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If the motor is connected to a VFD the conductors of the motor need not be changed. The phase reversal can be done with the VFD's internal circuitry.
No. Use standard utility AC, 3 PH voltage to feed a Variable Frequency Drive (VFD). The VFD is then wired to the motor. The output of the VFD varies average voltage and frequency in a semi-constant proportion to keep Volts/Hertz ratio the same to the motor. The operator can then adjust or select the desired speed from the VFD and the VFD will run the motor continuosly at that desired speed. If you were to control only voltage to the motor without adjusting frequency in proportion, the motor would burn up.
To reduce the noise generated because of VFD harmonics, line filters have to be used on the line side and load side of the VFD. The specific filters suppress the harmonic frequencies that the VFD generates when the SCR's are rapidly turning off and on.
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.
VFD- variable frequency drive, is a power electronics device which control the motor speed. It is very famous in Industries for energy saving perpose.
VFD is shorted for variable frequency drive, it's a electric device to control AC motor speed by adjusting the frequency, it's a kinds of energy saving device, like in pump motor, injection molding machines. There are many manfacturers producing VFD such as Delta, Veichi, Siemens, Hitachi and etc.
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.
I like VFD control. A VFD varies the speed of the motor which therfore varies flow. A control valve simply restricts flow. Control valves usually need intrument air compressors and have lots of moving parts and things that need repair. VFD control has no moving parts and uses less energy when running at a reduced capacity.
One application of feed back control is where the speed of a motor has to be maintained at a certain RPM and the load it drives is variable. Feedback from the load tells the VFD (Variable Frequency Drive) motor controller what to do. As the load drags the motor speed down the feedback unit sends a electrical impulse to the VFD to increases the speed of the motor. As the load drops off the feedback unit sends a electrical impulse to the VFD to decreases the speed of the motor. These interactions keep the motor RPM at a constant speed. This is a very simplified version of what happens.
I have used several hundred ABB drives. The term "VFD" is just another name for a "drive". It stands for Variable Frequency Drive. A "VFD System" is an electrical power control system, for example running a pump, in which the drive varies the speed of the pump motor. The drive does this electronically using pulse-width modulation to vary the average motor power frequency. When the motor sees 30 Hz instead of 60Hz, the motor runs 50% speed.
400hp slipring motor has been short circuited and connected to the 315kw variable frequency drive. The vfd has run continuously for 2 days without any problem.After a supply break the vfd couldnot resume but indicating a message of impedence short.
set the respective parameter for torque in the VFD.