This paper presents a Monte Carlo approach for reliability assessment of distribution systems with distributed generation using parallel computing. The calculations are carried out with a royalty-free power flow simulator, OpenDSS (Open Distribution System Simulator). The procedure has been implemented in an environment in which OpenDSS is driven from MATLAB. The test system is an overhead distribution system represented by means of a three-phase model that includes protective devices. The paper details the implemented procedure, which can be applied to systems with or without distributed generation, includes an illustrative case study and summarizes the results derived from the analysis of the test system during one year. The goal is to evaluate the test system performance considering different scenarios with different level of system automation and reconfiguration, and assess the impact that distributed photovoltaic generation can have on that performance. Several reliability indices, including those related to the impact of distributed generation, are obtained for every scenario.

This paper presents a bibliographical survey of the work carried out to date on the solid state transformer (SST). The paper provides a list of references that cover most work related to this device and a short discussion about several aspects. The sections of the paper are respectively dedicated to summarize configurations and control strategies for each SST stage, the work carried out for optimizing the design of high-frequency transformers that could adequately work in the isolation stage of a SST, the efficiency of this device, the various modelling approaches and simulation tools used to analyze the performance of a SST (working a component of a microgrid, a distribution system or just in a standalone scenario), and the potential applications that this device is offering as a component of a power grid, a smart house, or a traction system.

This study presents the basic features of a Monte Carlo approach for reliability evaluation of distribution systems without embedded generation using parallel computation. The test system is represented by means of a three‐phase model that includes protective devices and is simulated during one year. The procedure has been implemented in an open environment in which OpenDSS is driven from MATLAB. The document includes a detailed description of the procedure, and some results derived from the simulation of an overhead distribution test system.

Un modelo de línea aérea de transmisión adecuado para el cálculo de sobretensiones originadas por el rayo debe incluir varias partes de la línea: conductores de fase y cables de guarda, torres, puestas a tierra, cadenas de aisladores y distancias en el aire. Un componente adicional, el pararrayos, puede ser necesario si el estudio tiene como objetivo evaluar el comportamiento frente al rayo de una línea de transmisión protegida mediante pararrayos. Este último aspecto es importante ya que el modelo a utilizar puede variar según se hayan instalado o no pararrayos para proteger la línea. El rayo es un fenómeno físico de naturaleza aleatoria. El cálculo de la tasa de contorneos (flameos) causados por descargas atmosféricas ha de realizarse teniendo en cuenta este aspecto, así como el comportamiento aleatorio que pueden tener algunos componentes de la línea aérea; por el ejemplo, las cadenas de aisladores. El objetivo de este artículo es doble: por un lado, se analizan las directrices propuestas hasta la fecha para representar líneas aéreas de transmisión en el estudio de sobretensiones atmosféricas y, por otro, se propone una metodología para seleccionar el modelo más adecuado de línea aérea de transmisión cuando se utilice una herramienta de simulación en el dominio del tiempo; por ejemplo, un programa tipo EMTP. Esta metodología es aplicada a un caso concreto de línea aérea de transmisión.

This paper presents an overview on available tools for the simulation of electromagnetic transients in power systems. Simulation tools range from specialized computer programs operating in real-time or non-real-time modes, to customized general purpose modeling environments. The various categories of tools are presented with highlights on applicability ranges and available modeling capabilities.

: This paper presents a time-domain model of a MV/LV bidirectional solid state transformer (SST). A multilevel converter configuration of the SST MV side is obtained by cascading a single-phase cell made of the series connection of an H bridge and a dual active bridge (dc-dc converter); the aim is to configure a realistic SST design suitable for MV levels. A three-phase four-wire converter has been used for the LV side, allowing the connection of both load/generation. The SST model, including the corresponding controllers, has been built and encapsulated as a custom-made model in the ATP version of the EMTP for application in distribution system studies. Several case studies have been carried out in order to evaluate the behavior of the proposed SST design under different operating conditions and check its impact on power quality.