Application of random PWM techniques for reducing the electromagnetic interference of Vienna rectifiers in distribution power system

Random pulse width modulation (RPWM) technique has been employed to generate the control signals of Vienna-type rectifier. This technique is compared to two conventional techniques (Hysteresis-band and ramp comparison with fix frequency carrier signal). Simulation results are illustrated for three approaches. The results verify significantly reduction of high frequency harmonics magnitude; and consequently overcome electromagnetic interference (EMI) problem in this active type of rectifier.