Vfd for ac motors have been the innovation that has brought the use of ac motors back into prominence. Construction, theory, and technical characteristics. A basic vfd system generally consists of an ac motor, a controller, and an operator interface. Without proper cooling a drive will shut down on overtemperature. In contrast, if the strength of the magnet is too strong the iron in the motor will become saturated, causing the motor to run hot and eventually fail. The most popular type is the 3phase, squirrelcage ac induction motor.
Basic vfd training houston abb basic 2 day vfd class cates. One economic benefit comes from the reduction of maintenance when using a vfd, especially not having to deal with the dc motor carbon brushes or mechanical speedcontrol gearboxes transmissions. Danfoss, abb, telemechanique, honeywelltrend, jaguar, hitachi, imo, control. As the frequency is decreased, the speed of the motor also decreases. In order to properly cover the subject, it will be broken into four distinct parts. One of the best vsd motor online courses you can get as it never expires, 247 access. Variablefrequency drive a variablefrequency drive vfd also termed disebut adjustablefrequency drive, variable speed drive, ac drive, micro drive or inverter drive is a type of adjustablespeed drive used in electromechanical drive systems to control ac motor speed and torque by varying motor input frequency and voltage. The most obvious reason to procure a vfd is speed control. With this electric drive tutorial youll learn how does a variable speed drive work vfd drive working principle, and other industrial drive essentials. This provides accurate control of the motor speed and also reduces energy consumption. Variable frequency drives vfd 101 this basic 12day introduction to variable frequency drives class is designed for those who need to use, implement or purchase vfds, and would like to learn more about what they are and how they work. Variable frequency drive, operation and application of variable.
It is not a good idea to use the powerswitch on the machine to shut down a motor that is run by a vfd it voltage spikes the vfd. Therefore, in the vfd, the voltage applied to the motor is also reduced with frequency to prevent the motor from being damaged by excessive current. Basic construction and operating principle like most motors, an ac induction motor has a fixed outer portion, called the stator and a rotor that spins inside with a carefully engineered air gap between. A variable frequency drive, as used for controlling motors, works on the principle of varying the applied voltage simultaneously with the frequency at a constant ratio. As an example, ac 480v, 60hz supply is applied to the vfd which varies the signal voltage and frequency to have control of the speed. In this paper the connection is made with the theory about vfd. Use features like bookmarks, note taking and highlighting while reading variable frequency drives.
What are some good vfd variable frequency drive books. A variablefrequency drive is a device used in a drive system consisting of the following three main subsystems. Ac motor, main drive controller assembly, and driveoperator interface 210211 ac motor. Huge energy savings potential operating centrifugal fans, pumps and compressors vary frequency of electrical supply to an induction motor to vary the motor speed. Most vfd drives for dummies integrate a solid state electronics controller consisting of a bridge rectifier, a converter, and an inverter module. Variable frequency drives vfd s popular speed control devices used in industrial, commercial and residential applications. Failure to comply may result in damage to the equipment. Electrical drives are integral part of industrial and automation processes, particularly where precise control of speed of the motor is the prime requirement. This vfd basics training software use the allen bradley vfd powerflex, the variable frequency drive basics taught can be applied to abb vfd, siemens vfd or any other brands vfd working principle. Variable frequency drive types there are three different vfd design types presently on the market. The term inverter also refers to a rectifierinverter group, powered by alternating current and used to vary the voltage and frequency of the output alternating current in function of the input voltage for example, for power supply. Programmable logic controllers, basic level textbook.
If the strength of the magnet is too weak the motor will become weak and will not be able to provide enough torque. Abb basic and advanced vfd training classes follow the same course syllabus. The variable frequency drive is correctly programmed to deliver the intended operation and energy savings and that this is demonstrated to operators engineering staff on completion. In theory, these vfds differ primarily in the type of rectification by which they convert ac power to dc power. The vfd controller panel is the heart of the application. How three phase motors work, how vfds work, and what types of applications are they used for. A variable speed drive vsd consists of a motor and some form of controller. One of these modules is used for each phase in a three phase drive.
This variable frequency drives electrical training course will cover. Basic refrigeration cycle a centrifugal chiller utilizes the vapor compression cycle to chill water and reject this heat collected from the chilled water plus the heat from the compressor to a water loop cooled by a cooling tower. This variable frequency drive basics, is a vfd basics industrial drive training online certificate course. Other names for a vfd are variable speed drive, adjustable speed drive, adjustable frequency drive, ac drive, microdrive, and inverter. Control method there are three basic methods to control a variable frequency drive. The inverters are also used in many other applications, ranging from ups to the speed controllers of electric motors, from switching power supply to lighting. Vfd was an independent group tasked with the research and creation of biological weapons, specifically fungi. This module presents the operation of a typical vfd. Every vfd hasits own component characteristics, so how each vfd works is dependent upon components within the vfd. Variable frequency drives vfd, aka variable speed drive vsd have been available for use with a wide range of applications for over 20. Brief explaination about working of vfds, benefits and. A variable frequency drive vfd is a type of motor controller that drives an electric motor by varying the frequency and voltage supplied to the electric motor.
It includes an introduction to drives, which may be. The voltage and current should lie within the range as indicated on the nameplate. The acinduction motor can have its speed changed by changing the frequency of the voltage used to power it. Vfds rated above 3 hp can be run on single phase input but their rated output is roughly halved. Home download center electrical engineering books and technical guides siemens basics of energy and automation guides the basics of ac drives totally integrated automation tia automation is a strategy developed by siemens that emphasizes the seamless integration of automation products. Variable frequency drives electrical training rutgers. To better understand this, lets take a look at some basic motor theory. A rectifier that converts the fixed frequency ac input voltage to dc. Variable frequency drives vfds control the speed of motors by varying the frequency of the supplied power. This variable frequency drive basics training software is interactive and has real world simulations. An inverter that switches the rectified dc voltage to an adjustable frequency ac output voltage. I know other people here have set up their own shop and some have bought good books along the way. The above figure shows how the voltage and frequency are varied by a variable frequency drive.
The new control system had to meet the following requirements. Simple programming program changes without system intervention. Aug 21, 2017 this elearning module provides a basic understanding of variable frequency drives. I would like to understand 3 phase a lot more than i do now. There are two basic types of losses, constant and variable, both of which. This manual is intended to help users of variable speed drives successfully install and utilise siemens standard drives. The first programmable logic controller plc was developed by a group of engineers at general motors in 1968, when the company were looking for an alternative to replace complex relay control systems. Certificates of completion will be awarded to those who pass the test on the second day. Become familiar with the basic principles of connection technology and circuit technology for the components used become familiar with the safe and correct way of commissioning a servo motor system become familiar with the basic principles of configuration and parameterisation of a servo motor system. Variable frequency drive vfd working principle instrumentation. The most common centrifugal load applications that use vfds are pumps, fans, and compressors. They all operate on the same basic variable frequency drive theory. Although much has been published on variablefrequency drives vfds, people continue to be confused by them.
Although vfds are highly efficient devices, manufacturers are. Thanks to the help of simple illustrated diagrams, you will be guided in understanding this important electronic device that is indispensable. Variable frequency drives vfds popular speed control devices used in industrial, commercial and residential applications. Download it once and read it on your kindle device, pc, phones or tablets. The ac electric motor used in a vfd system is usually a threephase induction motor. Part of the electricians technical reference series, this field guide is ideal for gaining access to information about variable frequency drives, including how. Basic working principle behind vfds variable frequency drives components of a drive. There are a lot of tradeoffs in the different designs and depending on the goals and preferences of the. The intent of this article is to provide a basic overview of these devices by evaluating key features as well as their impact on a buildings electrical system. In addition, all modern electric trains or locomotive systems have been powered by electrical drives. Mar 12, 2020 while most control circuits used in industrial or commercial applications still use mechanical operating systems, the application of vfd s is increasing as a way to reduce power consumption and other operating costs. A vfd is specifically designed and intended to do this to ensure a safe and an efficient method of speed control of an ac motor without affecting its current consumption. Vfd fundamentals copyright 2003 kilowatt classroom, llc.
Modules are a complete functional block that may include. Eu council directives and adjustable speed electrical power. Vfd is shorted for variable frequency drive also known as ac drives and inverters thats used to make an ac motor working in variable speed among other parameters. Some features may not be available on basic micromaster. This is usually done for process, operation, and economic benefits. Abb basic and advanced classes follow the same course syllabus. The variable frequency drive industry is growing rapidly, and it is now more important than ever for technicians and maintenance personnel to keep vfd installations running smoothly. In this presentation, we will be covering variable frequency drives vfd s and their theory, application, and troubleshooting. While most control circuits used in industrial or commercial applications still use mechanical operating systems, the application of vfds is increasing as a way to reduce power consumption and other operating costs. The author doesnt drone on about electrical theory he assumes you already have a solid. Energy is supplied to the process through the motor shaft. Abb vfd training dallas abb basic 2 day vfd class cates.
In this page we are going to explain what an inverter is, what is its function, what it is made of, what its principle of operation and what are the main types of inverters used in the most common situations and needs. Abb protection, control and electrical devices 7 1 standards 1. Operatorsengineering staff are trained in controlling and working of the variable frequency drive. These applications include single motor driven pumps, fans and compressors, as well as highly sophisticated multidrive machines. Vfd basics theory variable frequency drives vfd, aka variable speed drive vsd have been available for use with a wide range of applications for over 20 years.
Become familiar with the basic principles of connection technology and circuit technology for the components used become familiar with the safe and correct way of commissioning a servo motor system become familiar with the basic principles of configuration and. Ac motor, main drive controller assembly, and driveoperator interface 210211. Variable frequency drive basics, vfd training online. The vfd panel takes in a fixed voltage and frequency and gives out a variable voltage and frequency to the motor.
This is definition used in all topical discussion on this paper. Variable frequency drive basic components most variable frequency drives consist of three basic parts. 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. The basics of ac drives eep electrical engineering portal. In many commercial, industrial, and utility applications electric motors are used to transform electrical energy into mechanical energy.
Dec 23, 2005 im need some suggestions for good book that explains 3 phase for a home shop. Electrical installation handbook protection, control and. I will be getting trained on drive maintenance and i wanted to get some theory and basics down befor i start. Variable frequency drive vfd output module shown below is a typical medium voltage vfd transistorized output module. This includes that many of the possibilities of the vector variable frequency drive cannot be discovered without additional automation tools to deliver feedback to the vector variable frequency drive. These variablefrequency drives vfds accurately control the speed of standard ac induction or. Im need some suggestions for good book that explains 3 phase for a home shop. Eu council directives and adjustable speed electrical power drive systems is to give a straightforward explanation. Some types of singlephase motors or synchronous motors can be advantageous in some situations, but. Precharging speed torque characteristics of a drive. The first problem a vfd manufacturer needs to address is heat. Theyre the only real source, of understanding how these amazing inventions work.
772 798 240 863 662 1602 1070 395 591 944 1265 1574 307 991 750 1531 388 537 1271 755 665 645 1423 148 388 191 492 719 760 248 1023 491