SOLUTION

Voltage regulation of an alternator can be obtained using the zero power factor method.

Detailed Explanation

ZPF or Potier triangle method:

• This method depends on the separation of the leakage reactance of armature and its effects.
• It is used to obtain the leakage reactance and field current equivalent of armature reaction.
• It is also called a general method of voltage regulation.
• It is the most accurate method of voltage regulation.
• For calculating the regulation, it requires open circuit characteristics and zero power factor characteristics.

​The following assumptions are made in this method.

• The armature resistance is neglected.
• The O.C.C taken on no-load accurately represents the relation between MMF and voltage on load.
• The leakage reactance voltage is independent of excitation.
• The armature reaction MMF is constant.