Abb tailored solutions and services abb drives abb. These omnipresent devices come in many varieties, but generally fall. Ac drives are used to stepless speed control of squirrel cage induction motors mostly used in process plants due to its ruggedness and maintenance free long life. The voltage in a directcurrent circuit must be constant, or at least relatively constant, to keep the current flowing in a single direction. Ac motors basics of ac drives basics of control components basics of plcs basics of sensors general motion control motor control centers. Explain the concept of force, inertia, speed, and torque explain the.
Their purpose is to provide a means to control the speed, and in some cases also torque, or power, of ac motors. A modern ac drive power structure consists of three basic stages. This selfstudy curriculum includes courses on electricity, controls, ac motors, and power distribution products. Ac drives range overview 12 ac650 ac650 general purpose vhz drive 0. This project aims to compile a number of technical notes that clarify basic concepts in engineering. At the input side an ac drive resembles a dc drive in that an alternating current ac input is regulated to dc by scrs or a simple bridge rectifier. The basic configuration of a variable frequency drive is as follows. Understanding electronic motor drives machine design. From ac motor basics like speed control to the basics of ac motor controller.
In order to understand how an inverter works, it is necessary to understand how an induction motor works. Understanding these will help in solving many problems irrespective of the type of the drive. The difference in the horsepower requirements at a given speed between the vfd and any other type of variable speed control is that vfds afford greater energy savings. Ac and dc motor and drive glossary, which contains a listing of ac and dc drives and motor terms. Ac motor, main drive controller assembly, and driveoperator interface 210211 ac motor. A variablefrequency drive is a device used in a drive system consisting of the following three main subsystems. Adjustable frequency drives welcome to module 20, which is about adjustable frequency drives. The term simovert is used by siemens to identify a siemens motor inverter ac drive.
A better understanding of ac drives will lead to improved application and selection of both equipment and hvac systems. They, in turn, supply the armature and field of variablespeed dc motors. Thus, the voltage provided by a flashlight battery remains steady at about 1. Siemens standard drives application handbook siemens industry. In the case of riecor farming in south africa an attempt to resolve one problem actually solved it extremely well and, in addition, gave numerous side benefits that decreases costs, work and headaches while making the farmers job easier. See the basic principle with the singlephase ac as the simplest example. In industrial terms, ac drive is also called as variable frequency drive vfd, variable speed drive vsd, or adjustable speed drive asd. Introduction to the function and benefits of ac drives. Simoreg drives are designed for connection to a threephase ac supply. L explain the concept of force, inertia, speed, and torque l explain the difference between work and power l describe the construction of a squirrel cage ac motor l identify the nameplate information of an ac motor. Voltagesource inverter drives are the most common vfd drives for dummies.
Aug 21, 2017 this elearning module provides a basic understanding of variable frequency drives. Basic ac drives ac drives, inverters, and adjustable frequency drives are all terms that are used to refer to equipment designed to control the speed of an ac motor. The ac induction motor is simple, low cost, reliable and widely used throughout the world. Schematic representation of a sinusoidal voltage of magnitude e applied on a circuit with a resistive load r.
Ac drive usage has increased dramatically in hvac applications. Ac motor basics construction, principle of operation, tn characteristic etc. The classification of electrical drives can be done depending upon the various components of the drive system. A better understanding of vfds will lead to improved application and selection of both equipment and hvac systems. Ac and dc drive print set, which contains schematics of selected allenbradley drives. The ac signal will be rectified and converted to a dc signal. Types of ac drives in todays marketplace, there are 3 basic ac drive categories. An understanding of many of the concepts covered in basics of electricity is required for basics of ac drives. Such drives are still in use in a large number of industries. In volts per hertz technology, when the frequency of supply changes, the voltage applied to the motor is also changed by the same amount as the frequency. Basics of ac drives siemens the tia strategy incorporates a wide variety of automation products such as programmable controllers, computer numerical controls, human machine interfaces hmi, and drives which are easily connected via open protocol networks.
If you continue browsing the site, you agree to the use of cookies on this website. Directive in the users systems and installations when using ac drives. It is ironic that while most dc drives run on ac, most ac drives run on dc. Basics of electricity basics of electrical products. Basics of ac drives ebook pdf download siemens step course. Sensor open loop sensorless vector drives less vector. The positive end of the battery is always positive relative. Upon completion of basics of ac drives you should be able to. The ac electric motor used in a vfd system is usually a threephase induction motor. The differences between ac and dc drives global electronic. Powering industry since replacing the steam engine from tiny hysteresis motors that drive electric clocks to huge synchronous motors that develop more than 50,000 hp, the alternating current ac motor has become an indispensable part of everyday life. There are some applications that use common dc bus and solar.
Aug 31, 2016 from ac motor basics like speed control to the basics of ac motor controller. Early electric vsds consisted of ac and dc motors combinations which were. The schematics shows the resultant current i in phase with the voltage v. Parker ac drive products are sold, supported and serviced worldwide, with solutions from simple speed control to complex. Advantages of ac drives over other methods of motor control applications for ac drives ac drive theory load and braking considerations chapter 3 square d ac drive products this chapter covers the features and benefits of the altivar 16, 66, 56, and 18 ac drive. Fi lv ac drives maintenance basics, internet course g106e english pdf information fi acsm1 solution program composer handson training g192 english pdf information fi acs80067, wind turbine drive startup, maintenance and service training g167 english pdf information. Ac drives have the lowest starting current of any starter type. For instance, take a simple application of a fixedspeed motor driving a fan. Ac motor, main drive controller assembly, and driveoperator interface. These drives convert ac line input to ac inverter output. Ac drives receive ac power and convert it to an adjustable frequency, adjustable voltage output for.
Half controlled and fully controlled bridge circuits, different. The basics of ac drives eep electrical engineering portal. This course covers basics of ac drives and related products. Ac drive control speed of ac motor by varying output voltage and frequency through sophisticated microprocessor controlled electronics device. Ac drives are used to drive the ac motor especially three phase induction motors because these are predominant over other motors in most of the industries. A converter is a device to create the dc from the ac power supply. Siemens ac drives can easily communicate with other control devices such as programmable logic controllers plcs and personal computers pcs through the profibusdp communication system and other various protocols mechanical basics.
An adjustable frequency drive or af drive is a device used to convert three phase, 60hz input power into an adjustable frequency and voltage source. Guide to variable speed drives describes basics of different variable speed drives vsd and how they are used in industrial processes. Vfd fundamentals copyright 2003 kilowatt classroom, llc. Wikipedia typically, the power supply to the variable frequency controller will start out as 3phase ac power. Oct 15, 2016 chapter 2 ac drive fundamentals this chapter covers. Handson practice handson practice is a necessary part of learning and this course offers handson opportunities to perform fundamental. Bearing currents in modern ac drive systems explains how to avoid damages. Now according to the design, the drives can be classified into three types such as singlemotor drive, group motor drive and.
Explain the concept of force, inertia, speed, and torque explain the difference between work and power describe the construction of a squirrel cage ac motor. Guide to variable speed drives describes basics of different variable speed drives. Busway load centers molded case circuit breakers panelboards power monitoring and management with. Digital drives are different only in the manner in which these basic functions are achieved. Inverter drives an inverter is an electronic power unit for generating ac power. Seen here are outtakes from free online ac motor drive basics course referenced at. Some types of singlephase motors or synchronous motors can be advantageous. This dc output would be a half cycle according to ac input phase frequency so ac drives use a capacitor bank to stabilize and smooth this dc voltage. Simoreg drives can be selected for connection to 230, 400, 460, 575, 690, and 830 vac, making them suitable for global use. 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. In order to control the speed of an ac induction motor a more complex controller, usually called an inverter is required. Ac motor drives are used in many industrial and domestic application, such as in conveyer, lift, mixer, escalator etc. Basics of an ac drive with motor basics slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
A variable speed drive vsd consists of a motor and some form of controller. Basic course on acdc drives drbdt sitrain personal. Ac drives reduce thermal and mechanical stresses on motors and belts. In order to properly cover the subject, it will be broken into four distinct parts. Figure 1 is a schematic diagram of a typical voltage source ac drive power structure. Table of contents eep electrical engineering portal. Centrifugal fans, pumps, compressors as the speed of the device is slowed, the torque and power required to run the. Change ac frequency variable speed ac motor adjustable speed drives are known as inverters, variable frequency drives vfd, or adjustable speed drives asd. Ac drives with afe technology can meet even the most stringent harmonic standards and reduce backup generator sizing. An adjustable frequency drive is a device used to control the speed, torque, horsepower and direction of an ac motor. Seen here are outtakes from free online dc motor drive basics. The power control relatively complex and more expensive. Guide to harmonics with ac drives describes harmonic.
Some types of singlephase motors or synchronous motors can be advantageous in some situations, but. Ac variable speed drives have been around now for more than 30 years, and whilst the design has been significantly refined over the years and components improved, the basic power stage circuit design used remains the same. Typical adjustable frequency drives like the other modules in this series, this one presents small, manageable sections. Each part of a variable frequency drive has the following function. Variable frequency drive vfd usage has increased dramatically in hvac applications. All ac drives convert fixed voltage and frequency into variable voltage and frequency, to run 3phase induction motors. Of course, variable frequency drives vfds and ac motors are now offering an alternative to dc drives and motors, but there are many other applications where dc drives are extensively used including crane and hoists, elevators, spindle drives, winders, paper production machines, crushers, etc.
Depending on the certifying organization, these courses may be. Ac drives control acinduction motors and, like their dc counterparts, control speed, torque, and horsepower. Ac drives control ac induction motors and, like their dc counterparts, control speed, torque, and horsepower. The ac drives are now commonly applied to air handlers, pumps, chillers and tower fans. There are many types of ac drives, but this course focuses on low voltage less than vac ac drives used with threephase induction motors, the most common pairing used in. From dc motor basics like speed control to the basics of dc motor controller. Ac drives receive ac power and convert it to an adjustable. Classification of electrical drives or types of electrical. Drive basics before we can have a meaningful discussion on harmonics with respect to ac drives, first it is necessary to have a good understanding of the basic workings of a modern pwm ac drive, specifically how it draws power from the utility line. In this presentation, we will be covering variable frequency drives vfds and their theory, application, and troubleshooting.
Pwm ac drive, specifically how it draws power from the utility line. Introduction to ac drives this module, introduction to ac drives, is designed to familiarize the participant with ac motor theory, ac drive theory, square d. Direct torque control or dtc is the most advanced ac drive technology. Pdf variable voltage ac drive systems researchgate. Ac drive installation is as simple as connecting the power supply to the ac drive. The volts per hertz technology is the most economical and easiest method of speed control of induction motors. Lecture notes on power electronics veer surendra sai. The speed of the motor can be controlled by using some type of electronic drive equipment, referred to as variable or adjustable speed drives. Ac drives function by converting a constant ac frequency and voltage into a variable frequency and voltage. In this method, drive controls shaft speed by varying the voltage and frequency of the signal powering the motor. No part of this document may be stored in a retrieval system, or transmitted in any form or by any means to persons not employed by a parker hannifin manufacturing limited company without.
Lightweight 20% to 40% lighter than equivalent dc motor inexpensive low maintenance. Explain the concept of force, inertia, speed, and torque. You should complete basics of electricity before attempting basics of ac drives. Drives give south african farmer 40% energy savings. Table of contents series power range page introduction to parker hannifin 4 service and support 8 ac drives range overview 12 ac650 ac650 general purpose vhz drive 0. Energy savings traditionally used to justify installation. In many commercial, industrial, and utility applications electric motors are used to transform electrical energy into mechanical energy. The vfds are now commonly applied to air handlers, pumps, chillers and tower fans. An ac motor of this type may be part of a pump or fan or connected to some other form of mechanical equipment such as a winder, conveyor, or mixer.
Most vfd drives for dummies integrate a solid state electronics controller consisting of a bridge rectifier, a converter, and an inverter module. There are many types of ac drives, but this course focuses on low voltage less than vac ac drives used with threephase induction motors, the most common pairing used in industrial applications. Special attention has been given to electrical vsds and especially to ac drives. Introduction to ac drives this module, introduction to ac drives, is designed to familiarize the participant with ac motor theory, ac drive theory, square d ac drive products and their enclosures, and provide job aids.
1380 1385 378 552 707 1407 359 1658 1424 1451 234 444 1353 1213 959 849 1042 563 31 461 642 1219 962 1256 350 73 631 1273 771 939 1033 1463 1405