Publication Type:

Journal Article


IEEE Transactions on Smart Grid, Volume 4, Number 3, p.1523-1532 (2013)


Circuit faults, DG penetration level, directional overcurrent relays, Distributed Generation, Distributed power generation, distribution system planners, Faults, IEEE 14-bus systems, IEEE 30-bus systems, Impedance, Indexes, looped distribution systems, mathematical model, meshed distribution systems, nonlinear programming, Optimization, PCI, power distribution faults, power distribution protection, protection coordination, protection coordination index, protection coordination time interval, Relays, Short-circuit currents, two-phase NLP optimization problem


Depending on the capacity, type and location, distributed generation (DG) can have an impact on protection coordination of directional over-current relays for looped distribution systems. In this paper, a new index is proposed, “protection coordination index” (PCI), which can serve as an effective measure when planning the protection of meshed distribution systems with DG. A two-phase non-linear programming (NLP) optimization problem is proposed to determine the PCI by optimally calculating variations in the maximum DG penetration level with changes in the protection coordination time interval. Furthermore, the influence of connecting a DG at a certain location on the system PCIs is examined. The presented analysis is tested on the distribution section of the IEEE 14-bus and IEEE 30-bus systems. The PCI can serve as an efficient index for distribution system planners: (i) to determine the best DG candidate locations for utility owned DG and (ii) to evaluate the impact of a customer owned DG, considering distribution system protection.

Cite this Research Publication

H. H. Zeineldin, Mohamed, Y. A. R. I., Khadkikar, V., and Dr. V. Ravikumar Pandi, “A Protection Coordination Index for Evaluating Distributed Generation Impacts on Protection for Meshed Distribution Systems”, IEEE Transactions on Smart Grid, vol. 4, pp. 1523-1532, 2013.