Synchronous generator: Capability curves
The capabilty curves of a synchronous generator operating at rated voltage V give the maximum active- and reactive-power loadings that can be suplied without exceeding the KVA rating (armature heating limit) or the field heating limit. Dragging point R which establishes the rated operating conditions changes the power factor. The slider KVA controls the rating. Dragging point A shows the effects of machine reactance, explicitly y(A) = -V/X. The stabilty limit is reached when δ = 90°.
© M. Riaz