How many methods are present in the self starting of the single phase induction motor?

For self-starting a single-phase induction motor, there are primarily three methods used:

1. Split-phase induction motor method: In this method, the stator is equipped with two windings – a main winding and an auxiliary winding. The auxiliary winding, which has a higher resistance than the main winding, creates a phase difference in the magnetic field to start the motor. Once the motor reaches a certain speed, a centrifugal switch or electronic controller disconnects the auxiliary winding.

2. Capacitor start motor method: Similar to the split-phase motor, this method uses a capacitor in series with the auxiliary winding to create a greater phase difference between the currents in the main and auxiliary windings. This increases starting torque compared to a split-phase motor. The auxiliary winding and capacitor are disconnected from the circuit once the motor reaches around 75-80% of its rated speed, typically using a centrifugal switch.

3. Capacitor start-capacitor run motor method: This method employs two capacitors: a start capacitor and a run capacitor. The start capacitor is used only during the start-up phase to increase starting torque, while the run capacitor remains connected to the auxiliary winding during operation, improving the motor’s efficiency and torque characteristics. This approach provides better performance than the capacitor start motor and the split-phase motor methods.

These are the basic methods commonly used to make single-phase induction motors self-starting. Each method has its unique advantages and is chosen based on the specific requirements of