In this this course detailed procedure to determine voltage regulation of synchronous generator by

1) EMF or Synchronous Impedance Method

2) MMF or Ampere Turn Method

3) ZPF or Potier Method

is discussed.

The Synchronous Impedance Method or EMF Method is based on the concept of replacing the effect of armature reaction by an imaginary reactance.

MMF Method is also known as Ampere Turn Method.

The MMF method replaces the effect of armature leakage reactance with an equivalent additional armature reaction MMF so that this MMF may be combined with the armature reaction MMF.

In the synchronous Impedance, all the quantities are treated as EMF quantities as against this in MMF method all are treated as MMF quantities.

The Zero power factor (ZPF) method is used to determine the voltage regulation of synchronous generator or alternator. This method is also called Potier method. In the operation of an alternator, the armature resistance drop IRa and armature leakage reactance drop IXL are actually EMF quantities while the armature reaction is basically MMF quantity.

This test initially needs data of Open Circuit Test and Short Circuit Test.

Open circuit characteristics is obtained by conducting open circuit test in the Alternator.

Short circuit characteristics is obtained by conducting short circuit test in the Alternator.

The method described here all are indirect method of testing of an alternator / synchronous generator