Maria Emília de Lima Tostes

Prototype CNC machine design

The Computer Numeric Control (CNC) is a technology which aims to generate, parse and execute sequential actions that describes the behavior of the end effector. This article reports the development small sized prototype CNC machine, based on a modular system with the capability of communication through USB. It is also reported the development of the basic electronic devices to run a CNC machine and proposes, as well, a software developed in LabVIEW to establish the communication between the machine and the computer. The main objective of this work is the development of a machine which allows future researches on the process performance, on educational purposes, the demonstration the parts involved on the CNC machine.

An automatic methodology for obtaining optimum shape factors for the radial point interpolation method

In this letter, a methodology is proposed for automatically (and locally) obtaining the shape factor c for the Gaussian basis functions, for each support domain, in order to increase numerical precision and mainly to avoid matrix inversion impossibilities. The concept of calibration function is introduced, which is used for obtaining c. The methodology developed was applied for a 2-D numerical experiment, which results are compared to analytical solution. This comparison revels that the results associated to the developed methodology are very close to the analytical solution for the entire bandwidth of the excitation pulse. The proposed methodology is called in this work Local Shape Factor Calibration Method (LSFCM).

Software Based on LabView for Monitoring and Analysis Some Power Quality Parameters

This article presents a software developed for analysis of phenomena related to the Power Quality (PQ) in industrial systems, as variation of voltage, harmonic distortion and imbalance voltage, where the results are conveniently visualized in an user-friendly interface. This software intends to replace, in most situations, measurements made by traditional meters of PQ (equipment of high cost and rare used by the industries), thus reducing the costs related to these processes. The data base of this software allows raising descriptions of actions of preventive maintenance for the industry, increasing with this its level of competitiveness in the market.

Optimal capacitor banks placement in distribution grids using NSGA II and Harmonic Resonance Chart

This paper proposes a procedure to obtain optimal capacitor banks placement in distribution grids that incorporates a resonance analysis to the resulting Pareto Front optimal solutions, to guarantee that the adopted solution does not cause dangerous voltage harmonic resonance for the electric system. A multiobjective optimization procedure based on the Non-Dominated Sorting Genetic Algorithm II (NSGA-II) technique is used to solve the problem of optimal placement and sizing of capacitor banks, considering voltage magnitude and total harmonic distortion constraints, producing a Pareto Front of optimal solutions. The resonance analysis is accomplished by using the harmonic resonance chart, as proposed in [1] to identify if the Pareto or other viable solutions can cause dangerous harmonic resonance. To test and validate the proposed methodology, a 34-bus radial distribution network was used considering typical non-linear loads as harmonic current sources. The obtained results were very effective which indicate the proposed procedure is very promising in obtaining solutions for this type of problem.

Software Project Development for Industrial Motor Systems Simulation

This paper shows the development of a software to be used in industrial motor simulation, making possible to the electrical energy efficiency be analysed in the four most important industrial systems. Through this program the user will be able to simulate the behavior of centrifugal pump, compressor, belt conveyor and industrial fan. The user can visualize the real industrial motors behavior and can predict the electrical energetic efficiency of them. The software can be used as a tool for energy diagnosis and also to assist the decisions in industrial motor systems projects. The software was developed in LabVIEW 7.0 and the data measured in simulations were stored in a database developed in MySQL. The computational validation was made by comparison between real machines parameters and simulation parameters. The industrial motors energy monitoring is very important currently because it is an innovative area, strategic and of great exploitation for the industrial sector as well as for the educational sector. The software have a significant importance for industrial sector and for academic students, which can use the software to study and to make an analysis on the behavior of industrial motor systems, even without access real industrial systems

Voltage THD Analysis Using Knowledge Discovery in Databases With a Decision Tree Classifier

Industrial production has evolved significantly over the last decade. For this reason, it is necessary to obtain mathematical and computational tools that enable power systems engineers to make decisions that reduce harmonic distortions in accordance with international standards. This paper presents a total harmonic distortion (THD) assessment based on full knowledge discovery in databases (KDD) using power quality (PQ) standards and computational intelligence tools. The materials and methods of THD assessment consist of load and layout analysis; choice and installation of PQ analyzers; and the application of the full KDD process, including collection, selection, cleaning, integration, transformation and reduction, mining, interpretation, and evaluation of the data. This research methodology was used in an electrical and electronic industry; the results obtained have characteristics that can be used as a reference for other types of analyses. The results indicate that these methods can be applied to several industrial applications such as: 1) the description of the complete KDD process for THD assessment of the point of common coupling; 2) simultaneous collection using five PQ analyzers at several points in the electrical network; and (3) the use of a decision tree classifier.

Comparing NSGA-II and SPEA2 metaheuristics in solving the problem of optimal capacitor banks placement and sizing in distribution grids considering harmonic distortion restrictions

This paper focus on the optimal capacitor banks placement and sizing problem in radial distribution systems considering the presence of non-linear loads and their effects on the voltage harmonic distortion. A comparison between two multiobjective optimization methods used to solve this problem is accomplished, namely, NSGA II and SPEA 2. The performed analysis has shown that both algorithms are appropriate to solve the problem, particularly by the multiple solutions that form the Pareto front from which can be extracted convenient solutions. It is also emphasized the differences between the two methods and their consequences in determining the results. The relevance of this work is founded on new challenges that are related to resonance problems involved in the placement of capacitor banks in distribution systems.

Harmonic Impact analysis coming from the manufacturing processes of a Eletroeletrônica Industry Using KDD and Decision Trees

This paper approaches the analysis of the current distortion impact due the harmonic frequencies present at the power grid of an industry facility at Manaus during the manufacturing process of informatics devices. The reason for such frequencies to appear are the presence of non linear loads from personal computers, notebooks and tablets. The data were collected in a measurement campaign during a week, using quality energy analyzers at different production process supplied by 13,8kV and with a nominal load of 800kVA. The main objective of this paper is to present an analysis based on computational intelligence using decision tree to determine and quantify the harmonic distortions commonly present at manufacturing process of informatics industries using simultaneous measurements of voltage and current to determine which process has the biggest impact in the total harmonic distortion at the common coupling point between the factory and the energy dealers.