An effective framework to Solve Protection Coordination Issues in DER-Enabled Smart Microgrids

New advances in microgrid systems have led to complex evolution of such small system that sometimeseven act as traditional distribution systems and an interface between service providers and end users. In fact,electrical power systems are undergoing a complex, lengthy and transformation as new technologies areintroduced. More precisely, these technological advances in microgrid systems as a remote system and/or aninterface between service providers and end users have led to smart microgrid systems. While thesetechnological advancements have improved the efficiency and the service quality, they require carefulalteration especially in protection and operation schemes. The technological advancements have allowed themicrogrids to have flexible configurations based on the strategy taken for more economical operation of suchsystems. On the other hand, protective devices in a microgrid are usually set for a critical level of fault currentcalculated for a certain configuration. Therefore, a flexible configuration may jeopardize the protectioncoordination. In a smart microgrid with Distributed Energy Resources (DERs) this issue is more pronounced.This paper presents a framework to find the location and size of Fault Current Limiters (FCLs) to reduce thefault currents and to cope with the issue of protection coordination failure in smart microgrids enabled withDERs. The problem explained so far is a mixed integer nonlinear programming (MINLP) problem andHarmony Search Algorithm (HSA) is used as an effective meta-heuristic optimization algorithm to solve theproblem. The proposed framework is tested on IEEE 03-bus system to show how protection coordination canbe held applying the proposed framework for a multiple-configuration microgrid with the grid connectioncapability.

کلیدواژه ها:

Distributed energy resources ، fault current limiter ، harmony search ، protection coordination ، smart microgrid