Speed control of induction motor using vfd pdf file

They can be used in control of motors used in conveyors and other machinery. Huge energy savings potential operating centrifugal fans, pumps and compressors vary frequency of electrical supply to an induction motor to vary the motor speed. I am experimenting when i get the chance with a pic based control of shaded pole motors using a burst method instead of phase angle control as is done with a dimmer. If you continue browsing the site, you agree to the use of cookies on this website. Speed of a dc shunt motor can be varied very easily with good efficiency, but in case of induction motors, speed reduction is accompanied by a corresponding loss of efficiency and poor power factor. It certainly leads to the best performance and high efficiency of the induction motor. Various control schemes have been used to operate the induction motor in speed and position control modes of operation using plc programming. We know that t he speed of the induction motor is given by, from the above equation, the speed of the motor can be controlled by changing supply frequency and by changing number of poles in the stator. Induction motors were invented by nikola tesla in 1888 while he was a college student. Variable speed control of ac electrical machines makes use of forcedcommutated electronic switches such as igbts, mosfets, and gtos. The paper is about controlling the speed of a three phase induction motor using variable frequency drive power flex 4m through programmable logic. In this post let us see what are the various methods to control the speed of induction motor.

It gives the possibility to use it to show people about the control of an induction motor and the step towards electric cars is easily made. This application note explains how these microcontrollers can be used for 3phase ac induction motor control. The output control method of a speed control circuit can be divided roughly into two groups. Variable speed drives vsd are considered to be having highest energy saving potential and are widely replacing mechanical, hydraulic and dc motor speed control system.

It is not only beneficial for the working quality, but also for energy saving. The speed control of induction motor is done at the price of reduce in efficiency and low power factor. Vfds can control multiple motors many applications use one or more motors operating in parallel at the same desired speed. G120 power module 240 variable frequency drive, a threephase induction motor and a panel board has been developed, configured and integrated together for the monitoring and control of the motor. Variable frequency drives vfds are electronic power controllers that allow for precise control of the speed of alternating current ac induction motors that drive a variety of rotating machines including fans, pumps and compressors. This is plc program to control motor speed using vfd drive. Jun 06, 2016 speed control of induction motor using plc and vfd 1. Well talk about the motor and vfd and wire it up on the bench for testing before we tear into the lathe. Controlling 3phase induction motors using vfd and plc. Speed control of induction motor 7 ways to control. As induction motors are widely being used, their speed control may be required in many applications. These motors are used in most heating, ventilation and airconditioning hvac systems and account for a significant portion of the total hvac energy. Speed control of induction motor by using variable frequency. To control and monitor variable frequency drives using plc for.

How to save energy with vfds variable frequency drives. Controlling speed of motor using vfd electrical engineering. Vf control of 3phase induction motors using pic16f7x7. Speed control of induction motor using pwm technique. Abstract the induction motor in industries as well as in residential purposes plays an. The control methods for induction motors can be divided into two parts. Vf control of 3phase induction motors using pic16f7x7 microcontrollers. A variable frequency drive vfd also referred to as a variable speed drive is a type of system through which speed of an induction motor can be varied. Here, vfd carry outs the speed control by using vf method explained in earlier sections. Various automation processes in the industry need control of ac induction motors using ac drives. Vfds may be referred to by a variety of other names, such as variable speed drives, adjustable speed drives, or inverters. From the vfd basics theory, we know a vfd can control the speed of the motor during the start and stop cycle, as well as throughout the running cycle by outputting adjustable frequency. Introduction this application note describes the design of a 3phase ac induction motor drive with volts per hertz control in closedloop vhz cl. Scalar control is the term used to describe a simpler form of motor control, using nonvectorcontrolled drive schemes.

Will a dimmer switch or transformer control an induction motors speed. Variable frequency drives ressources naturelles canada. The full load torque of a motor is the torque necessary to produce its rated horsepower at fullload speed. The vfd not only controls the motor speed, but can improve the motor s dynamic and. Speed control of a three phase induction motor using pwm. An induction motor is practically a constant speed motor, that means, for the entire loading range, change in speed of the motor is quite small. The main methods employed for speed control of induction motors are as follows. A variablefrequency drive is a device used in a drive system consisting of the following three main subsystems.

It has highefficiency which drives ac induction motor with pwm modulated sinusoidal voltage and design of a low cost. Often in the industry, need arises for controlling the speed of a 3 phase induction motor. In the variable frequency drive itself are the most basic components present. Another approach is to use a rpm motor and operating it between 15 hz and 75 hz. The proposed system is a matlab simulink model, which is a closed loop model designed to achieve desired speed control of a threephase induction motor by varying its frequency. With the invention of variable voltage variable frequency drives vvvf, the use of an induction motor has increased. Ac motor, main drive controller assembly, and driveoperator interface 210211. Sometimes theyre talking about induction motors, other times not, and they dont specify which is which, or even which induction motor type they are talking about. Variable frequency drives a variable frequency drive is a motor control device that protects and controls the speed of ac induction motors. Why use variable frequency drive for induction motor. A variable frequency drive vfd is used to control the speed of motor with the primary voltage control method. How to control the speed of an induction motor quora.

Pdf the electrical machine analysis and performance calculation is a very important aspect of efficient drive system design. Using these commands, drives ramp the motor to the desired speed and decelerate it to the correct the position. The mathematical model of single phase induction motor is developed. Speed control methods of various types of speed control. The position loop is given a position command, an acceleration rate, top speed and deceleration rate. Pdf speed control of induction motor using pi and vf. How to choose the right control method for vfds machine. Circuit operation is controlled by using 8051 family microcontroller.

New product line from unitronics variable frequency drives vfds this major release enables us to meet market demands for motor and motion control solutions. If you want to control induction motor speed, save yourself a lot of grief and get a 3phase motor. Closed loop vf based speed control of induction motor. At low load motor is delivering the load with some current and thereby torque is maintained. By using an inverter type ac drive, the speed of a conventional ac motor can be varied through a wide speed range from zero through the base 60 hz speed and above often to 90 or 120 hertz. Abstract speed control of induction motor is a new technique. Closed loop vf based speed control of induction motor, in mathworks. The vfds are now commonly applied to air handlers, pumps and tower fans. As the motor begins to rotate, this current declines which ultimately produces the speed torque profile for the machine. This is why using vfd to control an induction motor was a good idea. How to program an igbt module with arduino to control a 3. This paper shows the direct online starter and speed management of 3phase induction motor through vfd. In the present day, induction motors consume between 90 to 95 percent of the motor energy used in industry. As the frequency is variable as compared with the poles of the motor therefore speed control drive is termed as variable frequency drive vfd.

Deltas ac motor drives are able to efficiently control motor speed, improve machine automation and save energy. Smartfan stratus ii is a variable frequency drive for fractional hp motors. Speed control methods of the various speed control motors. This is one reason that you rarely see 1ph vfd s, just about all of the hobby cnc community that use a induction motor spindle, use a 3ph motor with a 240v 1ph supply version vfd. Variable frequency drives vfds popular speed control devices used in industrial, commercial and residential applications. This manual is intended to help users of variable speed drives successfully install. Scalar control is relatively simple method compared to vector control.

Investigation in induction motor starting and speed control with. Vfd fundamentals copyright 2003 kilowatt classroom, llc. Matlab simulation for speed control of three phase. Motor speed can be based on an analog signal, transducer, temperature, potentiometer or modbus. Component of speed control of im by plc miniature circuit breaker mcb.

Motor speed control using vfd and plc programming ladder. This paper proposes an alternative methodology for estimating the speed of a three phase induction motor driven by a voltage source inverter, using space vector modulation under the scalar control. Voltage and frequency relationship when the frequency applied to an induction motor is reduced, the ap. It consists of a 3 phase ac to dc converter, filter circuit and dc to ac inverter. Speed control of induction motor using vector control. Different speed control methods of induction motor are explained below. Line voltage control the torque developed varies with the square of the applied voltage. Lets talk about two different load one is high load and other low load. The inverter outputs a pulsed voltage, and the pulses are smoothed by the motor coil so that a sine wave current flows to the motor to control the speed and torque of the motor. Pdf simulation and study of svpwm inverter for vfd. Each drive in its variable frequency drive vfd series is designed to meet.

Dec 10, 2012 closed loop vf based speed control of induction motor, in mathworks. These mathematics are probably too much for an arduino to perform digitally in real time. Constant pressure or flow can be maintained with pid plus programming. Pabitra kumar behera, manoj kumar behera, amit kumar sahoo, speed control of induction motor using scalar control technique, international conference on emergent trends in computing and. There are various methods for speed control of induction motors. Variable frequency drive for induction motor elprocus. Pdf speed control of induction motor drives using neural networks is presented. Simulation and study of svpwm inverter for vfd applications. Induction motor use is limited in many industrial applications requiring variable speed due to high costs incurred in methods of speed control and inefficiency of the methods used. Using a high slip motor does not provide higher starting torque when using a vfd. Thursday, september 1, 2016 to cope with the effect of the power electronics and the pulse thereof, it is usual to wind stator with specially varnished wire from supplier.

The vfd can be controlled remotely by using plcdcs systems the plc has to give set point for vfd drive to control the motor speed, this can achieved either automatically from the plc or by the operator action from the hmi. Thus by keeping the vf ratio constant, the speed of induction motor is controlled by vfd. Before discussing the methods to control the speed of three phase induction motor one should know the necessary formulas of speed. This paper specifically describes one of the methods. Speed control of a single phase induction motor using. This document describes how to connect and communicate with the. Firstly threephase induction motor drive system is simulated in various modes using matlabxilinx, then finally closed loop control of induction motor is. The control of induction motor by vfd and plc for the compacting. Can we convert normal induction motor to vfd purpose. However, there is no restriction to the phase of injected emf. Speed control of induction motor using variable frequency drive. Simulate variable speed motor control variable speed control of ac electrical machines makes use of forcedcommutated electronic switches such as igbts, mosfets, and gtos. It is hard to learn anything valueable from that page.

Motor horsepower is a relation of motor output speed and torque expressed in lbft. Frequency variation and rotor speed frequency speed in hz in rpm 20 600 25 750 30 900 35 1050 40 1200. So obviously the speed of an induction motor can be controlled by varying any of three factors namely supply frequency f, number of pole p or slip s. Will variable frequency drives with standard induction motors.

Bexperimental setup the allen bradley power flex4m ac drive is the most cost effective and smallest drives which in a compact and space saving design provide a powerful motor speed control. Speed control of induction motors the speed of an induction motor is given as n 120fp 1s. Jan 09, 2017 speed control methods of induction motor. Variable frequency drive vfd usage has increased dramatically in hvac applications.

Various induction motor speed control methods advantages. You can use variable frequency drive to control a pump and maintain a fixed flow rate, this is a key feature. Implementation of plc in vfd controlled induction motor. Vfd variable frequency drives variable speed drives. Controlling 3 phase induction motor using vfd and plc. However, present trends and increase of speed control methods of an induction motor have improved the use of induction motors in electrical drives broadly. Deltas ac motor drives are able to efficiently control motor speed. Variable frequency drive fan speed control motor drives. A vfd therefore provides continuous range process speed control as compared to the discrete speed control that gearboxes or multi speed motors provide. Various vfds with single phase 220v power supply has a lower cost than the vfd with three phase 380v, so it is relatively economic. Currently the use of threephase induction machines has been increased tremendously in industrial applications due to several methods available to control the speed and torque of the motor. As i am trying to implement the whole process in terms of hardware so, i just wanted to know how whole process works on. It is necessary that voltage emf being injected must have same frequency as of the slip frequency.

Speed control of threephase induction motor using variable frequency drive. The vast majority of motors sold today are squirrel cage induction motors. In this method, speed of an induction motor is controlled by injecting a voltage in rotor circuit. This paper is about speed control of induction motor which has very vast application in industrial sector using plc programmable logic controller and vfd variable frequency drive. For motors controlled by a variable frequency drive vfd, the control method used in large part determines a motor. The inverter first converts the input ac power to dc power and again creates ac power from the converted dc power using pwm control. May 31, 2018 today, were starting on a 3phase motor and vfd upgrade for the grizzly g0602 lathe. The ac electric motor used in a vfd system is usually a threephase induction motor. Each drive in its variable frequency drive vfd series is designed to meet specific application needs.

This means the speed torque curve looks more like a constant slope as both. For the induction motor im the technique is used as voltshertz constant. The duty cycle of pwm will control the motor using an optocoupler to trigger the triac. The main purpose of this experiment is to control the speed of a three phase induction motor using vfd through plc. It has also been observed that when change in vf occurs, then the transient period of only 0. Using one variable frequency drive vfd to control these multiple motors provides a host of advantages as summarized below. You only need to vary the pwm duty cycle to control the speed of the motor. Speed control of induction motor by variable frequency control.

By controlling the output ac frequency, it is possible to drive the motor at different speed based on the requirements. Speed control of induction motor using arduino protection vfd for project file contactsend a mail. Jan 25, 2010 these capabilities allow vfds to position a standard induction motor with encoder feedback. Induction motor and different speed control methods page no 3. East setup using navigator handheld programmer or modbus port.

We can also perform the forward and reverse rotation of induction motor. Variable frequency drive or vfd is the way that enables controlling of the speed of induction motor by applying varying frequency of ac supply voltage. Abstract induction motor are widely used in various industries. 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. Closed loop vf based speed control of induction motor file. After using vfd, the motor can realize stepless speed regulation, so as to improve the performance. Asynchronous machines fed by pulse width modulation pwm voltage sourced converters vsc are nowadays gradually replacing the dc motors and thyristor bridges. Speed control of induction motor by using inverter vfd. So i just wanted to know that can i get the paper which has exact theory of the simulation which you have implemented. A three phase induction motor is mostly a constant speed motor so its fairly not easy to control its speed. Speed control of induction motor by variable frequency control variable frequency control is a method which is used to control the speed of an induction motor. On a variable frequency drive vfd, the current is controlled by the power electronics. A better understanding of vfds will lead to improved application and selection of both. It is based on freescales 56f800e microcontrollers.

Variable voltage variable frequency speed control of. Aug 08, 2014 induction motor is constant speed motor at a particular frequency and consumes almost same power irrespective of load demand. Speed control of three phase induction motor ppt play ppt. You must use a simple ac transformer and a 393 comparator to get a zerocrossing time reference for the pwm interval to start. The internal circuit diagram of a typical vfd is as shown in fig.

Pdf performance analysis of threephase induction motor with. The pic16f7x7 series of microcontrollers have three onchip hardware pwm modules, making them suitable for 3phase motor control applications. Pdf experimental results of variable frequency drive for three. Here in venezuela there a long use of this vfd on heavy oil production, because this key feature which permits control of the oil extraction rate that is very important to. A dahlander motor also known as a pole changing motor, dual or two speed motor is a type of multispeed induction motor, in which the velocity of the motor is diverse by altering the number of poles. Variable frequency drive vfd to a motor driven system can offer potential energy. The synchronous speed of an induction motor is given by the relation shown below. Speed control of single phase ac induction motor possible.

Ac drive parameter access in a tabbed dialog format. The different methods of speed control of induction motor can be broadly classified in to scalar and vector control methods. Pdf modeling and speed control of induction motor drives. Variable voltage variable frequency control of threephase induction motor in closed loop is the significant feature of the thesis work. The synchronous speed and therefore, the speed of the motor can be controlled by varying the supply frequency. Speed control of a three phase induction motor using pwm inverter. There are more than one methods to control the speed of induction motor, you can choose one depending on your resources, efficiency required etc. Sep 01, 2016 an induction motor sees inrush current during a line start. The operating instructions are intended for use by competent personnel. The short answer would be to use a separate chip to perform the abcdq0 transformations and drive the ibgts.

For vfd operation with an unusually high starting torque, it is generally better to select a standard motor of the next larger size. In the first part of our presentation, we are going to discuss. Hence, it initiates a need to control various parameters of induction motor in order to run it properly and efficiently. As a result of using vfd, large amount of energy is saved by reducing sudden jerks at the start of the motor.