By Hans De Keulenaer / Published on Fri, 2008-07-25 17:04
By Alex McEachern
A free Windows® program for teaching power quality concepts is presented. The program uses interactive graphs and controls. Concepts include fundamental and reactive power, sequence vectors, voltage dip effects on single-phase and threephase rectifier loads, flicker, harmonic concepts, harmonic power flow, harmonic sequencing, and distortion and source impedance. The program operates in English, Spanish, French, German, Italian, Portuguese, Romanian, Swedish, and Polish, with Japanese and Malaysian expected soon.
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By Hans De Keulenaer / Published on Fri, 2008-07-25 16:56
By P Lloret et al
In the last decades there have been great advances in electronic, information and communication technologies. Up to date, any of these advances have been implemented in electrical systems, but some difficulties have been encountered, particularly regarding to the integration of intelligent electronic devices from different manufactures into a centralized system. With the aim of solving the above mentioned problem, the standard IEC 61850 was developed to specify communication networks in substations.
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By Hans De Keulenaer / Published on Fri, 2008-07-25 12:09
By E Darie
This work analyses the operation of inverter-fed asynchronous motor drives accompanied by high-frequency interferences caused by parasitic currents of the common and differential modes. These emissions propagated by conduction and radiation may unfavorably affect the operation of nearby telecommunication and signal cables and various low-current devices. The study of these phenomena is based on theoretical considerations and numerical analysis.
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By Hans De Keulenaer / Published on Fri, 2008-06-27 10:24
By J Arbi et al
In this paper, the authors study a variable speed wind generation system based on Doubly Fed Induction Generator (DFIG) in case of large balanced voltage dip and analyzed a remedial solution that allows for the turbine to stay connected and helps grid recovery through reactive power injection, by supplying the grid with reactive power during faults. Simulation results show the effectiveness of the solution in different operating points of the four working regions of the power-speed turbine characteristic.
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By Hans De Keulenaer / Published on Wed, 2008-06-18 13:10
By G Blajszczak
The paper describes importance of the reactive power control basing on the failures and control problems in the Polish transmission networks in summer 2006. A detailed description of the operational difficulties is provided. Conclusions, repairs and prevention undertaking are also described.
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By Hans De Keulenaer / Published on Fri, 2008-06-13 16:03
By J Paska
Even, or may be particularly, in the time of disintegration, deregulation and competition in a power system, its reliability is one of the most important criteria which must be taken into consideration during planning and operation phases of its life. Historically, the power system reliability has been assessed using deterministic criteria, techniques and indices. Nowadays it is assessed using probabilistic criteria, techniques and indices as well as applying complex mathematical models and sophisticated computer tools for their realization.
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