With the wide spread of transmission lines and distribution networks, there is a higher exposure to magnetic fields generated by those lines, leading to more cases of human health impacts. The aim of this paper is to conduct a comparative analysis of magnetic field levels in the vicinity of a three-phase overhead line, which mounted on a steel lattice and a reinforced concrete columns. The analysis includes the influence of the change in phase position of all currents, both in low and medium voltage system of the considered mixed lines. Emphasis have been consented on investigate the influence on distribution of magnetic fields of the currents induced in the ferromagnetic and conductive parts of the columns. The mathematical calculations were conducted numerically by using "COMSOL"Multiphysics software package, which is based on application of the finite element method, on twodimensional mixed lines model. The obtained results indicate that the intensity of magnetic induction vector decreases in the area around the columns due to the induced currents in ferromagnetic conductive parts of columns. This phenomenon is more pronounced in steel lattice columns, while it is less pronounced in the reinforced concrete columns.

Increasing the effects of global pollution and the availability of renewable energy sources has push many countries to use reasonable energy sources such as wind and solar energy. This paper presents a case study of evaluating a hybrid renewable energy system by using a hybrid optimization of multiple energy resources (HOMER) software program based on the entered data available from the net for the considered location. The hybrid system consisting of a wind turbine, a photovoltaic system, a battery and a diesel generator. The simulation results are presented in a graphical curves n HOMER software. The obtained results indicate that by using the HOMER simulation program, the optimal design of the hybrid electrical power system for the considered location can be achieved which can help the designer to decide the types and number of the competent required for conducting the intending hybrid electrical power system which results in optimum output power in addition to reducing the overall operating costs.

The aim of this paper is to conduct a mutual comparison of switching energy losses in cascade gallium nitride (GaN) and silicon "super junction" MOSFET” transistor, in both cases designed for a maximum operating voltage of (650 V). For the analysis of switching characteristics of transistors used double pulse test method by using detailed SPICE simulation model. Data on transient on and off processes were generated using the “LTspice” simulation package in a wide range of drain currents with two different gate resistance values of the tested transistors. The total energy losses in the GaN have been simulated during one transistor at (on and off cycle). The obtained results indicate that the superior switching characteristics of GaN devices for a drain current of (30 A) is five to eight times less than the switching characteristics of silicon “MOSFET” transistor when compared to silicon components, especially during operation of transistors with high drain currents.

Transmit antennas are chosen in multi-input-multi-output (MIMO) systems. Effective in improving system capacity while lowering RF connection costs and simplifying the system. Complete method with greatest accuracy for joint transmits and receive antenna selection (JTRAS), capable of scanning all subsets of both transmitting and receiving antennas for the optimal solution. However, when as the number of antennas but also computational complexity increase grows too great, limiting its application. Antennas are coded fractionally channel capacity maximizing coding is used as a basic criterion in this paper, and an intelligent algorithm Particle swarm algorithm, generic algorithm are used to pick antennas. The simulation results show that both algorithms are capable of performing antenna selection.

<p>In this paper, a complementary metal oxide semiconductor (CMOS) instrumental amplifier was designed and implemented in order to provide the possibility of controlling the current and voltage gain. The proposed instrumentation amplifier consists of three conveyors with active resistor. The parasitic resistance value (Rx) was reduced with a large bandwidth level in addition to achieving a high common mode rejection ratio (CMRR). Simulation was performed by using 0.35μm CMOS technology by using the advanced design system (ADS) software. The results obtained prove that the proposed circuit has a good efficiency with higher degree of CMRR in comparison with other amplifiers designed and implemented in other similar works.</p>

The reliability and service life of power cables is closely related to the cable ampacity and temperature rise in the power cable. In a conductor carries AC current, complex processes may appear, which directly affect the temperature of the conductor surface. So, to keep a conductor in a good state, it is necessary to maintain the conductor temperature in a acceptable value. In this paper, a procedure for measuring the temperature of conductor surface and the corresponding numerical processing of measurement results has been presented. The measurement of the temperature probe characteristics and the temperature measurement on the surface of the conductor, both required the use of certain numerical methods, such as interpolation and fitting of the measured values in time diagrams. The procedure was applied to three copper conductors with different cross section area and one aluminum conductor and the final results are presented graphically, in the form of time diagrams.

<span lang="EN-US">In this paper, we investigated the effect of magnetic field on the carrier transport phenomenon in metal-oxide-semiconductor field-effect transistor (MOSFET) with double gates by examining the behavior of the semiconductor under the Lorentz force and a constant magnetic field. Various behaviors within the channel have been simulated including the potential distribution, conduction and valence bands, total current density, total charge density and the magnetic field. The results obtained indicate that this modulation affects the electrical characteristics of the device such as on-state current (I_ON), subthreshold leakage current (I_OF), threshold voltage (V_Th), and the Hall voltage (V_H) is induced by the magnetic field. The change in threshold voltage caused by the magnetic field has been observed to affect the switching characteristics of the device, such as speed and power loss, as well as the threshold voltage V_Th and (I_ON/I_OF) ratio. Note that it is reduced by 10-3 V. 102 for magnetic fields of ±6 and ±5.5 tesla respectively.</span>

A B S T R A C TThe aim of this paper is to analyze the influence of adding serial inductance in AC side of the 3ph -6 pulse bridge rectifier on the reduction of harmonic distortion rate. A simulated model with serial inductance was analyzed. The 3-phase 6-pulse diode bridge rectifier was chosen because it corresponds to the operation of the 6-pulse thyristor bridge rectifier at maximum load (while keeping the angle α = 0). Both the total harmonic distortion (THDi) and the power factor (PF) for the circuit have been measured. The results obtained of the THDi has been recorded for four values of serial inductance and results was compared with the (IEEE 519-1992) standard.Comparison results indicates that for values of inductive reactance (Xi) up to 67% cause a reduction of THDi which is above the standard values, while for (Xi) more than 67% cause a reduction in THDi within the acceptable standard level. Analyzing of results prove that the adding of serial inductance at the AC side leads to good reduction in harmonic distortion rate, but with some reduction in power factor value, which results in some energy losses.