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Author: n.sene
Type: Publication
Date: 2015-04-01

Transient recovery voltages in vacuum circuit breakers generated by the early-interruption of the inrush current of large motors

Description:
The switching of medium voltage electrical motors is typically realized by means of vacuum circuit breakers (VCBs) essentially in view of their elevated number of switching cycles. As known, switching... see more of VCBs generates important transient recovery voltages (TRVs)
that need to be properly evaluated in both VCB sizing and in the power system insulation coordination. As large medium voltage electrical motors are installed into plants typically controlled by means of Supervisory Control And Data Acquisition (SCADA) systems,
maneuvers that involve the motor inrush followed by its sudden de-energization (due, in general, to the intervention of an automatic diagnostic function), resulting into important TRVs, are not unusual. The paper aims at investigating the TRVs due to this specific type of
VCB switching by means of a model implemented in the EMTP-RV simulation environment. By making reference to a real plant, the validation of the implemented models is obtained by comparing the simulation results with some experimental transients provided by the plant data fault recorder. The paper finally discusses the adequacy of different countermeasures by analyzing their effectiveness for the TRVs limitation.

Authors: A. Borghetti, F. Napolitano, C.A. Nucci, M. Paolone, M. Sultan, N. Tripaldi

CIGRE - International Symposium “Assessing and Improving Power System Security, Reliability and Performance in Light of Changing Energy Sources” Recife, Pernambuco, Brazil, April 3-6, 2011
Topic 3 – System technical performance
Subtopic 3.5 – Switching and lightning transient on power systems. Impact on performance and measurements

Tag(s): Transient recovery voltages, vacuum circuit breakers, motor inrush currents, EMTP simulations

Author: n.sene
Type: Publication
Date: 2015-04-01

A PROCEDURE FOR THE AUTOMATIC SCHEDULING OF DISTRIBUTED ENERGY RESOURCES IN MEDIUM VOLTAGE NETWORKS

Description:
The paper presents the main characteristics of a centralized two-stage scheduler designed for the integration in the Distribution Management System (DMS) under development in the framework of an Itali... see morean “Smart Grid” Project. The paper first reviews the trends in the automation of power distribution networks, and then describes the two-stage scheduler and its application to typical Italian urban and rural distribution feeders.

Authors: Alberto BORGHETTI, Mauro BOSETTI, Carlo Alberto NUCCI, Mario PAOLONE, Stefano MASSUCCO, Federico SILVESTRO and Sandra SCALARI

C I R E D - 20th International Conference on Electricity Distribution Prague, 8-11 June 2009

Tag(s): Distribution Management System, Smart Grid, automation

Author: admin2012
Type: Document
Downloaded: 181 times
Date: 2014-06-02

Co-simulation Platform for the Analysis of Communication-based

Description:
The paper presents an ICT and power co-simulation platform for the analysis of the volt/var control and relevant optimization in medium voltage distribution feeders, achieved by means of a system of d... see moreistributed controllers coordinated via a shared band-limited digital communication network. The platform has been built by realizing the interface between two specific simulation environments: the Electromagnetic Transient Program EMTP-RV and the communication network simulator Opnet Modeller. The preliminary results provide basic indications on the expected performances of the considered communication-based strategies for different traffic congestion levels and load/generation dynamic variations.

Tag(s): Co-simulation, Networked Control Systems, Power distribution feeders, Volt/var optimization