Troubles with the induction motors are generally divided into two categories. Free download induction motor seminar ppt, pdf report. 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. A 480v, 60 hz, 6pole, threephase, deltaconnected induction motor has the. The most common type of ac motor being used throughout the work today is the induction motor. Necessity of starter function of starter methods of starting 3. Relative humidity shall be below 95%rh for totallyenclosed types, and below. Before troubleshooting the 3 phase induction motor, we must have to know about the 3 phase induction motor, star delta starter and its connection diagram. This troubleshooting guide can also be applied to other types of three phase induction motors. To solve this problem, this method will not be applied to the totality of the signal spectrum but only to a bandwidth of specified frequency.
Three phase armature winding is assembled in these holes. A 3 phase induction motor can be used for different applications with various speed and load requirements. The stator separate from rotor by small air gap have ranges from 0. A threephase induction motor problem enginuity systems. For this example, refer to the motor equivalent circuit and calculations described above. The 3phase set of currents, each of equal magnitude and with a phase difference of 120 o, flow in the stator windings and generate a rotating field will constant magnitude. This represents the main winding of the machine and is to be connected to a 3 phase balanced supply. One single phase wattmeter plus miscellaneous apparatus as needed.
When three phase stator winding of an induction motor is energized from a 3 phase supply, a rotating magnetic field is set up which rotates around the stator at synchronous speed ns. This is plc program for forward and reverse control for 3 phase asynchronous motor. 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. 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. T2 three phase induction motor construction encompassing. A three phase, 12 pole, salient pole alternator is coupled to a diesel engine running at 500 rpm. Ac induction motors are also the most common motors used in main powered home appliances. Single phase induction motors arenot a selfstarting motor, and three phase induction motor are a selfstarting motor. A 2pole, 3phase induction motor delivers 37 hp at the shaft at a speed of 2850.
The working of the threephase induction motor is based on the principle of electromagnetic induction. Solved problems on armature of a dc machine continuation of chapter 2vk. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. Here we are giving you only overview on 3 phases induction motor. Pdf three phase induction motor incipient rotors faults detection.
It is required to reduce the speed of the motor to rpm by inserting resistances in the rotor circuit. Choose editselectobjectby clicking, and then select the object groups phb and phreb. There are lots of motors and conveyors used in industries for different purposes in some cases motors or conveyors need forward and reverse operation for some control purpose. As the current passes through the coils on opposite sides of the stator, a twopole electromagnet is established, creating a twopole motor. Slots are pressed out on the internal periphery of the stator laminations.
Torque equation of a three phase induction motor duration. To construct the circle diagram three tests are to be performed, namely a noload test. The table below gives the commonly encountered problems in 3 phase squirrel cage induction motors, cause of problems and what remedy to apply to bring the motor back to production. They are found everywhere from a small workshop to a large manufacturing industry. Induction motor solved problems examples, torque, starting torque, power developed. Find the percentage slip and number of poles of the induction motor. Form noload test i 0 is known and f 0 is found out as taking all quantities on per phase values. The open circuit voltage on open circuit between the slip rings 0 volts. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. In a 3 phase ac induction motor, there are three stator windings, each usually in two halves, with the rotor winding shortcircuited by end rings. Chapter 3 induction motor and different speed control methods page no 3. Braking of three phase induction motors is required in many industrial applications.
Induction motor problems and solutions pdf 3 phase induction motor pdf three phase induction motor the wound rotor induction motor speed control of induction motor three phase induction motor diagram blocked circle diagram of an induction motor speed control of induction motor by vf method single phase induction motor pdf free download speed control of three phase induction motor. They run at a constant speed from noload to the full load. Applications of three phase induction motors of size varying from half a kilowatt to thousands of kilowatts are numerous. Solve phase a independent of the other phases total system power s 3 v i if desired, phase b and c values can be determined by inspection i. Design methodology the design process of induction motor is an iterative process. You should also make a dc measurement of stator winding linetoline resistance using a dmm. For a 3 phase induction motor, maximum torque is twice the fullload torque and starting torque is 1. Vibration testing of motor after it has started running. Testing and inspection of surge protection devices. To draw circle diagram for a three phase induction motor. Use the approximate equivalent circuit a determine the synchronous speed a c determine the input current.
The machine designer first assumes the efficiency and power factor at the rated condition. Air gap length is a major part of induction motor design. This paper introduces braking of three phase induction motors using. Induction motor seminar ppt, pdf report study mafia. A portion of rotating magnetic field in a three phase.
It supplies an induction motor which has a full load speed of 1440 rpm. One singlephase wattmeter plus miscellaneous apparatus as needed. An electrical motor is an electromechanical device which converts electrical energy into mechanical energy. 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. Design of a three phase squirrel cage induction motor for.
An induction motor also known as an asynchronous motor is a commonly used ac electric motor. The shaft output of a three phase 60 hz induction motor is 80 kw. There are single phase induction motors and three phase induction motors. The most popular type is the 3 phase, squirrelcage ac induction motor. Figure2 shows the connection of a 3phase induction motor with a star delta starter. The open circuit voltage on open circuit between the slip rings 0. Problem 1 the perphase parameters of the equivalent circuit, for a 400v, 60hz, 3 phases, y connected, 4 pole induction motor. One is the electrical faults, such as the various faults of switches, buttons, fuses, electric brushes, stator winding, rotor, starting equipment and so on. The method achieved low starting current by first connecting the stator winding in star configuration, and then after the motor reaches a certain speed, throw switch changes the winding arrangements from star to delta configuration. The three phase induction motor is the extensively used for various kinds of industrial drives. 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. Resistance tests on resistance temperature detector rtd circuits. Ansoft rmxprt application note a threephase induction motor problem. You should also make a dc measurement of stator winding linetoline resistance.
Record all nameplate information for the induction motor. We need to give double excitation to make a dc motor to rotate. Compare the rotation of this motor with that in figure 164. Starting of induction motor for induction motors, the starting torque lrt is approximately proportional to the square of the starting current lra drawn from the line. Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed.
640 122 5 1108 1249 1288 1529 960 459 1043 814 1059 563 161 1180 768 672 500 424 1148 561 94 989 1365 1104 462 25 1091 1071 1222 1267 526 742 913 1302 577