Electricity + Control September 2015

ENERGY + ENVIROFICIENCY

[3] UstunTS,etal.Investigationofmicrogridbehaviourwhileoperatingunder variousnetworkconditions.PresentedattheIEEEInternationalConference on Smart Grid Engineering (SGE 12), UOIT, Oshawa, Canada, 2012. [4] El-Tamaly HH and El-sayed AHM. A new technique for setting calculation of digital distance relays. Power Systems Conference, 2006. MEPCON 2006. [5] OsmanAH,etal.2005.Transmissionlinedistancerelayingusingon-line trainedneural networks. PowerDelivery, IEEETransactions, Volume20. [6] OudalovAandFidigatti A. Adaptivenetwork protection inmicrogrids. More Microgrids Europe. www.microgrids.eu/documents/519.pdf. [7] Ustun TS, et al. 2011. A microgrid protection system with central protection unit and extensive communication. Environment and Electrical Engineering (EEEIC), 2011 10th International Conference. [8] Ustun TS, et al. 2012. Fault current coefficient and time delay as- signment for microgrid protection systemwith central protection unit. Power Systems, IEEE Transactions, Volume PP. [9] Ustun TS, et al. 2011. A central microgrid protection system for networks with fault current limiters. Environment and Electrical Engineering (EEEIC), 10th International Conference 2011. [10]Ozansoy CR, et al. 2009.Object modelling of data and data sets in IEC 61850. Power Delivery, IEEE Transactions, Volume 24. [11]Ozansoy CR, et al. 2009. The application-viewmodel of IEC 61850. Power Delivery, IEEE Transactions, Volume 24. [12]WG17> Introduction to IEC 61850-7-420: Distributed Energy Re- sources (DER) Object Modelling. White Paper, Volume. Ver2. 2009. [13]Ustun TS, et al. 2011. Implementation of Dijkstra’s Algorithm in a Dynamic Microgrid for Relay Hierarchy Detection. Second IEEE International Conference on Smart Grid Communications (SmartGridComm), Belgium. [14]Faria P. 2009. Shortest path with Dijkstra and C#. Available: http:// letmetutoryou.wordpress.com/2009/05/26/shortest-path-with- dijkstra-and-c/

Figure 4: Dijkstra’s Algorithm run for case 1, Path from CB2 to DG4.

Figure 5: Dijkstra’s Algorithm run after new deployments, Path from CB2 to DG6.

Conclusion OO based models are proposed for microgrid modelling. The pro- posed models make it possible to define information data specific to various electrical nodes within a network in terms of connections between the nodes and the devices connected to these nodes. In this manner the changing structure of a particular network can be fol- lowed and the new operating points can be calculated, then updated. After modelling the microgrid according to graph theory, Dijkstra’s algorithm is implemented to find the path from the point of common coupling to different parts of the network. This algorithm extracts the hierarchy of different components in the network. This feature is very crucial for plug and play purposes in electrical networks.

• The lessons learned in distributed control systems are now being applied in power network control. • New algorithms of control are continually evolving as we require more and more ‘intelligence’ in our power networks. • Dijkstra’s algorithm has been shown to be applicable to determining the path from point of common coupling to different parts of the network – enhancing our ability to understand the network operation.

take note

Acknowledgement The author presented this topic at the ICUE conference in Cape Town in 2014.

Taha Selim Ustun received a BE degree in Electrical and Electron- ics Engineering from Middle East Technical University, Turkey in 2007 and a Master of Engineering Science degree from the University of Malaya, Malaysia in 2009. He has a PhD in Electri- cal Engineering from Victoria University, Melbourne, Australia. Currently, he is an Assistant Professor in Electrical Engineering,

References [1] Ustun TS et al. 2011. Recent developments inmicrogrids and exam- ple cases around the world - A review. Renewable and Sustainable Energy Reviews. [2] Lasseter B. Microgrids. IEEE 2001 WM Panel: Role of Distributed Generation in reinforcing the Critical Electric Power Infrastructure.

School of Electrical and Computer Engineering, Carnagie-Mellon University, PA, USA. His research interests are Power Systems Protection, Communication in Power Networks, Distributed Generation, Microgrids and Smartgrids. Enquiries: Email ustun@cmu.edu

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