How to nuisance trip distributed generation

Distributed generation (DG) interconnection protection must be secure to allow the DG to operate in parallel with utility distribution systems. It also must reliably disconnect the DG from the utility distribution system for a variety of reasons such as: loss of utility supply to the feeder (anti-islanding), shunt faults on the utility system and abnormal operating conditions (including open-series events). Additionally, the system should provide restoration elements. Most protection elements are applied to trip the DG off the distribution system in less than one second, and often much faster (10-30 cycles). These tripping times are mandated in DG interconnection standards, and are generally not open to change. Events can occur on the system and within the DG facility, however, that may lead to nuisance trips. These trips may occur due to certain protection elements being set with a tolerance that is too close, combined with an interplay of events that include power surges from cycling loads within a DG facility or faults within a DG facility that should be cleared by other means. We explore these in scenarios labeled as "opportunities" for nuisance tripping of the DG facility. Specific setting examples are not provided, as they are beyond the scope of this paper, but general concepts and possible solutions are discussed to mitigate nuisance tripping.

[1]  Robert C. Rosaler Standard Handbook of Plant Engineering , 1983 .

[2]  C. J. Mozina Interconnect protection of dispersed generators , 2001, 2001 IEEE/PES Transmission and Distribution Conference and Exposition. Developing New Perspectives (Cat. No.01CH37294).