Eduardo Cesar Senger

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.

Broken conductors protection system using carrier communication

This paper presents a detection and signaling system designed to identify and locate high impedance faults caused by broken conductors on distribution primary feeders. Unlike conventional protection systems, which perform current sensing, the working principle of the proposed system consists on monitoring the voltage unbalance along a feeder. This allows the system to detect a fault occurrence even in cases when the conductor touches a high impedance earth surface (for instance asphalt). This system has an additional advantage of giving an indication of the location of a fault since it involves measurements at multiple points on a feeder. In order to detect the voltage unbalance produced by a broken conductor, a new sensor was developed which is sensitive to the electric field generated by primary feeders. A carrier communication channel is associated to each sensor allowing the high impedance fault occurrence information to reach the protection equipment located closer to or at the substation.

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.

Reducing Arc Flash Incident Energy Level in an Offshore Gas Production Unit Using Intelligent Electronic Devices—A Case Study

This paper evaluates the protection system of an offshore gas production unit and proposes utilization of devices dedicated to identify the arc flash incidents inside the panels. A quantitative analysis has been performed by comparing the incident energy levels of the original design with the levels provided by the new design. The new design includes numerical relays equipped with dual sensing of arc flash: optical detection of the light and high-speed overcurrent detection. The analysis indicates that a drastic reduction of incident energy can be achieved. The reduction is based on very fast detection and elimination of the arc, lowering the arcing time.

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.

Reliability of digital relays with self-checking methods

Abstract This paper addresses the reliability of protection system relays considering the self-checking resources. The operation of the relay is modelled by a Markov chain with the failure to operate and unnecessary operation states. The model applies to both conventional and digital relays. Data from the Brazilian transmission line protection systems were used for the determination of the conventional relay parameters. For the digital ones the total relay failure rate was estimated and the reliability indexes were calculated for different values of self-checking efficiencies and preventive maintenance intervals.

Maintenance Strategy for Electrical Equipment Based on Integrated Operations

This paper presents a methodology to define a maintenance strategy for electrical equipment, including electric motors. This methodology is based on reliability-centered maintenance, and aims to ensure that the maintenance strategy results in maximum availability and efficiency of equipment and systems. The methodology is also compatible with the philosophy of integrated operations recently developed by the Norwegian petroleum industry to optimize the production from their mature oil fields. The first step is focused on the determination of the equipment criticality value. The paper proposes a methodology based on the Mudge method. Reliability criteria are adopted according to the criticality value. The maintenance intervals are determined considering the reliability criterion and the failure rate of each part of a motor. After determining criticality, the maintenance strategy and tasks are analyzed and determined based on failure modes and failure rates. To support this analysis, a procedure based on failure mode and effect analysis theory is used.