The upgrading of transmission lines has shown to be an attractive alternative regarding the increasing demand of power and the difficulties for constructing new lines. In this paper, the study performed for upgrading an essential transmission line located in an industrial area at the SE region of Brazil will be presented. As the region where the line is located presents a high isokeraunic level, a set of TLAs (transmission line arresters) have been also installed in the referred line. The installation of TLAs has the aim of coping with both lightning and switching surges within the upgraded line. As in a first stage not all the towers will have TLAs, a study for choosing the most appropriate towers will also be presented.

The controlled switching of circuit breakers has shown to have a highly satisfactory performance for the reduction of electric transients in the electrical grid while maneuvering circuit breakers. A controlled switching device was developed for the utilization in the energization and de-energization of unloaded transmission lines as well as in the disconnection and subsequent energization of unloaded power transformers. The device was developed using a DSP (Digital Signals Processing) system which resulted from an R&D project between the University of Sao Paulo and the Electric Power Utility Company ECTE (Empresa Catarinense de Transmissao de Energia S.A.) that belongs to the TBE (Transmissoras Brasileiras de Energia) group.

This article describes the development of an unmanned monitoring system for the detection of hot spots inside a power substation. It uses an infrared camera connected to a robot which moves along the substation via a steel cable inside the substation. The robot is remotely controlled by a wireless system, operating at a frequency of 2.45 GHz (WiFi). The camera is dynamically directed to different substation components through a pan-tilt system. The whole structure is controlled by a microcomputer software located in a control room, around 200 m away from the robot. Aside of controlling the robot pan-tilt movements, the software also performs the data acquisition and analysis of thermographic images, thus detecting the referred hot spots.

The purpose of this article is to present the characteristics and results obtained from a data model development and implementation for georeferenced storage of equipments from substations and subtransmission lines, including their overhead and underground branches. This database will enable preventive, corrective, and emergency maintenance management of equipments, addressing operational and engineering departments needs. In addition, it allows technical application integration, such as power flow and short-circuit calculations, and contingency analysis. In this project, applications were also developed to make inspections/maintenance schedules available on hand-held computers. Created to fit every type of device, these schedules have to be filled and then transferred to the enterprise system. The system implemented, the pilot-project data survey methodology, the data modeling details, and some difficulties founded during this process are topics covered by this article too.

This work presents a project aimed at the videomonitoring of substation equipments, which resulted in a prototype installed in CTEEP's Bom Jardim substation. Although the system enables monitoring any one of the substation's devices, we decided to use it, in a first moment, to monitor the operation of disconnecting switches in this project, as they exhibit a high failure rate during the switching process. In the case of unassisted substations, CTEEP adopts communication by radio, with a data transmission capacity that is usually very low. This rate imposes limitations to the system in two distinct aspects: (1) the need of an image format with good compression rate, considering that image size is proportional to its quality (and good quality is a must); and (2) reduction in the number of images sent to the operator, limited to the ones that can identify the electric events occurred in the substation.

The electric engineering development has provided a more intense use of today's equipment with greater efficiency. But, often, such equipment cause distortions in the network's voltage and current waveforms and also it is sensitive to fluctuations of the network itself. Active filters constitute a feasible technological option for the mitigation of distortions and fluctuations, so as to improve the quality of energy and the development of mitigating technologies for harmonic distortions, through series and shunt voltage sources created by power electronics devices (DVR-dynamic voltage restorer). This project has been developed a mini-DVR prototype to: firstly, recompose the voltage transients present and operate as a voltage active filter, and secondly, act also compensating part of the reactive load, in this way, improving the voltage control. This device is in its final test phase at the EPUSP laboratory with the transient re-composition function (sag/swell and voltage harmonics).