squirrel cage induction motor written by athul s chandran, akhil g augustine, alvin valantine published on 20150408 download full article with reference data and citations. Keywords cycloconverter, split phase induction motor i.
Speed control technique of single phase induction motor. Nehrir, speed control of threephase induction motor by stator voltage control ieee transactions on industrial electronics and control instrumentatio n, may 1975. The three phase induction motor has following advantages. A three phase induction motor is basically a constant speed motor so its somewhat difficult to control its speed. Speed control of three induction motor by vf method for batching motion system.
There are two basic reasons for the use of singlephase motors rather than 3phase motors. Speed control of induction motor ac motor speed control. This method is also called the tandem control and obsolete now. Speed of a dc shunt motor can be varied very easily with good efficiency, but in case of induction motors, speed reduction is accompanied by a corresponding loss of efficiency and poor power factor. The ability of varying any one of the above three quantities will provide methods of speed control of an induction motor. There are following methods of speed control of three phase induction motor. The speed control of induction motor is done at the price of reduce in efficiency and low power factor.
There are many methods in use to start 3phase induction. 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. Generally an induction motor operates at almost constant speed as the load is varied. A 3phase induction motor uses current delivered in three phases in a sequence into the coils of a stator to create a rotating magnetic field. The difference between the preset speed and the actual speed is fed to the rectifier. So obviously the speed of an induction motor can be controlled by varying any of three factors namely supply frequency f, number of pole p or slip s. If we inject emf which is in opposite phase with the rotor induced emf, rotor resistance will be increased. Pdf speed control of three phase induction motor using. The synchronous speed of the motor at rated conditions is. Speed control of three phase induction motor by vf method for. The control methods for induction motors can be divided into two parts. As the torque at zero rotor speed is nonzero, the induction motor is selfstarting.
Aspalli, speed control of three phase induction motor by vvvf method using g7a drive international journal of recent technology and engineering ijrte vol. Be careful it can hurt to tangle with a threephase motor. Explain starting methods of 3 phase induction motor. Three phase induction motor induction is one of the widest spread motor due to its robustness, simple construction, no need for complex circuits for starting. A 3 phase induction motor can be used for different applications with various speed and load requirements.
Here we will see a detailed article related to the starting methods of threephase induction motor. Speed control methods for a 3 phase induction motor. Accordingly, the inverter changes the frequency and adjusts the speed of the motor. Before discussing the methods to control the speed of three phase induction motor one should know the basic formulas of speed and torque of.
Speed control of induction motors the speed of an induction motor is given as n 120fp 1s. Stator voltage control of threephase induction motor is a popular scheme used in industry for torque and speed control. Therefore, speed control of 3 phase induction motor can be achieved by following methods. With several available speed control techniques, this paper presents a new. An induction motor can be defined as the ac electric motor device in which a power source fed by the alternating current with the help of a primary winding. This will cause excessive stator current and distortion of the stator flux wave. Vf is the most common method of speed control in open loop. How to control the speed of 3 phase induction motor quora. The speed of a threephase induction motor driving a given load is determined by matching the torquespeed characteristics of the motor and load, as shown in fig. This induces an electric field in a coil or squirrel cage to drive a rotor. For reason of economy, most houses, offices and also rural areas are supplied with single phase a. Speed control of induction motor using vf technique phase i a thesis. The power drawn from the rotor terminals could be spent more usefully.
A three phase induction motor is basically a constant speed motor. It should be noted that, speed control from rotor side is only applicable for slip ring induction motor. The three phase induction motor or synchronous motor is used as ac drive. Speed control methods of various types of speed control. There are three speed control motor product groups. Speed control of induction motor using pwm technique. Induction motor seminar ppt, pdf report study mafia. The synchronous speed of an induction motor is given by the relation shown below. Methods of speed control of induction motor electrical. Thus it is obvious that to change speed of machine any one parameter either frequency or no of poles are to be changed. Pwms, one less than the three required to control a 3phase induction motor. Speed control of induction motor 7 ways to control.
Introduction speed control of induction motor is necessary in industrial applications. Hi all, so im working on a project titled controlling the speed of a single phase induction motor. The speed of induction motor depends on various factors, like supplied voltage, frequency, number of poles. This application note also covers the basics of induction motors and. Types, construction and principle of operation, 3 phase induction motor, general phasor diagram, equivalent circuit, power and torque relations, condition for maximum torque, circle diagram. Pdf speed control of induction motors kamakhya basumatary. Different methods of speed control of threephase asynchronous. It is based on freescales 56f800e microcontrollers. Speed control of induction motor using cycloconverter. The speed of the rotor is fed back to the differentiator. Constant vf control of induction motor this is the most popular method for controlling the speed of an induction motor. It is widely used in industry due to low cost and rugged construction. The main methods employed for speed control of induction motors are as follows.
Speed control of induction motor part 1 by, supply. Different speed control methods of induction motor are explained below. There are several methods for the speed control of induction motor. In this paper, various methods of speed control of induction asynchronous motors such as variable rotor resistance, variable stator voltage, constant volts hertz. Currently the use of three phase induction machines has been increased tremendously in industrial applications due to several methods available to control the speed and torque of the motor. Speed control of induction motor by variable frequency control variable frequency control is a method which is used to control the speed of an induction motor. The ac speed control motor unit that uses the most popular singlephase capacitorrun induction motor, the. Variable voltage variable frequency speed control of. The difference in speed between rotor, the synchronous speed and the rotating.
Before discussing the methods to control the speed of three phase induction motor one should know the necessary formulas of speed. Speed of a 3 phase induction motor can be controlled by these methods. The rotor speed of an induction motor is given by the equation shown below. An induction motor is practically a constant speed motor, that means, for the entire loading range, change in speed of the motor is quite small. Speed control of a three phase induction motor using pwm. Various induction motor speed control methods advantages. As in above method, if the supply frequency is reduced keeping the rated supply voltage, the air gap flux will tend to saturate. Following are the various methods of speed control of induction motor achieved from rotor side. Speed control of three phase induction motor electrical. The synchronous speed of induction motor depends upon supply frequency and the number of stator poles. Speed control of induction motor ac motor speed control methods an induction motor is basically a constant speed motor, that means, for the entire loading range, change in. Speed control of 3phase induction motor microchip technology.
So by changing the supply frequency, the number of stator poles and slip we can change the speed of 3 phase induction motor. Scalar control is the term used to describe a simpler form of motor control, using nonvectorcontrolled drive schemes. The performance evaluation of the motor under the different switching strategies. Speed control of induction motor by variable frequency control. Today i will discuss very important topic speed control of induction motor. In this paper, a new method of speed control for the single phase induction motor is introduced to overcome the disadvantages of the conventional methods. A three phase induction motor is mostly a constant speed motor so its fairly not easy to control its speed. In this paper, various methods of speed control of induction asynchronous motors such as variable rotor resistance, variable stator voltage, constant voltshertz.
Low cost, low maintenance, simple construction, reliability and high efficiency. While researching on the internet i came across this one circuit that proposes a model that uses a microcontroller and a triac circuit and a. The basic idea of an electric motor is to generate two magnetic fields. The synchronous speed and therefore, the speed of the motor can be controlled by varying the supply frequency. A successful salesman for general electrics motor division once remarked to one of your instructors that, when asked by a customer how a motor. Apart from using the heat generated in meaning full ways, the slip ring output could be connected to another induction machine. The speed control of induction motor is done at the cost of decrease in efficiency and low electrical power factor. An induction motor is practically a constant speed motor, that means. Speed control of an induction motor there is a various method of speed control of an induction motor. New method for speed control of single phase induction. Why is speed control in an induction motor, difficult. Speed control of 3phase induction motor using rotor.
In this post let us see what are the various methods to control the speed of induction motor. The windings on the rotor are terminated to three insu. 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. Firstly threephase induction motor drive system is simulated in various modes using matlabxilinx, then. Cycloconverters are used in very large variable frequency drives with ratings from few. An843, speed control of 3phase induction motor using.
Nehrir proposed a technique for speed control of threephase induction motor by stator. In this video i describe about the speed control of inductuon motor by using different methods like, 1. Currently the use of threephase induction machines has been increased tremendously in industrial applications due to several methods available to control the speed and torque of the motor. Speed control techniques of induction motors can be broadly classified into two. Also lets get to know the methods which are used to control the speed of squirrel cage. Speed control of three phase induction motor electrical4u. Microcontroller based control of three phase induction motor using pwm technique. Introduction this application note describes the design of a 3phase ac induction motor drive with volts per hertz control in closedloop vhz cl. Speed control of induction motor using vector control. In this application note, we will generate a third pwm in software, using a general purpose timer and an io pin resource that are readily available on the picmicro microcontroller. Constant vf method is commonly used for constant and variable speed control of induction motor6.
Speed control of three phase squirrel cage induction motor. Variable voltage variable frequency control of threephase induction motor in closed loop is the significant feature of the thesis work. Our speed control motor packages include the motor, the driver controller, and a potentiometer which allows for easy speed control adjustment. This necessitates the requirement of having methods for speed control of induction motor. The synchronous s peed of the motor at rated conditions is. Speed control methods of various types of speed control motors. Before discussing the methods to control the speed of three phase.
Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. In this paper, different types of speed control methods for the single phase induction motor are described. Speed control of 3 phase induction motor a 3 phase induction motor is practically constant speed motor provided that applied parameters supply, frequency etc. With the increase in stator voltage, the motor speed will increase.
In ac rotating machine speed of machine is govern by the equation n120fp. We can vary the motor speed by varying the stator voltage. Stator voltage 3 phase motor speed control methods in this 3 phase motor speed control method, only stator voltage is varied to vary the speed of the motor, the stator frequency is kept constant. The 3phase set of currents, each of equal magnitude and with a phase. The ac speed control motor unit that uses the most popular singlephase capacitorrun induction motor, the small and highly efficient brushless dc motor unit. These techniques depend on varying the stator ac voltage to control the speed of threephase induction motor. The rotor will constantly be turning to align its magnetic field with that of the stator field. Three phase induction motor or ac motor is started by itself but we require some starter or other methods for proper starting and controlling induction motor. In this method, the magnitude of the main winding current and its angle are controlled to control the motor speed, as well as to increase the starting torque at all speed settings.