Parallel Operation of Compound Generator

Parallel Operation of Compound Generator Points : Parallel Operation of Compound Generator Since these machines possess winding in series with the armature and usually having a rising characteristics, it is again necessary to equalize their field currents. This is usually affected by means of an auxiliary bar on the main switch board, the bar. being called the “equalizer bus bar”. Essential connections for parallel operation of compound generators. In absence of the equalizing bar, an accidental increase in the generated voltage of one machine causes it to supply more load current which in time strengthens its series field. This increases the generated emf further, with still further increase in its load current. When the equalizing conductor is used, two series field coil windings are connected in parallel and this cumulative action can not take place. An, increase in generated emf of one machine increases its armature current but series field is not strengthened so that successful parallel operation is possible. The equalizer should be connected at the junction of interpole and series field windings. This is necessary so that the interpole winding carries the armature current. For satisfactory operation, the resistance of the equalizing connector should be very small in comparison with that of the field coils.