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How does an ac drive variable speed drive operate to control speed?
Wiki User
∙ 13y ago
Answer #1
It varies the frequency fed to a synchronous AC motor. As the frequency changes, so does the motor speed.
Answer #2
The formula for calculating speed is:
(120 X motor supply frequency) / number of poles
120 is a fixed number, so is the number of poles for a given motor, hence the only variable is the motor supply frequency. AC drives vary the motor supply frequency in turn achieving speed control.
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∙ 13y ago
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What is the function of vfd?
It is a variable frequency drive, used to control the speed of a 3-phase motor all the way from stopped to full speed, and anywhere in between. Also called VSD, for variable speed drive, they are used to control pumps, fans, conveyor belt drives, anywhere a motor needs to be controlled to a precise speed other than the normal nameplate full speed, or where the speed needs to change to meet different operating conditions.
What does an AC drive do and what is it used in?
A variable-frequency drive (VFD) or adjustable-frequency drive (AFD), variable-voltage/variable-frequency (VVVF) drive, variable speed drive (VSD), AC drive, micro drive or inverter drive is a type of motor drive used in electro-mechanical drive systems to control AC motor speed and torque by varying motor input frequency and voltage. Wuxi JACT Electric Co,High quality frequency AC drive, 1、Advanced vector motor control algorithm，high performance and high precision motor control;open loop V/F & SVC control，closed loop FVC control. 2、The low-frequency large-torque: 150% at 0.5 Hz for SVC;180% at 0 Hz for FVC. 3、Wide power design (0.7kW-710kW) and support various motor configurations, Support a variety of encoders, can achieve high-precision closed-loop control. 4、It integrates speed control, torque control and position control, and can be widely used in synchronous and asynchronous motor control. 5、Independent air duct design, long life and large air volume cooling fan to improve the cooling efficiency of the inverter and ensure the stable operation of the inverter.
What method can be used to control the speed of rotation of a 3 phase induction motor?
USE VARIABLE SPEED DRIVE (VSD) OR ALSO CALLED VARIABLE FREQUENCY DRIVE (VFD). THE PRINCIPLE IS TO VARY OR CHANGE THE FREQUENCY WITHOUT AFFECTING THE VOLTAGE. THIS IS ONE SOLUTION TO ENERGY MANAGEMENT AND COMBINED TO BUILDING AUTOMATION SYSTEM OR BUILDING MANAGEMENT SYSTEM.
Describe why variable speed compressor motors are more efficient than single speed motors in heat pump systems?
This type of compressor uses a special drive to control The speed of the unit. Also, saves more energy than a fixed speed equivalent.
What in slip speed control?
slip speed control refers to induction machines s=(synchronous speed-motor speed)/synchronous speed by varying slip the machine can be either be operate in generated mode or motor mode
What's the difference between a variable frequency drive (VFD) and a variable speed drive (VSD)?
Adjustable speed drive (ASD) or variable-speed drive (VSD) describes equipment used to control the speed of machinery. Many industrial processes such as assembly lines must operate at different speeds for different products. Where process conditions demand adjustment of flow from a pump or fan, varying the speed of the drive may save energy compared with other techniques for flow control
How do variable speed motors work?
A variable sped drive is sometimes also known as a variable frequency drive. These drives are used in electro-mechanical drive systems to control AC motor speed and torque.
Speed control of a.c motor?
Use a variable Frequency Drive. Sold by ABB, Allen-Bradley, and many others.
Why shaft generator can not operate in parallel with auxiliary generator?
Normal shaft generators do not have droop-control for frequency and voltage. Semiconductor (drive) based variable speed shaft generators may have those today.
Electronic component used to control speed of a motor?
In industrial, there is a device called variable frequency drive (allso frequency inverter, ac drive) to control the motor speed by adjusting output frequency.
Explain Speed mode torque mode in variable speed drives in detail?
Torque mode in variable speed drives is where the drive adjusts its torque according to the input. The speed/velocity mode is where the input is used to control the motor's RPM.
What is the difference between Variable Speed Drive and Variable Frequency Drive?
A variable frequency drive (VFD) refers to AC drives only and a variable speed drive (VSD) refers to either AC Drives or DC Drives. VFD's vary the speed of an AC motor by varying the frequency to the motor. VSD's referring to DC motors vary the speed by varying the voltage to the motor.
What is the function of vfd?
It is a variable frequency drive, used to control the speed of a 3-phase motor all the way from stopped to full speed, and anywhere in between. Also called VSD, for variable speed drive, they are used to control pumps, fans, conveyor belt drives, anywhere a motor needs to be controlled to a precise speed other than the normal nameplate full speed, or where the speed needs to change to meet different operating conditions.
What is the energy savings of an electric motor when reducing the speed with a variable frequency drive?
definitly it give more efficient than variable stator voltage.............but in variable frequency ...............the frequency is not only variable....it is E/F control.because to maintain constant flux......... USUALLY THIS SPEED CONTROL IS ODOPTING IN INDUSTRIES......
why we use variable speed drivers in motor control units?
Variable speed drivers are necessary to be able to have different speed settings in a motor.
What is VFD in electrical engineering?
it stands for Variable Frequency Drive. It uses either a local controller or an input signal to control the frequency or speed of a motor.
How do you operate a vfd?
VFD is an adjustable speed drive that is used mostly in electro mechanical drive systems that control AC motor speed. VFD has come down on cost and the size which improved performance through advance in switching devices.
