DIN EN 50549-2:2026-01

This document deals with the technical requirements for generating plants that operate directly on the medium voltage distribution network and are classified as Type B. It regulates safe, network compatible parallel operation of such plants with the public network. In particular, the scope of application covers protective functions such as voltage and frequency monitoring, behavior in the case of network disturbances such as voltage dips and frequency variations, the capacity to provide reactive power, and communication with the network operator via suitable interfaces. The aim is to ensure the stability and safety of the medium voltage network even with decentralized feed-in. Restrictions apply insofar as the standard does not apply to generating plants that operate exclusively in isolation or are subject to the network connection rules for Type C and Type D plants. These larger plants are subject to the requirements of the transmission networks operators and are dealt with in other sets of regulations such as VDE-AR-N 4120. Plants connected to the low voltage network are also not covered by this standard and instead fall under EN 50549-1. The standard differs from DIN EN 50549-2 (VDE 0124-549-2):2020-10 as follows: a) a requirement for immunity to phase shifts has been introduced; b) the requirement with regard to ROCOF immunity for synchronous and non-synchronous generation technology has been harmonized; c) FRT for Type A has been changed from a recommendation to a requirement; d) further details have been specified for EESS in the event of overfrequency. Typical application examples for EN 50549-2/A1 include large ground-mounted photovoltaic systems that feed directly into the medium voltage network, wind turbines in rural areas with medium voltage connections, combined heat and power plants in industrial parks, and battery storage systems used for network support and to provide control energy. Hybrid generating systems that combine different technologies and share a common medium voltage connection fall under this standard as well.