Octavian Mihai Ghita

Evaluation method for harmonic distortion and power losses of photovoltaic systems using LabVIEW software

The use of photovoltaic power generation systems is increasing all around the world. However, photovoltaic systems use inverters and other electronics to convert and control DC power from panels to AC power. This may lead to increased power losses, decreased efficiency and power factor, overheating due to higher parasitic currents, and possible damages of the devices designed to work with smoother waveforms. In this paper, we used LabVIEW software to assess harmonic impact of such systems according to their specifications. Evaluation and calculation techniques were applied in order to accurately determine the level of distortion and other related power quality parameters.

Health monitoring solution using dedicated ZigBee sensor network

Health monitoring systems using wireless networks has become a constant concern in various fields, not only of medical plan but also in other domains in which bio-signal data collection from field teams, such as: firefighters, rescue service or emergency medical services, is important, especially in areas lacking communications. Mobile wearable sensors allow now more flexibility in collecting and transmitting these data. This paper presents a health monitoring system designed to work using a ZigBee network, suitable to be used in various fields of applications.

Design of a current sensor based on optical fibers

This paper present the design of a current sensor based on Faraday Effect using optical fibers devices and a polarizing beam splitter (PBS). Two different schematics are to be taken into account, for high currents and for smaller ones. A single polarized laser signal is sent to the PBS prism and two angular components are separated. From here, these optical signals are processed using some interfaces, a NI-DAQ acquisition board and a LabVIEW interface. After calculations, the unknown current is obtained function of the reflexion angle between the two light components.

Optimal model for efficiency of reegineering the Independent Power Grids

The reengineering of power grid networks is a necessary step that allow us to pass to the next generation of Distributed Power Networks. The frequent use of alternative green energies demand for better equipped networks including elements of smart grids, newer sensors, data transmission capabilities and extensive use of optical fiber. All these efforts implies higher costs, flexibility and scalability to be achieved. This paper present a mathematical model to analyze the efficiency of reengineering taking into account not only the costs, but also associated services and human resources involved.

Use of pedagogical agents to build multiple choice equations for an electric workshop based on LabVIEW

e-Learning, with its various aspects, represents a major trend in education. This paper presents a solution to extend the traditional multiple choice tests to effectively graphic design of calculus equations for an electric workshop. Equation built procedure was augmented using animated pedagogical agents to increase the effectiveness of learning and practical skills and improve the attractive aspect of the process. The implemented algorithms and software were tested on two groups of bachelor degree students from Electrical Engineering Faculty, proving useful results and ways to develop further works.

Risk Analysis and Optimal Model for Efficiency of Reengineering the Independent Power Grids

The reengineering of power grid networks is a necessary step that allows us to pass to the next generation of Distributed Power Networks. The frequent use of alternative green energies demand for better equipped networks including elements of smart grids, newer sensors, data transmission capabilities and extensive use of optical fiber . All these efforts imply higher costs, flexibility and scalability to be achieved. This paper present a mathematical model to analyze the efficiency of reengineering taking into account not only the costs, but also associated services and human resources involved. Also, involved risks are analyzed and methods for reducing these risks are presented.

Safety measures in testing aircraft wheeled parts

Quality and integrity of equipment used in aircraft manufacturing determine safety in the aerospace field. An important part of manufacturing process is to ensure good quality testing platforms, able to give full image information about the tested parts. This article is based on testing aircraft wheeled parts, parts subject to wear and stress. In order to achieve this test, a gear testing mechanical stand (cogwheels) was built. Different tests were performed, including sequence of long time use, heavy torque and low quality oil. The results were both positive and negative and show the importance of continuous monitoring measures of different parameters in order to be able to preserve safety along manufacturing process.

Client-server measurement system using LabVIEW for educational use

The today concern in educational software is to allow students maximum flexibility and autonomy in their laboratory work, combined with higher accuracy of measurements. This paper present a client-server system used as a virtual instrument for laboratory, built with LabVIEW stand-alone subVIs, designed for several different laboratories in the Electrical Measurements Department. Such systems are intended to work both in local or remote network configurations, being a vital component in Distance Learning.

Computer added monitoring of drilling rig systems

This paper describes a computer added system for monitoring and control for inland and offshore drilling rig applications. LabVIEW graphic oriented software provides a flexible and reliable support for SCADA. World wide drilling is developing for oil, gas or water resources and is demanding computer added monitoring and control for correct exploitation and safe use. This applied engineering software offers a complete monitoring for diesel generators of the local power station and electrical drives of the drilling rig.

Measurement data analyses using an expert system for oil-paper insulation evaluation

Diversification of tests and measurements for inspecting the state of the transformer unit insulation in operation, in order to establish the maintenance optimal strategy for increasing the safety in operation of this equipment, requires new diagnosis methods and insulation condition assessment like the recovery voltage method (RVM) and the polarization and depolarization current (PDC) measurement. Complexity of the transformer insulation structure and degradation mechanisms require special knowledge and experience. In this paper, an expert system (ES) is developed to bring insulation condition assessment procedure accessible to maintenance engineers.