Slip Ring Induction Motor Rotor Current

Slip rings i m provides some advantages like provides high starting torque low starting current and it improves the power factor.

Slip ring induction motor rotor current.

The slip ring induction motor has two distinctly separate parts one is the stator and other is the rotor. Adjusting the resistance allows control of the speed torque characteristic of the motor. It consists laminated cylindrical core which has a semi closed slot at the outer periphery and carries three phase insulated winding. As a slip ring induction motor starts the external resistance value is increased fig 11.

A wound rotor induction motor has a stator like a squirrel cage induction motor but a rotor with insulated windings brought out via slip rings and brushes. This way slip ring induction motors will be able to produce high torque even as they are starting. The function of a three phase slip ring induction motor is shown in the figure below. A wound rotor motor uses three slip rings typically made of copper or a copper alloy mounted to but insulated from the motor shaft.

Wound type rotor or slip ring type rotor this type of rotor is also made up of laminated cold rolled grain oriented silicon steel to reduce eddy current loss and hysteresis loss. The stator circuit is rated as same in the squirrel cage motor but the rotor is rated in frame voltage or short circuit current. Their sole purpose is to allow resistance to be placed in series with the rotor windings while starting figure below. As rotor current is directly proportional to the speed and torque of three phase ring type.

The motor which employing the wound rotor is known as a slip ring induction motor or phase wound motor. It is controlled by varying the rotor current of the motor. The rotor winding is distributed as well short pitched to get a sinusoidal emf output. A wound rotor motor also known as slip ring rotor motor is a type of induction motor where the rotor windings are connected through slip rings to external resistance.

However no power is applied to the slip rings. Slip ring induction motor is one of the types of 3 phase induction motor and is a wound rotor motor type. To achieve this the rotor ac current is converted by means of a three phase. Because of various advantages like low initial current high starting torque and improved power factor it is used in applications that require high torque cranes and elevators.

Definition of slip ring motor.