Notch filter for control signals in PWM controlled systems

摘要

A notch filter includes first, second, and third difference modules, a delay module, and a gain module. The first difference module calculates a first difference between a control signal in a pulse width modulation (PWM) system and a feedback value. The second difference module calculates a second difference between the first difference and a delayed second difference. The delay module generates the delayed second difference by introducing a one period delay to the second difference, wherein the period is based on a Nyquist frequency of the control signal. The gain module generates the feedback value by applying a gain to the delayed second difference. The third difference module generates a filtered control signal by calculating a difference between the signal and the feedback value, wherein the filtered control signal is used to control an operating parameter of the PWM system.

主权项

1. A notch filter comprising:
a first difference module that calculates a first difference between a control signal in a pulse width modulation (PWM) system and a feedback value; a second difference module that calculates a second difference between the first difference and a delayed second difference; a delay module that generates the delayed second difference by introducing a one period delay to the second difference, wherein the period is based on a Nyquist frequency of the control signal; a gain module that generates the feedback value by applying a gain to the delayed second difference; and a third difference module that generates a filtered control signal by calculating a difference between the signal and the feedback value, wherein the filtered control signal is used to control an operating parameter of the PWM system.