JOURNAL OF ENERGY MANAGEMENT
Year:2015 | Volume:5 | Issue:3|Papers Count:6

In this paper, the combined and new methods in distribution network with distributed generation are introduced to allocate fixed cost fairly that is applicable for radial network. Allocation of fixed cost based MW-mile is not fairer method. Fixed cost allocated based on average or peak consumed power using MW-mile that is not fairer method. It is essential to a new method introduced. Unfair pricing under a power profile conditions is shown. Distributed generation (DG) resources can provide benefits to distribution and transmission networks and receive a reward charge. Allocation of DG reward must be fairly. Allocation of DG reward can be based on power loss reduction of loads therefore a new method is introduced and tested on 8-bus distribution network.

This paper is treated with major risks applied by lightning strikes to wind farms. The risks illustrated in this research include overvoltage caused by direct and indirect effects of lightning strikes on any components of wind farm. As demands for electrical energy throughout our world is increased more and more nowadays, wind power plants are extended in every possible locations correspondingly with high isochronic level. So it’s why lightning strikes have come to be important to study. Also as wind farms grow rapidly throughout the world, the grounding system and ground impedance of wind turbine towers under transients have got more important. As a matter of fact, an exact model to testify dynamic properties of grounding system should represent nonlinear effects of soil ionization and be frequency dependent. Some new researches conducted in this issue, all are based circuit theory which does not allow for accurate analysis of aforementioned behaviors. This paper has come to express a new approach to model any grounding system only by few RLC branches in wide frequency range.A new model and some simple formula that is recommended in this work, represent all effects of transient phenomena of lightning strikes and all analysis have got more easier than other approach. By using this method, there’s no difference between those grounding system buried in cylindrical soils or conical one, multi-layer oil or not, humid soil or not and so on, they all are available for transient analysis. Then the outputs of antenna theory and recommended method are compared and finally the RLC branches are implemented in EMTP and get analyzed. So it’s possible to evaluate power systems under lightning strikes with presence of wind farms. Although previous researchers have analyzed some harmful overvoltages created by lightning strikes, but only few of them have reached reasonable outputs. To evaluate some appropriate results, a technical package of simulation must hire first. In this paper some new models of wind farm components such as wind turbine with an interconnecting transformer, different configurations of wind farms, real grounding system with soil ionization based on traveling waves are implemented in Electro-Magnetic Transient Program (EMTP) and some practical case studies are illustrated, too.Due to the complexity of the abovementioned effects, from Electromagnetics point of view, some perfect analysis of overvoltage in wind farms with different configurations is required. Finally the simulations are conducted by RV version of EMTP and evaluated

In this work, chitosan and carboxy methyl cellulose biopolymers were used as gelling agents in composition of electrolyte of dye sensitized solar cells. The effect of both biopolymers on performance of dye sensitized solar cell were investigated by adding the same amounts of two biopolymers to the liquid electrolytes composed of ox/red couple of I-/I3- with similar concentrations. The electrochemical Impedance spectroscopic studies and photovoltaic measurements showed the cell composed of carboxy methyl cellulose as gelling agent had more efficiency than the chitosan cell.

The mentioned paper provides a new approach in the design, modeling and evaluation of vanadium redox flow batteries with polymer membrane. Vanadium redox flow batteries have been proposed as one of the advanced technologies in energy storage systems. This study is based on transient conditions of performance modeling of a battery cell. The proposed time-dependent model has developed based on comprehensive electrochemical, mechanical, fluid and electrical circuit relations along with the concept of taking reasonable assumptions, constraints and appropriate boundary conditions. The results of modeling explain the behavior of different variables such as the concentration of vanadium oxides, the rate of state of change and produced voltage in the battery operating time.On the other hand, the performed parametric study on battery variables represents a significant effect on temperature and initial concentration of the electrolyte solution on the output voltage.

Radiators are common devices for heating of home and office spaces and have a close relationship with the energy sector. In a radiator, heat transfer is increased with increasing of air flow rate along heated surface as well as temperature difference between bulk air and heated surface. First, in order to find the optimum design of an Aluminum radiator numerical analysis of free convection heat transfer using commercial software Fluent was performed and then to thermal evaluation of it the Iranian national standard 4022 which is accordance with international standard ISO 3148 is used as reference experiment. In according to the standard, the test room includes a double room: interior and exterior chamber.The radiator is placed inside the chamber and the exterior chamber is cooled using cooled air. Here, three sets of experimental test are performed at different average of inlet and outlet water temperature of 80 ± 5, 65 ± 5 and 50 ± 5 °C. The average temperature of the interior testing room is controlled by 20 thermocouples mounted in the test room to be maintained in the range of 19 to 21 °C.Experimental results of the radiator heat rate were compared with numerical analysis and good consistency between results was found.

In this study, Exergy and energy analysis of processes of the steel production in Bouyersanat steel industry that contains three stages, melting in induction furnace, preheating and continuous casting is carried out. After doing exergy and energy balance of three stages separately, amount of energy transferred with different way and their shares, exergy losses for each stage and their shares and energy and exergy efficiency are calculated, and finally the overall process has been evaluated.By discussion of the results solutions among preheating of input materials to EIF, Increasing of amount of deoxidization materials like Coke and High carbon ferro manganese, and drafting a proper lid for preheating process are suggested.