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The scheme and the parameters of the generator pulse currents, simulating actual flowing currents on wind turbine blades are presented. The form and duration of these pulses are considerably different from the standard. The results of experiments on the action of current pulses to the material of the blades are shown. Measures to increase the lightning-resistant of wind generators are suggested.
The range of new approaches based on interconnected circuit theorems was considered to implementation, synthesis, and diagnostics of devices providing the traffic safety. The methodology for new devices implementation is based on the mathematical tools: theory of operators, Laplace transformation, modern methods for synthesis of the named classes of circuits and systems, possibility of excluding inductive...
The standard lightning waveforms used for the testing of aircraft are based on downward lightning. However, there is evidence suggesting that lightning to aircraft is different from negative downward lightning. Also, carbon fiber composite materials are being used extensively in wind turbines and aircraft which comprise small, sensitive electronics as part of avionics and control systems. In this...
The ampacity of underground power cable lines is limited by the maximal allowable temperature of the conductor. Normally the IEC 60287 standard is used for steady state ampacity calculation. The standard employs the concept of thermal equivalent circuit. An alternative to the standard is the finite element (FEA) simulation of electromagnetic and thermal field around cables. This paper presents a systematic...
Actually, it is proved that electromagnetic fields created by the electrical transmission network and equipment, have on our health a significant impact. The level of exposure to EMF can be effectively reduced by the inclusion of preventive measures at the design stage with the use of software packages designed to calculate the level of electromagnetic fields. The advantage of using software such...
Components of the electric power system influence on its surrounding. The created electromagnetic radiation has an impact on the human body as well as on the electric equipment, such as instrument transformers and power line communication system. A methodology for EMF estimation of neighboring transmission lines was developed. Such parameters as mutual disposition of lines and their wires, the amplitude...
Genetic algorithm (GA) is widely used in the electric energy systems. GA can serve to find solution of optimization problem with the reasonable time and resources. GA is defined with parameters and selection criteria. The dispatcher receives the results of the optimization with using GA for the subsequent analysis and using in electric energy system. In recent years the mathematicians achieved the...
In this paper, we report the results of wind turbine grounding system impedance measurements performed at the Mont-Crosin wind park in Switzerland. Experiments were carried out twice: (1) when only the construction of the wind turbine foundation had been completed, and (2) once the installation of the rest of the wind turbine was finished: tower, nacelle and blades. The transient grounding impedance...
Ice covering represents a huge danger for transmission lines (TL) and ground wires (GW). It may lead to short circuits and even wires' breakage. To prevent it, ice-melting procedure is required. The currents of operating TL influence on the de-icing process. A mathematical model of the ice-melting circuit was developed which makes possible the estimation of this influence. Parameters of the model...
Many electrical problems involve the simultaneous solution of equations from different physical domains, i.e. require multiphysics solution. Multiphysics problems are typical for many electrical applications. Most of difficulties arising here are subject of study and classification. For example, for multi-physics analysis is typical to combine several physical models with different level of details...
The TL (transmission lines) and the GW (ground wires) ice covering represents a danger to the power systems' operation. When the ice-melting procedure using rectifiers is conducted, accidents due to the induced EMF in the GW from the TL currents are possible. In this paper the induced EMF values are calculated for different TL operation modes, different positional TL relationship and different ice-melting...
In this paper, we present the calculation of the effective height of the Gaisberg tower using several models in which the Gaisberg Mountain is represented by either simplified geometrical shapes (hemisphere and hemiellipsoid), or by using the actual 3D topography. The procedure to estimate the effective height based on the comparison of the electric field at the top of the tower located on flat and...
A new method to estimate the number of upward flashes from tall structures is presented. The method is based on the analysis of the data provided by lightning location systems (LLS) and thus could be applied for any tall structure located in the region covered by a LLS. About 80 tall objects in Europe with heights ranging from 100 m to 300 m were selected for the analysis. LLS data for a period of...
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