Types of 3 phase induction motor pdf file

The squirrel cage motor is mostly started by stardelta stater and hence the stator of squirrel cage motor are delta connected. The induction motor is the most widely used motor in the industry due to its simple and rugged construction. There are two types of 3 phase induction motors based on the type of construction of rotor. Determination of the losses in induction machines due to harmonics pdf. Ap1609710 different pwm for three phase acim 060803 for pdf. Servicing usually requires that the motor be sent to a motor repair shop for rewinding. Induction motor 1 chapter 3 induction motor bee23 electrical machine power system 2 learning outcomes. Induction motor seminar ppt, pdf report study mafia. The first ac commutatorfree threephase induction motors were. Explain starting methods of 3 phase induction motor. This induces an electric field in a coil or squirrel cage to drive a rotor. The speed of this rotating magnetic field is called the synchronous speed.

Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. Compare the rotation of this motor with that in figure 164. For instance, a 100 horsepower, three phase motor operating with voltages of 598, 575 and 552 applied at the motor terminals is running with a 4% voltage unbalance 100 x 23575. In a good preventive maintenance program with detailed checks, the person in charge should have a record card on file for every motor in the plant. An induction motor or asynchronous motor is an ac electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor im is a type of asynchronous ac motor where power is supplied to. The rotor is connected to the mechanical load through the shaft. The magnet is spun by a 3 phase ac motor with no rotor voltage 4. A 3 phase induction motor has two main parts i stator and ii rotor. The individual voltages, therefore, add to produce a single phase ac voltage. For slip ring induction motor, by providing external resistance in rotor circuit we can also limit starting current. Two types of induction motors single phase induction motor.

A 3 phase, y connected, 460 volt line to line, 25 horsepower, 60 hz, 8 pole induction motor has the following constants, in ohms per phase referred to the stator. Rfoc of a single phase induction motor im with two asymmetrical main and auxiliary windings. The singlephase induction motor is much the same in construction as the threephase motor. Both types are popular but for larger sizes the induction motor is the most highly. They run at a constant speed from noload to the full load.

Three phase induction motors draw six or more times rated current when started at rated voltage. One single phase wattmeter plus miscellaneous apparatus as needed. The single phase motor stator has a laminated iron core with two windings arranged perpendicularly. It requires least maintenance as compared to other electrical motors. The rotors of the three phase induction motor are further classified as. To get a good understanding of the working principle of a three phase. Threephase motors have fewer components that may malfunction than other motor types. A wound rotor, has a 3phase winding similar to the stator winding. It is desired to install a 3phase cage induction motor restricting the maximum line current drawn from a 400 v 3phase supply to 120 a. The ideal motor maintenance program aims at preventing breakdowns rather than repairing them. Refer back to this diagram as the operational requirements of the singlephase motor are discussed. Difference between single phase and three phase induction. The rotor of three phase induction motor consists of a cylindrical laminated core with parallel slots that can carry conductors.

An induction motors rotor can be either wound type or squirrel cage type. You should also make a dc measurement of stator winding linetoline resistance. The starting methods of three phase induction motor generally are directonline starting, reducedvoltage starting and soft starter. Here we have classified these faults in three types, but these are further sub divided.

They can be used in control of motors used in conveyors and other machinery. Perform an analysis on induction machines which is the most rugged and the most. The stator in the electric motor generates the field current which rotates in a stable speed based on the ac frequency. Safe running speed for the squirrelcage induction motors. One way to reduce the starting current is to start the motor at reduced voltage. Generally, two types of induction motors are used in our industry such as wound rotor and squirrel cage rotor, but their faults are almost same. The conductors are heavy copper or aluminum bars fitted in each slot and shortcircuited by the end rings.

Unless otherwise the name plate specifies, all the squirrelcage, 3 phase, induction motors lower than v and smaller than 315 frame size can safely run continuously at the speed in the table below. Slip ring rotor or wound rotor or phase wound rotor. An electric motor converts electrical energy into a mechanical energy which is then supplied to different types of loads. There are two types of rotors which are employed in 3 phase induction motor. My original aim was to bridge the gap between specialist textbooks which are pitched at a level too academic for the average user and the more prosaic handbooks, which are full of useful detail but provide. The induction motor stator resembles the stator of a revolving field, three phase alternator. The rotor winding terminals are connected to three slip rings which turn with the rotor. The slip ring three phase induction motor are started by inserting resistances so, the stator winding can be connected either in star or delta. Therefore, 3o motors usually operate for many years without any problems. An induction motor or asynchronous motor is an ac electric motor in which the electric current.

First of all, i am going to discuss about the construction of 3 phase induction motor and then i. 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. Methods of starting three phase induction motors as we know, once a supply is connected to a three phase induction motor a rotating magnetic field will be set up in the stator, this will link and cut the rotor bars which in turn will induce rotor currents and create a rotor field which will interact with the stator field and produce rotation. Principle of operation of single phase induction motor. The major difference between them is that transformer is static in nature i. At the end of the lecture, student should be able to. Synchronous speed is determined by the number of poles p and frequency f of power supply.

Nov 07, 2011 it protects the inner part of the machine. An843, speed control of 3phase induction motor using pic18 mcus. Some singlephase induction motors are also called squirrel cage motors because of the rotors similarity. Types and construction of three phase induction motor. Figure 3 5 shows a basic alternator with its single phase output voltage. Nov 27, 2019 an electrical motor is an electromechanical device which converts electrical energy into mechanical energy. Unit 16 electric motors objectives after studying this unit, the student will be able to state the purpose of an electric motor. It is made up of a number of stampings, which are slotted to receive the windings.

The very first thing that you should do before starting any type of maintenance on a motor is a visual inspection, a lot of times the trouble can be found just by looking, because if the problem is that bad then it should be very obvious by observation. In this application note, we will generate a third pwm in software, using a general purpose timer and an io pin resource that are readily available on the picmicro microcontroller. These types of motors are known as selfstarting induction motors. The main difference between single phase induction motor and three phase induction motor is that single phase motors are not selfstarting so they require some starting mechanism while three phase motors are selfstarting. The winding wound on the stator of three phase induction motor is also. Rotates a number of degrees with each electric pulse. An induction motor can therefore be made without electrical connections to the rotor. The working of the synchronous motor mainly depends on the 3 phase supply. An electrical motor is a device that has brought about one of the biggest advancements in the fields of engineering and technology ever since the invention. For reason of economy, most houses, offices and also rural areas are supplied with single phase a. Designation explanation of induction motor type 160 m operating conditions 1 3. The difference in speed between rotor, the synchronous speed and the rotating. Y2 series 3 phase induction motors are widely used as drive mechanism in various kinds of machineries like machine tools, pumps, fans, compressors, gear boxes, etc. Three phase induction motor faults and their causes.

When we connect the primary winding, or the stator to a 3 phase ac source. Three phase induction motor for industrial general purpose toshiba. Unit 16 electric motors washington state university. What is common to all the members of this family is that the basic physical process involved in their operation is the conversion of electromagnetic energy.

Types of single phase induction motors electronics hub. What is common to all the members of this family is that the basic physical process involved in their operation is the conversion of electromagnetic energy to mechanical energy, and vice versa. If a 3o motor is the problem, the motor is serviced or replaced. For this example, refer to the motor equivalent circuit and calculations described above. Types of single phase induction motors as mentioned above that, due to the rotating magnetic field of the stator, the induction motor. An induction motor essentially consists of two main parts. Squirrel cage induction motors a stator construction. An induction motor also known as an asynchronous motor is a commonly used ac electric motor. Three phase induction motors are constructed into two major types. Windingrotor arrangements for 3 phase induction machine three phase slip ring induction motor. Maintenance and troubleshooting three phase induction motor. In an induction motor, the electric current in the rotor needed to produce torque is obtained via electromagnetic induction. Different types of fault in three phase induction motor.

Squirrel cage induction motor and wound rotor induction motor based on the construction of rotor. Single phase induction motors are used primarily for domestic and lightindustrial applications where three phase supply is generally not available. The effect of unbalanced voltages on polyphase induction motors is equivalent to the introduction. A 3 phase induction motor can be used for different applications with various speed and load requirements. Understand the principle and the nature of single phase and 3 phase induction machines. The stator of an induction motor is in principle, the same as that of a synchronous motor or generator.

One is almost identical to that of the three phase induction motor while the other is of a form similar to that of the d. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. A wound rotor or slip ring motor has a 3phase winding, similar to the stator winding. The rotor is separated from the stator by a small airgap which ranges from 0. The stator carries a 3 phase winding and is fed from a 3 phase supply. The threephase induction motor is the extensively used for various kinds of industrial drives.

There are two basic reasons for the use of single phase motors rather than 3 phase motors. Uses soft magnet rotor that is magnetized by the application of current in the stator coils 3. Induction motor different types of duties in motor construction how induction motor as a rotating transformer how to run three phase motor on single phase power supply induction motor interview question slip ring induction motor srim vs squirrel cage induction motor scim synchronous watt types of encloser employed in induction motor types of insulation class. Such high currents may pose serious problems for the motor and the electrical system when large motors are started. Today we are going to made available a powerpoint presentation file for all. Analysis of three phase induction motors controlled by thyristors. Three phase induction motors are further divided into two types. In this case, power flows from the mechanical system, to the rotor circuit, then across the air gap to the stator circuit and external electrical system.

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. The stator or the stationary part consists of three phase winding held in place in the slots of a laminated steel core which is enclosed and supported by a cast iron or a steel frame as shown in fig. Phase wound induction motor slipring induction motor. Free download induction motor seminar ppt, pdf report. For better understanding, the basic operation and control principle of 3 phase ac induction motors is described in section 2. Types of electric motors electric motors dc motors other motors h ac motors s unt motor separately excited.

Single phase induction motor the single phase induction machine is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth. Systematic and periodic inspections of motors are necessary to ensure best operating results. Squirrel cage wound rotor with slip rings the rotating magnetic field. A three phase induction motor runs on a three phase ac supply.

The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. This application note also covers the basics of induction motors and different types of induction motors. For induction motor, 0 three phase power supply is connected to the three phase stator winding of induction motor, a rotating magnetic field is produced in the air gap. Therefore, induction motor protection plays an important role in its long life service. Record all nameplate information for the induction motor. A 3 phase induction motor uses current delivered in three phases in a sequence into the coils of a stator to create a rotating magnetic field. The stator of an induction motor consists of 3 phase windings, which when connected to a 3 phase supply creates a rotating magnetic field. Ac induction motors are also the most common motors used in main powered home appliances.

Starting method for induction motors a 3 phase induction motor is theoretically self starting. After looking at some of the considerations for fullvoltage starting, we will consider several. Directonline starting this kind of starting mode is the most basic and simplest in the motor starting. In this application note, the methods to generate different pwm waveforms for 3 phase ac induction motor using an infineon 16bit microcontroller xc164cs are introduced. As previously, we have covered a lot of important topics.

Three phase induction motor provided with the different starter like stardelta starter, autotransformer starter and dol starter etc. Consequently, the rated output of 100 horsepower should be derated to approximately 82 hp to reduce the possibility of damage to the motor. Induction motor totallyenclosed fancooled nema standard epact three phase induction motors sdesign versatility teco totally enclosed fan cooled squirrelcage induction motors are designed, manufactured and tested to meet or exceed the latest nema, ieee, csa and. Furthermore, single phase motor requires only single phase supply so they produce an alternating magnetic field whereas three phase motor requires three phase supply so they. It is true that single phase motors are less efficient substitute for 3 phase motors but 3 phase power is normally. Download 3 phase induction motor powerpoint presentation. Unlike a 3 phase induction motor, a single phase induction motor is not self starting but requires some starting means. Just like any other motor, a 3 phase induction motor also consists of a stator and a rotor. What is the operating principle of a 3ph induction motor.