The regulation of an
alternator can be determined by various methods. In case of small
capacity alternators it can be determined by direct loading test while
for large capacity alternators it can be determined by synchronous
impedance method.
The synchronous impedance method has some short comings. Another method
which is popularly used is ampere-turns method. But this method also
has certain disadvantages. The disadvantages of these two methods are
overcome in a method called zero power factor method. Another important
theory which gives accurate results is called Blondel's two reaction
theory. Thus there are following methods available to determine the
voltage regulation of an alternator,
1. Direct loading method
2. Synchronous impedance method or E.M.F. method
3. Ampere-turns method or M.M.F. method
4. Zero power factor method or potier triangle method
5. ASA modified from of M.M.F. method
6. Two reaction theory
