Decentralized TSO-DSO coordination for voltage regulation purposes based on renewable energy sources management – Sensitivity and robustness analyses

Copyright © 2022 The Author. The increasing penetration of Renewable Energy Sources (RES) in distribution networks has led traditional voltage regulation to their boundaries. In order to develop advanced techniques for voltage control in this new context, an adequate and real-time coordination and communication between Transmission System Operators (TSOs) and Distribution System Operators (DSOs) is needed. In this paper, a decentralized TSO-DSO coordination approach for scheduling and deploying optimal reactive power exchanges in the DSO's boundary for improved voltage control in the TSO's networks is proposed. The proposed approach is implemented via a standardized Business Use Case (BUC). The interoperability between the TSO, the DSO, and other stakeholders is solved by designing and developing the BUC within the framework of the International Electrotechnical Commission (IEC) Common Information Model (CIM) family of standards IEC61970, IEC61968, and IEC62325. In view of the lack of pilot tests in the field, the proposed standardized BUC is demonstrated on real-world Slovenian TSO's and DSO's networks. The simulation experiments presented in this paper are twofold. On one hand, the proposed data exchange mechanism based on the standardized BUC demonstrates the feasibility of successfully exchanging data between the TSO, the DSO, and other stakeholders, such as the Significant Grid Users (SGUs) and Meter Operators, as a CIM Common Grid Model Exchange Standard (CGMES) format. On the other hand, the capability of the proposed decentralized TSO-DSO coordination approach to regulate the High Voltage (HV) by managing the reactive power injected by different RES, such as capacitor banks and different Distributed Generators (DGs), viz. hydropower, Photovoltaic (PV), and thermal (co-generation) units, is validated via sensitivity and robustness analyses for different network topologies, DGs’ operating scenarios, and capacitor banks’ sizes and locations. The simulation results show that the proposed approach can manage DGs toward contributing additional (positive or negative) reactive power to reduce the voltage deviations in the grid, improve the power quality at the DSO's boundary by reducing the flow of reactive power from the TSO's to the DSO's networks and vice versa, and keep the HV voltage within safe values. Unfortunately, this is not the case for the capacitor banks, where the capability of the proposed approach to manage their injected reactive power to regulate the HV voltage is highly dependent on their sizes and location, being necessary to be studied on a case-by-case basis.This paper is based on TDX-ASSIST project that has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 774500

Design of Interoperable Communication Architecture for TSO-DSO Data Exchange

European Union’s Horizon 202

Groundwater level oscillation analysis in shallow alluvial aquifers in Pomurje, NE Slovenia

Systematic hydrologic monitoring of groundwater quantity at the national level in Slovenia has been ongoing since 1952. An insight into long-term groundwater level data enables us to delineate parts of aquifers with similar groundwater level oscillation properties as well as to identify changes of those properties in time. We used variety of statistical methods to identify long-term behaviour of groundwater level oscillation of groundwater body (GWB) Murska kotlina. Results showed that fluctuation of groundwater level in time reflect complex set of events that originate in natural or anthropogenic interferences. Using percentile analysis in combination with cluster analysis, we were able to isolate areas with a related groundwater fluctuation. Results of long-term data trends analyses of monthly groundwater level showed the impact of the research area climate on long-term and seasonal groundwater level fluctuation. In addition to natural causes, by performing trend analysis on groundwater level data, we were able identify some human induced interventions into the environment made in the past

INFORMATION SYSTEMS INTEGRATION IN THE CONCEPT OF SMART GRID

V konceptu pametnih elektroenergetskih omrežij je ključno izmenjevanje informacij med različnimi sistemi, tako znotraj podjetij, kot z zunanjimi partnerji. Integracija informacijskih sistemov zahteva poleg interoperabilnosti na nivoju komunikacijskih protokolov tudi razumevanje pomena informacij, oziroma interoperabilnost na semantičnem nivoju, ustrezno integracijsko arhitekturo ter standardizacijski okvir. Brez tega, koncepta pametnih omrežij ni možno učinkovito izvesti. Čeprav je standardizacijski okvir že na voljo, je uvajanje semantičnih tehnologij za integracijo sistemov v elektroenergetska podjetja zanje novost, ki zahteva veliko razvojnih, implementacijskih in organizacijskih naporov. V nalogi je predstavljena problematika integracije v okviru pametnih omrežij, standardizacijski okvir ter skladno z njim predlagan koncept integracije informacijskih sistemov za ključne primere uporabe.In the concept of smart grid information exchange between different systems, both within companies and with external partners, is of key importance. An effective integration of IT systems requires in addition to interoperability at the level of communication protocols also interoperability at the semantic level, an appropriate integration architecture and a standardisation framework. Without this, the concept of smart grid cannot be effectively implemented. Although the standardisation framework is already available, the implementation of semantic technologies for systems integration in the power utility companies is new to these companies. Extensive development, implementation and organisational efforts will be required. The work presents the issues of information systems integration within the scope of smart grid and proposes integration concepts for most common use cases which are aligned with the European Smart Grid Reference Architecture

Connectedness of configuration spaces of robot manipulators

S topološkega vidika predstavimo definicije robotske naprave, konfiguracijskega prostora in kinematične preslikave. Podamo definicijo singularnih točk kinematične preslikave in podrobneje obravnavamo razreda zaporednih in vzporednih robotskih naprav. Kinematično funkcijo zaporednih naprav izračunamo s pomočjo Denavit-Hartenbergovih parametrov in opišemo njeno množico singularnosti. Utemeljimo pogoje pod katerimi singularne točke in singularne vrednosti ločijo konfiguracijski prostor zaporednih naprav. Za analizo delovanja vzporednih naprav uvedemo pojma sestavnega načina in razširjenega konfiguracijskega prostora. Z uporabo izreka o implicitni preslikavi določimo lokalno kinematično preslikavo vzporednih naprav.We present definitions of a robot manipulator, configuration space and kinematic map from a topological viewpoint. The classes of serial and parallel manipulators are studied to determine their kinematic mapping and its singular points. The kinematic mapping of serial manipulators and its singular points are computed using Denavit-Hartenberg parameters. We study the conditions under which singular points and singular values separate the configuration space of serial manipulators. For analysis of parallel manipulators the concepts of assembly modes and extended configuration space are presented. We determine the local kinematic mapping of parallel manipulators using the implicit function theorem