The influence of the DC link inductor design on the rectifier voltage stress in an adjustable speed drive during a mains voltage surge

The use of diode bridge rectifiers in modern adjustable speed drives (ASD) is widespread due to their simplicity and low cost. The diode bridge rectifier is commonly used in conjunction with a passive L-C filter to provide a suitable DC link. The design of the L-C filter involves many factors including its impact on the ASD performance during a mains voltage surge. This paper presents an analytical method to determine the impact of the DC link inductor design on the diode bridge rectifier voltage stress during a mains voltage surge. Several common DC link inductor designs are considered and their effect on the diode bridge rectifier peak voltage stress is shown to be a function of the mutual inductance and also the loading condition of the ASD. Experimental results are obtained that confirm both the analytical and computer simulation models.