Patent ID: 8723486

Claim:
A device for controlling power generation of a power generator mounted on a vehicle, the device comprising: switching means connected to a field winding of the power generator, for switching current flowing through the field winding to be ON and OFF; voltage control means for controlling the switching means to supply an excitation current to the power generator, wherein the voltage control means controls the switching means to gradually increase the excitation current when the excitation current is increasing whereby the voltage control means maintains an output voltage of the power generator to be a predetermined value; detecting means for detecting a startup state indicating an engine startup and for detecting normal state when the startup state is terminated; startup control means for controlling the voltage control means when the startup state is detected by the detecting means, the startup control means controlling voltage control means to start power generation when a frequency of a phase voltage appears at a stator winding of the power generator exceeds a first reference frequency, and controlling the voltage control means to stop power generation when the frequency of the phase voltage is lower than the first reference frequency; and normal state control means for controlling the voltage control means when the normal state is detected by the detecting means, the normal state control means controlling the voltage control means to continue power generation while the frequency of the phase voltage exceeds the first reference frequency, and to stop power generation when the frequency of the phase voltage is lower than a second reference frequency that is lower than the first reference frequency.