What situation applies according to this traffic sign?

You are correct that this speed limit applies between 10 pm (22:00) and 6 am (06:00).

This sign shows a speed limit of 30 km/h combined with a supplementary plate reading "22-6h Lärmschutz," which means the speed restriction is specifically for noise protection during nighttime hours. Outside these hours, the general speed rules apply, and the 30 km/h limit does not need to be observed.

The purpose of this rule is to reduce noise pollution in residential areas during night rest periods. It applies to all vehicles without exceptions for electric vehicles or other types.

Remember, if you see a time range on an additional sign under a speed limit, the restriction is only active during those times. This helps you adapt your speed accordingly depending on the time of day.