Eduardo Lorenzetti Pellini

Automated fault location system for primary distribution networks

This paper presents the development, simulation results, and field tests of an automated fault location system for primary distribution networks. This fault location system is able to identify the most probable fault locations in a fast and accurate way. It is based on measurements provided by intelligent electronic devices (IEDs) with built-in oscillography function, installed only at the substation level, and on a database that stores information about the network topology and its electrical parameters. Simulations evaluate the accuracy of the proposed system and the experimental results come from a prototype installation.

Fault-Location System for Multiterminal Transmission Lines

This research presents the development and implementation in a computational routine of algorithms for fault location in multiterminal transmission lines. These algorithms are part of a fault-location system, which is capable of correctly identifying the fault point based on voltage and current phasor quantities, calculated by using measurements of voltage and current signals from intelligent electronic devices, located on the transmission-line terminals. The algorithms have access to the electrical parameters of the transmission lines and to information about the transformers loading and their connection type. This paper also presents the development of phase component models for the power system elements used by the fault-location algorithms.

IEC61850–Based Systems—Functional Testing and Interoperability Issues

This paper presents a proposal for functional testing of protection and automation systems based on the IEC61850 standard. The proposed methodology is based on the development of tests scenarios which properly represent the actual systems and their operative conditions. It includes the selection of hardware and software that are used to simulate the operational events and acquire data for further analysis. This methodology was developed to evaluate the protection and automation systems of large-sized substations mainly regarding the interoperability between intelligent electronic devices of different manufacturers. This paper explains in detail the proposed methodology and an actual case study.

Sistema para localização de faltas em linhas de transmissão com subestações conectadas em derivação

This paper presents the development and implementation of algorithms for fault location in multi-terminal transmission lines. The proposed fault location system is capable of correctly identifying the fault point based on voltage and current phase components, calculated using measurements of voltage and current signals from intelligent electronic devices, located on the transmission line terminals. The algorithms, which are parte of the system, have access to the electrical parameters of the transmission lines and to information about the transformers loading and their connection type. This work also presents the development of phase component models for the power system elements used by the fault location algorithms.

A Python based power electronics E-learning tool

Simulation became an integral part of power electronics and electrical drives learning process. This paper presents a collection of software programs that can be useful in the teaching process of power electronics and electrical drives. This tool is developed with Python language and libraries, which can be freely distributed. Without going through complicated mathematics and software manuals, students can obtain steady state waveforms from power electronics circuits, their mean and RMS values, as well as spectra. Electrical machine principles are also shown, using animation tools.

H-infinity current control of the LC coupled voltage source inverter

The hybrid active harmonic filters use a series capacitor in order to reduce the voltage rating of the inverter compared to regular inductive-coupled active filters. Different control strategies are applied on this topology in the literature. The main contribution of this paper is to apply a H-infinity controller in order to achieve current tracking in voltage source inverters connected to the grid through a series LC coupling impedance. The primary goal of this control system is to track a harmonic reference current, in order to address power quality issues on the grid. An overview on the controller synthesis process is given. The discretization process is shown together with the controller robustness investigation using mu-analysis. Finally, the simulations are validated through experimental measurements using the synthesized controller.

Fuzzy logic applied to registration of alarms and events in substations with IEC 61850

When fault occur in electric power systems, protection and automation schemes take all necessary actions to properly isolate the problem, assuming a safe or emergency operating state. On these occasions, human operators should review all messages, events and alarms from SCADA to understand the underlying situation. Only after this analysis, based on previous experience and knowledge, the operators may order the system restoration to a normal operating state. The data to be understood are usually conflicting, confusing and numerous, since they were sequentially triggered by many devices, resulting in an avalanche of information. Due to these characteristics a full human-based analysis is difficult, slow and prone to failure. This paper addresses a Fuzzy logic based diagnosis system, which can quickly interpret the avalanche of data resulting from an undergoing fault situation, to properly access, assist and ease the human-based operation of the power system. The system used a novel scheme, with fully compliant IEC 61850 communication scheme, solely based on GOOSE and MMS messages, to acquire data from all substation equipment, as long as a modern programmable controller, to execute all artificial intelligence routines needed.

Real time simulator for hydro-generator excitation systems

This paper presents a real time digital simulator developed for testing hydro-generator static excitation systems in a hardware-in-the-loop approach. Thus, the complete excitation panel, including transducers, digital control loops, state sequencer and the thyristor pulse generation hardware can be tested. Any kind of synchronous machine, hydraulic turbine and electrical network can be represented. A large set of events can be simulated, from the machine startup process to triphase faults on the transmission lines. The simulator can be operated in two different modes. The online mode follows the hardware-in-the-loop scheme, where real time performance is required. The offline mode is a computer-only simulation system, which includes an emulation of the programmable logic controller software in addition to the hydro-generator static excitation system.