When adjusting excitation current, the change is E, generator stator current and power factor has been changing。

Keep minimum 1, the stator current, the cosine phi = 1, this kind of circumstance is called normal excitation generator, generator active power only.

2, on the basis of normal excitation increase generator excitation current, the E2 > E1, referred to as the excitation, the voltage of the stator current I behind U, generator besides give active power to the grid, also issued a perceptual reactive power to the grid.

Reduce 3, on the basis of normal excitation generator excitation current, the E3 < E1, called owe excitation, the voltage of the stator current (I) ahead of U, generator besides give active power to the grid, also send a capacitive reactive power to the grid, and absorb the inductive reactive power from power grid.

4, when the generator's operation with late, active power and the inductive reactive power supply system, to the active power and reactive power table all positive;Into the runtime, active power and the capacitive reactive power supply system, the active power table indicates positive, indicates a negative reactive power meter.