The Feature of Regulating and V-characteristics of Synchronous Electrical Machines

  • P. Kostrauskas Kaunas University of Technology
  • A. Kalvaitis Kaunas University of Technology
  • L. Andriušienė Kaunas University of Technology


There is known that regulating characteristic of synchronous electrical machine specifies the dependence of excitation current on the load current, when duty is off - line and voltage at armature terminals, load factor and frequency are constant. Nowadays regulating characteristic is obtained by experimental way. The paper presents analysis expressions of regulating characteristics – that is hyperbolas witch locus of vertices is described by ellipsis. Under the no-load conditions of synchronous machine the active resistance of armature winding is equal zero, and regulating characteristic is described by equations of two concurrent lines. The ordinate of these straights junction is equal zero value of excitation current. The paper presents that when electromagnetic power and power factor are equal zero and active resistance of armature winding is equal zero, V-characteristic (parallel duty) coincides with regulating characteristic (off–line duty). The main theoretical presumptions have been tested experimentally and offered a suggestion of practical application. Ill. 2, bibl. 5 (in Lithuanian, summaries in Lithuanian, English and Russian).