Search NASA⌕ Search

Engineering topics

Kou, Gefei

Publications and source records attributed to Kou, Gefei.

6 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Protection of Radial Circuits with High Penetration Distributed Photovoltaics

The paper addresses the shortcomings of distribution protection systems as distribution level photovoltaic installations as well as other inverter based distributed resources are added to the system. Several protection schemes have been evaluated, including distance-based, estimation-based and learning-based. The paper summarizes the results and provides recommendations.

distance protection, radial distribution feeders, ↗
DOE OSTI2019

Fault Characteristics of Distributed Solar Generation

Inverter-based distributed energy resources (DERs) are characterized with low fault current and negligible amount of negative and zero sequence currents. Understanding DER's fault characteristics is important for fault analysis and protective relay setting. Despite the abundant work on DER modeling, few research studies have been done to analyze DER's fault behaviors during actual fault events. Our work explores recorded fault events collected by Dominion Energy. Fault magnitude, angle, and sequence components are analyzed to show that actual DER fault response may differ from previous understandings.

14 SOLAR ENERGY↗
DOE OSTI2018

Non-Invasive Identification of Inertia Distribution Change in High Renewable Systems Using Distribution Level PMU

Here, this letter proposed an approach to identify the change of inertia distribution in high renewable power systems. Using the footprints of electromechanical wave propagation at the distribution level, this approach provides a new and non-invasive way to aware the system inertia distribution for primary frequency response. Actual measurements and high renewable dynamic models validated effectiveness of the approach.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2016

Virtual interconnection platform initiative scoping study

Due to security and liability concerns, the research community has limited access to realistic large-scale power grid models to test and validate new operation and control methodologies. It is also difficult for industry to evaluate the relative value of competing new tools without a common platform for comparison. This report proposes to develop a large-scale virtual power grid model that retains basic features and represents future trends of major U.S. electric interconnections. This model will include realistic power flow and dynamics information as well as a relevant geospatial distribution of assets. This model will be made widely available to the research community for various power system stability and control studies and can be used as a common platform for comparing the efficacies of various new technologies.

97 MATHEMATICS AND COMPUTING↗