Why does the output voltage of an alternator increases when it is connected to Capacitive load?
The equivalent circuit of an alternator consists of the an ideal AC voltage generator in series with a "source impedance" which can be modelled by a resistor in series with an inductor. When this impedance is shunted with a capacitor, then, for a certain range of values of the R, L, and C components, a "resonant rise" in the voltage across the inductor will occur, with the result that the overall output voltage is increased.