1. Interconnection Protection Issues Protection related problems in the distribution systems due to presence of Distributed Generation

2. Problems when a fault occurs … Islanding Overvoltages Ferroresonance Loss of synchronism Loss of Coordination Sympathetic Trippings

3. Islanding “A condition in which a portion of the utility system that contains both load and distributed resources remains energized while isolated from the remainder utility system” – IEEE Std. 100-2000 Technical and legal concerns when Distributed Generation supply abnormal voltage and frequency to the utility customers

4. Overvoltages

5. Ferroresonance

6. Out of Synchronism Between automatic reclosing intervals, the DGs may no longer be in synchronism with the utility Closing in out of sync generator can result in severe personal and equipment damage

7. Loss of Coordination

8. Sympathetic Trippings

9. Protection Example

10. References A. Zamani, T. Sidhu, and A. Yazdani, "A strategy for protection coordination in radial distribution networks with distributed generators," in Power and Energy Society General Meeting, 2010 IEEE, 2010, pp. 1-8. S. A. M. Javadian, M. R. Haghifam, M. Fotuhi Firoozabad, and S. M. T. Bathaee, "Analysis of protection system’s risk in distribution networks with DG," International Journal of Electrical Power & Energy Systems, vol. 44, pp. 688-695, 1// 2013. K. Kauhaniemi and L. Kumpulainen, "Impact of distributed generation on the protection of distribution networks," in Developments in Power System Protection, 2004. Eighth IEE International Conference on, 2004, pp. 315-318 Vol.1. R. F. Arritt and R. C. Dugan, "Distributed generation interconnection transformer and grounding selection," in Power and Energy Society General Meeting - Conversion and Delivery of Electrical Energy in the 21st Century, 2008 IEEE, 2008, pp. 1-7. P. Barker, "Overvoltage considerations in applying distributed resources on power systems," in Power Engineering Society Summer Meeting, 2002 IEEE, 2002, pp. 109-114 vol.1. C. J. Mozina, "Impact of Green Power Distributed Generation," Industry Applications Magazine, IEEE, vol. 16, pp. 55-62, 2010. "IEEE Recommended Practice for Electric Power Distribution for Industrial Plants," IEEE Std 141-1993, pp. 1-768, 1994. G. Dalke, A. Baum, B. Bailey, J. M. Daley, B. Duncan, J. Fischer, et al., "Risks From Utility Supply Disruption," Industry Applications Magazine, IEEE, vol. 17, pp. 47-56, 2011. D. A. Tziouvaras and H. Daqing, "Out-of-step protection fundamentals and advancements," in Protective Relay Engineers, 2004 57th Annual Conference for, 2004, pp. 282-307. Distributed Generation Technical Interconnection Requirements," Hydro One, 2011