Noise analysis of DC-AC random PWM schemes

摘要

Random pulsewidth modulation (RPWM) techniques for DC-AC powernconverters usually work well with high-sampling frequency. When RPWMnschemes are implemented in digital signal processors (DSPs), thensampling frequency is limited by the speed of the processors. This papernanalyzes the noise spectrum of various DSP-implemented RPWM techniquesnusing a statistical approach. The relationship of the noise componentsnand the sampling frequency for both the standard RPWM and the weightednRPWM methods is generalized. The dependency of the noise characteristicsnon various factors is calculated theoretically and verifiednexperimentally. The generalized noise theory for randomized PWMnswitching provides useful practical guidelines to the choice of samplingnfrequency