Regulation of definite pole alternators

Since the method recommended by the A. I. E. E. for obtaining regulation of alternators from no-load saturation, short-circuit curve and armature resistance in most cases gives incorrect results, another method called the “triangle method” is suggested. This method requires the same tests as the A. I. E. E. method, and. drives the regulation by means of the Kapp diagram from an estimated full load zero power factor saturation curve, which in turn is determined with the aid of Potier's triangle. Potier's triangle is derived from no-load saturation and short-circuit curve by means of a simplified equation for armature reaction. A series of tables follows, in which regulations obtained by triangle and A. I. E. E. methods are compared with results obtained from actual test. The tables prove that the triangle method is the more accurate. Hence the suggestion to supersede the present A. I. E. E. method by the triangle method.