Method for controlling a precharge circuit of a DC link in a motor vehicle and high-voltage battery with the precharge circuit and motor vehicle

摘要

The invention relates to a method for controlling a precharge circuit (V) by means of which in a motor vehicle (10) an electrical supply unit (11) is coupled to an intermediate circuit (16) having a DC link capacitance (C), wherein a control unit (23) Connecting the supply unit (11) to the intermediate circuit (16) first an electrical current (25) of the supply unit (11) via a pre-charge resistor (32) of the precharge circuit (V) out and then the Vorladewiderstand (32) is bridged and wherein before a subsequent , renewed connection of the supply unit (11), an overheating criterion for the precharge resistor (32) is checked, and if the overheating criterion is met, the connection is blocked. The invention provides that it is checked as an overheating criterion (S) whether a temperature (T) of the precharge resistor (32) is above a predetermined threshold value (S), the temperature (T) being determined indirectly on the basis of a thermal model (34). of the precharge resistor (32) is determined and the model (34) receives current readings of the current (35) detected as an input parameter at different times.