What is the principle of slip ring induction motor?
This motor runs on the principle of Faraday’s law of electromagnetic induction. When a stator winding is excited with an AC supply, the stator winding produces magnetic flux. Based on faraday’s law of electromagnetic induction, the rotor winding gets induced and generates a current of magnetic flux.
How do slip rings work?
HOW DOES A SLIP RING WORK? A slip ring passes electrical signals and power across a rotating interface using sliding electrical contacts. These contacts are typically a rotating ring and a stationary brush, or wiper, that slides along the ring surface during rotation.
What are slip ring motors used for?
A slip ring induction motor is capable of maintaining the highest torque at any slip. Even a high braking torque can be maintained easily. It is mainly used for high starting torque which makes use of an external resistance. They can help in speed control for lifts, railway traction, elevators, etc.
What is the application of slip ring induction machine?
The slip ring induction motors are also used for loads which require a gradual build-up of load. They are used for loads that requires speed control. Typical applications of wound rotor or slip ring induction motors are crushers, plunger pumps, cranes & hoists, elevators, compressors and conveyors.
What is slip formula?
If the revolving magnetic flux’s synchronous speed & the speed of rotor are Ns & Nr in the motor, then the speed among them can be equivalent to (Ns – Nr). So, slip can be determined as. S = (Ns – Nr) / Ns.
Which type of starter is used in a slip ring induction motor?
Rotor resistance starter is used for slip ring induction motors of high ratings.
What is the definition of a slip ring?
Definition of slip ring : one of two or more continuous conducting rings from which the brushes take or to which they deliver current in a generator or motor.
Which material is used to make slip rings?
A slip ring consists of 2 main components: rings and brushes. The ring provides the circuit path and is made up of an electrically conductive material such as brass, plated silver or coin silver, and is usually mounted on, but insulated from, a center shaft.
Where are slip rings used?
Slip rings are typically used within applications where there is unrestrained, intermittent or continuous rotation and power/data needs to be transmitted. Slip rings are also commonly used to neatly compact messy and interfering wires, which may be present when using other types of components which require rotation.
What are the advantages of slip ring induction motor?
The following are the advantages of slip ring induction motor: They have smooth acceleration under heavy loads. They have high overloading capacity. The speeds of induction motor with slip rings can be adjusted with the help of a resistance.
What is the unit of slip?
Definition of Slip The slip can also be represented in per unit(p.u). The fraction part of the synchronous speed is called the Fractional slip or per unit slip. The rotor speed of the motor can be given by following mathematical expression.
What happens when slip is zero?
What happens if the slip is zero? If Slip is equal to zero, rotor current is zero and torque is zero. The zero torque means motor will not rotate at all.
What are the applications of slip ring induction motor?
Some of the applications of slip ring induction motor are These motors are used where higher torque and low starting current are required. Used in applications like elevators, compressors, cranes, conveyors, hoists, and many more
What is the working principle of magnetic induction motor?
This motor runs on the principle of Faraday’s law of electromagnetic induction. When a stator winding is excited with an AC supply, the stator winding produces magnetic flux. Based on faraday’s law of electromagnetic induction, the rotor winding gets induced and generates a current of magnetic flux.
How does resistance affect phase difference in a slip ring motor?
We saw in the simple circuit that by increasing the resistance value we can decrease that phase difference. As a slip ring induction motor starts, the external resistance value is increased (Fig:11). This reduces the phase difference angle and the current induced approaches the ‘maximum torque condition’.
How to control speed of a ring type motor?
As the slip value increases the speed of the motor decreases with maintaining constant torque and this is possible only in ring-type. 2) Using Thyristor Circuit: The Speed control of this motor is controlled by using a thyristor ON/OFF circuit.