JOURNAL OF ENERGY MANAGEMENT
Year:2011 | Volume:1 | Issue:1|Papers Count:7

Distributed generation has recently received a great deal of attention in Iran, as a result of which CHP systems have been employed more, due to their higher efficiency. This article, aims to optimize the system size considering the operating strategy of an industrial case study. Size and operating strategy for the steam boilers are optimized. The problem has been solved by using GAMS software to optimize the Net Present Value (NPV) of the plant from the plant owner’s point of view. A sensitivity analysis has also been performed to illustrate the optimal solutions variation caused by altering several key parameters such as fuel and electricity prices.

Distribution networks reconfiguration, capacitor placement and distributed generation resources placement are three methods of loss reduction, used in many studies. Individual optimization, without considering their mutual effect, result in suboptimal answer in these works. In this paper, a new method is presented for simultaneous optimization of place and size of DG and capacitors as well as the network configuration, aiming for minimum loss. Simulation results of implementing the method on a 30 bus network indicate the importance of considering these three parameters together in such studies. Also, by using the numerical result of simulations, the reconfiguration of distribution network and placement of capacitors in presence of DG have been analyzed numerically, where the effect of each parameter is illustrated.

In this paper, a real time method is introduced for distribution networks reactive power control in order to co-ordinate all equipments contributing to improved voltage profile and reduced losses and costs. Imperialist Competitive Algorithm (ICA) is also employed for optimization purposes. The proposed method was implemented on a part of Tehran distribution network, which confirmed its effectiveness.

In recent years, appearance of Distributed Generation (DGs) in power systems networks has provided important implications. Important advantages of DGs include increased reliability, loss reduction and improving voltage profile. In case of failure in the network, DGs can provide islands (isolated networks) resulting in continuation of supply loads and may reduce the number and/or duration of interruptions for customer residing within their protection zones. In this article, using a combination of Ant Colony system (ACS) algorithm, Analysis Hierarchical Process (AHP) and sensitivity analysis, optimal placement of reclosers and DGs are carried out based on economic and power quality considerations. The cost function include improving reliability, voltage profile and network losses. The method was implemented on a modified 34-feeder IEEE distribution network. Simulation results validated the effectiveness of the proposed method.

Economic dispatch as an important problem in production management and power system operation, is studied here with a view to improve realistic simulation, considering practical limitations such as valve point effect, ramp rate limits, prohibited operating zones, multiple fuel sources and power transmission losses. Hence, a new optimization method is proposed based on modified shuffled frog leaping algorithm, the efficiency and validation of which is demonstrated by comparing the simulation results in different test systems. These comparisons reveal the superiority and robustness of the proposed method.

The positive effects of renewable energies have forced many countries to draw attention to clean environmentally friendly energy sources such as wind. However, the first step for harnessing the wind energy is to locate regions with good potential for turbine installation. The use of wind energy to provide steady and reliable supply of electricity is on the increase. In this work, Weibull probability density function was employed to analyze the wind speed data collected between 2007 and 2008 by the Iranian Renewable Energy Organization from two meteorological stations at north Khorasan province in Iran. The results obtained in this study demonstrated that for the city of Bojnoord, the wind power density at 30 and 40m heights were 200 and 250 W/m2, respectively, while for the city of Esfarayen, these were 200 and 300 W/m2.The study indicates that wind farm projects are feasible in both of these cities.

Considering problems associated with nonrenewable fuels such as pollution and high cost, efforts are being made to develop use of renewable energy sources like solar energy. Solar collectors could often be employed as important devices for thermal applications. Unglazed Transpired Collector (UTC) is a modern preheating and heating equipment used for ventilating air or drying crops. Heat transfer in the UTC is accomplished by passing air through holes of the unglazed collector. In this study, the effect of wind stream parallel to the collector surface on its performance is investigated using numerical techniques. The study is based on total energy balance where new equations are incorporated in order to consider the wind effect. The results show that increasing the wind velocity may decrease or increase the collector efficiency depending on the incoming air approach velocity. This is due to opposite effects of wind and radiation heat losses with convection heat transfer from collector surface to inlet air. Moreover, the heat exchange effectiveness increases with increasing the wind velocity for any approach velocity.