High frequency harmonics emission of modern power electronic AC-DC converters

Abstract

Modern AC/DC converters with bidirectional power flow employing PWM boost topology generate harmonic distortions of input current in relatively high frequency range tightly related to modulation carrier frequency. These frequencies and its multiples in typical applications are usually located in frequency range from single up to several of kHz. Increased harmonic emission in this frequency range can easily and harmfully influence sensitive control and measurement systems what occurs more often nowadays in applications where high power AC/DC PWM boost converted are used. This paper presents a comparison of current harmonic emission of PWM boost rectifiers with relation to classic diode rectifiers. New class of electromagnetic compatibility problems arising in power system are underlined as a result of increased harmonic distortions emission in frequency range up to 9 kHz.