What is VFD and its function?
A variable frequency drive (VFD) is a type of motor controller that drives an electric motor by varying the frequency and voltage of its power supply. The VFD also has the capacity to control ramp-up and ramp-down of the motor during start or stop, respectively.
What is the basic principle of operation of variable speed AC drives?
A vsd, also referred to as a variable-frequency drive (vfd) or adjustable-speed drive (asd), is a power-conversion device that varies the speed of a three-phase induction motor. The basic principle used by the vsd is to vary the frequency of its output, which, in turn, varies the speed of the motor.
How does a VFD control voltage?
VFDs rectify a three-phase input to a fixed dc voltage that is filtered and stored using dc bus capacitors. Output frequency increases and output voltage should increase at the same rate, which keeps the motor flux constant. The resulting voltage waveform that is applied to the motor winding is not sinusoidal.
What is the working principle of a VFD?
– VFD working principle. In comparison, a VFD delivers a varying voltage and frequency to the motor, which determines its speed. The higher the frequency sup plied to the motor, the faster it will run. Power applied to the motor through the VFD can make the motor working speed lower than the nameplate base speed,…
How does a VFD control the speed of a motor?
As applications become more complex the VFD has the ability to control the speed of the motor, the direction the motor shaft is turning, the torque the motor provides to a load and any other motor parameter that can be sensed.
Can a VFD be used for a sinusoidal output?
VFD’s do not produce a sinusoidal output. This rectangular waveform would not be a good choice for a general purpose distribution system, but is perfectly adequate for a motor. If we want to reduce the motor frequency to 30 Hz, then we simply switch the inverter output transistors more slowly.
How does the VFD work in a microprocessor?
the microprocessor control section (CPU) and the control section that includes the external switches an signals to control the VFD operations the power section where AC voltage is converted to DC and then DC is inverted back to 3-phase AC voltage.