IMECE2008-67470 A THERMAL QUADRUPOLE-BASED MODEL FOR HEAT DIFFUSION IN A MULTILAYERED SYSTEM: APPLICATION TO DETERMINATION OF TRANSIENT PERFORMANCE OF A MEDIUM-VOLTAGE SOFT STARTER
ABSTRACT Adverse effects of starting-torque transients and high inrush currents in induction motors are typically mitigated by employing electronically controlled soft starting voltages through silicon controlled rectifiers (SCRs INTRODUCTION Starting a de-magnetised induction motor from standstill is a demanding and complex process. At the instant of switching on the power supply, all the energy necessary to magnetise the motor, to provide the acceleration force, and to supply the kinetic energy of the rotor and load, must be present together with the energy to overcome the mechanical and electrical losses in the motor. Doing this at full supply voltage places considerable stresses on the supply, the motor windings, and the iron cores of the stator and rotor