Agent‐based identification and control of voltage emergency situations

Abstract

Changing dynamics of power systems caused by the migration from conventional to distributed energy sources increase the risk of blackouts due to voltage instability, especially in case of unforeseen network conditions (e.g., (N-k)-cases). To enable a both secure and efficient power supply, novel monitoring and emergency control systems for the identification of voltage emergency situations as well as the execution of control actions are required that react reliably in due time and adaptively in case of changing network situations. This paper presents a distributed agent-based approach to counteract voltage instability that is based solely on local measurements and limited inter-agent communication. Distributed agents located at substations in the (sub-)transmission network monitor distribution and transmission voltages as well as load tap changer positions and are able to autonomously curtail load in case system stability is endangered. The applicability of the approach is demonstrated in a co-simulation environment interfacing the multi-agent system with a dynamic power system simulation. The presented approach allows for an early detection of voltage instability as well as a coordinated execution of available control actions. IntroductionThe large-scale integration of renewable energy sources and the related decommissioning of conventional power plants change the complexity and dynamics of future power grids. Especially in case of (N-k) situations, the risk of regional or large-scale blackouts due to long-term voltage instability has to be carefully assessed. To counteract critical network conditions, novel emergency control concepts acting timely and making use of available measures are essential for maintaining system stability in future power systems [1]. The major challenges for such systems are (i) a reliable reaction in due time, (ii) the adaptability in case of changing network conditions, (iii) the robustness to communication failures, and (iv) the coordinated activation of countermeasures.As an alternative to centralized system integrity protection schemes requiring significant computational effort in case of largescale grids or the comprehensive installation of wide-area monitoring and control systems, as proposed in [2]. is proposed. Future substations will be connected through high speed communication links which allows for distributed controllers communicating between each other. In particular, a Multi-Agent System (MAS) is developed with intelligent agents situated at substations in the transmission and subtransmission network. Agents monitor the trend of local bus voltages, communicate with other agents and decide about corrective control actions autonomously. The developed approach allows for fast detection of an evolving voltage instability after the system is subjected to severe disturbances as well as the autonomous activation of countermeasures in order to restore a stable state of equilibrium with acceptable bus voltages.The paper is structured as follows. First, in Section 2 the...

Enabling hard service guarantees in Software-Defined Smart Grid infrastructures

“…Since it maps higher voltage levels, integration of DERs is considered in terms of adjusted distribution system loads. As shown by several current publications, the Nordic 32 test system is still very relevant for power system analysis today [56,57,58,59]. Further, it is supported by the fact that the Nordic cycles [61] compared to the ICT sector.…”

Εξελιγμένες Μέθοδοι Ανίχνευσης Αστάθειας Τάσης Σε Πραγματικό Χρόνο Και Μέτρα Προστασίας Με Αξιοποίηση Διεσπαρμένων Πηγών

“…Συνέχεια των παραπάνω εργασιών αποτελούν οι[VLG10] και[VLK15], στις οποίες παρουσιάζεται ολοκληρωμένο και αποκεντρωμένο σύστημα προστασίας από κατάρρευση τάσης, ενσωματώνοντας σύστημα άμεσης αποκοπής φορτίου για την προστασία συστήματος από κατάρρευση. Στην εργασία[RWH13] παρουσιάζεται ένα διανεμημένο σύστημα ανίχνευσης αστάθειας τάσης και προστασίας συστήματος βασισμένο σε παραλλαγή της μεθόδου της εργασίας[VVC08]. Η αρχική παραλλαγή παρουσιάζεται στο[WPV17], η οποία εκτιμά την αδυναμία ρύθμισης του ΣΑΤΥΦ από τη μακροπρόθεσμη συμπεριφορά της ελεγχόμενης από το ΣΑΤΥΦ τάσης, χρησιμοποιώντας παλινδρόμηση με αναδρομικά γραμμικά ελάχιστα τετράγωνα.…”