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No 42
Vol. 42 No. 14
2018
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Considering the importance of renewable energy in solving the energy crisis and air pollution, in this article, the underlying factors and the dimensions of green jobs are identified and analyzed. In this research, grounded theory (field theory) was used with purposive sampling (snowball) and theoretical saturation criterion. Semi-structured interviews with 50 experts were used for collecting data. Using the indicators and its components, a researcher-made questionnaire was distributed among the suppliers of wind energy businesses. According to the results, the jobs that lead to solving the critical environmental energy and air pollution, have the necessary indicators required for greenness. Five types of jobs in the filed of wind energy were introduced green, but their degree of greenness was different, and were classified according to the importance of being green.
maryam larijani - Ladan Razi kordmahaleh
Keywords : Wind Energy ، Grounded Theory ، Green Job ، Green Degree and Renewable Energy
The Cuckoo Search algorithm (CS) is introduced in this paper for installing optimal Power System Stabilizers (PSSs) designed in a multi-machine power system. The problem of setting the PSSs parameter is formulated as an optimization problem solved by CS algorithm. A special value based on the objective function including the damping ratio and the damping factor of the lightly damped electromechanical modes, is considered for the PSSs design problem. The performance of the proposed CS based PSSs (CSPSS) has been compared with Genetic Algorithm (GA) based PSSs (GAPSS) and the Conventional PSSs (CPSS) under different operating conditions and disturbances. The results of CSPSS have been developed through time-domain analysis, special values and performance indicators. Also, the effect of the proposed algorithm in providing good damping characteristics has been confirmed.
Mehdi Sabri
Keywords : Power system stabilizer (PSS) ، Conventional PSSs (CPSS) ، Genetic algorithm based PSSS (GAPSS) ، Cuckoo search based PSSs (CSPSS) ، The integral of absolute value of the error (IAE) ، The integral of the time multiplied absolute value of the error (ITAE)
Today, extensive research is being done on advanced control methods for a semi-active suspension system. Efforts are being made to achieve more safety for passengers and comfortable driving. On the other hand, the presence of disturbances and uncertainties in the dynamical systems are inevitable, and the uncertain suspension of the car will not be excluded. In this paper, a control structure consisting of sliding mode control, fuzzy logic method and predictive filter has been proposed that has high resistance in confrontation with road disturbances and uncertainty in dynamical system. Improving the performance of sliding mode controller by intelligently selecting its parameters with the help of fuzzy logic and using a powerful predictor in the refinement of uncertain damaged data system can be regarded as the innovation of the proposed algorithm. Simulation results show the optimal performance of a semi-active suspension system in the presence of road disturbances and uncertainties
Mojtaba Masoumnezhad
Keywords : Semi-active suspension ، Sliding mode control ، Fuzzy logic ، Predictive filter ، Uncertainty
The CIGS thin film solar cells are one of the best choices for converting solar energy to electricity. They are extremely noticed by researchers for their high efficiency and low cost of construction. In this study, the performance and factors affecting the efficiency of solar cells have been investigated. The change in the thickness of the layers and the different values of the molar ratio of gallium are two effective factors in increasing the yield. The various parameters of the structure have been improved with the use of the Silvaco simulation software (Atlas) to provide the maximum possible returns for the structure. Therefore, in this research the efficiency of the solar cell is investigated by considering some of the most important cell curves after examining various conditions such as layer thickness variations (CIGS absorbent layer, transparent layer ZnO, CdS layer). Design of a multilayer cell with two or three different acceptor (and Ga) concentrations can have a significant effect on increasing the efficiency of these cells. The simulation results have been analyzed using theoretical relationships as well as physically, which was increased by about 5.9% compared with the original cell model and confirmed the accuracy of the structure simulation. In the end, the voltage-current curve of the base cell is plotted and extracted numerically and graphically using the TonyPlot sub-module and compared with the references. These results also suggest further characterizations to be made for the CIGS layers and the complete solar cells.
Meraj Rajaee
Keywords : Optimization ، Efficiency ، Simulator SILVACO ، Thin layer cells CIGS ، Gallium molar ratio
In recent years, the demand for electrical energy has been rising steadily, whilst the expansion of transmission lines and increased energy production capacity due to environmental and system constraints do not increase as much as this increase in demand. This rapid increasing in load demand forces power systems to operate near the critical limits due to economic and environmental constraints. FACT controllers such as SVC and TCSC are used for enhancing performance of power systems in terms of voltage/angle stability while improving the power transfer capability and voltage profile in steady state conditions. Finding the best location of FACTS devices make these as powerful tool for its aims. In this paper, we determine the location of SVC and TCSC for increasing the static voltage stability in buses by using fuzzy counter. This suggested way is tested by using both Matlab software and Matpower on networks with 14 and 30 IEEE buses, and acceptable results have been achieved. The continuous static load distribution (cpf) method was used to study the static stability of the voltage using the Newton-Raphson method
mohammadali alipour
Keywords : Fuzzy Counter ، FACT Controller ، Static Stability of Voltage ، Continuous Load Distribution ، Newton ، Raphson Method ، Flexible AC

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