In this paper, a novel risk-based, two-objective (technical and economical) optimal reactive power dispatch method in a wind-integrated power system is proposed which is more consistent with operational criteria.  The technical objective includes the minimization of the new voltage instability risk index. The economical objective includes cost minimization of reactive power generation and active power loss. The proposed voltage instability risk employs a hybrid possibilistic (Delphi-Fuzzy)-probabilistic approach that takes into consideration the operator’s experience, the wind speed and demand forecast uncertainties when quantifying the risk index. The decision variables are the reactive power resources of the system. To solve the problem, the modified multi-objective particle swarm optimization algorithm with sine and cosine acceleration coefficients is utilized. The method is implemented on the modified IEEE 30-bus system. The proposed method is compared with those in the previously published literature, and the results confirm that the proposed risk index is better at estimating the voltage instability risk of the system, especially in cases with severe impact and low probability. In addition, according to the simulation results compared to typical security-based planning, the proposed risk-based planning may increase the security and economy of the system due to better utilization of system resources.

This paper proposes an idea to modify the conventional Wilkinson power dividers to have physically spaced output ports. The well-known internal resistor of Wilkinson power divider is now connected to output ports by two additional transmission lines to create a triangular shape power divider. Several modified power dividers are designed at frequency of 1.0 GHz and one of them is fabricated and measured. The measured results of the fabricated diplexer have very good agreement with the theoretical results.

In this study, the design and construction of a pulse high repetition rate (HRR), transverse atmospheric pressure (TEA) CO2 laser with ultra violet preionization is presented. In this laser, normal pure, industrial gases and also a combination of spark and corona preionization are used. In semi-sealed off condition, we obtained 220 watts at 300 Hz, %7.7 efficiency, 735 mJ/pulse. The best records that we reached separately were 1.1 J/pulse, 320 Hz PRR, 11 MW peak power and 10.6% efficiency.

In this work a copper chloride laser has been constructed and the effects of different parameters such as CuCl vapor pressure, buffer gas pressure, voltage and frequency on the output power and the ratio of green to yellow power at different buffer gas pressure have been measured. Thus, by optimization of these parameters and by the exact control of the copper chloride vapor pressure as a result of increasing the distance between discharge and the lasant, a maximum specific output power of 123 (watt/lit) has been achieved. Based on the previous references, the reported specific output power in this work is the highest one among all of the copper halide lasers that have been constructed up to now, where the system is operating without any additives, like hydrogen.

Design and realization of a broadband H-plane Substrate Integrated Waveguide (SIW) power divider with equal and unequal output powers is presented. The configuration of the proposed structure is based on the three equal width SIW lines. In proposed SIW power divider septum has been realized with a row of metalized vias. The inclusive input bandwidth in the proposed structures is achieved due to the proper septum design. The output powers are controlled with the septum offset. The parametric analysis shows that the magnitude of outputs could be adjusted with septum offset and the width of SIW could control the cutoff frequency. Power flow from input port toward output port confirm the proposed design concept. Two SIW H-plane power dividers with the same and different outputs have been designed and produced. There are good agreements between simulation and measurement results for both structures. The input impedance bandwidth for equal and unequal prototypes is 3. 4 GHz and 2 GHz respectively.

The reflex triode is one of the varieties of vircators that are among several types of high power microwave sources. The Main application of these tubes is the disruption of enemy systems by creating a strong electromagnetic field on the target. This paper presents a comparison of experimental and simulation results of a reflex triode. Experimental and simulation results are in good agreement. The software used for simulation is the CST STUDIO SUITE. It is based on the Finite Integration Technique (FIT) and includes a particle in cell code. In previous studies, with the use of two disk-shaped and strip reflectors in this tube, the electric field output was increased by a maximum of 126%. In this research for the first time with the introduction and use of wall reflector, the electric field output was increased by 193%. It was shown that each of the disk-shaped, strip, and wall reflectors increased 37% and 29% of the output electric field, respectively. A variation in the position of the reflector causes a variation in the radiation power. This variation is periodic.

In this paper, a new high step-up current-fed LLC resonant DC-DC converter with a center-tapped transformer is proposed. By selecting the switching frequency to be lower than, but near to, the series resonant frequency of the LLC resonant tank, soft-switching operation of all semiconductors, i.e., zero voltage switching (ZVS) turn-on of power MOSFETs and zero current switching (ZCS) turn-off of diodes is achieved. This leads to lower electromagnetic interference (EMI) and lower switching losses and improves the converter efficiency. An interleaved structure is used at the primary side. Thus, input current ripple is smaller, and its frequency is twice the switching frequency. Consequently, a smaller input filter is necessary in practice. The converter with 1.2 kW output power and 760 V regulated output voltage with 80-200 V input voltage variations is simulated. The output voltage is regulated by using asymmetric pulse width modulation (APWM) at 200 kHz switching frequency. Finally, a 700-W prototype has been implemented and experimental results are also presented to verify the simulation results.

The main methodology in every wind power prediction model involves converting wind speed into power using the power output curve of the wind turbine. However, preceding studies that have introduced models for such curves have not considered the impact of wind direction and its recurring fluctuations over time on predicting wind turbine power output. The main focus of these studies has just been on the magnitude of wind speed and the relationship between wind speed and turbine power. The present study models the effect of wind direction on wind turbine power output and uses it to modify the quadratic power curve equations. Using these modified equations and considering the turbine mechanism to follow the wind direction, a method is presented for predicting wind turbine power output under frequent changes in wind direction over time. To deal with the lack of access to long term and high-resolution wind data, registered historical data and probabilistic distribution functions are used to produce lost data with software. To demonstrate the efficacy of the suggested approach, the real data recorded for a 1.5 MW turbine installed in Khaf in Razavi Khorasan, Iran, are used as a case study. Finally, the potential wind power and potential income of the four windy regions in Iran were assessed based on the payment mechanism of the Organization of Renewable Energy and Electricity Efficiency of Iran, assuming the same installed capacity. The effect of wind direction and its variations over time, which can affect power output of wind turbine and income, is the main focus of this section of paper.

This paper focuses on the development of a Graphical User Interface (GUI) and Artificial Neural Network (ANN) for the prediction of photovoltaic (PV) power output. PV power is generated based on the time, location, and surrounding climate conditions. Therefore, solar power generation predictions using computational methods are needed since the changing weather, which will impact the output power will not generate according to its rating. The objectives of this research are to predict photovoltaic power output at Universiti Tun Hussein Onn Malaysia (UTHM), develop an ANN configuration that can perform the prediction of solar power generation, and design GUI system that can both perform the calculations of power generation and ANN. In order to test the efficiency and reliability, MATLAB software has been used to develop the GUI and ANN, and the output is compared with the proposed mathematical equations. The real data as input data was obtained from the PV solar panel located at GSEnergy Focus Group fertigation site. The GUI with user-friendly features and ANN have been successfully designed and developed which can perform daily prediction of solar power output. On top of that, the results have shown that the ANN predictions are more precise to the real data than the GUI.