Modeling and Integrating PV Stations into IEC 61850 XMPP Intelligent Edge Computing Gateway

Abstract

Distributed energy resources (DERs) are being widely interconnected to electrical power grids. The dispersed and intermittent generational mixes bring technical and economic challenges to the power systems in terms of stability, reliability, and interoperability. In practice, most of the communication technologies in DER are provided by proprietary communication protocols, which are not designed for the prevention of cyber security over a wide area network, and methodology of DER integration is not unified. This has made it technically difficult for power utilities and aggregators to monitor and control the DER systems after they are interconnected with the electrical grids. Moreover, peer to peer communication between DER systems as well as local intelligent computation is required to reduce decision latency and enhance the stability of the smart grid or microgrid. In this paper, the first, novel architecture of IEC 61850 XMPP (extensible messaging and presence protocol) of the edge computing gateway, involving advanced concepts and technologies, was developed and completely studied to counter the abovementioned challenges. The results show that the proposed architecture can enhance the DER system’s effective integration, security in data communication and transparency for interoperability. The novel and advanced concepts involve first modeling the topology of the photovoltaic (PV) station to IEC 61850 information models according to the IEC 61850-7-4 logical nodes and the DER-specific logical nodes defined in IEC 61850-7-420. This guarantees the interoperability between DER and DER, DER and utility and DER and the energy service operator. The second step was to map the information models to IEC 61850-8-2 XMPP for the specific communication protocol in DER applications. XMPP protocol, a publish/subscribe communication mechanism, is recommended in DER applications because of its characteristics of cybersecurity and authenticated encryption. After that we enabled the edge computing capability for data processing and the analytics of the DER side for time-critical missions. The aggregated data was then sent to the control center in the cloud. By applying the edge computing architecture, the system reduced decision latency, improved data privacy and enhanced security. The goal of this paper was to introduce the practical methodologies of these novel concepts to academics and industrial engineers.