Since this seems to be a matter of using an existing slip ring motor, from start not designed for vfd, the most important concern in this is the insulation of the windings, not which drive principle that is preferred. Speeds can be adjusted in the case of slip ring wound rotor induction motor by inserting an resistance. Explain the principle and operation of ac series motor. Y provides smooth and stepless cutting of resistance in rotor circuit of the motor, reducing starting current and. In the case of three phase ac alternating current operation, the most widely used motor is a 3 phase induction motor, as this type of motor does not require an additional starting device. What are the type of starter used for slip ring induction. Oct 04, 2017 3 phase motor with resistance type starter. Starting andcontrol of slipring 5 electrical engineering book. Contrast this with an induction motor, which must slip in order to produce torque.
Slip ring induction motor construction, working, speedcontrol. Free download induction motor seminar ppt, pdf report. Explain with neat diagram the construction and working of single phase im. A squirrel cage motor is thus preferred to a slipring motor. A squirrel cage motor is thus preferred to a slip ring motor. By putting resistance in series with the rotor windings, the starting current can be kept low while maintaining good starting torque. 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 operating principle and internal structure of the slip. A wound rotor, has a 3phase winding similar to the stator winding. This means that the state of the carbon brushes and the slip ring rotor can be monitored, and cleaning can take place. An electrical motor is an electromechanical device which converts electrical energy into mechanical energy. Dc motors although ac motors are used in most of the cases, dc motors have many applications and used for multipurpose applications.
Explain any two types of single phase induction motors. The speed at which the rotating magnetic field revolves is called the synchronous speed ns. Nov 27, 2019 the three phase induction motor is the most widely used electrical motor. Dc motor principle a machine that converts dc power into mechanical energy is known as dc motor. What are the type of starter used for slip ring induction motor. Feb 25, 2017 depending on type of workload there are various type of starters for a slip ring induction motor. Each slip ring motor has a resistance value that when connected to the rotor will result in a starting torque of 100%. Already since 1927, we are a global manufacturer, supplier, and distributor of large slip ring motors up to 15000 kw and,8 kv. They are especially suitable for heavy load inertia applications. Proposed circuit diagram of the traction drive system using wrim. When a threephase power supply is given to the stator of a threephase motor. Similarly figure shows the disassembled view of a slip ring motor a stator b. Working principle of slip ring induction motor the working principle of slip ring i. The slip ring induction motor working in the induction principle.
They set technical standards in terms of size, performance, economy and reliability. A slip ring motor is expensive, as are its controls, compared to a squirrel cage motor. The slip ring motor has very little application in industries. Working principle of 3 phase squirrel cage induction motor. Slip power losses are more during speed control due to use of variable resistance rheostat in previous methods. The fluxes passes from stator to rotor winding through induction principle. The stator is the same as is used with a standard squirrel cage motor. Construction of three phase induction motor electrical4u. A slip ring motor is normally not designed for the extreme high dudt values stressing the winding insulation at vfd drive fast. 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.
Smooth starting of slip ring induction motors article pdf available in ieee transactions on energy conversion 124. The rotor winding terminals are connected to three slip rings which turn with the rotor. Slip ring induction motor working principle electrical. Advantages and disadvantages of slip ring induction motor. The slip ring or wound rotor motor is an induction machine where the rotor comprises a set of coils that are terminated in sliprings to which external impedances can be connected. The slip ringsbrushes allow external resistors to be connected in. The slip ring induction motors usually have a phasewound rotor. The construction of a stator is the same for both the squirrel cage and slip ring induction motor. Pdf design and analysis of drive system with slip ring induction. What are slip rings and why do some motors use them. It also requires meticulous and periodic maintenance of the brushes, brush gear, sliprings, external rotor resistances etc. Another way of saying this is that it has zero slip under usual operating conditions. A slipring motor is expensive, as are its controls, compared to a squirrel cage motor.
Jul 24, 2017 slip rings and brushes are used to conduct current to the rotor. What is synchronous motor and types electrical mastar. Mathematical analysis initially, the electromagnetic torque is developed by a hysteresis motor by virtue of the eddycurrent loss. What is the working principle of slip ring induction motor. Woundrotor motors can be started with low inrush current, by inserting high resistance into the rotor circuit. Formally, it is an electric transmission device that allows energy flow between two electrical rotating parts, such as in a motor. Nov 27, 2019 an electrical motor is an electromechanical device which converts electrical energy into mechanical energy. Overview an important function of the power train is. 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%. A woundrotor motor, also known as slip ring rotor motor, is a type of induction motor where the rotor windings are connected through slip rings to external resistance. The operation of the squirrel cage induction motor is similar to transformer having. Except some additional functions takes place in this motor which adds an advantage. Slip ring motor 5 frame size rated power duty cycle rated speed stator current rotor voltage rotor current pn kw % ed nn min1 i1 a u2 v i2 a 3en315sg 04 90 100 1478 171 310 177.
A slipring motor also requires a larger space for the motor and its controls. 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. But the basic components of a slip ring are the ring and the brushes. The slip ring rotor was developed after a decade or so. Slip power recovery system in three phase slip ring. Slip in induction motor is the relative speed between the rotating magnetic flux and rotor expressed in terms of per unit synchronous speed.
The slip ring induction motor has two distinctly separate parts, one is the stator and other is the rotor. Introduction types of electrical machines types of 3ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. However, the rotor construction of the slip ring motor is quite interesting. The stator circuit is rated as same in the squirrel cage motor, but the rotor is rated in frame voltage or short circuit current. A slip ring is an electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure. Squirrel cage motors have a rotor with short circuited bars whereas slipring motors have wound rotors having three windings each connected in star. Depending on type of workload there are various type of starters for a slip ring induction motor. Three phase slip ring induction motor a wound rotor or slip ring motor has a 3phase winding, similar to the stator winding.
The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. It also requires meticulous and periodic maintenance of the brushes, brush gear, slip rings, external rotor resistances etc. The working of this motor is similar to that of a normal motor. 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.
Starting of slip ring induction motor explained in an easy. The slip ring, also called electrical slip ring, collecting slip ring or rotary joint, which is a kind of specialized rotatable connector and a kind of component that can transmit power and signal. Obviously, we need firstly to know about the operation principle and internal structure of the slip ring. The working principles and stator construction of the slip ring induction motor are exactly the same as that of the squirrel cage motor.
The rotor of the slip ring induction motor is also cylindrical or constructed of lamination. Learn more about the construction and operation of a slip ring induction motor. Explain the construction and working principle of a linear reluctance motor b hysteresis motor. A slip ring in electrical engineering terms is a method of making an electrical connection through a rotating assembly. Y provides smooth and stepless cutting of resistance in rotor circuit of the motor, reducing starting current and increasing starting torque of slipring induction motor. They run at a constant speed from noload to the full load. Lecture 6 three phase induction motors cairo university. Using the values of the starting resistors used, actual starting torque can be calculated. When running under normal conditions, the slip rings are shortcircuited, using an external metal collar, which is pushed along the shaft to connect the rings. The three phase induction motor is the most widely used electrical motor. The speed of a synchronous motor is determined by the following formula.
Ysalient features y robust and nonflammable construction. These types of motors are known as selfstarting induction motors. 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. Its operation is based on the principle that when a current carrying conductor is placed in a. The main difference in a slip ring induction motor is on the rotor construction and usage. Starters limit the starting current in an induction motor which goes 56 times of full load current as slip remains 1. The set of rings are a complete electrical circuit within the motor.
The slip ring induction motor could be used for industrial wires where variable speed and high starting torque are prime requirements. In normal conditions, the slip ring motor functions like a squirrel cage motor. 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 resistance. But in an induction motor only the stator winding is fed with an ac supply. The slip ringsbrushes allow external resistors to be connected in series with the winding. It is very commonly used in industries because it is very cheap, robust, efficient, and reliable. To overcome this problem, the slip ring induction motor comes into the picture. Slip ring motors are the motors of choice whenever high starting torque or low starting current are required. Slip power recovery system in three phase slip ring induction. That is to say, the thicker the hysteresis ring becomes the larger the rotational hysteresis increases and to make matters worse, the output of the thicker ring motor becomes less than that of thin rotor motor.
The rotor terminals are connected to three slip rings which turn with the. Normally, we use the motors in industrial drives because they are rugged, reliable and economical. Rarely 5% 10% slip ring motors are used in industries because it has several disadvantages like it required. The rotor resistance per phase of the winding is 0. Carbon brush performance on slip rings mining electrical. Jun 06, 2015 starting of slipring motors these motors are practically always started with full line voltage applied across the stator terminals. Dosto maine aapse share kiya hai ki slip ring motor kayse kam karta haiy ummind haiy ki ye video aapko pasand aayega app subscribe technical gyan. Nov 02, 2017 dosto maine aapse share kiya hai ki slip ring motor kayse kam karta haiy ummind haiy ki ye video aapko pasand aayega app subscribe technical gyan.
In this chapter, we shall focus our attention on the construction, working and. Induction motor seminar ppt, pdf report study mafia. A synchronous electric motor is an ac motor distinguished by a rotor spinning with coils passing magnets at the same rate as the alternating current and resulting magnetic field which drives it. A slipring motor also requires a larger space for the motor and its.
The rotor poles connect to each other and move at the same speed hence the name synchronous motor. It has very simple and extremely rugged, almost unbreakable construction especially squirrel. The stator of an induction motor is, in principle, the same as that of a. Maximum starting can be attained in the slip ring motor compared to squirrel cage motor by inserting an external resistance in each phase of the rotor circuit and cutting the resistance during starting. In this chapter, we shall focus our attention on the construction, working and characteristics of commonly used singlephase motors. Squirrel cage induction motor slip ring induction motor 2. Explain the rotor rheostat control of 3 phase slip ring. Stator winding can be either star or delta connected depending upon the design. As discussed earlier, a slip ring induction motor is an asynchronous motor, as the rotor never runs in synchronous speed with the stator poles. Starting of slipring motors these motors are practically always started with full line voltage applied across the stator terminals. Slip ring induction motor fundamentals pnpntransistor. Slip ring induction motor working principle electrical mastar. Why are there two different designs of rotor construction for induction motors.
What external resistance per phase must be added in the rotor circuit so that the motor now runs ate a slip of 17. Slip ring motor conversion to vsd driven standard squirrel. The shortcircuit current of a small 3phase induction motor is 3 times the fullload currents. The poles of the stator are arranged in a manner that they create a rotating electromagnetic field when w gives a. In a dc motor, supply is needed to be given for the stator winding as well as the rotor winding. Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. Slip power losses are more during speed control due to use of variable resistance rheostat in. The value of starting current is adjusted by introducing a variable resistance in the rotor circuit. The value of slip in induction motor is can never be zero. Determine the starting torque as a percentage of fullload torque if fullload slip is 3 per cent. The principle of operation of the induction machine is. Woundrotor motors can be started with low inrush current, by inserting high resistance. The slip ring rotor chamber has two modification openings. The controlling resistance is in the form of a rheostat, connected in star fig.
The slip rings are used to in conjunction with the brushes to deliver a current to the rotor. In three phase induction motor, the power is transferred from stator to. By putting resistance in series with the rotor windings, the starting current can be kept low while mainta. The value for k is different for each slip ring motor. Chapter 11 drive lines, differentials, drive axles, and. Menzel slip ring motors, also called wound rotor motors, are available in all current motor cooling and protection types for lowvoltage from 75 kw as well as medium and high voltage up to 15000 kw. Pdf the use of squirrel cage motor for traction has revolutionised the motive power of. A slip ring can be used in any electromechanical system that requires rotation while transmitting power or signals. The operating principle and internal structure of the slip ring. Three phase slip ring induction motor my tech info. A slip ring motor also requires a larger space for the motor and its. An 8 pole, 50 hz slip ring induction motor runs at a slip of 2. Slip ring motor fundamentals bright hub engineering. This research study has the impact of the principle of slip power recovery drive particularly to reduce the power losses at output terminals of slip ring induction motor due to the output.