State description of cyber-physical energy systems

Marcel Klaes,Hermann De Meer,Sebastian Lehnhoff,Jonas Haack,Christian Rehtanz,Martin Braun,Martin Lindner,Anand Narayan,Amit Dilip Patil

doi:10.1186/s42162-020-00119-3

Abstract

The integration of ICT into power systems has increased the interdependencies between the two systems. The operation of power system depends on several ICT-enabled grid services which manifest the interdependencies. ENTSO-E system state classification is a tool that is widely used by operators to determine the current operational state of the power system. However, it does not adequately describe the impact of ICT disturbances on the operation of the power system. Despite their interconnections, the operational states of both systems have been described separately so far. This paper bridges the well-established ENTSO-E systems state classification with an ICT system state classification, forming a new model considering the state classification of the ICT-enabled grid services. The model is developed by first identifying the ICT-enabled services, remedial actions and the respective performance requirements that are required by the power system. Then the states of these services are specified based on the supporting ICT system. The resulting joint state description shows how performance degradation of ICT-enabled services (introduced by disturbances) can affect the operation of the interconnected power system. Two case studies of such ICT-enabled services, namely state estimation and on-load tap changer control, are investigated in terms of how their operational states affect the states of the power system. A third case study highlights the interdependencies that exist between the services. These case studies demonstrate the interdependencies that exist between power and ICT systems in modern cyber-physical energy systems, thus highlighting the usage of a unified system state description.

Highlights

The decarbonisation of Power Systems (PS) has paved the way for smart grids with high penetration of Distributed Energy Resources (DERs), which are geographically distributed across the system
Two case studies of such Information and Communication Technologies (ICT)-enabled services, namely state estimation and on-load tap changer control, are investigated in terms of how their operational states affect the states of the power system
These case studies demonstrate the interdependencies that exist between power and ICT systems in modern cyber-physical energy systems, highlighting the usage of a unified system state description

Summary

Introduction

The decarbonisation of Power Systems (PS) has paved the way for smart grids with high penetration of Distributed Energy Resources (DERs), which are geographically distributed across the system. The smart grid as a safety-critical infrastructure should continuously and reliably provides electricity to its customers For this purpose, system operators use a set of grid services such as ancillary services. In case of contingencies in PS, these grid services provide remedial actions to mitigate the impact of the contingencies and restore vital PS parameters such as voltage, frequency and power reserves to their corresponding normal operational security limits. These grid services assist the operators in economically optimising the operation of the system (e.g., optimising generation costs while meeting a certain demand). In addition to the transmission system, the distribution systems requires more active management and coordination due to the increase in DERs such as wind and PV power plants, electric vehicles, fuel cells and combined heat and power; which are more prominent on the distribution side

Objectives

Conclusion