This is the most common solution for the speed control of induction motor. Like the above method, if the system frequency is decreased keeping the rated source voltage, the flux of air gap will be saturated.
What are methods of speed control of induction motor?
Speed Control Methods of Induction Motor:
- Control From Stator Side:
- Control From Rotor Side:
- Speed Control by frequency variation:
- Speed Control By Pole Changing:
- Speed control by varying Supply voltage:
- Speed control by varying Rotor Resistance:
- Speed control by injected EMF:
- Speed control by Cascade Connection:
Which method of speed control of induction motor is complicated?
For the Induction Motor (IM) the technique is used as Volts/Hertz constant. Vector control is more complex technique than scalar control, the evolution of which was inexorable, since scalar control technique cannot be applied for controlling systems with dynamic behavior.
Which of the following methods of speed control is not affected through stator side?
Which of the following methods of speed control is not affected through stator side? Change of rotor resistance.
Where the stator voltage control is suitable for the speed control of induction motor Mcq?
This stator voltage control method is suitable for the applications where the load torque decreases with the speed. For example- In the fan load. This method gives a speed control only below the normal rated speed as the operation of the voltages if higher than the rated voltage is not admissible.
What are the methods of speed control of DC motors?
Thus, there are three general methods of speed control of D.C. Motors.
- Resistance variation in the armature circuit: This method is called armature resistance control or Rheostat control.
- Variation of field flux Ф This method is called field flux control.
- Variation of the applied voltage.
What are the starting methods of induction motor?
Starting methods of Induction motor include:
- Direct –On– line (DOL) starters for less than 10 Kw motors.
- Star–Delta starters for large motors. The stator winding is initially connected in a star configuration and later on changed over to a Delta connection, when the motor reaches rated speed.
- Auto transformer.
How can we increase the RPM of induction motor?
To speed up an induction motor, you could 1) reduce the load on it (may increase speed 2 or 3%. 2) increase the frequency of the supply power 3) re-wind the stator to have fewer pole pairs. Does voltage affect AC motor speed? Voltage affects the torque and the frequency decides the motor speed (for a given no.
How do you control motor speed?
Thus, the speed of a DC motor can be controlled in three ways: By varying the supply voltage. By varying the flux, and by varying the current through the field winding. By varying the armature voltage, and by varying the armature resistance.
Why is speed control of induction motor necessary?
Speed of a DC shunt motor can be varied very easily with good efficiency, but in case of Induction motors, speed reduction is accompanied by a corresponding loss of efficiency and poor power factor. As induction motors are widely being used, their speed control may be required in many applications.
Which DC motor is preferred for constant speed?
Explanation: Rotary compressor generally demand constant speed operation throughout the load. Sometimes, DC machines are not able to produce constant speed throughout the process hence, synchronous machine is used. 4.
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 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.
Which method of speed control of induction motor from stator side is not possible?
Multiple Stator Winding Method
Using a switching arrangement, at a time, supply is given to one winding only and hence speed control is possible. Disadvantages of this method are that the smooth speed control is not possible. This method is more costly and less efficient as two different stator windings are required.
Which is the most effective way of controlling a DC shunt motor above rated speed?
Shunt motor is a special type of DC motor which runs at a constant speed. But using field and armature rheostat control method we can make it more versatile. Field rheostat provides above normal speed and armature rheostat provides wide range of below normal speed.
Which motor is suitable for lift?
AC slip ring or DC compound motors are prefer for lifts. Shunt type commutator motors are preferred in case of single phase installation. The latest lift designs use 3-phase induction motors with variable frequency drive electronic controls.