Analysis, design, and implementation of a random frequency PWMinverter

摘要

Random pulse width modulation (RPWM) approaches can make thenharmonic spectrum of inverter output voltage be continuously distributednwithout affecting the fundamental frequency component, and thus thenacoustic noise and mechanical vibration of an inverter-fed AC motorndrive are greatly reduced. However, the analysis and design of the RPWMnmechanisms are generally not so trivial for practical engineers thatntheir applications are limited. In this paper, a random frequency PWMn(RFPWM) inverter and its practical design procedure are presented.nFirst, the effects of the attributes of a random signal on the inverternoutput harmonic spectrum distribution characteristics are analyzed usingnan intuitive concept, then based on which, the quantitative design.nSimulink simulation and implementation of the proposed RFPWM inverternare introduced. The proposed RFPWM inverter is employed to power annindirect field-oriented induction motor drive. The simulated andnmeasured results indicate that the uniform random distribution ofninverter output harmonic spectrum and thus smaller acoustic noise andnmechanical vibration are obtained by the proposed RFPWM scheme