DCDC output voltage control method and control system for hybrid electric vehicle

A DCDC output voltage control method for a hybrid electric vehicle, the vehicle comprising a DCDC converter for converting a voltage of a high-voltage battery into a low voltage used for a low-voltage load of the vehicle in a buck operation mode and outputting the low voltage, the method comprising:

• when the DCDC converter is in the buck operation mode, determining whether the vehicle is in a high power output demand state or an abnormal engine flame-out state;
• if so, setting an output voltage of the DCDC converter to a normal target voltage, so as to control the DCDC converter to output according to the normal target voltage;
• otherwise, determining whether the low-voltage load has a charging voltage boost demand, and when the low-voltage load has the charging voltage boost demand and an electric quantity of the high-voltage battery is greater than an electric quantity threshold, setting the output voltage of the DCDC converter according to a voltage level corresponding to the charging voltage boost demand, so as to meet a charging demand of the low-voltage load.