Simulation of Distance Relay for Load Encroachment Alleviation with Agent Based Supervision of Zone3

Mohamed Badr, Nabil Abassy, Emtethal Abdallah


Cascaded tripping of power lines due to mal-operation of zone-3 distance relays has been one of the main causes of many previous blackouts worldwide. Encroachment of load into zone-3 characteristics during stressed system operation conditions is a basic factor for such mal-operation of the relays. By improving the operation of zone-3, it is possible to prevent mal-operations so that cascaded line tripping can be avoided. For proper study of the behavior of distance relay during faults and load encroachment phenomenon, we must build a model of distance relay, so in this paper a modeling study of distance relay is implemented using MATLAB/Simulink program. However, this model is distinguished from previous models that, examines in detail the third zone of distance relay. Many cases are simulated with changing line loading and fault location to ensure the capability of the relay to detect the fault and thus the maximum load ability limit of distance relay is obtained. In order to prevent cascading events caused by hidden failures in zone-3 relays, agent based relay architectures have been suggested in the recent past. In such architectures each zone-3 relay contains agents that require communication with other agents at various relevant relays in order to distinguish a real zone-3 event from a temporary overload. In this paper, a local master agent is consulted by all zone-3 agents before a tripping decision is made. The master agent maintains a rule base which is updated based on the local topology of the network and real time monitoring of the status of other relays and circuit breakers. Cisco Packet Tracer program is used for running communication network simulations. The result of the simulation indicate that the time estimated to send and receive a packet data unit (PDU) message between one relay to anther can satisfy the communication requirement for the proposed scheme with fiber media.


Distance Relay, Load Encroachment, Hidden Failure, Cascading Blackouts; Agents, Communication; TCP/IP

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A. G. Phadke and J. S. Thorp, "Computer relaying for power systems", In second edition, Research Studies Press Ltd and John Wiley & Sons, 2009.

DamirNovosel, Miroslav M. Begovic, and VahidMadani, "Shedding light on blackout" ,IEEE Power and Energy Magazine, January/February 2004 pp. 32-43.

Thomas L. Baldwin, Magdy S. Tawfik and Miles McQueen, “Contingency Analysis of Cascading Line Outage Events", Power Systems Conference, March 2011.

Swapnil Sharma, JagdishBichve, and YuvrajsinhBharthania, " Performance analysis of Mho relay characteristics using the PSCAD", International Journal of Advance Engineering and Research Development, Volume 2, Issue 1, January -2015,pp. 103-110.

SurachetTamronglak, "Analysis of power system disturbances due to relay hidden failures", Ph.D. Dissertation, Virginia Polytechnic and State University, Blacksburg, Virginia, March 1994.

HOROWITZ S., PHADKE A, "Third zone revisited", IEEE Transaction Power Delivery, 2006, 21, (1), pp. 23–29.

"Final Report on the August 14, 2003 Blackout in the United States and Canada: Causes and Recommendations"[Online]. U.S.-Canada Power System Outage Task Force, 2004 Available:

H. Wang and J. Thorp, " Optimal locations for protection system enhancement: a simulation of cascading outages", Power Delivery, IEEE Transactions on, October 2001,pp. 528-533.

A. G. Phadke, "Hidden failures in electric power systems", International Journal of Critical Infrastructures, January 2004, pp.64-75.

J. Thorp and A. Phadke, "Protecting power systems in the post-restructuring era", Computer Applications in Power, IEEE, 12(1), PP. 33-37, January 1999.

S. Garlapati, H. Lin, S. Sambamoorthy, S. Shukla, and J. Thorp. ,"Agent based supervision of zone 3 relays to prevent hidden failure based tripping", in Smart Grid Communications (Smart Grid Comm), 2010 First IEEE International Conference on, October, 2010, pp.256 -261.

L. C. Wu, C.W. Liu and C. S Chen, "Modeling and testing of a digital distance relay using Matlab/Simulink", IEEE 2005.

MuhdHafiziIdris, Surya Hardi, MohdZamriHasan, "Teaching distance relay using matlab/simulink graphical user interface", Malaysian Technical Universities Conference on Engineering & Technology, 2012.

Yashasvi, Vidushi, Ramesh, "Simulation of mho characteristics for transmission line protection using PSCAD" ,IJREAS, Volume 2, Issue 2 ,February 2012.

Power System Relay Commitee Working Group, "Application of overreaching distance relays", 2009.

System Protection and Control Task Force of the North American Electric Reliability Council, “Methods to Increase Line Relay Laod ability,” June 7, 2006. [Online] Available:

G. E. Digital Energy, "D90Plus line distance protection", GE Digital Energy, 1.8 edition, 2012.

Alstom, "MICOM Mho P446 Fast Multifunction Distance Protection Relay", Alstom, 2011.

VishvadeepJ.Dhawale, Vishal Dake and Prafulla A.Desale, "Blocking the Distance Relay 3rd Zone Operation during Power Swings by DTLR Enhancement in MATLAB/Simulink", International Journal of Electronic and Electrical Engineering. ISSN 0974-2174 Volume 7, Number 7, 2014, pp. 757-765.

ShravanGarlapati, Hua Lin , Andrew Heier, Sandeep K. Shukla, and James Thorp, "A hierarchically distributed non-intrusive agent aided distance relaying protection scheme to supervise Zone 3", Electrical Power and Energy Systems,2013 , pp 42–49.

Hua Lin, SanthoshkumarSambamoorthy, SandeepShukla, James Thorp, LamineMili "AD-HOC vs. supervisory wide area backup relay protection validated on power/network co-simulation platform", proceedings of the 17th power systems computation conference, Stockholm, Sweden, August 22-26,2011



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