Method for controlling charging voltage of 12V auxiliary battery for hybrid vehicle

摘要

The present invention provides a method for controlling a charging voltage of a 12V auxiliary battery for a hybrid vehicle, which can (1) improve charging efficiency of an auxiliary battery by increasing the output voltage of a DC-DC converter during cold start when the outside air temperature is low, (2) improve the charging efficiency of the auxiliary battery by increasing or decreasing the output power of the DC-DC converter according to the state of charge of the auxiliary battery and by increasing the output voltage of the DC-DC converter when many electrical loads are turned on, and (3) allow the DC-DC converter to provide continuous power supply for charging the auxiliary battery by turning on a main switch disposed between a high voltage battery and the DC-DC converter based on a reverse power conversion operation of the DC-DC converter even in the case where the voltage of the auxiliary battery falls below 9V.

主权项

1. A method for controlling a charging voltage of a 12V auxiliary battery for a hybrid vehicle, the method comprising:
comparing an outside air temperature with a boundary temperature once the hybrid vehicle is started; when the outside air temperature is lower than the boundary temperature, measuring the voltage of a 12V auxiliary battery; and when the voltage of the 12V auxiliary battery is beyond a predetermined reference voltage range and the outside temperature is lower than the boundary temperature, increasing an output voltage from a DC-DC converter to the 12V auxiliary battery.