Search

In this work, functions of type-2 fuzzy numbers are analyzed. For the special case of interval type-2 fuzzy numbers, the type-2 membership function of the output variable is calculated using the lower and upper membership functions of the input variables and the vertex method. This procedure is used in an application where the type-2 fuzzy fault currents of an electric distribution system are calculated. The results are shown and the advantages of the approach are discussed. [ABSTRACT FROM AUTHOR]

In Part I of this two-paper set, the inference of the operative configuration (OC) in real lime has been analyzed. This Part II presents an approach to infer the OC in extended real time, by proposing a mathematical model based on fuzzy relation equations and fuzzy abductive inference. This model sets a methodological framework to integrate the realtime data from SCADA, the qualitative data supplied by expert operators, and the extended real-time data (customer trouble calls) from CIS. In this way, all the knowledge available is used, and the results are dynamically improved as more data are received. At every stage, all the plausible alternatives of solution are calculated, and a complete outlook of possible options is obtained. The results from testing the methodology on a real distribution feeder are presented and discussed. [ABSTRACT FROM AUTHOR]

In this first part of a two-paper set, the operative configuration (OC) is defined as the state (closed/open) of the protective and switching devices installed on the medium voltage distribution network. OC identification is fundamental for the outage management and state estimation of these networks, particularly for those with a low level of real-time supervision and control. In these networks, however, it is difficult to obtain the OC with conventional analytical techniques because of the scarcity or unavailability of monitored devices and measuring points. To overcome this, a novel methodology of inference is presented here. Part I develops a real-time approach based on power flow analysis, fuzzy fault currents calculation and rule-based Type-2 Fuzzy Logic Systems. Part II proposes an extended real-time approach based on fuzzy relation equations and fuzzy abductive inference. The performance of the methodology is evaluated on a real distribution feeder, and results are shown and discussed. [ABSTRACT FROM AUTHOR]

The increasing adoption of distributed energy resources (DERs) and smart grid technologies (SGTs) by end-user retail customers is changing significantly both technical and economic operations in the distribution grid. The next-generation retail electricity market will promote decentralization, efficiency, and competitiveness by accommodating existing and new agents through new business models and transactive approaches in an advanced metering infrastructure (AMI). However, these changes will bring several technical challenges to be addressed in transmission and distribution systems. Considerable activities have been carried out worldwide to study the impacts of integrating DERs into the grid and in the wholesale electricity market. However, the big vision and framework of the next-generation retail market in the context of DERs is still unclear. This paper aims to present a brief review of the present retail electricity market, some recent developments, and a comprehensive vision of the next-generation retail electricity market by describing its expected characteristics, challenges, needs, and future research topics to be addressed. A framework of integrating retail and wholesale electricity markets is also presented and discussed. The proposed vision and framework particularly highlight the necessity of new business models and regulatory initiatives to establish decentralized markets for DERs at the retail level as well as advances in technology and infrastructure necessary to allow the widespread use of DERs in active and effective ways. [ABSTRACT FROM AUTHOR]