How does pulse width modulation work?

As its name suggests, pulse width modulation speed control works by driving the motor with a series of “ON-OFF” pulses and varying the duty cycle, the fraction of time that the output voltage is “ON” compared to when it is “OFF”, of the pulses while keeping the frequency constant.

What is pulse width modulation control of a converter?

Pulse Width Modulation (PWM) is a control technique used in power electronics converter to regulate power supplied from power source to load. Duty cycle is the output variable of PWM which carries information and encode the control function of converter [1- 2].

What is pulse width modulation and how is it generated?

Pulse Width Modulation (PWM) is a technique to generate low frequency output signals from high frequency pulses. Rapidly switching the output voltage of an inverter leg between the upper and lower DC rail voltages, the low frequency output can be thought of as the average of voltage over a switching period.

What is a DC bus in a VFD?

Dc bus: The second primary section of a VFD’s main power circuit, chiefly comprised of capacitors that store power rectified by the converter. 3. Inverter: The third and final primary section of a VFD’s main power circuit.

How is DC bus voltage calculated?

The dc bus voltage is relative to the peak voltage of the mains input. What to look for: dc bus voltage is ~1.414 x the rms line voltage (e.g., for a 480V ac drive, the dc bus should be ~678V dc. A dc voltage value that is too low can cause the drive to trip.

What is pulse modulation system state and prove the sampling theorem?

The sampling theorem states that, “a signal can be exactly reproduced if it is sampled at the rate fs which is greater than or equal to twice the maximum frequency W.” To put it in simpler words, for the effective reproduction of the original signal, the sampling rate should be twice the highest frequency.