Grid and System Protection: The Key Role of Protection for Efficiency and Safety of Solar Energy
In accordance with the application rule VDE-AR-N 4105:2018-11, grid and system protection (NA-Schutz) is required in Germany for all generation plants from 30 kW to 135 kW. This protective device plays an important role in the safe integration of solar systems into the power grid and ensures compliance with specified voltage and frequency tolerances, as well as the prevention of islanding.
The NA-Schutz according to VDE-AR-N 4105 continuously monitors the voltage and frequency of the supply network to ensure that they are within the specified tolerances. In the event of deviations, the NA-Schutz safely disconnects the power generation system from the grid within 0.2 seconds. Fault tolerance in this case means that two independently controlled switching elements are connected in series, so that if one switch fails, the function is preserved.