Modelling of soft starters for automated electric drive

In this paper we investigated the conditions of favorable start-up of fixed-speed induction motors in order to increase the functional reliability of the engines. The methods of controlled soft start of induction electric motors with a squirrel-cage rotors are investigated. The study of the mathematical model of induction motors for determining the dependencies of reducing the dynamic component of the transient electromagnetic moment and the magnitude of the starting current. A computer simulation to identify the effectiveness of different methods of controlled start-up of induction motor was carried out. To generate the starters' models, the MatLab modelling application, Simulink and SimPowerSystems block libraries were used. Based on the results of transient processes simulation in MatLab, the comparative characteristics for different methods of starting an induction motor were given. (paper)