Conceptualizing the protection properties of DC networks: Functional requirements on DC protection systems

Abstract:
Protection against faults is one of the major challenges to the widespread integration of DC- and hybrid AC/DC-grids. A structured planning process for protection systems is necessary with regard to standardization. This paper closes a gap in the planning process at concept level by structuring the stakeholder analysis. The needs of all stakeholders must be trans-lated into a form which supports the selection of a protection system. Protection systems are characterized according to CENELEC (CLC/TS 50654-1) using the concepts of “continued operation”, “temporary stop” and “permanent stop”. This paper creates a link between possible stakeholder needs and the CENELEC approach. A catalogue of different require-ments on the protection system is proposed which may be defined by stakeholders in collaboration with the protection designer. Both external requirements arising from the connection to other grids and internal requirements originating from the DC grid itself are considered.