ČSN EN 50549-2

This document specifies the technical requirements for the protection functions and the operational capabilities for generating plants, intended to operate in parallel with MV distribution networks. For practical reasons this document refers to the responsible party where requirements have to be defined by an actor other than the DSO, e.g. TSO, member state, regulatory authorities according to the legal framework. Typically the DSO will inform the producer about these requirements. The requirements of this document apply, irrespective of the kind of energy source and irrespective of the presence of loads in the producer's network, to generating plants, generating modules, electrical machinery and electronic equipment that meet all of the following conditions: - converting any energy source into AC electricity; - generating modules capacity of type B or smaller according to COMMISSION REGULATION (EU) 2016/631 while considering national implementation for the decision regarding power limits between A and B types and B and C types; - connected to and operated in parallel with an AC MV distribution network. If generating modules of different type (A or B) are combined in one plant, different requirements apply for the different modules based on the type of each module. Unless specified otherwise by the DSO and the responsible party, generating plants with a maximum apparent power up to 150 kVA can, as alternative to the requirements of this document, comply with EN 50549 1. A different threshold may be defined by the DSO and the responsible party. This document recognizes the existence of specific technical requirements (e.g. grid codes) of the DSO or another responsible party within a member state and these must be complied with. Excluded from the scope are the selection and evaluation of the point of connection; power system impact assessment e.g. assessment of effects on power quality, local voltage increase, impact on line protections operation; connection assessment, the set of technical verifications made as part of the planning of the connection; island operation of generating plants, both intentional and unintentional, where no part of the distribution network is involved; four-quadrant rectifier of drives feeding breaking energy back into the distribution network for limited duration with no internal source of primary energy; uninterruptible power supply with duration of parallel operation limited to 100 ms; requirements for the safety of personnel as they are already adequately covered by existing European Standards and the connection of a generating unit, module or plant into a DC network