Arnulfo Barroso de Vasconcellos

Transformer Controlled Switching to Eliminate Inrush Current - Part I: Theory and Laboratory Validation

The technology of power transformer modeling is studied in this paper and a switching strategy is proposed for controlling the phenomena associated with transformer inrush currents. A comprehensive time-domain program is developed to deal with these transients and a solution for obtaining the required residual fluxes is considered. The approach is computationally implemented and both the theoretical and the experimental investigations are carried out to highlight the method of application and its validation. The results emphasize the possibility of building devices that eliminate the well-known transformer inrush currents and their side effects

Saturated core reactor static compensator: computational versus experimental performance analysis

This paper presents theoretical considerations, as well as results related to computational and experimental implementation of a saturated core reactor static compensator (SCRSC). This equipment, together with its parallel and series capacitors, congregates the ability of dynamically absorbing or supplying reactive power as required by different applications. The main attraction related to this product, besides low cost and simplicity, is that its control is of intrinsic type. A time domain model implemented into a time domain computational simulator is used for theoretical investigations. The model validation is performed by means of a laboratory arrangement consisting of simplified electrical system and a saturated reactor compensator prototype. Typical theoretical and experimental system/compensator results are given to illustrate the overall behavior under voltage variations.

Energy quality in an operation center of data processings

The manipulation of the information through the use of computer science is the main responsible for the technological advance providing improvement in the quality of life. This provided to an increasing use of no linear loads in all sectors. Mainly, in the centers of network operation. The knowledge of the reply to these loads is important in the brainstorming that aims at the improvement of the energy quality. This paper presents measurements in common no linear loads in installations of a center of network operation. It analyses if the individual and total distortions of voltage are in accordance with Resolution 345/2008 of ANEEL.

Analysis of power quality in a system of relay TV

The processing of information through the use of digital equipment and computer technology is largely responsible for the technological advancement, which has reflected in the improvement of the quality of life of the population. As a consequence, there was an increasing use of nonlinear loads in all sectors, particularly in systems for broadcast TV. The knowledge of the response of these loads is important in the search for solutions aimed at improving the quality of electric power. This paper presents measurements on a bus that feeds nonlinear loads in common facilities of a TV relay station and analyze the harmonic distortion of current and whether the individual harmonic distortion and total pressure are in accordance with Resolution 345/2008 by National Agency of Electrical Energy (ANEEL).

Energy efficiency and harmonic distortion in automation of air conditioning

The objective of this paper is to analyze the replacement of conventional air conditioner for air conditioner driven by frequency converter in a Consumer Unit (CU) used for public service activities, which carries in addition to increased energy efficiency, positive impact on invoice for electric power of CU. However, when observing the effects of the use of the frequency converter on the electric energy quality in systems where they are employed, verified the appearance of unwanted harmonic distortion in the network. This paper analyzes the process of replacing the proposed system and verifies the impact on the reduction of energy consumption and electric power quality.

The influence of the non-linearity of electric loads on capacitive compensation

The analysis of the power factor and the level of harmonic distortion in an electric system in the presence of non-linear loads are of importance in terms of the legislation enforced by the National Agency of Electric Energy (ANEEL). In this context, this paper uses computer simulation to analyze the influence of the Total and Individual Harmonic Distortions of the Current and of the Voltage on power factor correction on a busbar that feeds linear and non-linear loads.

Applications of tuned passive harmonic filters in a busbar with non-linear loads

The analysis of power factor and the level of harmonic distortion in an electrical system in the presence of non-linear loads is of great importance with regard to power quality and enforcement of existing laws and standards established by national and international regulatory agencies. As a result, this study examines the power quality of a secondary busbar which are connected non-linear loads. In this context, through computer simulations, we observed the effectiveness of tuned passive filters in order to reduce the levels of harmonic distortion and adjust the power factor of the system under study.

A strategy for voltage regulation in Eolic systems

This paper presents a comparative performance analysis of a wind power generation unit with and without the inclusion of a reactive compensator known as saturated core reactor (SCR) to improve voltage variations resulting from the wind power. Besides demonstrating the solution efficiency and adequacy for voltage control, the results can also be used to validate the established computational model. Field results, derived from a real system with and without the compensator insertion are given to enhance the overall system/compensator/generators behavior.

Analysis of reactive power flow in the lighting system of a consumer unit

The main focus of this paper is to analyze the reactive flow LED front lamps to sodium vapor lamps. With the advances of technology, there is an increase in the use of electronic loads in all sectors, and in this context fits the LED lamp, which has been used in electrical efficiency projects. Both laboratory and field measurements using LED lamps, and meters indicate that a reactive power flow injected into the bus may influence the electrical system power factor, thereby influencing the measurement for billing purposes. This paper presents measurements in laboratory and field LED lamps and sodium vapor, and analyzes its influence on the charging system.

Behavioral and statistical analysis of total harmonic distortion input frequency converter of a triggering an industrial fan: A case study

In the context of power quality the harmonics problems are regulated by normative recommendation based on levels of individual and total distortions by ANEEL - Brazil (National Electric Energy Agency). This paper outlines and implements methodology for mathematical and statistical analysis of the behavior of the total harmonic distortion of voltage and current at the input of a frequency converter feeding an induction motor common, coupled to a mechanical centrifugal fan. The results show a trend of decreasing harmonic distortion with increasing frequency drive the load in question.