A wound rotor induction motor is also known as slip ring induction motor. Read here to know about the starting arrangement and the role played by the external resistances in obtaining better starting characteristics. What are the applications of a slipring induction motor. Construction of three phase induction motor electrical4u. Almost 80% of the mechanical power used by industries is provided by three phase induction. Slip ring motor fundamentals bright hub engineering. 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 slip ring induction motor is shown in the figure below. Pdf the use of squirrel cage motor for traction has revolutionised the motive power of a locomotive.
Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. The construction of slip ring induction motor is quite different compared to slip ring induction motor. M provides some advantages like provides high starting torque, low starting current and it improves the power factor. The rotor will constantly be turning to align its magnetic field with that of the stator field. 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. The construction of a stator is the same for both the squirrel cage and slip ring induction motor. The moflon slip rings are designed to endure harsh environmental conditions like acidic and salty media and extreme vibrations. Slip ring induction motor have big advantage of having high starting torque compared to squirrel cage motor. We can add external variable resistance to the rotor of this type of motor. Generally we all are know induction motor is most widely used motor in industrial. The construction of stator of the induction motor is almost the same as other motors. The slip ring induction motor could be used for industrial wires where variable speed and high starting torque are prime requirements. They are especially suitable for heavy load inertia applications. Design and analysis of drive system with slip ring induction motor for electric traction.
Difference between squirrel cage and slip ring motors. Pdf design and analysis of drive system with slip ring. Slip ring induction motors brush holder problems and solutions nathan schachter cimentec engineering ltd. The main difference in a slip ring induction motor is on the rotor construction and usage. The slip ring induction motor has two distinctly separate parts, one is the stator and other is the rotor. 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. Ysalient features y robust and nonflammable construction.
Formally, it is an electric transmission device that allows energy flow between two electrical rotating parts, such as in a motor. The slip ring motor has very little application in industries. 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. 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. 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. A slip ring motor is expensive, as are its controls, compared to a squirrel cage motor. This means that the state of the carbon brushes and the slip ring rotor can be monitored, and cleaning can take place. The shaft 11 and the slip ring structure 20 can rotate integrally. Diagnostics of rotor and stator problems in industrial. Slip in induction motor is the relative speed between the rotating magnetic flux and rotor expressed in terms of per unit synchronous speed. When a 3 phase supply is given to the stator winding it sets up a rotating magnetic field in space.
Tecowestinghouses wound rotor motors are designed with advanced features to ensure outstanding performance. Portland slip ring induction motorsbrush holder problems. The construction of slip ring induction motor is quite different compared to other induction motor. Slip ring motor conversion to vsd driven standard squirrel. The motor 10 is a motor for threephase alternating current and comprises a shaft 11 and a slip ring structure 20 constituting a rotor. The slip rings are mounted on the shaft with brushes resting on them. But the rotor construction differs with respect to the type of motor. 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. The main difference between slip ring induction motor is in rotor construction and usage. The function of the slip rings and the brushes is to provide a means of connecting external resistors in the rotor circuit. Slip ring induction motor working principle electrical. Induction motors generally will have low starting torque compared to dc series motor.
Alternatively, if one is overly slip ring motor conversion to. The construction is simple and robust and it is cheap as compared to slip ring induction motor. Starting of slip ring induction motor explained in an easy. The construction is complicated and the presence of brushes and slip ring makes the motor more costly. As there are no brushes and slip ring, these motors requires less maintenance. Carbon brush performance on slip rings mining electrical. Lpc series is a group of capsule slip rings of compact design with the outer diameter of 2254mm. 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. Slip ring motors are the motors of choice whenever high starting torque or low starting current are required. The material pairing used for the slipring contact system is normally bronzemetal graphite. 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. Also know about the qualities of slip ring induction motors. Squirrel cage induction motor is used in lathes, drilling machine, fan, blower printing machines etc.
Since then a lot of improvement has taken place on the design of these two types of induction motors. But how does external resistance aid in better starting characteristics. As it names wound rotor, the rotor is wound with a 3 phase windings. Kuhlmannwilsdorf in the mid1970s to improve the efficiency and reliability of high performance motor and generator commutator contacts ref. Slip rings induction motor provides some advantages like provides high starting torque, low starting current and it improves the power factor. This motor is rarely used only 10% industry uses slip ring induction motor. A slip ring assembly comprises of brush blocks, which are accurately harmonized and usually available as a set of a ring and a brush.
The slip ring rotor was developed after a decade or so. A squirrel cage motor is thus preferred to a slip ring motor. Mostafa elshahed objectives learn a brief history of the electrical power systems construction. High reliability slip ring design for wind turbines.
Three phase slip ring induction motor a wound rotor or slip ring motor has a 3phase winding, similar to the stator winding. Wound rotor induction motor the engineering projects. In the induction motors used in lift and hoists, you. 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. A slip ring in electrical engineering terms is a method of making an electrical connection through a rotating assembly. A slip ring induction motor can be started with external resistance added in its rotor circuit. What is the working principle of slip ring induction motor. A slip ring motor also requires a larger space for the motor and its. The construction of slip ring induction motor is same as other induction motors. Therefore slip ring induction motors are generally e. 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.
Slip ring motors can have many different ratings depending on the duty cycle for which they are specified. Rarely 5% 10% slip ring motors are used in industries because it has several disadvantages like it required. The 3phase set of currents, each of equal magnitude and with a phase. Induction motor seminar ppt, pdf report study mafia. 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. 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%. It is also called asynchronous motor because it does not run at a synchronous speed. Stemmanntechnik cable reels and slip ring assemblies. Lecture 6 three phase induction motors cairo university. It is mostly used in industrial drives because it is very reasonable and vigorous, economical and reliable. The brushes are connected to the variable resistor. I will tell you about the construction of wound rotor induction motor in the first section.
Induction motors have been ruling the industrial world for many decades. In normal conditions, the slip ring motor functions like a squirrel cage. We develop appropriate solution with characteristic lines that match precisely your specifications and demands for your application. Slipring induction motor connection and testing youtube. It is very commonly used in industries because it is very cheap, robust, efficient, and reliable. By putting resistance in series with the rotor windings, the starting current can be kept low while mainta. Chapter 3 induction motor and different speed control methods page no. 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. The brush holders are double boxtype brush holders. Mechanical design of slipring motor srsh 2 to 315 m. The basic idea of an electric motor is to generate two magnetic fields.
Already since 1927, we are a global manufacturer, supplier, and distributor of large slip ring motors up to 15000 kw and,8 kv. Construction of induction motor the three phase induction motor is a preferable type of motor. The slip ring rotor chamber has two modification openings. Free download induction motor seminar ppt, pdf report. Slip rings can also be called swivels, rotary joints, collectors, or commutators. 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. Three phase slip ring induction motor my tech info. Y provides smooth and stepless cutting of resistance in rotor circuit of the motor, reducing starting current and. The slip ring structure 20 includes slip rings 30u, 30v and 30w for three phases.
Woundrotor motors can be started with low inrush current, by inserting high resistance into the rotor circuit. The construction of the slipring induction motor is exactly similar to the construction of squirrel cage induction motor. Slip ring induction motor is made up from wound rotor and squirrel cage induction motor is made up from the squirrel cage rotor. The squirrel cage induction motor is the most popular type of ac motor. Slipring induction motor also known as rotor resistance start motor. Adjusting the resistance allows control of the speedtorque characteristic of the motor. Stator winding can be either star or delta connected depending upon the design. Slip ring induction motor fundamentals pnpntransistor. In the second section, i would be throwing light on the operation and working principle of wound rotor induction motor. 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 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.
1030 1514 326 1381 1354 474 1260 563 1161 1183 427 1417 1208 475 971 125 1098 1169 1492 793 703 748 724 633 629 1302 1171 58 166 26 1303 18 434 4 1512 613 1366 1387 72 1491 571 834 772 638 1309 749 79