Method for securing in particular safety-relevant loads in a motor vehicle

A method for securing safety-relevant loads in a motor vehicle, including at least one main path which is arranged between a sub-on-board electrical system for at least one safety-relevant load of the motor vehicle and another sub-on-board electrical system for at least one non-safety-relevant load, the sub-on-board electrical system for the safety-relevant load being supplied with power by an energy store, the main path including at least one switch, the main path further including at least one detector configured to detect a current flowing through the main path, at least one additional path being provided which is connected in parallel with the main path, and the additional path having at least one switch, the method comprising the following steps:

• opening the main path upon detection of a critical state, the critical state including:
• (i) an overcurrent and/or (ii) an undervoltage or overvoltage, on the sub-on-board electrical system for the safety-relevant load, the additional path being closed or kept closed while the main path is open;
• and
• subsequently reopening the additional path,
• wherein, when the critical state is detected, a countermeasure is initiated and/or the main path is closed or remains closed until a fuse that secures the non-safety-relevant load has burned through.

A method for securing safety-relevant loads in a motor vehicle, including at least one main path which is arranged between a sub-on-board electrical system for at least one safety-relevant load of the motor vehicle and another sub-on-board electrical system for at least one non-safety-relevant load, the sub-on-board electrical system for the safety-relevant load being supplied with power by an energy store, the main path including at least one switch, the main path further including at least one detector configured to detect a current flowing through the main path, at least one additional path being provided which is connected in parallel with the main path, and the additional path having at least one switch, the method comprising the following steps:

• opening the main path upon detection of a critical state, the critical state including:
• (i) an overcurrent and/or (ii) an undervoltage or overvoltage, on the sub-on-board electrical system for the safety-relevant load, the additional path being closed or kept closed while the main path is open;
• and
• subsequently reopening the additional path,
• wherein a closing of the main path for a burning-through of a fuse that secures the non-safety-relevant load takes place during a driving operation of the motor vehicle, when no critical state has been detected.

A method for securing safety-relevant loads in a motor vehicle, including at least one main path which is arranged between a sub-on-board electrical system for at least one safety-relevant load of the motor vehicle and another sub-on-board electrical system for at least one non-safety-relevant load, the sub-on-board electrical system for the safety-relevant load being supplied with power by an energy store, the main path including at least one switch, the main path further including at least one detector configured to detect a current flowing through the main path, at least one additional path being provided which is connected in parallel with the main path, and the additional path having at least one switch, the method comprising the following steps:

• opening the main path upon detection of a critical state, the critical state including:
• (i) an overcurrent and/or (ii) an undervoltage or overvoltage, on the sub-on-board electrical system for the safety-relevant load, the additional path being closed or kept closed while the main path is open;
• and
• subsequently reopening the additional path,
• wherein the additional path for charging an intermediate circuit capacitor is closed during an initial start-up of the motor vehicle, and/or after a certain period of time after the charging of the intermediate circuit capacitor, the main path is closed.

A method for securing safety-relevant loads in a motor vehicle, including at least one main path which is arranged between a sub-on-board electrical system for at least one safety-relevant load of the motor vehicle and another sub-on-board electrical system for at least one non-safety-relevant load, the sub-on-board electrical system for the safety-relevant load being supplied with power by an energy store, the main path including at least one switch, the main path further including at least one detector configured to detect a current flowing through the main path, at least one additional path being provided which is connected in parallel with the main path, and the additional path having at least one switch, the method comprising the following steps:

• opening the main path upon detection of a critical state, the critical state including:
• (i) an overcurrent and/or (ii) an undervoltage or overvoltage, on the sub-on-board electrical system for the safety-relevant load, the additional path being closed or kept closed while the main path is open;
• and
• subsequently reopening the additional path,
• wherein an evaluation of a direction of current flowing between the two sub-on-board electrical systems is carried out and/or the main path in an undervoltage critical state is opened only when a current from the sub-on-board electrical system having the safety-relevant load flows into the further sub-on-board electrical system having the non-safety-relevant load.