• Synchronous motor: Stator poles rotate at the synchronous speed (Ns) when fed with a three phase supply. The rotor is fed with a DC supply. The rotor needs to be rotated at a speed near to the synchronous speed during starting. If done so, the rotor poles get magnetically coupled with the rotating stator poles, and thus the rotor starts rotating at the synchronous speed.

• Synchronous motor always runs at a speed equal to its synchronous speed. Actual speed = Synchronous speed or N = Ns = 120f/P • Learn more about. • Induction motor: When the stator is fed with two or three phase AC supply, a is produced. The relative speed between stator's rotating magnetic field and the rotor will cause an induced current in the rotor conductors. The rotor current gives rise to the rotor flux. According to, the direction of this induced current is such that it will tend to oppose the cause of its production, i.e. Relative speed between stator's RMF and the rotor. Asetek chill control software.

Synchronous motor; Induction motor: Stator winding is similar to that of a synchronous motor. It is wound for a specific number of poles. A squirrel cage rotor or a wound rotor can be used. In squirrel cage rotor, the rotor bars are permanently short-circuited with end rings.

Thus, the rotor will try to catch up with the RMF and reduce the relative speed. • Induction motor always runs at a speed which is less than the synchronous speed. • Synchronous motors require an additional DC power source for energizing rotor winding. Induction motors do not require any additional power source. • Slip rings and brushes are required in synchronous motors, but not in Induction motors (except wound type induction motor in which slip ring motors are used to add external resistance to the rotor winding). • Synchronous motors require additional starting mechanism to initially rotate the rotor near to the synchronous speed. No starting mechanism is required in induction motors. Tomb raider iii walkthrough.

• The power factor of a synchronous motor can be adjusted to lagging, unity or leading by varying the excitation, whereas, an induction motor always runs at lagging power factor. • Synchronous motors are generally more efficient than induction motors. • Synchronous motors are costlier.

Introduction We have seen the and discussed in detail the working principle, concept behind rotor rotation and many other aspects of induction motor. Now let us discuss in detail, the most common form of induction motor, the “Squirrel cage” induction motor. The reason for the name “Squirrel cage” is because of the type of rotor used in these motors. Almost 95% of the induction motors used is of squirrel cage type. And in the previous article on Types of Electrical Motors, we have classified Induction Motors based on the type of rotor used. Induction Motors & 2. Slip-Ring or Wound- Construction Of Squirrel Cage Induction Motor Any Induction Motor has a Stator and a Rotor.

The construction of Stator for any induction motor is almost the same. But the rotor construction differs with respect to the type which is specified above. The stator is the outer most component in the motor which can be seen. It may be constructed for single phase, three phase or even poly phase motors. But basically only the windings on the stator vary, not the basic layout of the stator. It is almost same for any given synchronous motor or a generator. It is made up of number of stampings, which are slotted to receive the windings.

Lets see the construction of a three phase stator. The three phase windings are placed on the slots of laminated core and these windings are electrically spaced 120 degrees apart. These windings are connected as either star or delta depending upon the requirement. The leads are taken out usually three in number, brought out to the terminal box mounted on the motor frame. The insulation between the windings are generally varnish or oxide coated. The Rotor: Squirrel Cage Rotor.