Question

Which of the following is not a demerit of AC servomotors?
1. lower efficiency
2. Used in low power applications
3. Speed control and difficult to install
4. non-linear characteristics

Answer 1

Correct Answer - Option 1 : lower efficiency

Advantage and Dis-advantage of AC Servomotor:

Advantages:

• High output power relative to motor size and power
• The encoder determines accuracy and resolution.
• Resonance and vibration-free operation
• High efficiency
• There is no out-of-step condition, as a heavy load is placed on the motor the driver will increase the current to the motor
• High-speed operation is possible

Disadvantages:

• Require tuning to stabilize the feedback loop
• Available for low power rating only
• Complex, require encoder
• Poor motor controlling 
• The motor can be damaged by sustained overload.
• Non-linear characteristics of operation