Inductionmotor speedchanging by poleamplitude modulation. Ninephase sixterminal poleamplitude modulated induction motor. Speed control of induction motor detailed explanation. Although it is basically a singlewinding, twospeed squirrel cage motor, the pam motor features one outstanding characteristic. Request pdf on dec 1, 2018, rohith and others published pole changing wide speed range induction motor drive for electric vehicles find, read and cite all the research you need on researchgate. An original method of changing the speed of squirrelcage induction motors has recently been developed which enables efficient and economic operation to be obtained at either of two chosen speeds, using a.
The area of multiphase variablespeed motor drives in general and. Pole changing speed control of 3 phase induction motor which is another type of the speed control from the stator side. In his paper, the stator was the same with that of polechanging induction motor, the rotor was built following the sandwich principle. Induction motors can be operated by the pole changing of variable speed drives. 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. Continuous polephase modulation allows an induction machine to change. N spite of increasing number of induction motors driven. The control of a continuously operated polechanging. The method has considerable generality, but is particularly applicable to speed ratios not very different from unity. How do just change in connections of stator winding. A dahlander motor also known as a pole changing motor, dual or two speed motor is a type of multispeed induction motor, in which the speed of the motor is varied by altering the number of poles. Pole changing method pole changing method is one of the main methods of the speed control of an induction motor. Vlado ostovic first proposed polechanging permanent magnet motor. Induction motor an induction or asynchronous motor is an ac electric motor in which the electric current in the rotor needed to produce torque and this torque is obtained by electromagnetic induction.
Pole changing of induction motor constant torque control. An induction motors rotor can be either wound type or squirrel cage type. 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. Suad ibrahim shahl 26 equivalent circuit model analysis example a 480v, 60 hz, 6pole, threephase, deltaconnected induction motor has the following parameters. Singlephase induction motors are usually twopole or fourpole, rated at 2 hp or less, while slower and larger motor can be manufactured for special purposes. The basic idea of an electric motor is to generate two magnetic fields. The 3phase set of currents, each of equal magnitude and with a phase. The speed of an induction motor is given as n 120fp 1s. In a conventional motor, the poles are in fixed positions. In this scheme, the number of pole pairs is changed by changing the field connection. With changes in the motor which do not cause an increase in current consumption.
For a two pole machine, for a p pole machine, 60 1 f e hz f m s n s m 120 2 n rpm p f rps p f e hz m s. In this post let us see what are the various methods to control the speed of induction motor. This method of controlling the speed by pole changing is used mainly for cage motor. In this video i describe about the speed control of induction motor by different type methods like, 1. In induction motor, field winding is wound on the stator while the armature winding is wound on the rotor. Synchronous speed, and therefore, motor speed can be changed by changing the number of poles. Modelling the salient pole motor is based on an equivalent circuit similar to that for the smooth rotor. Pole changing motor pdf pole changing motors are designed for drives with con stant torque characteristics and drives with quadrati cally rising torque because. Jan 09, 2017 speed control methods of induction motor. It is a 2pole motor because at any one time there is one north and one south magnetic pole. Kelly electrical and computer engineering michigan state university east lansing, mi 48824 28 february 2002 md lab. The control of a continuously operated polechanging induction machine j. For a four pole machine, 60 x 50 2 1500 rpm so the same size motor at 5. In such manner is attained one motor with two characteristics, but it is better than to offer to the.
The simple way of controlling machine and plant speeds economically. Jan 10, 2020 conversely, a 4 pole motor has low speed due to more number of poles. In his paper, the stator was the same with that of pole changing induction motor, the rotor was built following the sandwich principle, and some of the stator winding are used as the magnetizing coil. Pole changing motor pdf polechanging motors are designed for drives with con stant torque characteristics and drives with quadrati cally rising torque because. A 2 pole motor is not good for heavy power while, for heavy power, 4 pole motor is best. This method of controlling the speed by pole changing is used mainly for cage motor only because the cage rotor automatically develops a number of poles, which is equal to the poles of the stator winding. Permanent magnet motors capable of pole changing and three. Continuous operation of a pole changing induction machine. Polechanging motors 847 motor windings 850 multispeed contactors 853.
In electric drive applications that are based on highspeed induction motors ims with an extended speed range, stator winding polechanging is a. 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. Pdf modeling and analysis of a wide speed range induction. Pole changing can be used to achieve different speeds in induction machine by switching the configuration of the electrical stator. Pole changing wide speed range induction motor drive for. The control of a continuously operated polechanging induction. So we can easily change the speed of the induction motor by changing the number of poles. Nov 15, 2014 the induction motor will run at a slight less speed due to slip which is what gives the motor its torque. In an induction motor, the electric current in the rotor needed to produce torque is obtained via electromagnetic induction from the rotating magnetic field of the stator winding. It has been previously demonstrated that an induction machine drive with contactorless pole changing can be achieved by reversing current directions of certain stator coil groups.
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. Different methods of speed control of threephase asynchronous. 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. From the formula above, pole changing in induction machine can be done using a dahlander motor also known as a pole changing motor. Writtenpole motors differ from conventional motors in the way the magnetic field is developed. Difference between 2 pole motors and 4 pole motors.
Pole changing method of speed control is suitable for the cage rotor as they automatically develop the number of poles equal to the stator. It is shown that the primary winding of a 3phase induction motor, having p poles, say, may be reconnected to constitute a 3p pole winding of two or three symmetrical phase windings, the latter being little known and the former being a new type of pole changing connection with considerable practical possibilities. There, unlike in a starteralternator, continuous torque production is necessary. This induces an opposing current in the induction motor s rotor, in effect the motor s secondary winding, when the latter is shortcircuited or closed through an external impedance.
The stator magnetic field will rotate from a 1 to b1 to c1 and then back to a 1, 60 times each second. The pole changning motor is a very good demonstration equipment for student to understand the effect of polarity on speed of rotating machines. The machine selected for this system is a conventional lapwound squirrelcage rotor induction machine. Pole changing of induction motor for a given frequency, the synchronous speed is inversely proportional to the number of poles. This method of controlling the speed by pole changing is used. It is shown that the primary winding of a 3phase induction motor, having p poles, say, may be reconnected to constitute a 3ppole winding of two or three symmetrical phase windings, the latter. An integrated starteralternator system using induction. Various induction motor speed control methods advantages.
Pdf a new 46 polechanging double layer winding for three. Assume that when the alternating current reaches a. The rotor speed of an induction motor is given by the equation shown below. Magnetization analysis for polechanging permanent magnet.
So that speed of induction motor is inversely proportional to the number of poles in the induction motor. A 2 pole motor is more efficient on the flip side, a 4 poles motor is less efficient. Pole changing method of speed control is suitable for the cage rotor as they. The induction motor stators magnetic field is therefore changing or rotating relative to the rotor. Speed control of an induction motor there is a various method of speed control of an induction motor. Since the number of pole pairs can only be changed in steps like from 2 to 4, this scheme provides stepped. Pole changing method is one of the main methods of the speed control of an induction motor.
Permanent magnet motors capable of pole changing and. Here we have studied about the pole changing method of speed control of induction motor. Winding design, modeling, and control for pole phase modulation induction motors article pdf available in ieee transactions on magnetics 492. Pdf winding design, modeling, and control for polephase. Vlado ostovic first proposed pole changing permanent magnet motor. An original method of changing the speed of squirrelcage induction motors has recently been developed which enables efficient and economic operation to be obtained at either of two chosen speeds, using a single winding of standard type.
Modeling and analysis of a widespeedrange induction motor drive based on electronic pole changing. It is named after its inventor robert dahlander 1870. The rotor will constantly be turning to align its magnetic field with that of the stator field. This method of controlling the speed by pole changing, is used. Pole changing method speed control of induction motor. This paper compares power and torque capability of this with. Induction motor an induction or asynchronous motor is an ac electric motor in which the electric current in the rotor needed to produce torque and this torque is obtained by electromagnetic induction from the magnetic field of the stator winding. Jun 27, 2018 for the love of physics walter lewin may 16, 2011 duration. In pole changing method, the number of pole pairs is changed by changing the field connection. Ns can be varied by varying the factor on which it depends upon i. An induction motor also known as an asynchronous motor is a commonly used ac electric motor. Because a polechanging motor can vary the number of poles depending on speed, the motor lets evs operate with lower power consumption. Advantages of written pole motors include, low starting current.
The area of multiphase variablespeed motor drives in general and multiphase induction motor drives in particular has experienced a substantial growth since the beginning of this century. Magnetization analysis for polechanging permanent magnet motor. Request pdf induction motor with polechanging winding for variable supply frequency for induction drives that are operated at two speeds the approved. Speed control of three phase induction motor electrical4u. The motor may have fixed or variable torque depending on the stator winding. All about motors motor protection eaton wiring manual 0611 85 88 when does the overload relay fail to trip in good time although the motor is endangered. How to determine the pole number of an induction motor. Pole changing method is a speed control scheme of induction motor. Suad ibrahim shahl 26 equivalent circuit model analysis example a 480v, 60 hz, 6 pole, threephase, deltaconnected induction motor has the following parameters. An induction motor or asynchronous motor is an ac electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of. K nown in the industry as the pam motor, the tecowestinghouse pole amplitude modulation motor is the worlds most innovative ac induction. Find the synchronous speed of 4 pole induction motor which operates at 60 hz. Pole change induction motor for electric vehicles wiley online. So for varying the speed of the 3 phase induction motor we have to vary the ns.
Winding design, modeling, and control for polephase modulation induction motors article pdf available in ieee transactions on magnetics 492. Speed control of induction motor part 2 pole changing. This paper is an extension of work originally presented at. In a writtenpole motor, a magnetic layer is written in different places on the motors poles as the rotor turns. Speed of a dc shunt motor can be varied very easily with good. Generally, speed control using pole changing method is restricted to two steps. What is the electrical circuit diagram for pole changing. Mar 02, 2018 in this video i describe about the speed control of induction motor by different type methods like, 1. Pdf modeling and analysis of a widespeedrange induction. Control of a continuously operated polechanging induction machine. The speed of induction motor is changed from both stator and rotor side.
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