A study on the reduction of in-rush current for energy saving of single phase induction motor

In this paper, an analog controller is proposed to reduce in-rush current that happens during starting of a single phase induction motor within 200% of rated current depending on an international standard. The soft start method is used as the main conventional method that reduces inrush current and controls the input current through the main winding control. Capacitor starting of a single phase induction motor requires large starting torque. If the input electric power is less, the starting torque decreases and because starting time is delayed, electric power loss increases. Therefore, this paper discusses improved reduction of starting torque at main winding control which controls the auxiliary winding that is paralleled with the main winding that uses an electrical starting switch, and leads to energy saving during starting.