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Disturbances in low-voltage control circuits in substations and power plants occur due to lightning or switching surges. Adequate protection of electronic devices in low-voltage control circuits requires the capacity to predict surge phenomena and to evaluate the effectiveness of protection methodologies. In this paper, we present and validate a technique to represent twisted-wire pairs, which are commonly used in control circuits, for surge simulations using the Finite-difference time-domain method combined with the Agrawal et al. model. [ABSTRACT FROM PUBLISHER]

Here, we present preliminary results obtained from a station that monitors the Schumann resonance between ~0 Hz and 50 Hz. The station is currently under development in Mexico (latitude 19? 48? 19? N, longitude 101? 41? 39? W). This station is the first of its kind in the region that includes Mexico, the Caribbean and Central America. The station has two inductive antennas, one for each horizontal magnetic field component. We measured Schumann Resonance harmonics at 7.74, 14.11 and 20.22 Hz. We present the frequency and amplitude behavior of the first three Schumann Resonance harmonics between 00:00 and 08:00 LT along several days during April, 2012. [ABSTRACT FROM AUTHOR]

This letter demonstrates the use of modal logic for knowledge representation for condition monitoring of gas turbine start-up sequences. The potentially large amounts of data and the complex real-time processes behind on-line fault detection indicate the need for software entities that can reason and react to changing environmental conditions. These are known as intelligent software agents. As a consequence, data interpretation is achieved by converting the data into appropriate information and combining individual agents' knowledge, resulting in an automatic fault diagnosis. [ABSTRACT FROM PUBLISHER]

We suggest the contactless power transmission system "Cordless Power Station (CLPS)" that will radiate little noise by making the coil geometry noise-reducible. The system makes use of electromagnetic induction among the coils. So far we have studied the structures of CLPS consisting of some spiral coils, and found out that CLPS could be small-sized and thin. The enough amount of power could be transmitted. In this paper we suggest the structure consisting of meander coils (meander type), which has allowances in coil displacement and is easy to be set up. We studied the power-transmitting characteristics with various magnetic materials and coil misalignment. We also discussed the efficiency improvements in the spiral type. Later we make a comparison in characteristics between spiral type and meander type. [ABSTRACT FROM PUBLISHER]