The figure itself depicts many difference between the two types of motors. Stator winding is similar to that of a synchronous motor. But the rotor construction differs with respect to the type of motor. Most of single phase induction motors use squirrel cage rotor as it has a remarkably simple and robust construction enabling it to operate in the most adverse circumstances.
In this article, we will learn about squirrel cage and slip ring induction motors. Pdf squirrel cage induction motor design and the effect of. Squirrel cage induction motors have poor starting torque and high starting currents. These motors are suitable for all general applications where an open machine is not applicable due to severe environments such as excessive dirt, dust andor moisture. Almost 70% of the industrial motors and drives comes under these category. Dont worry, difference between squirrel cage and slip ring type induction motor is tabulated after the figure. Starting of squirrel cage induction motors485 an induction motor can be regarded as a transformer with a small air gap in the magnetic circuit. Difference between squirrel cage and slip ring induction motor. A squirrel cage rotor or a wound rotor can be used.
Methods for varying speed in squirrel cage induction motors. The rotor of an induction motor can be a squirrel cage rotor or wound. Now let us discuss in detail, the most common form of induction motor, the squirrel cage induction motor. Supplementary specification to iec 600341 low voltage three. These are of two types, squirrel cage and slip ring motors. Designing of three phase squirrel cage induction motor for. The ruggedness and simplicity of the squirrelcage induction motor usually makes it the first choice for a driver. In a squirrel cage induction motor, the rotor has conductive bars embedded in slots in the laminations, running the length of the rotor. Advantages and disadvantages of squirrel cage induction motor. This can be done by simply adjusting the shape of the bars in the rotor. Kalsi group product categories squirrel cage induction motors. The conversion process is electromagnetic induction.
Stator poles rotate at the synchronous speed ns when fed with a three phase supply. These induction motors require special attention during its design process boldeo and nasar 2002. Almost 95% of the induction motors used is of squirrel cage type. At hordu 19 years induction motor manufacturer, we have a range of three phase induction motors that vary in design, technology and production capacity. For duty cycles other than s1 please refer to teco.
All other regions in the motor are considered nonconducting. Fig 1 energy consumption chart of different motors ii. However, it is possible to consider a squirrel cage three phase induction motor as an ordinary electrical circuit with va. 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 the stator winding. A typical 3phase squirrelcage motor has six connection leads in the electrical connection box for the three coils. New rotor fault indicators for squirrel cage induction motors.
Energy efficient induction motors internet archive. The slip ring motor has very little application in industries. The squirrel cage induction motors are 90% used in various industrial, domestic and commercial applications. The reason for the name squirrel cage is because of the type of rotor used in these motors.
Squirrel cage induction motors are simpler in structure than dc motors and are most commonly used in the vsd industry. Squireel cage induction motors are widely used in industries. In simple words, the type of 3 phase induction motor which uses a squirrel cage rotor is called squirrel cage induction motor. Mostafa elshahed objectives learn a brief history of the electrical power systems construction. Design of a three phase squirrel cage induction motor for. The rotor needs to be rotated at a speed near to the synchronous speed during starting. An induction motor s rotor can be either wound type or squirrelcage type. Squirrel cage induction motors are very prevalent in industry, in sizes from below 1 kilowatt 1. Pdf methods for varying speed in squirrel cage induction motors. They are particularly suited for applications where the motor must maintain a constant speed, be selfstarting, or there is a desire for low maintenance. List and describe the more commonly used equipment in. The main disadvantage of squirrel cage induction motor is poor speed control and low starting torque. Information guide for general purpose industrial ac small.
What is the difference between a squirrel cage motor and a. Flexible 5 ratings correspondence 220380415v50hz,220440v60hz is standard. An anisotropic homogeneous representation for both squirrelcage rotor and stator windings is used. Three phase squirrel cage induction motors ie1 motors maa baa series ie2 motors maq baq series. A typical 3phase squirrel cage motor has six connection leads in the electrical connection box for the three coils. Specifications and standards ie1 maa baa series technical characteristics technical data dimensions ie2 maq baq series technical characteristics technical data dimensions contacts 03 07 07 08 12 15 15 16 18 20.
But increasing the rotor resistance for improving starting torque is not advisory as it will reduce the efficiency of the motor due to more copper loss. Normally, we use the motors in industrial drives because they are rugged, reliable and economical. An induction motor can be regarded as a transformer with a small air gap in the magnetic circuit. They are based on the sidebands of phase current upper harmonics, and they are well suited for. Design of a threephase squirrelcage induction motor based on efficiency maximization using fem software mucet2008paper no here. If done so, the rotor poles get magnetically coupled with the rotating stator poles, and thus the rotor starts rotating at the synchronous speed. They are built to cope with the toughest conditions, and reliably ensure the durable availability of your industrial facilities. Our article all about induction motors contains a discussion of the principal laws behind all induction motors and gives an understanding of how motion is created from magnetism. Singlephase induction motors are used extensively for smaller loads, such as household appliances like fans. Pdf improving squirrel cage induction motor efficiency. Notice and disclaimer the information in this publication was considered technically sound by a consensus among persons engaged in its development at the time it was approved. Otherwise, the guide gives no information as to how the curves are constructed. Please have a look at the below figures of squirrel cage induction and wound rotor slip ring induction motor.
Differentiate between the various types of generating electric power stations. Menzel 3 phase squirrel cage induction motors are robust, efficient and durable. There is a wide variety of design options available depending upon the motor size and application. As you can see, the 3 phase squirrel cage induction motor could achieve the electromechanical energy conversion simple and straight forward. What is a squirrel cage motor and how does it work. Construction of squirrel cage induction motor explained. Since 1927, users around the world have been able to rely on highquality 3 phase squirrel cage induction motors made by menzel.
Pdf three phase squirrel cage induction motor, conctruction. Closedform analysis of squirrelcage induction motors with. Supply voltage stock motors are designed for operation as below. Squirrel cage induction motor an overview sciencedirect. Variable voltage variable frequency vf control theory an induction motor compared to a dc motor has some major advantages such as absence of brushes, commutator segments, rugged construction, being cheap, lesser maintenance requirements and smaller. Squirrel cage induction motor the engineering projects.
And in the previous article on types of electrical motors, we have classified induction motors based on the type of rotor used. Yahya shakweh, in power electronics handbook fourth edition, 2018. Supplementary specification to iec 600341 low voltage. Working principle of 3 phase squirrel cage induction motor. Nov 03, 2019 an induction motor also known as an asynchronous motor is a commonly used ac electric motor. The squirrel cage induction motor is the most commonly used motor in industry. It is very commonly used in industries because it is very cheap, robust, efficient, and reliable. A squirrel cage induction motor therefore draws a very high starting current, as noted in section 1. Cage rotor induction motor im is widely accepted as the most potential candidate for electric propulsion owing, to their reliability, robustness, less maintenance. However, with variable frequency drives, these disadvantages can be overcome. Energy efficient induction motors three phase squirrel cage. Search wegthreephaseinductionmotorstlinesquirrelcage. Design of a three phase squirrel cage induction motor for electric. Squirrel cage induction motors are commonly used in many industrial applications.
Using thermal limit curves to define thermal models of. A squirrel cage motor comprises a stator and a rotor, the latter having a pair of end rings and conductor bars interconnecting the end rings, the bars and rings being supported on the rotor core. The three phase squirrel cage induction motors are classified into 6 different standard types based on their electrical characteristics. Squirrelcage rotor options for ac induction motors request pdf. These motors are tested to strict quality control for routine and type tests at every stage of production and are ideally suitable for various. Squirrel cage wound rotor with slip rings the rotating magnetic field the basic idea of an electric motor is to generate two magnetic fields. 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. Defining the thermal models the basic equations found in thermal protection modeling are derived in the annex. Threephase ac induction motors are widely used in industrial and commercial applications. Squirrel cage rotor almost 90 per cent of induction motors are squirrel cage type, because this type of rotor has the simplest and most rugged construction imaginable and is almost indestructible.
The rotor of the motor can be braked to stop at a predetermined. When a 3 phase supply is given to the stator winding it sets up a rotating magnetic field in space. What are the advantages of a squirrelcage induction motor. Lecture 6 three phase induction motors cairo university. Improving squirrel cage induction motor efficiency. At least one end ring is provided with at least two insulating gaps to divide that end ring into at least two separate portions. Starting torque is directly proportional to the rotor resistance. An induction motor s rotor can be either wound type or squirrelcage. Thermal limit curves for squirrel cage induction machines 2.
The theory of three phase induction squirrel cage motors. The ruggedness and simplicity of the squirrel cage induction motor usually makes it the first choice for a driver. These bars are shorted at each end with shorting rings. Teco totally enclosed fan cooled squirrel cage induction motors are designed, manufactured and tested to meet or exceed the latest nema, ieee, csa and other international standards. The squirrel cage induction motor was designed for an extended service life under very demanding conditions. Pdf studying and improving of squirrel cage induction motor scim efficiency is a continuous area of interest not only among the researchers but also. 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 resistance. The squirrel cage induction motor is the most popular type of ac motor. May 18, 2018 please have a look at the below figures of squirrel cage induction and wound rotor slip ring induction motor. Pdf design of a threephase squirrelcage induction motor.
Particularly, the squirrel cage type is simplicity, robustness and low cost, which has always made it very goodlooking and therefore, captured the leading place in industrial sector. These motors fill most generalpurpose, constantspeed drive requirements. Induction motor basics, single phase and three phase. Information guide for general purpose industrial ac small and. List and describe the more commonly used equipment in an electric substation. 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. How are squirrel cage induction motors constructed. In squirrel cage induction motors, rotor windings wound in squirrel cage. Jul 25, 2019 application of squirrel cage induction motor. Difference between synchronous motor and induction motor. These motors are having the difference in rotor construction. Torquespeed characteristics of three phase squirrel cage. An induction motor also known as an asynchronous motor is a commonly used ac electric motor.
Horizontal squirrel cage mediumvoltage induction motor. Today, an induction motor can be run at any speed by using an inverter. Slip ring induction motor is made up from wound rotor and squirrel cage induction motor is made up from the squirrel cage rotor. Threephase squirrelcage induction motors are widely used as industrial drives because they are selfstarting, reliable and economical. It converts electrical energy into mechanical energy and it is used to provide motion. The construction of stator of the induction motor is almost the same as other motors. However, we can conclude that each curve is a plot of a specific limiting temperature. There is no electrical connection between these bars. Low and high voltage three phase induction motors m line squirrel cage rotor horizontal date. It is low cost and requires low maintenance in comparison with other motor types. If someone works with ac 3phase motors, then it is important to know how to connect these motors in star and delta connection, and how to detect an electrical problem. In essence, squirrel cage motors work no differently than most other induction motors and only differ in the specific interaction between rotor and stator. Threephase induction motors induction motor is simply an electric transformer whose.
Squirrelcage rotor options for ac induction motors. Introduction cage rotor induction motor im is widely accepted as the most potential candidate for electric propulsion owing, to their reliability, robustness, less maintenance and ability to work in hostile environments. However, it suffers from the disadvantage of a low starting torque. However, should the motor require service, this manual includes a section that assists the.
A squirrel cage induction motor therefore draws a very high starting. Various applications toshiba motor is used for various applications. An induction motor can therefore be made without electrical connections to the rotor. These motors are selfstarting and use no capacitor, start winding, centrifugal switch or other starting device. Squirrelcage rotor almost 90 per cent of induction motors are squirrelcage type, because this type of rotor has the simplest and most rugged construction imaginable and is almost indestructible. Mar 09, 2018 in this article, we will learn about squirrel cage and slip ring induction motors. These motors are very robust in construction and very cheap. Rarely 5% 10% slip ring motors are used in industries because it has several disadvantages like it required. Squirrel cage induction motors are used a lot in industry as they are. Frame size 180m and above, 380660v50hz is standard. They are simple, rugged, and selfstarting, and maintain a reasonably constant speed from light load to full load, set by the frequency of the power supply and the number of poles of the. Basically, it is the construction of rotor which makes squirrel cage induction motor different from wound type induction motor.
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