Performance Evaluation of Power Differential and Sensitivity Based Protection for Active Distribution Systems

Abstract

Protection performance is characterized by qualities that include selectivity, speed, sensitivity and stability. Generally, selectivity and speed present conflicting requirements on the protection design, as do sensitivity and stability requirements. The integration of distributed generation (DG), in particular at the distribution level, further compromises satisfactory achievement of these performance qualities. A recent paper by the authors introduced a protection algorithm based on active power differential and sensitivity analysis (APdSA) for the protection of active distribution systems and microgrids. This paper investigates the performance characteristics of this algorithm with respect to selectivity, sensitivity, stability, and speed. It is shown that, with an important modification to the protection zoning arrangement, the APdSA algorithm is able to selectively clear faults in a DGintegrated distribution system with high sensitivity, stability, and speed, with more than 95% reach over a wide range of fault resistances. The algorithm is also tolerant to communication failure.