SOLUTION

The synchronous impedance method of finding voltage regulation of a synchronous motor is also known as the emf method.

Detailed Explanation

Normally for voltage regulation calculation, we use the following methods.

1. Synchronous impedance or emf method
2. Armature turn or mmf method
3. Zero PF or Potier method

Synchronous impedance method (EMF Method):

• The synchronous impedance method of calculating voltage regulation of an alternator is otherwise called the EMF method.
• The synchronous impedance method or the EMF method is based on the concept of replacing the effect of armature reaction with an imaginary reactance.
• This method is not accurate as it gives a result that is higher than the original value. That’s why it is called the pessimistic method.
• For calculating the regulation, the synchronous method requires the armature resistance per phase, the open-circuit characteristic, and the short circuit characteristic.