Ac motor for direct drive applications

ac motor for direct drive applications

Could be saved by efficient energy improvement technologies such as VFDs.
Variable Frequency Since motor speed depends on the speed of the rotating field, speed control can be effected by changing the frequency super retro squad game of the AC power supplied to tiny tower vegas cheats the motor.
Only about 3 of the total installed base of AC motors are provided with AC drives. .
Single Phase Induction Motors At first sight it might be assumed that it would be impossible to create a rotating field using only a single phase supply.Applications Used where regulated speed control is required in applications suc as metering pumps and industrial process equipment.As the motor approaches synchronous speed it will suddenly snap in to synchronisation.The induction motor can be considered as an AC transformer with a rotating secondary winding.However, it is estimated that drive technology is adopted in as many as 30-40 of all newly installed motors.Usually an induction motor draws 5 to 7 times its rated current during starting before the speed builds up and the current is modified by the back EMF.See Alternative Motor Action.It can therefore lock on to the rotating field.History, transformer Action, the stator carries the motor primary windings and is connected to the power source.Characteristics One of the major advantages of the induction motor is that it does not need a commutator.In wound rotor motors the starting current can be limited by increasing the resistance in series with the rotor windings.
They are now finding use in automotive applications for electric and hybrid electric vehicles.
A short circuited turn of thick copper, known as the shading ring, is mounted in a slot in the pole piece.
B in the air gap (and the relative motion, called the slip, of the rotor with respect to the rotating field as we shall see below).Characteristics The synchronous reluctance motor is not self starting without the squirrel cage.They are normally constant speed devices whose speed is proportional to the mains frequency.In other words, the rotating flux field appears to the stator as the north and south poles of a magnet rotating about the stator.They are difficult to start on mains frequency because the rotating field is too fast so they need to start at lower frequency or they need unexcited auxiliary windings or a rudimentary squirrel cage to bring the rotor up to synchronous speed.