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.
Grid-driven tool for renewables integration based on nodal capacity allocation
Over the last years, most countries in the world are facing a growing integration of renewable energy sources in their power networks due to the continuous effort on decreasing their carbon footprint. This increasing penetration of renewable energy sources led to the emergence and consequent grow of distributed generation units. From a network planning and growth perspective, the increase of producing centers has different challenges. Additionally, system operators must know and sometimes publish the grid capacity to receive new generation units. Taking this into account, this paper presents a tool that can be used to determine the capacity for reception of new energy sources in the different grid nodes. The tool uses genetic algorithms and power systems analysis software to perform this nodal capacity allocation and its validation is presented through the application of a case study.
Frequency selective surface design for blinds applications
In this paper, the reconfigurable blind structure with frequency selective surfaces(FSS) for the building applications are presented. Frequency transmission characteristics for different angles of the proposed blind-FSSs are investigated and verified through simulation and measurement. The simulation results show that we can implement the reconfigurable blind-FSS for multiband wireless applications. To verify the proposed paper, two kinds of blind-FSSs, crossed dipole FSS and circular ring FSS are fabricated and measurements are performed for different angles. The proposed structure in this paper which is very simple, can be easily applied to any planar surface for wireless security applications at low cost.