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Theoretically, the shape of Neutral to earth voltage (NTEV) on the commercial building is normally imitating to the neutral current profile. However, in real cases condition, the shape of waveform is different due to the grounding system influenced by the frequency variation. The frequency variation on the grounding system typically can be allocated into two modes of frequency; lower and higher frequencies...
The paper presents an example of modeling high-voltage line with classical columns and pillars compacted with the same lines and testing out the model in the programming tool DIgSILENT with actual measured data for Single Line to Ground Fault with the use of ARs. The parameters of the classical and compacted 400 kV transmission line are entered into the model in the example of 400 kV line Tuzla 4...
Conductors with rectangular cross-section are key components of industrial busbar systems, where each phase can have several parallel conductors to carry high currents. The current density in each conductor, under sinusoidal conditions, is not uniform, due to skin and proximity effects. As there are no closed analytical formulae for conductors with rectangular cross-section, many numerical simulations...
For the crack intermittency detection in circuit board, a detection method based on time domain reflectometry is proposed. And a time domain signal feature is extracted, the time domain signal feature is highly sensitive to the defect. Firstly, in order to analyze the change trend of time domain signal under intermittent disconnection. The influence of conductor crack on the physical parameters is...
This paper deals with studying the behavior of a photovoltaic (PV) array in faulty conditions. In this context, the authors propose a new approach offering a good evaluation of the PV array performances under progressive faults. The approach implemented in Matlab/Simulink, is based on the analysis of anomalies shown in current-voltage (I-V) and power-voltage (P-V) characteristics, which are obtained...
Low voltage distribution feeders have many imperfections. Their theoretical models give results far from actual values because of ignoring many extraneous factors. Small PV plants have a major share among renewable energy based Distributed Generators. They are interconnected with grid at Low Voltage (LV) distribution level which may adversely affect the voltage profile and phase balancing. Proper...
This paper addressed surge propagation on a vertical line with a discontinuity. A formula of surge reflection coefficient expressed by specially-defined surge impedance was introduced, which is similar to that of a conventional transmission line. The formula for the discontinuity with a lumped resistance was also presented. With these formulas, surges on the line with the discontinuity can be evaluated...
Abstract Planar spiral windings have garnered a significant amount of attention recently due to the popularity of slim consumer electronics combined with their low-profile, high reproducibility, and simple manufacturing. Unfortunately they still suffer from high internal capacitance which limits their use at high frequencies. This work presents the novel inverse Track-Width-Ratio (TWR) planar structure,...
This paper describes the progress of work towards an Open Source software toolset suitable for developing Spice based multi-conductor cable models. The issues related to creating a transmission line model for implementation in Spice which include the frequency dependent properties of real cables are presented and the viability of spice cable models is demonstrated through application to a three conductor...
A system to emulate railway DC systems is presented in this paper. The emulator is designed to simulate the behavior of railway systems in terms of stray currents and touch voltages. Power electronics circuits are used as variable resistors to simulate the train motion. The emulator provides a test-bed to not only study and analyze the effects of stray currents and touch voltages, but to also evaluate...
In this paper we investigate multi-layer tubular conductor for multi-MHz Wireless Power Transfer (WPT) systems high-Q (quality factor) resonators. The conductor layers thickness and current sharing between them are optimized at 13.56 MHz, showing significant reduction in conductor AC resistance (RAC). Capacitive ballast is used as a practical method for current sharing between layers and operation...
The installation of HVAC underground cables became more common in recent years, a trend expected to continue in the future. Underground cables are more complex than overhead lines and the calculation of their resistance and reactance can be challenging and time consuming for frequencies that are not power frequency.
The paper deals with the calculation of Joule's losses on overhead transmission lines. The presented method allows taking into consideration the influence of a current asymmetry caused by various conductors layout and their inductive and capacitive couplings. The losses evaluation has been carried out with respect to the total transmitted energy, data given by year and day load diagrams were used...
This paper presents a new technique to characterize the electrical behavior of the arc furnace through the measurements of the electric power in stationary and transient imbalance of these systems. The non-stationary signals measured voltage and current in electric arc furnaces, behavior are characterized using a technique of analyzing the quality of the power in the time-frequency domain. To validate...
This paper deals with deep bar effect in squirrel cage rotors. Induction machines using this type of rotor are widespread. Some cages enhance the deep bar effect to improve the starting performances. In cited references, the analytical calculation of the equivalent circuit parameters has only been investigated for single-cage and double-cage rotors. In this paper, an analytical model is developed...
The research on feeder sequence impedance can enhance power quality, reduce the weight of power system and improve the electromagnetic compatibility. In this paper, the sequence impedance with the airplane skin as neutral is analyzed in the large-capacity variable frequency power system. The skin factor and proximity factor which affect resistance, as well as inductance in different frequencies are...
This paper describes an accurate digital distance relaying scheme integrated with artificial neural network block is developed using zero sequence component of a fault current and conventional ground impedance values, assuming that the conventional ground impedance always have some error impedance associated in it. The modified scheme is immune to the variation in fault location for under reach and...
An accurate digital distance relaying scheme integrated with artificial neural network impedance estimator is developed using the weighted sum of the negative-zero sequence components of fault current assuming the voltage and current are in phase at the fault location. The modified scheme is immune to the variation in fault location for under reach and overreach problem caused by sequence current...
The volume integral equation used in the method of moments based resistance and inductance extractors is reduced to a novel surface integral equation featuring a global surface impedance boundary condition as well as a product of volume and surface integral operators. The reduction is achieved by employing the equivalence principle representation of the electric field in the conductor cross-section...
For recent VLSI circuits, the clock frequency and integration density have continuously increased. Thus, accurate estimate of the per-unit-length resistance and inductance of interconnect has become important for maintaining the signal integrity [1]. In order to design for the transmission lines successfully, it is necessary that correctness of the selected formulas or numerical methods can take into...
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