Engineering, Technology & Applied Science Research

23-29

Authors: H. P. Nabi, P. Dadashi, A. Shoulaie

Vector control is one of the most popular multiphase induction machine drive methods due to its dynamic performance. Since all phase currents are needed in vector control drive, by increasing phase numbers, the number of required current sensors increases which is one of the disadvantages of vector control in multiphase machine drives. In this paper vector control of a symmetrical six-phase induction machine with a novel configuration is presented. The aforementioned configuration is designed in a simple way that only three current sensors will be needed. Analytical equations are extracted in this paper to show that some of current components which do not contribute in torque production will be eliminated due to the proposed scheme. Simulation and experimental results are provided to verify the benefits of the proposed configuration.

36-42

Authors: D. Pylarinos

Leakage current (LC) monitoring is a widely employed tool for monitoring the performance of high voltage insulators. LC waveform monitoring is required to acquire a view of the phenomena experienced since the type of LC waveform’s shape is correlated with different types of electrical activity. In case of field monitoring, specially designed measuring systems, capable of operating under field conditions, have to be installed. The Greek Public Power Corporation (PPC) has issued a large project for monitoring the performance of outdoor insulators. A commercially available LC measuring system, was purchased and installed by PPC. The system was able to monitor various outdoor insulators, record several statistical values and intermittently record a LC waveform. The provided software lacked some capabilities that were required for certain research areas and a custom made software had to be developed. In this paper, two stand-alone MATLAB based softwares, “Leakage Current Waveform File Converter” and “Leakage Current Waveform Viewer”, both equipped with a user friendly GUI, are presented. The first software was developed in order to automatically convert multiple files from the CSV format (as extracted from the measuring system) to the MAT format in order to allow data compactness and further processing. The latter software was developed in order to offer a tool for collective viewing, printing and extraction to JPEG format, of LC waveforms in groups of user-defined numbers. The latter function gives the opportunity for easy and fast creation of waveform archives.