Optimized Digital Implementation of Carrier-based Randomized Discontinuous PWM Technique for Active Front End(AFE) Drives

Pulse width modulation (PWM) technique and micro-processor have been extensively used in power electronics converters. Discontinuous pulse width modulation (DPWM) technique is proposed and applied in industrial drive application where switching loss is of great concern and critical to increasing converter’s power density. In addition, random modulation is gaining more interest because of its potential to alleviate the electromagnetic interference (EMI) problem incurred in power electronics converter. In this paper, discussion is given on digital implementation of carried-based randomized discontinuous PWM for active front end drives. A different scheme of ADC sampling synchronization with randomized DPWM is put forward to achieve improved power quality performance while keeping conducted emission spectrum smoothly spread.