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Definition: The slip in an induction motor is the difference between the main flux speed and their rotor speed. The symbol S represents the slip. It is expressed by the percentage of synchronous speed.
What is slip in an induction motor?
“Slip” in an AC induction motor is defined as: As the speed of the rotor drops below the stator speed, or synchronous speed, the rotation rate of the magnetic field in the rotor increases, inducing more current in the rotor’s windings and creating more torque. Slip is required to produce torque.
Why is slip important in an induction motor?
In induction motor, slip is important because slip determines torque and also the machine behaviour. Explained as follows: (1) Torque depends on rotor power factor which, in turn, depends on slip. So, torque is lowest when slip(s) is equal to 1 i.e. at standstill.
Why there is no slip in synchronous motor?
Because the rotor turns at the same speed as synchronous speed (speed of the rotating magnetic field), there is no slip. The speed of rotation of the motor is constant in a synchronous motor, and does not vary with load, as in an induction motor.
What is the slip?
A slip is a woman’s undergarment worn beneath a dress or skirt. A full slip hangs from the shoulders, usually by means of narrow straps, and extends from the breast to the fashionable skirt length. A half slip (or waist slip) hangs from the waist.
How does an induction motor start?
A three-phase Induction Motor is Self Starting. When the supply is connected to the stator of a three-phase induction motor, a rotating magnetic field is produced, and the rotor begins rotating and the induction motor starts.
What causes motor slip?
The interaction of currents flowing in the rotor bars and the stators’ rotating magnetic field generate torque. In actual operation, rotor speed always lags the magnetic field’s speed, allowing the rotor bars to cut magnetic lines of force and produce useful torque. This speed difference is called slip speed.
What is slip speed?
The speed at which the induction motor work is known as the slip speed. The difference between the synchronous speed and the actual speed of the rotor is known as the slip speed. In other words, the slip speed shows the relative speed of the rotor concerning the speed of the field.
What is slip and its importance?
Importance of Slip in Induction Motor. In the induction motor rotor always rotates speed less than synchronous speed. The difference between the rotor speed (N) and the rotating magnetic flux speed (Ns) is called slip.
Can slip be more than 1?
Slip more than 1 implies that, rotor is rotating in a direction opposite to the direction of rotation of magnetic flux. This means if magnetic flux is rotating in clockwise direction, then rotor is rotating in anticlockwise direction or vice versa. Therefore, the relative speed between them will be (Ns + Nr).
Why it is called slip test?
The method used to determine Xq and Xd, the direct and quadrature axis reactance is called slip test. Current induced in the damper winding of alternator will produce an appreciable error. Induced voltage in the open circuit field may reach dangerous values.
What is synchronous speed?
: a definite speed for an alternating-current machine that is dependent on the frequency of the supply circuit because the rotating member passes one pair of poles for each alternation of the alternating current.
What is slip formula?
Formula to find slip = (ns – n) x 100/ns. substitute the values in the above formulas. speed difference = 1500 – 1450. = 50. slip = 50/1500 x 100.
What is Torque slip?
The torque slip curve for an induction motor gives us the information about the variation of torque with the slip. The slip is defined as the ratio of difference of synchronous speed and actual rotor speed to the synchronous speed of the machine.
What is normal slip of an induction motor?
Because of this speed difference, the motor rotates at a speed slightly slower than the synchronous speed. Slip is normally expressed in percentage. Slip of a power induction motor is 2 to 3% when the motor is operated under the rated load.
What will happen when the slip is 100 and zero?
What will happen when the slip is 100 and zero? As the rotor ends are short circuited current flows through the rotor. So when slip is zero there is no phase difference between stator flux and rotor flux and there is no torque exerted on rotor and rotor does not rotate .
What is the motor slip?
Slip is the differentiation between synchronous and asynchronous speed. The difference between the synchronous speed of the electric motor magnetic field, and the shaft rotating speed is slip – measured in RPM or frequency. Slip increases with increasing load – providing a greater torque.
What is range of slip of induction motor for no load?
No-load slip value percentage in an induction motor is: More than 50% About 30% Around 5% Less than 1%Mar 9, 2020
What are the types of motors?
Types of Electric Motors
- AC Brushless Motors. AC brushless motors are some of the most popular in motion control.
- DC Brushed Motors. In a DC brushed motor, brush orientation on the stator determines current flow.
- DC Brushless Motors.
- Direct Drive.
- Linear Motors.
- Servo Motors.
- Stepper Motors.
What happens when slip of induction motor is zero?
In motors the number of rotor slots and stator slots are different and thus cogging (magnetic locking) can’t happen. And thus The slip motor can’t run at rated speed. At synchronous speed,slip is zero and hence torque developed by the motor is zero.
Can slip be negative?
From the above equation it is clear that, for slip to be negative, the rotor speed should be greater than synchronous speed. Hence,Negative slip is a situation when an induction motor becomes an Hence,Negative slip is a situation when an induction motor becomes an induction generator.
What are the types of induction motor?
Types of Induction Motor: A Concise and Useful Guild
- Types of Single-Phase Induction Motors. Split Phase Induction Motors. 2&3. Capacitor Start and Capacitor Start Capacitor Run Induction Motors. Shaded Pole Induction Motors.
- Types of Three-Phase Induction Motors. Squirrel Cage Induction Motor. Slip-ring or Wound Rotor Induction Motor.
