Analysis of voltage dips in PWM AC-DC converters

This paper presents results from about comparative analysis of the effect of voltage dip on AC-DC converters. Voltage dip analysis is a complex stochastic issue, since it involves a large variety of random factors, such as: type of short-circuits in the power system, location of faults, protective system performance and atmospheric discharges. Among all categories of electrical disturbances, the voltage dip (sag) and momentary interruption are the nemeses of the automated industrial process. In particular, the paper analyzes the effect of dip types A, C and D on the minimum dc-bus voltage of PWM boost rectifier compared with traditional diodes rectifier. The principal conclusion from the analysis is that the AC-DC converters can be unaffected by the most generalized voltage dips with small dc-bus capacitance if a relatively low-cost boost follower pre-regulator is added at the front end of the diode bridge