Power supply control apparatus, vehicle and method of controlling power supply

A power supply control apparatus of a vehicle, the vehicle comprising an engine;

• a DC-DC converter connected between high-voltage wiring and low-voltage wiring;
• a generator connected with the high-voltage wiring and configured to generate electric power by utilizing rotation of the engine;
• a high-voltage secondary battery connected with the high-voltage wiring via a relay;
• high-voltage auxiliary machinery connected with the high-voltage wiring;
• a low-voltage secondary battery connected with the low-voltage wiring;
• and low-voltage auxiliary machinery connected with the low-voltage wiring, wherein
• (i) in a first case where a total power consumption of the high-voltage auxiliary machinery and the low-voltage auxiliary machinery is greater than a first reference value in a state that the high-voltage secondary battery is disconnected from the high-voltage wiring by the relay, the power supply control apparatus then sets a lower value to a target control value of output voltage of the generator, compared with a case where the total power consumption is less than or equal to the first reference value;
• and
• (ii) in a second case where the total power consumption of the high-voltage auxiliary machinery and the low-voltage auxiliary machinery is less than a second reference value that is less than or equal to the first reference value in the state that the high-voltage secondary battery is disconnected from the high-voltage wiring by the relay, the power supply control apparatus then sets a higher value to the target control value of output voltage of the generator, compared with a case where the total power consumption is more than or equal to the second reference value.