You should also make a dc measurement of stator winding linetoline resistance. These motors are squirrel and slip ring type induction motors. Explain the unbalanced operation of the induction motor. The above block diagram shows the controlling of a three phase slip ring induction motor using programmable logic controller. Induction motor may be of single phase or three phase, or may be squirrel cage or slip ring type depending upon rotor structure. Depending on type of workload there are various type of starters for a slip ring induction motor. Search wegthreephaseinductionmotorstlinesquirrelcage. What are the type of starter used for slip ring induction motor.
This work has developed a steadystate and dynamic mathematical model of three phase slipring induction motors with external impedance. Oct 30, 2015 induction motor speed so, the im will always run at a speed lower than the synchronous speed the difference between the motor speed and the synchronous speed is called the slip where nslip slip speed nsync speed of the magnetic field nm mechanical shaft speed of the motor slip sync mn n n. Slip ring induction motor application slip ring induction motor provides high starting torque. If a set of three phase current is added to these three coils, rotating field is created in air gap which rotates with suitable speed with frequency of the applied current. Be specially designed for energy saving purpose which is totally enclosed and fancooled type. Transient analysis of threephase wound rotor slipring. Rev for threephase motor connection power and control diagrams. The pictorial representation of three phase induction motor with written pole technology is shown in the figure. Squirrel cage motor almost 90% of induction motors are squirrel cage motors. Different types of starters for induction motor nptel. Slip torque characteristics of an induction motor my. A single phase induction motor has two types of rotor. Three phase slip ring induction motor my tech info.
Starting and speed control of 3phase slip ring induction. Induction motor types based on the construction of the rotor, induction motors are broadly classified in two categories. Starting and speed control of 3phase slip ring induction motor using plc ravichandra adda. Good performance, such as high safety, energy saving, compact design, low noise, little vibration, high torque big breakaway torque, reliable operation, stable running and convenient maintenance. Depending upon the type of rotor construction used the three phase induction motor are. Low and high voltage three phase induction motors slip ring rotor. Starters limit the starting current in an induction motor which goes 56 times of full load current as slip remains 1. Thus the speed of 3 phase slip ring induction motor was controlled by rotor resistance control method. Theory and analysis of three phase induction motor using. Induction motor basics, single phase and three phase. Allowing 250 w for the copper loss in the shortcircuiting gear and w for mechanical losses, find the resistance per phase of the 3phase rotor winding.
Squirrel cage wound rotor with slip rings the rotating magnetic field. As discussed earlier, a slip ring induction motor is an asynchronous motor, as the rotor never runs in synchronous speed with the stator poles. Low and high voltage three phase induction motors slip ring rotor fixed brushholderm line date. If the 3 phase slip ring induction motor is started as a normal motor with the slip rings shorted, due to low starting torque of slip ring motor, the motor will draw high current i. Threephase induction motor consists of a stator and a rotor, and there is no electrical connection between these two. Search wegthreephaseinductionmotorsmasterline50019089brochureenglish. And determine the full load regulation of a three phase synchronous generator by synchronous impedance method. The three phase wound rotor slipring induction motor is modeled using parks transformation technique. Slip ring induction motors brush holder problems and solutions nathan schachter. The analysis is then used to study the characteristics of threephase induction motors under unbalanced rotor impedances.
Usually slip ring ims are preferred because of its advantages over squirrel cage ims. The emf induces in the rotor because of the relative motion, or we can say the slip speed of the motor. Torque slip characteristic of an induction motor low. Portland slip ring induction motorsbrush holder problems. Torque slip characteristic of an induction motor the torque slip characteristic is represented by a rectangular hyperbola. Differential equations are solved using computer simulation. Three phase ac induction motors are widely used in industrial and commercial applications. Types, construction and principle of operation, 3 phase induction motor, general. This motor benefits from the experience of one of the largest manufacturers in the world, using stateoftheart technology in automation, specially selected materials and rigorous quality cont rol. Slip power recovery system in three phase slip ring induction motor 1jagendra singh, 2swati rani, 3rohini. What external resistance per phase must be added in the rotor circuit so that the motor now runs ate a slip of 17. Search wegthreephaseinductionmotorsmasterline50019089. For the immediate value of the slip, the graph changes from one form to the other.
One singlephase wattmeter plus miscellaneous apparatus as needed. This is similar to a transformer, whose secondary is rotating and shortcircuited. Search weglowandhighvoltagethreephaseslipringrotorvertical11734748manualenglish. Discuss the procedure of noload and blocked rotor test with test setup arrangement. Regardless of how or at what stage you supply your design data, you can be. This laboratory book in electrical engineering laboratory is intended. The maximum torque developed in an induction motor is called the pull out torque or the breakdown torque. Starter using additional resistance in rotor circuit, for wound rotor slipring. Generally, induction motor provides low starting torque as compared to d. Though some information was used during the start up phase. As we know, the slip speed is the difference between the synchronous and rotor speed of the induction motor. 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.
Export data and price of motor slip ring under hs code. Transient modeling of induction motors prove to be more difficult both in the definition of suitable forms of equations and in the application of appropriate numerical methods needed for the solution of same okoro 2003. Jinpat mediumsized capsule slip ring lpc series products are installed in the parking lot gates according to customers requirements, integrated sensor signals, can open bus, 0. A woundrotor motor, also known as slip ringrotor motor, is a type of induction motor where the rotor windings are connected through slip rings to external. The method is also verified experimentally for a 7. In normal conditions, the slip ring motor functions like a squirrel cage motor. Electrical study app objective questions on induction motor 2. The rotor bars in squirrelcage induction motorsare not straight, but have some skew to reducenoise and harmonics. This type of rotor has a 3 phase, doublelayer, distributed winding consisting of coils used in alternators. A wide variety of three phase slip ring motor options are available to you, such as ccc, ce. Assignment three phase induction motor iiteeeestudents. The three phase induction motor is the most widely used electrical motor. Objective questions on induction motor 2 electrical.
The principles are those that you learned in your study of alternating current. The rotor of the slip ring induction motor is also cylindrical or constructed of. This work has developed a steadystate and dynamic mathematical model of three phase slip ring induction motors with external impedance. Slip ring induction motor fundamentals pnpntransistor. Nov 27, 2019 the three phase induction motor is the most widely used electrical motor. Slip power recovery system in three phase slip ring. The stator construction is the same in both motors. The squirrel cage motor is mostly started by stardelta stater and hence the stator of squirrel cage motor are delta connected. These are of two types, squirrel cage and slip ring motors. Stator winding can be either star or delta connected depending upon the design.
Slip ring induction motor are used where high starting torque is required i. The slip is defined as the ratio of difference of synchronous speed and actual rotor. Derivation of the expression for the gross torque developed as a function of slip speed of induction motor. Slip ring rotor or wound rotor or phase wound rotor. Search wegthreephaseinductionmotorstlinesquirrelcagerotor12364818manualenglish. The speed of the motor comes to zero, when the slip reaches to 1. Three phase induction motors used in explosive atmospheres w60 line squirrel cage rotor horizontal date. Slip rings, media rotary joints, mechatronic components.
No name of the apparatus type range quantity 1 ammeter mi 010a 1 2 voltmeter mi 0600v 1 3 rotor resistance starter 1. An843, speed control of 3phase induction motor using pic18 mcus. Why we need to start induction motor using a starter or with one of starting methods. Standard design ic 411 3phase slip ring induction motors in the mebsgr series. Three phase slip ring motor wholesale, motor suppliers alibaba. Three phase induction motor explain the equivalent circuit and phasor diagram of three phase induction motor. 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. The slip ring motors in our mebsgr series that are described in the following text are in the ic 411 cooling class, known as surfacecooled or ribbedcooled. The winding wound on the stator of three phase induction motor is also. The rotor resistance per phase of the winding is 0. The rotor winding terminals are connected to three slip rings which turn with the rotor. The construction of a stator is the same for both the squirrel cage and slip ring induction motor. The single phase stator winding produces a magnetic field that pulsates in strength in a sinusoidal manner. The torque slip curve for an induction motor gives us the information about the variation of torque with the slip.
In a version of the ac induction motor referred to as a wound rotor motor, slip rings are. Apr 18, 20 starting and speed control of 3 phase slip ring induction motor using plc ravichandra adda. So, the rotor current is directly proportional to the induced emf. Three phase induction motor consists of a stator and a rotor, and there is no electrical connection between these two. Characteristics of threephase induction motors under. The rotor core is made up of steel laminations which have slots to. Per phase equivalent circuit motor slip r 1 and r 2. List out the basic steps of drawing the circle diagram with any one example. Ppt induction motor powerpoint presentation free to.
The terminal box consists of three sets of six terminals of three stator windings. Menzel low voltage slip ring motors, series mebsgr germanenglish pdf. Thus, it passes through the point of maximum torque when r 2 sx 20. Torque slip characteristics of three phase induction motor. Perform no load and block rotor test on 3 phase induction motor. Hence slip ring motors are used where one or more of the above requirements are to be met. C series motors but this disadvantages of the induction motor can be overcome by slip ring induction motor. To control the speed control of 3 phase slip ring induction motor by rotor resistance control.
An induction motor im is an ac machine which finds its extensive use in the field of industrial and commercial areas. Three phase slip ring motor wholesale, motor suppliers. The slip ring three phase induction motor are started by inserting resistances so, the stator winding can be connected either in star or delta. What are slip rings and why do some motors use them. Induction motors an induction motor has two magnetically coupled circuits. Construction of three phase induction motor electrical4u. These motors are selfstarting and use no capacitor, start winding, centrifugal switch or other starting device. Hence the stable operating region of the motor lies for the slip values, s0, and that corresponds to maximum torque. Record all nameplate information for the induction motor. The rotor of the slip ring induction motor is also cylindrical or constructed of lamination. Split phase motors are designed to use inductance, capacitance, or resistance to develop a starting torque. Starting and speed control of 3phase slipring induction.
Types, construction and principle of operation, 3 phase induction motor, general phasor diagram, equivalent circuit, power and torque relations, condition for maximum torque, circle diagram. Almost 80% of the mechanical power used by industries is provided by three phase induction motors because of its simple and rugged construction, low cost, good operating characteristics, the absence of commutator and good speed regulation. This type of rotor is provided with a 3phase, doublelayer, distributed winding consisting of coils used in alternators. So, this motor is used in applications like lifts, pumps, mills where we require high starting torque. It is very important that this brace be reinstalled exactly as it was originally, before the motor is moved from storage or any time when the motor is being transported. Three coils are placed on the stator of squirrelcage three phase induction motor which they have phase difference with each other 120 degrees. The main advantage of a slip ring induction motor is that its speed can be controlled easily. Torqueslip speed characteristics of induction motor im threephase induction motor mechanical engineering notes edurev notes for mechanical engineering is made by best teachers who have written some of the best books of mechanical engineering. A 3 phase induction motor can be used for different applications with various speed and load requirements. Threephase induction motor protection systems and its. If the 3phase slip ring induction motor is started as a normal motor with the slip rings shorted, due to low starting torque of slip ring motor, the motor will draw high current i.
A wound rotor or slip ring motor has a 3phase winding, similar to the stator winding. Torque slip characteristics of induction motor electrical4u. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. By putting resistance in series with the rotor windings, the starting current can be kept low while mainta. Based on type of phase supply three phase induction motor self starting in nature single phase induction motor not self starting other squirrel cage induction motor slip ring induction motor 11. Learn more about the construction and operation of a slip ring induction motor. It consists of plc board which has input and output ports, contactors which are used for either to close or to openthe terminals and one three phase slip ring induction motor. To determine for an induction motor on block rotor test, relationship. Torqueslip speed characteristics of induction motor im. Split phase induction motors one type of induction motor, which incorporates a starting device, is called a split phase induction motor.
One single phase wattmeter plus miscellaneous apparatus as needed. Jul 12, 2017 3 phase slip ring induction motor sudipto mondal. View detailed export data, price, monthly trends, major exporting countries, major ports of motor slip ring under hs code 8501. Lecture notes electrical machine ii bee 1401 page 1. An 8 pole, 50 hz slip ring induction motor runs at a slip of 2. 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 slip ring induction motor could be used for industrial wires where variable speed and high starting torque are prime requirements. Venturetec mechatronics gmbh is a specialist in the development and manufacturing of slip rings and rotary joints, as well as mechatronic components, subsystems and complete systems. Venturetec mechatronics is a recognised partner of leading hightech companies in the fields of health care, industrial automation, aviation and marine drives, with locations in germany and commercial agencies. About 78% of these are ac motor, 1% are electrical contacts and contact materials. What is the working principle of slip ring induction motor. Feb 25, 2017 depending on type of workload there are various type of starters for a slip ring induction motor. Low and high voltage three phase induction motors slipring rotor date. What are the type of starter used for slip ring induction.
These stator and rotors are made up of highmagnetic core materials with less hysteresis and eddy current losses. Poptronics197801 electrical engineering electronics scribd. Slip rings are devices that can transmit power, electrical signals. These motors are squirrel and slipring type induction motors. The slip rings brushes allow external resistors to be connected in series with the winding. The slip ring induction motors usually have a phasewound rotor. Construction of three phase induction motor magic marks duration.