Variable Frequency Drive Ppt 38643e
This document was ed by and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this report form. Report 3b7i
Overview 3e4r5l
& View Variable Frequency Drive Ppt as PDF for free.
More details w3441
- Words: 808
- Pages: 26
VARIABLE FREQUENCY DRIVES Submitted by T.VANI SANTHOSHI – 09W91A0252 CH.ASHWINI - 09W91A0217 V.PRIYANKA GOUD – 09W91A0256 D.BASAVESHWAR – 07W91A0208 E.RAVI RAJA - 08W91A0239
Under the guidance of M.Spandana,M.tech Asst.Prof, EEE department Malla Reddy Institute of Engineering and Technology
INTRODUCTION A variable-frequency drive (VFD) is a type
of adjustable-speed drive
It is used in electro-mechanical drive systems to control AC motor speed and torque by varying motor input frequency and voltage.
ELECTRICAL DRIVES •
Systems employed for motion
control are called drives and may employ any of the prime movers such as diesel or petrol engines ,electric motors, for supplying mechanical energy for motion control . •
Drives employing electrical motors are known as electrical drives.
TYPES OF ELECTRICAL DRIVES There are two types of electrical drives mainly 1. 2.
•
•
DC Drives AC Drives DC drives are dc motor control systems AC drives are AC motor speed control systems
What is a VFD
It controls the rotational speed of an AC motor by controlling the frequency of electrical power supplied to motor.
It’s a specific type of adjustable speed drive
EVOLUTION OF VFD Danfoss = First company to mass produce a.c. variable frequency drives (VFD)
1968
1973
1983
1988
1993
1998
2003
2007
DESCRIPTION OF VFD A variable frequency drive generally consists of following:
Ac motor
Main controller assembly
Operator interface
AC MOTOR
It is usually a 3 – phase induction motor.
An AC motor is an electric motor driven by an alternating current.
The magnetic field on the rotor is either generated by current delivered through slip rings or by a permanent magnet.
MAIN CONTROLLER ASSEMBLY It is a solid state power electronic conversion device. It consists of three main parts
Bridge rectifier
DC link
Inverter
BRIDGE CONTROLLED RECTIFIER
It converts AC input power to DC intermediate power using a rectifier or converter.
DC LINK
DC intermediate power is then converted to quasi sinusoidal AC power using inverter switching circuit
BASIC INVERTER
It changes DC energy into three channels of AC energy that can be used by AC motor
OPERATOR INTERFACE
The operator interface often includes an alphanumeric display and/or indication lights and meters to provide information about the operation of the drive. A serial communications port is also often available to allow the VFD to be configured, adjusted, monitored and controlled using a computer
WORKING OF VFD
CIRCUIT DIAGRAM OF VFD
BLOCK DIAGRAM OF VFD
AC motor characteristics require the applied voltage to be proportionally adjusted whenever frequency is changed in order to deliver the rated torque
METHODS OF CONTROL
There are many methods of control for frequency in variable frequency drives
Among them PWM is mostly used because of its own advantages.
PULSE WIDTH MODULATION
Pulse-width modulation (PWM), or pulse-duration modulation (PDM), is a commonly used technique for controlling power to inertial electrical devices, made practical by modern electronic power switches.
TYPES OF VFD
VFD’s use their output devices (IGBTs, Transistors, thyristors) only as switches.
They can be classified as
Voltage source inverter fed drives i.e. constant voltage
Current source inverter fed drives i.e. constant current
CONSTANT CURRENT AND VOLTAGES DRIVES Constant voltage converter : intermediate DC link voltage remains constant during each output cycle •
Constant current drives : large inductor is placed between the input rectifier and the output bridge, so the current delivered is nearly constant •
FACTORS AFFECTING SPEED CONTROL
Cooling of the motor is usually not good in low speed range
.
When frequency reaches zero, motor is shut off.
The motor shall require a load reactor and filters if the pump leads from the VFD exceed certain conditions
ENERGY SAVINGS Example : vfd for centrifugal pump Flow is proportional to speed Power varies to the cube of the speed change 20% reduction in speed = 50% reduction in energy
50% reduction in speed = 80% reduction in energy
VFD RATINGS
VFD controllers designed to operate at 111v volts to 690v are often classified as low voltage units.
Typically designed for use with motor rated to deliver 0.2 k.watts up to several mega watts.
Medium voltage VFD controllers are designed to operate at 2400/4162 volts (60hz), 3000 volts(50 hz )
APPLICATIONS •
VFDs are frequently used to control motors for: Fans, Pumps, Compressors
Mills. •
Oil & Gas, petroleum, petro chemistry: oil transfer pumps, compressors, pumps, etc.
•
Mining: mortar pumps, fans, etc.
•
Water and waste water: water supply pump, etc.
CONCLUSION Hence variable frequency drives are mainly used because of the following reasons: •
Stable and reliable performance
•
Saves energy and therefore reduces energy costs
•
Isolated control signal provided by fibre optics between Power cell and Controller
QUERIES ???
THANK YOU
Under the guidance of M.Spandana,M.tech Asst.Prof, EEE department Malla Reddy Institute of Engineering and Technology
INTRODUCTION A variable-frequency drive (VFD) is a type
of adjustable-speed drive
It is used in electro-mechanical drive systems to control AC motor speed and torque by varying motor input frequency and voltage.
ELECTRICAL DRIVES •
Systems employed for motion
control are called drives and may employ any of the prime movers such as diesel or petrol engines ,electric motors, for supplying mechanical energy for motion control . •
Drives employing electrical motors are known as electrical drives.
TYPES OF ELECTRICAL DRIVES There are two types of electrical drives mainly 1. 2.
•
•
DC Drives AC Drives DC drives are dc motor control systems AC drives are AC motor speed control systems
What is a VFD
It controls the rotational speed of an AC motor by controlling the frequency of electrical power supplied to motor.
It’s a specific type of adjustable speed drive
EVOLUTION OF VFD Danfoss = First company to mass produce a.c. variable frequency drives (VFD)
1968
1973
1983
1988
1993
1998
2003
2007
DESCRIPTION OF VFD A variable frequency drive generally consists of following:
Ac motor
Main controller assembly
Operator interface
AC MOTOR
It is usually a 3 – phase induction motor.
An AC motor is an electric motor driven by an alternating current.
The magnetic field on the rotor is either generated by current delivered through slip rings or by a permanent magnet.
MAIN CONTROLLER ASSEMBLY It is a solid state power electronic conversion device. It consists of three main parts
Bridge rectifier
DC link
Inverter
BRIDGE CONTROLLED RECTIFIER
It converts AC input power to DC intermediate power using a rectifier or converter.
DC LINK
DC intermediate power is then converted to quasi sinusoidal AC power using inverter switching circuit
BASIC INVERTER
It changes DC energy into three channels of AC energy that can be used by AC motor
OPERATOR INTERFACE
The operator interface often includes an alphanumeric display and/or indication lights and meters to provide information about the operation of the drive. A serial communications port is also often available to allow the VFD to be configured, adjusted, monitored and controlled using a computer
WORKING OF VFD
CIRCUIT DIAGRAM OF VFD
BLOCK DIAGRAM OF VFD
AC motor characteristics require the applied voltage to be proportionally adjusted whenever frequency is changed in order to deliver the rated torque
METHODS OF CONTROL
There are many methods of control for frequency in variable frequency drives
Among them PWM is mostly used because of its own advantages.
PULSE WIDTH MODULATION
Pulse-width modulation (PWM), or pulse-duration modulation (PDM), is a commonly used technique for controlling power to inertial electrical devices, made practical by modern electronic power switches.
TYPES OF VFD
VFD’s use their output devices (IGBTs, Transistors, thyristors) only as switches.
They can be classified as
Voltage source inverter fed drives i.e. constant voltage
Current source inverter fed drives i.e. constant current
CONSTANT CURRENT AND VOLTAGES DRIVES Constant voltage converter : intermediate DC link voltage remains constant during each output cycle •
Constant current drives : large inductor is placed between the input rectifier and the output bridge, so the current delivered is nearly constant •
FACTORS AFFECTING SPEED CONTROL
Cooling of the motor is usually not good in low speed range
.
When frequency reaches zero, motor is shut off.
The motor shall require a load reactor and filters if the pump leads from the VFD exceed certain conditions
ENERGY SAVINGS Example : vfd for centrifugal pump Flow is proportional to speed Power varies to the cube of the speed change 20% reduction in speed = 50% reduction in energy
50% reduction in speed = 80% reduction in energy
VFD RATINGS
VFD controllers designed to operate at 111v volts to 690v are often classified as low voltage units.
Typically designed for use with motor rated to deliver 0.2 k.watts up to several mega watts.
Medium voltage VFD controllers are designed to operate at 2400/4162 volts (60hz), 3000 volts(50 hz )
APPLICATIONS •
VFDs are frequently used to control motors for: Fans, Pumps, Compressors
Mills. •
Oil & Gas, petroleum, petro chemistry: oil transfer pumps, compressors, pumps, etc.
•
Mining: mortar pumps, fans, etc.
•
Water and waste water: water supply pump, etc.
CONCLUSION Hence variable frequency drives are mainly used because of the following reasons: •
Stable and reliable performance
•
Saves energy and therefore reduces energy costs
•
Isolated control signal provided by fibre optics between Power cell and Controller
QUERIES ???
THANK YOU
Related Documents 3m3m1z
Variable Frequency Drive Ppt 38643e
November 2019 57
127335665 Variable Frequency Drive Ppt 4z2f33
December 2019 40
Variable Frequency Drive Basics 5y3f51
May 2020 14
Veichi - Variable Frequency Drive Manufacturer 6nl1x
March 2021 0
Variable Frequency Transformer Ppt 5z3k64
December 2019 68