The inverter motor drive analysis imda solution from tektronix helps engineers design better and more efficient threephase motor drive systems, taking full advantage of the advanced user interface, six or eight analog input channels, and high res mode 16 bits on the 5 series mso. The solutions that use threephase induction motors were taken into consideration with different types of rotors. For a glossary of the symbols used, please, refer to section 9. These motor drives are designed to be used in conjunction with a 3phase induction motor. Selection of induction motors for industrial applications. A variablefrequency drive is a device used in a drive system consisting of the following three main subsystems. Pdf simulation of threephase induction motor drives using. Hence effective value of resistance per phase is given by 4. A forerunner of the 3phase induction motor was invented by nikola tesla sometime before 1889. Induction motors im has always been preferred for its reliability, ruggedness and easier in maintenance. A 480v, 60 hz, 6pole, three phase, deltaconnected induction motor has the following. An induction motor essentially consists of two main parts. Torque was found to be constant for various rotor speeds. By far the most commonly used ac motor is the induction motor.
Physical layout of induction motor in an induction motor induction refers the field in the rotor is induced by the stator currents and asynchronous refers that the rotor speed is not equal to the stator speed. Ac induction motors are also the most common motors used in main. The rotor will constantly be turning to align its magnetic field with that of the stator field. These products, hallmarked for quality, performance, and durability, can be customized to meet the most demanding applications.
The stator of an induction motor is in principle, the same as that of a synchronous motor or generator. Faulttolerant operating strategies applied to threephase inductionmotor drives. If the speeds become equal, there would be no such relative speed, so no emf induced in the rotor, and no current would be flowing, and therefore no torque would be generated. Vf control of squirrel cage induction motor drives without flux or torque me. Design of vfd drive for a 3phase induction motor open. The input power of the induction motor drive is given by the formula shown below.
In very simple words induction motors can be described as a three phase, self starting constant speed ac motors. You should also make a dc measurement of stator winding linetoline resistance. Curiously, the stators for the 3phase induction motor and the dc brushless motor are virtually identical. Washing machine threephase ac induction motor drive, rev. Safety information 1 description 2 transport, assembly, and connection 3 startup 4 operation 5 faults 6 maintenance 7 spare parts 8 notes 9 threephase induction motor. Singlephase induction motors are used extensively for smaller loads, such as household appliances like fans. 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. The friction and windage losses are 600 w, the core losses are 1800 w, and the stray losses are negligible. Two digital multimeters and fluke power quality meter with banana cables from the. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. In very simple words induction motors can be described as a threephase, selfstarting constant speed ac motors. It is made up of a number of stampings, which are slotted to receive the windings. Pdf this research presents two mathematical based optimal control systems for induction motor drives leading to stator current optimization and.
The circuit is capable of supplying single phase induction motor inductive or resistive load with varying ac voltage. The most popular type is the 3 phase, squirrelcage ac induction motor. The stator carries a 3 phase winding and is fed from a 3 phase supply. There are two types of induction motors, one with wound type rotor, also called slipring motor and another one with squirrelcage rotor. This application note also covers the basics of induction motors and different types of induction motors. The stator has a threephase winding, and embedded in slots. Presented here is a robust system for switching onoff, varying the speed and direction of rotation of an industrial 3 phase induction motor using vfd and plc. The ac electric motor used in a vfd system is usually a threephase induction motor. The rotor of three phase induction motor consists of a cylindrical laminated core with parallel slots that can carry conductors. The major difference between them is that transformer is static in nature i. An induction motor s rotor can be either wound type or squirrelcage type. The working of the threephase induction motor is based on the principle of electromagnetic induction.
It is a maintenancefree, less noisy and efficient motor. The conductors are heavy copper or aluminum bars fitted in each slot and shortcircuited by the end rings. If the induction motor is operating in the linear magnetic region, the lm is constant. A 3phase induction motor uses current delivered in three phases in a sequence into the coils of a stator to create a rotating magnetic field. The working of the three phase induction motor is based on the principle of electromagnetic induction.
The magnitude of the load current depends on the nature of the load impedance. The concepts, ideas, and equipment used in the motor drives industry are easily applicable to harnessing energy from alternate sources, including solar energy and wind energy. Washing machine three phase ac induction motor drive, rev. Hence, an utmost care should be exercised in selection of most appropriate type of motor considering number of technical factors for each application, so that the motor would provide desired and optimum performance. Induction motor drives starting braking speed control of. The motor drives a mechanical load at a speed of 1170 rpm. A portion of rotating magnetic field in a three phase. Block diagram of speed control of induction motor using pwm technique. It supplies an induction motor ich has a full load speed of 144wh 0 rpm.
This induces an electric field in a coil or squirrel cage to drive a rotor. Because these motors typically only have an onoff state of operation, a vfd is needed if multiple operation speeds are desired. Torque developed by 3 phase induction motor is directly proportional to the square of the stator voltage as given by the equation. One single phase wattmeter plus miscellaneous apparatus as needed. The stator carries a 3phase winding and is fed from a 3phase supply. These motor drives are designed to be used in conjunction with a 3 phase induction motor. One singlephase wattmeter plus miscellaneous apparatus as needed.
The three hot leads are usually labeled u1, v1, and w1 and the final lead is labeled ground. Pdf maximum torque control mtc is a new method applied for control of induction motor drives. When threephase 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. To obtain the load performance characteristics of a three phase squirrelcage induction motor. To do so, a vfd variable frequency drive is used for controlling the speed of a three phase induction motor with variable load attached to the motor. Some types of single phase motors or synchronous motors can be advantageous. Torque and slip behavior of singlephase induction motors driven. The applications for these motors cover almost every stage of manufacturing and processing. This paper presents the simulation of three phase induction motor drives using indirect field oriented control ifoc in psim environment.
Analysis of variable frequency three phase induction motor drive. Record all nameplate information for the induction motor. Iv induction motor drives 1 unit iv induction motor drives. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. Threephase squirrelcage induction motors are widely used as industrial drives because they are selfstarting, reliable and economical. Some types of singlephase motors or synchronous motors can be advantageous. This application note describes the design of a 3 phase ac. The 3phase set of currents, each of equal magnitude and with a phase. Both have three sets of distributed windings that are inserted within the stator core. Lecture series on industrial automation and control by prof. The basic idea of an electric motor is to generate two magnetic fields. The torque generated in the rotor of a 3phase induction motor is proportional to the flux generated by each stator pole, the rotor current and the power factor of the rotor. 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.
Single phase induction motors are used extensively for smaller loads, such as household appliances like fans. Pdf maximum torque control of 3phase induction motor drives. The main aim of the project dealt with the concept of speed control of a three phase induction motor with energy saving. Load tests on a three phase induction motor and measurement of the inrush current objectives. Washing machine threephase ac induction motor drive. If your motor has three black leads and a green lead then it is likely three phases. The threephase ac voltage produced by the inverter is applied to the induction motor windings. Start induction motor dynamic and steadystate performance of a.
An843, speed control of 3phase induction motor using pic18 mcus. The torque generated in the rotor of a 3 phase induction motor is proportional to the flux generated by each stator pole, the rotor current and the power factor of the rotor. His document describes the design road taken when looking at a 3phase variable frequency drive vfd. The threephase induction motor is the extensively used for various kinds of industrial drives. Before discussing about the induction motor drives we have to understand and know about induction motors.
Hence, an utmost care should be exercised in selection of most appropriate type of motor considering number of technical factors for each application, so that the motor would provide desired and. The most popular type is the 3phase, squirrelcage ac induction motor. Find the percentage slip and number of poles of the induction motor. This final thesis will mostly be dedicated to induction motors but also to synchronous permanent magnet and reluctance motors. The asynchronous machine is well known about natural. Mar, 2018 if your motor has three black leads and a green lead then it is likely three phases. An introduction there are various methods for the speed control of an induction motor. The input voltage of the voltage source inverter remains constant, and their output voltage is independent of the load. Ac motor, main drive controller assembly, and driveoperator interface. Pdf faulttolerant operating strategies applied to three. Y2 series three phase induction motors dimensions and rated output are in conformity with international standard iec 600721.
The im drives controlled with the vector control method has found wide acceptance in the industry. To measure the inrush current when the motor starts. The stator copper losses are 2 kw, and the rotor copper losses are 700 w. The ac electric motor used in a vfd system is usually a three phase induction motor. Speed control of induction motor using pwm technique. A 480v, 60 hz, 50hp, three phase induction motor is drawing 60 a at 0. The stator and rotor l eakage impedances are neglected as compared to inductor ld.
Nov 27, 2019 thus from the working principle of three phase induction motor, it may be observed that the rotor speed should not reach the synchronous speed produced by the stator. Ac induction motors are also the most common motors used in main powered home appliances. Direct torque control dtc is a technique used in variable frequency drives. Pdf threephase induction motor stator current optimization. Jun 08, 2019 before discussing, induction motor drives its important to understand and know about induction motors. The voltage source inverter is defined as the inverter which takes a variable frequency from a dc supply. A 3 phase induction motor can be used for different applications with various speed and load requirements.
They can be used in control of motors used in conveyors and other machinery. Controlling 3 phase induction motor using vfd and plc. A 3 phase induction motor derives its name from the fact that the rotor current is induced by the magnetic field, instead of electrical connections the operating principle of a 3 phase induction motor is based on the production of r. Thus from the working principle of three phase induction motor, it may be observed that the rotor speed should not reach the synchronous speed produced by the stator. Selection of induction motors for industrial applications part 1 photo credit. The braking of an induction motor is explained below in details. The rotor of the squirrel cage three phase induction motor is cylindrical in shape and have slots on. Design strategy for a 3phase variable frequency drive vfd. Maximum torque control mtc is a new method applied for control of induction motor drives. An843, speed control of 3phase induction motor using. An induction motors rotor can be either wound type or squirrelcage type.
Simplified steadystateequivalent circuit of induction motor. How to run 3 phase motor with 1 phase power supply by. The reason for describing induction motors as constant speed is because normally these motors have a constant speed depending. Induction motor is now called the racehorse of the industry 1. We use here delta ac motor drive for its operation. Before discussing, induction motor drives its important to understand and know about induction motors.
The drive is controlled by dc voltage supplying a converter in the range below nominal speed and by a. In cage rotor type induction motors the rotor has a squirrel cagelike structure with shorted end rings. A three phase, 12 pole, salient pole alternator is coupled to a diesel engine running at 500 rpm. Volume3 issue4, september 2014 speed control of three. Thus, there is an inherent danger in blindly operating a singlephase induction motor from one phase of a threephase drive. Various automation processes in the industry need control of ac induction motors using ac drives. It comes from estimating the magnetic flux from the voltage and current of the motor. This paper presents the simulation of threephase induction motor drives using indirect field oriented control ifoc in psim environment.
1507 1104 279 521 357 1258 1494 590 618 477 187 832 1017 1415 620 182 845 546 938 1477 747 118 1391 1362 236 475 1443 1009 910 1342 434 161 624 1156 1379 1162 1133 737