What is slip What is synchronous speed What are motorgenerat

What is slip? What is synchronous speed? What are motor/generator poles and how do they affect speed? What is the relationship between rpm (rev/min) and rads/sec? What are typical applications of synchronous generators?

Solution

Slip: In short, the slip of an induction motor can be defined as the difference between its synchronous speed and its speed at full load. The speed performance of an electricmotor can be calculated by a method known as percent slip. The slip is essential for producing torque that increases with increasing load.

.Definition of 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.

Poles:it can magnetic type or electro magnetic type..in electro magnetic type the winding wound on it to behave like a magnet which is called pole.

Synchronous speed Ns = (120*f)/p

Where f=frequency of supply

P= no of poles

If poles increase in the machine then synchronous speed will decrease and vice-versa.

Rev/min= (2*pi)/60 rad/sec

Where pi=22/7

Applications:

Alternators or synchronous generators can be classified in may ways depending upon their application and design. According to application these machines are classified as-

Automotive type - used in modern automobile.
Diesel electric locomotive type - used in diesel electric multiple unit.
Marine type - used in marine.
Brush less type - used in electrical power generation plant as main source of power.
Radio alternators - used for low brand radio frequency transmission.