An Induction Machines is a device using electrical energy to produce mechanical energy Electric energy —-> mechanical energy
There are several type of Motors available on industry and today we are going to discuss on AC Machines and follwoing are types of ac machines.
There are so many advantages and disadvantages of Alternative Current Induction Machines over other types of motors.
Before we go deep in to advantages and disadvantages of AC Induction motors we will check about what are the types of motors available in electrical industry.
AC Motors divide in to Synchronous Motors and Induction motor and then Induction motors divide in to Single phase and Three Phase motor.
Advantages of Induction Machines
A series of three windings in the stator section with a simple rotating section rotor. The changing field caused by the 50 or 60 Hz This type of Ac motor winding are easy to maintain and design. So these kind of AC motor got very simple form of design unlike complex designs in DC and special type of motors.
The AC motor has the advantage of being the lowest cost motor for applications requiring more than about 1/2 hp (325 watts) of power. This is due to the simple design of the motor. And by compare to other type of motors such as DC motor’s this type of motors are very cheap.
This indicates how AC (Auxiliary Current )motors are Reliable than other type of motors such as DC ( Direct Current ) motors.
AC motors are extremely reliable compared with other type of motors and the operation is also very easy.
Other Advantages of AC motors
• Low maintenance operation.
• There are no brushes to replace.
• AC motor can expect to need new bearings after several years of operation.
• If the application is well designed
Disadvantages of Induction Machines
Expensive speed control
Speed control is expensive and the electronics required to handle an AC inverter are considerably more expensive AC inverters and AC motors are usually more cost-effective than DC motors and DC drives for applications larger than about 10 horsepower, because of cost savings in the AC motor.
Poor positioning control
Positioning control is expensive and crude. Even a vector drive is very crude when controlling a standard AC motor.
High starting current
Squirrel cage motors suffer from drawing high starting current (some 6-8 times full load current) so I2R losses at starting are much greater than the full load. Lengthy starting periods thus cause early failure. Direct on line (DOL) starting is usually the more favored. I have mentions some motor starting methods in motor controlling section of this report.
By Comparing Advantages and disadvantage of AC motors its provide significant advantages over other type of motors so in most of the industries in Engineering filed AC motors are widely used due to benefits of it.