Method and apparatus for reducing sampling related errors in a modulating waveform generator used with a PWM controller

摘要

A method and apparatus for use with a controller that samples a command frequency and provides modulating waveforms to a PWM inverter as a function of the sampled command frequency, the inverter also receiving a carrier signal having a carrier frequency, the method for reducing distortions in the modulating waveforms that result from sampling characteristics of the controller, the method comprising the steps of sampling the command frequency at a sampling frequency to generate a series of sampled signals, integrating the sampled signals to generate a phase angle, identifying a correction angle as a function of the sampling frequency, adding the correction angle to the phase angle to generate a corrected phase angle and using the corrected phase angle to generate the modulating waveforms to be provided to the PWM inverter.