DKE German Commission for Electrical, Electronic & Information Technologies of DIN and VDE
DIN VDE V 0126-1-1
; VDE V 0126-1-1:2013-08
Automatic disconnection device between a generator and the public low-voltage grid
Selbsttätige Schaltstelle zwischen einer netzparallelen Eigenerzeugungsanlage und dem öffentlichen Niederspannungsnetz
Procedure
VN
Overview
Like on the higher voltage levels, the generators feeding into low-voltage grids will be involved in static voltage level maintenance in the future. Therefore, they shall contribute to voltage level maintenance in low-voltage grids during normal mains operation. For this reason, application guide VDE AR-N 4105 "Generators connected to the low-voltage distribution network - Technical requirements for the connection to and parallel operation with low-voltage distribution networks" has been prepared by FNN and incorporated into the VDE body of standards in August 2011. This resulted in modifications for the mains connection of PV systems which also effect DIN V VDE V 01261-1 (VDE V 0126-1-1). Application rule VDE-AR-N 4105 summarizes the main points which shall be considered for termination on the low-voltage grid so the security and reliability of the mains operation are maintained in accordance with the provisions of the energy industry law also with an increasing proportion of decentralized generators and the limit values of voltage quality formulated in DIN EN 50160 can be met. For this reason DIN V VDE 0126-1-1 (VDE V 0126-1-1) had to be adapted to VDE-AR-N 1405. The adaptation was carried out so all requirements specified in VDE-AR-N 4105 are not repeated in DIN V VDE V 0126-1-1 (VDE V 0126-1-1). If required, reference was made in the individual clauses of DIN V VDE V 0126-1-1 (VDE 0126-1-1) to relevant clauses of VDE AR-N 4105. The same applies to type testing. In this case the adaption was also carried out so all requirements specified in DIN V VDE V 0124-100 (VDE V 0124-100) "Grid integration of generator plants - Low-voltage - Test requirements for generator units to be connected to and operated in parallel with low-voltage distribution networks" are not repeated in DIN V VDE V 0126-1-1 (VDE V 0126-1-1). Thus, if necessary, the individual clauses of DIN V VDE V 0124-100 (VDE 0126-1-1) refers to relevant clauses of DIN V VDE V 0124-100 (VDE V 0124-100). The automatic disconnection device is used as a safety interface between the generator and the public low-voltage distribution net and serves as a substitute for a disconnecting switch accessible at all times by the distributing network operator. It prevents the unintentional supply of electrical energy from the generator into a subnetwork disconnected from the rest of the distribution grid (islanding), thereby offering additional protection to the measures specified in DIN VDE 0105-100 (VDE 0105-100), 6.2 to - operating staff, against voltage in the disconnected subnetwork - equipment, against inadmissible voltages and frequencies - consumers, against inadmissible voltages and frequencies - equipment, against the feed of faults by the generator. In case of errors in the low-voltage grid, the automatic disconnection device does not protect the generator from - impermissible overload and - impermissible short circuits. This protection shall be ensured otherwise in accordance with DIN VDE 0100-712 (VDE 0100-712), DIN VDE 0100-430 (VDE 0100-430) and DIN VDE 0100-530 (VDE 0100-530). The responsible committee is K 373 "Photovoltaische Solarenergie-Systeme" ("Solar photovoltaic energy systems") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.
