Each rotor bar is represented as an independent circuit connected to an end ring that has a constant resistance and inductance. Optimizing the efficiency of three phase squirrel cage induction motors scims plays a. What is a squirrel cage motor and how does it work. Working principle of 3 phase squirrel cage induction motor. Two digital multimeters and fluke power quality meter with banana cables from the. The reason for the name squirrel cage is because of the type of rotor used in these motors. In electrical equipment the anchors winding would be induced by the magnetic field, although the rotor takes this part in threephase induction motors. Three phase squirrel cage induction motors can also be used as generators. A threephase, squirrel cage induction motor is fed by a voltagesource inverter. The picture of a tiny squirrel cage motor, illustrating the squirrel cage rotor, is shown in figure 3a. Squirrel cage rotor three phase induction motor the rotor core is cylindrical and slotted on its periphery. Almost 80% of the mechanical power used by industries is provided by three phase induction motors because of its simple and rugged construction, low cost, good operating characteristics, the absence of commutator and good speed regulation.
Parts of an induction motor three phase induction motor. Designing of three phase squirrel cage induction motor for. Y2 series 3phase induction motors are characterized with. Squirrel cage induction motor requires significantly less maintenance as it does not contain brushes, commutators, slip rings. In this work a conventional three phase squirrelcage type induction motor with specifications 10 hp, 415v, stardelta connected and 4 poles is chosen for comparison with our motor, which is.
Set up and connections threephase induction motor noload and fullload operation threephase induction motor operation characteristics threephase induction motor direction of rotation p rocedure high voltages. Jul 25, 2019 what is squirrel cage induction motor. Background the simplest and most widelyused rotor for induction motors is the socalled squirrel cage rotor, from which the squirrel cage induction motor gets its name. This method is normally limited to smaller cage induction motors, because starting current can be as high as eight times the full load current of the motor. Y2 series 3 phase induction motors are characterized with. A successful salesman for general electrics motor division once remarked to one of your instructors that, when asked by a customer how a motor. Also appreciate the rugged construction of squirrel cage rotor and know the spectacular reasons for the skewed arrangements of the rotor conductors. The design of y2 series induction motor absorbed the advanced technology of electric motors around the world. The stator has windings that produce a magnetic field, and. The most common type of rotor used in a three phase induction motor is a squirrel cage rotor. Induction motor has the same physical stator as a synchronous machine with an alternate rotor development.
The stator winding is assumed to be yconnected with the access to the phase terminals. There is no electrical connection between these bars. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. It is called a squirrel cage motor because the rotor inside of it known as a squirrel cage rotor looks like a squirrel cage. Advantages of three phase squirrel cage induction motor. This method is normally limited to smaller cage induction motors, because starting current can be as high as. The rotor will constantly be turning to align its magnetic field with that of the stator field.
The general construction of the slots in the rotor is such that the rotor bars. Be careful it can hurt to tangle with a three phase motor. Watch this video and learn basics of squirrel cage induction motor. Three phase slip ring induction motor my tech info. This rotor is made up from parallel aluminum or copper bars. The first commutatorfree single phase ac induction motor was invented by hungarian. The squirrel cage rotor consists of a laminated iron core which is slotted lengthwise around its periphery. Menzel squirrel cage motors are available in all standard motor cooling and protection types for lowvoltage from 75 kw as well as medium and high voltage up to 25,000 kw.
In a threephase induction motor, the number of poles in the rotor winding is always. Construction of three phase induction motor electrical4u. Basically, it is the construction of rotor which makes squirrel cage induction motor different from wound type induction motor. Three phase squirrel cage induction motors are widely used in industrial drives because they are rugged, reliable and economical. The three phase induction motor is the most widely used electrical motor. Three phase squirrel cage induction motors are widely used as industrial drives because they are selfstarting, reliable and economical. The torque of the induction motor depends on the rotor resistance.
Since here we are talking about maintenance of induction motor, and it is of two types. These motors are tested to strict quality control for routine and type tests at every stage of production and are ideally suitable for various industrial applications. Know about the most popular and almost unbreakable construction of squirrel cage induction motor. Rotor has a winding the same as stator and the end of each phase is connected to a slip ring. When a 3 phase supply is given to the stator winding it sets up a rotating magnetic field in space. Be careful it can hurt to tangle with a threephase motor. A threephase, squirrelcage induction motor is fed by a voltagesource inverter. Scope regulation eu 42014 covers single speed, three phase, 50 hz and 60 hz induction motors with. The three phase squirrel cage induction motors are classified into 6 different standard types based on their electrical characteristics. To obtain the load performance characteristics of a three phase squirrel cage induction motor. Single phase induction motors are used extensively for smaller loads, such as household appliances like fans.
The mesh in the air gap may or may not be remeshed at each time step. The rotor consists of uninsulated copper or aluminium bars called rotor conductors. They have speeds ranging from 900 to 3600 rpm in 60 hz and from 750 to 3000 rpm in 50 hz applications. The threephase induction motor is the extensively used for various kinds of industrial drives. Three phase squire cage induction motor, fully enclosed. Squirrel cage induction motor an overview sciencedirect topics. An induction motor s rotor can be either wound type or squirrel cage type. In simple words, the type of 3 phase induction motor which uses a squirrel cage rotor is called squirrel cage induction motor. Induction motor might be worked as either motors or generator. The stator of slip ring induction motor is very much the same as that of the squirrel cage induction motor, but the construction of its rotor is very much different.
It is usually designed for fixedspeed operation, larger ratings having such features as deep rotor bars to limit direct on line dol starting currents. Induction motor basics, single phase and three phase. But at the starting of the induction motor, starting current is very large which may damage motor windings. Pdf in the european union, the average load factor of electric motors in both industrial and tertiary sectors is estimated to be less than 60% find. The maximum torque of a squirrel cage induction motor is also called pullout torque because of the way the motor reacts to an overload. This article will focus on what needs to be specified for squirrel cage induction motors, which involves phase, speed, torque, and. Threephase induction motor squirrel cage rotor customer. Know about the different winding slots, lamination of the stator and its construction. To learn more, feel free to visit our article on the types of ac motors. A squirrel cage rotor core is made by stacking thin steel laminations to form a cylinder.
In the squirrel cage induction motor the rotor slots are usually given. This article presents an understanding of what squirrel cage induction motors are and. This motor should be mounted on the motor bench, wherein the motor shaft may be coupled to the dynamometer for taking the measurements. The threestator windings develop a rotating magnetic flux rotating at synchronous speed. Squirrel cage induction motor the engineering projects.
Y2 series three phase induction motor i asynchronous motor y2 series three phase asynchronous motor is a kind of totally enclosed fancooled tefc squirrel cage induction motor. Compared to squirrel cage rotors, wound rotor motors are. Threephase squirrelcage induction motors are widely used as industrial drives. Construction of squirrel cage induction motor explained. A 3 phase squirrel cage induction motor is a type of three phase induction motor which functions based on the principle of electromagnetism. What are the specific applications of squirrel cage and. These bars are shorted at each end with shorting rings. Normally, we use the motors in industrial drives because they are rugged, reliable and economical. For higher ratings refer to high efficiency large motors with dcca. Our article all about induction motors explains the specifications for all types of induction motors and is a good place to see all the different induction motor characteristics.
The starting torque of a 3phase squirrel cage induction motor is. What is the difference between a squirrel cage motor and a. Three phase induction motors an electric motor is a device which converts electrical energy into. After the maximum torque point which is three to four times the fullload torque, the decrease in rotor p. Menzel squirrel cage motors are available in all standard motor cooling and protection types for lowvoltage from 75 kw as. Three phase squirrel cage induction motor with inverter section model 0100hz.
The three phase induction motor is the extensively used for various kinds of industrial drives. The motor efficiency class and nominal motor efficiency must be stated on the motor nameplate and given in product documentation and motor catalogues. The main difference between slip ring and squirrel cage induction motor is the rotor construction. Parida department of electrical engineering national institute of technology, silchar. A hollow rotor would have a much less efficient performance. Threephase squirrelcage induction motors are widely used as industrial drives because they are selfstarting, reliable and economical. Squirrel cage induction motor an overview sciencedirect. Set up and connections threephase induction motor noload and fullload operation threephase induction motor operation characteristics threephase induction motor direction of rotation p rocedure high voltages are present in this laboratory. Chemical industry severe duty motors are built to ieee standard 841.
Menzel squirrel cage induction motors are manufactured for various industries and industrial applications of all kinds. Pdf modelling of the threephase induction motor using. Three phase induction motor squirrel cage rotor customer. The new iec 60034301 defines worldwide the following efficiency classes of singlespeed threephase, cage induction motors in the 0,12 kw power range.
The most commonly used induction motor type is the three phase motor ranging from 1 to 250 hp. Design of a three phase squirrel cage induction motor for. This paper describes a generalized simulation model of the three phase induction motor using the simulink software package of matlab. Threephase squirrelcage induction motors are widely used in industrial drives because they are rugged, reliable and economical. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. The 3phase set of currents, each of equal magnitude and with a phase. L direct on line starte it is simple and cheap starter for a 3phase induction motor. In squirrel cage induction motor, there is a 3 phase winding on the stator slots. The slip ring induction motor could be used for industrial wires where variable speed and high starting torque are prime requirements.
Oct 09, 2016 in simple words, the type of 3 phase induction motor which uses a squirrel cage rotor is called squirrel cage induction motor. This paper describes a generalized simulation model of the threephase induction motor using the simulink software package of matlab. An induction motor can therefore be made without electrical connections to the rotor. When the 3 phase supply is provided to the stator, a magnetic field is produced which rotates the rotor and motor starts. Squirrel cage induction motors menzel elektromotoren. The basic idea of an electric motor is to generate two magnetic fields. Now let us discuss in detail, the most common form of induction motor, the squirrel cage induction motor. These windings are either star connected or in delta connected. In a squirrel cage induction motor, the rotor has conductive bars embedded in slots in the laminations, running the length of the rotor.
So the main idea behind motor maintenance is to prevent breakdown rather than repairs them. The three phase squirrelcage induction machine is the most used motor in industry applications. Kanpur, india design of a three phase squirrel cage induction motor for electric propulsion system ravi prakash,mohammad junaidakhtar, r. Stator winding can be either star or delta connected depending upon the design. Third international conference on advances in control and optimization of dynamical systems march 15, 2014. Dec 10, 2015 watch this video and learn basics of squirrel cage induction motor. Because the squirrel cage winding is not large enough to dissipate the heat of continuous operation, large synchronous machines often have protective relays to detect when the machine has fallen out of synchronization with the supply voltage. Singlephase induction motors are used extensively for smaller loads, such as household appliances like fans. An induction motors rotor can be either wound type or squirrelcage type. The two typed of rotor constructions which are used for induction motors are squirrel cage rotor and slip ring wound rotor. The rotor of a squirrel cage induction motor is shor. Pdf novel multiflux level, threephase, squirrelcage induction. This simplest form of ac induction motor or asynchronous motor is the basic, universal workhorse of industry.
In this work a conventional three phase squirrel cage type induction motor with specifications 10 hp, 415v, stardelta connected and 4 poles is chosen for comparison with our motor, which is designed for good efficiency. The induction motor is started by itself that we know. Ac induction motors are also the most common motors used in main powered home appliances. The principle of working of squirrel cage and slip ring induction motor is based on faradays law of electromagnetic induction. In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them.
Parameters identification of the threephase squirrelcage induction. Foot mounted b3 construction 3 phase squirrel cage induction motors suitable for v. We saw the construction of the squirrel cage induction motor. An induction motor or asynchronous motor is an ac electric motor in which the electric current. Y2 series three phase induction motor i asynchronous motor y2 series three phase asynchronous motor is a kind of totally enclosed fancooled tefc squirrelcage induction motor. The squirrel cage rotor is so called because its construction is reminiscent of the rotating exercise wheel found in some pet cages. High power asynchronous squirrel cage compact motor. Most of the motors used in industry are induction motors.
Windings are such placed that they are electrically and mechanically 120 o apart from in space. Squirrel cage wound rotor with slip rings the rotating magnetic field the basic idea of an electric motor is to generate two magnetic fields. This rotating magnetic field has a speed which is known as the synchronous speed this rotating magnetic field induces the voltage in rotor bars and hence shortcircuit currents start flowing in the rotor bars. Explain starting methods of 3 phase induction motor. A 3 phase ac induction motor photoed by hordu motor. Threephase squirrel cage induction motors for centrifugal pumps for agricultural applications by bureau of indian standards.
In a three phase induction motor, the number of poles in the rotor winding is always. To measure the inrush current when the motor starts. L direct on line starte it is simple and cheap starter for a 3 phase induction motor. Parida department of electrical engineering national institute of technology, silchar,assam, india email. Load tests on a three phase induction motor and measurement of the inrush current objectives.
120 1077 802 448 477 1562 654 419 145 994 290 111 243 509 232 206 1075 251 1020 1244 612 638 681 312 1126 571 1654 6 1225 1071 1288 974 1224 291 1086 1402 349 313 257