
242 Electrotechnical Systems
snubbers, the inner resistances of the electronic components, and the voltage drop in
them. The ballast resistors with big resistance are to be set at the outputs of the recti-
er and the CSI, noting that simulation is made noticeably quicker.
5.2.11 siMulation of iM soft-start
During direct IM start (by connected IM to the grid), the big current inrush (6–10
times of the rated current) in the IM windings and in the grid and considerable torque
oscillations appear that affect badly the mechanical part of an electric drive. The
soft-start systems are intended for reducing these phenomena. One of the often used
schemes ...