Power generation control unit determining maximum excitation current of power generator mounted on vehicle

A control unit that controls a power generator mounted on a vehicle, the power generator including a field winding through which an excitation current flows, the excitation current being controlled by the control unit so as to control a power generated by the power generator, the control unit comprising:

• current detecting means for detecting the excitation current that flows through the field winding;
• communication means for communicating with external equipment so as to receive a first upper limit;
• holding means for holding a second upper limit inside the power generator;
• maximum current determining means for determining a maximum current value to be the second upper limit when the first upper limit has not been received by the communication means or when the first upper limit received by the communication means is more than or equal to the second upper limit, and determining the maximum current value to be the first upper limit when the first upper limit received by the communication means is less than the second upper limit;
• and
• current control means for controlling the excitation current detected by the current detecting means to be within the maximum current value.