Plugging of induction motor

Plugging is one of the methods used for braking an induction motor. It creates a counter torque to rapidly bring the motor to a stop

What Is Plugging?

Plugging involves reversing two supply phases, which reverses the direction of the stator magnetic field. The rotor, still rotating in the original direction, sees a rapidly increasing slip, resulting in a strong braking torque.

Plugging Torque-Speed Curve

• The torque becomes negative, decelerating the rotor
• Plugging torque is usually 75–100% of full-load torque
• Speed decays rapidly to zero