الفهرس 
Fault types in DC microgridsOnly 14 pages are availabe for public view
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Abstract
The development of microgrids is a growing global trend. Microgrids are increasingly viewed as a way to improve electric service resiliency, reduce costs, increase environmental stewardship, and upgrade service reliability for critical uses. Microgrids can help communities of utility users to achieve key policy goals that can enhance the use of renewable energy. However, the high penetration of renewable energy sources (RESs), such as photovoltaic (PV) and wind turbine (WT) systems, assisted in construction the microgrids (MGs). Using the DC microgrids, as the preferable type of microgrids, offers many advantages. However, DC microgrids are facing big challenges in their control, protection, stability, and standardized efforts. So, the most needed and highly potential is the requirement of DC microgrod protection. An accurate model of the DC microgrids is developed. The model considers RESs, energy storage devices and their power electronic interfaces. The model is modeled using PSCAD/EMTDC software. The maximum power point tracking (MPPT), which is practically implemented with RESs, is built. Moreover, a typical grounding scheme and DC bus configuration are integrated for getting an accurate investigation. The fault analysis provides the behavior of each separate source with its own control during fault events on the DC terminals. The investigation of the fault response for all the integrated units is achieved. The study included complete DC microgrid operation of wind energy system (WES), PV unit and energy storage system (ESS). The fault analysis study will show very valuable results and recommendation that is taken in consideration for the next achievement step of developing a protection scheme. The thesis provids a new protection scheme based on the power & voltage derivatives for the DC microgrid. The proposed protection scheme is working in II decentralized mode which can be applicable for all types of RESs and energy storages, independent of the rating and configuration of DC microgrid. The hypothesis of the new protection scheme is presented. It is based on the profile of power & voltage derivatives. Using this profile, the zones for various fault conditions of renewable sources and energy storage can effectively be discriminated from the normal operation. The relay characteristics are properly set to clearly classify various zones and identify the fault type and also the fault location. Several fault events has been studied with different fault resistance and fault types to ensure the sensitivity and operation speed of the protection scheme. The developed idea is considered as a potential solution for increasing the investigation of DC microgrid without any technical problems in the protection systems.