Howlader A.M.,University of Ryukyus |
Urasaki N.,University of Ryukyus |
Yona A.,University of Ryukyus |
Senjyu T.,University of Ryukyus |
Saber A.Y.,Operation Technology Inc.
Renewable and Sustainable Energy Reviews | Year: 2013
Wind energy is inexhaustible renewable. Unlike conventional fossil fuels, wind energy is clean, abundant energy that will be available for future generations. However, wind speed is a highly stochastic component which can deviate very quickly. Output power of the wind energy conversion system (WECS) is proportional to the cube of wind speed, which causes the output power fluctuation of the wind turbine. The power fluctuation causes frequency fluctuation and voltage flicker inside the power grid. In order to reduce the power fluctuation, various approaches have been proposed in the last decades. This article deals with the review of several power smoothing strategies for the WECS. Power smoothing methods of the WECS are primarily separated into two categories such as energy storage based power smoothing method and without energy storage based power smoothing method. The main objectives of this paper are to introduce operating principles for different power smoothing methods. The energy storage based power smoothing method is effective but installation and maintenance costs of a storage device are very high. According to the literatures review, without energy storage based power smoothing method can reduce the cost of the WECS extensively. Various methods have been proposed to generate a smooth output power of the WECS without energy storage devices. Simulation results are compared among the available methods. From the review of simulation results, the kinetic energy of the inertia control method is the highly efficient power smoothing approach. © 2013 Elsevier Ltd. Source
Saber A.Y.,Operation Technology Inc.
International Journal of Electrical Power and Energy Systems | Year: 2012
This paper presents a novel modified particle swarm optimization (MPSO), which includes advantages of bacterial foraging (BF) and PSO for constrained dynamic economic dispatch (ED) problem. The proposed modified PSO consists of problem dependent four promising values in velocity vector to incorporate repellent advantage of bacterial foraging in PSO for the complex dynamic ED problem. It reliably and accurately tracks a continuously changing solution of the complex cost functions. As there is no differentiation operation in this method, all cost functions can easily be handled. The modified PSO has better balance between local and global search abilities and it can avoid local minima quickly. Finally, a benchmark data set and existing methods are used to show the effectiveness of the proposed method. © 2011 Elsevier Ltd. All rights reserved. Source
Mitolo M.,Operation Technology Inc.
IEEE Transactions on Industry Applications | Year: 2014
Outdoor lighting installations are publicly accessible electrical pieces of equipment. Upon faults-to-ground, the appearance of dangerous potentials on the metal parts of such equipment exposes persons to shock hazards. This unsafe situation poses serious problems to utilities, or municipalities, or whoever operates the lighting installations. This paper, through the analysis of the fault loops, seeks to clarify the reasons of the manifestation of stray voltages on public-exposed non-current-carrying metal parts, in light of different earthing systems as defined in IEC standards. © 2013 IEEE. Source
Operation Technology Inc. | Date: 2014-08-15
Systems and methods are provided for simulating fraction power and control in transportation systems under design conditions and/or utilizing real-time data.
Operation Technology Inc. | Date: 2013-10-03
Generator dynamic model parameter estimation and tuning using online data and subspace state space models are disclosed. According to one embodiment, a system comprises a sensor, a data acquisition network in communication with the sensor; a user console and an identification and tuning engine in communication with the data acquisition network, the user console, and a database. The database comprises one or more generator models, and the identification and tuning engine identifies and tunes parameters associated with a selected generator model.