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its for something known as "time pass"
no good reason...just there
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How does the output voltage of the VFD change if the DC bus voltage level is fixed?
The VFD outputs pulses at the DC bus voltage. Each pulse is from the DC bus and the voltage does not change. It is the average voltage that changes because the VFD changes the on and off times of these pulses. For a lower average ac voltage to the motor, the ON time is small and the OFF time is large. The VFD actually pulses about 4000 times per second, so the motor does not really know these are just lots of quick DC bus voltage pulses. To simulate an ac waveform, the VFD uses pulse-width modulation which means the pulse ON time at the peak of the simulated sinewave is longer, or fatter, than the pulses where the simulated sinewave is closer to 0 crossing.
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.
Why dc series motors cannot be used in home?
DC series motors run on DC power. Homes have AC power, not DC power. You could use DC motors in homes if you have a power supply or use a battery, but it is usually more cost effective to use an AC motor.
Can you use dc motor to power hydro turbine?
no you can't use dc motor to power hydro turbine ?
How do you measure DC amp output from rectifier unit?
You can use a DC ammeter.
How do you install a timer to a VFD?
You can either use the inbuild timer in VFD or go with secondary timer or a controller like PLC. You may use the below link to learn more on VFD www-dot-smeclabs-dot-com
How does the output voltage of the VFD change if the DC bus voltage level is fixed?
The VFD outputs pulses at the DC bus voltage. Each pulse is from the DC bus and the voltage does not change. It is the average voltage that changes because the VFD changes the on and off times of these pulses. For a lower average ac voltage to the motor, the ON time is small and the OFF time is large. The VFD actually pulses about 4000 times per second, so the motor does not really know these are just lots of quick DC bus voltage pulses. To simulate an ac waveform, the VFD uses pulse-width modulation which means the pulse ON time at the peak of the simulated sinewave is longer, or fatter, than the pulses where the simulated sinewave is closer to 0 crossing.
Why vfd is used with fd fans?
Traditionally dampers are used to control the quantity of air entering the boiler. If we use VFD for FD fan, we can control the quantity of air be changing speed of fan using VFD. This will save energy.
How do vfd's change the AC to dc current and back into AC?
Variable frequency drives use a rectifier to "chop off" the top part of the ac wave, then use capacitors to "fill in" the gaps in the voltage, making a "near dc" power. They use IGBTs, a fancy term for a high speed, high current transistor, or electronic switch, to pulse the "near dc" power out to the motor, in a pattern that appears like ac to the motor.
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.
Speed of DC Motor can be controlled by a frequency variable?
by using a frequency tuner in input we can change input frequency and in this way speed of dc motor will also vary. <<>> Varying the frequency (VFD) only works on AC motors.
How do you decide whether the variable frequency drive is compatible with my DC motor or not?
Variable frequency Drive is not compatible with a DC Motor. VFD can be used only with AC motors, where frequency plays a key role in defining the speed of the motor.
Can someone suggest me tips regarding the use of 15 HP variable frequency drives?
Use the drive if you are in need of smooth start and stop. If your process needs speed variations with out manual intervention, then VFD is the best device to do it. Use it in combination with a PLC or so that the use of VFD can be maximized.
Did VFD exist?
Yes because VFD means Volunteer Fire Department and there are many characters in it
What to do to reduce the noise generated because of VFD or Motor?
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.
Is vfd real?
Yes
What brands of VFD's are you familiar with?
NO
