Distributed generation and its impact on power grids and microgrids protection

The National Institute of Standards and Technology, NIST, is assigned by the US Department of Energy, DoE, to drive Smart Grid developments and harmonization efforts in the power industry. Distributed Generation has been identified as one of the important areas for the Smart Grid developments. Multiple generation sources, bi-directional power flow, power flow time co-ordination and management bring significant benefits and challenges for the existing and emerging power grids and microgrids. In particular, the effect of distributed generation on protection concepts and approaches needs to be understood, and accounted for. This paper describes distributed generation concepts, applications and scenarios. Benefits and challenges are discussed and analyzed on a number of real life examples. Special considerations are provided on ensuring security and dependability, as well as on protection parameterization and coordination.