Alternator control device

An alternator control device included in an on-board power supply system provided with an on-board battery, and an on-board alternator that performs a power generation operation to supply electric power to the battery, the alternator control device being configured to control the alternator and comprising:

• a battery state determination unit configured to determine whether or not a state of the battery is a predetermined normal state;
• a vehicle speed determination unit configured to determine whether or not a speed of a vehicle in which the on-board power supply system is installed is within a predetermined high speed range;
• a position determination unit configured to determine whether or not a position of the vehicle meets a predetermined positional condition;
• and
• an output voltage instruction unit configured to give an instruction to increase an output voltage of the alternator to a voltage that is greater than a reference voltage, if it is determined by the battery state determination unit that the state of the battery is not the predetermined normal state, if it is determined by the vehicle speed determination unit that the speed of the vehicle is within the predetermined high speed range, and if it is determined by the position determination unit that the position of the vehicle meets the positional condition,
• wherein the vehicle speed determination unit determines whether or not the speed of the vehicle is within the high speed range based on an output from a sensor installed in the vehicle, and
• the position determination unit determines that the positional condition is met in at least one of cases where the position of the vehicle is in a predetermined curve vicinity area on a predetermined arterial road and where the position of the vehicle is in a predetermined change-to-low-speed prospective area on a predetermined arterial road.