Noise characteristics of DC-AC random PWM inverters

Random PWM (RPWM) techniques normally work well with high sampling frequency. When implemented in digital signal processors (DSP), performance of the RPWM schemes are limited by the speed of the processors. In this paper, the noise spectra of various DSP implemented RPWM techniques are presented. The relationships of the noise components and the sampling frequency for both the standard RPWM and the weighted RPWM methods are given. The dependency of the noise characteristics on various factors is calculated theoretically and verified experimentally.