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Slip of induction motor plays an important role in the operation of the induction motor. The torque produced by the induction motor is directly proportional to induction motor slip. When the motor is loaded, greater torque is required to drive the load, therefore, slip increases and rotor speed decreases slightly.
What is slip power and its significance?
The slip power recovery (SPR) drive is an external system connected to the rotor circuit in place of the external resistors. The SPR provides speed and torque control like the resistors but can also recover the power taken off the rotor and feed it back into the power system to avoid energy waste.
What is the 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 slip in 3 phase motor?
This speed difference is called slip. Therefore, the difference between the synchronous speed Ns of the rotating stator field and the actual rotor speed N is called slip. The slip increase with load and is necessary for torque production. Slip speed is equal to the difference between rotor speed and synchronous speed.
What is slip electrical engineering?
In an electrical coupling, slip is defined simply as the difference between the speeds of the two rotating members. In an induction motor, slip is a measure of the difference between the machine’s synchronous speed and its shaft speed.
What do you mean by slip power?
SLIP-POWER: A PART OF THE AIR-GAP POWER WHICH IS NOT CONVERTED INTO MECHANICAL POWER IS CALLED SLIP POWER. IT IS REPRESENTED BY sPg. where s=slip, Pg= air-gap powerSLIP RECOVERY: THE AIR GAP POWER WHICH IS GETTING WASTED IN ROTOR IS FED BACK TO THE SUPPLY MAINS THIS IS CALLED SLIP RECOVERY.
What happens when slip is zero?
Zero slip means that rotor speed is equal to synchronous speed. If rotor is rotating at synchronous speed in the direction of rotating magnetic field the, there will be no flux cutting action, no emf in the rotor conductors, no current in rotor bar conductor and hence no development of electromagnetic torque.
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.
Why do you conduct slip test?
Explanation: Slip test is used to determine the q-axis reactance. Explanation: The impedance during slip test is low so the voltage drop will be less and the current will be more. Explanation: Slip test is conducted at low terminal voltage to avoid large slip in the synchronous machines.
What is full load slip?
The slip corresponding to full load speed of th motor is called full load slip. Example 1 : A 4 pole, 3 phase induction motor is supplied from Hz supply. Determine its synchronous speed. On full load, its speed is observed to be 1410 r.p.m. calculate its full load slip.
How is slip in motor calculated?
What is Slip in an Induction Motor? Definition: In Induction Motor, a slip is a speed among the rotary magnetic flux as well as rotor expressed in terms of for every unit synchronous speed. It can be measured in dimensionless & the value of this motor cannot be zero. S = (Ns – Nr) / Ns. Slip = (Ns-Nr/Ns)*100.
What is meant by slip frequency?
Slip frequency can be measured by determining the phase angle traversed in a defined period. For example, with a slip setting of 2 seconds (0.055 Hz) and slip frequency of 0.04 Hz, an angle of approx 29° (elec) is traversed before synchronising is permitted, as shown in Fig 12.15.
Can slip be negative?
If the rotor of an induction machine rotates above synchronous speed, slip is negative, as are torque, mechanical output power and air gap power. i.e. the machine is operating as a generator. Rotational losses are 2450W.
What causes motor slip?
Slip depends on motor parameters The traditional way to control wound-rotor-induction-motor speed is to increase slip by adding resistance in the rotor circuit. The slip of low-hp motors is higher than that of high-hp motors because rotor-winding resistance is greater in smaller motors.
What is synchronous speed and slip?
Slip is the difference between the synchronous speed of a motor and its actual speed. Mathematically it is determined by. Slip = Synchronous Speed − Actual Speed. Using the example above for synchronous speed of a motor with four poles operating at 60 hertz, the value was calculated to be 1800 RPM.
What do slip rings do?
“A slip ring is an electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure. A slip ring can be used in any electromechanical system that requires unrestrained, intermittent or continuous rotation while transmitting power and / or data.
What are the advantages of slip power recovery system?
The main advantage of this method is that a smooth speed control is possible. Similarly wide range of speed control is possible. Another advantage of the system is that the design of a rotary converter is practically independent of the speed control required.
What are the types of slip power recovery system?
Slip Energy Recovery is one of the methods of controlling the speed of an Induction motor. This method is also known as Static Scherbius Drive. In the rotor resistance control method, the slip power in the rotor circuit is wasted as I2R losses during the low-speed operation.
What is the formula for slip?
Slip speed is the speed difference between the Synchronous speed and Rotor speed. Slip speed = Synchronous speed – Rotor speed = Ns -N. Slip, s = (Ns – N) / Ns.
What is the value of slip at starting?
The difference between synchronous and actual speed of the rotor is called slip. At start, slip of the motor is unity. When the motor starts accelerating, the slip decreases and at the rated KW the slip of the motor is about 3–5 % of the synchronous speed of IM.
When slip is zero rotor will?
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 type of motor has a slip factor of 0 %?
In two-pole single-phase motors, the torque goes to zero at 100% slip (zero speed), so these require alterations to the stator such as shaded-poles to provide starting torque. A single phase induction motor requires separate starting circuitry to provide a rotating field to the motor.
