A methodology is presented to compute the temperature field of a double squirrelcage and the core of an induction motor. Some of the most common types of squirrel cage motor use three phases, meaning the input current is three identical ac frequencies, split by 120 degrees of phase. Control of motor characteristics by squirrelcage rotor design. In deep bar double cage rotor bars are there in two layers. A 3 phase squirrel cage induction motor is a type of three phase induction motor which functions based on the principle of electromagnetism. The advantages of squirrel cage and wound rotor induction motors are combined in the double cage induction motor. Horizontal squirrel cage mediumvoltage induction motor.
In this chapter, we shall focus our attention on the construction, working and characteristics of commonly used singlephase motors. Using variable voltage variable frequency vvvf drive. A 3 phase induction motor has two types based on the rotor construction, named as. Recall that leakage reactance is the reactance due to the rotor flux lines that do not also couple with the stator windings. Double squirrel cage motor is one of the three phase induction motors which are the most commonly used induction motors and most of the induction motor applications that require high starting torque and high efficiency operation, single phase synchronous.
The rotor slot and rotor conductor has modified shape or modified peculiar shape can be draw or can be develop. Construction of squirrel cage induction motor explained. How are high starting torques obtained in a squirrel cage. Designing of three phase squirrel cage induction motor for. High during starting and low at normal operating speed. For higher torque requirements a deep bar cage motor is used.
Motors of this type employ squirrel cage having relatively low resistance and reactance. This rotor is a cylinder of steel laminations, with highly. In this article, we will learn about squirrel cage and slip ring induction motors. However, should the motor require service, this manual includes a section that assists the. Defining the model geometry of the three phase induction double squirrel cage asynchronous motor in fem 3d. An induction motors rotor can be either wound type or squirrelcage type. The basic idea of an electric motor is to generate two magnetic fields. Advantage of double cage rotor over single cage rotor. How are squirrel cage induction motors constructed.
Keeping the vf ratio constant, when frequency is reduced then that results in constant slipfrequency at running. The double cage motor is so develop that it overcomes the above difficulties and given good starting torque with good efficiency for that purpose. Slip ring induction motor is made up from wound rotor and squirrel cage induction motor is made up from the squirrel cage rotor. Squirrel cage motors are the most commonly used induction motors, but the main drawback in them is their poor starting torque due to low rotor. In this small post we will discuss about the double cage induction motor in brief. Oct 09, 2016 a 3 phase induction motor has two types based on the rotor construction, named as. Also appreciate the rugged construction of squirrel cage rotor and know. Squirrel cage induction motors from 380 v to,800 v.
Double cage induction motor introduction diy electrical. Its torquespeed and currentspeed characteristics are such that, on starting, a torque of typically twice fullload torque is produced but a large current typically, six to eight times fullload current is drawn from the supply. Hence, this squirrel cage single bar single cage rotor is not being able to apply against high load. After releasing the blockage, the by now heated motor is started up again. May 18, 2018 please have a look at the below figures of squirrel cage induction and wound rotor slip ring induction motor.
The slots are not made parallel to each other but are bit skewed skewing is not shown in the figure of squirrel cadge rotor beside as the skewing prevents. The construction of the rotor is rugged and simple. Novel method of improving squirrel cage induction motor. The principal advantages of the squirrelcage induction motor are its simplicity of design and robust construction. According to the labelled notation a represents stator b rotor c bearing shields d fan e venti. Three phase induction motors used in explosive atmospheres w60 line squirrel cage rotor horizontal date. Modeling of three dimensional magnetic field in threephase induction motor with double squirrel cage.
For a squirrelcage motor, the rotor as represented in figure 2 is constituted by a system of bars in copper or aluminum, which are coaxial to the rotation axis and directly diecast in the slots made along the external periphery of the ferromagnetic. Laminations from typical squirrelcage induction motor rotors, showing the cross. Iec squirrelcage motors type series 1le, 1pc, 1la, 1lg, 1ll, 1lp, 1ma, 1mj, 1pp, 1pq frame sizes 63 to 450 power range 0. Double squirrel cage motor we have already discussed that the rotor which is of squirrel cage type has two end rings, which are permanently shorted with the rotor conductors. Double cage rotor a rotor design, which though more expensive gives still better starting, and running performances than the deepbar design, is the doublecage rotor. Standard types of squirrel cage motors are as explained below. Emergency motor switchon happens occasionally while operating a double squirrelcage motor at full supply voltage with the rotor. In this rotor, each of end rings electrically connecting the associated ends of the conductor bars received in the slots of the rotor core comprises a first ring portion disposed in contact with the associated end face of the rotor core, and a second ring portion disposed on or coupled to the first ring portion through a member of a. In this chapter, we shall focus our attention on the construction, working and.
This work is introducing the designing of new three phase squirrel cage induction motor with an objective of getting good efficiency. The starting torque and the starting periods is also large. The rotor of the motor consists the cylindrical laminated core having semiclosed circular slots and short circuit at each end by copper or aluminium ring, called short circuiting ring. Modeling of three dimensional magnetic field in threephase. Squirrel cage rotor and slip ring rotor squirrel cage vs wound rotor duration. Former is cheaper and broadly used as it requires less maintenance than later one. Menzel squirrel cage motors are available in all standard motor cooling and protection types for lowvoltage from 75 kw as well as. It is called a squirrel cage motor because the rotor inside of it known as a squirrel cage rotor looks like.
Know about the different winding slots, lamination of the stator and its construction. The phase induction motor with three double cage has the following rated data. Dont worry, difference between squirrel cage and slip ring type induction motor is tabulated after the figure. Generally in induction motor related operations, squirrel cage induction motors are widely used. The motor which employing squirrel cage type rotor is known as the squirrel cage motor. A methodology is presented to compute the temperature field of a double squirrel cage and the core of an induction motor. Difference between squirrel cage and slip ring induction motor. Squirrel cage motor for sale, three phase induction motor. Threephase motors are selfstarting, meaning the only necessary input is a starting voltage, and makes these motors essentially plugandplay. Squirrel cage induction motor the engineering projects. Sep 15, 2017 double cage induction motor is used for cage rotor to increase rotor resistance so higher starting torque can achieve by this method.
Know about the construction of double squirrel cage motor with a graphical comparison with single cage. As the name suggests, the rotor of this motor has two squirrelcage windings located one above the other as shown in fig. Pdf modeling of three dimensional magnetic field in three. Squirrel cage induction motor an overview sciencedirect. These bars are shorted at each end with shorting rings. It is called a squirrel cage motor because the rotor inside of it known as a squirrel cage rotor looks like a squirrel cage.
The squirrelcage winding in this design consists of two layers of bars shortcircuited by end rings. This motor should be mounted on the motor bench, wherein the motor shaft may be coupled to the dynamometer for taking the measurements. Control of motorcharacteristics by squirrelcage rotordesign. The figure itself depicts many difference between the two types of motors. The stator winding is assumed to be yconnected with the access to the phase terminals. The advantages of squirrelcage and wound rotor induction motors are combined in the double cage induction motor. Dec 10, 2015 watch this video and learn basics of squirrel cage induction motor. Starting of squirrel cage induction motors485 an induction motor can be regarded as a transformer with a small air gap in the magnetic circuit. Pdf the model of doublecage induction motor for the. A squirrel cage rotor for an induction motor is disclosed. Control of motorcharacteristics by squirrelcage rotordesign the reactance x2 in an induction motor equivalent circuit represents the referred form of the rotors leakage reactance. A motor rating of 10 horse power, 415 volts with 1440 rpm and 4pole is selected for design problem and an.
When the double cage motor is running at normal speed, frequency of the rotor emf is so low that the reactance of both cages is negligible. The motor rotor shape is a cylinder mounted on a shaft. The rotor of the squirrel cage three phase induction motor is cylindrical in shape and have slots on its periphery. A squirrel cage induction motor therefore draws a very high starting. The torque speed characteristics of double squirrel cage motor for both the cages are shown in the figure below. In a slip ring induction motor, the rotor resistance is a. This arrangement is used for obtaining high starting torque at a low value of starting current. Squirrel cage induction motor and wound rotor induction motor. Hp squirrelcage induction motor which you have to parameterize.
The rotor of the motor consists the cylindrical laminated core having semiclosed circular slots and short circuit at each. What is a squirrel cage motor and how does it work. Please have a look at the below figures of squirrel cage induction and wound rotor slip ring induction motor. Pdf the model of doublecage induction motor for the analysis of. These motors are having the difference in rotor construction. Construction of deep bar double cage induction motor. The procedure employs a threedimensional model of the motor heating. The squirrel cage induction motor was designed for an extended service life under very demanding conditions.
Double squirrel cage induction motor your electrical guide. Internally it contains longitudinal conductive bars usually made of aluminium or copper set into grooves and connected at both ends by shorting rings forming a cage like shape. The 3phase set of currents, each of equal magnitude and with a phase. Watch this video and learn basics of squirrel cage induction motor. The construction of stator of the induction motor is almost the same as other motors. What is the difference between a squirrel cage motor and a. Internally it contains longitudinal conductive bars usually made of aluminium or copper set into grooves and connected at both ends by shorting rings forming a cagelike shape. Looking for dayton 12hp 115v double inlet forward curve blower with motor 1xjy1. In a squirrel cage induction motor, the rotor has conductive bars embedded in slots in the laminations, running the length of the rotor.
The upper slot conductors from the outer cage and the lower slot conductors form the inner cage. The rotor will constantly be turning to align its magnetic field with that of the stator field. But the rotor construction differs with respect to the type of motor. Dec 26, 2015 in this small post we will discuss about the double cage induction motor in brief. Current versus speed characteristics, double cage rotor, induction motor. We should go for deep bar double cage induction motor to get higher starting torque. Induction motors, squirrel cage rotors, application engineering, mining industry. For a double cage rotor, the same rule as above applies. As the name indicates, the double cage induction motors have two cages in the rotor and they have the advantages of both squirrel cage induction motors and wound rotor induction motors. Search wegthreephaseinductionmotorstlinesquirrelcage. Know about the most popular and almost unbreakable construction of squirrel cage induction motor. Double cage induction motor is used for cage rotor to increase rotor resistance so higher starting torque can achieve by this method. Three phase induction motor construction your electrical guide.
The name is derived from the similarity between this ringsandbars winding and a squirrel cage. Threephase squirrelcage induction motors are widely used as industrial drives because they are. Us4309635a squirrelcage rotor having end rings of double. The squirrelcage winding in this design consists of. The model of doublecage induction motor for the analysis of. A double squirrel cage induction motor consists of a rotor which has two independent cages one above the other in the same slot. Double cage rotor of an induction motor a double cage induction motor is that type of motor in which a double cage or two rotor windings or cages are used. Pdf evaluation of the detectability of broken rotor bars.
Pedra, joaquim 2015 squirrelcage induction motor parameter estimation using a variable frequency test. Evaluation of the detectability of broken rotor bars for double squirrel cage rotor induction motors conference paper pdf available october 2010 with 3,334 reads how we measure reads. Mar 09, 2018 in this article, we will learn about squirrel cage and slip ring induction motors. Jul 25, 2019 a 3 phase squirrel cage induction motor is a type of three phase induction motor which functions based on the principle of electromagnetism. The two cages being connected in parallel, the combined resistance is lower. As the name indicates, the double cage induction motors have two cages in the rotor and they have the advantages of. Menzel squirrel cage induction motors are manufactured for various industries and industrial applications of all kinds. Firstly, i am going to tell you about the structure of squirrel cage induction motor. An induction motor can therefore be made without electrical connections to the rotor. Motor torque, load torque and selection of motors contents 2. Double cage rotor of an induction motor 6nq8vq6w61nw. A double squirrel cage rotor is shown in the figure. Also appreciate the rugged construction of squirrel cage rotor and know the spectacular reasons for the skewed arrangements of the rotor conductors. The slip ring construction is used for large size motors.
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