A variablefrequency drive is a device used in a drive system consisting of the following three main subsystems. Variable speed drives for food and beverage production english mp4 movie abb acs480 and acs580 general purpose drives. In most control systems the structure and parameters are taken into account to make it possible for precise control of the motor. For an additional 9 years he was a principal advisor to. In hvac systems, they are used primarily to control fans in variable air volume systems instead of other devices such as inlet vanes and discharge dampers. 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. The total efficiency of the drive system depends on the losses in the motor and its control. Variable speed browning offers one of the worlds most complete selections of instock variable speed drives, including variable pitch sheaves through 750 hp.
Adjustable speed drive asd, also known as variablespeed drive vsd, describes equipment used to control the speed of machinery. The most common centrifugal load applications that use vfds are pumps, fans, and compressors. The ac electric motor used in a vfd system is usually a threephase induction motor. Hydraulic variable speed drives have fairly specific uses, for example, in the automatic transmission system of motor cars. Complete the application in full and return it to midamerican energy. Variable frequency drive vfd can be used in lots of fields. Basic theory of ac motors and drives, drive components, drive controls and communication, system alarms and maintenance. Guide to variable speed drives describes basics of different variable speed drives vsd and how they are used in industrial processes. Ac variable speed drives mv3000 course description. Special attention has been given to electrical vsds and especially to ac drives. Variable frequency drives are typically 9298% efficient with 28% losses being due to additional heat dissipation caused by the highfrequency electrical switching and the additional power required by the electronic components. Instead, they relate to the integration of these devices into the drive system. Some industrial machines will be more efficient if driven by a variable speed drive pumps, blowers, fans, etc. Variable speed drives vsds, also called adjustable speed drives asds, are devices that can vary the speed of a normally fixed speed motor.
A variable frequency drives used in a drivesystem consisting of the following three mainsubsystems. Variable speed drives altivar 61 and altivar 61 plus for asynchronous motors from 0. A 50% drop in speed produces almost an 88% reduction in power required to turn the load. Vfds may be referred to by a variety of other names, such as variable speed drives, adjustable speed drives, or. This guide does not cover other variable speed drives. Variable frequency drives are extremely versatile and offer a high degree of motor control where motor speeds can be accurately varied from zero rpm through over 100% of the rated speed, whilst the torque is also adjusted to suit. Variable speed ac drives with inverter output filters. Variable speed vbelts a variable speed vbelt is a wider, allowing for a greater range of speeds and better resistance to twisting while transitioning from one speed to another. In some applications such as speed control for a conveyor, the. It includes an introduction to drives, which may be informative to first time users. Huge energy savings potential operating centrifugal fans, pumps and compressors vary frequency of electrical.
These easytouse drives are wellsuited for variable torque applications like simple, standalone centrifugal fans and pumps. Vfd drives are also called variable speed drives, adjustable speed drives, electric motor speed controllers, and inverters. A variable speed drive is an electronic device which changes the speed of a motor by changing the frequency and voltage fed to the motor. Ac motor, main drive controller assembly, and driveoperator interface 210211 ac motor. Variable frequency drive applications variable speed drives. Included are the latest developments in this rapidly changing. Drives are becoming cheaper use of a variable speed drive can result in both an improvement in system performance and reduce energy demand much of this course concentrates on ac drives, in particular induction machine drives and a also drives for. Most vfd drives for dummies integrate a solid state electronics controller consisting of a bridge rectifier, a converter, and an inverter module. An ac motor runs at a speed proportional to the frequency applied, as described in the following formula. These versatile and robust devices are the prime movers for the vast majority of machines.
Paul guyer is a registered mechanical engineer, civil engineer, fire protection engineer and architect with over 35 years experience in the design of buildings and related infrastructure. Dc motor principle a machine that converts dc power into mechanical energy is known as dc motor. Vsd increase efficiency by allowing motors to be operated at the ideal speed for every load condition. Energy savings using a vfd to control the speed of a variable torque load can be very large due to how centrifugal loads operate. After the power flows through the rectifiers it is stored on a dc bus. A vfd therefore provides continuous range process speed control as compared to the discrete speed control that gearboxes or multispeed motors provide. Where process conditions demand adjustment of flow from a pump or fan, varying the speed of the drive may save energy compared with. Many industrial processes such as assembly lines must operate at different speeds for different products. Variable frequency drive technology is now mature and enjoying widespread adoption and use with ac motors. Early electric vsds consisted of ac and dc motors combinations which were used as rotating controllers.
Horsepower increases or decreases as cubic function of speed. Variable speed drives 252 mv3000 variable frequency drives theory course description. 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. The first electronic controllers used thyristor scr rectifiers which controlled the voltage, and therefore the speed of dc motors. Siemens standard drives application handbook siemens industry. The speed of the rotating magnetic field can be determined as. This book provides an authoritative, yet practical guide for the engineer or technician involved in specifying, applying, maintaining or operating variable frequency drives vfds. All parameters are program mable via a removable keypad that will. Its operation is based on the principle that when a current carrying conductor is placed in a. A variablefrequency drive vfd or adjustablefrequency drive afd. Introduction to sludge handling, treatment and disposal. Driveconfig the driveconfig kit is a new drive configuration tool for abb component drives, acs55, offering fast and safe configuration of unpowered drives. Variable frequency drives vfds popular speed control devices used in industrial, commercial and residential applications. Variable speed drives 3 why we need variable speed drives some industrial process need variable speed drives robots, machine tools, conveyors, etc.
High resolution english mp4 movie 7 technical guide, dimensioning of a drive system english pdf technical publication. This type of vbelt is recommended for variablespeed sheave drives that need to control speed to achieve a certain result. Ability to perform maintenance, identify faults units and replace with onboard spares. This manual is intended to help users of variable speed drives successfully install. Configuring energy optimizer function with drivetune. The use of vfds significantly reduces overall system maintenance.
In theory, these vfds differ primarily in the type of rectification by which they convert ac power to dc power. Variable frequency drives applied to ac motors are by far the most common. A variable speed drive vsd consists of a motor and some form of controller. A vfd converts the 5060hz fixedfrequency and fixedvoltage. New technologies and designs within these drives have made adding vsds a reliable and cost effective. The dc bus contains capacitors to accept power from the. Bearing currents in modern ac drive systems explains how to avoid damages. Guide to harmonics with ac drives describes harmonic distortion, its sources and effect, and also distortion calculation. Vbelts drives types, characteristic and industrial. Variable speed drive technology and the importance of controlling the speed of existing motors have fascinated many attentions in the last years with the advent of new power devices and magnetic materials. Ac power supply into a dc supply, using an integrated rectifier. Dave visits rockwell automation to learn about vsd drives. Motor data ratings are referred to as the power of the motor in kw and the full load current flc. Both drive and motor losses are ther mal, so they appear as heat.
Variable speed drives vsd or variable frequency drives vfd is electronic motor speed controllers that allow the speed rpm of any threephase electric motor to be varied from 0 to 120% of normal rated rpm. Exercises utilizing drive control and motor mockup equipment will. For final applications, submit product specifications. Some types of singlephase motors or synchronous motors can be. The vfd is by far the most common type of asd hardware. The benefits of variable speed drives also known as variable frequency drives as the cost of electric power continues to increase, variable adjustable speed drives vsds are becoming more popular in the car wash industry. These drives offer a motor current up to 720 a, for synchronous or induction motors.
In theory, a single vfd has the capability to control multiple motors. The ratio of static to friction head over the operating range influences the benefits achievable from variable speed drives see section 3. A key focus of variable speed ac drives with inverter output filters is to examine the state variables estimation and motor control structures which have to be modified according to the used solution filter. Our powerflex 6000 drives meet applications that require variable speed motor control from 2. For prenotification include an itemized quote, product specifications and estimated installation date. Refer to user manual gs1m for additional specific wiring information. Variable frequency drive, operation and application of variable. Variable speed drives eaton offer a wide range of afd products to meet a wide array of applications from simple variable torque to more complex industrial applications such as conveyors, mixers and machine controls, all series offer a. In variablespeed applications, a dc motor may be operating in one or more modes. Variable frequency drive types there are three different vfd design types presently on the market.
Other types of variable speed control do not afford this possibility. Refer to the technical manual for the individual machine for. Dc motors although ac motors are used in most of the cases, dc motors have many applications and used for multipurpose applications. Variable frequency drives ressources naturelles canada. Scurve, overvoltage stall prevention, dc braking, fault records, adjustable car. With vfd speed control on a centrifugal fan or pump motor, energy use follows the affinity laws, which state that the motor electricity demand is a cubic relationship to speed under ideal conditions. Drivepm drive parameter manager is a pc tool for creating and editing parameter sets of variable speed drives to be suitable for flashdrop unit. The benefits of variable speed drives aerodry systems. What links here related changes upload file special pages permanent link page.
Applications of variable speed drive vsd in electrical. It includes full coverage of both ac and dc motors and controls. Mechanical, electrical, and fluid power adjustable speed drives are available that offer some of the. Courses are tailored to cover the actual components used on a specific drives system cdc, pece etc. Drives 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 175 pages electricians technical reference sep 1, 2000 download pdf file variable frequency drives handbook, volume 1 pdf download. Variable frequency drive basics theory variable speed drives. There are many different designs including hydrostatic drives, hydrodynamic drives and hydroviscous drives. Variable speed drives in electrical energy management. Project engineering of variablespeed drives often gives rise to questions that are not directly related to the actual tasks of a frequency converter. This paper provides a general overview of the use and application of variable speed drives in lift systems, discussing both current systems and recent advances in this area. This course covers vessel electric propulsion drive systems in use in the offshore industry. The most common constant torque load applications using vfds are positive displacement pumps, gear pumps, reciprocating pumps, conveyors, extruders, extruder knifecutters, mixers, and. Newly revised and edited and written in sttraightforward user language. An introduction to sludge handling, treatment and disposal j.
Advanced information is shown in italics, and may be skipped on first reading. The smaller physical size and lower initial cost of a vfd system are additional advantages. A vfd is capable of adjusting both the speed and torque of an induction motor. Variable speed drives fitted on a primary feed pump and product transfer pump in a refinery. Variable speed drives an overview sciencedirect topics. This manual is intended to help users of variable speed drives successfully install and utilise siemens standard drives. Variable speed drives program offers rebates for the installation of variable speed drive equipment.
1108 271 903 653 1383 1515 801 182 1551 1559 578 183 667 896 425 983 889 1568 780 1166 1034 1134 578 421 1585 1086 1060 1488 74 1293 101 1317 254 990 838 1293 733 994 560 706 1436 969 955