A wound rotor motor uses three slip rings typically made of copper. Lamination is necessary since a voltage is induced along the axial length of the steel as well as in the stator conductors. Slip ring induction motor working principle electrical. We can react very quickly due to a comprehensive stock of slip ring motors in a power range up to 15000 kw. Slip ring induction motor are used where high starting torque is required i. 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. However, the rotor construction of the slip ring motor is quite interesting. Slipring induction motor connection and testing youtube. Slip ring or phase wound induction motor squirrel cage induction motor construction is complicated due to presence of slip ring and brushes construction is very simple. Depending on the individual customers requirements, the slip rings are built into steel or aluminium housings. Slip rings are made of high quality phosphor bronze and are of molded construction. A wound rotor motor uses three slip rings typically made of copper or a copper alloy mounted to but insulated from the motor shaft. Ppt induction motor powerpoint presentation free to.
Abb slipring modular motors abb high voltage induction. It is important to understand the design and construction of slip ring assemblies in order to properly specify and evaluate their reliability and maintenance requirements. Higher maintenance of brushes and slip rings compared to squirrel cage motor. A slip ring in electrical engineering terms is a method of making an electrical connection through a rotating assembly. Pdf design and analysis of drive system with slip ring. Diagnostics of rotor and stator problems in industrial induction motors by fang duan b. If we go through any sort of machinery, whether it is manual or. The induction motor are of two types based on the construction of rotor. A wound rotor induction motor is also known as slip ring induction motor. Wound rotor induction motors ac motors electronics. Slip ring induction motor or wound induction motor or phase wound induction motor. Design and analysis of drive system with slip ring induction motor for electric traction. The following table outlines that difference in each construction, working principles and services needs. The slip ring induction motor working in the induction principle.
Starting of slip ring induction motor explained in an easy. What is the difference between a slip ring and a squirrel. Construction of three phase induction motor electrical4u. Pdf the use of squirrel cage motor for traction has revolutionised the motive power of a locomotive. Wound rotor induction motors chapter ac motors pdf version. High reliability slip ring design for wind turbines. We develop appropriate solution with characteristic lines that match precisely your specifications and demands for your application. The three ends of three phase windings are permanently connected to these.
The spring driven cable reels from moog construed for harsh environments in the construction machinery and crane industry application. The construction of stator of the induction motor is almost the same as other motors. There are two types of induction motors, one with wound type rotor, also called slip ring motor and another one with squirrelcage rotor. In the induction motors used in lift and hoists, you will see a type of rotor called a slip ring rotor, whereas in most of the other applications you. The construction of slip ring induction motor is quite different compared to slip ring induction motor.
Slip ring induction motor have big advantage of having high starting torque compared to squirrel cage motor. The slip rings are used to in conjunction with the brushes to deliver a current to the rotor. Slip ring induction motor construction, working and its speed. But how does external resistance aid in better starting characteristics. This, combined with the fullybraced and vacuumimpregnated windings, ensure they are extremely efficient and reliable. A slip ring is an electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure. Product lines include slip rings, fiber optic rotary joints, motors, position sensors, actuators, fluid rotary. Fiber brush technology provides long life and operation. However, on a slip ring motor, the secondary losses divide in proportion to the inherent rotor winding resistance and the connecting external resistance. Induction motors have been ruling the industrial world for many decades. Slip ring motor fundamentals brighthub engineering.
Rotor as the name suggests it is a rotating part of an electrical machine, in which current is induced by transformer action from rotating magnetic field. The rotor of the slip ring induction motor is also cylindrical or constructed of lamination. The absence of slip ring and brushes make the construction of squirrel cage three phase induction motor very. The slip ring motor has very little application in industries. Electric motors have several advantages whenever we compare with normal engines which include the following. A slip ring structure for facilitating an adjusting operation after assembling is provided. The main difference in a slip ring induction motor is on the rotor construction and usage. By far the most commonly used ac motor is the induction motor. Slip ring motor manufacturer menzel provides shortterm availability and adaptation, applicationspecific requirements and worldwide logistics. They are designed for applications with high rotational speeds and high mechanical swing loads.
The rotor winding terminals are connected to three slip rings which turn with the rotor. 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. Slip ring induction motors brush holder problems and solutions nathan schachter. Difference between slip ring and squirrel cage induction motor. A high reliability, maintenancefree slip ring is possible with. According to the labelled notation a represents stator b rotor c bearing shields d fan e ventilation grill and f. Induction motors generally will have low starting torque compared to dc series 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. Depending upon the type of rotor construction used the three phase induction motor are classified as. The construction of slip ring induction motor is quite different compared to other induction. In special application, like remote controlled robots, moog designed motor driven cable reels with contact less. The construction of the slipring induction motor is exactly similar to the construction of squirrel. Squirrel cage rotor wound type rotor or slip ring type rotor squirrel cage rotor in this type. Materials is very important for slip ring performance in the production,one factors should be taken into account when design and make slip rings, we know, slip ring is belongs the application of electrical contact which is fall into two groups, one is rotating electric contact, such as electrical slip ring, slip ring and electric rotating joint. 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.
Brushes are used to take connection from these slip rings at starting high external resistances are usually included to improve starting torque and reduce starting current. The slip ring motor has an external resistance circuit for controlling the speed of. Instead of bars, in this motor three windings are used. Slip ring induction motor is made up from wound rotor and squirrel cage induction motor is made up from the squirrel cage rotor. The working principles and stator construction of the slip ring induction motor are exactly the same as that of the squirrel cage motor. It is a type of motor where its external circuit is connected using some. Motor this kind of slip ring is used in motors that are used in mining. Slip ring assembly systems the cast slip ring assemblies with carbon brush system are very robust and guarantee high durability. So we simply surrender transmission of electric pulses through a turning structure, for this purpose a slip ring is. Learn a brief history of the electrical power systems construction. If connected to rotor winding the starting torque of motor is equal to the rated torque. It is very commonly used in industries because it is very cheap, robust, efficient, and reliable. M provides some advantages like provides high starting torque, low starting current and it improves the power factor.
In the second section, i would be throwing light on the operation and working principle of wound rotor induction motor. A woundrotor motor, also known as slip ringrotor motor, is a type of induction motor where the. We can add external variable resistance to the rotor of this type of motor. The set of rings are a complete electrical circuit within the motor.
Electric motor construction of induction motors britannica. A squirrel cage motor is thus preferred to a slip ring motor. Slip rings are made of high quality phosphorbronze and are of moulded construction. But the rotor construction differs with respect to the type of motor. Slipring motors are still used in many branches of industry. A slip ring motor also requires a larger space for the motor and its controls. Squirrel cage wound rotor with slip rings the rotating magnetic field the basic idea of an electric motor is to generate two magnetic fields. Electric motor electric motor construction of induction motors. When motor attains normal speed, three brushes are short circuited. This final thesis will mostly be dedicated to induction motors but also to synchronous permanent magnet and reluctance motors. Formally, it is an electric transmission device that allows energy flow between two electrical rotating parts, such as in a motor. A slip ring structure 20 comprises slip rings 30u, 30v and 30w respectively provided to be rotatable about a common axis. Induction motor works on the principle of electromagnetic induction.
The construction of a stator is the same for both the squirrel cage and slip ring induction motor. Also know about the qualities of slip ring induction motors. This article encompasses the working principle of slip ring induction motor, construction, speed control, resistance calculation and its applications. In the slip ring type,the rotor consists of three phase winding similar to that of the stator winding. In the induction motors used in lift and hoists, you will see a type of rotor called a slip ring. Mechanical design of slipring motor s rsh 2 to 315 m 1 housing 5 rotor 9 fan cowl 2 end shield 6 bearings 10 slip ring contact system.
A wound rotor induction motor has a stator like a squirrel cage induction motor, but a rotor with insulated windings brought out via slip rings and brushes. This construction of the rotor is aimed at reducing the phase difference. The phasewound motor generally used in slip ring motors, has a 3phases and doublelayered winding. Read here to know about the starting arrangement and the role played by the external resistances in obtaining better starting characteristics. The stator frame consists of laminations of silicon steel, usually with a thickness of about 0. Therefore slip ring induction motors are generally e. The anatomy and operation of these motors will be explored, as well as the specific characteristics that make them so vital to applications where other, more.
Slip ring induction motor fundamentals pnpntransistor. 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. I will tell you about the construction of wound rotor induction motor in the first section. The laminations are insulated from each other usually by a varnish layer. What are slip rings and why do some motors use them.
In this article, we shall discuss this motor s construction, working, speed control, advantages, disadvantages, and applications. The construction of a stator for both of the kinds of three phase induction motors is identifcal, and is discussed briefly below. Each slip ring is connected to one of the three phases of rotor windings. Slip rings from moog assembled at the end of ship winches or motor driven cable reels in harbor cranes. Types of construction im b3, im b35, im b5 and derived types to iecen 600347. Portland slip ring induction motorsbrush holder problems. Different construction is done to keeping in view to advance its advantages and applications. A slip ring induction motor can be started with external resistance added in its rotor circuit. Slips are supposed to improve mechanical performance, simplify system operation and damageprone wires dangling from movable joints. What are the applications of a slipring induction motor. The slip ring structure 20 comprises bus bars 40u, 40v and 40w connected to the slip rings 30u, 30v and 30w of the respective phases and extending in the axial direction.
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