The dc motor current is very high at starting when the back emf of the motor is zero. This high initial current can damage the motor if the inrush current is not limited to a safe value. Starters are used to limit the high inrush current. Or a device with a variable resistor which is usually connected in series with the armature windings of the motor so that the starting inrush current can be reduced to a safe value. However, limiting the high inrush current is a problem. This paper discusses control methods for limiting this high starting current to a save value; and a step by step design of an automatic three point simulated in Matlab/Simulink environment.

Keywords : Armature Winding, Back EMF, High Inrush Current, Variable Resistor.