In the induction motors used in lift and hoists, you. Slip ring motor 3 with their solid construction and special design in cast iron or steel akh slip ring motors still have a big resonance in numerous industry sectors. Squirrel cage induction motor is used in lathes, drilling machine, fan, blower printing machines etc. Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. Already since 1927, we are a global manufacturer, supplier, and distributor of large slip ring motors up to 15000 kw and,8 kv. The slip ring rotor was developed after a decade or so.
The 3phase set of currents, each of equal magnitude and with a phase. As there are no brushes and slip ring, these motors requires less maintenance. The squirrel cage induction motor is the most popular type of ac motor. Three phase slip ring induction motor a wound rotor or slip ring motor has a 3phase winding, similar to the stator winding.
As it names wound rotor, the rotor is wound with a 3 phase windings. The slip ring induction motor has two distinctly separate parts, one is the stator and other is the rotor. Slip rings can also be called swivels, rotary joints, collectors, or commutators. Woundrotor motors can be started with low inrush current, by inserting high resistance into the rotor circuit. Induction motors have been ruling the industrial world for many decades. Alternatively, if one is overly slip ring motor conversion to. A slip ring motor is expensive, as are its controls, compared to a squirrel cage motor. The construction of slip ring induction motor is quite different compared to slip ring induction motor. In the second section, i would be throwing light on the operation and working principle of wound rotor induction motor. Stemmanntechnik cable reels and slip ring assemblies for opencast mining devices and mobile construction machines brochure english download pdf for more information please visit our website. Slip ring induction motor fundamentals pnpntransistor. Slip ring induction motor is made up from wound rotor and squirrel cage induction motor is made up from the squirrel cage rotor. It is also called asynchronous motor because it does not run at a synchronous speed. Ysalient features y robust and nonflammable construction.
The construction of slip ring induction motor is quite different compared to other induction motor. The slip ring rotor chamber of the ic 411 slip ring induction motor is separated by what is known as a labyrinth seal, which prevents contamination from coal dust. They are especially suitable for heavy load inertia applications. This motor is rarely used only 10% industry uses slip ring induction motor. Slip ring motors can have many different ratings depending on the duty cycle for which they are specified. Difference between squirrel cage and slip ring motors. High reliability slip ring design for wind turbines. The slip ring motor has very little application in industries. The motor 10 is a motor for threephase alternating current and comprises a shaft 11 and a slip ring structure 20 constituting a rotor. A slip ring induction motor can be started with external resistance added in its rotor circuit. If the standard squirrel cage motor is selected purely on nominal power, for example a 37 kw to replace a 37 kw slip ring motor, then the starting torque may not be sufficient.
Slip ring induction motors brush holder problems and solutions nathan schachter cimentec engineering ltd. Almost 80% of the mechanical power used by industries is provided by three phase induction. It is very commonly used in industries because it is very cheap, robust, efficient, and reliable. Construction, working, advantages, disadvantages, characteristics and applications single phase unexcited synchronous motor the characteristic of single phase unexcited synchronous motor in which excitation does not necessary is given below. Since then a lot of improvement has taken place on the design of these two types of induction motors. A wound rotor induction motor is also known as slip ring induction motor. Lpc series is a group of capsule slip rings of compact design with the outer diameter of 2254mm. The construction is simple and robust and it is cheap as compared to slip ring induction motor. Adopted the advanced military surface processing technique and goldgold contact, such capsule slip rings are perfectly suitable for application where weak signal transmission is dominated advantages. When a 3 phase supply is given to the stator winding it sets up a rotating magnetic field in space. Some changes in the stator may be encountered when a slip ring motor is used in a cascaded system, as the supply for the slave motor is controlled by the. It also requires meticulous and periodic maintenance of the brushes, brush gear, slip rings, external rotor resistances etc. Chapter 3 induction motor and different speed control methods page no. But the rotor construction differs with respect to the type of motor.
What are the applications of a slipring induction motor. A slip ring in electrical engineering terms is a method of making an electrical connection through a rotating assembly. We develop appropriate solution with characteristic lines that match precisely your specifications and demands for your application. Slip ring motor fundamentals bright hub engineering. Tecowestinghouses wound rotor motors are designed with advanced features to ensure outstanding performance. By putting resistance in series with the rotor windings, the starting current can be kept low while mainta.
M provides some advantages like provides high starting torque, low starting current and it improves the power factor. The construction is complicated and the presence of brushes and slip ring makes the motor more costly. Slip rings induction motor provides some advantages like provides high starting torque, low starting current and it improves the power factor. For load sharing to take place automatically, the motor speed should drop considerably as the load increases and this is ensured by using a motor having a high fullload slip, say for example 10%. Formally, it is an electric transmission device that allows energy flow between two electrical rotating parts, such as in a motor. The construction of a stator is the same for both the squirrel cage and slip ring induction motor. Induction motor seminar ppt, pdf report study mafia. A squirrel cage motor is thus preferred to a slip ring motor.
Starting of slip ring induction motor explained in an easy. The main difference in a slip ring induction motor is on the rotor construction and usage. Slipring induction motor connection and testing youtube. Also know about the qualities of slip ring induction motors. The rotor circuit resistance has significant impact on starting torque, the speed at which the breakdown torque occurs, and the slip during the normal running operation. The slip rings are mounted on the shaft with brushes resting on them. The shaft 11 and the slip ring structure 20 can rotate integrally. Slip ring induction motor working principle electrical. Construction of three phase induction motor electrical4u. Read here to know about the starting arrangement and the role played by the external resistances in obtaining better starting characteristics. Slip ring induction motor have big advantage of having high starting torque compared to squirrel cage motor. Mechanical design of slipring motor srsh 2 to 315 m. The brush holders are double boxtype brush holders. We can add external variable resistance to the rotor of this type of motor.
The value of slip in induction motor is can never be zero. 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. Slipring induction motor also known as rotor resistance start motor. I will tell you about the construction of wound rotor induction motor in the first section. Carbon brush performance on slip rings mining electrical. Induction motors generally will have low starting torque compared to dc series motor. The main difference between slip ring induction motor is in rotor construction and usage. Type of construction im 1001 im b3 type of construction im 3011 im v1 motor shaft heigh nos of poles drive end non drive end bearing lubrication lubrication. The moflon slip rings are designed to endure harsh environmental conditions like acidic and salty media and extreme vibrations. Portland slip ring induction motorsbrush holder problems. 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. Therefore slip ring induction motors are generally e. The slip ring structure 20 includes slip rings 30u, 30v and 30w for three phases.
The slip ring rotor chamber has two modification openings. Some changes in the stator may be encountered when a slip ring motor is used in a cascaded system, as the supply for the slave motor is controlled by the supply. The rotor will constantly be turning to align its magnetic field with that of the stator field. The construction of the slipring induction motor is exactly similar to the construction of squirrel cage induction motor. The slip ring induction motor could be used for industrial wires where variable speed and high starting torque are prime requirements. Adjusting the resistance allows control of the speedtorque characteristic of the motor.
Mostafa elshahed objectives learn a brief history of the electrical power systems construction. A slip ring assembly comprises of brush blocks, which are accurately harmonized and usually available as a set of a ring and a brush. Slip ring motor conversion to vsd driven standard squirrel. But how does external resistance aid in better starting characteristics. Telecommunication engineering, southwest jiaotong university, china, 2005 thesis submitted for the degree of masters of engineering science in school of electrical and electronic engineering the university of adelaide, australia august 2010. Pdf design and analysis of drive system with slip ring. The construction of slip ring induction motor is same as other induction motors. Some changes in the stator may be encountered when a slip ring motor is used in a cascaded system, as the supply for the slave motor is controlled by the supply from the rotor of the other slip ring motor with external resistance mounted on its rotor. Pdf the use of squirrel cage motor for traction has revolutionised the motive power of a locomotive.
Diagnostics of rotor and stator problems in industrial induction motors by fang duan b. 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. Kuhlmannwilsdorf in the mid1970s to improve the efficiency and reliability of high performance motor and generator commutator contacts ref. The construction of stator of the induction motor is almost the same as other motors. Rarely 5% 10% slip ring motors are used in industries because it has several disadvantages like it required. Slip in induction motor is the relative speed between the rotating magnetic flux and rotor expressed in terms of per unit synchronous speed. Three phase slip ring induction motor my tech info. The basic idea of an electric motor is to generate two magnetic fields. Slip ring motors are the motors of choice whenever high starting torque or low starting current are required. In normal conditions, the slip ring motor functions like a squirrel cage. Stemmanntechnik cable reels and slip ring assemblies. The material pairing used for the slipring contact system is normally bronzemetal graphite.
What is the working principle of slip ring induction motor. Free download induction motor seminar ppt, pdf report. It is mostly used in industrial drives because it is very reasonable and vigorous, economical and reliable. Design and analysis of drive system with slip ring induction motor for electric traction. Wound rotor induction motor the engineering projects.
Lecture 6 three phase induction motors cairo university. Stator winding can be either star or delta connected depending upon the design. A woundrotor motor slip ring motor is a type of induction motor where the rotor windings are connected through slip rings to external resistances. The brushes are connected to the variable resistor. Generally we all are know induction motor is most widely used motor in industrial. Construction of induction motor the three phase induction motor is a preferable type of motor. A slip ring motor also requires a larger space for the motor and its. The function of the slip rings and the brushes is to provide a means of connecting external resistors in the rotor circuit. This means that the state of the carbon brushes and the slip ring rotor can be monitored, and cleaning can take place.
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